JP5066807B2 - Lithium secondary battery electrolyte and lithium secondary battery - Google Patents

Description

The present invention relates to a lithium secondary battery using the same electrolyte and a lithium secondary battery containing a solvent.

  In recent years, many portable electronic devices such as a camera-integrated VTR (Videotape Recorder), a digital still camera, a mobile phone, a portable information terminal, or a notebook personal computer have appeared, and the size and weight of the portable electronic device have been reduced. Accordingly, development of secondary batteries that are lightweight and can obtain a high energy density as a power source for these electronic devices is underway. Among them, lithium secondary batteries are widely put into practical use because they can obtain a larger energy density than conventional lead batteries and nickel cadmium batteries.

In such lithium secondary batteries, an electrolyte obtained by dissolving LiPF ₆ as an electrolyte salt in a carbonate non-aqueous solvent such as propylene carbonate or diethyl carbonate is widely used because it has high conductivity and is also stable in potential. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 3-129664

  However, as portable electronic devices are increasingly used, recently, they are often placed under high temperature conditions during transportation or use, resulting in a problem of deterioration of battery characteristics. Therefore, there has been a demand for the development of an electrolyte or a battery that can obtain not only characteristics at room temperature but also excellent characteristics at high temperatures.

The present invention has been made in view of such problems, and an object thereof is to provide an electrolyte for a lithium secondary battery capable of improving high-temperature characteristics and a lithium secondary battery using the same.

The electrolyte for a lithium secondary battery of the present invention contains a solvent containing sultam shown in Chemical Formula 1.

The lithium secondary battery of the present invention includes an electrolyte together with a positive electrode and a negative electrode, and the electrolyte contains a solvent containing sultam shown in Chemical Formula 2.

According to the lithium secondary battery electrolyte of the present invention, since the sultam shown in Chemical Formula 1 is included, chemical stability can be improved even at high temperatures. Therefore, according to the lithium secondary battery of the present invention using this electrolyte, the decomposition reaction of the electrolyte can be suppressed even at high temperatures, and excellent characteristics can be obtained even when left under high temperature conditions. .

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 shows a cross-sectional configuration of a secondary battery according to an embodiment of the present invention. This secondary battery is a so-called lithium ion secondary battery in which lithium is used as an electrode reactant and the capacity of the negative electrode is represented by a capacity component due to insertion and extraction of lithium. This secondary battery is a so-called cylindrical type, and is a wound electrode in which a strip-like positive electrode 21 and a negative electrode 22 are laminated and wound inside a substantially hollow cylindrical battery can 11 via a separator 23. It has a body 20. The battery can 11 is made of, for example, iron (Fe) plated with nickel (Ni), and has one end closed and the other end open. Inside the battery can 11, a pair of insulating plates 12 and 13 are arranged perpendicular to the winding peripheral surface so as to sandwich the winding electrode body 20.

  At the open end of the battery can 11, a battery lid 14, a safety valve mechanism 15 provided inside the battery lid 14 and a heat sensitive resistance element (Positive Temperature Coefficient; PTC element) 16 are interposed via a gasket 17. It is attached by caulking, and the inside of the battery can 11 is sealed. The battery lid 14 is made of, for example, the same material as the battery can 11. The safety valve mechanism 15 is electrically connected to the battery lid 14 via the heat sensitive resistance element 16, and the disk plate 15A is reversed when the internal pressure of the battery exceeds a certain level due to an internal short circuit or external heating. Thus, the electrical connection between the battery lid 14 and the wound electrode body 20 is cut off. When the temperature rises, the heat sensitive resistance element 16 limits the current by increasing the resistance value and prevents abnormal heat generation due to a large current. The gasket 17 is made of, for example, an insulating material, and asphalt is applied to the surface.

  For example, a center pin 24 is inserted in the center of the wound electrode body 20. A positive electrode lead 25 made of aluminum (Al) or the like is connected to the positive electrode 21 of the spirally wound electrode body 20, and a negative electrode lead 26 made of nickel or the like is connected to the negative electrode 22. The positive electrode lead 25 is electrically connected to the battery lid 14 by being welded to the safety valve mechanism 15, and the negative electrode lead 26 is welded to and electrically connected to the battery can 11.

  FIG. 2 shows an enlarged part of the spirally wound electrode body 20 shown in FIG. The positive electrode 21 includes, for example, a positive electrode current collector 21A having a pair of opposed surfaces and a positive electrode active material layer 21B provided on both surfaces or one surface of the positive electrode current collector 21A. The positive electrode current collector 21A is made of a metal material such as aluminum, nickel, or stainless steel, for example. The positive electrode active material layer 21B includes, for example, a positive electrode material that can occlude and release lithium as a positive electrode active material.

As a cathode material capable of inserting and extracting lithium, for example, lithium cobalt oxide, a solid solution containing lithium nickelate, or these _{(Li (Ni x Co y Mn} z) O 2)) (x, y and z Of 0 <x <1, 0 <y <1, 0 <z <1, x + y + z = 1), or lithium composite oxide such as manganese spinel (LiMn ₂ O ₄ ), or lithium iron phosphate A phosphate compound having an olivine structure such as (LiFePO ₄ ) is preferred. This is because a high energy density can be obtained. Examples of positive electrode materials capable of inserting and extracting lithium include oxides such as titanium oxide, vanadium oxide and manganese dioxide, disulfides such as iron disulfide, titanium disulfide and molybdenum sulfide, polyaniline or Examples also include conductive polymers such as polythiophene. As the positive electrode material, one kind may be used alone, or two or more kinds may be mixed and used.

  The positive electrode active material layer 21 </ b> B also includes, for example, a conductive material, and may further include a binder as necessary. Examples of the conductive material include carbon materials such as graphite, carbon black, and ketjen black, and one or more of them are used in combination. In addition to the carbon material, a metal material or a conductive polymer material may be used as long as it is a conductive material. Examples of the binder include synthetic rubbers such as styrene butadiene rubber, fluorine rubber or ethylene propylene diene rubber, or polymer materials such as polyvinylidene fluoride, and one or more of them are mixed. Used. For example, when the positive electrode 21 and the negative electrode 22 are wound as shown in FIG. 1, it is preferable to use a styrene butadiene rubber or a fluorine rubber having high flexibility as the binder.

  The negative electrode 22 includes, for example, a negative electrode current collector 22A having a pair of opposed surfaces, and a negative electrode active material layer 22B provided on both surfaces or one surface of the negative electrode current collector 22A.

  The negative electrode 22 has, for example, a structure in which a negative electrode active material layer 22B is provided on both surfaces of a negative electrode current collector 22A having a pair of opposed surfaces. The anode current collector 22A is made of, for example, a metal material such as copper (Cu), nickel, or stainless steel.

  The negative electrode active material layer 22B includes, for example, any one or more of negative electrode materials capable of inserting and extracting lithium as a negative electrode active material.

  In this secondary battery, the charge capacity of the negative electrode material capable of inserting and extracting lithium is larger than the charge capacity of the positive electrode 21 so that lithium metal does not deposit on the negative electrode 22 during the charge. It has become.

  Examples of the negative electrode material capable of inserting and extracting lithium include a material containing tin or silicon as a constituent element. This is because tin and silicon have a large ability to occlude and release lithium, and a high energy density can be obtained.

  As such a negative electrode material, specifically, a simple substance, an alloy, or a compound of tin, a simple substance, an alloy, or a compound of silicon, or a material having one or more phases thereof at least in part. Is mentioned. In the present invention, alloys include those containing one or more metal elements and one or more metalloid elements in addition to those composed of two or more metal elements. Moreover, the nonmetallic element may be included. There are structures in which a solid solution, a eutectic (eutectic mixture), an intermetallic compound, or two or more of them coexist.

  As an alloy of tin, for example, as the second constituent element other than tin, silicon, nickel, copper, iron, cobalt (Co), manganese (Mn), zinc (Zn), indium (In), silver (Ag) , Titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb), and chromium (Cr). As an alloy of silicon, for example, as a second constituent element other than silicon, among the group consisting of tin, nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium, germanium, bismuth, antimony and chromium The thing containing at least 1 sort (s) of these is mentioned.

  Examples of the tin compound or silicon compound include those containing oxygen or carbon, and may contain the second constituent element described above in addition to tin or silicon.

  Among these, as this negative electrode material, tin, cobalt, and carbon are included as constituent elements, the carbon content is 9.9 mass% or more and 29.7 mass% or less, and the total of tin and cobalt is A CoSnC-containing material having a cobalt ratio Co / (Sn + Co) of 30% by mass to 70% by mass is preferable. This is because a high energy density can be obtained in such a composition range, and excellent cycle characteristics can be obtained.

  This CoSnC-containing material may further contain other constituent elements as necessary. As other constituent elements, for example, silicon, iron, nickel, chromium, indium, niobium (Nb), germanium, titanium, molybdenum (Mo), aluminum, phosphorus (P), gallium (Ga) or bismuth is preferable. It may contain more than seeds. This is because the capacity or cycle characteristics can be further improved.

  This CoSnC-containing material has a phase containing tin, cobalt, and carbon, and this phase preferably has a low crystallinity or an amorphous structure. In this CoSnC-containing material, it is preferable that at least a part of carbon as a constituent element is bonded to a metal element or a semimetal element as another constituent element. The decrease in cycle characteristics is thought to be due to the aggregation or crystallization of tin or the like, but this is because such aggregation or crystallization can be suppressed by combining carbon with other elements. .

  As a measuring method for examining the bonding state of elements, for example, X-ray photoelectron spectroscopy (XPS) can be cited. In XPS, the peak of the carbon 1s orbital (C1s) appears at 284.5 eV in an energy calibrated apparatus so that the peak of the gold atom 4f orbital (Au4f) is obtained at 84.0 eV if it is graphite. . Moreover, if it is surface contamination carbon, it will appear at 284.8 eV. On the other hand, when the charge density of the carbon element increases, for example, when carbon is bonded to a metal element or a metalloid element, the C1s peak appears in a region lower than 284.5 eV. That is, when the peak of the synthetic wave of C1s obtained for the CoSnC-containing material appears in a region lower than 284.5 eV, at least a part of the carbon contained in the CoSnC-containing material is a metal element or a half of other constituent elements. Combined with metal elements.

  In XPS measurement, for example, the C1s peak is used to correct the energy axis of the spectrum. Usually, since surface-contaminated carbon exists on the surface, the C1s peak of the surface-contaminated carbon is set to 284.8 eV, which is used as an energy standard. In the XPS measurement, the waveform of the C1s peak is obtained as a shape including the surface contamination carbon peak and the carbon peak in the CoSnC-containing material. For example, by analyzing using a commercially available software, the surface contamination The carbon peak and the carbon peak in the CoSnC-containing material are separated. In the waveform analysis, the position of the main peak existing on the lowest bound energy side is used as the energy reference (284.8 eV).

  As a negative electrode material capable of inserting and extracting lithium, for example, a material containing another metal element or other metalloid element capable of forming an alloy with lithium as a constituent element can also be used. Such metal elements or metalloid elements include magnesium (Mg), boron (B), aluminum, gallium, indium, germanium, lead (Pb), bismuth, cadmium (Cd), silver, zinc, hafnium (Hf). , Zirconium (Zr), yttrium (Y), palladium (Pd), or platinum (Pt).

  Examples of the negative electrode material capable of inserting and extracting lithium also include a carbon material capable of inserting and extracting lithium. Examples of such carbon materials include non-graphitizable carbon, graphitizable carbon, graphite, pyrolytic carbons, cokes, graphites, glassy carbons, organic polymer compound fired bodies, carbon fibers, and activated carbon. . Among these, cokes include pitch coke, needle coke, and petroleum coke. Organic polymer compound fired bodies are carbonized by firing polymer compounds such as phenol resin and furan resin at an appropriate temperature. What you did. In addition, such a carbon material has very little change in crystal structure due to insertion and extraction of lithium, and when used with the negative electrode material described above, a high energy density can be obtained and excellent cycle characteristics can be obtained. This is preferable because it also functions as a conductive material.

