[go: up one dir, main page]
More Web Proxy on the site http://driver.im/

WO2007055392A1 - Ionic compound - Google Patents

Ionic compound Download PDF

Info

Publication number
WO2007055392A1
WO2007055392A1 PCT/JP2006/322693 JP2006322693W WO2007055392A1 WO 2007055392 A1 WO2007055392 A1 WO 2007055392A1 JP 2006322693 W JP2006322693 W JP 2006322693W WO 2007055392 A1 WO2007055392 A1 WO 2007055392A1
Authority
WO
WIPO (PCT)
Prior art keywords
mentioned
ionic
ionic compound
lithium
acid
Prior art date
Application number
PCT/JP2006/322693
Other languages
French (fr)
Inventor
Keiichiro Mizuta
Taisuke Kasahara
Yoichi Arimoto
Hironobu Hashimoto
Kazuo Takei
Hiromoto Katsuyama
Original Assignee
Nippon Shokubai Co., Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2005328032A external-priority patent/JP5066334B2/en
Priority claimed from JP2006271962A external-priority patent/JP5224675B2/en
Application filed by Nippon Shokubai Co., Ltd. filed Critical Nippon Shokubai Co., Ltd.
Publication of WO2007055392A1 publication Critical patent/WO2007055392A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D233/00—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings
    • C07D233/54—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D233/00—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings
    • C07D233/54—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members
    • C07D233/56—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, attached to ring carbon atoms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/54—Electrolytes
    • H01G11/56—Solid electrolytes, e.g. gels; Additives therein
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G9/00—Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
    • H01G9/20—Light-sensitive devices
    • H01G9/2004—Light-sensitive devices characterised by the electrolyte, e.g. comprising an organic electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0569—Liquid materials characterised by the solvents
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/542—Dye sensitized solar cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Definitions

