WO2006135029A1

WO2006135029A1 - Electrolyte containing oxocarbon and use thereof

Info

Publication number: WO2006135029A1
Application number: PCT/JP2006/312074
Authority: WO
Inventors: Ken Yoshimura
Original assignee: Sumitomo Chemical Company, Limited
Priority date: 2005-06-17
Filing date: 2006-06-09
Publication date: 2006-12-21
Also published as: TW200710077A

Abstract

As an electrolyte that is useful as an electrolyte of lithium secondary battery, etc., excels in chemical stability and can retain high lithium conductivity over a prolonged period of time, there is provided an electrolyte characterized by containing an oxocarbon and a low-molecular compound.

Description

Specification

ELECTROLYTE CONTAINING OXO POWER

The present invention relates to an electrolyte containing oxocarbons and a low molecular weight compound and use thereof. Background art

It is known that oxocarbons typified by squaric acid (square acid) have a high acidity because the hydrogen dissociated state in the oxocarbon group has a stable structure due to resonance (〇xo car bon s, 45 Page (Ed ited by Robert We st), Ac ad emi c Pres (1980), (ISBN: 0- 12-744580-3) (J ou rnaloft he Ame ric an Ch emi cal S ociety, 95, 8703 ( 1973) On the other hand, electrolytes, especially nonaqueous electrolytes, are used as electrolytes for energy storage devices such as lithium secondary batteries, and these devices have high voltage and high energy density and are highly reliable. Therefore, it is widely used in power supplies for electronic devices, etc. Non-aqueous electrolytes are composed of non-aqueous solvents and inorganic salts, and non-aqueous solvents are generally high-dielectric constant organic solvents such as propylene carbonate, Ptylolactone, sulfolane, or low viscosity An organic solvent Jimechiruka one port Ne Ichito, dimethoxy E Tan, Te tetrahydrofuran, 1, 3 Jiokisoran is used. Also in the inorganic salt _{L i C 10 4, L i} PF 6, L i A s F ₆ , L i S b F ₆ , L i BF ₄ , L i CF ₃ S0 ₃ , L i N (CF ₃ S0 ₂ ) ₂ , L i C (CF ₃ S0 ₂ ) ₃ , L i ₂ B _₁₀ C 1 _10, a lower fat aliphatic carboxylic acid lithium salts, such as L i a l C 1 ₄ are used. dISCLOSURE oF iNVENTION

However, electrolytes composed of oxonobon and low molecular weight compounds are known. Absent.

As a result of manufacturing various electrolytes made of oxocarbons and low molecular weight compounds, the present inventors have found that electrolytes containing oxocarbons are useful as electrolytes such as lithium secondary batteries, and inorganic. The present invention was completed by finding out that it has lithium conductivity comparable to an electrolyte composed of a salt and an organic solvent, has excellent chemical stability, and can maintain high lithium conductivity over a long period of time.

That is, the present invention relates to an electrolyte comprising: [1] oxocarbons and a low molecular compound having a molecular weight of less than 1000.

Further, the present invention provides: [2] The electrolyte according to [1], wherein the oxodynamic force is represented by the following formula (1):

(Wherein X ¹ and X ² each independently represent —O—, 1 S— or 1 NR ′ —, Z represents 1 CO—, 1 C (S) 1 and 1 C (NR ′ ′) —, Represents an optionally substituted alkylene group having 1 to 6 carbon atoms or an optionally substituted arylene group having 6 to 10 carbon atoms, n represents the number of repetitions, and 0 to Represents an integer of 10. The n Z's may be the same or different from each other R may have _OH, -SH, — NHR ''', or a substituent An alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms which may have a substituent, or an aralkyl group having 16 to 16 carbon atoms which may have a substituent R ′, R ′ ′ and R ′ ′ ′ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an optionally substituted carbon group having 6 to 10 carbon atoms. B represents an aryl group of It represents an atom or a monovalent metal atom.)