  Examples of the negative electrode material capable of inserting and extracting lithium further include metal oxides or polymer compounds capable of inserting and extracting lithium. Examples of the metal oxide include iron oxide, ruthenium oxide, and molybdenum oxide, and examples of the polymer compound include polyacetylene and polypyrrole.

  The separator 23 is made of, for example, a porous film made of synthetic resin such as polytetrafluoroethylene, polypropylene, or polyethylene, or a porous film made of ceramic, and has a structure in which two or more kinds of porous films are laminated. May be. Among these, a porous film made of polyolefin is preferable because it is excellent in short-circuit preventing effect and can improve the safety of the battery due to the shutdown effect. In particular, polyethylene is preferable as a material constituting the separator 23 because a shutdown effect can be obtained within a range of 100 ° C. or higher and 160 ° C. or lower and the electrochemical stability is excellent. Polypropylene is also preferable, and any other resin having chemical stability can be used by copolymerizing or blending with polyethylene or polypropylene.

  For example, the separator 23 is impregnated with an electrolytic solution that is a liquid electrolyte. The electrolytic solution contains, for example, a solvent and an electrolyte salt dissolved in the solvent.

  The solvent contains the sultam shown in Chemical formula 3. Thereby, the chemical stability of the electrolyte can be improved even at high temperatures, and the decomposition reaction of the electrolyte can be suppressed. Therefore, excellent characteristics can be obtained even when left under high temperature conditions. One kind of sultam may be used alone, or a plurality of kinds may be mixed and used.

（Ｘ１は、酸素，窒素または炭素を表す。Ｒ１は、ビニレン基、または炭素数が１から１０の直鎖状あるいは分岐状のアルキレン基，またはそれらの少なくとも一部の水素をアリル基，ビニル基，アリール基，アルコキシ基およびハロゲン基からなる群のうちの少なくとも１種で置換した基を表す。但し、Ｒ１がビニレン基の場合には、Ｘ１は炭素である。Ｒ２は、アルキル基，アリル基，アリール基，複素環基，アラルキル基，アルコキシアルキル基，またはそれらの少なくとも一部の水素をハロゲンで置換した基を表す。）

(X1 represents oxygen, nitrogen or carbon. R1 represents a vinylene group, a linear or branched alkylene group having 1 to 10 carbon atoms, or at least a part of hydrogen atoms as an allyl group or vinyl group. Represents a group substituted with at least one selected from the group consisting of an aryl group, an alkoxy group and a halogen group, provided that when R1 is a vinylene group, X1 is carbon, and R2 is an alkyl group or an allyl group. , An aryl group, a heterocyclic group, an aralkyl group, an alkoxyalkyl group, or a group obtained by substituting at least a part of hydrogen with a halogen.

  Specific examples of such sultams include compounds shown in Chemical Formula 4 below.

  The content of sultam shown in Chemical Formula 3 is preferably 0.01% by mass or more and 15% by mass or less, and more preferably 0.01% by mass or more and 10% by mass or less in the solvent. If it is within this range, it is possible to obtain more excellent characteristics even when left under high temperature conditions. In particular, if it is 10% by mass or less, excellent characteristics can be obtained even when used under high temperature conditions. Because you can.

  In addition to these sultams, the solvent preferably contains a cyclic carbonate derivative having a halogen atom, and among them, the cyclic carbonate derivative shown in Chemical Formula 5 is desirable. This is because the decomposition reaction of the electrolytic solution can be suppressed even at high temperatures, and the battery characteristics can be further improved. A cyclic carbonate derivative may be used individually by 1 type, and may mix and use multiple types.

（Ｒ３，Ｒ４，Ｒ５およびＲ６は、メチル基，エチル基あるいはそれら少なくとも一部の水素（Ｈ）をフッ素基若しくは塩素基で置換した基、または水素基、またはフッ素基、または塩素基を表す。Ｒ３，Ｒ４，Ｒ５およびＲ６のうちの少なくとも一つはハロゲンを有する基である。Ｒ３，Ｒ４，Ｒ５およびＲ６は、同一のものがあっても、すべてが異なっていてもよい。）

(R3, R4, R5 and R6 each represents a methyl group, an ethyl group, a group in which at least a part of hydrogen (H) is substituted with a fluorine group or a chlorine group, a hydrogen group, a fluorine group, or a chlorine group. (At least one of R3, R4, R5 and R6 is a group having a halogen. R3, R4, R5 and R6 may be the same or all different.)

  Specific examples of the cyclic carbonate derivative shown in Chemical formula 5 are shown in Chemical formulas (1-1) to (1-14) and Chemical formula 7 (1-15) to (1-23). Compounds. Among these, 4-fluoro-1,3-dioxolan-2-one shown in (1-1) of Chemical Formula 7 is preferable. This is because a higher effect can be obtained.

  As the solvent, a cyclic carbonate of an unsaturated compound is also preferable. This is because the battery characteristics at a high temperature can be further improved. Specific examples of the unsaturated carbonate cyclic ester include 1,3-dioxol-2-one and 4-vinyl-1,3-dioxolan-2-one. The cyclic ester carbonate of an unsaturated compound may be used alone or in combination of two or more.

  In addition to these, the solvent includes various conventionally used solvents such as ethylene carbonate, propylene carbonate, butylene carbonate, γ-butyrolactone, γ-valerolactone, 1,2-dimethoxyethane, tetrahydrofuran. 2-methyltetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, methyl acetate, methyl propionate, ethyl propionate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, acetonitrile, glutaronitrile, adiponitrile , Methoxyacetonitrile, 3-methoxypropionitrile, N, N-dimethylformamide, N-methylpyrrolidinone, N-methyloxazolidinone, N, N'-dimethylimidazolidinone, nitromethane, nitroethane, sulfolane, dimethylsulfur Examples include oxide and trimethyl phosphate. Among these, in order to realize excellent charge / discharge capacity characteristics and charge / discharge cycle characteristics, it is preferable to use at least one selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, and ethyl methyl carbonate. Other solvents may be used alone or in combination of two or more.

Examples of the electrolyte salt include LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) _2, or LiN (C ₄ F ₉ SO ₂ ) (CF ₃ Lithium salt shown in Chemical formula 8 such as SO ₂ ), or Lithium salt shown in Chemical formula 9 such as LiC (CF ₃ SO ₂ ) ₃ , Cyclic imide salt shown in Chemical formula 10, Cyclic imide shown in Chemical formula 11 Preferable examples include salts or light metal salts shown in Chemical formula 12, particularly LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , lithium salt shown in Chemical formula 8, lithium salt shown in Chemical formula ₉ , and chemical formula 10 It is preferable to use a mixture of at least one member selected from the group consisting of a cyclic imide salt, a cyclic imide salt shown in Chemical Formula 11 and a light metal salt shown in Chemical Formula 12. This is because the ion conductivity can be improved, the decomposition reaction of the electrolytic solution can be further suppressed even at a high temperature, and the battery characteristics can be further improved.

（ｍおよびｎは、１以上の整数である。）

(M and n are integers of 1 or more.)

（ｐ，ｑおよびｒは、１以上の整数である）

(P, q and r are integers of 1 or more)

（Ｍ１は短周期型周期表における１Ａ族元素，２Ａ族元素またはアルミニウムを表す。Ｒ７は、炭素数２から５の直鎖状あるいは分岐状のアルキレン基、またはそれらの少なくとも一部の水素をフッ素（Ｆ）で置換した基を表す。ｔは、１, ２または３である。）

(M1 represents a group 1A element, a group 2A element or aluminum in the short periodic table. R7 represents a linear or branched alkylene group having 2 to 5 carbon atoms, or at least a part of hydrogen atoms thereof as fluorine. Represents a group substituted with (F), t is 1, 2 or 3)

（Ｍ２は、短周期型周期表における１Ａ族元素，２Ａ族元素またはアルミニウムを表す。Ｒ８は、炭素数２から５の直鎖状あるいは分岐状のアルキレン基、またはそれらの少なくとも一部の水素をフッ素で置換した基を表す。ｕは、１, ２または３である。）

(M2 represents a group 1A element, a group 2A element or aluminum in the short periodic table. R8 represents a linear or branched alkylene group having 2 to 5 carbon atoms, or at least a part of hydrogen atoms thereof. Represents a group substituted with fluorine, u is 1, 2 or 3)

（Ｒ１１は、化１３，化１４または化１５に示した基を表し、Ｒ１２は、ハロゲン基，アルキル基，ハロゲン化アルキル基，アリール基またはハロゲン化アリール基を表し、Ｘ１１およびＸ１２は、酸素または硫黄（Ｓ）をそれぞれ表し、Ｍ１１は、遷移金属元素または短周期型周期表における３Ｂ族元素，４Ｂ族元素あるいは５Ｂ族元素を表し、Ｍ２１は、短周期型周期表における１Ａ族元素あるいは２Ａ族元素またはアルミニウムを表し、ａは１から４の整数であり、ｂは０から８の整数であり、ｃ，ｄ，ｅおよびｆはそれぞれ１から３の整数である。）

(R11 represents the group shown in Chemical formula 13, Chemical formula 14 or Chemical formula 15, R12 represents a halogen group, an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group, and X11 and X12 are oxygen or S11 represents sulfur (S), M11 represents a transition metal element or a group 3B element, a group 4B element or a group 5B element in the short periodic table, and M21 represents a group 1A or group 2A in the short periodic table Represents an element or aluminum, a is an integer from 1 to 4, b is an integer from 0 to 8, and c, d, e, and f are each an integer from 1 to 3.)

（Ｒ２１は、アルキレン基，ハロゲン化アルキレン基，アリーレン基またはハロゲン化アリーレン基を表す。）

(R21 represents an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group.)

（Ｒ２２，Ｒ２３は、アルキル基，ハロゲン化アルキル基，アリール基またはハロゲン化アリール基を表す。Ｒ２２，Ｒ２３は、同一であっても異なっていてもよい。）

(R22 and R23 represent an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group. R22 and R23 may be the same or different.)

  Examples of the cyclic imide salt shown in Chemical formula 10 and the cyclic imide salt shown in Chemical formula 11 include 1,2-perfluoroethanedisulfonylimide lithium shown in Chemical formula 16 (1), and Chemical formula 16 (2). 1,3-perfluoropropanedisulfonylimide lithium shown, 1,3-perfluorobutanedisulfonylimide lithium shown in Chemical formula 16 (3), 1,4-perfluorobutanedi shown in Chemical formula 16 (4) Examples thereof include sulfonylimidolithium and lithium perfluoroheptanenidate shown in Chemical formula 16 (5).

  As the light metal salt shown in Chemical formula 12, for example, the compound shown in Chemical formula 17 is preferable.

（Ｒ１１は、化１８，化１９または化２０に示した基を表し、Ｒ１３は、ハロゲン基を表し、Ｍ１２は、リン（Ｐ）またはホウ素を表し、Ｍ２１は短周期型周期表における１Ａ族元素あるいは２Ａ族元素またはアルミニウムを表し、ａ１は１から３の整数であり、ｂ１は０，２または４であり、ｃ，ｄ，ｅおよびｆはそれぞれ１から３の整数である。）

(R11 represents the group shown in Chemical formula 18, Chemical formula 19 or Chemical formula 20, R13 represents a halogen group, M12 represents phosphorus (P) or boron, and M21 represents a group 1A element in the short-period type periodic table. Alternatively, it represents a group 2A element or aluminum, a1 is an integer from 1 to 3, b1 is 0, 2 or 4, and c, d, e and f are each an integer from 1 to 3.)