  • the present invention relates to an ionic compound. More specifically, thepresent invention relates to: an ionic compound which is preferable as a material for ionic conductors constituting electrochemical devices; an ionic composition containing such an ionic compound; and a battery prepared using such an ionic compound and/or such an ionic composition.
  • Ionic compounds are composed of a cation and an anion and have been widely used in various applications .
  • substances having ionic conductivity are preferably used, as an electrolyte, in constituent materials of ionic conductors which are essential in various ion conductive batteries.
  • the constituent materials of ionic conductors can function as an electrolyte and/or a solvent in electrolytic solutions constituting the ionic conductors, or can function as a solid electrolyte.
  • Examples of the applications include electrochemical devices such as: batteries having charge and discharge mechanisms such as primary batteries, lithium (ion) secondary batteries, and fuel batteries; electrolytic condensers; electric double layer capacitors; and solar cells and electrochromic display devices.
  • each battery is generally constituted of a pair of electrodes and an ionic conductor occurring therebetween.
  • ionic conductors are electrolytic solutions preparedby dissolving an electrolyte, such as lithium perchlorate, LiPF 6 , LiBF 4 , tetraethylammonium fluoroborate or tetramethylammonium phthalate, in an organic solvent such as ⁇ -butyrolactone, N, N-dimethylformamide, propylene carbonate or tetrahydrofuran.
  • an electrolyte such as lithium perchlorate, LiPF 6 , LiBF 4 , tetraethylammonium fluoroborate or tetramethylammonium phthalate
  • organic solvent such as ⁇ -butyrolactone, N, N-dimethylformamide, propylene carbonate or tetrahydrofuran.
  • the electrolyte when dissolved, dissociates into a cation and an anion to cause ionic
  • FIG. 1 shows a cross sectional view schematically showing one embodiment of a conventional lithium (ion) secondarybattery .
  • a lithium (ion) secondary battery has a positive electrode and a negative electrode each formed of an active substance, and an electrolytic solution constituted of an organic solvent and a lithium salt such as LiPF 6 dissolved as a solute in the solvent, forms an ionic conductor between the positive and negative electrodes.
  • the reaction C ⁇ Li -> 6C + Li + e " occurs on the negative electrode
  • the electron (e ⁇ ) generated on the negative electrode surface migrates through the electrolytic solution to the positive electrode surface in the manner of ionic conduction.
  • the reaction CoO 2 + Li + e ⁇ ⁇ LiCoO 2 occurs and an electric current flows from the negative electrode to the positive electrode.
  • reverse reactions as compared with those during charging occur, and an electric current runs from the positive electrode to the negative electrode .
  • Japanese Kohyo Publication No. 2000-508676 (pages 2 to 13, and 39 to 67) discloses an ionic compound containing at least one anionic part bonded to at least one cationic part M, wherein M is hydroxonium, nitrosonium, NO + , ammonium, NH 4 + , a metal cation having a valency of m, an organic cation, or an organic metal cation; and the anion part has a five-membered ring structure or derived from tetraazapentalene.
  • the Example discloses, as the anionic part, derivatives of triazole, imidazol, and cyclopentadiene .
  • Japanese Kokai Publication No . 2004-331521 (pages 2 and 3) discloses an ionic liquid containing a
  • N-alkylimidazolium cation or an ammonium cation, and a tetrazole anion or a triazole anion have room for improvement in order to be preferably used in various applications 'such as materials constituting electrochemical devices and exhibit excellent basic performances.
  • Halogen-containing lithium salts such as LiClO 4 , LiN(SO 2 CFa) 2 , LiN(SO 2 C 2 Fs) 2 , LiSO 3 CF 3 , LiSO 3 C 2 F 5 , LiBF 4 , LiPF 6 , and LiAsF 5 arementioned as generallyused compounds as an electrolyte (ionic conductor) for lithium batteries.
  • halogen-containing lithium salts have been insufficient in stability, safety, or conductivity needed as an electrolyte for lithium batteries. That is, if these lithium salts are used as an electrolyte for lithium batteries and the like, it is known that leakage of an electrolytic solution or deterioration thereof caused by the halogen is caused, and the solution may leak.
  • Ionic conductive materials having high conductivity that are anion salts having a five-membered ring have been investigated.
  • CA2194127 pages 89 and 99 discloses lithium dicyanotriazolate not containing halogen, as one example of this anion salt containing a five-membered ring.
  • Electrochemical and Solid-StateLetters, egashira, etal., 2003, Vol.6, No.4, andp. A71-A73 discloses lithiumdicyanotriazolate as a lithium salt of a polyethylene oxide-based polymer electrolytic solution.
  • diaminomaleonitrile 200 mmol is added to an aqueous solution 250 mL adjusted to an acid solution with hydrochloric acid 200 mmol to prepare slurry.
  • One equivalent amount of sodium nitrite is added to this slurry under stirring while the temperature is maintained at O 0 C to obtain a brown reaction mixture.
  • This reaction mixture is filtered and subjected to extraction three times with ether.
  • the extract is evaporated and then the ether is evaporatedby drying to obtain coarse dicyanotriazole (HDCTA) .
  • HDCTA coarse dicyanotriazole
  • Thus-obtained coarse HDCTA is sublimed two times at 80°C to obtain purified HDCTA.
  • this HDCTA is treated with a slightly excess amount of lithium carbonate to obtain a turbid solution.
  • This solution is subjected to centrifugal separation.
  • the obtained supernatant liquid is dried under reduced pressure to obtain LiDCTA.
  • this lithium dicyanotriazolate also has room for improvement in order to exhibit high charge and discharge properties needed as an electrolyte for lithium batteries for a more prolonged period.
  • the present invention has been made in view of the above-mentioned state of the art.
  • the present invention has an object to provide: an ionic compound which can exhibit excellent basic performances such as electrochemical stability and can be preferably used in various applications such as materials for electrochemical devices; a composition containing such an ionic compound; and a battery prepared using such an ionic compound and/or an ionic composition.
  • the present inventors have made various investigations on ionic compounds.
  • the inventors noted that triazolate anion having triazole as an anion skeleton. Triazolate is a unique anion having a ring structure, and triazolate has low acidity singly and therefore needs to be improved.
  • the inventors found that if two cyano groups (-CN) are introduced as a substituent, into triazolate to form dicyanotriazolate anion, such dicyanotriazolate anion has increased electric adsorption due to the introduction of two cyano groups, and therefore can be stabilized. They have also found that if the ionic compound containing such anion contains a specific cation having a monovalent element or an organic group, such an ionic compound can be easily dissolved in a matrix (solvent and the like) as compared with inorganic salts, and that if such an ionic compound contains an alkali metal ion, such an ionic compound can exhibit excellent basic performances such as high ionic conductivity and high stability.
  • the inventors also found that if a moisture content, and an excess acid amount or an excess base amount, or a content of an amidated product are specified in such an ionic compound, the ionic compound can prevent side reaction with an electrode or deterioration of an electrolyte while exhibiting excellent charge and discharge properties needed as an electrolyte for lithium batteries and the like, which permits practical use of electrochemical devices such as lithium batteries having prolonged reliability.
  • an ionic composition which contains an ionic compound satisfying a specific excess acid amount or excess base amount, and has a specific moisture content also permits practical use of electrochemical devices such as lithium batteries having prolonged reliability. As a result, the above-mentioned problems have been admirably solved.
  • the present inventors found that if such an ionic compound or ionic composition contains no fluorine atom, due to the absence of the fluorine atom, corrosivity on electrodes and the like can be suppressed, which permits stable function over time.
  • the inventors also found that such an ionic compound and ionic composition can function as a liquid material constituting an electrolytic solution and can be preferably applied in various applications such as materials for electrochemical devices. Thereby, the present invention has been completed.
  • the present invention relates to an ionic compound having: a moisture content of 1000 ppm or less; and an excess acid amount or an excess base amount of less than 0.2 * 10 "3 mol/g, wherein the ionic compound comprises a dicyanotriazolate anion and at least one cation selected from the group consisting of cations represented by the following formula (1) : Rs L ( 1 )
  • L representing at least one element selected from the group consisting of C, Si, N, P, S, and 0; R being the same or different and each representing a monovalent element or an organic group, and may be bonded together; and s being an integer of 3 to 5 and being a value determined by the valency of the element L) and alkali metal ions.
  • the present invention also relates to an ionic compound comprising a dicyanotriazolate anion, wherein the ionic compound contains 1.5% by weight or less of an amidated product of the dicyanotriazolate anion.
  • the present invention includes an ionic compound comprising a dicyanotriazolate anion and a cation represented by the above formula (1) .
  • the present invention also relates to an ionic composition comprising an ionic compound and having a moisture content of 1000 ppm or less, wherein the ionic compound has an excess acid amount or an excess base amount of less than 0.2 * 10 "3 mol/g.
  • the present invention also relates to a battery prepared using the ionic compound and/or the ionic composition.
  • Fig.1 shows a cross-sectional view schematically showing one embodiment of a lithium secondary battery.
  • Fig. 2 (a) is a perspective view showing one embodiment of an electrolytic condenser.
  • Fig. 2 (b) is a perspective view showing one embodiment of an aluminum electrolytic condenser.
  • Fig. 3 is a cross-sectional view schematically showing one embodiment of an electric double layer capacitor and an enlarged view of the electrode surface.
  • Fig. 4 is a 1 H-NMR chart of EMImDCTA obtained in Example Fig . 5 is a 3 C-NMR chart o f EMImDCTA obtained in Exampl e
  • Fig. 6 is a 1 H-NMR chart of TEADCTA obtained in Example 2.
  • Fig. 7 is a 13 C-NMR chart of TEADCTA obtained in Example
  • Electrolyte (Electrolytic solution) Li salts, such as LiPF
  • the ionic compound of the present invention contains a cation and an anion, and has: a moisture content of 1000 ppm or less; and an excess acid amount or an excess base -amount of less than 0.2 * 10 "3 mol/g.
  • the above-mentionedmoisture content is amoisture content relative to a weight of solids of the ionic compound, and preferably 1000 ppm or less.
  • the moisture content is more preferably 800 ppm or less, and still more preferably 500 ppm or less, and furthermore preferably 200 ppm or less.
  • the ionic compound 0.2 g is dissolved in dehydrated methanol 1.8 g.
  • This solution is measured for moisture content (A ppm) using the Karl Fischer method.
  • the dehydrated methanol used for preparing this solution is also measured for moisture content (Bppm) using theKarl Fischermethod.
  • themoisture content (C ppm) of the ionic compound is calculated from the following formula 1.
  • C (A x (1.8 + 0.2))-B x 1.8/0.2 (formula 1)
  • a state where the contents of the cation and the anion in the ionic compound are the same is defined as basis
  • a state where the content of the cation is smaller than that of the anion is defined as "state where the acids are excessive” and the degree is represented by "excess acid amount”.
  • a state where the contents of the cation and the anion are the same in the ionic compound is defined as a basis
  • a state where the content of the cation is larger than that of the anion is defined as "state where the bases are excessive” and the degree is representedby “excess base amount” .
  • the above-mentioned excess acid amount or the above-mentioned excess base amount of the ionic compound is preferably less than 0.2 * 10 ⁇ 3 mol/g, and more preferably 0.18 x 10 "3 mol/g or less.
  • the above-mentioned excess acid amount or the above-mentioned excess base amount can be measured as follows. "Measurement of excess acid amount or excess base amount"
  • the ionic compound 0.1 g is dissolved in distilled water 9.9 g to prepare a 1% by weight aqueous solution of the ionic compound. This solution is measured for pH with a commercially available pH meter. The solution is subjected to neutralizing titration with a 0.1 M aqueous solution of sodium hydroxide if showing a pH of 7 or less in the measurement. While the pH is measured, the volume of the 0. IM aqueous solution of sodium hydroxide needed until the point of inflection is defined as "V ml", and the excess acid amount X mol/g is calculated from the following formula.
  • the solution is subjected to neutralizing titration with 0.1 M hydrochloric acid if showing a pH of more than 7 in this measurement. While the pH is measured, the volume of the 0. IM aqueous solution of sodium hydroxide needed until the point of inflection is defined as "V ml", and the excess base amount
  • Y mol/g is calculated from the following formula.
  • Y 0.1 x f x V/1000/1.0 (f: potency of hydrochloric acid) If the 1% by weight aqueous solution of the ionic compound has a pH of 6 to 8, the pH is lowered to 6 or less by adding 0.1 N hydrochloric acid to the solution. Then, the solution may be subjected to titration with a 0.1 N aqueous solution of sodium hydroxide. In this case, the volume of the 0.1 N hydrochloric acid firstly added is defined as V H (potency: f H ) and the volume of the 0.1 N aqueous solution of sodium hydroxide added until the point of inflection is definedasV Ne (potency : f Ne ) .
  • the functional effects of the present invention of providing an ionic compound which exhibits excellent basic performances such as electrochemical stability and can be preferably used in various applications such as electrochemical devices may be insufficiently exhibited. That is, as mentioned below, lithium with very high reactivity is generated on the negative electrode during discharging.
  • the ionic compound has a Hazen value of 200 or less.
  • the ionic compound more preferably has a Hazen value of 180 or less.
  • the Hazen value can be measured as follows. "Measurement of Hazen value"
  • the ionic compound 0:1 g is dissolved in distilled water 9.9 g to prepare a 1% by weight aqueous solution of the ionic compound.
  • This solution is measured for Hazen value by comparing the hue with that of a Hazen standard sample by eye observation. In this measurement, the aqueous solution of the ionic compound and the Hazen standard sample are charged into equivalent containers, respectively and compared with each other.
  • the above-mentioned ionic compound contains 1.5% by weight or less of an amidated product.
  • the content is more preferably 0.5% by weight or less, and still more preferably 0.3% by weight or less, and most preferably 0.2% by weight or less. If the content of the amidated product is more than 1.5% by weight, an irreversible reaction generates inert components on the electrode surface, which affects the electrochemical properties . That is, the irreversible reaction occurs on the Li-foil electrode surface in the evaluation test of reactivity with the Li-foil electrode if the content of the amidated product is more than 1.5% by weight. As a result, deposits may be generated.
  • the irreversible reaction generates inert components inside the electrode in the charge and discharge test using a coin battery.
  • the discharge capacity after a certain charge and discharge cycle test may be reduced or the resistance between the electrodes may be increased.
  • the ionic compound contains an amidated product of the dicyanotriazolate anion within the above-mentioned value range, that is, the ionic compound contains the amidated product of preferably 1.5% by weight or less, and more preferably 0.5% by weight or less, and still more preferably 0.3% by weight or less, and most preferably 0.2% by weight or less.
  • the above-mentioned content of the amidated product can be measured as follows. "Determination method of amidated product"
  • the above-mentioned ionic compound has an impurity content of 0.1% by weight (1000 ppm) or less in 100% by weight of the ionic compound. If the ionic compound is more than 0.1% by weight, the electrochemical stability may be insufficiently obtained.
  • the impurity content is more preferably 0.05% by weight or less, and still more preferably 0.01% by weight or less.
  • the above-mentioned impurity does not contain water, and examples thereof include impurities which are mixed in upon preparation of the ionic compound. Specifically, if an ionic compound essentially containing dicyanotriazolate anion is produced by deriving a halogen compound, for example, the halogen compound may be mixed as an impurity.
  • the silver salt may be mixed as an impurity.
  • Production raw materials, byproducts, and the like also may be mixed as impurities.
  • the impurity content in the ionic compound is determined as mentioned above in the present invention, for,example, it becomes possible to sufficiently suppress deterioration of performances due to poisoning of an electrode in an electrochemical device by the halogen compound, or sufficiently suppress deterioration of performances due to influence of the silver ion or the like on the ionic conductivity.
  • the impurity content is preferably measured by the following measurement method. (Measurement method of impurities)
  • ICP measurement of cations such as silver ion and iron ion
  • Instrument ICP light emitting spectrophotometry apparatus called SPS4000 (manufactured by Seiko Instruments Inc.)
  • Detector electric conductivity detector called CD-20 Column: AS4A-SC Method: A sample 0.3 g is 100-fold diluted with ion-exchanged water, and the resulting solution is measured.
  • the above-mentioned ionic compound contains a cation and an anion.
  • the above-mentioned cation is preferably at least one cation selected from the group consisting of cations represented by the following formula (1) and alkali metal ions.
  • L representing at least one element selected from the group consisting of C, Si, N, P, S, and 0; R being the same or different and each representing a monovalent element or an organic group, and may be bonded together; and s being an integer of 3 to 5 and being a value determined by the valency of the element L) .
  • anion is preferably dicyanotriazolate anion and representedby the following formula
  • the triazole ring contains two cyano groups, the electric absorption increases and the acidity can be higher. Therefore, such an anion can be sufficiently stabilized.
  • the ionic compound may contain anions other than the above-mentioned dicyanotriazolate anion, or cations other than the above-mentioned cation.
  • the ionic compound of the present invention contains the above-mentioned cation containing a monovalent element or an organic group and the dicyanotriazolate anion. Therefore, the ionic compound can be easily dissolved in a matrix (solvent and the like) as compared with inorganic salts such as lithium salts . Therefore, such a compound can be excellent in various physical properties and can be preferably applied in various applications such as materials for electrochemical devices.
  • the present invention includes an ionic compound containing a dicyanotriazolate anion and the cation represented by the above formula (1).
  • the ionic compound of the present invention can exhibit excellent basic performances such as electrochemical stability if containing an alkali metal ion and the dicyanotriazolate anion . Therefore, such an ionic compound can be preferably used in various applications such as materials for electrochemical devices .
  • L represents at least one element selected from the group consisting of C, Si, N, P, S, and 0.
  • L is preferably an element of N, P, and S, and more preferably an element of N.
  • the above-mentioned R are the same or different and each represent a monovalent element or an organic group, and may be bonded together.
  • Preferred examples of the above-mentioned monovalent element or the above-mentioned organic group include hydrogen element, fluorine element, amino group, imino group, amide group, ether group, ester group, hydroxyl group, carboxyl group, carbamoyl group, cyano group, sulfone group, sulfide group, vinyl group, C 1 to C 18 hydrocarbon group, and C 1 to C 18 fluorocarbon group.
  • Each of the above-mentioned C 1 to C 18 hydrocarbon group and the above-mentioned C 1 to C 18 fluorocarbon group may have a straight chain, a branched chain, or a ring structure, and may contain a nitrogen element, an oxygen element, and a sulfur element. Such groups preferably contain 1 to 18 carbon atoms, and more preferably 1 to 8 carbon atoms. More preferred examples of the above-mentioned monovalent element or the above-mentioned organic group include hydrogen element, fluorine element, cyano group, sulfone group, C 1 to C 8 hydrocarbon group, oxygen atom-containing C 1 to C 8 hydrocarbon group, and C 1 to C 8 fluorocarbon group. Still more preferred is hydrogen element. As mentioned above, the preferable embodiments of the present invention include such an ionic compound wherein at least one of R in the above formula (1) is hydrogen element.
  • s is an integer of 3 to 5 and a value determined by the valency of the element L. If L is C or Si, s is 5. If L is N or P, s is 4. If L is S or 0, s is 3. That is, cations represented by the following formula (1-1) :
  • the above-mentioned cation is not especially limited as long as it satisfies the above-mentioned formula (1) .
  • onium cations represented by the following (I) to (IV) are more preferable.
  • the onium cation means an organic group having a cation of a non-metal element such as O, N, S and P or a semi-metal element.
  • R 4 to R 15 are the same or different and each represent a monovalent element or an organic group and may be bonded together.
  • R 4 to R 15 are the same or different and each represent a monovalent element or an organic group and may be bonded together.
  • onium cations More preferred among such onium cations are those in which L in the above formula (1) is nitrogen element. Still more preferred are six species of onium cations represented by the following formula (1-2) (in the formula, R 4 to R 15 are the same as those mentioned above) and chain onium cations such as triethylmethylammonium, dimethyIethylpropylammonium, diethylmethylmethoxyethylammonium, trimethylpropylammonium, trimethylbutylammonium, and trimethylhexylammonium.
  • formula (1-2) in the formula, R 4 to R 15 are the same as those mentioned above
  • chain onium cations such as triethylmethylammonium, dimethyIethylpropylammonium, diethylmethylmethoxyethylammonium, trimethylpropylammonium, trimethylbutylammonium, and trimethylhexylammonium.
  • Preferred examples of the above-mentioned monovalent element or the above-mentioned organic group in R to R include hydrogen element, fluorine element, amino group, imino group, amide group, ether group, ester group, hydroxyl group, carboxyl group, carbamoyl group, cyano group, sulfone group, sulfide group, vinyl group, C 1 to C 18 hydrocarbon group, and C 1 to C 18 fluorocarbon group.
  • Each of the above-mentioned C 1 to C 18 hydrocarbon group and the above-mentioned C 1 to C 18 fluorocarbon group may have a straight chain, a branched chain, or a ring structure, and may contain a nitrogen element, an oxygen element, and a sulfur element.
  • Such groups preferably contain 1 to 18 carbon atoms, and more preferably contain 1 to 8 carbon atoms.
  • More preferred examples of the above-mentioned monovalent element or the above-mentioned organic group include hydrogen element, fluorine element, cyano group, sulfone group, C 1 to C 8 hydrocarbon group, oxygen atom-containing C 1 to C 8 hydrocarbon group, and C 1 to C 8 fluorocarbon group.
  • Ionic composition containing such a molten salt can be preferably used as a material for ionic conductors of electrochemical devices capable of enduring long-term use .
  • the molten salt means a salt capable of retaining its liquid state stably at temperatures of 80 0 C or less.
  • the above-mentioned ionic compound containing the dicyanotriazolate anion and the cation represented by the above formula (1) preferably has an embodiment (1) the compound essentially contains a nitrogen heterocyclic cation having a conjugated double bond, or an embodiment (2) in the above formula (I) / L is N, and R are the same or different and each represent a hydrogen atom or R 1 to R 3 representing a C l to C 8 hydrocarbon group.
  • the nitrogen heterocyclic cation having a conjugated double bond preferred are the cations having a conjugated double bond, in which L is nitrogen element in the above formula (1), among ten species of heterocyclic onium cations of the above-mentioned (I) and five species of unsaturated onium cations of the above-mentioned ( H ) •
  • R 1 to R 3 are hydrocarbon groups
  • these hydrocarbon groups may be directly bonded to each other, or may have a structure in which the groups are bonded with at least one element selected from the group consisting of O, S, and N therebetween.
  • the present invention also includes an ionic compound containing a dicyanotriazolate anion and a cation represented by the following formula (3) :
  • R 1 to R 3 being the same or different and each representing hydrogen element or a C 1 to C 8 hydrocarbon group; if at least two of R 1 to R 3 being hydrocarbon groups, these hydrocarbon groups may be directly bonded or may have a structure in which the groups are bonded with at least one element selected from the group consisting of 0, S, and N therebetween) . It is preferable that such an ionic compound also satisfies at least one of the preferable value ranges in the above-mentioned various physical properties (moisture content, excess acid amount or excess base amount, Hazen value, and amidated product content) . With respect to the cation contained in the ionic compound of the present invention, the alkali metal ion is not especially limited.
  • Examples thereof include lithium ion, sodium ion, potassium ion, rubidium ion, caesium ion, and francium ion. Among them, it is preferable that at least lithium ion is contained. As a result, the ionic conductivity, the electrochemical stability, or the like can be sufficiently improved.
  • Such an ionic compound containing lithium ion and dicyanotriazolate anion is also referred to as "lithium dicyanotriazolate” .
  • the present invention also relates to an ionic compound comprising a dicyanotriazolate anion, wherein the ionic compound contains 1.5% by weight or less of an amidated product of the dicyanotriazolate anion.
  • the dicyanotriazolate anion is as mentioned above. If the content of the amidated product of the anion is more than 1.5% by weight, an irreversible reaction generates inert components on the electrode surface, which affects the electrochemical properties. That is, the irreversible reaction occurs on the Li-foil surface in the evaluation test of reactivity with the Li-foil electrode if the content of the amidated product is more than 1.5% by weight. As a result, deposits may be generated. Even if no deposits are generated on the Li-foil surface in the evaluation test of reactivity with the Li-foil electrode, the irreversible reaction generates inert components inside the electrode in the charge and discharge test using a coin battery.
  • the above-mentioned content of the amidated product is preferably 0.5% by weight or less, and more preferably 0.3% by weight or less, and still more preferably 0.2% by weight or less .
  • the above-mentioned content of the amidated product can be measured as mentioned above.
  • the above-mentioned ionic compound preferably satisfies the above-mentioned value ranges in various physical properties such as moisture content, excess acid amount or excess base amount, and Hazen value.
  • a cation contained in the above-mentioned ionic compound preferred is at least one cation selected from the group consisting of cations represented by the above formula
  • Lithium ion is more preferred.
  • the preferable embodiments of the present invention include an embodiment in which the above-mentioned ionic compound contains a lithium ion.
  • the above-mentioned lithium dicyanotriazolate is a compound having a structure represented by the following formula (7) .
  • lithium dicyanotriazolate As a particularly preferable embodiment of the above-mentioned lithium dicyanotriazolate is an embodiment in which the lithium dicyanotriazolate has: a moisture content of 1000 ppm or less; and an excess acid amount or an excess base amount of less than 0.2 * 10 "3 mol/g.
  • the functional effects of the present invention of providing an ionic compound which exhibits excellent basic performances such as electrochemical stability and can be preferably used in various applications can be sufficiently exhibited.
  • the production method of the ionic compound of the present invention is not especially limited.
  • a method including a step of deriving an ionic compound from a compound containing dicyanotriazolate anion (for example, dicyanotriazole) is preferable.
  • the ionic compound has a form preferable as a molten salt or a salt constituting a solid electrolyte.
  • Such a production method preferably includes a step of deriving an ionic compound from a compound having a dicyanotriazolate anion structure using a halide or a carbonated product.
  • a metal atom selected from the group consisting of alkali metal atoms, alkaline earthmetal atoms, transitionmetal atoms and rare earth metal atoms.
  • an anion exchange resin is preferably used in the above-mentioned production method.
  • the above-mentioned production method may include a step of synthesizing the compound containing dicyanotriazolate anion used in the above-mentioned step of deriving an ionic compound from a compound containing dicyanotriazolate.
  • the compound containing dicyanotriazolate anion is preferably synthesizedby reacting the above-mentioned compound containing dicyanotriazolate anion with a halide or a carbonated product.
  • the anion contained in the compound containing the anion which is a production raw material used in the step of synthesizing the compound containing dicyanotriazolate anion is not the same as the dicyanotriazolate anion contained in the ionic compound.
  • dicyanotriazole (HDCTA) is used as the above-mentioned compound containing dicyanotriazolate anion
  • the step of synthesizing the HDCTA is preferably as follows.
  • the above-mentioned step of synthesizing HDCTA includes the steps of : synthesizing dicyanotriazole (HDCTA) bydispersing diaminomaleonitrile into an acid aqueous solution and adding sodium nitrite into the dispersion solution; adding an organic solvent into the solution after the reaction to perform extraction; andpurifying the extractedsubstance to obtainHDCTA.
  • Examples of the above-mentioned acid aqueous solution used for dispersing diaminomaleonitrile include aqueous solutions prepared by dissolving the following compounds in water.
  • Mineral acids such as sulfuric acid, hydrochloric acid, hydrogen bromide, nitric acid, and phosphoric acid; halogenated carboxylic acids such as chloroacetic acid, dichloroacetic acid, trichloroacetic acid, and trifluoroacetic acid; and sulfonic acids such as methansulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and dodecylbenzenesulfonic acid.
  • halogenated carboxylic acids such as chloroacetic acid, dichloroacetic acid, trichloroacetic acid, and trifluoroacetic acid
  • sulfonic acids such as methansulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and dodecylbenzenesulfonic acid.
  • An aqueous solution prepared by dissolving sulfuric acid in water is preferable in view of preventing corrosion of a reaction kettle,
  • the above-mentioned diarainomaleonitrile preferably accounts for 5 to 70%, andmore preferably 10 to 50% relative to the reaction mixture .
  • the addition amount of the above-mentioned sodium nitrite is preferably 1.00 to 1.15 times greater than the amount of HDCTA. Thereby, the Hazen value of the ionic compound of the present invention can be effectively reduced.
  • the addition amount is more preferably 1.03 to 1.12 times.
  • the sodium nitrite may be added in solid form or in aqueous solution form.
  • the sodium nitrite is added in aqueous solution form.
  • dicyanotriazole (HDCTA) is synthesized and then an organic solvent is added to the reaction liquid to perform the extraction.
  • HDCTA dicyanotriazole
  • the above-mentioned solvent used for the extraction is not limited.
  • Preferred examples thereof include ether solvents such as diisopropyl ether, diethyl ether, dipropyl ether, methylbutyl ether, and dibutyl ether; solvents containing an ether group or an ester group derived from ethylene glycols or propylene glycols, for example, cyclic ethers such as tetrahydrofuran and dioxane, dimethoxyethane, methyl cellosolve, ethyl cellosolve, and methoxy propylene glycol; ketone solvents such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, ethyl butyl ketone, ethyl isobutyl ketone, and cyclopentanone; ester solvents, such as ethyl acetate, propyl acetate, and butyl acetate.
  • ether solvents such as diethyl ether, dipropyl ether, diisopropyl ether, methylbutyl ether, and dibutyl ether; and ester solvents such as ethyl acetate, propyl acetate, and butyl acetate.
  • ester solvents such as ethyl acetate, propyl acetate, and butyl acetate.
  • the sublimation temperature is preferably 120 to 130°C in view of reduction in sublimation time. If the sublimation temperature is more than 130°C, side reaction such as decomposition or amidation of HDCTA may occur, which is not preferable .
  • the sublimation temperature is more preferably 123 to 127°C.
  • the sublimation pressure is preferably 50 Pa or less, and more preferably 30 Pa or less.
  • the number of times of the sublimination of the HDCTA is not especially limited.
  • the sublimination of the HDCTA is preferably preformed one time in view of economical efficiency.
  • the preferable embodiments of the present invention include an embodiment in which the above-mentioned ionic compound is synthesized using HDCTA purified by sublimation.
  • the molar number of the compound containing dicyanotriazolate anion is represented by "a” and the. molar number of the halide is represented by "b", the molar ratio (a/b) in the reaction is preferably 100/1 to 0.1/1. If the above-mentioned compound containing dicyanotriazolate anion is less than 0.1, the halide is excessive, which may fail to generate a product effectively. In addition, the halogen may be mixed in the ionic composition and thereby electrodes and the like may be poisoned. If the above-mentioned compound containing dicyanotriazolate anion is more than 100, the compound is excess and therefore improvement in yield may not be expected any more. In addition, the metal ion is mixed in the ionic composition and thereby performances of electrochemical devices may be reduced. The molar ratio is preferably 10/1 to 0.5/1.
  • the reaction conditions in the above-mentioned step may be appropriately determined depending on the production raw materials, other reaction conditions, and the like.
  • the reaction temperature is preferably -20 to 200°C, and more preferably 0 to 100°C, and furthermore preferably 10 to 60°C.
  • the reaction pressure is preferably 1 * 10 2 to 1 * 10 8 Pa, and more preferably 1 * 10 3 to 1 * 10 7 Pa, and still more preferably 1 x 10 4 to 1 x 10 6 Pa.
  • the reaction time is preferably 48 hours or less, and more preferably 24 hours or less, and still more preferably 12 hours or less.
  • a reaction solvent is usually used.
  • reaction solvent examples include (1) aliphatic hydrocarbons such as hexane and octane; (2) alicyclic saturated hydrocarbons such as cyclohexane; (3) alicyclic unsaturated hydrocarbons such as cyclohexne; (4) aromatic hydrocarbons such as benzene, toluene and xylene; (5) ketones such as acetone and methyl ethyl ketone; (6) esters such as methyl acetate, ethyl acetate, butyl acetate and ⁇ -butyrolactone; (7) halogenated hydrocarbons such as dichloroethane, chloroform and carbon tetrachloride; (8) ethers such as diethyl ether, dioxane and dioxolane; (9) ethers of alkylene glycols such as propylene glycol monomethyl ether acetate and diethylene glycol monomethyl ether acetate; (10) alcohols such as
  • One or two or more species of them may be used.
  • preferred are the solvents mentioned in (5) , (6) , (10) , (11) , (12), (13), (14), (15) , and (16) . Morepreferredare the solvents mentioned in (5), (10), (15), and (16).
  • the above-mentioned ionic compound is lithium dicyanotriazolate
  • the above-mentioned step is preferably performed as follows.
  • the above-mentioned step of synthesizing lithium dicyanotriazolate is preferably a step of synthesizing lithium dicyanotriazolate (LiDCTA) by adding a lithiation reagent to HDCTA and drying the synthesized lithium dicyanotriazolate.
  • the lithiation reagent include lithium carbonate, lithium hydroxide, and lithium metal. Lithium carbonate is preferably used because lithium carbonate with high purity is commercially available and therefore easily obtained.
  • the reaction temperature is preferably 50 0 C or less . If the reaction temperature is more than 50°C, the cyano groups are additionally reacted with water to generate byproducts.
  • the solvent used in the above-mentioned step of synthesizing LiDCTA is not especially limited. The following two preferable embodiments may be mentioned in reaction of HDCTA with an equivalent amount of the lithiation reagent. One is a method using water as the solvent . Thereby, HDCTCA is reacted with an equivalent amount of the lithiation reagent to complete the reaction in one stage. In this case, the reaction is preferably completed at pH of 6 to 8 as a terminal point.