[3] Z is one CO_, one C (S) — or one C (NH) —. [2] the electrolyte according to the above,

[4] The electrolyte according to any one of [2] to [3], wherein X ¹ and X ^{2 are} −001, Z is —CO—, and n is any of 0 to 2,

[5] The electrolyte according to any one of [2] to [4], wherein B is selected from a hydrogen atom, a lithium atom, a sodium atom, a potassium atom, and a cesium atom,

[6] The electrolyte according to any one of [1] to [6], wherein the low molecular weight compound is a compound that exhibits a liquid state at 25 ° C.

[7] The electrolyte according to any one of [1] to [6], wherein the low-molecular compound is an aprotic compound,

[8] The electrolyte according to any one of [1] to [7], wherein the low molecular compound is a low molecular compound having a dielectric constant of 50 or more,

[9] The electrolyte according to any one of [1] to [8], wherein the low molecular weight compound is a cyclic carbonate.

[1 0] The electrolyte according to any one of [1] to [9], wherein the low molecular weight compound includes one or both of ethylene carbonate and propylene power monoponate,

[1 1] [Substance of oxocarbons (mm o 1) 1 / [Weight of low molecular weight compound (g) + Weight of oxobons (g)] is 0.05 to 8 mm o 1 / g The electrolyte according to any one of [1] to [10],

[12] A battery comprising the electrolyte according to any one of [1] to [11],

[1 3] The battery according to [1 2], wherein the battery is a lithium secondary battery. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

The electrolyte of the present invention is characterized by containing oxocarbons and a low molecular weight compound. Here, a representative example of oxocarbons is a compound represented by the following formula (1).

(In the formula, X ¹ and X ² each independently represent —O—, 1 S— or 1 NR ′ —, Z represents one CO_, one C (S) one, one C (NR ′,) —, substitution Represents an alkylene group having 1 to 6 carbon atoms which may have a group or an arylene group having 6 to 10 carbon atoms which may have a substituent, n represents the number of repetitions, and 0 to 10 N may be the same as or different from each other, and R may be 10H, — SH, 1 NHR ''', or may have a substituent. Represents an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms which may have a substituent, or an aralkyl group having 16 to 16 carbon atoms which may have a substituent. R, R ′ ′, and R ′ ′ ′ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an optionally substituted carbon group. Represents an aryl group of the number 6 to 10. B is Represents a hydrogen atom or a monovalent metal atom.)

In the oxocarbons represented by the formula (1), the free acid in which B is a hydrogen atom has high acidity.

In the oxocarbons represented by the formula (1), X ¹ and X ² each independently represent —O—, —S— or —NR′—. R ′ is a hydrogen atom, a methyl group, a trifluoromethyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, etc., and an optionally substituted alkyl group having 1 to 6 carbon atoms, Alternatively, it represents an aryl group having 6 to 10 carbon atoms, which may have a substituent represented by a phenyl group, a phenylfluorophenyl group, a naphthyl group, or the like. R ′ is preferably a hydrogen atom. X ¹ and X ² are preferably either 101 or 1 S—, particularly preferably both One is O-.

Z is one CO—, one C (S) one, — C (NR, ') one, an optionally substituted alkylene group having 1 to 6 carbon atoms or a substituent. Represents an arylene group having 6 to 10 carbon atoms. R ′ ′ is a hydrogen atom, a methyl group, a trifluoromethyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group and the like. It represents an aryl group having 6 to 10 carbon atoms which may have a substituent represented by an alkyl group, a phenyl group, a penufluorofluorophenyl group, a naphthyl group or the like. R ′ ′ is preferably a hydrogen atom.

Here, examples of the alkylene group having 1 to 6 carbon atoms include methylene, ethylene, propylene, i-propylene, butylene, and pentylene. Examples of the arylene group having 6 to 10 carbon atoms include phenylene and naphthylene. In the case of having a substituent, examples of the substituent include haguchi atom such as fluorine, chlorine, bromine, etc. Among them, fluorine is preferably used.

Z is preferably —CO—, 1 C (S) —, 1 C (NR ′ ′) —, methylene, difluoromethylene, phenylene, tetrafluorophenylene, etc., more preferably —C ○ 1, 1 C (S) 1st grade, particularly preferably 1 CO— etc. n represents the number of repetitions of Z, and represents the number of η = 0-10. The n Zs may be the same or different. n is preferably 0 to 4, more preferably 0 to 2, and particularly preferably 1.