（Ｒ２１は、アルキレン基，ハロゲン化アルキレン基，アリーレン基またはハロゲン化アリーレン基を表す。）

(R21 represents an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group.)

（Ｒ２２，Ｒ２３は、アルキル基，ハロゲン化アルキル基，アリール基またはハロゲン化アリール基を表す。Ｒ２２，Ｒ２３は、同一であっても異なっていてもよい。）

(R22 and R23 represent an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group. R22 and R23 may be the same or different.)

  Specifically, difluoro [oxolato-O, O ′] lithium borate shown in Chemical Formula 21, lithium tetrafluoro [oxolato-O, O ′] lithium phosphate shown in Chemical Formula 22, and difluorobis [ Oxolato-O, O ′] lithium phosphate, difluoro [3,3,3-trifluoro-2-oxide-2-trifluoromethylpropionate (2-)-O, O ′] boric acid shown in Chemical Formula 24 Lithium, bis [3,3,3-trifluoro-2-oxide-2-trifluoromethylpropionate (2-)-O, O ′] lithium borate shown in Chemical Formula 25, and bis shown in Chemical Formula 26 [Oxolato-O, O ′] lithium borate and the like.

Besides these, electrolyte salts include LiB (C ₆ H ₅ ) ₄ , LiCH ₃ SO ₃ , LiCF ₃ SO ₃ , LiAlCl ₄ , LiSiF ₆ , LiCl, or LiBr.

  The content (concentration) of the electrolyte salt is preferably in the range of 0.3 mol / kg or more and 3.0 mol / kg or less with respect to the solvent. Outside this range, there is a risk that sufficient battery characteristics may not be obtained due to an extreme decrease in ionic conductivity. Among them, the content of the light metal salt shown in Chemical formula 12 is preferably in the range of 0.01 mol / kg to 2.0 mol / kg with respect to the solvent. This is because a higher effect can be obtained within this range.

  For example, the secondary battery can be manufactured as follows.

  First, for example, the positive electrode active material layer 21B is formed on the positive electrode current collector 21A to produce the positive electrode 21. The positive electrode active material layer 21B is prepared, for example, by mixing a positive electrode active material powder, a conductive material, and a binder to prepare a positive electrode mixture, and then using the positive electrode mixture in a solvent such as N-methyl-2-pyrrolidone. The positive electrode mixture slurry is dispersed to form a positive electrode mixture slurry, and the positive electrode mixture slurry is applied to the positive electrode current collector 21A, dried, and compression molded. Further, for example, in the same manner as the positive electrode 21, the negative electrode active material layer 22 </ b> B is formed on the negative electrode current collector 22 </ b> A to produce the negative electrode 22.

  Next, the positive electrode lead 25 is attached to the positive electrode current collector 21A by welding or the like, and the negative electrode lead 26 is attached to the negative electrode current collector 22A by welding or the like. Subsequently, the positive electrode 21 and the negative electrode 22 are wound through the separator 23, and the tip of the positive electrode lead 25 is welded to the safety valve mechanism 15, and the tip of the negative electrode lead 26 is welded to the battery can 11. The positive electrode 21 and the negative electrode 22 are sandwiched between a pair of insulating plates 12 and 13 and stored in the battery can 11. After the positive electrode 21 and the negative electrode 22 are accommodated in the battery can 11, the electrolytic solution is injected into the battery can 11 and impregnated in the separator 23. After that, the battery lid 14, the safety valve mechanism 15, and the heat sensitive resistance element 16 are fixed to the opening end of the battery can 11 by caulking through a gasket 17. Thereby, the secondary battery shown in FIGS. 1 and 2 is completed.

  In the secondary battery, when charged, for example, lithium ions are extracted from the positive electrode 21 and inserted in the negative electrode 22 through the electrolytic solution. When discharging is performed, for example, lithium ions are released from the negative electrode 22 and inserted in the positive electrode 21 through the electrolytic solution. At that time, since the sultam shown in Chemical Formula 3 is contained in the electrolytic solution, the decomposition reaction of the electrolytic solution is suppressed even at a high temperature.

  Thus, according to the present embodiment, since the sultam shown in Chemical Formula 3 is included in the electrolytic solution, the chemical stability of the electrolytic solution can be improved even at high temperatures. Therefore, according to the secondary battery according to the present embodiment using this electrolytic solution, excellent characteristics can be obtained even when left under high temperature conditions.

Further, if the content of sultam shown in Chemical Formula 3 in the solvent is 0.01% by mass or more and 15% by mass or less, or if the electrolytic solution contains a cyclic carbonate derivative having a halogen atom. Alternatively, if a cyclic carbonate of an unsaturated compound is included, or LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , a lithium salt shown in Chemical Formula 8, a lithium salt shown in Chemical Formula 9, or a chemical formula shown in Chemical Formula 10 If the cyclic imide salt, the cyclic imide salt shown in Chemical Formula 11 or the light metal salt shown in Chemical Formula 12 is included, battery characteristics at high temperatures can be further improved.

(Second Embodiment)
The secondary battery according to the second embodiment of the present invention has the same configuration and operation as the secondary battery according to the first embodiment, except that the configuration of the negative electrode is different. It can be manufactured in the same manner. Therefore, with reference to FIG. 1 and FIG. 2, the same code | symbol is attached | subjected to a corresponding component and description of the same part is abbreviate | omitted.

  The negative electrode 22 has a structure in which a negative electrode active material layer 22B is provided on both surfaces of a negative electrode current collector 22A, similarly to the secondary battery according to the first embodiment. The negative electrode active material layer 22B contains, for example, a material containing tin or silicon as a constituent element as a negative electrode active material. Specifically, for example, it contains a simple substance, an alloy, or a compound of tin, or a simple substance, an alloy, or a compound of silicon, and may contain two or more of them.

  The negative electrode active material layer 22B is formed by using, for example, a vapor phase method, a liquid phase method, a thermal spraying method, a firing method, or two or more of these methods. The electrical conductor 22A is preferably alloyed at least at a part of the interface. Specifically, it is preferable that the constituent element of the negative electrode current collector 22A is diffused in the negative electrode active material layer 22B, the constituent element of the negative electrode active material is diffused in the negative electrode current collector 22A, or they are mutually diffused at the interface. This is because breakage due to expansion / contraction of the negative electrode active material layer 22B due to charging / discharging can be suppressed, and electronic conductivity between the negative electrode active material layer 22B and the negative electrode current collector 22A can be improved. .

  As the vapor phase method, for example, a physical deposition method or a chemical deposition method can be used. Specifically, a vacuum deposition method, a sputtering method, an ion plating method, a laser ablation method, a thermal chemical vapor deposition ( Examples include CVD (Chemical Vapor Deposition) and plasma enhanced chemical vapor deposition. As the liquid phase method, a known method such as electroplating or electroless plating can be used. The firing method is, for example, a method in which a particulate negative electrode active material is mixed with a binder, dispersed in a solvent, applied, and then heat-treated at a temperature higher than the melting point of the binder. A known method can also be used for the firing method, for example, an atmospheric firing method, a reactive firing method, or a hot press firing method.

(Third embodiment)
The secondary battery according to the third embodiment of the present invention is a so-called lithium metal secondary battery in which the capacity of the negative electrode is represented by a capacity component due to deposition and dissolution of lithium.

  This secondary battery has the same configuration and effects as the secondary battery according to the first or second embodiment except that the configuration of the negative electrode active material layer 22B is different. Therefore, with reference to FIG. 1 and FIG. 2, the same code | symbol is attached | subjected to a corresponding component and description of the same part is abbreviate | omitted.

  The negative electrode active material layer 22B is made of lithium metal that is a negative electrode active material, and can obtain a high energy density. The negative electrode active material layer 22B may be configured to be already provided from the time of assembly, but may be configured by lithium metal which is not present at the time of assembly and is deposited during charging. The negative electrode active material layer 22B may also be used as a current collector, and the negative electrode current collector 22A may be deleted.

  In this secondary battery, except that the negative electrode 22 is the negative electrode current collector 22A only, or the lithium metal only, or the negative electrode current collector 22A is bonded with a lithium metal foil to form the negative electrode active material layer 22B. Others can be manufactured in the same manner as the secondary battery according to the first embodiment.

  In this secondary battery, when charged, for example, lithium ions are released from the positive electrode 21 and deposited as lithium metal on the surface of the negative electrode current collector 22A via the electrolytic solution, as shown in FIG. Then, the negative electrode active material layer 22B is formed. When the discharge is performed, for example, lithium metal is eluted as lithium ions from the negative electrode active material layer 22B, and is occluded in the positive electrode 21 through the electrolytic solution. At that time, since the sultam shown in Chemical Formula 3 is contained in the electrolytic solution, the decomposition reaction of the electrolytic solution is suppressed even at a high temperature.

  Thus, also in the secondary battery of the third embodiment, since the sultam shown in Chemical Formula 3 is included in the electrolytic solution, excellent characteristics can be obtained even when left under high temperature conditions.

(Fourth embodiment)
FIG. 3 shows the configuration of the secondary battery according to the fourth embodiment. This secondary battery is a so-called laminate film type, and has a wound electrode body 30 to which a positive electrode lead 31 and a negative electrode lead 32 are attached accommodated in a film-shaped exterior member 40.

  The positive electrode lead 31 and the negative electrode lead 32 are led out from the inside of the exterior member 40 to the outside, for example, in the same direction. The positive electrode lead 31 and the negative electrode lead 32 are each made of a metal material such as aluminum, copper, nickel, or stainless steel, and each have a thin plate shape or a mesh shape.

  The exterior member 40 is made of, for example, a rectangular aluminum laminated film in which a nylon film, an aluminum foil, and a polyethylene film are bonded together in this order. For example, the exterior member 40 is disposed so that the polyethylene film side and the wound electrode body 30 face each other, and the outer edge portions are in close contact with each other by fusion bonding or an adhesive. An adhesive film 41 is inserted between the exterior member 40 and the positive electrode lead 31 and the negative electrode lead 32 to prevent intrusion of outside air. The adhesion film 41 is made of a material having adhesion to the positive electrode lead 31 and the negative electrode lead 32, for example, a polyolefin resin such as polyethylene, polypropylene, modified polyethylene, or modified polypropylene.

  The exterior member 40 may be made of a laminated film having another structure, a polymer film such as polypropylene, or a metal film instead of the above-described aluminum laminated film.

  FIG. 4 shows a cross-sectional structure taken along line II of the spirally wound electrode body 30 shown in FIG. The wound electrode body 30 is formed by stacking and winding a positive electrode 33 and a negative electrode 34 with a separator 35 and an electrolyte 36, and the outermost periphery is protected by a protective tape 37.

  The positive electrode 33 has a structure in which a positive electrode active material layer 33B is provided on both surfaces of a positive electrode current collector 33A. The negative electrode 34 has a structure in which a negative electrode active material layer 34B is provided on both surfaces of a negative electrode current collector 34A, and the negative electrode active material layer 34B and the positive electrode active material layer 33B are arranged to face each other. The configurations of the positive electrode current collector 33A, the positive electrode active material layer 33B, the negative electrode current collector 34A, the negative electrode active material layer 34B, and the separator 35 are the same as the positive electrode current collector 21A, the positive electrode active material in the first to third embodiments described above. This is the same as the material layer 21B, the negative electrode current collector 22A, the negative electrode active material layer 22B, and the separator 23.