  • the acids or the bases excessively remain in the system despite use of water, which is not preferable.
  • the other method is a method using a solvent other than water.
  • the reaction is not completed when HDCTA is reacted with an equivalent amount of the lithiation reagent, and the acids or the bases may remain in the system.
  • the reaction is preferably completed at pH of 6 to 8 as a terminal point. If the pH is lower than 6 or higher than 8, the acids or the bases more excessively remain in the system despite use of water, which is not preferable. In this case, the excess acids or bases can be removed by purification after the reaction.
  • the above-mentioned ionic composition essentially containing the ionic compound may be obtained by the following method: the generatedprecipitate is filtered to obtain a solvent containing the ionic compound; the solvent is removed under vacuum or the like condition; the obtained substance is washed by dissolved in a solvent such as dichloromethane; the washed substance is dehydrated by adding a substance having dehydration effect such as MgSO 4 thereto; and the dehydrated substance is dried under reduced pressure after removal of the solvent.
  • the number of times of the detergency with the solvent may be appropriately determined.
  • Preferred examples of the solvent include: ketones such as chloroform, tetrahydrofuran, and acetone; ethers such as ethylene glycol dimethyl ether; acetonitrile; and water, in addition to dichloromethane.
  • Preferred examples of the substance having dehydration effect includemolecular sieve, CaCl 2 , CaO, CaSO 4 , K 2 CO 3 , active alumina, and silica gel, in addition to MgSO 4 .
  • the addition amount of such a substance may be appropriately determined depending on the kind of the product or the solvent.
  • purification may be performed if necessary.
  • the purification method is not especially limited. Examples thereof include activated carbon treatment, extraction, and crystallization eachusing a solvent which can dissolve the ⁇ onic compound therein.
  • Examples of the method of the above-mentioned drying of the ionic compound include reduced pressure drying, fluidized bed drying, solvent azeotropydrying, spray drying, andmolecular sieve drying. These methods may be employed singly or in combination.
  • solvents used in the solvent azeotropy include ether solvents such as toluene, hexane, cyclohexane, diethyl ether, dipropyl ether, diisopropyl ether, methylbutyl ether, tetrahydrofuran, dioxane, 1, 2-dimethoxyethane; nitrile solvents, such as acetonitrile and propionitrile; alcohol solvents such as ethanol, propanol, isopropanol, and butanol; ketone solvents, such as acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, ethyl butyl ketone, ethyl isobutyl ketone, and cyclopentanone; ester solvents, such as methyl acetate, ethyl acetate, propyl ether
  • Dehydrated solvents are preferably used as the above-mentioned solvent in view of drying rate.
  • the method of dehydrating the solvent is not especially limited. A dehydration method using a molecular sieve may be mentioned.
  • the azeotropy temperature is preferably 40°C or more and 140°C or less. If the azeotropy temperature is lower than 40 0 C, the azeotropic composition formed of water and the azeotropic solvent shifts to the azeotropic solvent, and therefore the drying efficiency is reduced, which is not preferably.
  • the azeotropy temperature of more than 140 0 C is not preferable because the above-mentioned byproducts causing the amidation may be extremely generated.
  • the following method is mentioned as a preferable embodiment of efficiently performing the azeotropic dehydration while suppressing the generation of the above-mentioned amidated products. That is, a method of performing dehydration at low temperatures in an initial dehydration step in which the reaction system has a large moisture content and then raising the temperature while confirming the amount of reduced moisture in the system.
  • the time needed for such an azeotropic dehydration step is not especially limited. It is preferable that the azeotropic dehydration is performed for a proper time while confirming the moisture amount in the system. If the azeotropic dehydration time is short, the ionic compound is not dried until a desired moisture amount, which is not preferable. If the azeotropic dehydration is too long, residual moisture allows the amidation reaction to proceed, which is not preferable.
  • the above-mentioned ionic compound is dissolved in a solvent and treated by addition of a commercially available molecular sieve . Then, the solvent is dried. As a result, the moisture in the above-mentioned ionic compound can be reduced.
  • Examples of the above-mentioned solvent in which the ionic compound is dissolved include methanol, ethanol, n-propanol, isopropanol, n-butanol, s-butanol, t-butanol, acetone, methyl ethyl ketone, acetonitrile, and propylene carbonate.
  • the solvent is selected depending on use conditions of ' the above-mentioned ionic compound because a step of drying such a solvent is needed.
  • the molecular sieve added is not especially limited. Commercially available various molecular sieves may be used. However, it is preferable that the molecular sieve is selected depending on use conditions of the above-mentioned ionic compound because elution from the molecular sieve may occur . If the ionic compound is used for lithiumbatteries, Li-Aand the like obtained from UNION SHOWA K. K., in which the sodium constituting the molecular sieve is substituted with lithium is preferably used.
  • the above-mentioned drying of the ionic compound is performed by molecular sieve and toluene azeotropy. Thereby, the above-mentioned moisture amount in the ionic compound can be effectively reduced.
  • the drying temperature is preferably 140°C or less. If the drying temperature is more than 140 0 C, the above-mentioned byproducts causing the amidation reaction may be extremely generated.
  • a particularly preferable embodiment as the above-mentioned production method of the ionic compound is an embodiment in which the production method includes the steps of : synthesizing a compound containing dicyanotriazolate anion; synthesizing an ionic compound containing the anion; and drying the ionic compound. That is, the above-mentioned ionic compound is preferably produced by the production method including these steps .
  • the above-mentioned various ionic compounds of the present invention have the above-mentioned configuration. Therefore, such ionic compounds can exhibit excellent basic performances such as electrochemical stability and can be particularly preferable as amaterial for ionic conductors of electrochemical devices capable of enduring long-term use .
  • the preferable embodiments of the present invention include an ionic composition containing the above-mentioned ionic compound preferably used as a material for ionic conductors.
  • the above-mentioned ionic composition may contain an onium cation-containing organic compound other than the above-mentioned organic salts essentially containing onium cations .
  • Organic compounds containing an onium cation and the following anion may be mentioned as such an onium cation-containing organic compound.
  • Halogen anions fluoro anion, chloro anion, bromo anion, iodo anion
  • a borate tetrafluoride anion a phosphate hexafluoride anion, an aluminate tetrafluoride anion, an arsenate hexafluoride anion, a sulfonylimide anion represented by the following formula (4), a sulfonylmethide anion represented by the following formula (5)
  • organic carboxylic acids anions of acetic acid, trifluoroacetic acid, phthalic acid, maleic acid, benzoic acid and the like
  • fluorine-containing inorganic ions such as a hexafluorophosphoric acid ion, a hexafluoroarsenic acid ion, a hexafluoroantimonic acid ion, a hexafluoroniobic acid ion, and a hexafluorotantalic acid ion; carboxylic acid ions such as a hydrogen phthalate ion, a hydrogen maleate ion, a salicylic acid ion, a benzoic acid ion, and an adipic acid ion; sulfonic acid ions such as a benzenesulfonic acid ion, a toluenesulfonic acid ion, a dodecylbenzenesulfonic acid ion, a trifluoromethanesulfonic acid ion, and a perfluorobutanesulfonic acid ion; inorganic
  • R 16 , R 17 , and R 18 may be the same or different and each represent a C 1 to C 4 perfluoroalkyl group which may optionally have one or two ether groups.
  • the lower limit is preferably 0.5 mol, and more preferably 0.8 mol, relative to the above-mentioned anion 1 mol.
  • the upper limit is preferably 2.0 mol, and more preferably 1.2 mol.
  • the above-mentioned ionic composition may contain an alkali metal salt and/or an alkaline earth metal salt.
  • Such an ionic composition containing an alkali metal salt and/or an alkaline earth metal salt contains the alkali metal salt and/or the alkaline earth metal salt as an electrolyte, and preferably serves as a material for ionic conductors of electrochemical devices.
  • Such an alkali metal salt includes lithium salts, sodium salts and potassium salts.
  • Such an alkaline earth metal salt includes calcium salts and magnesium salts. Lithium salts are more preferred.
  • the above-mentioned alkali metal salt and/or the above-mentioned alkaline earth metal salt may be an ionic compound essentially containing the above-mentioned anion or may be a compound other than the ionic compound.
  • Alkali metal salts and/or alkaline earth metal salts of dicyanotriazolate anion are preferable if the above-mentioned alkali metal salt and/or the above-mentioned alkaline earthmetal salt are/is the above-mentioned ionic compound (s) essentially containing the anion.
  • lithium salt of dicyanotriazolate anion maybe usedas the above-mentionedalkali metal salt and/or the above-mentioned alkaline earth metal salt .
  • Lithium salts may be used as other alkali metal salts and/or alkaline earth metal salts .
  • Preferable examples of such lithium salts include LiC (CN) 3 , LiSi (CN) 3 , LiB (CN) 4 , LiAl (CN) A , LiP (CN) 2 , LiP(CN) 6 , LiAs(CN) 6 , LiOCN, and LiSCN.
  • Electrolyte salts showing a high dissociation constant in an electrolytic solution or a polymer solid electrolyte are preferable in compounds other than the above-mentioned ionic compound.
  • Preferred examples thereof include alkali metal salts and alkaline earthmetal salts of trifluoromethanesulfonic acid such as LiCF 3 SO 3 , NaCF 3 SO 3 and KCF 3 SO 3 ; alkali metal salts and alkaline earth metal salts of perfluoroalkanesulfonimide, such as LiN (CF 3 SO 3 ) 3 and LiN (CF 3 CF 3 SO 2 ) i) alkali metal salts and alkaline earth metal salts of hexafluorophosphoric acid, such as LiPF 6 , NaPF 6 and KPF 6 ; alkali metal salts and alkaline earth metal salts of perchloric acid, such as LiClO 4 and NaClO 4 ; tetrafluoroborate salts such as LiBF 4
  • LiPF 6 , LiBF 4 , LiAsF 6 , and alkali metal salts or alkaline earth metal salts of perfluoroalkanesulfonimide are preferred in view of solubility and ionic conductivity.
  • the above-mentioned ionic composition may contain another electrolyte salt.
  • Preferred examples thereof include perchloric acid quaternary ammonium salts such as tetraethylammonium perchlorate; tetrafluoroboric acid quaternary ammonium salts such as (C 2 Hs) 4 NBF 4 , quaternary ammonium salts such as (C 2 Hs)-(NPF 6 ; and quaternary phosphonium salts such as (CH 3 ) 4 P-BF 4 , and (C 2 HB) 4 P-BF 4 .
  • Quaternary ammonium salts are more preferred in view of solubility and ionic conductivity.
  • the lower limit is 0.1% by weight and the upper limit is 50% by weight in 100% by weight of the ionic composition. If the amount is less than 0.1% by weight, the absolute ion amount is insufficient, possibly leading to a low ionic conductivity. If the amount is more than 50% by weight, the migration of the ions maybe greatly inhibited.
  • the upper limit is more preferably 30% by weight. If the above-mentioned ionic composition contains aproton, such an ionic composition can be preferably used as a material for ionic conductors constituting hydrogen batteries.
  • the proton can occur in the ionic composition of the present invention if the ionic composition contains a compound capable of generating a proton upon dissociation.
  • the lower limit is 0.01 mol/L, and the upper limit is 10 mol/L. If the amount is less than 0.01 mol/L, the absolute proton amount may be insufficient, possibly leading toa lowprotonic conductivity . If the amount is more than 10 mol/L, the migration of the protons may be greatly inhibited.
  • the upper limit is more preferably 5 mol/L or less.
  • the above-mentioned ionic composition is solidified if containing a polymer.
  • a solidified composition can be preferably used as a polymer solid electrolyte.
  • the ionic conductivity is more improved.
  • polystyrene, polyphosphazenes, polysiloxane, polysilane, polyvinylidene fluoride, polytetrafluoroethylene, polycarbonate polymers, and ionene polymers examples include polyvinyl polymers such as polyacrylonitrile, poly (meth) acrylic acid esters, polyvinyl chloride, and polyvinylidene fluoride; polyoxymethylene; polyether polymers such as polyethylene oxide, and polypropylene oxide; polyamide polymers such as nylon 6, and nylon 66; polyester polymers such as polyethylene terephthalate; polystyrene, polyphosphazenes, polysiloxane, polysilane, polyvinylidene fluoride, polytetrafluoroethylene, polycarbonate polymers, and ionene polymers .
  • the lower limit is 0.1% by weight and the upper limit is 5000% by weight relative to 100% by weight of the ionic composition. If the amount is less than 0.1% by weight, the effect attributed to the solidification may be insufficiently improved. If the amount is more than 5000% by weight, the ionic conductivity may be reduced.
  • the lower limit is more preferably 1% by weight and the upper limit is more preferably 1000% by weight.
  • Solvents capable of improving the ionic conductivity are used as the above-mentioned solvent.
  • Water, organic solvents, and the like are preferably used, for example.
  • the above-mentioned organic solvents preferably used are compounds having: better compatibility with the above-mentioned components in the ionic composition; a large dielectric constant; a high solubility in the electrolyte salt; a boiling point of 60 0 C or more; and a wide electrochemical stable range .
  • Organic solvents having a low moisture content (non-aqueous solvents) are more preferred.
  • organic solvents include ethers such as 1, 2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, crown ether, triethylene glycol methyl ether, tetraethylene glycol dimethyl ether, anddioxane; carbonates such as ethylene carbonate, propylene carbonate, diethyl carbonate, and methylethyl carbonate; chain carbonic acid esters such as dimethyl carbonate, ethylmethyl carbonate, diethyl carbonate, diphenyl carbonate, and methylphenyl carbonate; cyclic carbonic acid esters such as ethylene carbonate, propylene carbonate, ethylene 2, 3-dimethylcarbonate, butylene carbonate, vinylene carbonate, and ethylene 2-vinylcarbonate; aliphatic carboxylic , acid esters such as methyl formate, methyl acetate, propionic acid, methyl propionate, ethyl acetate, propyl
  • N-methylpyrrolidone, and N-vinylpyrrolidone sulfur compounds such as dimethylsulfone, ethylmethylsulfone, diethylsulfone, sulfolane, 3-methylsulfolane, and 2, 4-dimethylsulfolane; alcohols such as ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether; ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, 1,4-dioxane, 1, 3-dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, 2, 6-dimethyltetrahydrofuran, and tetrahydropyran; sulfoxides such as dimethyl sulfoxide, methylethyl sulfoxide, and diethyl sulfoxide; aromatic nitriles such as benzonitrile, and
  • the content of the above-mentioned solvent is preferably 1 to 99% by weight in 100% by weight of the ionic composition. If the content is less than 1% by weight, the ionic conductivity is insufficiently improved.
  • the content is more than 99% by weight, the stability is insufficiently improved due to volatilization of the solvent.
  • the lower limit of the content is preferably 1.5% by weight, and more preferably 20% by weight, and still more preferably 50% by weight.
  • the upper limit of the content is preferably 85% by weight, and more preferably 75% by weight, and still more preferably 65% by weight.
  • the solvent amount is preferably within a range of 50 to 85% by weight .
  • the above-mentioned ionic composition has a reduced volatile content and is not frozen, for example, at a low temperature of -55°C. Further, the ionic composition is excellent in ionic conductivity. Therefore, such an ionic composition can exhibit excellent basic performances if used as an electrolytic solution.
  • the above-mentioned ionic composition may contain one or two or more species of components other than those mentioned above unless the effects of the present invention are sacrificed.
  • the ionic composition may be also used as a composite electrolyte.
  • the solvent is added, a free electrolytic solution is dispersed in the voids in the composite electrolyte .
  • the ionic conductivity and the migration degree can be increased without deteriorating strength-improving effects.
  • Inorganic oxides in minute particle form which show no electronic conductivity and are electrochemically stable are preferable as the above-mentioned inorganic oxides in minute particle form. More preferred are those which show ionic conductivity.
  • Preferable examples of such inorganic oxides in minute particle form include ionic conductive or nonconductive ceramics in minute particle form such as ⁇ , ⁇ , ⁇ -alumina / silica, titania, zirconia, magnesia, barium titanate, titanium oxide, and hydrotalcite.
  • the above-mentioned inorganic oxide in minute particle form preferably has a specific surface area as large as possible in order to increase the amount of the electrolyte-containing solution contained in the above-mentioned ionic composition, thereby increasing the ionic conductivity and the migration degree .
  • the specific surface area is preferably 5 m 2 /g or more, as determined by the BET method, for example.
  • the specific surface area is more preferably 50 m 2 /g ormore .
  • Such an inorganic oxide in minute particle form may have any crystal particle diameter as long as the oxide can be mixed with other components in the above-mentioned ionic composition.
  • the lower limit of the size (average crystal particle diameter) is preferably 0.01 ⁇ m, and the upper limit thereof is preferably 20 ⁇ m. More preferably, the lower limit is 0.01 ⁇ m and the upper limit is 2 um.
  • the above-mentioned inorganic oxide in minute particle form may have various shapes, for example, spherical, oval, cubic, cuboid, cylindrical, or rod-like shape.
  • the above-mentioned inorganic oxide in minute particle form is preferably added such that the upper limit of the added amount is 50% by weight relative to 100% by weight of the above-mentioned ionic composition. If the amount is more than 50% by weight, the strength or the ionic conductivity in the above-mentioned ionic composition may be reduced or a film is difficult to form using the ionic composition.
  • the upper limit is more preferably 30% by weight .
  • the lower limit is preferably 0.1% by weight.
  • the above-mentioned ionic composition may contain various additives in addition to the above-mentioned salts and solvents .
  • the addition of additives has wide-ranging purposes, and examples thereof include improvement in electrical conductivity and in thermal stability, suppression of deterioration of an electrode due to hydration or dissolution, suppression of gas generation, and improvement in withstand voltage and in wettability.
  • additives include nitro compounds such as p-nitrophenol, m-nitroacetophenone, and p-nitrobenzoic acid; phosphorus compounds such as dibutyl phosphate, monobutyl phosphate, dioctyl phosphate, monooctyl octylphosphonate, and phosphoric acid; boron acid or boron compounds such as complex compounds of boric acidwithpolyhydric alcohols (ethylene glycol, glycerin, mannitol, polyvinyl alcohol or the like) or polysaccharides; nitroso compounds; urea compounds; arsenic compounds; titanium compounds; silicic compounds; aluminic acid compounds; nitric acid and nitrous acid compounds; benzoic acids such as 2-hydroxy-N-methylbenzoic acid and di (tri) hydroxybenzoic acid; acids such as gluconic acid, bichromic acid, sorbic acid, dicarboxylic acid, EDTA, fluorocarbox
  • the content of the above-mentioned additive is not especially limited.
  • the content is preferably within a range of 0.1 to 20% by weight inl00%byweightof the ionic composition.
  • the content is more preferably within a range of 0.5 to 10% by weight . It is preferable that the above-mentioned ionic composition has an ionic conductivity at 0°C of 0.5 mS/cm or more.
  • anionic conductor containing the above-mentioned ionic composition may fail to stably function with the lapse of time while retaining an excellent ionic conductivity .
  • the ionic conductivity is more preferably 2.0 mS/cm or more.
  • the ionic conductivity at -55°C is preferably 1 * 10 "7 S/cm or more. If the ionic conductivity is less than 1 x 10 "7 S/cm, an electrolytic solution containing the above-mentioned ionic composition may fail to sufficiently stably function with the lapse of time while retaining an excellent ionic conductivity.
  • the ionic conductivity is more preferably 1 * 10 ⁇ 6 S/cm or more, and still more preferably 5 x 10 "5 S/cm or more, and particularly preferably 1 * 10 "4 S/cm or more.
  • the above-mentioned ionic conductivity can be preferably measuredby complex impedance methods using an impedance analyzer HP4294A (trade name, manufacturedby Toyo Corp . ) , or an impedance analyzer SI 1260 (trade name, manufacturedby Solartron Co . , Ltd. ) , each using SUS electrodes. It is preferable that the above-mentioned ionic composition has a viscosity at 25°C of 300 mP-s or less.
  • the viscosity is more than 300 mPa-s, the ionic conductivity may be improved insufficiently.
  • the viscosity is more preferably 200 mPa • s or less, and still more preferably 100 mPa • s or less, and most preferably 50 mPa-s or less.
  • the measurement method of the above-mentioned viscosity is not especially limited. Preferred is a method of measuring a viscosity at 25°C using a model TV-20 cone/plate type viscometer (product of Tokimec Inc.).
  • the present invention is also an ionic composition comprising an ionic compound and having a moisture content of
  • the ionic compound has an excess acid amount or an excess base amount of less than 0.2 x 10 "3 mol/g.
  • Such an ionic composition also can exhibit excellent basic performances such as electrochemical stability and can exhibit sufficient functional effects of the present invention of being preferably used as a material for ionic conductors of electrochemical devices capable of enduring long-term use.
  • the above-mentioned moisture content of the ionic composition is preferably 1000 ppm or less. If the moisture content is more than 1000 ppm, the electric stability may be insufficiently improved.
  • the moisture content is more preferably 800 ppm or less, and more preferably 500 ppm or less .
  • the moisture content is more preferably 1 ppm or more and more preferably 3 ppm or more in view of easier moisture control. If the above-mentioned ionic composition contains only the above-mentioned ionic compound, the above-mentioned ionic compound satisfies the above-mentioned moisture content value range .
  • the above-mentioned moisture content is preferably measured by the above-mentioned measurement method.
  • the above-mentioned ionic compound contained in the ionic composition has an excess acid amount or an excess base amount of less than 0.2 * 10 "3 mol/g, and contains an anion and a cation. If the excess acid amount or the excess base amount is more than 0.2 x 10 "3 mol/g, as mentioned above, reaction with an active substance of a positive electrode or a negative electrode or deterioration of an electrolyte may be caused if the ionic composition is used as an electrolyte for lithium batteries and the like. Therefore, the functional effects of the present invention of providing an ionic composition which exhibits excellent basic performances such as electrochemical stability and can be preferably used in various applications such as electrochemical devices may be insufficiently exhibited.
  • the excess acid amount or the excess base amount is preferably 0.18
  • Such an ionic compound preferably contains the above-mentioned dicyanotriazolate anion.
  • the cation is preferably at least one cation selected from the group consisting of lithium ion and cations represented by the above formula ( 1 ) .
  • Lithium ion is more preferable.
  • the preferable embodiments of the present invention include an embodiment in which the above-mentioned ionic compound contains a lithium ion (that is, the above-mentioned ionic compound is lithium dicyanotriazolate) .
  • the preferable embodiments or the production method and the like in the ionic compound containing such an anion and cation are as mentioned above .
  • the preferable embodiments and the like of the ionic composition containing the ionic compound are preferably the same as those in the above-mentioned ionic composition.
  • the ionic compound and the ionic composition of the present invention can exhibit the above-mentioned properties, and therefore can be preferably applied in various applications.
  • the ionic compound and the ionic composition are particularly preferable as electrolytes constituting electrochemical devices such as batteries having charge/discharge mechanisms, such as primary batteries, lithium (ion) secondary, batteries and fuel batteries; electrolytic solution for electrolytic condensers; electrolytic condensers; electric double layer capacitors; and solar batteries and electrochromic display devices.
  • the preferable embodiments of the present invention include an electrolyte containing the above-mentioned ionic compound and/or the above-mentioned ionic composition.
  • the preferable embodiments of the present invention also include a battery, an electrolytic solution for electrolytic condensers, an electrolytic condenser, or an electric double layer capacitor, each prepared using the above-mentioned ionic compound and/or the above-mentioned ionic composition.
  • the above-mentioned ionic compound and/or the ionic composition is/are preferably used as an electrolyte, but may be used as materials other then electrolytes.
  • the above-mentioned battery prepared using the ionic compound and/or the anionic composition is preferably a battery having charge and dischargemechanisms such as primarybatteries, lithium (ion) secondary batteries, and fuel batteries. Among them, lithium secondary batteries are particularly preferable.
  • the above-mentioned electrolyte contains the above-mentioned ionic compound and/or the above-mentioned ionic composition, and preferably contains the above-mentioned ionic compound and/or the above-mentioned ionic composition, and a matrix material.
  • the preferable embodiments of the present invention include such an electrolyte containing the above-mentioned ionic compound and/or the above-mentioned ionic composition, and a matrix material.
  • the above-mentioned electrolyte means a material for electrolytic solutions or a material for electrolytes.
  • Such an electrolyte can preferably used in ionic conductors of electrochemical devices as (1) a solvent constituting electrolytic solutions and/or (2) a material for electrolytes (material for ionic conductors), and (3) a material for solid electrolytes (material for electrolytes) .
  • the above-mentioned electrolyte containing the ionic compound and/or the ionic composition constitutes an electrolytic solution (or a solid electrolyte) , together with a substance showing ionic conductivity in the solvent.
  • the above-mentioned electrolyte containing the ionic compound and/or the ionic composition is contained in the solvent to constitute a material for electrolytes.
  • the above-mentioned electrolyte containing the ionic compound and/or the ionic composition serves as a solid electrolyte as it is or after another component is contained in the electrolyte.
  • the above-mentioned matrix material is preferably an electrolyte essentially containing an organic solvent.
  • the above-mentioned organic solvents are preferable.
  • a preferred form of the electrochemical device includes, as basic constituent elements, an ionic conductor, a negative electrode, a positive electrode, current collectors, separators and a container.
  • a mixture of an electrolyte with an organic solvent or a polymer is preferably used as the above-mentioned ionic conductor.
  • This ionic conductor is generally called an "electrolytic solution” if an organic solvent is used and called an “electrolyte” if apolymer solidelectrolyte is used.
  • Polymer solid electrolytes containing anorganic solvent asaplasticizer are included in the polymer solid electrolyte.
  • the above-mentioned electrolyte containing the ionic compound and/or the ionic composition can be preferably used as a substitute for the electrolyte or the organic solvent in the electrolytic solution in such an ionic conductor, and the electrolyte can be preferably used as a polymer solid electrolyte.
  • an electrochemical device prepared using such an electrolyte as a material for the ionic conductor at least one of the materials for the ionic conductor is constituted of the above-mentioned electrolyte. Among them, it is preferable that the electrolyte is used as the substitute for the organic solvent or as the polymer solid electrolyte in the electrolytic solution.
  • the above-mentioned organic solvent may be an aprotic solvent capable of dissolving the above-mentioned electrolyte containing the compound and/or the ionic composition, and the above-mentioned organic solvents are preferable as such an organic solvent.
  • the electrolytic solution is preferably prepared by dissolving the electrolyte in a mixed solvent composed of an aprotic solvent having a permittivity of 20 or more and an aprotic solvent having a permittivity of 10 or less among such organic solvents.
  • the solution has a low solubility in an aprotic solvent having a permittivity of 10 or less, such as diethyl ether or dimethyl carbonate, and therefore a sufficient ionic conductivity can not be obtainedby the solution singly .
  • the solution has a high solubility in an aprotic solvent having a permittivity of 20 or more, but also has a high viscosity. Therefore, the ions are difficult to migrate and also in this case, a sufficient ionic conductivity can not be obtained. If these solvents are mixed together, appropriate solubility and migration degree can be secured and sufficient ionic conductivity can be obtained.
  • polymers which dissolves the abov.e-mentioned electrolyte one or two or more of the above-mentioned polymers can be preferably used.
  • polymers or copolymers having polyethlene oxide as a main chain or a side chain homopolymers or copolymers of polyvinylidene fluoride, methacrylate polymer, and polyacrylonitrile . If a plasticizer is added to these polymers, the above-mentioned aprotic organic solvent may be used.
  • the electrolyte concentration in the above-mentioned ionic conductor is preferably 0.01 mole/dm 3 or more and a saturation concentration or less.
  • the concentration of less than 0.01 mole/dm 3 is undesirable, because the ionic conductivity is low.
  • the concentration is more preferably 0.1 mole/dm 3 or more and 1.5 mole/dm 3 or less.
  • Lithium metal or an alloy of lithium and other metals is preferably used as the material for the above-mentioned negative electrode, in lithium batteries.
  • lithium ion batteries preferred are polymers, organic materials, carbon obtained by baking pitch or the like, natural graphite, and materials which are prepared by phenomenon called intercalation, such as metal-oxide.
  • active carbons preferred are active carbons, porous metal oxides, porous metals, and conductive polymers.
  • lithium-containing oxides such as LiCoO 2 , LiNiO 2 / LiMnO 2 and LiMn 2 O 4 ; oxides such as TiO 2 , V 2 O 5 and MoO 3 ; sulfides such as TiS 2 and FeS; and conductive polymers such as polyacetylene, polyparaphenylene, polyaniline and polypyrrole.
  • activate carbons, porous metal oxides, porous metals and conductive polymers are preferred.
  • Lithium secondary battery Alithium secondarybattery is constitutedof the following basic constituent elements: a positive electrode, a negative electrode, separators occurring between the positive and negative electrodes, and an ionic conductor containing an electrolyte containing the above-mentioned ionic compound and/or the above-mentioned ionic composition.
  • the electrolyte containing the above-mentioned ionic compound and/or the above-mentioned ionic composition contains a lithium salt as a substance showing ionic conductivity.
  • a lithium secondary battery is a nonaqueous electrolyte lithium secondary battery, which is other than an aqueous electrolyte lithium secondary battery.
  • Fig. 1 shows a cross-sectional view schematically showing one embodiment of such a lithium secondary battery.
  • coke is used as a negative electrode active substance mentioned below and a Co-containing compound is used a positive electrode active substance mentioned below.
  • the reaction C 6 Li ⁇ 6C + Li + e occurs on the negative electrode, the electron (e-) generated on the negative electrode surface migrates through the electrolytic solution to the positive electrode surface in the manner of ionic conduction.
  • the above-mentioned negative electrode is preferably produced by applying a negative electrode mixture containing a negative electrode active substance, a conductive agent for negative electrodes, a binder for negative electrodes, and the like to the surface of a current collector for negative electors .
  • the negative electrode mixture may contain various additives in addition to the conductive agent and the binder.
  • Metallic lithium and materials capable of occluding and releasing lithium ions are preferred as the above-mentioned negative electrode active substance .
  • Preferred examples of the above-mentioned materials capable of occluding and releasing lithium ions include metallic lithium; pyrolytic carbons; cokes such as pitch coke, needle coke and petroleum coke; graphite; glassy carbons; organic polymer-derived baking products which are produced by baking phenolic resins, furan resins and the like at an appropriate temperature to convert them into carbon; carbon fibers; carbon materials such as active carbon; polymers such as polyacetylene, polypyrrole and polyacene; lithium-containing transition metal oxides or transition metal sulfides, such as Li 4 Z 3 Ti 5 Z 3 O 4 and TiS 2 ; metals capable of alloying with alkali metals, such as Al, Pb, Sn, Bi and Si; cubic intermetallic compounds capable of intercalating alkali metals, such as AlSb, Mg 2 Si and NiS
  • the above-mentioned conductive agent for negative electrodes is an electron conductive material.
  • Preferred examples thereof include graphites, for example, natural graphites such as scaly graphite, and artificial graphites; carbon blacks such as acetylene black, Ketjen black, channel black, furnace black, lamp black and thermal black; conductive fibers such as carbon fibers and metal fibers; metals such as fluoride carbon, copper, and nickel, in powder form; and organic conductive materials such as polyphenylene derivatives.
  • graphites for example, natural graphites such as scaly graphite, and artificial graphites
  • carbon blacks such as acetylene black, Ketjen black, channel black, furnace black, lamp black and thermal black
  • conductive fibers such as carbon fibers and metal fibers
  • metals such as fluoride carbon, copper, and nickel, in powder form
  • organic conductive materials such as polyphenylene derivatives.
  • artificial graphite, acetylene black and carbon fibers are more preferred.
  • the use amount of the conductive agent for negative electrodes is preferably 1 to 50 parts by weight, and more preferably 1 to 30 parts by weight relative to 100 parts by weight of the negative electrode active substance.
  • the negative electrode active substance has electric conductivity, and therefore such a conductive agent for negative electrodes is not necessarily used.
  • the above-mentioned binder for negative electrodes may be either a thermoplastic resin or a thermosetting resin.
  • binder for negative electrodes include polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubbers, tetrafluoroethylene-hexafluoropropylene copolymers, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers, vinylidene fluoride-hexafluoropropylene copolymers, vinylidene fluoride-chlorotrifluoroethylene copolymers, ethylene-tetrafluoroethylene copolymers, polychlorotrifluoroethylene, vinylidene fluoride-pentafluoropropylene copolymers, propylene-tetrafluoroethylene copolymers, ethylene-chlorotrifluoroethylene copolymers, vinylidene fluoride-hexafluoropropylene- tetrafluoroethylene copolymers,
  • One or two or more of them may be used.
  • styrene-butadiene rubbers polyvinylidene fluoride, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, ethylene-methyl acrylate copolymers, ethylene-methyl methacrylate copolymers; polyamides, polyurethanes, polyimides polyvinylpyrrolidone, and copolymers thereof.
  • the above-mentioned current collector for negative electrodes is an electron conductor not causing any chemical change within the battery.
  • Preferred examples thereof include stainless steel, nickel, copper, titanium, carbon, conductive resins, and copper or stainless steel having a surface on which carbon, nickel, titaniumor the like is adhered or coated.
  • copper and copper-containing alloys are more preferred.
  • One or two or more species of them may be used.
  • the surface of these current collectors for negative electrodes may be oxidized and then used.
  • it is preferable that the surface of the current collector is provided with projections and depressions .
  • the current collector for negative electrodes preferably has a form of a foil, film, sheet, net, punched body, lath, porous body, foamed body, or molded fiber group, for instance.
  • the current collector preferably has a thickness of 1 to 500 ⁇ m.
  • the above-mentioned positive electrode is preferably produced by applying a positive electrode mixture containing a positive electrode active substance, a conductive agent for positive electrodes, a binder for positive electrodes and the like to the surface of a current collector for positive electrodes .