R is —OH, _SH, —NHR ′ ′ ′, an optionally substituted alkyl group having 1 to 18 carbon atoms, an optionally substituted aryl group having 6 to 18 carbon atoms, or a substituent. An aralkyl group having 7 to 16 carbon atoms which may have a group. R ′ ′ ′ is a hydrogen atom, a methyl group, a trifluoromethyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group and the like. 6 represents an aryl group having 6 to 10 carbon atoms which may have a substituent represented by 6 alkyl group, phenyl group, penufluorophenyl group, naphthyl group or the like. R ′ ′ ′ is preferably a hydrogen atom. Here, examples of the alkyl group having 1 to 18 carbon atoms include methyl, ethyl, propyl, i-propyl, n-butyl, sec-butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, Examples include decyl, undecyl, dodecyl, tridecyl, tetradecyl, pen decyl, hexadecyl, hepdecyl, and decyl decyl.

Examples of the substituent when the alkyl group having 1 to 18 carbon atoms has a substituent include, for example, halogens such as fluoro, black mouth, and bromo, alkoxy having 1 to 5 carbon atoms such as nitro, cyan, methoxy, ethoxy, and propoxy , Fluoroalkyls having 1 to 5 carbon atoms such as trifluoromethyl and penufluoromethyl.

Examples of the aryl group having 6 to 18 carbon atoms include phenyl, naphthyl, and anthranyl. When the aryl group having 6 to 18 carbon atoms has a substituent, examples of the substituent include halogens such as fluoro, black mouth, and bromo, nitro, cyan, methoxy, ethoxy, and propoxy. Examples thereof include fluoroalkyl having 1 to 5 carbon atoms such as alkoxy, trifluoromethyl and pentafluoromethyl, and alkyl having 1 to 5 carbon atoms such as methyl, ethyl, propyl and butyl. Examples of the aralkyl group having 7 to 16 carbon atoms include benzyl, phenylethyl, phenylpropyl, naphthylmethyl, naphthylethyl and the like. Examples of the substituent in the case where the aralkyl group having 7 to 16 carbon atoms has a substituent include halogens such as fluoro, black mouth and bromo, nitro, cyan, methoxy, ethoxy, propoxy and the like having 1 to 5 carbon atoms. Examples thereof include fluoroalkyl having 1 to 5 carbon atoms such as alkoxy, trifluoromethyl and pentafluoromethyl, and alkyl having 1 to 5 carbon atoms such as methyl, ethyl, propyl and butyl.

R is preferably one OH, one SH, a methyl group, an ethyl group, a trifluoromethyl group, a phenyl group, a naphthyl group, a pentafluorophenyl group, a benzyl group, etc., more preferably _OH, a phenyl group. And penfluorofluorophenyl group.

B represents a hydrogen atom or a monovalent metal atom. Examples of monovalent metal atoms include lithium atoms, sodium atoms, potassium atoms, cesium atoms, and silver atoms. B is preferably a hydrogen atom, a lithium atom, a sodium atom, a potassium atom, or a cesium atom, more preferably a hydrogen atom, a lithium atom, a sodium atom, or a potassium atom, and even more preferably a hydrogen atom or a lithium atom. is there. When the electrolyte of the present invention is used as an electrolyte for a lithium secondary battery, B is preferably a lithium atom.

When the electrolyte of the present invention is used for a polymer electrolyte fuel cell, B is preferably a hydrogen atom.

Examples of the oxopower compounds represented by the formula (1) in the present invention include the following compounds. Here, although the case where B is a hydrogen atom is illustrated, these metal salts may be used.

6Z0 / 900i OAV

In the present invention, the above oxocarbons are used. Among these,

(a 1) to (a 54) are preferred. (A 2), (a 5) (a 8), (all), 14), (al 7), (a 20), (a 23), (a 26), (a 29), ( a 32), (a 35), (a 38), (a 1) (a44), (a47), (a 50), (a 53), and more preferably (a 2), (a 5 ), (Al 7), (a 26), (a 29)> (a41), (a44), (a 50), (a 53), particularly preferably (a 2), (a41) is there.