  The electrolyte 36 has a so-called gel shape including the electrolytic solution described in the first embodiment and a polymer compound serving as a holding body that holds the electrolytic solution. A gel electrolyte is preferable because high ion conductivity can be obtained and battery leakage can be prevented. Examples of the polymer compound include, for example, an ether polymer compound such as polyethylene oxide or a crosslinked product containing polyethylene oxide, an ester polymer compound such as polymethacrylate, or an acrylate polymer compound, or polyvinylidene fluoride or vinylidene fluoride. Examples thereof include polymers of vinylidene fluoride such as a copolymer with hexafluoropropylene, and any one of these or a mixture of two or more thereof is used. In particular, from the viewpoint of redox stability, it is desirable to use a fluorine-based polymer compound such as a vinylidene fluoride polymer.

  The electrolyte 36 may be used as it is as a liquid electrolyte, instead of holding the electrolytic solution in the polymer compound. In this case, the electrolytic solution is impregnated in the separator 35.

  For example, the secondary battery can be manufactured as follows.

  First, a precursor solution containing an electrolytic solution, a polymer compound, and a mixed solvent is applied to each of the positive electrode 33 and the negative electrode 34, and the mixed solvent is volatilized to form the electrolyte 36. Next, the positive electrode lead 31 is attached to the positive electrode current collector 33A, and the negative electrode lead 32 is attached to the negative electrode current collector 34A. Subsequently, the positive electrode 33 and the negative electrode 34 on which the electrolyte 36 is formed are laminated through a separator 35 to form a laminated body, and then the laminated body is wound in the longitudinal direction, and a protective tape 37 is adhered to the outermost peripheral portion. Thus, the wound electrode body 30 is formed. After that, for example, the wound electrode body 30 is sandwiched between the exterior members 40, and the outer edge portions of the exterior members 40 are sealed and sealed by thermal fusion or the like. At that time, the adhesion film 41 is inserted between the positive electrode lead 31 and the negative electrode lead 32 and the exterior member 40. Thereby, the secondary battery shown in FIGS. 3 and 4 is completed.

  Further, this secondary battery may be manufactured as follows. First, the positive electrode 33 and the negative electrode 34 are prepared as described above, and after the positive electrode lead 31 and the negative electrode lead 32 are attached to the positive electrode 33 and the negative electrode 34, the positive electrode 33 and the negative electrode 34 are stacked via the separator 35 and wound. Rotate and adhere the protective tape 37 to the outermost periphery to form a wound body that is a precursor of the wound electrode body 30. Next, the wound body is sandwiched between the exterior members 40, and the outer peripheral edge portion excluding one side is heat-sealed to form a bag shape, and is stored inside the exterior member 40. Subsequently, an electrolyte composition including an electrolytic solution, a monomer that is a raw material of the polymer compound, and other materials such as a polymerization initiator or a polymerization inhibitor as necessary is prepared, and the interior of the exterior member 40 is prepared. After the injection, the opening of the exterior member 40 is heat-sealed and sealed. Thereafter, heat is applied to polymerize the monomer to form a polymer compound, thereby forming a gel electrolyte 36, and assembling the secondary battery shown in FIGS.

  The secondary battery operates in the same manner as the secondary batteries according to the first to third embodiments, and can obtain the same effects.

  Further, specific embodiments of the present invention will be described in detail.

( Experimental Examples 1-1 to 1-14)
The laminate film type secondary battery shown in FIGS. At that time, a so-called lithium ion secondary battery in which the capacity of the negative electrode was expressed by a capacity component due to insertion and extraction of lithium was produced. First, lithium carbonate (Li ₂ CO ₃ ) and cobalt carbonate (CoCO ₃ ) are mixed at a ratio of Li ₂ CO ₃ : CoCO ₃ = 0.5: 1 (molar ratio), and 5 ° C. at 900 ° C. in the air. After firing for a time, lithium-cobalt composite oxide (LiCoO ₂ ) as a positive electrode active material was obtained. Next, 91 parts by mass of this lithium-cobalt composite oxide, 6 parts by mass of graphite as a conductive material, and 3 parts by mass of polyvinylidene fluoride as a binder were prepared to prepare a positive electrode mixture, and then N as a solvent. -Dispersed in methyl-2-pyrrolidone to obtain a positive electrode mixture slurry. Subsequently, the positive electrode mixture slurry was uniformly applied to a positive electrode current collector 33A made of a strip-shaped aluminum foil having a thickness of 12 μm, dried, and then compression molded to form a positive electrode active material layer 33B. After that, the positive electrode lead 31 made of aluminum was attached to one end of the positive electrode current collector 33A.

  Further, an artificial graphite powder was prepared as a negative electrode active material, and 90 parts by mass of the artificial graphite powder and 10 parts by mass of polyvinylidene fluoride as a binder were prepared, and then a negative electrode mixture was prepared. A negative electrode mixture slurry was prepared by dispersing in methyl-2-pyrrolidone. Subsequently, this negative electrode mixture slurry was uniformly applied to a negative electrode current collector 34A made of a strip-shaped copper foil having a thickness of 15 μm, dried, and then compression molded to form a negative electrode active material layer 34B. Thereafter, a negative electrode lead 32 made of nickel was attached to one end of the negative electrode current collector 34A.

  After that, the positive electrode 33 and the negative electrode 34 are stacked via the separator 35 so that the positive electrode active material layer 33B and the negative electrode active material layer 34B face each other, and wound to be a precursor of the wound electrode body 30. A gyrus was formed.

  The obtained wound body is sandwiched between exterior members 40 made of a laminate film, and the outer peripheral edge except for one side is heat-sealed into a bag shape, accommodated inside the exterior member 40, and the electrolytic solution of the exterior member 40 Injected inside. Laminate films were made of nylon-aluminum-unstretched polypropylene from the outside, and their thicknesses were 30 μm, 40 μm, and 30 μm, respectively, for a total of 100 μm.

Electrolyte, in Examples 1-1 to 1-7, were mixed ethylene carbonate (EC) and as a solvent and a sultam shown in diethyl carbonate (DEC) and of 3, further 1.0mol LiPF ₆ as an electrolyte salt / Kg was dissolved. At that time, the ratio by mass ratio of ethylene carbonate and diethyl carbonate (ethylene carbonate: diethyl carbonate) was set to 2: 3. The sultam shown in Chemical formula 3, shown in the Experiment 1-1 of 4 (3) 2-Methyl - [1,2] - and isothiazolidine 1,1 Jiokisashido, in Examples 1-2 of 4 ( 4-ethyl- [1,2] -isothiazolidine 1,1-dioxaside shown in 4), and in Experimental Example 1-3, 3-methyl- [1,2] -thiazinane 1 shown in Chemical Formula 4 (22) , 1-dioxide, and in Experimental Example 1-4, 3-methyl- [1,2,3] -oxathiazolidine 2,2-dioxide shown in Chemical Formula 4 (8) was used. In Experimental Example 1-5, Chemical Formula 4 ( 9) 3-ethyl- [1,2,3] -oxathiazolidine-2,2-dioxide shown in Experimental Example 1-6, 2-methyl-2,3-dihydro shown in Chemical formula 4 (13) - and isothiazole 1,1-dioxide, shown in examples 1-7 of 4 (6) 2-vinyl-2,3-dihydro - and isothiazole 1,1-dioxide, the amount contained in the solvent was 5 wt%, respectively.

In Experimental Examples 1-8 to 1-14, 4-fluoro-1,3-dioxolan-2-one (FEC) shown in Chemical Formula 6 (1-1), which is a cyclic ester derivative having a halogen atom as a solvent, is used. ), Diethyl carbonate and sultam shown in Chemical Formula 3 were mixed, and LiPF ₆ was dissolved as an electrolyte salt to a concentration of 1.0 mol / kg. At that time, the ratio (4-fluoro-1,3-dioxolan-2-one: diethyl carbonate) based on the mass ratio of 4-fluoro-1,3-dioxolan-2-one and diethyl carbonate was 2: 3. The sultam shown in Chemical formula 3, shown in the Experiment 1-8 of 4 (3) 2-Methyl - [1,2] - and isothiazolidine 1,1 Jiokisashido, in Examples 1-9 of 4 ( 4) 2-ethyl shown in - [1,2] - and isothiazolidine 1,1 Jiokisashido, 3-methyl shown in experimental examples 1-10 in Chemical formula 4 (22) - [1,2] - thiazinane 1 , 1-dioxide, and in Experimental Example 1-11, 3-methyl- [1,2,3] -oxathiazolidine 2,2-dioxide shown in Chemical Formula 4 (8) was used. In Experimental Example 1-12, Chemical Formula 4 ( 9) 3-ethyl- [1,2,3] -oxathiazolidine-2,2-dioxide shown in Experimental Example 1-13, 2-methyl-2,3-dihydro shown in Chemical Formula 4 (13) - and isothiazole 1,1-dioxide, in examples 1-14 of 4 ( ) The indicated 2-vinyl-2,3-dihydro - and isothiazole 1,1-dioxide, the amount contained in the solvent was 5 wt%, respectively.

  After injecting the electrolytic solution, the opening of the exterior member 40 was heat-sealed and sealed in a vacuum atmosphere to produce the laminate film type secondary battery shown in FIGS. 3 and 4.

As Comparative Example 1-1 with respect to Experimental Examples 1-1 to 1-7 and 1-8 to 1-14, except that the sultam shown in Chemical Formula 3 was not used, the others were Experimental Examples 1-1 to 1-7. A secondary battery was fabricated in the same manner as described above. Further, as Comparative Example 1-2 with respect to Experimental Examples 1-8 to 1-14, except that the sultam shown in Chemical Formula 3 was not used, the others were the same as in Experimental Examples 1-8 to 1-14. A battery was produced.

Regarding the fabricated secondary batteries of Experimental Examples 1-1 to 1-14 and Comparative Examples 1-1 and 1-2, the high-temperature storage characteristics and the high-temperature cycle characteristics were examined as follows.

  First, at 23 ° C., two cycles of charge / discharge were performed, and the discharge capacity at the second cycle (discharge capacity before storage) was determined. Subsequently, the battery was charged again and stored for 10 days in a constant temperature bath at 80 ° C., and then discharged at 23 ° C. to determine the discharge capacity after storage. At that time, the charge was 0.2 C constant current and constant voltage charge up to the upper limit voltage of 4.20 V, and the discharge was 0.2 C constant current discharge to the end voltage of 2.50 V. The high-temperature storage characteristics were determined from the ratio of the discharge capacity after storage to the discharge capacity before storage, that is, (discharge capacity after storage / discharge capacity before storage) × 100 (%). The results are shown in Table 1. 0.2 C is a current value at which the theoretical capacity can be discharged in 5 hours.

  Moreover, at 23 degreeC, charging / discharging was performed 2 cycles, and the discharge capacity of the 2nd cycle (discharge capacity of the 2nd cycle in 23 degreeC) was calculated | required. Subsequently, 50 cycles of charge and discharge were performed in a 60 ° C. thermostat, and the discharge capacity at the 50th cycle (discharge capacity at the 50th cycle at 60 ° C.) was obtained. At that time, the charge was 0.2 C constant current and constant voltage charge up to the upper limit voltage of 4.20 V, and the discharge was 0.2 C constant current discharge to the end voltage of 2.50 V. The high-temperature cycle characteristic is the ratio of the discharge capacity at the 50th cycle at 60 ° C to the discharge capacity at the second cycle at 23 ° C, ie, (the discharge capacity at the 50th cycle at 60 ° C / the discharge capacity at the second cycle at 23 ° C). It calculated | required from x100 (%). The results are shown in Table 1.