  • the positive electrode mixture may contain various additives in addition to the conductor and the binder.
  • Preferred as the above-mentioned positive electrode active substance are metallic Li, Li x CoO 2 , Li x NiO 2 , Li x MnO 2 , Li x Co y Nii-y ⁇ 2, Li x Co y Ji-y0 z , Li x Nii- y J y O z , Li x Mn 2 O 4 , Li x Mn 2 .
  • y J y ⁇ 4 lithium-free oxides such as MnO 2 , V q 0 h and Cr g 0 h (g and h each being an integer of 1 or more) .
  • One or two or more species of them may be used.
  • the above-mentioned “J” represents at least one element selected from the group consisting of Na, Mg, Sc, Y, Mn, Fe, Co, Ni, Cu, Zn, Al, Cr, Pb, Sb and B.
  • the "x" varies as a result of charge or discharge of the battery.
  • the following compounds may be used as the positive electrode active substance: transition metal chalcogenides; vanadium oxides or niobium oxides, which may contain lithium; conjugated polymer-based organic conductive substances; and Chevrel phase compounds.
  • the positive active substance particles preferably have an average particle diameter of 1 to 30 ⁇ m.
  • the above-mentioned conductive agent for positive electrodes is an electron-conductive material not causing any chemical change at charge and discharge potentials for the positive electrode active substance used.
  • Preferred examples thereof include the same materials as in the above-mentioned conductive agent for negative electrodes; metals such as aluminum and silver, in powder form; conductive whiskers such as zinc oxide and potassium titanate; and conductive metal oxides such as titanium oxide.
  • metals such as aluminum and silver, in powder form
  • conductive whiskers such as zinc oxide and potassium titanate
  • conductive metal oxides such as titanium oxide.
  • One or two or more species of them may be used. Among these, artificial graphite, acetylene black and nickel in powder form are more preferred.
  • the use amount of the conductive agent for positive electrodes is preferably 1 to 50 parts by weight, and more preferably 1 to 30 parts by weight relative to 100 parts by weight of the positive electrode active substance.
  • the use amount is preferably 2 to 15 parts by weight relative to 100 parts by weight of the positive electrode active substance.
  • the above-mentioned binder for positive electrodes may be either a thermoplastic resin or a thermosetting resin. Preferred examples thereof include: those mentioned above in the binder for negative electrodes, other than styrene-butadiene rubbers; and tetrafluoroethylene-hexafluoroethylene copolymers. One or two or more species of them may be used. Among them, polyvinylidene fluoride and polytetrafluoroethylene are more preferred.
  • the above-mentioned current collector for positive electrodes is an electron conductor not causing any chemical change at charge and discharge potentials for the positive electrode active substance used.
  • Preferred examples thereof include stainless steel, aluminum, titanium, carbon, conductive resins, and aluminum or stainless steel having a surface on which carbon, nickel, and the like is adhered or coated.
  • One or two or more species of them may be used.
  • aluminum and aluminum-containing alloys are preferred.
  • the surface of these current collectors for positive electrodes may be oxidized and then used.
  • it is preferable that the surface of the current collector is provided with projections and depressions.
  • the current collector for positive electrodes has the same form and thickness as mentioned above in the current collector for negative electrodes.
  • the above-mentioned separators each is preferably made of a microporous insulating thin membrane showing a high ion permeability and a predetermined mechanical strength if an electrolytic solution is used as the ionic conductor. It is also preferable that the separators have a function of closing the pores at temperatures exceeding a certain temperature and thereby increasing the resistance .
  • the separator preferably has a pore diameter within a range such that it is impermeable to the positive electrode active substance, the negative electrode active substance, the binders and the conductive agents separated from the electrodes .
  • the separator preferably has a pore diameter of 0.01 to 1 urn.
  • the separator preferably has a thickness of 10 to 300 ⁇ m.
  • the void ratio is preferably 30 to 80%.
  • the separator surface is preferably modified in advance by corona discharge treatment, plasma discharge treatment, or wet treatment using a surfactant so that the hydrophobicity may be reduced.
  • Such treatment can improve the wettability of the separator surface and the pore inside, which makes it possible to prevent, to the utmost, the internal resistance of the battery from increasing.
  • an electrolytic solution-carrying polymer material gel may be contained in the positive electrode mixture or the negative electrode mixture, or a porous separator made of an electrolytic solution-carrying polymer material may be integratedwith the positive electrode or the negative electrode.
  • the above-mentioned polymer material is a material capable of holding the electrolytic solution and preferably is a vinylidene fluoride-hexafluoropropylene copolymer, for instance.
  • the above-mentioned lithium secondary battery has a coin form, button form, sheet form, layer-built form, cylindrical form, flat form, rectangular form, large form for use in an electric vehicle, and the like.
  • An electrolytic condenser is constituted of the following fundamental constituent elements : a condenser element including an anode foil, a cathode foil, an electrolytic paper sheet sandwiched between the anode foil and cathode foil and serving as a separator, and lead wires; an ionic conductor containing an electrolyte containing the above-mentioned ionic compound and/or the above-mentioned ionic composition; an exterior case of a cylinder shape with a bottom; and a sealing body for sealing the exterior case.
  • Fig. 2 (a) is a perspective view showing one embodiment of such a condenser element.
  • the electrolytic condenser of the present invention is obtained by: impregnating a condenser element with an electrolytic solution containing the above-mentioned ionic composition, which serves as an ionic conductor; accommodating the condenser element into an exterior case of a cylinder shape with a bottom; packaging a sealing body in an opening part of the exterior case and, at the same time, subjecting an end part of the exterior case to embossing procession; and thereby sealing the exterior case.
  • Preferred examples of such an electrolytic condenser include an aluminum electrolytic condenser, a tantalate electrolytic condenser, and a niobium electrolytic condenser.
  • FIG. 2 (b) is a cross-sectional view schematically showing one embodiment of such an aluminum electrolytic condenser.
  • a thin oxide (aluminum oxide) film to serve as a dielectric is formed, by electrolytic anodic oxidation, on the aluminum foil surface roughened by finely provided with projections and depressions by electrolytic etching.
  • an anode foil obtained by: chemically or electrochemically etching an aluminum foil having a purity of 99% or more in an acidic solution to perform plane extending treatment; performing formation treatment in an aqueous solution of ammonium borate, ammonium phosphate, ammonium adipate or the like; and forming an anode oxidized film layer on the surface.
  • the following aluminum foil can be used.
  • the aluminum foil is prepared by forming, on a part or all of the foil surface, a film made of one or more species of metal nitride selected from titanium nitride, zirconiumnitride, tantalumnitride andniobiumnitride, and/or, one or more species of metal selected from titanium, zirconium, tantalum and niobium.
  • the above-mentioned film can be formed by a deposition method, a plating method, a coating method and the like, for example.
  • the whole surface of the cathode foil may be covered.
  • a part of the cathode foil, for example, only one side of the cathode foil may be covered with a metal nitride or a metal.
  • Each of the above-mentioned lead wires is preferably constituted of a connecting part making contact with the anode foil and the cathode, foil; a round bar part; and an external connecting part.
  • Such lead wires are electrically connected to the anode foil and the cathode foil by means of such as a stitch and ultrasound welding, at the connecting parts, respectively.
  • the connecting part and the round bar part in the lead wire are preferably made of high purity aluminum.
  • the external connecting part is preferably made of a copper-plated iron steel wire which has been subjected to solder plating.
  • an aluminum oxide layer formed by anode oxidizing treatment with an aqueous solution of ammonium borate, an aqueous solution of ammonium phosphate, or an aqueous solution of ammonium adipate may be formed on a part or all of the surface of the round bar part and the connecting part with the cathode foil.
  • An insulating layer such as a ceramic coating layer made of Al 2 O 3 , SiO 2 and ZrO 2 or the like may be also formed on a part or all of the surface of the round bar part and the connecting part with the cathode foil .
  • the exterior case is preferably made of aluminum.
  • the sealing body is preferably provided with through holes from which the lead wires lead out, and made of an elastic rubber such as butyl rubber.
  • a rubber elastic body produced by the followingprocedures maybe used as suchbutyl rubber, for example .
  • the rubber elastic body is produced by: adding a reinforcing agent (carbon black or the like) , a bulking agent (clay, talc, calcium carbonate or the like) , a procession assistance (stearic acid, zinc oxide or the like) , a vulcanizing agent or the like to crude rubber made of an isobutylene-isoprene copolymer; kneading the mixture; and rolling and molding the resulting mixture .
  • a reinforcing agent carbon black or the like
  • a bulking agent clay, talc, calcium carbonate or the like
  • a procession assistance stearic acid, zinc oxide or the like
  • a vulcanizing agent or the like to crude rubber made of an isobutylene
  • vulcanizing agent examples include alkylphenol formalin resins; peroxides (dicumyl peroxide, 1, 1-di- (t-butylperoxy) -3, 3, 5- trimethylcyclohexane, 2, 5-dimethyl-2, 5-di- (t-butylperoxy) hexane or the like); quinoides (p-quinonedioxime, p, p' -dibenzoylquinonedioxime or the like) ; and sulfur. It is more preferable that the surface of the sealing body is coated with a resin such as teflon (registered trademark), or a plate of bakelite or the like is applied thereto, and thereby permeability of solvent steam is reduced.
  • a resin such as teflon (registered trademark)
  • a plate of bakelite or the like is applied thereto, and thereby permeability of solvent steam is reduced.
  • paper such as manila paper and kraft paper is usually used, and a non-woven fabric of a glass fiber, polypropylene / polyethylene or the like may be used.
  • the above-mentioned electrolytic condenser may be of a hermetic sealing structure, or of a structure in which the condenser is sealed in a resin case (described, for example, in Japan Kokai Publication No. Hei-08-148384) . In the case of an aluminum electrolytic condenser having a rubber sealing structure, gas is permeated through the rubber to some extent.
  • An electric double layer capacitor is constituted of the following fundamental constituent elements: a negative electrode, a positive electrode, and an ionic conductor containing an electrolyte containing the above-mentioned ionic compound and/or the above-mentioned ionic composition.
  • an electrolytic solution which is the ionic conductor, is contained in an electrode element composed of the positive electrode and the negative electrode opposed to each other.
  • Fig. 3 shows a sectional view schematically showing one embodiment of such an electric double layer capacitor and an enlargement view showing the electrode surface.
  • Each of the above-mentioned positive electrode and the above-mentioned negative electrode is a polarizable electrode.
  • Each of the electrodes is constituted of: active carbon serving as an electrode active substance, such as active carbon fibers, a molding of active carbon particles, or active carbon particles; a conductive agent; and a binder substance, and is preferably used in such a molded form as a thin coat film, a sheet or a plate.
  • active carbon serving as an electrode active substance, such as active carbon fibers, a molding of active carbon particles, or active carbon particles
  • a conductive agent such as a molded form as a thin coat film, a sheet or a plate.
  • the above-mentioned active carbon preferably has an average pore diameter of 2.5 nm or less. This average pore diameter of the active carbon is preferablymeasuredby a nitrogen adsorption BET method.
  • the specific surface area of the active carbon depends on the electrostatic capacity of the carbonaceous species per unit area (F/m 2 ) or on decrease in bulk density due to increase in specific surface area.
  • the specific surface area determined by the nitrogen adsorption BET method is preferably 500 to 2500 m 2 /g, and more preferably 1000 to 2000
  • the above-mentioned active carbon is preferably produced by the following activation method.
  • the activation method includes carbonizing the following raw material and then activating the carbonated substance.
  • the raw materials include : plant materials such as wood, sawdust, coconut shells or pulping waste liquor; fossil fuel materials, such as coal, heavy petroleum oil, or pyrolyzate derived therefrom, e.g. coal pitch, petroleum pitch, petroleum coke, carbon aerogel, mesophase carbon, tar pitch fiber; synthetic polymer, phenol resin, furan resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyimide resin, polyamide resin, ion exchange resin, liquid crystal polymers; a plastic waste; and a waste tire .
  • the above-mentioned activation method includes the following methods (1) and (2) : (1) gas activation method in which the carbonized raw material is brought into contact with steam, carbon oxide gas, oxygen, or other oxidizing gas and thereby reactedwith each other at high temperatures; and (2) the chemical activation method in which the carbonized raw material is homogeneously impregnated with zinc chloride, phosphoric acid, sodium phosphate, calcium chloride, potassium sulfide, potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, sodium sulfate, potassium sulfate, calcium carbonate, boric acid, or nitric acid, and then the mixture is heated in an inert gas atmosphere to give active carbon as a result of dehydration and oxidation reactions in the presence of a chemical. Either of the methods may be used.
  • the active carbon obtained by the above-mentioned activation method is thermally treated in an inert gas atmosphere, such as nitrogen, argon, helium or xenon at preferably 500 to 2500°C and more preferably 700 to 1500 0 C, thereby to eliminate unnecessary surface functional groups and/or develop the crystallinity of the carbon for increasing the electronic conductivity.
  • the active carbon may be in a crushed, granulated, granular, fibrous, felt-like, woven or sheet form, for instance. If the active carbon is in a granular shape, it preferably has an average grain diameter of 30 um or less from the viewpoint of improvement in the electrode bulk density and reduction in the internal resistance.
  • Carbonaceous materials having such a high specific surface area as mentioned above may be used as the electrode active substance, in addition to the active carbons .
  • carbon nanotubes or diamond produced by plasma CVD also may be used.
  • Preferred examples of the above-mentioned conductive agent include carbon black such as acetylene black and Ketjen black, natural graphite, thermally expansible graphite, carbon fibers, ruthenium oxide, titanium oxide, aluminum, nickel or like metal fibers. One or two or more species of them may be used. Among them, acetylene black and Ketjen black are more preferred since they can effectively improve the conductivity in small amounts.
  • the mixing amount of the conductive agent varies depending on the bulk density of the active carbon and the like, but preferably is 5 to 50% by weight, andmore preferably 10 to 30% by weight, relative to 100% by weight of the active carbon.
  • Preferred examples of the above-mentioned binder substance include polytetrafluoroethylene, polyvinylidene fluoride, carboxymethylcellulose, fluoroolefin copolymer crosslinked polymers, polyvinyl alcohol, polyacrylic acid, polyimides, petroleuinpitch, coalpitch, and phenol resins .
  • One or two or more species of them may be used.
  • the mixing amount of the binder substance varies depending on the active carbon species and the form thereof, but is preferably 0.5 to 30% by weight, and more preferably 2 to 30% by weight, relative to 100% by weight of the active carbon.
  • Each of the above-mentioned positive electrode and the above-mentioned negative electrode is preferably formed by the following methods (1) to (3) : (1) a method in which polytetrafluoroethylene is added and mixed with a mixture of the active carbon and acetylene black and the resulting mixture is molded by pressing; (2) a method in which the active carbon and the binder substance such as pitch, tar, and phenolic resin and the mixture is molded, and the molding was thermally treated in an inert atmosphere to give a sintered body; and (3) a method in which the active carbon and the binder substance, or only the active carbon, is sintered to form an electrode .
  • the cloth as it is may be used as an electrode without using any binder substances.
  • the polarizable electrodes are preferably prevented from contacting or short-circuiting with each other by inserting a separator between the polarizable electrodes or by opposing the polarizable electrodes with a space between them using a holding means, for instance.
  • a separator between the polarizable electrodes or by opposing the polarizable electrodes with a space between them using a holding means, for instance.
  • Suitable separator materials are paper, polypropylene, polyethylene and glass fibers, and the like.
  • the form of the above-mentioned electric double layer capacitor includes a coin type, wound type, rectangular type, aluminum laminate type and the like. Any form may be employed.
  • the electrochemical devices such as the lithium secondary battery, the electrolytic condenser, and the electric double layer capacitor, each prepared using the above-mentioned ionic compound and/or the above-mentioned ionic composition, are preferably used in various applications such as portable information terminals, portable electronic apparatuses, small-sized household electric power storages, motorcycles, electric vehicles, and hybrid electric vehicles.
  • lithium dicyanotriazolate is used as the above-mentioned ionic compound. It is preferable that the above-mentioned lithium dicyanotriazolate is contained in an electrolyte for lithium batteries.
  • the combinations of an electrolyte, a separator, a positive electrode, a negative electrode, and the like may be appropriately determined depending on functions or configurations of lithium batteries to be used, such as primary batteries, lithium ion secondary batteries and lithium polymer secondary batteries.
  • an electrolyte having ionic conductivity suitable for primary batteries, lithium ion secondary batteries, and lithium polymer secondary batteries can be produced by adding LiDCTA to an organic solvent and/or a polyether polymer or an acrylic polymer.
  • separators may be used if necessary, except for the cases where the polymer-containing electrolyte provides sufficient film strength.
  • Examples of the base material of the above-mentioned polymer electrolyte include polyether copolymers such as polyethylene oxide andpolypropylene oxide . Polyethylene oxide is preferable.
  • the proportion of LiDCTA is preferably 10 to 35% by weight in the above-mentioned polymer electrolyte. If the proportion is less than 10% by weight, a sufficient conductivity may not be obtained. If the proportion is more than 25% by weight, the LiDCTA may be insufficiently dissolved. The proportion is preferably 15 to 30% by weight.
  • the above-mentioned polymer electrolyte preferably contains no solvents.
  • the electrolyte may contain 1 to 99% by weight of a solvent in 100% by weight of the electrolyte material, if the polymer electrolyte maintains sufficient film strength. If the solvent is less than 1% by weight, the ionic conductivity is insufficiently improved. If the solvent is more than 99% by weight, the stability may be insufficiently improved due to volatilization of the solvent.
  • the lower limit is preferably 1.5% by weight, and more preferably 20% by weight, and still more preferably 50% by weight.
  • the upper limit is preferably 85% by weight, and more preferably 75% by weight, and still more preferably 65% by weight. It is preferable that the solvent accounts for 50 to 85% by weight in the electrolyte material .
  • the above-mentioned solvent is a solvent capable of improving the ionic conductivity.
  • Organic solvents are preferable, for example.
  • the organic solvents mentioned above are preferably used as the above-mentioned organic solvent. Among them, carbonic acid esters, aliphatic esters, and ethers are more preferable, and carbonates are still more preferable.
  • the above-mentioned solvent may contain an ionic liquid.
  • the ionic liquid is a compound composed of a cation and an anion. One or two or more species of the ionic liquid may be used.
  • the above-mentioned ionic liquid is preferably a liquid having fluidity and a certain specified volume at 40°C. Specifically, it is preferable the ionic liquid is a liquid having a viscosity of 500 mPa-s or less at 40 0 C.
  • the viscosity is more preferably 200 mPa-s or less, and still more preferably 100 mPa-s.
  • an ionic liquid include l-ethyl-3-methylimidazolium trifluoromethane sulfonimide, l-ethyl-3-methylimidazolium dicyanoamide, l-ethyl-3-methylimidazolium tricyanomethide, diethyl dimethoxy trifluoromethane sulfonimide, diethyl dimethoxy dicyanoamide, diethyl dimethoxy tricyanomethide, 1-methyl-l-butyl trifluoromethane sulfonimide, 1-methyl-1-butyldicyanoamide, and 1-methyl-l-butyltricyanomethide .
  • the above-mentioned electrolyte containing the lithium dicyanotriazolate is preferably used in a lithium battery.
  • the above-mentioned lithium battery is preferably constituted of the following fundamental constituent elements: apositive electrode, a negative electrode, separators occurring between the positive and negative electrodes, and the above-mentioned electrolyte containing lithium dicyanotriazolate.
  • Preferred as such a lithium secondary battery is a nonaqueous electrolyte lithium secondary battery, which is other than an aqueous electrolyte lithium secondary battery.
  • Metallic lithium is preferably used as the above-mentioned negative electrode in lithium primary batteries and lithium polymer secondary batteries.
  • the above-mentioned negative electrode is preferably produced by applying a negative electrode mixture containing a negative electrode active substance, a conductive agent for negative electrodes, a binder for negative electrodes, and the like to the surface of a current collector for negative electrodes.
  • the above-mentioned lithium dicyanotriazolate has a high ionic conductivity and causes no corrosion to the electrodes and the like.
  • such lithium dicyanotriazolate is stable over time. Therefore, an ionic composition containing such an ionic compound is excellent in charge and discharge properties, and therefore permits practical use of electrochemical devices such as lithium batteries having long-term reliability.
  • electrochemical devices such as lithium secondary batteries, prepared using the above-mentioned polymer electrolyte containing lithium dicyanotriazolate, can be preferably used in various applications such as portable information terminals and portable electronic apparatuses.
  • reaction solution was subjected to extraction step using diethyl ether and ion exchange water to obtain a brown solid.
  • This obtained solid was sublimed at 80°C and at 30 Pa to obtain white 4, 5-dicyanotriazole (hereinafter, described as HDCTA) 16O g.
  • theHDCTA119g (l.Omol) was dissolved in ion exchange water 500 g, and thereto a 30% by weight aqueous solution of sodium hydroxide 40 g was added under cooling. Thereby, an aqueous solution of sodium dicyanotriazolate was obtained.
  • This cake-like substance was dispersed into ion exchange water and then subjected to suction filtration. This operation was repeated three times to obtain cake-like silver dicyanotriazolate (hereinafter, described as AgDCTA) .
  • This AgDCTA has a solids content of 85%.
  • EMImDCTA l-ethyl-3-methylimidazolium dicyanotriazolate
  • This l-ethyl-3-methylimidazolium dicyanotriazolate had a moisture content of 50 ppm, an excess acid amount of 0.05 * 10 '3 mol/g, a content of an amidated product of 1.4%.
  • Fig. 4 shows 1 H-NMR of the obtained EMImDCTA.
  • Fig. 5 shows 13 C-NMR of the obtained EMImDCTA. The measurements were performed under the following conditions, respectively.
  • This EMImDCTA was a buff yellow solid and had a thermal decomposition temperature in nitrogen of 218°C.
  • a mixture of this EMImDCTA with propylene carbonate (hereinafter, abbreviated to PC) 2 mol/kg had an ionic conductivity at 25°C of 3.0 * 10 "2 S/cm.
  • the number of data points 32768 Measurement time 1 minute (Measurement conditions in Fig. 5)
  • Pulse 44.6 degree pulse Incorporation time: 1.498 seconds
  • the HDCTA 35.7 g (0.3 mol) obtained in the step 2 in Example 1 was dissolved in methanol 200 g. Thereto, triethylamine 30.3 g (0.3 mol) was added dropwise over 1 hour while the system was maintained at 30°C or less. Then, from the obtained solution, volatile contents were removed using a rotating evaporator at 50 0 C and at 10 to 200 mmHg.
  • TEADCTA triethylammonium dicyanotriazolate
  • This triethylammonium dicyanotriazolate had a moisture content of 45 ppm, an excess acid amount of 0.06 * 10 "3 mol/g, and an amidated product content of 1.2%.
  • Fig. 6 shows 1 H-NMR of the obtained TEADCTA.
  • Fig. 7 shows 13 C-NMR of the obtained TEADCTA. The measurements were performed under the following conditions, respectively.
  • This TEADCTA was a buff yellow solid and had a thermal decomposition temperature in nitrogen of 93°C.
  • a mixture of this TEADCTAwith PC 2 mol/kg had an ionic conductivity at 25 0 C of 1.8 * 10 "2 S/cm.
  • Pulse 45.0 degree pulse
  • the HDCTA 35.7 g ( 0.3 mol ) obtained in the step 2 in Example 1 was dissolved in methanol 200 g. Then, this solution was added into a dispersion Iiquidpreparedby dispersing lithiumcarbonate 11.1 g (0.15 mol) into methanol 300 g over 1 hour. From this obtained solution, volatile contents were removed at 50 0 C and at 10 to 200 mitiHg using a rotating evaporator . Then, the obtained substance was dried at 80 0 C under reduced pressure for 3 days to obtain lithium dicyanotriazolate (hereinafter, abbreviated to LiDCTA) . ALiDCTA-PC solution lmol/L was tried to be prepared. However, the LiDCTA was difficult to dissolve in PC, and a great amount of the LiDCTA was not dissolved and remained, which made it impossible to measure the ionic conductivity. Production Example 1
  • the obtained filtrate was dried and hardened with a rotating evaporator by removing moisture therefrom.
  • Diisopropyl ether 400g was added to the obtained solid to extract dicyanotriazole therefrom. Then, water 400 g was added to the dicyanopropyl ether phase and thereby impurities causing coloring were washed. The solvent was removed from the diisopropyl ether solution of the dicyanotriazolewith a rotating evaporator. Thereby, HDCTA having a Hazen of 200 was obtained.
  • the HDCTA obtained in Production Example 1 was sublimed at one time under reduced pressure for 50 minutes at 125°C and at 30 Pa. Thereby, 100 g of purified HDCTA having a Hazen of 30 was obtained.
  • HDCTA was synthesized according to descriptions in "Lithium Dicyanotriazolate as a Lithium Salt for Poly (ethylene oxide) Based Polymer Electolytes, Electrochemical and Solid-State Letters" 2003, vol.6, No.4, and p. A71 to A73, Egashira and four others) .
  • Diaminomaleonitrile 21.6 g (200mol) , 35% hydrochloric acid 20.9 g (HCL 200 mmol) , and water 236 g were weighed and charged into a 500 mL-separable flask, and themixture was stirred with a paddle blade. The flask was in a dry ice-acetone freezing mixture and thereby the internal pressure was kept at O 0 C.
  • the obtained LiDCTA 100 g and toluene 1000 g were charged into a 2L-separable flask, themixture was subjected to azeotropy dehydration at 50 0 C for 20 minutes and at 130°C for 100 minutes while performing reflux of the toluene.
  • the resulting substance was subjected to suction filtration with a 0.2 ⁇ m PTFE filter and the obtained solid was dried at 140 0 C under reduced pressure.
  • This LiDCTA had a moisture content of 860 ppm, an excess acid amount of 0.05 x 10 "3 mol/g, a Hazen of 5, and an amidated product concentration (amidated product content) of 0.20%.
  • Example 6-1 LiDCTA was obtained in the same manner as in Example 5-1, except that the azeotropy dehydrationwas performedby distilling the toluene without reflux of the toluene.
  • This LiDCTA had a moisture content of 510 ppm, an excess acid amount of 0.05 * 10 "3 mol/g, a Hazen of 7 , and an amidated product concentration of 0.19%.
  • Example 5-1 Into dehydrated acetonitrile (product of KANTO CHEMICAL CO., INC., moisture of 25 ppm) 180g, 20 g of the LiDCTA obtained in Example 5-1 was dissolved. The mixture was dried with a molecular sieve 2 g (UNION SHOWA K. K., Li-A) and then dried substance was subjected to suction filtration with a 0.5 um hydrophilic PTFE filter. The obtained filtrate was dried and hardened with a rotating evaporator and then further dried under reduced pressure. The obtained LiDCTA had a moisture content of 170 ppm, an excess acid amount of 0.05 mmol/g, a Hazen of 160, and an amidated product concentration of 0.14%.
  • acetonitrile product of KANTO CHEMICAL CO., INC., moisture of 25 ppm
  • LiDCTA was obtained in the same manner as in Example 5-1, except that lithium carbonate was added to an aqueous solution containing 10 g of the HDCTA obtained in Production Example 2 until the solution showed a pH of 5.
  • This LiDCTA had a moisture content of 450 ppm, an excess acid amount of 0.15 * 10 ⁇ 3 mol/g, a Hazen of 100, and an amidated product concentration of 0.14%.
  • LiDCTA was obtained in the same manner as in Example 5-1, except that lithium carbonate was added to an aqueous solution containing 10 g of the HDCTA obtained in Production Example 2 until the solution showed a pH of 9.
  • This LiDCTA had a moisture content of 450 ppm, an excess acid amount of 0.15 * 10 ⁇ 3 mol/g, a Hazen of 150, and an amidated product concentration of 0.35%.
  • This LiDCTA had a moisture content of 920 ppm, an excess acid amount of 0.20 mmol/g, a Hazen of 5, and an amidated product concentration of 0.18%.
  • LiDCTA was obtained in the same manner as in Example 5-1, except that the toluene was subjected to azeotropic dehydration at 50 0 C for 20 minutes and at 130°C for 40 minutes.
  • This LiDCTA had a moisture content of 1520 ppm, an excess acid amount of 0.05 x 10 "3 mol/g, a Hazen of 7, and an amidated product concentration of 0.19%.
  • LiDCTA was obtained in the same manner as in Example 5-1, except that lithium carbonate was added to an aqueous solution containing 10 g of the HDCTA obtained in Production Example 2 until the solution showed a pH of 10.
  • This LiDCTA had a moisture content of 450 ppm, an excess acid amount of 0.2 * 10 "3 mol/g, a Hazen of 140, and an amidated product concentration of 0.18%.
  • LiDCTA was obtained in the same manner as in Example 5-1, except that the toluene was subjected to azeotropic dehydration at 50 0 C for 20 minutes and at 130 0 C for 70 minutes.
  • This LiDCTA had a moisture content of 1080 ppm, an excess acid amount of 0.05 x 10 3 ItIoIZg, a Hazen of 6, and an amidated product concentration of 0.20%.
  • Reference Example (A) 6-1 Into acetonitrile 100 g, 1Og (84mi ⁇ ol) of the HDCA obtained in Comparative Production Example 1 was dissolved. Thereto, lithium carbonate 3.5 g (47 mmol) was added and reaction was performed for 2 hours at room temperatures under stirring. The reaction liquid was subjected to suction filtration with a 0.5 ⁇ mhydrophilic PTFE filter to remove unreacted lithium carbonate therefrom. The obtained filtrate had a pH of 7. This filtrate was dried and hardened with a rotating evaporator to obtained LiDCTA. This obtained LiDCTA 1Og and toluene 100 g were charged into a 200 mL-separable flask.
  • the mixture was subjected to azeotropy dehydration at 130 0 C for 120 minutes while performing reflux of the toluene. This was subjected to suction filtration with a 0.2 ⁇ m PTFE filter and the obtained solid was dried at 140 0 C under reduced pressure.
  • This LiDCTA had a moisture content of 600 ppm, an excess acid amount of 0.21 mmol/g, a Hazen of 6, and an amidated product concentration of 0.21%.
  • LiDCTA was obtained in the same manner as in Example 5-1, except that 10 g of the HDCTA obtained in Production Example
  • This LiDCTA had a moisture content of 700 ppm, an excess acid amount of 0.05 x 10 ⁇ 3 mol/g, and a Hazen of 240.
  • Reference Example (B) 2-1 LiDCTA was obtained in the same manner as in Example 5-1, except that the azeotropy of the toluene was performed at 150 0 C for 120 minutes .
  • This LiDCTA had a moisture content of 980 ppm, an excess acid amount of 0.05 x 10 "3 mol/g, a Hazen of 5, and an amidated product concentration of 1.05%.
  • LiDCTA was obtained in the same manner as in Example 5-1, except that the azeotropy of the toluene was performed at 170°C for 120 minutes .
  • This LiDCTA had a moisture content of 920 ppm, an excess acid amount of 0.06 x 10 "3 mol/g, a Hazen of 4, and an amidated product concentration of 3.01%.
  • Example 5-1 The LiDCTA described in Example 5-1 was subjected to the evaluation test of reactivity with the electrode. No change was observed on the Li-foil surface.
  • Example 6-1 The LiDCTA described in Example 6-1 was subjected to the evaluation test of reactivity with the electrode. No change was observed on the Li-foil surface.
  • Example 7-1 The LiDCTA described in Example 7-1 was subjected to the evaluation test of reactivity with the electrode. No change was observed on the Li-foil surface.
  • Example 8-1 The LiDCTA described in Example 8-1 was subjected to the evaluation test of reactivity with the electrode. No change was observed on the Li-foil surface.
  • Example 9-1 The LiDCTA described in Example 9-1 was subjected to the evaluation test of reactivity with the electrode. " No change was observed on the Li-foil surface.
  • the LiDCTA described in Reference Example (A) 2-1 was subjected to the evaluation test of reactivity with the electrode , The portion on the Li-foil surface where the LiDCTA solution was applied was turned black.
  • Reference Example (A) 3-2 The LiDCTA described in Reference Example (A) 3-1 was subjected to the evaluation test of reactivity with the electrode . The portion on the Li-foil surface where the LiDCTA solution was applied was turned black.
  • the LiDCTA described in Reference Example (A) 4-1 was subjected to the evaluation test of reactivitywith the electrode .
  • the LiDCTA described in Reference Example (A) 5-1 was subjected to the evaluation test of reactivity with the electrode .
  • the portion on the Li-foil surface where the LiDCTA solution was applied was turned black.
  • the LiDCTA described in Reference Example (A) 6-1 was subjected to the evaluation test of reactivity with the electrode.
  • the portion on the Li-foil surface where the LiDCTA solution was applied was turned black.
  • the LiDCTA described in Reference Example (B) 1-1 was subjected to the evaluation test of reactivity with the electrode, No change was observed on the Li-foil surface.
  • the LiDCTA described in Reference Example (B) 2-1 was subjected to the evaluation test of reactivity with the electrode . No change was observed on the Li-foil surface.
  • LiDCTA, V 2 Os, acetyleneblack, andPEO polyethylene oxide
  • LiDCTA, P(E0/AGE) (poly (ethylene oxide-allyl glycidyl ether) copolymer) , and Irgacure 651 (2, 2-dimethoxy-l, 2-diphenylethane-l-one) were dissolved in acetonitrile. This mixture was sufficiently stirred with a magnetic stirrer to be homogeneous. Therefrom, insoluble contents were removed with a filter and degassing was performed under reduced pressure. Thus-prepared solution was applied on a copper foil to have a thickness of 250 ⁇ m and dried at 60°C for 30 minutes under reduced pressure. This foil was irradiated with ultraviolet and thereby a polymer was cross-linked. This obtained filmwas further driedat 60 0 C for one night under reduced pressure. As a result, a SPE was prepared.
  • the cathode, the SPE, each prepared by the above-mentioned methods, and a lithium foil were circularly pierced using punches having a diameter of 12 mm, 16 mm, and 14 mm.
  • the lithium foil, the SPE, and the cathode were stuck together in this order. This was sandwiched with two circular stainless plates each with a diameter of 16 mm. Further, a spring spacer was placed on the positive electrode side and then this was put into a CR2032 type batterycan. Thisbattery canwas caulkedwitha caulkingmachine to prepare a coin battery.
  • Example 5-1 Using the LiDCTA described in Example 5-1, three coin batteries were prepared by the above-mentioned method. The three coin batteries were subjected to the charge and discharge test . The coin batteries showed excellent charge and discharge properties.
  • Reference Example (B) 1-3 Using the LiDCTA described in Reference Example (B) 1-1, three coinbatteries werepreparedby the above-mentionedmethod. The three coin batteries were subjected to the charge and discharge test . The results showed that the three coinbatteries could not be used as a secondary battery because the capacitor was remarkably reduced and the resistance between the electrodes after the test was also remarkably increased.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Inorganic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • General Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Dispersion Chemistry (AREA)
  • Secondary Cells (AREA)