For example, the oxo power can be produced according to the following method. They may also be obtained from reagent manufacturers.

(I) A method for producing a compound in which R in the oxocarbons (1) is alkyl or aryl using a lithium reagent (Journa 1 of Organic Chemistry, 53, 2482, 2477 (1988) )). (II) A method for producing a compound in which R in the oxocarbons (1) is alkyl or aryl using a Grignard reagent (Heterocycles, 27 (5), 1191 (1988)).

(III) A method for producing a compound in which R in the oxocarbons (1) is alkyl or aryl using a tin reagent (Jo u rna 1 o f Or g an i c

C emi s tr y, 55, 5359 (1990), Tetrahyrdon Le tert rs, 31 (30), 4293 (1990)).

(IV) A method of synthesis using the Fri e dl C r afts reaction (Syn ht e sis, p. 46 (1974)).

Various derivatives can be synthesized by complying with these methods.

When the ester is obtained by the method of (I) to (IV), the ester is hydrolyzed with an acid or alkali to obtain an oxocarbon in which B in the general formula (1) is a hydrogen atom. Can do. When B in the formula (1) is a monovalent metal ion, it can be obtained by neutralizing the free acid oxocarbons with a solution containing an alkali metal hydroxide.

The electrolyte of the present invention is characterized by containing the above oxocarbons and a low molecular weight compound.

As the low molecular weight compound in the present invention, those having a molecular weight of less than 1000 are preferably used. More preferably, a molecular weight of 700 or less, particularly preferably a molecular weight of 500 or less is used.

A compound showing a liquid state at 1 atmosphere and 25 ° C. is preferred.

Low molecular weight compounds include alcohols, ketones, ethers, halogens, sulfoxides, sulfones, amides, aliphatic hydrocarbons, aromatic hydrocarbons, carbonates, esters, nitriles, oligoalkylene glycols, and mixtures thereof. In addition, those having a fluorine atom-containing substituent (fluorine substituent) introduced may be mentioned. As alcohol, methanol, ethanol, isopropanol, butanol And benzophenone. Examples of ethers include jetyl ether, dibutyl ether, diphenyl ether, tetrahydrofuran (hereinafter abbreviated as TH F), dioxane, dioxolane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, And propylene glycol monoethyl ester.

The eight-logen includes black mouth form, dichloromethane, 1,2-dichloroethane, 1,1,2,2,2-tetrachloroethane, black mouth benzene, dichlorobenzene, and the like. The sulfoxide is dimethyl sulfoxide (hereinafter abbreviated as DMSO). )). As sulfone, diphenyl sulfone, sulfolane, etc., as amide, N, N-dimethylacetamide (hereinafter abbreviated as DMAc), N-methylacetamide, N, N-dimethylformamide (hereinafter abbreviated as DMF), N-methylformamide, formamide, N-methylpyrrolidone (hereinafter abbreviated as NMP), and the like. Examples of aliphatic hydrocarbons include pentane, hexane, heptane, and octane, and examples of aromatic hydrocarbons include benzene, toluene, and xylene.

Examples of carbonate esters include propylene carbonate, ethylene carbonate, dimethyl carbonate, jetyl carbonate, ethyl methyl carbonate, 4-trifluoromethyl-1,3-dioxolan-2-one, 1,2-di (methoxycarbonyloxy) Ethane is methyl formate, methyl acetate, and r-ptilolactone, nitrile is acetonitrile, ptyronitrile, etc., and oligoalkylene glycol is oligo (ethylene glycol), oligo (propylene glycol), Oligo (butylene glycol) and the like can be mentioned.

When the electrolyte of the present invention is used as an electrolyte for a lithium secondary battery, an aprotic solvent is mainly used as the low molecular weight compound. Examples of such low molecular weight compounds include carbonic acid esters, ethers, esters, nitriles, amides, sulfoxides, sulfones, mixtures thereof, or further fluorine substituents. Things.

Among these, carbonic acid esters, ethers, esters, mixtures thereof, or those in which a fluorine substituent is further introduced are preferable.