As shown in Table 1, according to Experimental Examples 1-1 to 1-7 and 1-8 to 1-14 using the sultam shown in Chemical Formula 3, Comparative Examples 1-1 and 1 which did not use this were used. As compared with -2, the high-temperature storage characteristics were improved, and the high-temperature cycle characteristics were also improved. Further, according to the experimental examples 1-8～1-14 using 4-fluoro-1,3-dioxolan-2-one as a solvent, than in Experimental Example 1-1 to 1-7 was not used this, High-temperature storage characteristics or high-temperature cycle characteristics improved respectively.

  That is, if the sultam shown in Chemical Formula 3 is included in the electrolytic solution, the high temperature characteristics can be improved, and in particular, if the cyclic carbonate derivative having a halogen atom is included, the high temperature characteristics are further improved. I found out that

( Experimental examples 2-1 to 2-4)
Except that 1,3-dioxol-2-one (VC) or 4-vinyl-1,3-dioxolan-2-one (VEC), which is a cyclic carbonate of an unsaturated compound, was used as the solvent, Others were made in the same manner as in Experimental Example 1-1 or Experimental Example 1-8, and a laminate film type secondary battery was produced. At that time, the content of the cyclic carbonate of the unsaturated compound in the solvent was 2% by mass.

As Comparative Examples 2-1 and 2-2 to Experimental Examples 2-1 to 2-4, except that the sultam shown in Chemical Formula 3 was not used, the others were the same as Experimental Examples 2-1 to 2-4. A secondary battery was produced. At that time, the cyclic carbonate of the unsaturated compound was 1,3-dioxol-2-one.

For the fabricated secondary batteries of Experimental Examples 2-1 to 2-4 and Comparative Examples 2-1 and 2-2, high temperature storage characteristics and high temperature cycle characteristics were examined in the same manner as in Experimental Examples 1-1 to 1-14. . The results are shown in Table 2.

As shown in Table 2, according to Experimental Examples 2-1 and 2-2 or Experimental Examples 2-3 and 2-4 using cyclic carbonates of unsaturated compounds, Experimental Example 1 in which this was not used -1 or Experimental Example 1-8, the high temperature storage characteristics or the high temperature cycle characteristics were improved. Moreover, according to Experimental Example 2-1 or Experimental Example 2-3 using the sultam shown in Chemical Formula 3, the high-temperature storage characteristics were respectively higher than those of Comparative Example 2-1 or Comparative Example 2-2 that did not use this. Improved.

  That is, it was found that the high temperature characteristics can be further improved if the electrolytic solution further contains a cyclic carbonate of an unsaturated compound.

( Experimental examples 3-1 to 3-6)
Except that the content of 2-methyl- [1,2] -isothiazolidine 1,1-dioxaside shown in Chemical Formula 4 (3) in the solvent was changed, the other examples were Experimental Example 1-1 or Experimental Example 1 In the same manner as in Example 8, a laminate film type secondary battery was produced. At that time, the content of 2-methyl- [1,2] -isothiazolidine 1,1-dioxaside shown in Chemical Formula 4 (3) in the solvent was 15% by mass in Experimental Examples 3-1 and 3-4. In Experimental Examples 3-2 and 3-5, the content was 10% by mass, and in Experimental Examples 3-3 and 3-6, the content was 0.01% by mass.

For the secondary batteries of Experimental Examples 3-1 to 3-6 were prepared to investigate the high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14. The results are shown in Table 3.

As shown in Table 3, the high-temperature storage characteristics increased as the content of 2-methyl- [1,2] -isothiazolidine 1,1-dioxaside shown in Chemical Formula 4 (3) increased. A tendency to become almost constant was observed. The high-temperature cycle characteristics increase as the content of 2-methyl- [1,2] -isothiazolidine 1,1-dioxaside shown in Chemical Formula 4 (3) increases, and then decrease after showing a maximum value. The tendency to do was seen. Furthermore, Experimental Examples 1-1 and 3 in which the content of 2-methyl- [1,2] -isothiazolidine 1,1-dioxaside shown in Chemical Formula 4 (3) was 0.01% by mass to 10% by mass -2, 3-3, or Experimental Examples 1-8, 3-5, 3-6, 2-methyl- [1,2] -isothiazolidine 1,1-dioxaside shown in Chemical Formula 4 (3) Both the high-temperature storage characteristics and the high-temperature cycle characteristics were improved as compared with Comparative Example 1-1 or Comparative Example 1-2 in which no was used.

  That is, the content of sultam shown in Chemical Formula 3 in the solvent is preferably 0.01% by mass or more and 15% by mass or less, and more preferably 0.01% by mass or more and 10% by mass or less. I understood.

( Experimental examples 4-1 to 4-15)
In Experimental Examples 4-1 to 4-7, in addition to LiPF ₆ , lithium difluoro [oxolato-O, O ′] lithium borate shown in Chemical Formula 21, which is a light metal salt shown in Chemical Formula 12, was used as the electrolyte salt. Other than the above, secondary batteries were fabricated in the same manner as in Experimental Examples 1-1 to 1-7. At that time, the concentration of LiPF _{6 in} the electrolytic solution was 0.8 mol / kg, and the concentration of lithium difluoro [oxolato-O, O ′] lithium borate was 0.2 mol / kg.

In Experimental Examples 4-8 to 4-14, in addition to LiPF ₆ as an electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical Formula 26, which is a light metal salt shown in Chemical Formula 12, is used. Except for the above, secondary batteries were fabricated in the same manner as in Experimental Examples 1-1 to 1-7. At that time, the concentration of LiPF _{6 in} the electrolytic solution was 0.8 mol / kg, and the concentration of lithium bis [oxolato-O, O ′] lithium borate was 0.2 mol / kg.

Further, in Experimental Example 4-15, in addition to LiPF ₆ as an electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical formula 26, which is a light metal salt shown in Chemical formula 12, and a cyclic imide salt A secondary battery was fabricated in the same manner as in Experimental Example 1-1 except that 1,3-perfluoropropanedisulfonylimide lithium shown in Chemical formula 16 (2) was used. At that time, the concentration of LiPF6 in the electrolyte was 0.8 mol / kg, the concentration of lithium bis [oxolato-O, O ′] lithium borate was 0.2 mol / kg, and 1,3-perfluoropropanedisulfonylimide lithium The concentration of was 0.1 mol / kg.

As Comparative Example 4-1 with respect to Experimental Examples 4-1 to 4-15, a secondary battery was prepared in the same manner as Experimental Examples 4-1 to 4-15 except that the sultam shown in Chemical Formula 3 was not used. Produced. At that time, the solvent is a mixture of ethylene carbonate and diethyl carbonate in a mass ratio of ethylene carbonate: diethyl carbonate = 2: 3, and the type and concentration of the electrolyte salt are the same as in Experimental Examples 4-1 to 4-7. I made it.

For the secondary batteries of Experimental Examples 4-1～4-15 and Comparative Examples 4-1 were prepared to investigate the high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14. The results are shown in Table 4.

As shown in Table 4, experimental example 4 using lithium difluoro [oxolato-O, O ′] lithium borate or difluoro [oxolato-O, O ′] lithium borate in addition to LiPF ₆ as an electrolyte salt 4- According to 1-4-4 and 4-8 to 4-14, the high-temperature storage characteristics or the high-temperature cycle characteristics are improved as compared with Experimental Examples 1-1 to 1-7 that do not use them. The high-temperature storage characteristics or the high-temperature cycle characteristics were improved as compared with Comparative Example 4-1, which did not use the sultam shown in 1. Furthermore, according to Experimental Example 4-15 using 1,3-perfluoropropanedisulfonylimide lithium in addition to LiPF ₆ and difluoro [oxolato-O, O ′] lithium borate, 1,3-perfluoro High-temperature storage characteristics or high-temperature cycle characteristics were improved as compared with Experimental Example 4-1, which did not use propanedisulfonylimide lithium.

That is, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , lithium salt shown in Chemical formula 8, lithium salt shown in Chemical formula 9, cyclic imide salt shown in Chemical formula 10, cyclic imide salt shown in Chemical formula 11 It was found that the use of at least one member selected from the group consisting of light metal salts shown in Chemical formula 12 and Chemical formula 12 can further improve the high temperature characteristics.

( Experimental examples 5-1 to 5-14)
A so-called lithium metal secondary battery in which the capacity of the negative electrode is expressed by a capacity component due to precipitation and dissolution of lithium was produced. At that time, except that lithium metal was used for the negative electrode active material and the negative electrode current collector 34A made of a strip-shaped copper foil having a thickness of 15 μm was pressure-bonded with 30 μm thick lithium metal to form the negative electrode active material layer 34B. Laminated film type secondary batteries were produced in the same manner as in Experimental Examples 1-1 to 1-14.

As Comparative Examples 5-1 and 5-2 to Experimental Examples 5-1 to 5-14, except that the sultam shown in Chemical Formula 3 was not used, that is, the same electrolysis as Comparative Examples 1-1 and 1-2 A secondary battery was fabricated in the same manner as in Experimental Examples 5-1 to 5-14, except that the liquid was used.

For the secondary batteries of Experimental Examples 5-1～5-14 and Comparative Examples 5-1 and 5-2 were produced to investigate the high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14 . The results are shown in Table 5.

As shown in Table 5, the same results as in Experimental Examples 1-1 to 1-14 were obtained. That is, even when lithium metal is used as the negative electrode active material, the high temperature characteristics can be improved by including the sultam shown in Chemical Formula 3 in the electrolyte, and in particular, a cyclic carbonate having a halogen atom. It was found that high temperature characteristics can be further improved by including a derivative.

( Experimental examples 6-1 to 6-4)
Specific experimental examples except that 1,3-dioxol-2-one or 4-vinyl-1,3-dioxolan-2-one, which is a cyclic carbonate of an unsaturated compound, was used as the solvent. A laminated film type secondary battery was fabricated in the same manner as in Experimental Example 5-1 or Experimental Example 5-8 except that the same electrolytic solution as in 2-1 to 2-4 was used.

As Comparative Examples 6-1 and 6-2 for Experimental Examples 6-1 to 6-4, except that the sultam shown in Chemical Formula 3 was not used, specifically, Comparative Examples 2-1 and 2-2 A secondary battery was fabricated in the same manner as in Experimental Examples 6-1 to 6-4, except that the same electrolytic solution was used.

For the secondary batteries of Experimental Examples 6-1 to 6-4 and Comparative Examples 6-1 and 6-2 were produced to investigate the high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14 . The results are shown in Table 6.

As shown in Table 6, the same results as in Experimental Examples 2-1 to 2-4 were obtained. That is, it was found that even when lithium metal is used as the negative electrode active material, the high temperature characteristics can be further improved if the electrolyte further contains a cyclic carbonate ester of an unsaturated compound.

( Experimental examples 7-1 to 7-6)
Specifically, except for changing the content of 2-methyl- [1,2] -isothiazolidine 1,1-dioxaside shown in Chemical Formula 4 (3) in the solvent, Experimental Examples 3-1 to 3 A laminated film type secondary battery was produced in the same manner as in Experimental Example 5-1 or Experimental Example 5-8, except that the same electrolytic solution as in -6 was used.

For the secondary batteries of Experimental Examples 7-1 to 7-6 were prepared to investigate the high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14. The results are shown in Table 7.

As shown in Table 7, the same results as in Experimental Examples 3-1 to 3-6 were obtained. That is, even when lithium is used as the negative electrode active material, the content of sultam shown in Chemical Formula 3 in the solvent is preferably 0.01% by mass or more and 15% by mass or less, and preferably 0.01% by mass or more and 10% by mass. It was found that the following would be more preferable.

( Experimental examples 8-1 to 8-15)
In Experimental Examples 8-1 to 8-7, in addition to LiPF ₆ , lithium difluoro [oxolato-O, O ′] lithium borate shown in Chemical Formula 21, which is a light metal salt shown in Chemical Formula 12, was used as the electrolyte salt. Specifically, a secondary battery was fabricated in the same manner as in Experimental Examples 5-1 to 5-7, except that the same electrolytic solution as in Experimental Examples 4-1 to 4-7 was used. .