Abstract

To provide: an ionic compound which can exhibit excellent basic performances such as electrochemical stability and can be preferably used in various applications; a composition containing such an ionic compound; and a battery prepared using such an ionic compound and/or an ionic composition. The above-mentioned ionic compound is an ionic compound having: a moisture content of 1000 ppm or less; and an excess acid amount or an excess base amount of less than 0.2 x 10-3 mol/g, wherein the ionic compound comprises dicyanotriazolate anion and a specific cation.

Description

DESCRIPTION
IONIC COMPOUND
TECHNICAL FIELD
The present invention relates to an ionic compound. More specifically, thepresent invention relates to: an ionic compound which is preferable as a material for ionic conductors constituting electrochemical devices; an ionic composition containing such an ionic compound; and a battery prepared using such an ionic compound and/or such an ionic composition.
BACKGROUND ART Ionic compounds are composed of a cation and an anion and have been widely used in various applications . Among such ionic compounds, substances having ionic conductivity are preferably used, as an electrolyte, in constituent materials of ionic conductors which are essential in various ion conductive batteries. The constituent materials of ionic conductors can function as an electrolyte and/or a solvent in electrolytic solutions constituting the ionic conductors, or can function as a solid electrolyte. Examples of the applications include electrochemical devices such as: batteries having charge and discharge mechanisms such as primary batteries, lithium (ion) secondary batteries, and fuel batteries; electrolytic condensers; electric double layer capacitors; and solar cells and electrochromic display devices. In these devices, each battery is generally constituted of a pair of electrodes and an ionic conductor occurring therebetween. Currently used as such ionic conductors are electrolytic solutions preparedby dissolving an electrolyte, such as lithium perchlorate, LiPF6, LiBF4, tetraethylammonium fluoroborate or tetramethylammonium phthalate, in an organic solvent such as γ-butyrolactone, N, N-dimethylformamide, propylene carbonate or tetrahydrofuran. In such ionic conductors, the electrolyte, when dissolved, dissociates into a cation and an anion to cause ionic conduction through the electrolytic solution. Solid electrolytes which can cause ionic conduction with the solid state have been used as an ionic conductor. Fig. 1 shows a cross sectional view schematically showing one embodiment of a conventional lithium (ion) secondarybattery . Such a lithium (ion) secondary battery has a positive electrode and a negative electrode each formed of an active substance, and an electrolytic solution constituted of an organic solvent and a lithium salt such as LiPF6 dissolved as a solute in the solvent, forms an ionic conductor between the positive and negative electrodes. In this case, during charging, the reaction CβLi -> 6C + Li + e" occurs on the negative electrode, the electron (e~) generated on the negative electrode surface migrates through the electrolytic solution to the positive electrode surface in the manner of ionic conduction. On the positive electrode surface, the reaction CoO2 + Li + e~ → LiCoO2 occurs and an electric current flows from the negative electrode to the positive electrode. During discharging, reverse reactions as compared with those during charging occur, and an electric current runs from the positive electrode to the negative electrode .
However, such an electrolytic solution, which constitutes an electrochemical device, has needed to be improved in some respects: the organic solvent is readily volatile and has a low flash point; the liquid leak may readily occur, resulting in lack in long-term reliability; and the electrolytic solution coagulates at low temperatures and therefore fails to show performances as an electrolytic solution. Thus, materials capable of improving these problems have been demanded.
Japanese Kohyo Publication No. 2000-508676 (pages 2 to 13, and 39 to 67) discloses an ionic compound containing at least one anionic part bonded to at least one cationic part M, wherein M is hydroxonium, nitrosonium, NO+, ammonium, NH4 +, a metal cation having a valency of m, an organic cation, or an organic metal cation; and the anion part has a five-membered ring structure or derived from tetraazapentalene. The Example discloses, as the anionic part, derivatives of triazole, imidazol, and cyclopentadiene . Japanese Kokai Publication No . 2004-331521 (pages 2 and 3) discloses an ionic liquid containing a
N-alkylimidazolium cation or an ammonium cation, and a tetrazole anion or a triazole anion. However, such ionic compounds have room for improvement in order to be preferably used in various applications 'such as materials constituting electrochemical devices and exhibit excellent basic performances.
Halogen-containing lithium salts such as LiClO4, LiN(SO2CFa)2, LiN(SO2C2Fs)2, LiSO3CF3, LiSO3C2F5, LiBF4, LiPF6, and LiAsF5 arementioned as generallyused compounds as an electrolyte (ionic conductor) for lithium batteries. However, such halogen-containing lithium salts have been insufficient in stability, safety, or conductivity needed as an electrolyte for lithium batteries. That is, if these lithium salts are used as an electrolyte for lithium batteries and the like, it is known that leakage of an electrolytic solution or deterioration thereof caused by the halogen is caused, and the solution may leak. Therefore, electrolytes with high safety have been desired. Ionic conductive materials having high conductivity that are anion salts having a five-membered ring have been investigated. CA2194127 (pages 89 and 99) discloses lithium dicyanotriazolate not containing halogen, as one example of this anion salt containing a five-membered ring. Further, Electrochemical and Solid-StateLetters, egashira, etal., 2003, Vol.6, No.4, andp. A71-A73, discloses lithiumdicyanotriazolate as a lithium salt of a polyethylene oxide-based polymer electrolytic solution. These documents disclose the following production method of lithium dicyanotriazolate (LiDCTA) .
First, diaminomaleonitrile (200 mmol) is added to an aqueous solution 250 mL adjusted to an acid solution with hydrochloric acid 200 mmol to prepare slurry. One equivalent amount of sodium nitrite is added to this slurry under stirring while the temperature is maintained at O0C to obtain a brown reaction mixture. This reaction mixture is filtered and subjected to extraction three times with ether. The extract is evaporated and then the ether is evaporatedby drying to obtain coarse dicyanotriazole (HDCTA) . Thus-obtained coarse HDCTA is sublimed two times at 80°C to obtain purified HDCTA. Then, this HDCTA is treated with a slightly excess amount of lithium carbonate to obtain a turbid solution. This solution is subjected to centrifugal separation. The obtained supernatant liquid is dried under reduced pressure to obtain LiDCTA.
However, this lithium dicyanotriazolate also has room for improvement in order to exhibit high charge and discharge properties needed as an electrolyte for lithium batteries for a more prolonged period.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above-mentioned state of the art. The present invention has an object to provide: an ionic compound which can exhibit excellent basic performances such as electrochemical stability and can be preferably used in various applications such as materials for electrochemical devices; a composition containing such an ionic compound; and a battery prepared using such an ionic compound and/or an ionic composition. The present inventors have made various investigations on ionic compounds. The inventors noted that triazolate anion having triazole as an anion skeleton. Triazolate is a unique anion having a ring structure, and triazolate has low acidity singly and therefore needs to be improved. The inventors found that if two cyano groups (-CN) are introduced as a substituent, into triazolate to form dicyanotriazolate anion, such dicyanotriazolate anion has increased electric adsorption due to the introduction of two cyano groups, and therefore can be stabilized. They have also found that if the ionic compound containing such anion contains a specific cation having a monovalent element or an organic group, such an ionic compound can be easily dissolved in a matrix (solvent and the like) as compared with inorganic salts, and that if such an ionic compound contains an alkali metal ion, such an ionic compound can exhibit excellent basic performances such as high ionic conductivity and high stability. The inventors also found that if a moisture content, and an excess acid amount or an excess base amount, or a content of an amidated product are specified in such an ionic compound, the ionic compound can prevent side reaction with an electrode or deterioration of an electrolyte while exhibiting excellent charge and discharge properties needed as an electrolyte for lithium batteries and the like, which permits practical use of electrochemical devices such as lithium batteries having prolonged reliability. The inventors also found that an ionic composition which contains an ionic compound satisfying a specific excess acid amount or excess base amount, and has a specific moisture content also permits practical use of electrochemical devices such as lithium batteries having prolonged reliability. As a result, the above-mentioned problems have been admirably solved. Further, the present inventors found that if such an ionic compound or ionic composition contains no fluorine atom, due to the absence of the fluorine atom, corrosivity on electrodes and the like can be suppressed, which permits stable function over time. The inventors also found that such an ionic compound and ionic composition can function as a liquid material constituting an electrolytic solution and can be preferably applied in various applications such as materials for electrochemical devices. Thereby, the present invention has been completed. That is, the present invention relates to an ionic compound having: a moisture content of 1000 ppm or less; and an excess acid amount or an excess base amount of less than 0.2 * 10"3 mol/g, wherein the ionic compound comprises a dicyanotriazolate anion and at least one cation selected from the group consisting of cations represented by the following formula (1) : Rs L ( 1 )
(in the formula, L representing at least one element selected from the group consisting of C, Si, N, P, S, and 0; R being the same or different and each representing a monovalent element or an organic group, and may be bonded together; and s being an integer of 3 to 5 and being a value determined by the valency of the element L) and alkali metal ions.
The present invention also relates to an ionic compound comprising a dicyanotriazolate anion, wherein the ionic compound contains 1.5% by weight or less of an amidated product of the dicyanotriazolate anion.
The present invention includes an ionic compound comprising a dicyanotriazolate anion and a cation represented by the above formula (1) .
The present invention also relates to an ionic composition comprising an ionic compound and having a moisture content of 1000 ppm or less, wherein the ionic compound has an excess acid amount or an excess base amount of less than 0.2 * 10"3 mol/g. The present invention also relates to a battery prepared using the ionic compound and/or the ionic composition.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig.1 shows a cross-sectional view schematically showing one embodiment of a lithium secondary battery.
Fig. 2 (a) is a perspective view showing one embodiment of an electrolytic condenser.
Fig. 2 (b) is a perspective view showing one embodiment of an aluminum electrolytic condenser.
Fig. 3 is a cross-sectional view schematically showing one embodiment of an electric double layer capacitor and an enlarged view of the electrode surface.
Fig. 4 is a 1H-NMR chart of EMImDCTA obtained in Example Fig . 5 is a 3C-NMR chart o f EMImDCTA obtained in Exampl e
1 .
Fig. 6 is a 1H-NMR chart of TEADCTA obtained in Example 2.
Fig. 7 is a 13C-NMR chart of TEADCTA obtained in Example
2.
Symbols in the drawings are as follows.
(A) : Discharge (B) : Charge
1: Negative electrode current collector (copper)
2: Negative electrode (active substance)
3 : Separator
4: Electrolyte (Electrolytic solution) (Li salts, such as LiPF) 5: Positive electrode (active substance)
6: Positive electrode current collector (aluminum)
7: External connecting part
8 : Round bar part
9: Lead wire 10: Electrolysis paper
11: Cathode foil
12: Anode foil
13: Aluminum foil
14: Dielectric (aluminium oxide) 15: Electrolytic papter
16: Anode foil
17: Electrolytic solution
18: Cathode foil
19: Activated carbon electrode 20: Electrolytic solution
21: Anion
22: Cation
DETAILED DESCRIPTION OF THE INVENTION The present invention is described in more detail below, -IONIC COMPOUND-
The ionic compound of the present invention contains a cation and an anion, and has: a moisture content of 1000 ppm or less; and an excess acid amount or an excess base -amount of less than 0.2 * 10"3 mol/g.
The above-mentionedmoisture content is amoisture content relative to a weight of solids of the ionic compound, and preferably 1000 ppm or less. The moisture content is more preferably 800 ppm or less, and still more preferably 500 ppm or less, and furthermore preferably 200 ppm or less.
The above-mentioned moisture content can be measured as follows . "Measurement of moisture content"
In a glove box or dry room controlled to atmosphere under a temperature of 200C and a dew point of -60°C or less, the ionic compound 0.2 g is dissolved in dehydrated methanol 1.8 g. This solution is measured for moisture content (A ppm) using the Karl Fischer method. Similarly, the dehydrated methanol used for preparing this solution is also measured for moisture content (Bppm) using theKarl Fischermethod. Then, themoisture content (C ppm) of the ionic compound is calculated from the following formula 1. C = (A x (1.8 + 0.2))-B x 1.8/0.2 (formula 1)
In the present description, if a state where the contents of the cation and the anion in the ionic compound are the same is defined as basis, a state where the content of the cation is smaller than that of the anion is defined as "state where the acids are excessive" and the degree is represented by "excess acid amount". Further, if the state where the contents of the cation and the anion are the same in the ionic compound is defined as a basis, a state where the content of the cation is larger than that of the anion is defined as "state where the bases are excessive" and the degree is representedby "excess base amount" .
The above-mentioned excess acid amount or the above-mentioned excess base amount of the ionic compound is preferably less than 0.2 * 10~3 mol/g, and more preferably 0.18 x 10"3 mol/g or less.
The above-mentioned excess acid amount or the above-mentioned excess base amount can be measured as follows. "Measurement of excess acid amount or excess base amount"
The ionic compound 0.1 g is dissolved in distilled water 9.9 g to prepare a 1% by weight aqueous solution of the ionic compound. This solution is measured for pH with a commercially available pH meter. The solution is subjected to neutralizing titration with a 0.1 M aqueous solution of sodium hydroxide if showing a pH of 7 or less in the measurement. While the pH is measured, the volume of the 0. IM aqueous solution of sodium hydroxide needed until the point of inflection is defined as "V ml", and the excess acid amount X mol/g is calculated from the following formula.
X= 0.1 x f x V/1000/1.0 (f: potency of aqueous solution of sodium hydroxide)
The solution is subjected to neutralizing titration with 0.1 M hydrochloric acid if showing a pH of more than 7 in this measurement. While the pH is measured, the volume of the 0. IM aqueous solution of sodium hydroxide needed until the point of inflection is defined as "V ml", and the excess base amount
Y mol/g is calculated from the following formula.
Y = 0.1 x f x V/1000/1.0 (f: potency of hydrochloric acid) If the 1% by weight aqueous solution of the ionic compound has a pH of 6 to 8, the pH is lowered to 6 or less by adding 0.1 N hydrochloric acid to the solution. Then, the solution may be subjected to titration with a 0.1 N aqueous solution of sodium hydroxide. In this case, the volume of the 0.1 N hydrochloric acid firstly added is defined as VH (potency: fH) and the volume of the 0.1 N aqueous solution of sodium hydroxide added until the point of inflection is definedasVNe (potency : fNe) . Then, the excess acid amount and the excess base amount are calculated from the following formulae, respectively. In VH x fH ≤ VNe * fNe, X = 0.1 x f x (VNe x fNe - VH x fH) /1000/0.1; in VH x fH ≥ VNe * fNe, Y = 0.1 x f x (VH x fH " VNe x fNe) /1000/0.1.
In the present invention, if the above-mentioned moisture content of the ionic compound is more than 1000 ppm and/or the above-mentioned excess acid amount or the above-mentioned excess base amount is 0.2 x 10"3 mol/g or more, reaction with an active substance of a positive electrode or a negative electrode, or deterioration of an electrolyte may be caused in the cases where the ionic compound is used as an electrolyte for lithiumbatteries and the like. Therefore, the functional effects of the present invention of providing an ionic compoundwhich exhibits excellent basic performances such as electrochemical stability and can be preferably used in various applications such as electrochemical devices may be insufficiently exhibited. That is, as mentioned below, lithium with very high reactivity is generated on the negative electrode during discharging.
Therefore, reactions other than the oxidation reduction reaction Of Li → Li+ + e", for example, a reaction of 2Li + 2H2O -> 2LiOH + H2T occurs if the ionic compound used as a material for lithium batteries has a high moisture content and a high impurity amount. Such a reaction interrupts the electrode reactions, and the electrode surface is corroded. Therefore, the battery is prevented from exhibiting stable battery performances. In addition, generation of hydrogen increases the internal pressure, which may cause reduction in safety of the battery. This can be judged from comparison of the battery performances between the battery after a certain charge and discharge cycles in evaluation test of reactivity with a Li-foil electrode and charge and discharge test using a coin battery, mentioned below, and the battery before the tests . That is, an irreversible reaction occurs on the Li-foil surface in the evaluation test of reactivity with a Li-foil electrode and deposits may be produced if the ionic compound satisfies at least one of the embodiments (1) the moisture content is more than 1000 ppm and (2) the excess acid amount or the excess base amount is 0.2 x 10"3 mol/g or more. Even if no deposits are generated on the Li-foil surface in the evaluation test of reactivity with a Li-foil electrode, the irreversible reaction generates inert components inside the electrode in the charge and discharge test using a coin battery. As a result, the discharge capacity after a certain charge and discharge cycle test may be reduced or the resistance between the electrodes may be increased. However, generation of reactions other than the oxidation reduction reaction of Li → Li+ + e" can be prevented if the moisture content is 1000 ppm or less and the excess acid amount or the excess base amount is less than 0.2 x 10"3 mol/g. Therefore, batteries and the like having excellent charge and discharge properties and long-term reliability can be provided.
It is preferable that the ionic compound has a Hazen value of 200 or less. Thereby, the functional effects of the present invention of providing an ionic compoundwhich exhibits excellent basic performances such as electrochemical stability and can be preferably used in various applications can be sufficiently exhibited. The ionic compound more preferably has a Hazen value of 180 or less. The Hazen value can be measured as follows. "Measurement of Hazen value"
The ionic compound 0:1 g is dissolved in distilled water 9.9 g to prepare a 1% by weight aqueous solution of the ionic compound. This solution is measured for Hazen value by comparing the hue with that of a Hazen standard sample by eye observation. In this measurement, the aqueous solution of the ionic compound and the Hazen standard sample are charged into equivalent containers, respectively and compared with each other.
It is preferable that the above-mentioned ionic compound contains 1.5% by weight or less of an amidated product. The content is more preferably 0.5% by weight or less, and still more preferably 0.3% by weight or less, and most preferably 0.2% by weight or less. If the content of the amidated product is more than 1.5% by weight, an irreversible reaction generates inert components on the electrode surface, which affects the electrochemical properties . That is, the irreversible reaction occurs on the Li-foil electrode surface in the evaluation test of reactivity with the Li-foil electrode if the content of the amidated product is more than 1.5% by weight. As a result, deposits may be generated. Even if no deposits are generated on the Li-foil surface in the evaluation test of reactivity with the Li-foil electrode, the irreversible reaction generates inert components inside the electrode in the charge and discharge test using a coin battery. As a result, the discharge capacity after a certain charge and discharge cycle test may be reduced or the resistance between the electrodes may be increased.
As a particularly preferable embodiment of the above-mentioned ionic compound, an embodiment in which the ionic compound contains an amidated product of the dicyanotriazolate anion within the above-mentioned value range, that is, the ionic compound contains the amidated product of preferably 1.5% by weight or less, and more preferably 0.5% by weight or less, and still more preferably 0.3% by weight or less, and most preferably 0.2% by weight or less. The above-mentioned content of the amidated product can be measured as follows. "Determination method of amidated product"
The amidated product is determined using ion chromato ICS-3000, product of DIONEX Corp. An aqueous solution of 1.7 mM-NaHC03/l .8 InM-Na2CO3 is used as an eluent. AS4A-SC is used as a column. The content of the amidated product (the amount of the amidated product) is measured based on the following formula . Amount of amidated product (% by weight) = (proportion obtained from peak area of amidated product) / ( proportion obtained from peak area of LiDCTA + proportion obtained from peak area of amidated product) * 100
It is also preferable that the above-mentioned ionic compound has an impurity content of 0.1% by weight (1000 ppm) or less in 100% by weight of the ionic compound. If the ionic compound is more than 0.1% by weight, the electrochemical stability may be insufficiently obtained. The impurity content is more preferably 0.05% by weight or less, and still more preferably 0.01% by weight or less. The above-mentioned impurity does not contain water, and examples thereof include impurities which are mixed in upon preparation of the ionic compound. Specifically, if an ionic compound essentially containing dicyanotriazolate anion is produced by deriving a halogen compound, for example, the halogen compound may be mixed as an impurity. If the ionic compound is produced by deriving silver salt, the silver salt may be mixed as an impurity. Production raw materials, byproducts, and the like also may be mixed as impurities. If the above-mentioned impurity content in the ionic compound is determined as mentioned above in the present invention, for,example, it becomes possible to sufficiently suppress deterioration of performances due to poisoning of an electrode in an electrochemical device by the halogen compound, or sufficiently suppress deterioration of performances due to influence of the silver ion or the like on the ionic conductivity. The impurity content is preferably measured by the following measurement method. (Measurement method of impurities)
(1) ICP (measurement of cations such as silver ion and iron ion) Instrument: ICP light emitting spectrophotometry apparatus called SPS4000 (manufactured by Seiko Instruments Inc.)
Method: A sample 0.3 g is 10-fold diluted with ion-exchanged water, and the resulting solution is measured.
(2) Ion chromatography
(Measurement of anions such as nitric acid ion, bromine ion, and chlorine ion)
Instrument: ion chromatography system called DX-500
(manufactured by Nippon Dionex Co., Ltd.)
Separation mode: ion exchange
Detector: electric conductivity detector called CD-20 Column: AS4A-SC Method: A sample 0.3 g is 100-fold diluted with ion-exchanged water, and the resulting solution is measured.
The above-mentioned ionic compound contains a cation and an anion. The above-mentioned cation is preferably at least one cation selected from the group consisting of cations represented by the following formula (1) and alkali metal ions.
Rs L ( 1 )
(in the formula, L representing at least one element selected from the group consisting of C, Si, N, P, S, and 0; R being the same or different and each representing a monovalent element or an organic group, and may be bonded together; and s being an integer of 3 to 5 and being a value determined by the valency of the element L) . The above-mentioned anion is preferably dicyanotriazolate anion and representedby the following formula
(2) :
Figure imgf000016_0001
As mentioned above, if the triazole ring contains two cyano groups, the electric absorption increases and the acidity can be higher. Therefore, such an anion can be sufficiently stabilized.
The ionic compound may contain anions other than the above-mentioned dicyanotriazolate anion, or cations other than the above-mentioned cation.
The ionic compound of the present invention contains the above-mentioned cation containing a monovalent element or an organic group and the dicyanotriazolate anion. Therefore, the ionic compound can be easily dissolved in a matrix (solvent and the like) as compared with inorganic salts such as lithium salts . Therefore, such a compound can be excellent in various physical properties and can be preferably applied in various applications such as materials for electrochemical devices. As mentioned above, the present invention includes an ionic compound containing a dicyanotriazolate anion and the cation represented by the above formula (1).
The ionic compound of the present invention can exhibit excellent basic performances such as electrochemical stability if containing an alkali metal ion and the dicyanotriazolate anion . Therefore, such an ionic compound can be preferably used in various applications such as materials for electrochemical devices .
In the above formula (1) , L represents at least one element selected from the group consisting of C, Si, N, P, S, and 0. L is preferably an element of N, P, and S, and more preferably an element of N.
The above-mentioned R are the same or different and each represent a monovalent element or an organic group, and may be bonded together. Preferred examples of the above-mentioned monovalent element or the above-mentioned organic group include hydrogen element, fluorine element, amino group, imino group, amide group, ether group, ester group, hydroxyl group, carboxyl group, carbamoyl group, cyano group, sulfone group, sulfide group, vinyl group, C1 to C18 hydrocarbon group, and C1 to C18 fluorocarbon group. Each of the above-mentioned C1 to C18 hydrocarbon group and the above-mentioned C1 to C18 fluorocarbon group may have a straight chain, a branched chain, or a ring structure, and may contain a nitrogen element, an oxygen element, and a sulfur element. Such groups preferably contain 1 to 18 carbon atoms, and more preferably 1 to 8 carbon atoms. More preferred examples of the above-mentioned monovalent element or the above-mentioned organic group include hydrogen element, fluorine element, cyano group, sulfone group, C1 to C8 hydrocarbon group, oxygen atom-containing C1 to C8 hydrocarbon group, and C1 to C8 fluorocarbon group. Still more preferred is hydrogen element. As mentioned above, the preferable embodiments of the present invention include such an ionic compound wherein at least one of R in the above formula (1) is hydrogen element.
The above-mentioned "s" is an integer of 3 to 5 and a value determined by the valency of the element L. If L is C or Si, s is 5. If L is N or P, s is 4. If L is S or 0, s is 3. That is, cations represented by the following formula (1-1) :
Figure imgf000018_0001
(1-1)
Figure imgf000018_0002
(in the formula, R are the same as in the above formula (1) are preferable as the cation represented by the above formula (1) ) .
The above-mentioned cation is not especially limited as long as it satisfies the above-mentioned formula (1) . Among them, onium cations represented by the following (I) to (IV) are more preferable. The onium cation means an organic group having a cation of a non-metal element such as O, N, S and P or a semi-metal element.
The above-mentioned onium cations (I) to (IV) arementioned below.
In the following formulae, R4 to R15 are the same or different and each represent a monovalent element or an organic group and may be bonded together. (I) Ten species of heterocyclic onium cations represented by the following formula (1-1) :
Figure imgf000019_0001
(II) Five species of unsaturatVd'"ohiύm cations represented by the following formula (l-II):
Figure imgf000020_0001
(1 - I I )
Figure imgf000020_0002
(III) Nine species of saturated ring onium cations represented by the following formula (l-III):
Figure imgf000020_0003
Figure imgf000020_0004
(IV) Chain onium cations in which R are C1 to C8 alkyl groups.
More preferred among such onium cations are those in which L in the above formula (1) is nitrogen element. Still more preferred are six species of onium cations represented by the following formula (1-2) (in the formula, R4 to R15 are the same as those mentioned above) and chain onium cations such as triethylmethylammonium, dimethyIethylpropylammonium, diethylmethylmethoxyethylammonium, trimethylpropylammonium, trimethylbutylammonium, and trimethylhexylammonium.
Figure imgf000021_0001
Preferred examples of the above-mentioned monovalent element or the above-mentioned organic group in R to R include hydrogen element, fluorine element, amino group, imino group, amide group, ether group, ester group, hydroxyl group, carboxyl group, carbamoyl group, cyano group, sulfone group, sulfide group, vinyl group, C1 to C18 hydrocarbon group, and C1 to C18 fluorocarbon group. Each of the above-mentioned C1 to C18 hydrocarbon group and the above-mentioned C1 to C18 fluorocarbon group may have a straight chain, a branched chain, or a ring structure, and may contain a nitrogen element, an oxygen element, and a sulfur element. Such groups preferably contain 1 to 18 carbon atoms, and more preferably contain 1 to 8 carbon atoms.
More preferred examples of the above-mentioned monovalent element or the above-mentioned organic group include hydrogen element, fluorine element, cyano group, sulfone group, C1 to C8 hydrocarbon group, oxygen atom-containing C1 to C8 hydrocarbon group, and C1 to C8 fluorocarbon group.
Compounds composed of such an onium cation and the above-mentioned anion can occur as anordinary temperature moIten salt capable of stably retaining its molten state at ordinary temperatures. Ionic composition containing such a molten salt can be preferably used as a material for ionic conductors of electrochemical devices capable of enduring long-term use . The molten salt means a salt capable of retaining its liquid state stably at temperatures of 800C or less.
The above-mentioned ionic compound containing the dicyanotriazolate anion and the cation represented by the above formula (1) preferably has an embodiment (1) the compound essentially contains a nitrogen heterocyclic cation having a conjugated double bond, or an embodiment (2) in the above formula (I)/ L is N, and R are the same or different and each represent a hydrogen atom or R1 to R3 representing a C l to C8 hydrocarbon group. In the above-mentioned embodiment (1), as the nitrogen heterocyclic cation having a conjugated double bond , preferred are the cations having a conjugated double bond, in which L is nitrogen element in the above formula (1), among ten species of heterocyclic onium cations of the above-mentioned (I) and five species of unsaturated onium cations of the above-mentioned ( H ) •
In the above-mentioned embodiment (2), if at least two of R1 to R3 are hydrocarbon groups, these hydrocarbon groups may be directly bonded to each other, or may have a structure in which the groups are bonded with at least one element selected from the group consisting of O, S, and N therebetween. As mentioned above, the present invention also includes an ionic compound containing a dicyanotriazolate anion and a cation represented by the following formula (3) :
Figure imgf000023_0001
(in the formula, R1 to R3 being the same or different and each representing hydrogen element or a C1 to C8 hydrocarbon group; if at least two of R1 to R3 being hydrocarbon groups, these hydrocarbon groups may be directly bonded or may have a structure in which the groups are bonded with at least one element selected from the group consisting of 0, S, and N therebetween) . It is preferable that such an ionic compound also satisfies at least one of the preferable value ranges in the above-mentioned various physical properties (moisture content, excess acid amount or excess base amount, Hazen value, and amidated product content) . With respect to the cation contained in the ionic compound of the present invention, the alkali metal ion is not especially limited. Examples thereof include lithium ion, sodium ion, potassium ion, rubidium ion, caesium ion, and francium ion. Among them, it is preferable that at least lithium ion is contained. As a result, the ionic conductivity, the electrochemical stability, or the like can be sufficiently improved.
Such an ionic compound containing lithium ion and dicyanotriazolate anion is also referred to as "lithium dicyanotriazolate" . The present invention also relates to an ionic compound comprising a dicyanotriazolate anion, wherein the ionic compound contains 1.5% by weight or less of an amidated product of the dicyanotriazolate anion.
In such an ionic compound, the dicyanotriazolate anion is as mentioned above. If the content of the amidated product of the anion is more than 1.5% by weight, an irreversible reaction generates inert components on the electrode surface, which affects the electrochemical properties. That is, the irreversible reaction occurs on the Li-foil surface in the evaluation test of reactivity with the Li-foil electrode if the content of the amidated product is more than 1.5% by weight. As a result, deposits may be generated. Even if no deposits are generated on the Li-foil surface in the evaluation test of reactivity with the Li-foil electrode, the irreversible reaction generates inert components inside the electrode in the charge and discharge test using a coin battery. As a result, the discharge capacity after a certain charge and discharge cycle test maybe insufficient or the resistance between the electrodes may be increased. The above-mentioned content of the amidated product is preferably 0.5% by weight or less, and more preferably 0.3% by weight or less, and still more preferably 0.2% by weight or less .
The above-mentioned content of the amidated product can be measured as mentioned above. The above-mentioned ionic compound preferably satisfies the above-mentioned value ranges in various physical properties such as moisture content, excess acid amount or excess base amount, and Hazen value.
As such a cation contained in the above-mentioned ionic compound, preferred is at least one cation selected from the group consisting of cations represented by the above formula
(1) and alkali metal ions. Lithium ion is more preferred. The preferable embodiments of the present invention include an embodiment in which the above-mentioned ionic compound contains a lithium ion. The above-mentioned lithium dicyanotriazolate is a compound having a structure represented by the following formula (7) .
Figure imgf000025_0001
As a particularly preferable embodiment of the above-mentioned lithium dicyanotriazolate is an embodiment in which the lithium dicyanotriazolate has: a moisture content of 1000 ppm or less; and an excess acid amount or an excess base amount of less than 0.2 * 10"3 mol/g. In such an embodiment, the functional effects of the present invention of providing an ionic compound which exhibits excellent basic performances such as electrochemical stability and can be preferably used in various applications can be sufficiently exhibited.
The production method of the ionic compound of the present invention is not especially limited. A method including a step of deriving an ionic compound from a compound containing dicyanotriazolate anion (for example, dicyanotriazole) is preferable. Thereby, it becomes possible that the ionic compound has a form preferable as a molten salt or a salt constituting a solid electrolyte. Such a production method preferably includes a step of deriving an ionic compound from a compound having a dicyanotriazolate anion structure using a halide or a carbonated product. For example, preferred is a method of including a step of reacting a compound having dicyanotriazolate anion with a halide or a carbonated product, wherein the halide or the carbonated product contains an onium cation or a cation essentially containing at least one metal atom selected from the group consisting of alkali metal atoms, alkaline earthmetal atoms, transitionmetal atoms and rare earth metal atoms. One or two or more species of each of these production raw materials may be used. In the above-mentioned production method, an anion exchange resin is preferably used in the above-mentioned production method.
The above-mentioned production method may include a step of synthesizing the compound containing dicyanotriazolate anion used in the above-mentioned step of deriving an ionic compound from a compound containing dicyanotriazolate. In this case, the compound containing dicyanotriazolate anion is preferably synthesizedby reacting the above-mentioned compound containing dicyanotriazolate anion with a halide or a carbonated product. Thereby, it becomes possible to appropriately determine the structure of the dicyanotriazolate anion in the above-mentioned ionic compound, depending on performances and the like needed for the above-mentioned ionic composition. In this case, the anion contained in the compound containing the anion which is a production raw material used in the step of synthesizing the compound containing dicyanotriazolate anion is not the same as the dicyanotriazolate anion contained in the ionic compound. If dicyanotriazole (HDCTA) is used as the above-mentioned compound containing dicyanotriazolate anion, the step of synthesizing the HDCTA is preferably as follows. The above-mentioned step of synthesizing HDCTA includes the steps of : synthesizing dicyanotriazole (HDCTA) bydispersing diaminomaleonitrile into an acid aqueous solution and adding sodium nitrite into the dispersion solution; adding an organic solvent into the solution after the reaction to perform extraction; andpurifying the extractedsubstance to obtainHDCTA. Examples of the above-mentioned acid aqueous solution used for dispersing diaminomaleonitrile include aqueous solutions prepared by dissolving the following compounds in water.
Mineral acids such as sulfuric acid, hydrochloric acid, hydrogen bromide, nitric acid, and phosphoric acid; halogenated carboxylic acids such as chloroacetic acid, dichloroacetic acid, trichloroacetic acid, and trifluoroacetic acid; and sulfonic acids such as methansulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and dodecylbenzenesulfonic acid. An aqueous solution prepared by dissolving sulfuric acid in water is preferable in view of preventing corrosion of a reaction kettle, The above-mentioned diarainomaleonitrile preferably accounts for 5 to 70%, andmore preferably 10 to 50% relative to the reaction mixture . The addition amount of the above-mentioned sodium nitrite is preferably 1.00 to 1.15 times greater than the amount of HDCTA. Thereby, the Hazen value of the ionic compound of the present invention can be effectively reduced. The addition amount is more preferably 1.03 to 1.12 times. In the above-mentioned synthesis of HDCTA, the sodium nitrite may be added in solid form or in aqueous solution form.
Preferably, the sodium nitrite is added in aqueous solution form.
In the above-mentioned extraction using an organic solvent, dicyanotriazole (HDCTA) is synthesized and then an organic solvent is added to the reaction liquid to perform the extraction. In this case, it is preferable that a substance obtained by drying and solidify the obtained solid substance (HDCTA) is extracted using an organic solvent. Thereby, the Hazen value of the obtained ionic compound can be effectively reduced. The above-mentioned solvent used for the extraction is not limited. Preferred examples thereof include ether solvents such as diisopropyl ether, diethyl ether, dipropyl ether, methylbutyl ether, and dibutyl ether; solvents containing an ether group or an ester group derived from ethylene glycols or propylene glycols, for example, cyclic ethers such as tetrahydrofuran and dioxane, dimethoxyethane, methyl cellosolve, ethyl cellosolve, and methoxy propylene glycol; ketone solvents such as methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, ethyl butyl ketone, ethyl isobutyl ketone, and cyclopentanone; ester solvents, such as ethyl acetate, propyl acetate, and butyl acetate. More preferred are ether solvents such as diethyl ether, dipropyl ether, diisopropyl ether, methylbutyl ether, and dibutyl ether; and ester solvents such as ethyl acetate, propyl acetate, and butyl acetate. Examples of the method of the above-mentionedpurification of HDCTA include: a method of subjecting the solution containing HDCTA after the extraction to activated carbon treatment, extraction or crystallization; and a method of subliming the obtained HDCTA by removing or crystallizing the solvent used for the extraction. These methods may be' employed singly or in combination. Among them, the purification is preferably performed by sublimation.
The sublimation temperature is preferably 120 to 130°C in view of reduction in sublimation time. If the sublimation temperature is more than 130°C, side reaction such as decomposition or amidation of HDCTA may occur, which is not preferable . The sublimation temperature is more preferably 123 to 127°C. The sublimation pressure is preferably 50 Pa or less, and more preferably 30 Pa or less. The number of times of the sublimination of the HDCTA is not especially limited. The sublimination of the HDCTA is preferably preformed one time in view of economical efficiency. Thus, the preferable embodiments of the present invention include an embodiment in which the above-mentioned ionic compound is synthesized using HDCTA purified by sublimation.
In the above-mentioned step of deriving an ionic compound from a compound containing dicyanotriazolate anion, one embodiment of the chemical reaction formula in this step is shown in the following formula (1) .
Figure imgf000029_0001
In the above-mentioned step, the molar number of the compound containing dicyanotriazolate anion is represented by "a" and the. molar number of the halide is represented by "b", the molar ratio (a/b) in the reaction is preferably 100/1 to 0.1/1. If the above-mentioned compound containing dicyanotriazolate anion is less than 0.1, the halide is excessive, which may fail to generate a product effectively. In addition, the halogen may be mixed in the ionic composition and thereby electrodes and the like may be poisoned. If the above-mentioned compound containing dicyanotriazolate anion is more than 100, the compound is excess and therefore improvement in yield may not be expected any more. In addition, the metal ion is mixed in the ionic composition and thereby performances of electrochemical devices may be reduced. The molar ratio is preferably 10/1 to 0.5/1.
The reaction conditions in the above-mentioned step may be appropriately determined depending on the production raw materials, other reaction conditions, and the like. The reaction temperature is preferably -20 to 200°C, and more preferably 0 to 100°C, and furthermore preferably 10 to 60°C. The reaction pressure is preferably 1 * 102 to 1 * 108 Pa, and more preferably 1 * 103 to 1 * 107 Pa, and still more preferably 1 x 104 to 1 x 106 Pa. The reaction time is preferably 48 hours or less, and more preferably 24 hours or less, and still more preferably 12 hours or less. In the above-mentioned step, a reaction solvent is usually used. Examples of such a reaction solvent include (1) aliphatic hydrocarbons such as hexane and octane; (2) alicyclic saturated hydrocarbons such as cyclohexane; (3) alicyclic unsaturated hydrocarbons such as cyclohexne; (4) aromatic hydrocarbons such as benzene, toluene and xylene; (5) ketones such as acetone and methyl ethyl ketone; (6) esters such as methyl acetate, ethyl acetate, butyl acetate and γ-butyrolactone; (7) halogenated hydrocarbons such as dichloroethane, chloroform and carbon tetrachloride; (8) ethers such as diethyl ether, dioxane and dioxolane; (9) ethers of alkylene glycols such as propylene glycol monomethyl ether acetate and diethylene glycol monomethyl ether acetate; (10) alcohols such as methyl alcohol, ethyl alcohol, butyl alcohol, isopropyl alcohol, ethylene glycol and propylene glycol monomethyl ether; (11) amides such as dimethylformamide and N-methylpyrrolidone; (12) sulfonic acid esters such as dimethyl sulfoxide; (13) carbonic acid esters such as dimethyl carbonate and diethyl carbonate; (14) alicyclic carbonic acid esters such as ethylene carbonate and propylene carbonate; (15) nitriles such as acetonitrile; and (16) water. One or two or more species of them may be used. Among them, preferred are the solvents mentioned in (5) , (6) , (10) , (11) , (12), (13), (14), (15) , and (16) . Morepreferredare the solvents mentioned in (5), (10), (15), and (16).
If the above-mentioned ionic compound is lithium dicyanotriazolate, the above-mentioned step is preferably performed as follows.
The above-mentioned step of synthesizing lithium dicyanotriazolate (LiDCTA) is preferably a step of synthesizing lithium dicyanotriazolate (LiDCTA) by adding a lithiation reagent to HDCTA and drying the synthesized lithium dicyanotriazolate. Examples of the lithiation reagent include lithium carbonate, lithium hydroxide, and lithium metal. Lithium carbonate is preferably used because lithium carbonate with high purity is commercially available and therefore easily obtained.
In the above-mentioned step of synthesizing LiDCTA, the reaction temperature is preferably 500C or less . If the reaction temperature is more than 50°C, the cyano groups are additionally reacted with water to generate byproducts. The solvent used in the above-mentioned step of synthesizing LiDCTA is not especially limited. The following two preferable embodiments may be mentioned in reaction of HDCTA with an equivalent amount of the lithiation reagent. One is a method using water as the solvent . Thereby, HDCTCA is reacted with an equivalent amount of the lithiation reagent to complete the reaction in one stage. In this case, the reaction is preferably completed at pH of 6 to 8 as a terminal point. If the pH is lower than 6 or higher than 8, the acids or the bases excessively remain in the system despite use of water, which is not preferable. The other method is a method using a solvent other than water. In this case, the reaction is not completed when HDCTA is reacted with an equivalent amount of the lithiation reagent, and the acids or the bases may remain in the system. Also in this case, the reaction is preferably completed at pH of 6 to 8 as a terminal point. If the pH is lower than 6 or higher than 8, the acids or the bases more excessively remain in the system despite use of water, which is not preferable. In this case, the excess acids or bases can be removed by purification after the reaction. In the above-mentioned production method of the ionic compound, treatments such as filtration of precipitates and the like, removal of the solvent, dehydration, and drying under reducedpressure maybe performed after the above-mentioned steps. For example, the above-mentioned ionic composition essentially containing the ionic compound may be obtained by the following method: the generatedprecipitate is filtered to obtain a solvent containing the ionic compound; the solvent is removed under vacuum or the like condition; the obtained substance is washed by dissolved in a solvent such as dichloromethane; the washed substance is dehydrated by adding a substance having dehydration effect such as MgSO4 thereto; and the dehydrated substance is dried under reduced pressure after removal of the solvent. The number of times of the detergency with the solvent may be appropriately determined. Preferred examples of the solvent include: ketones such as chloroform, tetrahydrofuran, and acetone; ethers such as ethylene glycol dimethyl ether; acetonitrile; and water, in addition to dichloromethane. Preferred examples of the substance having dehydration effect includemolecular sieve, CaCl2, CaO, CaSO4, K2CO3, active alumina, and silica gel, in addition to MgSO4. The addition amount of such a substance may be appropriately determined depending on the kind of the product or the solvent.