The low molecular weight compound is preferably a compound having a dielectric constant of 20 or more, more preferably 30 or more, further preferably 40 or more, and more preferably 50 or more, from the viewpoint of solubility of oxocarbons and ion conductivity. Are particularly preferred.

When two or more kinds of low molecular compounds are used, the high dielectric constant component having a dielectric constant of 20 or more is preferably 20% by weight or more based on the total weight of the low molecular compounds, and 30% by weight. % Or more, more preferably 40% by weight or more, and particularly preferably 50% by weight or more.

When two or more kinds of low molecular compounds are used, the high dielectric constant component having a dielectric constant of 30 or more is preferably 20% by weight or more based on the total weight of the low molecular compounds, and 30% by weight. % Or more, more preferably 40% by weight or more, and particularly preferably 50% by weight or more.

When two or more kinds of low molecular compounds are used, the high dielectric constant component having a dielectric constant of 40 or more is preferably 20% by weight or more based on the total weight of the low molecular compounds, and 30% by weight. % Or more, more preferably 40% by weight or more, and particularly preferably 50% by weight or more.

When two or more kinds of low molecular compounds are used, the high dielectric constant component having a dielectric constant of 50 or more is preferably 20% by weight or more based on the total weight of the low molecular compounds, and 30% by weight. % Or more, more preferably 40% by weight or more, and particularly preferably 50% by weight or more.

The low molecular weight compound used in the electrolyte of the present invention preferably contains a cyclic carbonate. The cyclic carbonate is preferably 20% by weight or more, more preferably 30% by weight or more, still more preferably 40% by weight or more, based on the total weight of the low molecular weight compound. Particularly preferred is 0% by weight or more. Most preferred as cyclic carbonate is propylene carbonate, propylene. Carbonates and mixtures thereof.

The electrolyte of the present invention containing the low molecular weight compound as described above and the above oxocarbons is [substance amount of oxocarbons (mmo 1)] / [weight of low molecular weight compound (g) + Bonn weight (g)], that is, the equivalent amount of oxocarbons in the electrolyte is usually 0.05 to 8 mmo 1 Zg, preferably 0.1 to 7 mmol lZg, more preferably 0.3 to 6 mmo. 1 / g, most preferably 0.5-5mmo 1 Zg.

Here, if the equivalent of oxocarbons in the electrolyte is less than 0.05 mmo lZg, the ionic conductivity tends to decrease, which is not preferable in terms of power generation characteristics, and if it exceeds 8 mmo 1 ng, it dissolves in the solvent. There is a tendency for components that cannot be fully deposited to precipitate.

The oxocarbons are usually used so that the equivalent of the oxocarbons in the electrolyte falls within the above range. The equivalent of oxocarbons in the electrolyte of the present invention is determined using the NMR method.

The electrolyte of the present invention can be produced by mixing oxocarbons and a low molecular weight compound. When mixing, it may be at room temperature or heated below the boiling point of the low molecular compound. The heating temperature is preferably 150 ° C. or lower, more preferably 100 ° C. or lower.

The electrolyte of the present invention can be suitably used by impregnating a support with a mixture of oxocarbons and a low molecular weight compound. Examples of the carrier include porous materials, woven fabrics, non-woven fabrics, and the like. Specifically, materials composed of polymers typified by a separate evening described later, inorganic porous materials such as zeolite, molecular sieves, and porous glass. The material which consists of quality etc. is mentioned, The below-mentioned separate evening is especially preferable.

Next, a battery having the electrolyte of the present invention, particularly a lithium secondary battery will be described as an example of a secondary battery. The lithium secondary battery of the present invention generally has a positive electrode sheet, a negative electrode sheet, a separator, and the electrolyte of the present invention.