Further, in Experimental Examples 8-8 to 8-14, in addition to LiPF ₆ as an electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical formula 26, which is a light metal salt shown in Chemical formula 12, is used. Specifically, except that the same electrolytic solution as in Experimental Examples 4-8 to 4-14 was used, the secondary battery was manufactured in the same manner as in Experimental Examples 5-1 to 5-7. Produced.

Further, in Experimental Example 8-15, in addition to LiPF ₆ as an electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical formula 26, which is a light metal salt shown in Chemical formula 12, and a cyclic imide salt Except for using 1,3-perfluoropropanedisulfonylimide lithium shown in Chemical Formula 16 (2), specifically, using the same electrolytic solution as in Experimental Example 4-15, A secondary battery was fabricated in the same manner as in Experimental Example 5-1.

Specifically, as Comparative Example 8-1 for Experimental Examples 8-1 to 8-15, except that the sultam shown in Chemical Formula 3 was not used, specifically, the same electrolytic solution as Comparative Example 4-1 was used. Other than the above, secondary batteries were fabricated in the same manner as in Experimental Examples 5-1 to 5-15.

For the secondary batteries of Experimental Examples 8-1～8-15 and Comparative Examples 8-1 were prepared to investigate the high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14. The results are shown in Table 8.

As shown in Table 8, the same results as in Experimental Examples 4-1 to 4-15 were obtained. That is, even when lithium metal is used as the negative electrode active material, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , the lithium salt shown in Chemical formula 8, the lithium salt shown in Chemical formula 9, and the cyclic shown in Chemical formula 10 It was found that the high temperature characteristics can be further improved by using at least one member selected from the group consisting of the imide salt of the above, the cyclic imide salt shown in Chemical Formula 11 and the light metal salt shown in Chemical Formula 12. .

( Experimental examples 9-1 to 9-14)
A so-called lithium ion secondary battery in which the capacity of the negative electrode is represented by a capacity component due to insertion and extraction of lithium was produced. At that time, except that silicon was used as the negative electrode active material and the negative electrode active material layer 34B made of silicon was formed on the negative electrode current collector 34A made of copper foil having a thickness of 15 μm by the electron beam evaporation method, the others were experimental. In the same manner as in Examples 1-1 to 1-14, a laminate film type secondary battery was produced.

As Comparative Examples 9-1 and 9-2 for Experimental Examples 9-1 to 9-14, except that the sultam shown in Chemical Formula 3 was not used, that is, the same electrolysis as Comparative Examples 1-1 and 1-2 A secondary battery was fabricated in the same manner as in Experimental Examples 9-1 to 9-14, except that the liquid was used.

For the secondary batteries of Experimental Examples 9-1～9-14 and Comparative Examples 9-1 and 9-2 were produced to investigate the high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14 . The results are shown in Table 9.

As shown in Table 9, the same results as in Experimental Examples 1-1 to 1-14 were obtained. That is, even when other negative electrode active materials are used, if the sultam shown in Chemical Formula 3 is included in the electrolytic solution, the high temperature characteristics can be improved, and in particular, cyclic carbonate derivatives having halogen atoms. It has been found that the high temperature characteristics can be further improved by including.

( Experimental examples 10-1 to 10-4)
Specific experimental examples except that 1,3-dioxol-2-one or 4-vinyl-1,3-dioxolan-2-one, which is a cyclic carbonate of an unsaturated compound, was used as the solvent. A laminated film type secondary battery was fabricated in the same manner as in Experimental Example 9-1 or Experimental Example 9-8 except that the same electrolytic solution as in 2-1 to 2-4 was used.

As Comparative Examples 10-1 and 10-2 for Experimental Examples 10-1 to 10-4, except that the sultam shown in Chemical Formula 3 was not used, specifically, Comparative Examples 2-1 and 2-2 A secondary battery was fabricated in the same manner as in Experimental Examples 9-1 to 9-4, except that the same electrolytic solution was used.

For the fabricated secondary batteries of Experimental Examples 10-1 to 10-4 and Comparative Examples 10-1 and 10-2, the high temperature storage characteristics and the high temperature cycle characteristics were examined in the same manner as in Experimental Examples 1-1 to 1-14. . The results are shown in Table 10.

As shown in Table 10, the same results as in Experimental Examples 2-1 to 2-4 were obtained. That is, even when other negative electrode active materials were used, it was found that the high temperature characteristics could be further improved if the electrolyte solution further contained a cyclic carbonate ester of an unsaturated compound.

( Experimental examples 11-1 to 11-6)
Specifically, except for changing the content of 2-methyl- [1,2] -isothiazolidine 1,1-dioxaside shown in Chemical Formula 4 (3) in the solvent, Experimental Examples 3-1 to 3 A laminated film type secondary battery was produced in the same manner as in Experimental Example 9-1 or Experimental Example 9-8, except that the same electrolytic solution as in −6 was used.

For the secondary batteries of Examples 11-1 to 11-6 were prepared to investigate the high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14. The results are shown in Table 11.

As shown in Table 11, the same results as in Experimental Examples 3-1 to 3-6 were obtained. That is, even when other negative electrode active materials are used, the content of sultam shown in Chemical formula 3 in the solvent is preferably 0.01% by mass or more and 15% by mass or less, preferably 0.01% by mass or more and 10% by mass. It was found that the following would be more preferable.

( Experimental examples 12-1 to 12-15)
In Experimental Examples 12-1 to 12-7, in addition to LiPF ₆ , lithium difluoro [oxolato-O, O ′] lithium borate shown in Chemical Formula 21 as a light metal salt shown in Chemical Formula 12 was used as an electrolyte salt. Specifically, a secondary battery was fabricated in the same manner as in Experimental Examples 9-1 to 9-7 except that the same electrolytic solution as in Experimental Examples 4-1 to 4-7 was used. .

In Experimental Examples 12-8 to 12-14, in addition to LiPF ₆ as the electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical Formula 26, which is a light metal salt shown in Chemical Formula 12, is used. Specifically, except that the same electrolytic solution as in Experimental Examples 4-8 to 4-14 was used, other than that, the secondary battery was manufactured in the same manner as in Experimental Examples 9-1 to 9-7. Produced.

Further, in Experimental Example 12-15, in addition to LiPF ₆ as an electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical formula 26, which is a light metal salt shown in Chemical formula 12, and a cyclic imide salt Except for using 1,3-perfluoropropanedisulfonylimide lithium shown in Chemical Formula 16 (2), specifically, using the same electrolytic solution as in Experimental Example 4-15, A secondary battery was fabricated in the same manner as in Experimental Example 9-1.

Specifically, as Comparative Example 12-1 for Experimental Examples 12-1 to 12-15, except that the sultam shown in Chemical Formula 3 was not used, specifically, the same electrolytic solution as Comparative Example 4-1 was used. Other than the above, secondary batteries were fabricated in the same manner as in Experimental Examples 9-1 to 9-15.

For the secondary batteries of Experimental Examples 12-1～12-15 and Comparative Example 12-1 were produced, were examined high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14. The results are shown in Table 12.

As shown in Table 12, the same results as in Experimental Examples 4-1 to 4-15 were obtained. That is, even when other negative electrode active materials are used, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , lithium salt shown in Chemical formula 8, lithium salt shown in Chemical formula 9 and cyclic formula shown in Chemical formula 10 It was found that the use of at least one of the group consisting of an imide salt, a cyclic imide salt shown in Chemical Formula 11 and a light metal salt shown in Chemical Formula 12 can further improve the high temperature characteristics.

( Experimental examples 13-1 to 13-6)
A so-called lithium ion secondary battery in which the capacity of the negative electrode is represented by a capacity component due to insertion and extraction of lithium was produced. At that time, CoSnC-containing material powder is used for the negative electrode active material, 80 parts by mass of this CoSnC-containing material powder, 11 parts by mass of graphite which is a negative electrode active material and also a conductive material, 1 part by mass of acetylene black, and as a binder After 8 parts by mass of polyvinylidene fluoride is dispersed in N-methyl-2-pyrrolidone as a solvent, it is uniformly applied to a negative electrode current collector 34A made of a strip-shaped copper foil having a thickness of 10 μm and dried at a constant pressure. A secondary battery was fabricated in the same manner as in Experimental Examples 1-1, 1-3, 1-6, 1-8, 1-10, 1-13 except that the negative electrode active material layer 34B was formed by molding. Produced.

  At that time, the CoSnC-containing material powder was synthesized by mixing a tin / cobalt / indium / titanium alloy powder and a carbon powder and utilizing a mechanochemical reaction. When the composition of the obtained CoSnC-containing material was analyzed, the content of tin was 48.0% by mass, the content of cobalt was 23.0% by mass, the content of carbon was 20.0% by mass, The ratio Co / (Sn + Co) of cobalt to the total with cobalt was 32% by mass. The carbon content was measured by a carbon / sulfur analyzer, and the tin and cobalt contents were measured by ICP (Inductively Coupled Plasma) emission analysis. Further, when X-ray diffraction was performed on the obtained CoSnC-containing material, a diffraction peak having a wide half-width with a diffraction angle 2θ of 1.0 ° or more was observed between diffraction angles 2θ = 20 ° to 50 °. It was. Further, when XPS was performed on the CoSnC-containing material, a peak P1 was obtained as shown in FIG. When the peak P1 was analyzed, a peak P2 of surface contamination carbon and a peak P3 of C1s in the CoSnC-containing material on the lower energy side than the peak P2 were obtained. This peak P3 was obtained in a region lower than 284.5 eV. That is, it was confirmed that carbon in the CoSnC-containing material was bonded to other elements.

As Comparative Examples 13-1 and 13-2 for Experimental Examples 13-1 to 13-6, except that the sultam shown in Chemical Formula 3 was not used, that is, the same electrolysis as Comparative Examples 1-1 and 1-2 A secondary battery was fabricated in the same manner as in Experimental Examples 13-1 to 13-6, except that the liquid was used.

For the secondary batteries of Experimental Examples 13-1～13-6 and Comparative Examples 13-1 and 13-2 were produced, it was examined high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14 . The results are shown in Table 13.

As shown in Table 13, the same results as in Experimental Examples 1-1 to 1-14 were obtained. That is, even when other negative electrode active materials are used, if the sultam shown in Chemical Formula 3 is included in the electrolytic solution, the high temperature characteristics can be improved, and in particular, cyclic carbonate derivatives having halogen atoms. It has been found that the high temperature characteristics can be further improved by including.

( Experimental examples 14-1 to 14-4)
Specific experimental examples except that 1,3-dioxol-2-one or 4-vinyl-1,3-dioxolan-2-one, which is a cyclic carbonate of an unsaturated compound, was used as the solvent. A laminated film type secondary battery was fabricated in the same manner as in Experimental Example 13-1 or Experimental Example 13-4 except that the same electrolytic solution as in 2-1 to 2-4 was used.

As Comparative Examples 14-1 and 14-2 for Experimental Examples 14-1 to 14-4, except that the sultam shown in Chemical Formula 3 was not used, specifically, Comparative Examples 2-1 and 2-2 A secondary battery was fabricated in the same manner as in Experimental Examples 14-1 to 14-4, except that the same electrolytic solution was used.

For the secondary batteries of Examples 14-1 to 14-4 and Comparative Examples 14-1 and 14-2 were produced, it was examined high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14 . The results are shown in Table 14.

As shown in Table 14, the same results as in Experimental Examples 2-1 to 2-4 were obtained. That is, even when other negative electrode active materials were used, it was found that the high temperature characteristics could be further improved if the electrolyte solution further contained a cyclic carbonate ester of an unsaturated compound.