In the above-mentioned production method of the ionic compound, purification may be performed if necessary. The purification method is not especially limited. Examples thereof include activated carbon treatment, extraction, and crystallization eachusing a solvent which can dissolve theάonic compound therein.
Examples of the method of the above-mentioned drying of the ionic compound include reduced pressure drying, fluidized bed drying, solvent azeotropydrying, spray drying, andmolecular sieve drying. These methods may be employed singly or in combination.
Examples of solvents used in the solvent azeotropy include ether solvents such as toluene, hexane, cyclohexane, diethyl ether, dipropyl ether, diisopropyl ether, methylbutyl ether, tetrahydrofuran, dioxane, 1, 2-dimethoxyethane; nitrile solvents, such as acetonitrile and propionitrile; alcohol solvents such as ethanol, propanol, isopropanol, and butanol; ketone solvents, such as acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, diethyl ketone, ethyl butyl ketone, ethyl isobutyl ketone, and cyclopentanone; ester solvents, such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; and carbonate solvents, such as dimethyl carbonate. Toluene and acetonitrile are preferable in view of drying rate.
Dehydrated solvents are preferably used as the above-mentioned solvent in view of drying rate. The method of dehydrating the solvent is not especially limited. A dehydration method using a molecular sieve may be mentioned.
In the above-mentioned solvent azeotropy, the azeotropy temperature is preferably 40°C or more and 140°C or less. If the azeotropy temperature is lower than 400C, the azeotropic composition formed of water and the azeotropic solvent shifts to the azeotropic solvent, and therefore the drying efficiency is reduced, which is not preferably. The azeotropy temperature of more than 1400C is not preferable because the above-mentioned byproducts causing the amidation may be extremely generated.
The following method is mentioned as a preferable embodiment of efficiently performing the azeotropic dehydration while suppressing the generation of the above-mentioned amidated products. That is, a method of performing dehydration at low temperatures in an initial dehydration step in which the reaction system has a large moisture content and then raising the temperature while confirming the amount of reduced moisture in the system. The time needed for such an azeotropic dehydration step is not especially limited. It is preferable that the azeotropic dehydration is performed for a proper time while confirming the moisture amount in the system. If the azeotropic dehydration time is short, the ionic compound is not dried until a desired moisture amount, which is not preferable. If the azeotropic dehydration is too long, residual moisture allows the amidation reaction to proceed, which is not preferable.
In drying using a molecular sieve, the above-mentioned ionic compound is dissolved in a solvent and treated by addition of a commercially available molecular sieve . Then, the solvent is dried. As a result, the moisture in the above-mentioned ionic compound can be reduced.
Examples of the above-mentioned solvent in which the ionic compound is dissolved include methanol, ethanol, n-propanol, isopropanol, n-butanol, s-butanol, t-butanol, acetone, methyl ethyl ketone, acetonitrile, and propylene carbonate. However, it is preferable that the solvent is selected depending on use conditions of' the above-mentioned ionic compound because a step of drying such a solvent is needed.
The molecular sieve added is not especially limited. Commercially available various molecular sieves may be used. However, it is preferable that the molecular sieve is selected depending on use conditions of the above-mentioned ionic compound because elution from the molecular sieve may occur . If the ionic compound is used for lithiumbatteries, Li-Aand the like obtained from UNION SHOWA K. K., in which the sodium constituting the molecular sieve is substituted with lithium is preferably used.
In the above-mentioned steps of producing the ionic compound, it is preferable that the above-mentioned drying of the ionic compound is performed by molecular sieve and toluene azeotropy. Thereby, the above-mentioned moisture amount in the ionic compound can be effectively reduced.
In a step of degassing the solvent in the above-mentioned ionic compound, the drying temperature is preferably 140°C or less. If the drying temperature is more than 1400C, the above-mentioned byproducts causing the amidation reaction may be extremely generated.
A particularly preferable embodiment as the above-mentioned production method of the ionic compound is an embodiment in which the production method includes the steps of : synthesizing a compound containing dicyanotriazolate anion; synthesizing an ionic compound containing the anion; and drying the ionic compound. That is, the above-mentioned ionic compound is preferably produced by the production method including these steps .
The above-mentioned various ionic compounds of the present invention have the above-mentioned configuration. Therefore, such ionic compounds can exhibit excellent basic performances such as electrochemical stability and can be particularly preferable as amaterial for ionic conductors of electrochemical devices capable of enduring long-term use . As mentioned above, the preferable embodiments of the present invention include an ionic composition containing the above-mentioned ionic compound preferably used as a material for ionic conductors.
The above-mentioned ionic composition is mentioned below.
-Ionic composition-
The above-mentioned ionic compositionmay contain an onium cation-containing organic compound other than the above-mentioned organic salts essentially containing onium cations .
Organic compounds containing an onium cation and the following anion may be mentioned as such an onium cation-containing organic compound.
Halogen anions (fluoro anion, chloro anion, bromo anion, iodo anion) , a borate tetrafluoride anion, a phosphate hexafluoride anion, an aluminate tetrafluoride anion, an arsenate hexafluoride anion, a sulfonylimide anion represented by the following formula (4), a sulfonylmethide anion represented by the following formula (5) , and organic carboxylic acids (anions of acetic acid, trifluoroacetic acid, phthalic acid, maleic acid, benzoic acid and the like) . In addition, fluorine-containing inorganic ions such as a hexafluorophosphoric acid ion, a hexafluoroarsenic acid ion, a hexafluoroantimonic acid ion, a hexafluoroniobic acid ion, and a hexafluorotantalic acid ion; carboxylic acid ions such as a hydrogen phthalate ion, a hydrogen maleate ion, a salicylic acid ion, a benzoic acid ion, and an adipic acid ion; sulfonic acid ions such as a benzenesulfonic acid ion, a toluenesulfonic acid ion, a dodecylbenzenesulfonic acid ion, a trifluoromethanesulfonic acid ion, and a perfluorobutanesulfonic acid ion; inorganic oxoacid ions such as a boric acid ion, and a phosphoric acid ion; bis (trifluoromethanesulfonyl) imide ion, bis (pentafluoroethanesulfonyl ) imide ion, tris (trifluoromethanesulfonyl) methide ion, perfluoroalkylfluoroborate ion, perfluoroalkylfluorophosphate ion, borodicatecholate, borodiglycholate, borosalicylate, borotetrakis ( trifluoroacetate) , and tetradentate boric acid ions such as bis (oxalate) borate.
U N(SO2R16XSO2R17) ( 4 )
~ C(SO2R16)(SO2R17)(SO2R18) ( 5 )
In the above formulae, R16, R17, and R18 may be the same or different and each represent a C1to C4 perfluoroalkyl group which may optionally have one or two ether groups.
With respect to the amount of the above-mentioned onium cation present in the above-mentioned ionic composition, the lower limit is preferably 0.5 mol, and more preferably 0.8 mol, relative to the above-mentioned anion 1 mol. The upper limit is preferably 2.0 mol, and more preferably 1.2 mol.
The above-mentioned ionic composition may contain an alkali metal salt and/or an alkaline earth metal salt. Such an ionic composition containing an alkali metal salt and/or an alkaline earth metal salt contains the alkali metal salt and/or the alkaline earth metal salt as an electrolyte, and preferably serves as a material for ionic conductors of electrochemical devices. Such an alkali metal salt includes lithium salts, sodium salts and potassium salts. Such an alkaline earth metal salt includes calcium salts and magnesium salts. Lithium salts are more preferred. The above-mentioned alkali metal salt and/or the above-mentioned alkaline earth metal salt may be an ionic compound essentially containing the above-mentioned anion or may be a compound other than the ionic compound. Alkali metal salts and/or alkaline earth metal salts of dicyanotriazolate anion are preferable if the above-mentioned alkali metal salt and/or the above-mentioned alkaline earthmetal salt are/is the above-mentioned ionic compound (s) essentially containing the anion. For example, lithium salt of dicyanotriazolate anionmaybe usedas the above-mentionedalkali metal salt and/or the above-mentioned alkaline earth metal salt . Lithium salts may be used as other alkali metal salts and/or alkaline earth metal salts . Preferable examples of such lithium salts include LiC (CN) 3, LiSi (CN) 3, LiB (CN) 4, LiAl (CN) A, LiP (CN) 2, LiP(CN)6, LiAs(CN)6, LiOCN, and LiSCN.
Electrolyte salts showing a high dissociation constant in an electrolytic solution or a polymer solid electrolyte are preferable in compounds other than the above-mentioned ionic compound. Preferred examples thereof include alkali metal salts and alkaline earthmetal salts of trifluoromethanesulfonic acid such as LiCF3SO3, NaCF3SO3 and KCF3SO3; alkali metal salts and alkaline earth metal salts of perfluoroalkanesulfonimide, such as LiN (CF3SO3) 3 and LiN (CF3CF3SO2) i) alkali metal salts and alkaline earth metal salts of hexafluorophosphoric acid, such as LiPF6, NaPF6 and KPF6; alkali metal salts and alkaline earth metal salts of perchloric acid, such as LiClO4 and NaClO4; tetrafluoroborate salts such as LiBF4 and NaBF4 ; and alkali metal salts such as LiAsF6, LiI, NaI, NaAsF6 and KI. Among them, LiPF6, LiBF4, LiAsF6, and alkali metal salts or alkaline earth metal salts of perfluoroalkanesulfonimide are preferred in view of solubility and ionic conductivity.
The above-mentioned ionic composition may contain another electrolyte salt. Preferred examples thereof include perchloric acid quaternary ammonium salts such as tetraethylammonium perchlorate; tetrafluoroboric acid quaternary ammonium salts such as (C2Hs)4NBF4, quaternary ammonium salts such as (C2Hs)-(NPF6; and quaternary phosphonium salts such as (CH3) 4P-BF4, and (C2HB)4P-BF4. Quaternary ammonium salts are more preferred in view of solubility and ionic conductivity.
With respect to the amount of the above-mentioned electrolyte salt present in the ionic composition, it is preferable that the lower limit is 0.1% by weight and the upper limit is 50% by weight in 100% by weight of the ionic composition. If the amount is less than 0.1% by weight, the absolute ion amount is insufficient, possibly leading to a low ionic conductivity. If the amount is more than 50% by weight, the migration of the ions maybe greatly inhibited. The upper limit is more preferably 30% by weight. If the above-mentioned ionic composition contains aproton, such an ionic composition can be preferably used as a material for ionic conductors constituting hydrogen batteries. In the present invention, the proton can occur in the ionic composition of the present invention if the ionic composition contains a compound capable of generating a proton upon dissociation.
With respect to the amount of the above-mentioned proton present in the ionic composition, it is preferable that the lower limit is 0.01 mol/L, and the upper limit is 10 mol/L. If the amount is less than 0.01 mol/L, the absolute proton amount may be insufficient, possibly leading toa lowprotonic conductivity . If the amount is more than 10 mol/L, the migration of the protons may be greatly inhibited. The upper limit is more preferably 5 mol/L or less.
The above-mentioned ionic composition is solidified if containing a polymer. Such a solidified composition can be preferably used as a polymer solid electrolyte. In addition, if such a solidified composition contains a solvent, the ionic conductivity is more improved.
Examples of the above-mentioned polymer include polyvinyl polymers such as polyacrylonitrile, poly (meth) acrylic acid esters, polyvinyl chloride, and polyvinylidene fluoride; polyoxymethylene; polyether polymers such as polyethylene oxide, and polypropylene oxide; polyamide polymers such as nylon 6, and nylon 66; polyester polymers such as polyethylene terephthalate; polystyrene, polyphosphazenes, polysiloxane, polysilane, polyvinylidene fluoride, polytetrafluoroethylene, polycarbonate polymers, and ionene polymers . One or two or more species of them can be preferably used:
If the above-mentioned ionic composition is used as a polymer solid electrolyte, with respect to the amount of the polymer present in the ionic composition, it is preferable that the lower limit is 0.1% by weight and the upper limit is 5000% by weight relative to 100% by weight of the ionic composition. If the amount is less than 0.1% by weight, the effect attributed to the solidification may be insufficiently improved. If the amount is more than 5000% by weight, the ionic conductivity may be reduced. The lower limit is more preferably 1% by weight and the upper limit is more preferably 1000% by weight.
Solvents capable of improving the ionic conductivity are used as the above-mentioned solvent. Water, organic solvents, and the like are preferably used, for example. As the above-mentioned organic solvents, preferably used are compounds having: better compatibility with the above-mentioned components in the ionic composition; a large dielectric constant; a high solubility in the electrolyte salt; a boiling point of 600C or more; and a wide electrochemical stable range . Organic solvents having a low moisture content (non-aqueous solvents) are more preferred. Preferred examples of such organic solvents include ethers such as 1, 2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, crown ether, triethylene glycol methyl ether, tetraethylene glycol dimethyl ether, anddioxane; carbonates such as ethylene carbonate, propylene carbonate, diethyl carbonate, and methylethyl carbonate; chain carbonic acid esters such as dimethyl carbonate, ethylmethyl carbonate, diethyl carbonate, diphenyl carbonate, and methylphenyl carbonate; cyclic carbonic acid esters such as ethylene carbonate, propylene carbonate, ethylene 2, 3-dimethylcarbonate, butylene carbonate, vinylene carbonate, and ethylene 2-vinylcarbonate; aliphatic carboxylic,acid esters such as methyl formate, methyl acetate, propionic acid, methyl propionate, ethyl acetate, propyl acetate, butyl acetate, and amyl acetate; aromatic carboxylic acid esters such as methyl benzoate and ethyl benzoate; carboxylic acid esters such as γ-butyrolactone, γ-valerolactone, δ-valerolactone; phosphoric acid esters such as trimethyl phosphate, ethyldimethyl phosphate, diethylmethyl phosphate, and triethyl phosphate; nitriles such as acetonitrile, propionitrile, methoxy propionitrile, glutaronitrile, adiponitrile, and 2-methylglutaronitrile; amides such as N-methylformamide, N-ethylformamide, N, N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidinone,
N-methylpyrrolidone, and N-vinylpyrrolidone; sulfur compounds such as dimethylsulfone, ethylmethylsulfone, diethylsulfone, sulfolane, 3-methylsulfolane, and 2, 4-dimethylsulfolane; alcohols such as ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether; ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, 1,4-dioxane, 1, 3-dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, 2, 6-dimethyltetrahydrofuran, and tetrahydropyran; sulfoxides such as dimethyl sulfoxide, methylethyl sulfoxide, and diethyl sulfoxide; aromatic nitriles such as benzonitrile, and tolunitrile; nitromethane, 1, 3-dimethyl-2-imidazolidinone,
1, 3-dimethyl-3, 4, 5, 6-tetrahydro-2 (IH) -pyrimidinone, and 3-methyl-2-oxazolidinone . One or two or more species of them can be preferably used. Among them, carbonic acid esters, aliphatic esters and ethers are more preferable, and carbonates such as ethylene carbonate and propylene carbonate are still more preferable, and cyclic esters such as γ-butyrolactone and γ-valerolactone are most preferable. The content of the above-mentioned solvent is preferably 1 to 99% by weight in 100% by weight of the ionic composition. If the content is less than 1% by weight, the ionic conductivity is insufficiently improved. If the content is more than 99% by weight, the stability is insufficiently improved due to volatilization of the solvent. The lower limit of the content is preferably 1.5% by weight, and more preferably 20% by weight, and still more preferably 50% by weight. The upper limit of the content is preferably 85% by weight, and more preferably 75% by weight, and still more preferably 65% by weight. The solvent amount is preferably within a range of 50 to 85% by weight .
The above-mentioned ionic composition has a reduced volatile content and is not frozen, for example, at a low temperature of -55°C. Further, the ionic composition is excellent in ionic conductivity. Therefore, such an ionic composition can exhibit excellent basic performances if used as an electrolytic solution.
The above-mentioned ionic composition may contain one or two or more species of components other than those mentioned above unless the effects of the present invention are sacrificed. For example, if the ionic composition contains various inorganic oxides in minute particle form, the composition may be also used as a composite electrolyte. As a result, not only the strength and the film thickness uniformity are improved, but also fine voids are generated between the inorganic oxide and the above-mentioned polymer . Particularly if the solvent is added, a free electrolytic solution is dispersed in the voids in the composite electrolyte . As a result, the ionic conductivity and the migration degree can be increased without deteriorating strength-improving effects. Inorganic oxides in minute particle form which show no electronic conductivity and are electrochemically stable are preferable as the above-mentioned inorganic oxides in minute particle form. More preferred are those which show ionic conductivity. Preferable examples of such inorganic oxides in minute particle form include ionic conductive or nonconductive ceramics in minute particle form such as α, β, γ-alumina/ silica, titania, zirconia, magnesia, barium titanate, titanium oxide, and hydrotalcite.
The above-mentioned inorganic oxide in minute particle form preferably has a specific surface area as large as possible in order to increase the amount of the electrolyte-containing solution contained in the above-mentioned ionic composition, thereby increasing the ionic conductivity and the migration degree . The specific surface area is preferably 5 m2/g or more, as determined by the BET method, for example. The specific surface area is more preferably 50 m2/g ormore . Such an inorganic oxide in minute particle form may have any crystal particle diameter as long as the oxide can be mixed with other components in the above-mentioned ionic composition. The lower limit of the size (average crystal particle diameter) is preferably 0.01 μm, and the upper limit thereof is preferably 20 μm. More preferably, the lower limit is 0.01 μm and the upper limit is 2 um.
The above-mentioned inorganic oxide in minute particle formmay have various shapes, for example, spherical, oval, cubic, cuboid, cylindrical, or rod-like shape.
The above-mentioned inorganic oxide in minute particle form is preferably added such that the upper limit of the added amount is 50% by weight relative to 100% by weight of the above-mentioned ionic composition. If the amount is more than 50% by weight, the strength or the ionic conductivity in the above-mentioned ionic composition may be reduced or a film is difficult to form using the ionic composition. The upper limit is more preferably 30% by weight . The lower limit is preferably 0.1% by weight.
The above-mentioned ionic composition may contain various additives in addition to the above-mentioned salts and solvents . The addition of additives has wide-ranging purposes, and examples thereof include improvement in electrical conductivity and in thermal stability, suppression of deterioration of an electrode due to hydration or dissolution, suppression of gas generation, and improvement in withstand voltage and in wettability. Examples of such additives include nitro compounds such as p-nitrophenol, m-nitroacetophenone, and p-nitrobenzoic acid; phosphorus compounds such as dibutyl phosphate, monobutyl phosphate, dioctyl phosphate, monooctyl octylphosphonate, and phosphoric acid; boron acid or boron compounds such as complex compounds of boric acidwithpolyhydric alcohols (ethylene glycol, glycerin, mannitol, polyvinyl alcohol or the like) or polysaccharides; nitroso compounds; urea compounds; arsenic compounds; titanium compounds; silicic compounds; aluminic acid compounds; nitric acid and nitrous acid compounds; benzoic acids such as 2-hydroxy-N-methylbenzoic acid and di (tri) hydroxybenzoic acid; acids such as gluconic acid, bichromic acid, sorbic acid, dicarboxylic acid, EDTA, fluorocarboxylic acid, picric acid, suberic acid, adipic acid, sebacic acid, heteropolyacid (tungstic acid, molybdic acid) , gentisic acid, borodigentisic acid, salicylic acid, N-aminosalicylic acid, borodiprotocatechuic acid, borodipyrocatechol, bamonic acid, bonic acid, borodiresorcinic acid, resorcinic acid, borodiprotocachueric acid, glutamic acid and dithiocabamic acid; esters thereof, amides thereof and salts thereof; silane couplingagents; silicon compounds suchas silica, and aliminosilicate; amine compounds such as triethylamine, and hexamethylenetetramine; L-amino acids; benzol; polyhydric phenol; 8-oxyqiunoline; hydroquinone; N-methylpyrocatechol; . quinoline; sulfur compounds such as thioanisole, thiocresol, and thiobenzoic acid; sorbitol; and L-histidine. One or two or more species of them may be used. The content of the above-mentioned additive is not especially limited. The content is preferably within a range of 0.1 to 20% by weight inl00%byweightof the ionic composition. The content is more preferably within a range of 0.5 to 10% by weight . It is preferable that the above-mentioned ionic composition has an ionic conductivity at 0°C of 0.5 mS/cm or more. If the ionic conductivity is less than 0.5 mS/cm, anionic conductor containing the above-mentioned ionic composition may fail to stably function with the lapse of time while retaining an excellent ionic conductivity . The ionic conductivity is more preferably 2.0 mS/cm or more. The ionic conductivity at -55°C is preferably 1 * 10"7 S/cm or more. If the ionic conductivity is less than 1 x 10"7 S/cm, an electrolytic solution containing the above-mentioned ionic composition may fail to sufficiently stably function with the lapse of time while retaining an excellent ionic conductivity. The ionic conductivity is more preferably 1 * 10~6S/cm or more, and still more preferably 5 x 10"5S/cm or more, and particularly preferably 1 * 10"4S/cm or more. The above-mentioned ionic conductivity can be preferably measuredby complex impedance methods using an impedance analyzer HP4294A (trade name, manufacturedby Toyo Corp . ) , or an impedance analyzer SI 1260 (trade name, manufacturedby Solartron Co . , Ltd. ) , each using SUS electrodes. It is preferable that the above-mentioned ionic composition has a viscosity at 25°C of 300 mP-s or less. If the viscosity is more than 300 mPa-s, the ionic conductivity may be improved insufficiently. The viscosity is more preferably 200 mPa • s or less, and still more preferably 100 mPa • s or less, and most preferably 50 mPa-s or less.
The measurement method of the above-mentioned viscosity is not especially limited. Preferred is a method of measuring a viscosity at 25°C using a model TV-20 cone/plate type viscometer (product of Tokimec Inc.). The present invention is also an ionic composition comprising an ionic compound and having a moisture content of
1000 ppm or less, wherein the ionic compound has an excess acid amount or an excess base amount of less than 0.2 x 10"3 mol/g.
Such an ionic composition also can exhibit excellent basic performances such as electrochemical stability and can exhibit sufficient functional effects of the present invention of being preferably used as a material for ionic conductors of electrochemical devices capable of enduring long-term use.
The above-mentioned moisture content of the ionic composition is preferably 1000 ppm or less. If the moisture content is more than 1000 ppm, the electric stability may be insufficiently improved. The moisture content is more preferably 800 ppm or less, and more preferably 500 ppm or less . The moisture content is more preferably 1 ppm or more and more preferably 3 ppm or more in view of easier moisture control. If the above-mentioned ionic composition contains only the above-mentioned ionic compound, the above-mentioned ionic compound satisfies the above-mentioned moisture content value range . The above-mentioned moisture content is preferably measured by the above-mentioned measurement method.
The above-mentioned ionic compound contained in the ionic composition has an excess acid amount or an excess base amount of less than 0.2 * 10"3 mol/g, and contains an anion and a cation. If the excess acid amount or the excess base amount is more than 0.2 x 10"3 mol/g, as mentioned above, reaction with an active substance of a positive electrode or a negative electrode or deterioration of an electrolyte may be caused if the ionic composition is used as an electrolyte for lithium batteries and the like. Therefore, the functional effects of the present invention of providing an ionic composition which exhibits excellent basic performances such as electrochemical stability and can be preferably used in various applications such as electrochemical devices may be insufficiently exhibited. The excess acid amount or the excess base amount is preferably 0.18
10 mol/g or less
Such an ionic compound preferably contains the above-mentioned dicyanotriazolate anion. The cation is preferably at least one cation selected from the group consisting of lithium ion and cations represented by the above formula ( 1 ) . Lithium ion is more preferable. The preferable embodiments of the present invention include an embodiment in which the above-mentioned ionic compound contains a lithium ion (that is, the above-mentioned ionic compound is lithium dicyanotriazolate) .
The preferable embodiments or the production method and the like in the ionic compound containing such an anion and cation are as mentioned above . The preferable embodiments and the like of the ionic composition containing the ionic compound are preferably the same as those in the above-mentioned ionic composition.
-Use embodiments of the ionic compound and the ionic composition- The ionic compound and the ionic composition of the present invention can exhibit the above-mentioned properties, and therefore can be preferably applied in various applications. Among them, the ionic compound and the ionic composition are particularly preferable as electrolytes constituting electrochemical devices such as batteries having charge/discharge mechanisms, such as primary batteries, lithium (ion) secondary, batteries and fuel batteries; electrolytic solution for electrolytic condensers; electrolytic condensers; electric double layer capacitors; and solar batteries and electrochromic display devices. Thus, the preferable embodiments of the present invention include an electrolyte containing the above-mentioned ionic compound and/or the above-mentioned ionic composition. The preferable embodiments of the present invention also include a battery, an electrolytic solution for electrolytic condensers, an electrolytic condenser, or an electric double layer capacitor, each prepared using the above-mentioned ionic compound and/or the above-mentioned ionic composition. The above-mentioned ionic compound and/or the ionic composition is/are preferably used as an electrolyte, but may be used as materials other then electrolytes. The above-mentioned battery prepared using the ionic compound and/or the anionic composition is preferably a battery having charge and dischargemechanisms such as primarybatteries, lithium (ion) secondary batteries, and fuel batteries. Among them, lithium secondary batteries are particularly preferable. The above-mentioned electrolyte contains the above-mentioned ionic compound and/or the above-mentioned ionic composition, and preferably contains the above-mentioned ionic compound and/or the above-mentioned ionic composition, and a matrix material. Thus, the preferable embodiments of the present invention include such an electrolyte containing the above-mentioned ionic compound and/or the above-mentioned ionic composition, and a matrix material.
The above-mentioned electrolyte means a material for electrolytic solutions or a material for electrolytes. Such an electrolyte can preferably used in ionic conductors of electrochemical devices as (1) a solvent constituting electrolytic solutions and/or (2) a material for electrolytes (material for ionic conductors), and (3) a material for solid electrolytes (material for electrolytes) . For example, in the application of (1), the above-mentioned electrolyte containing the ionic compound and/or the ionic composition constitutes an electrolytic solution (or a solid electrolyte) , together with a substance showing ionic conductivity in the solvent. In the application of (2), the above-mentioned electrolyte containing the ionic compound and/or the ionic composition is contained in the solvent to constitute a material for electrolytes. In the application of (3) , the above-mentioned electrolyte containing the ionic compound and/or the ionic composition serves as a solid electrolyte as it is or after another component is contained in the electrolyte.
The above-mentioned matrix material is preferably an electrolyte essentially containing an organic solvent.
As such an organic solvent, the above-mentioned organic solvents are preferable. If the above-mentioned electrolyte constitutes an electrochemical device, a preferred form of the electrochemical device includes, as basic constituent elements, an ionic conductor, a negative electrode, a positive electrode, current collectors, separators and a container. A mixture of an electrolyte with an organic solvent or a polymer is preferably used as the above-mentioned ionic conductor. This ionic conductor is generally called an "electrolytic solution" if an organic solvent is used and called an "electrolyte" if apolymer solidelectrolyte is used. Polymer solid electrolytes containing anorganic solvent asaplasticizer are included in the polymer solid electrolyte. The above-mentioned electrolyte containing the ionic compound and/or the ionic composition can be preferably used as a substitute for the electrolyte or the organic solvent in the electrolytic solution in such an ionic conductor, and the electrolyte can be preferably used as a polymer solid electrolyte. In an electrochemical device prepared using such an electrolyte as a material for the ionic conductor, at least one of the materials for the ionic conductor is constituted of the above-mentioned electrolyte. Among them, it is preferable that the electrolyte is used as the substitute for the organic solvent or as the polymer solid electrolyte in the electrolytic solution.
The above-mentioned organic solvent may be an aprotic solvent capable of dissolving the above-mentioned electrolyte containing the compound and/or the ionic composition, and the above-mentioned organic solvents are preferable as such an organic solvent. However, if two or more solvents are used as a mixed solvent or the electrolyte comprises Li ion, the electrolytic solution is preferably prepared by dissolving the electrolyte in a mixed solvent composed of an aprotic solvent having a permittivity of 20 or more and an aprotic solvent having a permittivity of 10 or less among such organic solvents. Particularly if a lithium salt is used as the electrolyte, the solution has a low solubility in an aprotic solvent having a permittivity of 10 or less, such as diethyl ether or dimethyl carbonate, and therefore a sufficient ionic conductivity can not be obtainedby the solution singly . Conversely, the solution has a high solubility in an aprotic solvent having a permittivity of 20 or more, but also has a high viscosity. Therefore, the ions are difficult to migrate and also in this case, a sufficient ionic conductivity can not be obtained. If these solvents are mixed together, appropriate solubility and migration degree can be secured and sufficient ionic conductivity can be obtained.
As the polymer which dissolves the abov.e-mentioned electrolyte, one or two or more of the above-mentioned polymers can be preferably used. Among them, preferred are polymers or copolymers having polyethlene oxide as a main chain or a side chain, homopolymers or copolymers of polyvinylidene fluoride, methacrylate polymer, and polyacrylonitrile . If a plasticizer is added to these polymers, the above-mentioned aprotic organic solvent may be used.
The electrolyte concentration in the above-mentioned ionic conductor is preferably 0.01 mole/dm3 or more and a saturation concentration or less. The concentration of less than 0.01 mole/dm3 is undesirable, because the ionic conductivity is low. The concentration is more preferably 0.1 mole/dm3 or more and 1.5 mole/dm3 or less.
Lithium metal or an alloy of lithium and other metals is preferably used as the material for the above-mentioned negative electrode, in lithium batteries. In lithium ion batteries, preferred are polymers, organic materials, carbon obtained by baking pitch or the like, natural graphite, and materials which are prepared by phenomenon called intercalation, such as metal-oxide. In electric double layer capacitors, preferred are active carbons, porous metal oxides, porous metals, and conductive polymers.
As the material for the above-mentionedpositive electrode, in lithium batteries and lithium ion batteries, preferred are lithium-containing oxides such as LiCoO2, LiNiO2/ LiMnO2 and LiMn2O4; oxides such as TiO2, V2O5 and MoO3; sulfides such as TiS2 and FeS; and conductive polymers such as polyacetylene, polyparaphenylene, polyaniline and polypyrrole. In electric double layer capacitors, activate carbons, porous metal oxides, porous metals and conductive polymers are preferred. (1) a lithium secondary battery, (2) an electrolytic condenser and (3) an electric double layer capacitor, each prepared using the ionic compound and/or the ionic composition of the present invention are mentioned below. (1) Lithium secondary battery Alithium secondarybattery is constitutedof the following basic constituent elements: a positive electrode, a negative electrode, separators occurring between the positive and negative electrodes, and an ionic conductor containing an electrolyte containing the above-mentioned ionic compound and/or the above-mentioned ionic composition. In this case, the electrolyte containing the above-mentioned ionic compound and/or the above-mentioned ionic composition contains a lithium salt as a substance showing ionic conductivity. Preferred as such a lithium secondary battery is a nonaqueous electrolyte lithium secondary battery, which is other than an aqueous electrolyte lithium secondary battery. Fig. 1 shows a cross-sectional view schematically showing one embodiment of such a lithium secondary battery. In this lithium secondary battery, coke is used as a negative electrode active substance mentioned below and a Co-containing compound is used a positive electrode active substance mentioned below. In such a lithium secondary battery, during charging, the reaction C6Li → 6C + Li + e occurs on the negative electrode, the electron (e-) generated on the negative electrode surface migrates through the electrolytic solution to the positive electrode surface in the manner of ionic conduction. On the positive electrode surface, the reaction CoO2 + Li + e- -.LiCoO2 occurs and an electric current flows from the negative electrode to the positive electrode. During discharging, reverse reactions as compared with those during charging occur, and an electric current flows from the positive electrode to the negative electrode. In this manner, electricity can be stored or supplied by such ion-involving chemical reactions.
The above-mentioned negative electrode is preferably produced by applying a negative electrode mixture containing a negative electrode active substance, a conductive agent for negative electrodes, a binder for negative electrodes, and the like to the surface of a current collector for negative electors . The negative electrode mixture may contain various additives in addition to the conductive agent and the binder.
Metallic lithium and materials capable of occluding and releasing lithium ions are preferred as the above-mentioned negative electrode active substance . Preferred examples of the above-mentioned materials capable of occluding and releasing lithium ions include metallic lithium; pyrolytic carbons; cokes such as pitch coke, needle coke and petroleum coke; graphite; glassy carbons; organic polymer-derived baking products which are produced by baking phenolic resins, furan resins and the like at an appropriate temperature to convert them into carbon; carbon fibers; carbon materials such as active carbon; polymers such as polyacetylene, polypyrrole and polyacene; lithium-containing transition metal oxides or transition metal sulfides, such as Li4Z3Ti5Z3O4 and TiS2; metals capable of alloying with alkali metals, such as Al, Pb, Sn, Bi and Si; cubic intermetallic compounds capable of intercalating alkali metals, such as AlSb, Mg2Si and NiSi2, and lithium nitrogen compounds such as Li3-fGfN (G: transition metal) . One or two or more of them may be used. Among them, metallic lithium and carbonaceous materials, which can occlude and release alkali metal ions, are more preferred.
The above-mentioned conductive agent for negative electrodes is an electron conductive material. Preferred examples thereof include graphites, for example, natural graphites such as scaly graphite, and artificial graphites; carbon blacks such as acetylene black, Ketjen black, channel black, furnace black, lamp black and thermal black; conductive fibers such as carbon fibers and metal fibers; metals such as fluoride carbon, copper, and nickel, in powder form; and organic conductive materials such as polyphenylene derivatives. One or two or more species of themmay be used. Among them, artificial graphite, acetylene black and carbon fibers are more preferred. The use amount of the conductive agent for negative electrodes is preferably 1 to 50 parts by weight, and more preferably 1 to 30 parts by weight relative to 100 parts by weight of the negative electrode active substance. The negative electrode active substance has electric conductivity, and therefore such a conductive agent for negative electrodes is not necessarily used.
The above-mentioned binder for negative electrodes may be either a thermoplastic resin or a thermosetting resin.
Preferred examples of such a binder for negative electrodes include polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubbers, tetrafluoroethylene-hexafluoropropylene copolymers, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers, vinylidene fluoride-hexafluoropropylene copolymers, vinylidene fluoride-chlorotrifluoroethylene copolymers, ethylene-tetrafluoroethylene copolymers, polychlorotrifluoroethylene, vinylidene fluoride-pentafluoropropylene copolymers, propylene-tetrafluoroethylene copolymers, ethylene-chlorotrifluoroethylene copolymers, vinylidene fluoride-hexafluoropropylene- tetrafluoroethylene copolymers, vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene copolymers, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, ethylene-methyl acrylate copolymers, ethylene-methyl methacrylate copolymers; polyamides, polyurethanes, polyimides, polyvinylpyrrolidone, and copolymers thereof . One or two or more of them may be used. Among them, more preferred are styrene-butadiene rubbers, polyvinylidene fluoride, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, ethylene-methyl acrylate copolymers, ethylene-methyl methacrylate copolymers; polyamides, polyurethanes, polyimides polyvinylpyrrolidone, and copolymers thereof.
The above-mentioned current collector for negative electrodes is an electron conductor not causing any chemical change within the battery. Preferred examples thereof include stainless steel, nickel, copper, titanium, carbon, conductive resins, and copper or stainless steel having a surface on which carbon, nickel, titaniumor the like is adhered or coated. Among them, copper and copper-containing alloys are more preferred. One or two or more species of them may be used. The surface of these current collectors for negative electrodes may be oxidized and then used. In addition, it is preferable that the surface of the current collector is provided with projections and depressions . The current collector for negative electrodes preferably has a form of a foil, film, sheet, net, punched body, lath, porous body, foamed body, or molded fiber group, for instance. The current collector preferably has a thickness of 1 to 500 μm.
The above-mentioned positive electrode is preferably produced by applying a positive electrode mixture containing a positive electrode active substance, a conductive agent for positive electrodes, a binder for positive electrodes and the like to the surface of a current collector for positive electrodes . The positive electrode mixture may contain various additives in addition to the conductor and the binder. Preferred as the above-mentioned positive electrode active substance are metallic Li, LixCoO2, LixNiO2, LixMnO2, LixCoyNii-yθ2, LixCoyJi-y0z, LixNii-yJyOz, LixMn2O4, LixMn2.yJyθ4 ; and lithium-free oxides such as MnO2, Vq0h and Crg0h (g and h each being an integer of 1 or more) . One or two or more species of them may be used. The above-mentioned "J" represents at least one element selected from the group consisting of Na, Mg, Sc, Y, Mn, Fe, Co, Ni, Cu, Zn, Al, Cr, Pb, Sb and B. The "x" satisfies 0 <=x<= 1.2, and the "y" satisfies 0<=y<=0.9, and the "z" satisfies 2.0 <=z<= 2.3. The "x" varies as a result of charge or discharge of the battery. The following compounds may be used as the positive electrode active substance: transition metal chalcogenides; vanadium oxides or niobium oxides, which may contain lithium; conjugated polymer-based organic conductive substances; and Chevrel phase compounds. The positive active substance particles preferably have an average particle diameter of 1 to 30 μm.
The above-mentioned conductive agent for positive electrodes is an electron-conductive material not causing any chemical change at charge and discharge potentials for the positive electrode active substance used. Preferred examples thereof include the same materials as in the above-mentioned conductive agent for negative electrodes; metals such as aluminum and silver, in powder form; conductive whiskers such as zinc oxide and potassium titanate; and conductive metal oxides such as titanium oxide. One or two or more species of them may be used. Among these, artificial graphite, acetylene black and nickel in powder form are more preferred. The use amount of the conductive agent for positive electrodes is preferably 1 to 50 parts by weight, and more preferably 1 to 30 parts by weight relative to 100 parts by weight of the positive electrode active substance. If carbon black or graphite is used, the use amount is preferably 2 to 15 parts by weight relative to 100 parts by weight of the positive electrode active substance. The above-mentioned binder for positive electrodes may be either a thermoplastic resin or a thermosetting resin. Preferred examples thereof include: those mentioned above in the binder for negative electrodes, other than styrene-butadiene rubbers; and tetrafluoroethylene-hexafluoroethylene copolymers. One or two or more species of them may be used. Among them, polyvinylidene fluoride and polytetrafluoroethylene are more preferred.
The above-mentioned current collector for positive electrodes is an electron conductor not causing any chemical change at charge and discharge potentials for the positive electrode active substance used. Preferred examples thereof include stainless steel, aluminum, titanium, carbon, conductive resins, and aluminum or stainless steel having a surface on which carbon, nickel, and the like is adhered or coated. One or two or more species of them may be used. Among them, aluminum and aluminum-containing alloys are preferred. The surface of these current collectors for positive electrodes may be oxidized and then used. In addition, it is preferable that the surface of the current collector is provided with projections and depressions. The current collector for positive electrodes has the same form and thickness as mentioned above in the current collector for negative electrodes.
The above-mentioned separators each is preferably made of a microporous insulating thin membrane showing a high ion permeability and a predetermined mechanical strength if an electrolytic solution is used as the ionic conductor. It is also preferable that the separators have a function of closing the pores at temperatures exceeding a certain temperature and thereby increasing the resistance . The following materials are preferablyused as amaterial for the separators in view of organic solvent resistance and hydrophobicity: porous synthetic resin films made of a polyolefin polymer such as polyethylene or polypropylene; woven or nonwoven fabrics made of an organic material such as polypropylene or fluorinated polyolefin; and woven or nonwoven fabrics made of a glass fiber or an inorganic material. The separator preferably has a pore diameter within a range such that it is impermeable to the positive electrode active substance, the negative electrode active substance, the binders and the conductive agents separated from the electrodes . The separator preferably has a pore diameter of 0.01 to 1 urn. The separator preferably has a thickness of 10 to 300 μm. The void ratio is preferably 30 to 80%.
The separator surface is preferably modified in advance by corona discharge treatment, plasma discharge treatment, or wet treatment using a surfactant so that the hydrophobicity may be reduced. Such treatment can improve the wettability of the separator surface and the pore inside, which makes it possible to prevent, to the utmost, the internal resistance of the battery from increasing. In the constitution of the above-mentioned lithium secondary battery, an electrolytic solution-carrying polymer material gel may be contained in the positive electrode mixture or the negative electrode mixture, or a porous separator made of an electrolytic solution-carrying polymer material may be integratedwith the positive electrode or the negative electrode. The above-mentioned polymer material is a material capable of holding the electrolytic solution and preferably is a vinylidene fluoride-hexafluoropropylene copolymer, for instance.