The positive electrode sheet usually has a mixture containing a positive electrode active material, a conductive material and a binder on the current collector. The one supported on is used. Specifically, as the positive electrode active material, a material containing a material capable of doping and detaching lithium ions, a material containing a carbonaceous material as a conductive material, and a material containing a thermoplastic resin as a binder are used. be able to. Examples of the material capable of doping and dedoping lithium ions include lithium composite oxides containing at least one transition metal such as V, Mn, Fe, Co, and Ni. Of these preferred details, in that the average discharge potential is high, lithium nickel acid, lithium composite oxide having an N a F E_〇 ₂ type structure, such as cobalt oxide lithium © beam, a spinel structure such as lithium cartoon Nsupineru And lithium composite oxide. The lithium composite oxide may contain various metal elements, particularly Ti, V, Cr, Mn, Fe, Co, Cu, Ag, Mg, Al, Ga, I. The at least one metal element is 0 with respect to the sum of the number of moles of at least one metal element selected from the group consisting of n and Sn and the number of moles of Ni in lithium nickelate. It is preferable to use a composite lithium nickelate containing the metal element so that the amount is 1 to 20 mol% because cycleability in use at a high capacity is improved.

As the binder, a thermoplastic resin is used. Specifically, polyvinylidene fluoride, vinylidene fluoride copolymer, polytetrafluoroethylene, tetrafluoroethylene monohexafluoropropylene, and the like are used. Polymer, copolymer of tetrafluoroethylene-perfluoroalkyl vinyl ether, copolymer of ethylene-tetrafluoroethylene, copolymer of vinylidenefluoride hexafluoropropylene-tetrafluoroethylene, thermoplastic Examples include thermoplastic resins such as polyimide, polyethylene, and polypropylene.

Examples of the conductive agent include carbonaceous materials such as natural graphite, artificial graphite, coke, and force pump rack. As the conductive material, each may be used alone, for example, artificial graphite and carbon black may be mixed and used.

As the positive electrode current collector, Al, Ni, stainless steel or the like can be used, and A 1 is preferable in that it is easy to process into a thin film and is inexpensive. As a method for supporting the mixture containing the positive electrode active material on the positive electrode current collector, a pressure molding method, a solvent, or the like is used. A paste or solution, and coating and drying on a current collector. In the latter method of coating and drying using a solvent, a method of pressing and fixing after drying can also be used.

As the negative electrode sheet, for example, a material capable of doping and dedoping lithium ions, lithium metal or lithium alloy can be used. Materials that can be doped and removed from lithium ions include natural graphite, artificial graphite, cokes, car pump racks, pyrolytic carbons, carbon fibers, and burned organic polymer compounds, and positive electrodes In addition, chalcogen compounds such as oxides and sulfides that dope / de-dope lithium ions at a low potential.

As a carbonaceous material, the main component is a graphite material such as natural graphite or artificial black lead, because it has a high potential flatness and a low average discharge potential, so when combined with a positive electrode, a large energy density can be obtained. A carbonaceous material is preferred.

As the negative electrode current collector, Cu, Ni, stainless steel and the like can be used. In particular, in a lithium secondary battery, Cu is preferable because it is difficult to form an alloy with lithium and it is easy to process into a thin film. The negative electrode current collector may be loaded with a mixture containing a negative electrode active material by a method of pressure molding, or by pasting into a paste using a solvent or the like and applying and drying on the current collector, followed by pressing. Is mentioned.

The separator can be made of a material such as fluororesin, polyethylene resin such as polyethylene, polypropylene, nylon, aromatic amide, and the like, and has a form such as a porous membrane, a nonwoven fabric, and a woven fabric. The thickness of the separation overnight is preferably as thin as possible as long as the mechanical strength is maintained, from the viewpoint that the volume energy density of the battery increases and the internal resistance decreases, and is preferably about 10 to 200. The shape of the lithium battery using the positive electrode active material for the secondary battery of the present invention is not particularly limited, and may be any of a paper type, a coin type, a cylindrical type, a rectangular type, and the like. EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. The lithium ion conductivity was measured at 25 ° C in a dry air atmosphere using a conductivity meter (CM-2 OS) manufactured by Toa Denpa Kogyo Co., Ltd., CELL TYPE: CG-51 1 B (cell constant: 0.983). Measurements were taken at C. (Reference Example 1)

3-Hydroxy-1 4 _Fenilu 3-Synthesis of 3-cyclobutene-1,2-dione (I)