( Experimental Examples 15-1 to 15-6)
Specifically, except for changing the content of 2-methyl- [1,2] -isothiazolidine 1,1-dioxaside shown in Chemical Formula 4 (3) in the solvent, Experimental Examples 3-1 to 3 A laminated film type secondary battery was produced in the same manner as in Experimental Example 13-1 or Experimental Example 13-4, except that the same electrolytic solution as in −6 was used.

For the fabricated secondary batteries of Experimental Examples 13-1 to 13-6, high temperature storage characteristics and high temperature cycle characteristics were examined in the same manner as in Experimental Examples 1-1 to 1-14. The results are shown in Table 15.

As shown in Table 15, the same results as in Experimental Examples 3-1 to 3-6 were obtained. That is, even when other negative electrode active materials are used, the content of sultam shown in Chemical formula 3 in the solvent is preferably 0.01% by mass or more and 15% by mass or less, preferably 0.01% by mass or more and 10% by mass. It was found that the following would be more preferable.

( Experimental Examples 16-1 to 16-7)
In Experimental Examples 16-1 to 16-3, in addition to LiPF ₆ , lithium difluoro [oxolato-O, O ′] lithium borate shown in Chemical Formula 21, which is a light metal salt shown in Chemical Formula 12, was used as the electrolyte salt. Specifically, except that the same electrolytic solution as in Experimental Examples 4-1, 4-3, and 4-6 was used, the others were the same as in Experimental Examples 13-1 to 13-3. A battery was produced.

In Experimental Examples 16-4 to 16-6, in addition to LiPF ₆ as an electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical Formula 26, which is a light metal salt shown in Chemical Formula 12, is used. Specifically, except for using the same electrolytic solution as in Experimental Examples 4-8, 4-10, and 4-13, the rest was the same as in Experimental Examples 13-1 to 13-3. A secondary battery was produced.

Further, in Experimental Example 16-7, in addition to LiPF ₆ as the electrolyte salt, bis [oxolato-O, O ′] lithium borate shown in Chemical formula 26, which is a light metal salt shown in Chemical formula 12, and cyclic imide salt Except for using 1,3-perfluoropropanedisulfonylimide lithium shown in Chemical Formula 16 (2), specifically, using the same electrolytic solution as in Experimental Example 4-15, Otherwise, a secondary battery was fabricated in the same manner as in Experimental Example 13-1.

Specifically, as Comparative Example 16-1 for Experimental Examples 16-1 to 16-7, the same electrolytic solution as Comparative Example 4-1 was used, except that the sultam shown in Chemical Formula 3 was not used. Other than the above, secondary batteries were fabricated in the same manner as in Experimental Examples 16-1 to 16-7.

For the secondary batteries of Experimental Examples 16-1～16-7 and Comparative Example 16-1 were produced, were examined high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14. The results are shown in Table 16.

As shown in Table 16, the same results as in Experimental Examples 4-1 to 4-15 were obtained. That is, even when other negative electrode active materials are used, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , lithium salt shown in Chemical formula 8, lithium salt shown in Chemical formula 9 and cyclic formula shown in Chemical formula 10 It was found that the use of at least one of the group consisting of an imide salt, a cyclic imide salt shown in Chemical Formula 11 and a light metal salt shown in Chemical Formula 12 can further improve the high temperature characteristics.

( Experimental Examples 17-1 and 17-2)
The cylindrical secondary battery shown in FIGS. 1 and 2 was produced. At that time, a so-called lithium ion secondary battery in which the capacity of the negative electrode was expressed by a capacity component due to insertion and extraction of lithium was produced. First, a positive electrode 21 and a negative electrode 22 were prepared in the same manner as in Experimental Examples 1-1 to 1-14, and attached to an aluminum positive electrode lead 25 and a nickel negative electrode lead 26, respectively.

  After preparing the positive electrode 21 and the negative electrode 22, a separator 23 made of a microporous polypropylene film having a thickness of 25 μm is prepared, and the negative electrode 22, the separator 23, the positive electrode 21, and the separator 23 are stacked in this order to form a spiral structure. The wound electrode body 20 was produced by winding a number of times.

After producing the wound electrode body 20, the wound electrode body 20 is sandwiched between the pair of insulating plates 12 and 13, the negative electrode lead 26 is welded to the battery can 11, and the positive electrode lead 25 is welded to the safety valve mechanism 15. The wound electrode body 20 was housed inside a nickel-plated iron battery can 11. After that, an electrolytic solution was injected into the battery can 11 by a reduced pressure method. As the electrolytic solution, the same one as in Experimental Examples 1-1 and 1-8 was used.

  After injecting the electrolyte into the battery can 11, the battery lid 14 was caulked to the battery can 11 via the gasket 17 to obtain a cylindrical secondary battery.

As Comparative Examples 17-1 and 17-2 with respect to Experimental Examples 17-1 and 17-2, except that the sultam shown in Chemical Formula 3 was not used, specifically, Comparative Examples 1-1 and 1-2 and A secondary battery was fabricated in the same manner as in Experimental Examples 17-1 and 17-2 except that the same electrolytic solution was used.

Regarding the fabricated secondary batteries of Experimental Examples 17-1 and 17-2 and Comparative Examples 17-1 and 17-2, the high temperature storage characteristics and the high temperature cycle characteristics were examined in the same manner as in Experimental Examples 1-1 to 1-14. . The results are shown in Table 17.

As shown in Table 17, the same results as in Experimental Examples 1-1 to 1-14 were obtained. That is, even in the case of a secondary battery having another shape, if the sultam shown in Chemical Formula 3 is included in the electrolyte, the high temperature characteristics can be improved, and in particular, the cyclic carbonate having a halogen atom. It was found that high temperature characteristics can be further improved by including a derivative.

( Experimental examples 18-1 to 18-3)
In Experimental Example 18-1, in addition to LiPF ₆ as an electrolyte salt, the difluoro [oxolato-O, O ′] lithium borate shown in Chemical formula 21, which is a light metal salt shown in Chemical formula 12, was used. Specifically, a cylindrical secondary battery was fabricated in the same manner as in Experimental Example 17-1, except that the same electrolytic solution as in Experimental Example 4-1 was used.

Further, in Experimental Example 18-2, in addition to LiPF ₆ as the electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical formula 26, which is a light metal salt shown in Chemical formula 12, was used. Specifically, a cylindrical secondary battery was fabricated in the same manner as in Experimental Example 17-1, except that the same electrolytic solution as in Experimental Example 4-8 was used.

Further, in Experimental Example 18-3, in addition to LiPF ₆ as an electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical formula 26, which is a light metal salt shown in Chemical formula 12, and a cyclic imide salt Except for using 1,3-perfluoropropanedisulfonylimide lithium shown in Chemical Formula 16 (2), specifically, using the same electrolytic solution as in Experimental Example 4-15, Otherwise, a secondary battery was fabricated in the same manner as in Experimental Example 17-1.

Specifically, as Comparative Example 18-1 for Experimental Examples 18-1 to 18-3, the same electrolytic solution as Comparative Example 4-1 was used, except that the sultam shown in Chemical Formula 3 was not used. Other than the above, secondary batteries were fabricated in the same manner as in Experimental Examples 18-1 to 18-3.

For the secondary batteries of Examples 18-1 to 18-3 and Comparative Example 18-1 were produced, it was examined high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14. The results are shown in Table 18.

As shown in Table 18, the same results as in Experimental Examples 4-1 to 4-15 were obtained. That is, in the case of a secondary battery having another shape, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , a lithium salt shown in Chemical Formula 8, a lithium salt shown in Chemical Formula 9 and a ring shown in Chemical Formula 10 It was found that the high temperature characteristics can be further improved by using at least one member selected from the group consisting of the imide salt of the above, the cyclic imide salt shown in Chemical Formula 11 and the light metal salt shown in Chemical Formula 12. .

( Experimental Examples 19-1 and 19-2)
A so-called lithium metal secondary battery in which the capacity of the negative electrode is expressed by a capacity component due to precipitation and dissolution of lithium was produced. At that time, except that lithium metal was used for the negative electrode active material and the negative electrode current collector 22A made of a strip-shaped copper foil having a thickness of 15 μm was pressure-bonded with 30 μm thick lithium metal to form the negative electrode active material layer 22B. Cylindrical secondary batteries were produced in the same manner as in Experimental Examples 17-1 and 17-2. At that time, the electrolytic solution was the same as in Experimental Examples 1-1 and 1-8.

As Comparative Examples 19-1 and 19-2 with respect to Experimental Examples 19-1 and 19-2, except that the sultam shown in Chemical Formula 3 was not used, specifically, Comparative Examples 1-1 and 1-2 and A secondary battery was fabricated in the same manner as in Experimental Examples 19-1 and 19-2 except that the same electrolytic solution was used.

Regarding the fabricated secondary batteries of Experimental Examples 19-1 and 19-2 and Comparative Examples 19-1 and 19-2, the high-temperature storage characteristics and the high-temperature cycle characteristics were examined in the same manner as in Experimental Examples 1-1 to 1-14. . The results are shown in Table 19.

As shown in Table 19, the same results as in Experimental Examples 1-1 to 1-14 were obtained. That is, even in the case of a secondary battery having another shape, if the sultam shown in Chemical Formula 3 is included in the electrolyte, the high temperature characteristics can be improved, and in particular, the cyclic carbonate having a halogen atom. It was found that high temperature characteristics can be further improved by including a derivative.

( Experimental examples 20-1 to 20-3)
In Experimental Example 20-1, in addition to LiPF ₆ as an electrolyte salt, a dimetal [oxolato-O, O ′] lithium borate shown in Chemical Formula 21, which is a light metal salt shown in Chemical Formula 12, was used. Specifically, a cylindrical secondary battery was produced in the same manner as in Experimental Example 19-1, except that the same electrolytic solution as in Experimental Example 4-1 was used.

Further, in Experimental Example 20-2, in addition to LiPF ₆ as the electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical Formula 26, which is a light metal salt shown in Chemical Formula 12, was used. Specifically, a cylindrical secondary battery was fabricated in the same manner as in Experimental Example 19-1, except that the same electrolytic solution as in Experimental Example 4-8 was used.

Further, in Experimental Example 20-3, in addition to LiPF ₆ as an electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical formula 26, which is a light metal salt shown in Chemical formula 12, and a cyclic imide salt Except for using 1,3-perfluoropropanedisulfonylimide lithium shown in Chemical Formula 16 (2), specifically, using the same electrolytic solution as in Experimental Example 4-15, Otherwise, a secondary battery was fabricated in the same manner as in Experimental Example 19-1.

Specifically, as Comparative Example 20-1 for Experimental Examples 20-1 to 20-3, the same electrolytic solution as Comparative Example 4-1 was used, except that the sultam shown in Chemical Formula 3 was not used. Other than the above, secondary batteries were fabricated in the same manner as in Experimental Examples 20-1 to 20-3.

For the secondary batteries of Examples 20-1 to 20-3 and Comparative Example 20-1 were produced, it was examined high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14. The results are shown in Table 20.

As shown in Table 20, the same results as in Experimental Examples 4-1 to 4-15 were obtained. That is, in the case of a secondary battery having another shape, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , a lithium salt shown in Chemical Formula 8, a lithium salt shown in Chemical Formula 9 and a ring shown in Chemical Formula 10 It was found that the high temperature characteristics can be further improved by using at least one member selected from the group consisting of the imide salt of the above, the cyclic imide salt shown in Chemical Formula 11 and the light metal salt shown in Chemical Formula 12. .