The above-mentioned lithium secondary battery has a coin form, button form, sheet form, layer-built form, cylindrical form, flat form, rectangular form, large form for use in an electric vehicle, and the like. (2) Electrolytic condenser
An electrolytic condenser is constituted of the following fundamental constituent elements : a condenser element including an anode foil, a cathode foil, an electrolytic paper sheet sandwiched between the anode foil and cathode foil and serving as a separator, and lead wires; an ionic conductor containing an electrolyte containing the above-mentioned ionic compound and/or the above-mentioned ionic composition; an exterior case of a cylinder shape with a bottom; and a sealing body for sealing the exterior case. Fig. 2 (a) is a perspective view showing one embodiment of such a condenser element. The electrolytic condenser of the present invention is obtained by: impregnating a condenser element with an electrolytic solution containing the above-mentioned ionic composition, which serves as an ionic conductor; accommodating the condenser element into an exterior case of a cylinder shape with a bottom; packaging a sealing body in an opening part of the exterior case and, at the same time, subjecting an end part of the exterior case to embossing procession; and thereby sealing the exterior case. Preferred examples of such an electrolytic condenser include an aluminum electrolytic condenser, a tantalate electrolytic condenser, and a niobium electrolytic condenser. Fig. 2 (b) is a cross-sectional view schematically showing one embodiment of such an aluminum electrolytic condenser. In a preferred form of such an aluminum electrolytic condenser, a thin oxide (aluminum oxide) film to serve as a dielectric is formed, by electrolytic anodic oxidation, on the aluminum foil surface roughened by finely provided with projections and depressions by electrolytic etching.
As the above-mentioned anode foil, an anode foil obtained by: chemically or electrochemically etching an aluminum foil having a purity of 99% or more in an acidic solution to perform plane extending treatment; performing formation treatment in an aqueous solution of ammonium borate, ammonium phosphate, ammonium adipate or the like; and forming an anode oxidized film layer on the surface.
As the above-mentioned cathode foil, the following aluminum foil can be used. The aluminum foil is prepared by forming, on a part or all of the foil surface, a film made of one or more species of metal nitride selected from titanium nitride, zirconiumnitride, tantalumnitride andniobiumnitride, and/or, one or more species of metal selected from titanium, zirconium, tantalum and niobium.
The above-mentioned film can be formed by a deposition method, a plating method, a coating method and the like, for example. As the part on which the film is formed, the whole surface of the cathode foil may be covered. As necessary, a part of the cathode foil, for example, only one side of the cathode foil may be covered with a metal nitride or a metal.
Each of the above-mentioned lead wires is preferably constituted of a connecting part making contact with the anode foil and the cathode, foil; a round bar part; and an external connecting part. Such lead wires are electrically connected to the anode foil and the cathode foil by means of such as a stitch and ultrasound welding, at the connecting parts, respectively. The connecting part and the round bar part in the lead wire are preferably made of high purity aluminum. The external connecting part is preferably made of a copper-plated iron steel wire which has been subjected to solder plating. On a part or all of the surface of the round bar and the connecting part with the cathode foil, an aluminum oxide layer formed by anode oxidizing treatment with an aqueous solution of ammonium borate, an aqueous solution of ammonium phosphate, or an aqueous solution of ammonium adipate may be formed. An insulating layer such as a ceramic coating layer made of Al2O3, SiO2 and ZrO2 or the like may be also formed on a part or all of the surface of the round bar part and the connecting part with the cathode foil . The exterior case is preferably made of aluminum.
The sealing body is preferably provided with through holes from which the lead wires lead out, and made of an elastic rubber such as butyl rubber. A rubber elastic body produced by the followingprocedures maybe used as suchbutyl rubber, for example . The rubber elastic body is produced by: adding a reinforcing agent (carbon black or the like) , a bulking agent (clay, talc, calcium carbonate or the like) , a procession assistance (stearic acid, zinc oxide or the like) , a vulcanizing agent or the like to crude rubber made of an isobutylene-isoprene copolymer; kneading the mixture; and rolling and molding the resulting mixture . Examples of the vulcanizing agent include alkylphenol formalin resins; peroxides (dicumyl peroxide, 1, 1-di- (t-butylperoxy) -3, 3, 5- trimethylcyclohexane, 2, 5-dimethyl-2, 5-di- (t-butylperoxy) hexane or the like); quinoides (p-quinonedioxime, p, p' -dibenzoylquinonedioxime or the like) ; and sulfur. It is more preferable that the surface of the sealing body is coated with a resin such as teflon (registered trademark), or a plate of bakelite or the like is applied thereto, and thereby permeability of solvent steam is reduced.
As the above-mentioned separator, paper such as manila paper and kraft paper is usually used, and a non-woven fabric of a glass fiber, polypropylene/ polyethylene or the like may be used. The above-mentioned electrolytic condenser may be of a hermetic sealing structure, or of a structure in which the condenser is sealed in a resin case (described, for example, in Japan Kokai Publication No. Hei-08-148384) . In the case of an aluminum electrolytic condenser having a rubber sealing structure, gas is permeated through the rubber to some extent. Therefore, there is apossibility that the solvent is volatilized from the interior of the condenser into the air under high temperature environment, or moisture is mixed into the interior of the condenser from the air under high temperature and high humidity environment. Under such a severe environment, the capacitor causes unpreferable changes in properties, such as reduction in electrostatic capacity. In contrast, in the condenser of a hermetic sealing structure or a structure in which the condenser is sealed into a resin case, a permeation amount of gas is extremely small . Therefore, such a condenser exhibits stable properties also under such a severe environment. (3) Electric double layer capacitor
An electric double layer capacitor is constituted of the following fundamental constituent elements: a negative electrode, a positive electrode, and an ionic conductor containing an electrolyte containing the above-mentioned ionic compound and/or the above-mentioned ionic composition. In a preferred form, an electrolytic solution, which is the ionic conductor, is contained in an electrode element composed of the positive electrode and the negative electrode opposed to each other. Fig. 3 shows a sectional view schematically showing one embodiment of such an electric double layer capacitor and an enlargement view showing the electrode surface.
Each of the above-mentioned positive electrode and the above-mentioned negative electrode is a polarizable electrode. Each of the electrodes is constituted of: active carbon serving as an electrode active substance, such as active carbon fibers, a molding of active carbon particles, or active carbon particles; a conductive agent; and a binder substance, and is preferably used in such a molded form as a thin coat film, a sheet or a plate. In the electric double layer capacitor having such a configuration, electric charge is stored in the electric double layer formed at the interfaces between the polarizable electrodes and the electrolytic solution as a result of physical adsorption and desorption of ions, as shown in the enlargement given in Fig. 3.
The above-mentioned active carbon preferably has an average pore diameter of 2.5 nm or less. This average pore diameter of the active carbon is preferablymeasuredby a nitrogen adsorption BET method. The specific surface area of the active carbon depends on the electrostatic capacity of the carbonaceous species per unit area (F/m2) or on decrease in bulk density due to increase in specific surface area. However, the specific surface area determined by the nitrogen adsorption BET method is preferably 500 to 2500 m2/g, and more preferably 1000 to 2000
The above-mentioned active carbon is preferably produced by the following activation method. The activation method includes carbonizing the following raw material and then activating the carbonated substance. Examples of the raw materials include : plant materials such as wood, sawdust, coconut shells or pulping waste liquor; fossil fuel materials, such as coal, heavy petroleum oil, or pyrolyzate derived therefrom, e.g. coal pitch, petroleum pitch, petroleum coke, carbon aerogel, mesophase carbon, tar pitch fiber; synthetic polymer, phenol resin, furan resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyimide resin, polyamide resin, ion exchange resin, liquid crystal polymers; a plastic waste; and a waste tire . The above-mentioned activation method includes the following methods (1) and (2) : (1) gas activation method in which the carbonized raw material is brought into contact with steam, carbon oxide gas, oxygen, or other oxidizing gas and thereby reactedwith each other at high temperatures; and (2) the chemical activation method in which the carbonized raw material is homogeneously impregnated with zinc chloride, phosphoric acid, sodium phosphate, calcium chloride, potassium sulfide, potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, sodium sulfate, potassium sulfate, calcium carbonate, boric acid, or nitric acid, and then the mixture is heated in an inert gas atmosphere to give active carbon as a result of dehydration and oxidation reactions in the presence of a chemical. Either of the methods may be used.
It is preferable that the active carbon obtained by the above-mentioned activation method is thermally treated in an inert gas atmosphere, such as nitrogen, argon, helium or xenon at preferably 500 to 2500°C and more preferably 700 to 15000C, thereby to eliminate unnecessary surface functional groups and/or develop the crystallinity of the carbon for increasing the electronic conductivity. The active carbon may be in a crushed, granulated, granular, fibrous, felt-like, woven or sheet form, for instance. If the active carbon is in a granular shape, it preferably has an average grain diameter of 30 um or less from the viewpoint of improvement in the electrode bulk density and reduction in the internal resistance. Carbonaceous materials having such a high specific surface area as mentioned above may be used as the electrode active substance, in addition to the active carbons . For example, carbon nanotubes or diamond produced by plasma CVD also may be used. Preferred examples of the above-mentioned conductive agent include carbon black such as acetylene black and Ketjen black, natural graphite, thermally expansible graphite, carbon fibers, ruthenium oxide, titanium oxide, aluminum, nickel or like metal fibers. One or two or more species of them may be used. Among them, acetylene black and Ketjen black are more preferred since they can effectively improve the conductivity in small amounts. The mixing amount of the conductive agent varies depending on the bulk density of the active carbon and the like, but preferably is 5 to 50% by weight, andmore preferably 10 to 30% by weight, relative to 100% by weight of the active carbon.
Preferred examples of the above-mentioned binder substance include polytetrafluoroethylene, polyvinylidene fluoride, carboxymethylcellulose, fluoroolefin copolymer crosslinked polymers, polyvinyl alcohol, polyacrylic acid, polyimides, petroleuinpitch, coalpitch, and phenol resins . One or two or more species of them may be used. The mixing amount of the binder substance varies depending on the active carbon species and the form thereof, but is preferably 0.5 to 30% by weight, and more preferably 2 to 30% by weight, relative to 100% by weight of the active carbon.
Each of the above-mentioned positive electrode and the above-mentioned negative electrode is preferably formed by the following methods (1) to (3) : (1) a method in which polytetrafluoroethylene is added and mixed with a mixture of the active carbon and acetylene black and the resulting mixture is molded by pressing; (2) a method in which the active carbon and the binder substance such as pitch, tar, and phenolic resin and the mixture is molded, and the molding was thermally treated in an inert atmosphere to give a sintered body; and (3) a method in which the active carbon and the binder substance, or only the active carbon, is sintered to form an electrode . If an active carbon fiber cloth obtained by activation treatment of a carbon fiber cloth is used, the cloth as it is may be used as an electrode without using any binder substances. In the above-mentioned electric double layer capacitor, the polarizable electrodes are preferably prevented from contacting or short-circuiting with each other by inserting a separator between the polarizable electrodes or by opposing the polarizable electrodes with a space between them using a holding means, for instance. Suited for use as the separator are porous thin films not causing any chemical reactions with the molten salt and the like in the temperature range for use. Suitable separator materials are paper, polypropylene, polyethylene and glass fibers, and the like.
The form of the above-mentioned electric double layer capacitor includes a coin type, wound type, rectangular type, aluminum laminate type and the like. Any form may be employed.
The electrochemical devices such as the lithium secondary battery, the electrolytic condenser, and the electric double layer capacitor, each prepared using the above-mentioned ionic compound and/or the above-mentioned ionic composition, are preferably used in various applications such as portable information terminals, portable electronic apparatuses, small-sized household electric power storages, motorcycles, electric vehicles, and hybrid electric vehicles.
Use embodiments in which the lithium dicyanotriazolate is used as the above-mentioned ionic compound are mentionedbelow in more detail. It is preferable that the above-mentioned lithium dicyanotriazolate is contained in an electrolyte for lithium batteries. The combinations of an electrolyte, a separator, a positive electrode, a negative electrode, and the like may be appropriately determined depending on functions or configurations of lithium batteries to be used, such as primary batteries, lithium ion secondary batteries and lithium polymer secondary batteries.
For example, as the electrolyte, an electrolyte having ionic conductivity suitable for primary batteries, lithium ion secondary batteries, and lithium polymer secondary batteries can be produced by adding LiDCTA to an organic solvent and/or a polyether polymer or an acrylic polymer. In this case, separators may be used if necessary, except for the cases where the polymer-containing electrolyte provides sufficient film strength.
Examples of the base material of the above-mentioned polymer electrolyte include polyether copolymers such as polyethylene oxide andpolypropylene oxide . Polyethylene oxide is preferable. The proportion of LiDCTA is preferably 10 to 35% by weight in the above-mentioned polymer electrolyte. If the proportion is less than 10% by weight, a sufficient conductivity may not be obtained. If the proportion is more than 25% by weight, the LiDCTA may be insufficiently dissolved. The proportion is preferably 15 to 30% by weight. The above-mentioned polymer electrolyte preferably contains no solvents. However, the electrolyte may contain 1 to 99% by weight of a solvent in 100% by weight of the electrolyte material, if the polymer electrolyte maintains sufficient film strength. If the solvent is less than 1% by weight, the ionic conductivity is insufficiently improved. If the solvent is more than 99% by weight, the stability may be insufficiently improved due to volatilization of the solvent. The lower limit is preferably 1.5% by weight, and more preferably 20% by weight, and still more preferably 50% by weight. The upper limit is preferably 85% by weight, and more preferably 75% by weight, and still more preferably 65% by weight. It is preferable that the solvent accounts for 50 to 85% by weight in the electrolyte material .
The above-mentioned solvent is a solvent capable of improving the ionic conductivity. Organic solvents are preferable, for example.
The organic solvents mentioned above are preferably used as the above-mentioned organic solvent. Among them, carbonic acid esters, aliphatic esters, and ethers are more preferable, and carbonates are still more preferable. The above-mentioned solvent may contain an ionic liquid. The ionic liquid is a compound composed of a cation and an anion. One or two or more species of the ionic liquid may be used. The above-mentioned ionic liquid is preferably a liquid having fluidity and a certain specified volume at 40°C. Specifically, it is preferable the ionic liquid is a liquid having a viscosity of 500 mPa-s or less at 400C. The viscosity is more preferably 200 mPa-s or less, and still more preferably 100 mPa-s. Specific examples of such an ionic liquid include l-ethyl-3-methylimidazolium trifluoromethane sulfonimide, l-ethyl-3-methylimidazolium dicyanoamide, l-ethyl-3-methylimidazolium tricyanomethide, diethyl dimethoxy trifluoromethane sulfonimide, diethyl dimethoxy dicyanoamide, diethyl dimethoxy tricyanomethide, 1-methyl-l-butyl trifluoromethane sulfonimide, 1-methyl-1-butyldicyanoamide, and 1-methyl-l-butyltricyanomethide .
The above-mentioned electrolyte containing the lithium dicyanotriazolate is preferably used in a lithium battery. The above-mentioned lithium battery is preferably constituted of the following fundamental constituent elements: apositive electrode, a negative electrode, separators occurring between the positive and negative electrodes, and the above-mentioned electrolyte containing lithium dicyanotriazolate. Preferred as such a lithium secondary battery is a nonaqueous electrolyte lithium secondary battery, which is other than an aqueous electrolyte lithium secondary battery. In a lithium secondary battery containing lithium metal as the negative electrode active substance and containing V2O5 as the positive electrode active substance, during discharging, the reaction Li → Li+ + e~ occurs on the negative electrode, and the lithium ion (Li+) generated on the negative electrode surface migrates through the electrolyte in the manner of ionic conduction, and the electron (e~) migrates through the external circuit to the positive electrode surface in the manner of electron conduction. On the positive electrode surface, the reaction V2O5 + Li + e"→ LiV2O5 occurs and an electric current flows from the negative electrode to the positive electrode. During charging, reverse reactions as compared with those during discharging occur, and an electric current flows from the negative electrode to the positive electrode. In this manner, electricity can be stored or supplied by such ion-involving chemical reactions.
Metallic lithium is preferably used as the above-mentioned negative electrode in lithium primary batteries and lithium polymer secondary batteries. In lithium ion secondary batteries, the above-mentioned negative electrode is preferably produced by applying a negative electrode mixture containing a negative electrode active substance, a conductive agent for negative electrodes, a binder for negative electrodes, and the like to the surface of a current collector for negative electrodes.
Other specific embodiments (specific embodiments of the positive electrode, the negative electrode, and the like) in the above-mentioned lithium batteries are as mentioned above.
As mentioned above, the above-mentioned lithium dicyanotriazolate has a high ionic conductivity and causes no corrosion to the electrodes and the like. In addition, such lithium dicyanotriazolate is stable over time. Therefore, an ionic composition containing such an ionic compound is excellent in charge and discharge properties, and therefore permits practical use of electrochemical devices such as lithium batteries having long-term reliability. In addition, electrochemical devices such as lithium secondary batteries, prepared using the above-mentioned polymer electrolyte containing lithium dicyanotriazolate, can be preferably used in various applications such as portable information terminals and portable electronic apparatuses.
BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in more detail below with reference to Examples, but the present invention is not limited to the following Examples. The term "%" represents "% by weight" unless otherwise specified.
Example 1
"Step 1"
Synthesis of l-ethyl-3-methylimidazolium bromide
Into a flask equipped with a thermometer, a nitrogen gas inlet tube, a reflux condenser tube, a stirrer, and a dropping funnel, methylimidazole 82 g (1.0 mol) and 2-butanone
(hereinafter, described as MEK) 400 g were charged. While the mixture was maintained at 50°C under nitrogen flow, ethyl bromide
163.5 g (1.5 mol) was added dropwise into the mixture over 2 hours. Then, the mixture was maintained at 80°C for 2 hours and then the reaction was completed. Then, the reaction liquid was filtered to obtain l-ethyl-3-methylimidazolium bromide (hereinafter, described as EMImBr) whichwas a slight brown-white crystal. Then, this crystal was washed with MEK two times in a glove box, the inside of which was substituted with nitrogen, to obtain white EMImBr 172g (yield of 90%) .
"Step 2"
Synthesis of 4, 5-dicyanotriazolate silver Into a flask equipped with a thermometer, a nitrogen gas inlet tube, a reflux condenser tube, a stirrer, and a dropping funnel, dicyanomaleonitrile (hereinafter, described as DAMN) 216 g (2.0 mol), sulfuric acid 98 g, and ion exchange water 400 g were charged. While the mixture was maintained at 0°C under nitrogen flow, sodium nitrile 138 g (2.0 mol) and water 400 g were added dropwise into the mixture over 1 hour.
Then, the mixture was maintained at 25°C for 1 hour and then the reaction was completed.
Then, the reaction solution was subjected to extraction step using diethyl ether and ion exchange water to obtain a brown solid. This obtained solid was sublimed at 80°C and at 30 Pa to obtain white 4, 5-dicyanotriazole (hereinafter, described as HDCTA) 16O g.
Then, theHDCTA119g (l.Omol) was dissolved in ion exchange water 500 g, and thereto a 30% by weight aqueous solution of sodium hydroxide 40 g was added under cooling. Thereby, an aqueous solution of sodium dicyanotriazolate was obtained.
Then, into a 2L-separable flask equippedwith a thermometer, a nitrogen gas inlet tube, a reflux condenser tube, a stirrer, and a dropping funnel, the above-mentioned aqueous solution of sodium dicyanotriazolate was charged and stirredat 25°C. Then, silver nitrate 169 g (1.0 mol) was dissolved in ion exchange water 360 g. This aqueous solution was added dropwise into the flask over 1 hour . During the dropwise addition, the temperature in the system was maintained at 400C or less. After completion of the dropwise addition, the reaction mixture was stirred for three more hours, and the resulting product was subjected to suction filtration. Thereby, a cake-like silverish white substance was obtained. This cake-like substance was dispersed into ion exchange water and then subjected to suction filtration. This operation was repeated three times to obtain cake-like silver dicyanotriazolate (hereinafter, described as AgDCTA) . This AgDCTA has a solids content of 85%.
"Step 3"
Synthesis of l-ethyl-3-methylimidazolium dicyanotriazolate
Into a flask equipped with a thermometer, a nitrogen gas inlet tube, a reflux condenser tube, and a stirrer, the above-mentioned cake-like AgDCTA 120 g (0.45 mol) and ion exchange water 500 g were charged and dispersed at room temperatures. Then, EMImBr 57.3 g (0.30 mol) was dissolved in ion exchange water 200 g and thereinto the above-mentioned AgDCTA-dispersed aqueous solution was added dropwise over 2 hours . During the dropwise addition, the temperature in the system was maintained at 30°C or less. After completion of the dropwise addition, the reaction mixture was stirred for 24 hours at room temperatures. Then, the reacted product was subjected to suction filtration (filter: membrane cellulosemixed ester, pore systemθ.2μm) to remove precipitates therefrom. Then, volatile contents were removed from the filtrate using a rotating evaporator at 50°C and at 10 to 200 mm Hg. Then, the obtained substance was dried at 60 °C under reduced pressure for 3 days to obtain l-ethyl-3-methylimidazolium dicyanotriazolate (hereinafter, abbreviated to EMImDCTA) (65 g, yield of 95%) . This l-ethyl-3-methylimidazolium dicyanotriazolate had a moisture content of 50 ppm, an excess acid amount of 0.05 * 10'3 mol/g, a content of an amidated product of 1.4%. Fig. 4 shows 1H-NMR of the obtained EMImDCTA. Fig. 5 shows 13C-NMR of the obtained EMImDCTA. The measurements were performed under the following conditions, respectively. This EMImDCTA was a buff yellow solid and had a thermal decomposition temperature in nitrogen of 218°C. A mixture of this EMImDCTA with propylene carbonate (hereinafter, abbreviated to PC) 2 mol/kg had an ionic conductivity at 25°C of 3.0 * 10"2S/cm.
(Measurement conditions in Fig. 4)
Standard 1H measurement
Solvent: DMSO
Temperature: room temperature Device: GEMINI-200BB gemini2000 Pulse sequence:
Relaxation delay: 1.254 seconds Pulse: 45.4 degree pulse Incorporation time: 2.741 seconds Spectral range: 3000.3 Hz
The number of times of integration: 16 times
Observation Hl, 199.9329029MHz
Data processing
The number of data points 32768 Measurement time 1 minute (Measurement conditions in Fig. 5)
13C measurement
Solvent: DMSO Temperature: Room temperature
Device: GEMINI-200BB gemini2000
Pulse sequence:
Relaxation delay: 1.000 seconds
Pulse: 44.6 degree pulse Incorporation time: 1.498 seconds
Spectral range: 12500.0 Hz
The number of times of integration: 13712 times
Observation C13, 50.2732453MHz decouple Hl, 199.9339080MHz power 4IdB continuously on
WALTZ-I 6 modulated
Data processing
Line breadth: 1.0Hz The number of data point 65536
Measurement time 9.5 hours
Example 2
Into a flask equipped with a thermometer, a nitrogen gas inlet tube, a reflux condenser tube, a stirrer, and a dropping funnel, the HDCTA 35.7 g (0.3 mol) obtained in the step 2 in Example 1 was dissolved in methanol 200 g. Thereto, triethylamine 30.3 g (0.3 mol) was added dropwise over 1 hour while the system was maintained at 30°C or less. Then, from the obtained solution, volatile contents were removed using a rotating evaporator at 500C and at 10 to 200 mmHg. Then, the obtained substance was dried at 6O0C under reduced pressure for 3 days to obtain triethylammonium dicyanotriazolate (hereinafter, abbreviated to TEADCTA) ( 65 g, yieldof 98% ) . This triethylammonium dicyanotriazolate had a moisture content of 45 ppm, an excess acid amount of 0.06 * 10"3 mol/g, and an amidated product content of 1.2%. Fig. 6 shows 1H-NMR of the obtained TEADCTA. Fig. 7 shows 13C-NMR of the obtained TEADCTA. The measurements were performed under the following conditions, respectively. This TEADCTA was a buff yellow solid and had a thermal decomposition temperature in nitrogen of 93°C. A mixture of this TEADCTAwith PC 2 mol/kg had an ionic conductivity at 250C of 1.8 * 10"2S/cm.
(Measurement conditions in Fig. 6)
Standard 1H measurement
Pulse sequence: s2pul
Solvent: DMSO
Temperature: Room temperature Device: manufactured by Varian Inc., UNITY plus-400
Relaxation delay: 3.000 seconds
Pulse: 45.0 degree pulse
Incorporation time: 4.000 seconds
Spectral range: 8000.0 Hz The number of times of integration: 16 times
Observation Hl, 399.9694491MHz
Data processing
The number of data point 65536
Measurement time 1 minute and 52 seconds
(Measurement conditions in Fig. 7)
13C measurement
Solvent: DMSO
Temperature: Room temperature Device: GEMINI-200BB gemini2000
Pulse sequence:
Relaxation Delay: 1.000 seconds
Pulse: 44.6 degree pulse
Incorporation time: 1.498 seconds Spectral range: 12500.0 Hz The number of times of integration: 20432 times Observation C13, 50.2732453MHz decouple Hl, 199.9339080MHz power 4IdB continuously on
WALTZ-I 6 modulated Data processing Line breadth: 1.0Hz The number of data point 65536 Measurement time 14.2 hours
Example 3
Into a stirring type 500 mL-autoclave made of SUS, dimethyl carbonate 135 g, 2-methyl imidazoline (42. Ig) , and, as a solvent, methanol 100 g were charged. The mixture was allowed to react with eachother at a reaction temperature of 130°Candat a reaction pressure of 0.7 MPa for 24 hours. After the reaction, the autoclave was cooled and then the reaction liquid was taken out to obtain 1, 2, 3-trimethyimidazolium methyl carbonate (90.0 g, yield of 95.5%) . Then, this 1, 2, 3-trimethyimidazolium methyl carbonate 37.6 g,was dissolved inmethanol 200 g, and then thereto dicyanotriazole 23.8 g was gradually added. As a result, carbon dioxide gas was violently generated. Then, from this mixture, volatile contents were removed at 75°C and at 20 mm Hg using an evaporator. Thereby, 1, 2, 3-trimethylimidazolinium dicyanotriazolate (44.3 g, yieldof 95.8%) was obtained. Aheavy water solution (D2O) of this obtained
1, 2, 3-trimethylimidazolinium dicyanotriazolate was measured for 1H-NMR, and a DMSO-d6 solution of this obtained 1, 2, 3-trimethylimidazolinium dicyanotriazolate was measured for 13C-NMR, therefore, the following signal was obtained. 1H-NMR δ= 2.22 ppm (3H), 3.05 ppm (6H), 3.78 ppm(2H) 13C-NMR δ= 10.7 ppm, 34.0 ppm, 114.2 ppm, 121.9 ppm, 166.9 ppm A mixture of the 1, 2, 3-trimethylimidazolinium dicyanotriazolate with propylene carbonate (hereinafter, abbreviated to PC) 2 mol/kg had an ionic conductivity at 25°C of 2.5 x 10"2 S/cm.
Example 4
Into a stirring type SUS autoclave, dimethyl carbonate 135 g, 2,4-dimethyl imidazoline (49.1 g) , and, as a solvent, methanol 100 g were charged. The mixture was allowed to react with each other at a reaction temperature of 130°Candat a reaction pressure of 0.7 MPa for 24 hours. After the reaction, the autoclave was cooled and then the reaction liquid was taken out to obtain 1, 2, 3, 4-tetramethylimidazolium methyl carbonate (95.6 g, yield of 94.5%) . Then, this 1, 2, 3, 4-tetramethylimidazolium methyl carbonate 40.5 g was dissolved in methanol 200 g, and thereto dicyanotriazole 23.8 g was gradually added. As a result, carbon dioxide gas was violently generated. Then, from this mixture, volatile contents were removed at 75°C and at 20 mm Hg using an evaporator. Thereby, 1, 2, 3, 4-tetramethylimidazolinium dicyanotriazolate (45.1 g, yield of 97.5%) was obtained.
Reference Example (A) 1
The HDCTA 35.7 g ( 0.3 mol ) obtained in the step 2 in Example 1 was dissolved in methanol 200 g. Then, this solution was added into a dispersion Iiquidpreparedby dispersing lithiumcarbonate 11.1 g (0.15 mol) into methanol 300 g over 1 hour. From this obtained solution, volatile contents were removed at 500C and at 10 to 200 mitiHg using a rotating evaporator . Then, the obtained substance was dried at 800C under reduced pressure for 3 days to obtain lithium dicyanotriazolate (hereinafter, abbreviated to LiDCTA) . ALiDCTA-PC solution lmol/L was tried to be prepared. However, the LiDCTA was difficult to dissolve in PC, and a great amount of the LiDCTA was not dissolved and remained, which made it impossible to measure the ionic conductivity. Production Example 1
Into a 2L-separable flask into which water 400 gwas charged, sulfuric acid 98 g (1 mol) and diaminomaleonitrile 216 g (2mol) were added sequentially. Under stirring with a paddle blade, the flask was in an ice bath and thereby the internal temperature was kept at 200C. Simultaneously, an aqueous solution prepared by dissolving sodium nitrite 141.45 g (2.05 mol) in water 410 g was added dropwise over 2 hours. After completion of the dropwise addition, the stirring was continued for 30 minutes. The reaction liquid was subjected to suction filtration with a 0.2 μm mixed cellulose filter to remove insoluble contents therefrom. The obtained filtrate was dried and hardened with a rotating evaporator by removing moisture therefrom. Diisopropyl ether 400g was added to the obtained solid to extract dicyanotriazole therefrom. Then, water 400 g was added to the dicyanopropyl ether phase and thereby impurities causing coloring were washed. The solvent was removed from the diisopropyl ether solution of the dicyanotriazolewith a rotating evaporator. Thereby, HDCTA having a Hazen of 200 was obtained.
Production Example 2
The HDCTA obtained in Production Example 1 was sublimed at one time under reduced pressure for 50 minutes at 125°C and at 30 Pa. Thereby, 100 g of purified HDCTA having a Hazen of 30 was obtained.
Comparative Production Example 1
HDCTA was synthesized according to descriptions in "Lithium Dicyanotriazolate as a Lithium Salt for Poly (ethylene oxide) Based Polymer Electolytes, Electrochemical and Solid-State Letters" 2003, vol.6, No.4, and p. A71 to A73, Egashira and four others) . Diaminomaleonitrile 21.6 g (200mol) , 35% hydrochloric acid 20.9 g (HCL 200 mmol) , and water 236 g were weighed and charged into a 500 mL-separable flask, and themixture was stirred with a paddle blade. The flask was in a dry ice-acetone freezing mixture and thereby the internal pressure was kept at O0C. Simultaneously, sodium nitrite in minute particle form as it is 13.8 g was added over 60 minutes. The reaction liquid was subjected to suction filtration with a 0.2 μm mixed cellulose filter. Then, the obtained filtrate was subjected to extraction by adding diethyl ether 80 g thereto. Thereby, a diethyl ether phase was obtained. This extraction operation was performed three times, and thereby the diethyl ether phase was recovered and then dried and hardened with a rotating evaporator. Thus-obtained solid was sublimed two times under reduced pressure for 150 hours at 800C and 30 Pa. Thereby, HDCTAhaving a Hazen of 30 and an amidatedproduct content of 0.18% was obtained.
Example 5-1
Into water 1000 g, lOOg (0.84 mol) of the HDCTA obtained in Production Example 2 was dissolved. Thereto, a small amount of lithium carbonate was added under stirring at room temperatures until the reaction liquid showed a pH of 7. The reaction liquid,was subjected to suction filtration with a 0.2 μm mixed cellulose filter to remove dusts and the like therefrom. Then, the obtained filtrate was dried andhardened with a rotating evaporator to obtain LiDCTA. The obtained LiDCTA 100 g and toluene 1000 gwere charged into a 2L-separable flask, themixture was subjected to azeotropy dehydration at 500C for 20 minutes and at 130°C for 100 minutes while performing reflux of the toluene. The resulting substance was subjected to suction filtration with a 0.2 μm PTFE filter and the obtained solid was dried at 1400C under reduced pressure. This LiDCTA had a moisture content of 860 ppm, an excess acid amount of 0.05 x 10"3 mol/g, a Hazen of 5, and an amidated product concentration (amidated product content) of 0.20%.
Example 6-1 LiDCTA was obtained in the same manner as in Example 5-1, except that the azeotropy dehydrationwas performedby distilling the toluene without reflux of the toluene. This LiDCTA had a moisture content of 510 ppm, an excess acid amount of 0.05 * 10"3 mol/g, a Hazen of 7 , and an amidated product concentration of 0.19%.
Example 7-1
Into dehydrated acetonitrile (product of KANTO CHEMICAL CO., INC., moisture of 25 ppm) 180g, 20 g of the LiDCTA obtained in Example 5-1 was dissolved. The mixture was dried with a molecular sieve 2 g (UNION SHOWA K. K., Li-A) and then dried substance was subjected to suction filtration with a 0.5 um hydrophilic PTFE filter. The obtained filtrate was dried and hardened with a rotating evaporator and then further dried under reduced pressure. The obtained LiDCTA had a moisture content of 170 ppm, an excess acid amount of 0.05 mmol/g, a Hazen of 160, and an amidated product concentration of 0.14%.
Example 8-1
LiDCTA was obtained in the same manner as in Example 5-1, except that lithium carbonate was added to an aqueous solution containing 10 g of the HDCTA obtained in Production Example 2 until the solution showed a pH of 5. This LiDCTA had a moisture content of 450 ppm, an excess acid amount of 0.15 * 10~3 mol/g, a Hazen of 100, and an amidated product concentration of 0.14%.
Example 9-1
LiDCTA was obtained in the same manner as in Example 5-1, except that lithium carbonate was added to an aqueous solution containing 10 g of the HDCTA obtained in Production Example 2 until the solution showed a pH of 9. This LiDCTA had a moisture content of 450 ppm, an excess acid amount of 0.15 * 10~3 mol/g, a Hazen of 150, and an amidated product concentration of 0.35%. Reference Example (A) 2-1
Into acetonitrile 100 g, 1Og (84mmol) of the HDCA obtained in Comparative Production Example 1 was dissolved. Thereto, lithium carbonate 3.5 g (47 mmol) was added and reaction was performed for 2 hours at room temperatures under stirring. The reaction liquid was subjected to suction filtration with a 0.5 μm hydrophilic PTFE filter to remove residual lithium carbonate therefrom. The obtained filtrate was dried and hardened with a rotating evaporator to obtain LiDCTA. This LiDCTA was dried under reduced pressure at 80°C and at 0.001 Pa.
This LiDCTA had a moisture content of 920 ppm, an excess acid amount of 0.20 mmol/g, a Hazen of 5, and an amidated product concentration of 0.18%.
Reference Example (A) 3-1
LiDCTA was obtained in the same manner as in Example 5-1, except that the toluene was subjected to azeotropic dehydration at 500C for 20 minutes and at 130°C for 40 minutes. This LiDCTA had a moisture content of 1520 ppm, an excess acid amount of 0.05 x 10"3 mol/g, a Hazen of 7, and an amidated product concentration of 0.19%.
Reference Example (A) 4-1
LiDCTA was obtained in the same manner as in Example 5-1, except that lithium carbonate was added to an aqueous solution containing 10 g of the HDCTA obtained in Production Example 2 until the solution showed a pH of 10. This LiDCTA had a moisture content of 450 ppm, an excess acid amount of 0.2 * 10"3 mol/g, a Hazen of 140, and an amidated product concentration of 0.18%.
Reference Example (A) 5-1
LiDCTA was obtained in the same manner as in Example 5-1, except that the toluene was subjected to azeotropic dehydration at 500C for 20 minutes and at 1300C for 70 minutes. This LiDCTA had a moisture content of 1080 ppm, an excess acid amount of 0.05 x 103ItIoIZg, a Hazen of 6, and an amidated product concentration of 0.20%.
Reference Example (A) 6-1 Into acetonitrile 100 g, 1Og (84miτιol) of the HDCA obtained in Comparative Production Example 1 was dissolved. Thereto, lithium carbonate 3.5 g (47 mmol) was added and reaction was performed for 2 hours at room temperatures under stirring. The reaction liquid was subjected to suction filtration with a 0.5 μmhydrophilic PTFE filter to remove unreacted lithium carbonate therefrom. The obtained filtrate had a pH of 7. This filtrate was dried and hardened with a rotating evaporator to obtained LiDCTA. This obtained LiDCTA 1Og and toluene 100 g were charged into a 200 mL-separable flask. The mixture was subjected to azeotropy dehydration at 1300C for 120 minutes while performing reflux of the toluene. This was subjected to suction filtration with a 0.2 μm PTFE filter and the obtained solid was dried at 1400C under reduced pressure.
This LiDCTA had a moisture content of 600 ppm, an excess acid amount of 0.21 mmol/g, a Hazen of 6, and an amidated product concentration of 0.21%.
Reference Example (B) 1-1
LiDCTA was obtained in the same manner as in Example 5-1, except that 10 g of the HDCTA obtained in Production Example
1 was used. This LiDCTA had a moisture content of 700 ppm, an excess acid amount of 0.05 x 10~3 mol/g, and a Hazen of 240.
Reference Example (B) 2-1 LiDCTA was obtained in the same manner as in Example 5-1, except that the azeotropy of the toluene was performed at 1500C for 120 minutes . This LiDCTA had a moisture content of 980 ppm, an excess acid amount of 0.05 x 10"3 mol/g, a Hazen of 5, and an amidated product concentration of 1.05%. Reference Example (B) 3-1
LiDCTA was obtained in the same manner as in Example 5-1, except that the azeotropy of the toluene was performed at 170°C for 120 minutes . This LiDCTA had a moisture content of 920 ppm, an excess acid amount of 0.06 x 10"3 mol/g, a Hazen of 4, and an amidated product concentration of 3.01%.
(Evaluation of reactivity with electrode)
In an atmosphere in which the dew point was controlled at -60°C or less, one drop of a solution prepared by dissolving LiDCTA 3 g in acetonitrile for batteries 30 g was applied on a lithium (Li) foil, and this foil was kept standing for 3 minutes . Then, the foil surface was sufficiently washed with acetonitrole for batteries and then dried for 30 minutes. Then, the surface was observed and the reactivity of, the negative foil (Li-foil) with the acetonitrile-LiDCTA solution was evaluated.
Example 5-2
The LiDCTA described in Example 5-1 was subjected to the evaluation test of reactivity with the electrode. No change was observed on the Li-foil surface.
Example 6-2
The LiDCTA described in Example 6-1 was subjected to the evaluation test of reactivity with the electrode. No change was observed on the Li-foil surface.
Example 7-2
The LiDCTA described in Example 7-1 was subjected to the evaluation test of reactivity with the electrode. No change was observed on the Li-foil surface.
Example 8-2
The LiDCTA described in Example 8-1 was subjected to the evaluation test of reactivity with the electrode. No change was observed on the Li-foil surface.
Example 9-2
The LiDCTA described in Example 9-1 was subjected to the evaluation test of reactivity with the electrode." No change was observed on the Li-foil surface.
Reference Example (A) 2-2
The LiDCTA described in Reference Example (A) 2-1 was subjected to the evaluation test of reactivity with the electrode , The portion on the Li-foil surface where the LiDCTA solution was applied was turned black.
Reference Example (A) 3-2 The LiDCTA described in Reference Example (A) 3-1 was subjected to the evaluation test of reactivity with the electrode . The portion on the Li-foil surface where the LiDCTA solution was applied was turned black.
Reference Example (A) 4-2
The LiDCTA described in Reference Example (A) 4-1 was subjected to the evaluation test of reactivitywith the electrode .
Deposition of insoluble contents was observed on the Li-foil surface.
Reference Example (A) 5-2
The LiDCTA described in Reference Example (A) 5-1 was subjected to the evaluation test of reactivity with the electrode .
The portion on the Li-foil surface where the LiDCTA solution was applied was turned black.
Reference Example (A) 6-2
The LiDCTA described in Reference Example (A) 6-1 was subjected to the evaluation test of reactivity with the electrode. The portion on the Li-foil surface where the LiDCTA solution was applied was turned black.
Reference Example (B) 1-2
The LiDCTA described in Reference Example (B) 1-1 was subjected to the evaluation test of reactivity with the electrode, No change was observed on the Li-foil surface.
Reference Example (B) 2-2
The LiDCTA described in Reference Example (B) 2-1 was subjected to the evaluation test of reactivity with the electrode . No change was observed on the Li-foil surface.
Reference Example (B) 3-2
The LiDCTA described in Reference Example (B) 3-1 was subjected to the evaluation testofreactivitywith the electrode . No change was observed on the Li-foil surface.
The above-mentioned results show that if the LiDCTA of the present invention is used as an electrolyte constituting an ionic conductor of a battery, the battery has excellent charge and discharge properties and has long-term reliability.
(Charge and discharge test)
(Preparation of cathode) LiDCTA, V2Os, acetyleneblack, andPEO (polyethylene oxide) were dissolved in acetonitrile, and dispersed with a homomixer .
Therefrom, fine dusts were removed with a filter . Thus-prepared solution was applied on an aluminum foil to have a thickness of 300 μm and dried at 60°C for 30 minutes under reduced pressure . This foil was pressed at 25 Mpa with a pressing machine for 5 minutes to obtain a cathode.
(Preparation of solid electrolyte (SPE) )
LiDCTA, P(E0/AGE) (poly (ethylene oxide-allyl glycidyl ether) copolymer) , and Irgacure 651 (2, 2-dimethoxy-l, 2-diphenylethane-l-one) were dissolved in acetonitrile. This mixture was sufficiently stirred with a magnetic stirrer to be homogeneous. Therefrom, insoluble contents were removed with a filter and degassing was performed under reduced pressure. Thus-prepared solution was applied on a copper foil to have a thickness of 250 μm and dried at 60°C for 30 minutes under reduced pressure. This foil was irradiated with ultraviolet and thereby a polymer was cross-linked. This obtained filmwas further driedat 600C for one night under reduced pressure. As a result, a SPE was prepared.
(Preparation of coin battery)
The cathode, the SPE, each prepared by the above-mentioned methods, and a lithium foil were circularly pierced using punches having a diameter of 12 mm, 16 mm, and 14 mm. The lithium foil, the SPE, and the cathode were stuck together in this order. This was sandwiched with two circular stainless plates each with a diameter of 16 mm. Further, a spring spacer was placed on the positive electrode side and then this was put into a CR2032 type batterycan. Thisbattery canwas caulkedwitha caulkingmachine to prepare a coin battery.
(Charge and discharge test)
Thus-prepared coin battery was subjected to charge and discharge test with a charge and discharge test device (product of ASUKA ELECTRONICIS CO. , LTD. ) . The constant current charge and discharge test was performed under the following test conditions: a temperature of 60°C; a voltage range of 3.2 V to 2.2 V; an initial current density of 6 mA/g in trial run, and then 20 mA/g, relative to the weight of the positive substance. In evaluation of cycle characteristics of the battery, whether or not the discharge capacity at 10th cycle is reduced and the resistance between the electrodes was measured as an indicator for evaluating the existence of the film formation during the charge and discharge cycles. Example 5-3
Using the LiDCTA described in Example 5-1, three coin batteries were prepared by the above-mentioned method. The three coin batteries were subjected to the charge and discharge test . The coin batteries showed excellent charge and discharge properties.
Reference Example (B) 1-3 Using the LiDCTA described in Reference Example (B) 1-1, three coinbatteries werepreparedby the above-mentionedmethod. The three coin batteries were subjected to the charge and discharge test . The results showed that the three coinbatteries could not be used as a secondary battery because the capacitor was remarkably reduced and the resistance between the electrodes after the test was also remarkably increased.
Reference Example (B) 2-3
Using the LiDCTA described in Reference Example (B) 2-1, three coinbatteries werepreparedby the above-mentionedmethod. The three coin batteries were subjected to the charge and discharge test. The discharge capacitor was slightly reduced, but the resistance between the electrodes after the test was hardly increased.
Reference Example (B) 3-3
Using the LiDCTA described in Reference Example (B) 3-1, three coinbatteries werepreparedby the above-mentionedmethod. The three coin batteries were subjected to the charge and discharge test . The results showed that the three coinbatteries could not be used as a secondary battery because the discharge capacitor was slightly reduced and the resistance between the electrodes after the test was clearly increased. Tables 1 and 2 show the results.
Figure imgf000084_0001
[Table 2]
Figure imgf000085_0001