In accordance with the method described in J ou rna lof Organic Chemi stry, 1988, 5 3 (1 1), 2482, 3_ (1-Methyloxy) —4—Phenol, 3-cyclobutene, 1, 2-Dione was produced. Next, 2.50 g of this product, 55 ml of THF 20m 1 12 N hydrochloric acid 55 ml were put into a 100 ml flask and stirred at 100 ° C for 5 hours. Then, it is allowed to cool to room temperature, the aqueous layer is washed with black mouth form, and then the aqueous layer is concentrated to give 3-hydroxy-4 1-phenyl 2-cyclobutene-1,2-dione (I) 1.38. g got. The structure was confirmed by ¹ H NMR and ¹³ C NMR. When 15 mg of the obtained (I) was dissolved in 3.0 ml of water, PH = 1.3 was shown.

(Example 1)

Prepare a homogeneous solution by adding 1.042 g (5.98 3 mmo 1), lithium hydroxide monohydrate 251.2 mg (5,986 mmol), methanol 10 ml 1 prepared in Reference Example 1 above to a 100 ml flask. It was. After evaporating methanol in the evaporator, it was vacuum-dried at room temperature for 1 hour, and further vacuum-dried at 15 Ot for 5 h to give 3-lithium 4 monophenyl 3-cyclobutene-1, 2-dione (II) 1.07 7 g was obtained. The structure was confirmed by ¹ H NMR. When 15 mg of the obtained (II) was sampled and dissolved in 3.0 ml of deionized water, ρΗ == 6.5. The resulting (II) 1.062 g was dissolved in 5.0 ml of dehydrated propylene, and dried with molecular sieve 3 A (1Z16) for 12 hours to obtain electrolyte (A). Got. In (A), the equivalent of oxo force was 0.852 mmo 1 / g. Table 1 shows the results of the conductivity measurement for (A).

(Example 2)

An electrolyte (B) was obtained in the same manner as in Example 1 except that the amount of propylene carbonate was changed to 10 ml. The equivalent of oxocarbon in (B) was 0.461 mmol / g. Table 1 shows the results of conductivity measurement for (B).

(Example 3)

An electrolyte (C) was obtained in the same manner as in Example 1 except that the amount of propylene carbonate was changed to 15 ml. The equivalent of oxocarbon in (C) was 0.316 mmol lZg. Table 1 shows the results of conductivity measurement for (C).

(Example 4)

An electrolyte (D) was obtained in the same manner as in Example 1 except that the amount of (II) was 0.531 g, and the amount of propylene strength monoponate was 20 ml. In (D), the equivalent of oxo force was 0.148 mmo 1 / g. Table 1 shows the results of conductivity measurement for (D).

(Reference Example 2)

4-Ritoxy _ 3— (Pen Yu fluorophenyl)

—Synthesis of dione (III)

Bromopentafluorobenzene (2.47 g, 10.0 mm o 1) and 30 ml of THF were placed in a flask to make a homogeneous solution. Keep this solution at 78 ° C n

—4.0 ml (10. Ommo 1) of butyllithium in hexane (2.5 M) was added and stirred for 30 minutes. This solution is referred to as Solution A. In a separate flask 3,

4-diisopropoxy-1-cyclobutene-1,2-dione 1.98 g (10.

Ommo 1) and THF 2 Om 1 were added to make a homogeneous solution and kept at 78 ° C. this The solution is referred to as Solution B.

Solution A was transferred to Solution B and stirred at 78 ° C for 2 hours. Thereafter, 5 ml of 2N hydrochloric acid was added to stop the reaction, and after bringing to room temperature, 200 ml of water was added. Extraction with ether was performed, and the oil layer was dried with magnesium sulfate. Evaporate the solvent in an evaporator and purify on a silica gel column (solvent: initial hexane / ether = 3/1, later methanol was used) 1.30 g (49%) of 4-hydroxy- 3- (Pentafluorophenyl) cyclobut-3-ene-1,2-dione was obtained. The structure was confirmed by ¹ H-NMR and ¹⁹ F-NMR.