Claims

1. An ionic compound having: a moisture content of 1000 ppm or less; and an excess acid amount or an excess base amount of less than 0.2 x 10"3 mol/g, wherein the ionic compound comprises dicyanotriazolate anion and at least one cation selected from the group consisting of cations represented by the following formula (1) :
Rs L ® ( l ) (in the formula, L representing at least one element selected from the group consisting of C, Si, N, P, S, and O; R being the same or different and each representing a monovalent element or an organic group, and may be bonded together; and s being an integer of 3 to 5 and being a value determined by the valency of the element L) and alkali metal ions.
2. The ionic compound according to Claim 1, wherein the ionic compound has a Hazen value of 200 or less.
3. An ionic compound comprising dicyanotriazolate anion, wherein the ionic compound contains 1.5% by weight or less of an amidated product of the dicyanotriazolate anion.
4. An ionic compound comprising dicyanotriazolate anion and a cation represented by the following formula (1) :
Rs L ( l )
(in the formula, L representing at least one element selected from the group consisting of C, Si, N, P, S, and 0; Rbeing the same or different, and each representing a monovalent element or an organic group, and may be bonded together; and s being an integer of 3 to 5 and being a value determined by the valency of the element L) .
5. An ionic composition comprising an ionic compound and having a moisture content of 1000 ppm or less, wherein the ionic compound has an excess acid amount or an excess base amount of less than 0.2 * 10"3 mol/g.
6. The ionic composition according to Claim 5, wherein the ionic compound comprising lithium ion.
7. A battery prepared using the ionic compound of any of Claims 1 to 4 and/or the ionic composition of Claim 5 or 6.
PCT/JP2006/322693 2005-11-11 2006-11-08 Ionic compound WO2007055392A1 (en)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP2005328032A JP5066334B2 (en) 2005-11-11 2005-11-11 Ionic compounds
JP2005-328032 2005-11-11
JP2005-342681 2005-11-28
JP2005342681 2005-11-28
JP2006-271962 2006-10-03
JP2006271962A JP5224675B2 (en) 2005-11-28 2006-10-03 Lithium dicyanotriazolate

Publications (1)

Publication Number Publication Date
WO2007055392A1 true WO2007055392A1 (en) 2007-05-18

Family

ID=38023380

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2006/322693 WO2007055392A1 (en) 2005-11-11 2006-11-08 Ionic compound

Country Status (1)

Country Link
WO (1) WO2007055392A1 (en)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2219260A1 (en) * 2007-11-30 2010-08-18 Fujikura, Ltd. Electrolytic composition and photoelectric conversion element using the same
CN102195082A (en) * 2010-03-05 2011-09-21 索尼公司 Lithium secondary battery, electrolytic solution for lithium secondary battery, electric power tool, electrical vehicle, and electric power storage system
US20110229769A1 (en) * 2010-03-17 2011-09-22 Sony Corporation Lithium secondary battery, electrolytic solution for lithium secondary battery, electric power tool, electrical vehicle, and electric power storage system
EP2729948A4 (en) * 2011-07-08 2015-03-04 Fastcap Systems Corp High temperature energy storage device
EP2817810A4 (en) * 2012-02-24 2015-10-21 Fastcap Systems Corp Advanced electrolyte systems and their use in energy storage devices
CN110071323A (en) * 2018-01-20 2019-07-30 中南大学 A kind of optoelectronic integration film power-supply system and its preparation and application
US10872737B2 (en) 2013-10-09 2020-12-22 Fastcap Systems Corporation Advanced electrolytes for high temperature energy storage device
CN112117130A (en) * 2020-10-16 2020-12-22 新疆众和股份有限公司 Six-stage formation process of high-stability high-voltage anode foil
US11127537B2 (en) 2015-01-27 2021-09-21 Fastcap Systems Corporation Wide temperature range ultracapacitor
US11250995B2 (en) 2011-07-08 2022-02-15 Fastcap Systems Corporation Advanced electrolyte systems and their use in energy storage devices
WO2022144511A1 (en) * 2021-01-04 2022-07-07 Arkema France Ionic liquid based on bis(fluorosulfonyl)imide
CN115440504A (en) * 2021-06-02 2022-12-06 重庆三峡学院 Mo-CoP @ Ni-Fe LDH core-shell hierarchical nanosheet and preparation method and application thereof
CN118184596A (en) * 2024-05-14 2024-06-14 广东工业大学 Silver-sodium ion material with photoelectric dual property and preparation method and application thereof

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2194127A1 (en) * 1996-12-30 1998-06-30 Christophe Michot Delocalized anions for use as electrolytic solutes
WO1999034471A1 (en) * 1997-12-26 1999-07-08 Tonen Corporation Electrolyte for lithium cells and method of producing the same
JP2000508676A (en) * 1996-12-30 2000-07-11 イドロ―ケベック Five-membered anion salts or tetraazapentalene derivatives and their use as ion-conducting substances
JP2006199646A (en) * 2005-01-21 2006-08-03 Nippon Shokubai Co Ltd Method for producing ionic compound

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2194127A1 (en) * 1996-12-30 1998-06-30 Christophe Michot Delocalized anions for use as electrolytic solutes
JP2000508676A (en) * 1996-12-30 2000-07-11 イドロ―ケベック Five-membered anion salts or tetraazapentalene derivatives and their use as ion-conducting substances
WO1999034471A1 (en) * 1997-12-26 1999-07-08 Tonen Corporation Electrolyte for lithium cells and method of producing the same
JP2006199646A (en) * 2005-01-21 2006-08-03 Nippon Shokubai Co Ltd Method for producing ionic compound

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
BOENNEMAN H. ET AL.: "Chloride free Pt- and PtRu-nanoparticles stabilised by "Armand's ligand" as precursors for fuel cell catalysts", FUEL CELLS, vol. 4, no. 4, 2004, pages 289 - 296, XP003009675 *
EGASHIRA M. ET AL.: "Lithium dicyanotriazolate as a lithium salt for poly(ethylene oxide) based polymer electrolytes", ELECTROCHEMICAL AND SOLID-STATE LETTERS, vol. 6, no. 4, 2003, pages A71 - A73, XP003009674 *

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2219260A1 (en) * 2007-11-30 2010-08-18 Fujikura, Ltd. Electrolytic composition and photoelectric conversion element using the same
EP2219260A4 (en) * 2007-11-30 2011-03-09 Fujikura Ltd Electrolytic composition and photoelectric conversion element using the same
AU2008330576B2 (en) * 2007-11-30 2012-01-12 Fujikura Ltd. Electrolyte composition and photoelectric conversion element incorporating the same.
US8257615B2 (en) 2007-11-30 2012-09-04 Fujikura Ltd. Electrolyte composition and photoelectric conversion element incorporating the same
CN102195082A (en) * 2010-03-05 2011-09-21 索尼公司 Lithium secondary battery, electrolytic solution for lithium secondary battery, electric power tool, electrical vehicle, and electric power storage system
US20110229769A1 (en) * 2010-03-17 2011-09-22 Sony Corporation Lithium secondary battery, electrolytic solution for lithium secondary battery, electric power tool, electrical vehicle, and electric power storage system
US11482384B2 (en) 2011-07-08 2022-10-25 Fastcap Systems Corporation High temperature energy storage device
US11250995B2 (en) 2011-07-08 2022-02-15 Fastcap Systems Corporation Advanced electrolyte systems and their use in energy storage devices
US11901123B2 (en) 2011-07-08 2024-02-13 Fastcap Systems Corporation High temperature energy storage device
US10714271B2 (en) 2011-07-08 2020-07-14 Fastcap Systems Corporation High temperature energy storage device
US11776765B2 (en) 2011-07-08 2023-10-03 Fastcap Systems Corporation Advanced electrolyte systems and their use in energy storage devices
EP2729948A4 (en) * 2011-07-08 2015-03-04 Fastcap Systems Corp High temperature energy storage device
EP2817810A4 (en) * 2012-02-24 2015-10-21 Fastcap Systems Corp Advanced electrolyte systems and their use in energy storage devices
US10872737B2 (en) 2013-10-09 2020-12-22 Fastcap Systems Corporation Advanced electrolytes for high temperature energy storage device
US11488787B2 (en) 2013-10-09 2022-11-01 Fastcap Systems Corporation Advanced electrolytes for high temperature energy storage device
US11127537B2 (en) 2015-01-27 2021-09-21 Fastcap Systems Corporation Wide temperature range ultracapacitor
US11756745B2 (en) 2015-01-27 2023-09-12 Fastcap Systems Corporation Wide temperature range ultracapacitor
CN110071323B (en) * 2018-01-20 2020-08-04 中南大学 Photoelectric integrated thin film power supply system and preparation and application thereof
CN110071323A (en) * 2018-01-20 2019-07-30 中南大学 A kind of optoelectronic integration film power-supply system and its preparation and application
CN112117130B (en) * 2020-10-16 2021-12-07 新疆众和股份有限公司 Six-stage formation process of high-stability high-voltage anode foil
CN112117130A (en) * 2020-10-16 2020-12-22 新疆众和股份有限公司 Six-stage formation process of high-stability high-voltage anode foil
WO2022144511A1 (en) * 2021-01-04 2022-07-07 Arkema France Ionic liquid based on bis(fluorosulfonyl)imide
FR3118679A1 (en) * 2021-01-04 2022-07-08 Arkema France Ionic liquid based on bis(fluorosulfonyl)imide
CN115440504A (en) * 2021-06-02 2022-12-06 重庆三峡学院 Mo-CoP @ Ni-Fe LDH core-shell hierarchical nanosheet and preparation method and application thereof
CN118184596A (en) * 2024-05-14 2024-06-14 广东工业大学 Silver-sodium ion material with photoelectric dual property and preparation method and application thereof

Similar Documents

Publication Publication Date Title
US8273263B2 (en) Ionic compound
WO2007055392A1 (en) Ionic compound
KR100714135B1 (en) Material for electrolytic solutions and use thereof
US20080138704A1 (en) Material for Electrolytic Solution, Ionic Material-Containing Composition and Use Thereof
JP5366460B2 (en) Ionic compounds
EP1763099A2 (en) Stable electrolyte counteranions for electrochemical devices
JP4187113B2 (en) Ionic compounds
JP4439797B2 (en) Ion conductor materials
JP2007197370A (en) Electrolyte composition
JP5684138B2 (en) Electric storage device and electrolyte used therefor
JP5066334B2 (en) Ionic compounds
JP5595294B2 (en) Additive for electrolytic solution of power storage device and electrolytic solution containing the same
JP2006202646A (en) Ionic liquid composition, ion-conductive material, and electrolyte material
JP2006173014A (en) Ionic material-contained composition, ion conductive material, and use thereof
JP5025092B2 (en) Electrolyte material
JP4249495B2 (en) Ion conductive material
JP2004292350A (en) Ionic compound
JP2007157584A (en) Electrolyte material
JP2004123653A (en) Method for producing ionic material
JP4732764B2 (en) Process for producing ionic compounds
JP2004123652A (en) Method for producing ionic material
JP2004227909A (en) Manufacturing method of ionizable matter
JP2006193460A (en) Quaternary ammonium salt, electrolyte and electrochemical device
JP2007134184A (en) Ionic composition

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 06823395

Country of ref document: EP

Kind code of ref document: A1