4-Hydroxy-3- (pentafluorophenyl) cyclobutane 3-ene-1,2-dione 1.20 g (4.54 mmo 1), lithium hydroxide monohydrate 190.5 mg (4.54 mmo 1) and methanol in a flask To make a homogeneous solution. After confirming neutrality in the moistened pH test, the solvent was distilled off, followed by drying under reduced pressure with a vacuum pump at 60 ° C for 8 h. 4-Ritoxy-3- (pentafluorophenyl) cyclobuta 3 -Yen-1,2-dione (III) 1.22 g (4.54 mmo 1) was obtained.

(Example 5)

0.7120 g of (III) was weighed and dissolved in 3.5 ml of dehydrated propylene carbonate, and dried with molecular sieve 3A (1/16) for 12 hours to obtain an electrolyte (E). The equivalent of oxocarbon in (E) was 0.542 mmo1 / g. Table 1 shows the results of conductivity measurements for (E).

(Example 6)

An electrolyte (F) was obtained in the same manner as in Example 5 except that the amount of propylene carbonate was changed to 7 ml. The equivalent of oxocarbon in (F) was 0.292 mmolZg. Table 1 shows the results of conductivity measurements for (F). (Example 7)

An electrolyte (G) was obtained in the same manner as in Example 5 except that the amount of propylene carbonate was changed to 10.5 ml. The equivalent of oxocarbon in (G) was 0.200 mm o 1 / g. Table 1 shows the results of conductivity measurements for (G). table 1

The electrolyte containing the oxocarbons and the low-molecular compound of the present invention is applied to a battery such as a secondary battery, a fuel battery, an air battery, a solar battery, a capacitor, a capacitor, a sensor, an element, and an overnight. However, it is particularly useful as a lithium-ion conductive electrolyte for lithium secondary batteries. In particular, the electrolyte of the present invention is practical because it not only has lithium conductivity comparable to an electrolyte composed of an inorganic salt and an organic compound, but also has excellent chemical stability and can maintain high lithium conductivity for a long time. This is also advantageous.

Claims

The scope of the claims

1. An electrolyte containing oxocarbons and a low molecular weight compound having a molecular weight of less than 1000. 2. The electrolyte according to claim 1, wherein the oxocarbons are represented by the following formula (1).

(In the formula, X ¹ and X ² each independently represent 0_, — S— or — NR ′ —, Z represents one CO—, one C (S) one, -C (N ′ ′) one, substitution Represents an alkylene group having 1 to 6 carbon atoms which may have a group or an arylene group having 6 to 10 carbon atoms which may have a substituent, n represents the number of repetitions, and 0 to 10 N may be the same as or different from each other, and R may have one OH, one SH, -NHR ''', or a substituent. R 1 represents an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms which may have a substituent, or an aralkyl group having 7 to 16 carbon atoms which may have a substituent. R ′ and R ′ ′ ′ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an optionally substituted carbon group having 6 to 10 carbon atoms. B represents water It represents an atom or a monovalent metal atom.)

3. The electrolyte according to claim 2, wherein Z is one of _C (O), C (S) — or — C (NH).

4. The electrolyte according to claim 2, wherein X ¹ and X ^{2 are} −0—Z is —CO—, and n is an integer of 0 to 2.

5. The electrolyte according to claim 2, wherein B is selected from a hydrogen atom, a lithium atom, a sodium atom, a potassium atom, and a cesium atom. 6. The electrolyte according to claim 1, wherein the low molecular weight compound is a compound that exhibits a liquid state at 25 ° C. .

7. The electrolyte according to claim 1, wherein the low molecular compound is aprotic. 8. The electrolyte according to claim 1, wherein the low molecular compound is a low molecular compound having a dielectric constant of 50 or more.

9. The electrolyte according to claim 1, wherein the low molecular compound is a cyclic carbonate. 10. The electrolyte according to claim 1, wherein the low molecular weight compound is one or both of ethylene carbonate and propylene carbonate.

1 1. The amount of [oxocarbons (mmo 1)] / [weight of low molecular weight compound (g) + weight of oxocarbons (g)] is 0.05 to 8 mmo 1 / g. Electrolytes.

12. A battery comprising the electrolyte according to any one of claims 1 to 11. 13. The battery according to claim 12, wherein the battery is a lithium secondary battery.