( Experimental examples 21-1, 21-2)
A so-called lithium ion secondary battery in which the capacity of the negative electrode is represented by a capacity component due to insertion and extraction of lithium was produced. At that time, except that silicon was used as the negative electrode active material and the negative electrode 22 produced in the same manner as in Experimental Examples 9-1 to 9-14 was used, the rest was the same as in Experimental Examples 17-1 and 17-2. A type secondary battery was produced. At that time, the electrolytic solution was the same as in Experimental Examples 1-1 and 1-8.

Specifically, as Comparative Examples 21-1 and 21-2 with respect to Experimental Examples 21-1 and 21-2, except that the sultam shown in Chemical Formula 3 was not used, Comparative Examples 1-1 and 1-2 and A secondary battery was fabricated in the same manner as in Experimental Examples 21-1 and 21-2 except that the same electrolytic solution was used.

For the fabricated secondary batteries of Experimental Examples 21-1, 21-2 and Comparative Examples 21-1, 21-2, the high temperature storage characteristics and the high temperature cycle characteristics were examined in the same manner as in Experimental Examples 1-1 to 1-14. . The results are shown in Table 21.

As shown in Table 21, the same results as in Experimental Examples 1-1 to 1-14 were obtained. That is, even in the case of a secondary battery having another shape, if the sultam shown in Chemical Formula 3 is included in the electrolyte, the high temperature characteristics can be improved, and in particular, the cyclic carbonate having a halogen atom. It was found that high temperature characteristics can be further improved by including a derivative.

( Experimental examples 22-1 to 22-3)
In Experimental Example 22-1, in addition to LiPF ₆ as the electrolyte salt, the difluoro [oxolato-O, O ′] lithium borate shown in Chemical Formula 21, which is a light metal salt shown in Chemical Formula 12, was used. Specifically, a cylindrical secondary battery was fabricated in the same manner as in Experimental Example 21-1, except that the same electrolytic solution as in Experimental Example 4-1 was used.

Further, in Experimental Example 22-2, in addition to LiPF ₆ as an electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical Formula 26, which is a light metal salt shown in Chemical Formula 12, was used. Specifically, a cylindrical secondary battery was fabricated in the same manner as in Experimental Example 21-1, except that the same electrolytic solution as in Experimental Example 4-8 was used.

Furthermore, in Experimental Example 22-3, in addition to LiPF ₆ as an electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical formula 26, which is a light metal salt shown in Chemical formula 12, and a cyclic imide salt Except for using 1,3-perfluoropropanedisulfonylimide lithium shown in Chemical Formula 16 (2), specifically, using the same electrolytic solution as in Experimental Example 4-15, A secondary battery was fabricated in the same manner as in Experimental Example 21-1.

Specifically, as Comparative Example 22-1 for Experimental Examples 22-1 to 22-3, the same electrolytic solution as Comparative Example 4-1 was used, except that the sultam shown in Chemical Formula 3 was not used. Other than the above, secondary batteries were fabricated in the same manner as in Experimental Examples 22-1 to 22-3.

Regarding the fabricated secondary batteries of Experimental Examples 22-1 to 22-3 and Comparative Example 22-1, the high temperature storage characteristics and the high temperature cycle characteristics were examined in the same manner as in Experimental Examples 1-1 to 1-14. The results are shown in Table 22.

As shown in Table 22, the same results as in Experimental Examples 4-1 to 4-15 were obtained. That is, in the case of a secondary battery having another shape, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , a lithium salt shown in Chemical Formula 8, a lithium salt shown in Chemical Formula 9 and a ring shown in Chemical Formula 10 It was found that the high temperature characteristics can be further improved by using at least one member selected from the group consisting of the imide salt of the above, the cyclic imide salt shown in Chemical Formula 11 and the light metal salt shown in Chemical Formula 12. .

( Experimental Examples 23-1, 23-2)
A so-called lithium ion secondary battery in which the capacity of the negative electrode is represented by a capacity component due to insertion and extraction of lithium was produced. At that time, except that CoSnC-containing material powder was used as the negative electrode active material, and the negative electrode 22 produced in the same manner as in Experimental Examples 13-1 to 13-6 was used, the others were the same as in Experimental Examples 17-1 and 17-2. Thus, a cylindrical secondary battery was produced. At that time, the electrolytic solution was the same as in Experimental Examples 1-1 and 1-8.

As Comparative Examples 23-1 and 23-2 with respect to Experimental Examples 23-1 and 23-2, except that the sultam shown in Chemical Formula 3 was not used, specifically, Comparative Examples 1-1 and 1-2 and A secondary battery was fabricated in the same manner as in Experimental Examples 23-1 and 23-2 except that the same electrolytic solution was used.

Regarding the fabricated secondary batteries of Experimental Examples 23-1 and 23-2 and Comparative Examples 23-1 and 23-2, the high-temperature storage characteristics and the high-temperature cycle characteristics were examined in the same manner as in Experimental Examples 1-1 to 1-14. . The results are shown in Table 23.

As shown in Table 23, the same results as in Experimental Examples 1-1 to 1-14 were obtained. That is, even in the case of a secondary battery having another shape, if the sultam shown in Chemical Formula 3 is included in the electrolyte, the high temperature characteristics can be improved, and in particular, the cyclic carbonate having a halogen atom. It was found that high temperature characteristics can be further improved by including a derivative.

( Experimental examples 24-1 to 24-3)
In Experimental Example 24-1, in addition to LiPF ₆ as the electrolyte salt, the difluoro [oxolato-O, O ′] lithium borate shown in Chemical Formula 21, which is a light metal salt shown in Chemical Formula 12, was used. Specifically, a cylindrical secondary battery was fabricated in the same manner as in Experimental Example 23-1, except that the same electrolytic solution as in Experimental Example 4-1 was used.

In Experimental Example 24-2, in addition to LiPF ₆ as the electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical Formula 26, which is a light metal salt shown in Chemical Formula 12, was used. Specifically, a cylindrical secondary battery was fabricated in the same manner as in Experimental Example 23-1, except that the same electrolytic solution as in Experimental Example 4-8 was used.

Further, in Experimental Example 24-3, in addition to LiPF ₆ as an electrolyte salt, lithium bis [oxolato-O, O ′] lithium borate shown in Chemical formula 26, which is a light metal salt shown in Chemical formula 12, and a cyclic imide salt Except for using 1,3-perfluoropropanedisulfonylimide lithium shown in Chemical Formula 16 (2), specifically, using the same electrolytic solution as in Experimental Example 4-15, Otherwise, a secondary battery was fabricated in the same manner as in Experimental Example 23-1.

Specifically, as Comparative Example 24-1 with respect to Experimental Examples 24-1 to 24-3, the same electrolytic solution as Comparative Example 4-1 was used, except that the sultam shown in Chemical Formula 3 was not used. Other than the above, secondary batteries were fabricated in the same manner as in Experimental Examples 24-1 to 24-3.

For the secondary batteries of Examples 24-1 to 24-3 and Comparative Example 24-1 were produced, it was examined high-temperature storage characteristics and high-temperature cycle characteristics in the same manner as in Experimental Example 1-1 to 1-14. The results are shown in Table 24.

As shown in Table 24, the same results as in Experimental Examples 4-1 to 4-15 were obtained. That is, in the case of a secondary battery having another shape, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , a lithium salt shown in Chemical Formula 8, a lithium salt shown in Chemical Formula 9 and a ring shown in Chemical Formula 10 It was found that the high temperature characteristics can be further improved by using at least one member selected from the group consisting of the imide salt of the above, the cyclic imide salt shown in Chemical Formula 11 and the light metal salt shown in Chemical Formula 12. .

  Although the present invention has been described with reference to the embodiments and examples, the present invention is not limited to the embodiments and examples, and various modifications can be made. For example, in the above-described embodiments and examples, the case where the electrolyte solution or the gel electrolyte in which the polymer solution is held in the polymer compound is used as the electrolyte has been described, but other electrolytes may be used. Other electrolytes include, for example, a mixture of an ion conductive inorganic compound such as ion conductive ceramics, ion conductive glass or ionic crystal and an electrolytic solution, or a mixture of another inorganic compound and an electrolytic solution. Or a mixture of these inorganic compounds and a gel electrolyte.

  In the above embodiment and examples, a battery using lithium as an electrode reactant has been described. However, other alkali metals such as sodium (Na) or potassium (K), or alkalis such as magnesium or calcium (Ca) are used. The present invention can also be applied to the case of using an earth metal or another light metal such as aluminum. In that case, a positive electrode active material etc. can be suitably selected according to an electrode reaction material.

  Furthermore, in the above embodiments and examples, the capacity of the negative electrode is expressed by a capacity component due to insertion and extraction of lithium, or a so-called lithium ion secondary battery, or lithium metal is used for the negative electrode active material, and the capacity of the negative electrode is The so-called lithium metal secondary battery represented by the capacity component due to the precipitation and dissolution of lithium has been described, but the present invention provides a charge capacity of the negative electrode material capable of inserting and extracting lithium more than the charge capacity of the positive electrode. The same applies to a secondary battery in which the capacity of the negative electrode includes a capacity component due to insertion and extraction of lithium and a capacity component due to precipitation and dissolution of lithium, and is expressed by the sum thereof, by reducing the capacity. be able to.

In addition, in the above embodiments or examples, a cylindrical or laminated film type secondary battery has been specifically described, but the present invention has other shapes such as a square shape, a button shape, or a coin shape. The present invention can be similarly applied to secondary batteries having other structures or secondary batteries having other structures such as a stacked structure .

It is sectional drawing showing the structure of the secondary battery which concerns on the 1st Embodiment of this invention. It is sectional drawing which expands and represents a part of winding electrode body in the secondary battery shown in FIG. It is a disassembled perspective view showing the structure of the secondary battery which concerns on the 2nd Embodiment of this invention. It is sectional drawing showing the structure along the II line of the winding electrode body shown in FIG. 1 shows an example of a peak obtained by X-ray photoelectron spectroscopy relating to a CoSnC-containing material produced in an example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Battery can, 12, 13 ... Insulation board, 14 ... Battery cover, 15 ... Safety valve mechanism, 15A ... Disc board, 16 ... Heat sensitive resistance element, 17 ... Gasket, 20, 30 ... Winding electrode body, 21, 33 ... Positive electrode, 21A, 33A ... Positive electrode current collector, 21B, 33B ... Positive electrode active material layer, 22, 34 ... Negative electrode, 22A, 34A ... Negative electrode current collector, 22B, 34B ... Negative electrode active material layer, 23, 35 ... Separator , 24 ... Center pin, 25, 31 ... Positive electrode lead, 26, 32 ... Negative electrode lead, 36 ... Electrolyte layer, 37 ... Protective tape, 40 ... Exterior member, 41 ... Adhesion film.

Claims (18)

Containing a solvent containing sultam shown in Chemical Formula 1 ,
Electrolyte for lithium secondary battery .

The content of the sultam in the solvent is 0.01% by mass or more and 15% by mass or less .
The electrolyte for a lithium secondary battery according to claim 1. The solvent further includes a cyclic carbonate derivative having a halogen atom ,
The electrolyte for a lithium secondary battery according to claim 1. The solvent includes the compound shown in Chemical Formula 2 ,
The electrolyte for a lithium secondary battery according to claim 1.

(R3, R4, R5 and R6 each represents a methyl group, an ethyl group or a group obtained by substituting at least a part of hydrogen with a fluorine group or a chlorine group, or a hydrogen group, a fluorine group or a chlorine group. R3, R4 , R5 and R6 are halogen-containing groups.) The solvent further comprises 4-fluoro-1,3-dioxolan-2-one ,
The electrolyte for a lithium secondary battery according to claim 1. The solvent further includes a cyclic carbonate of an unsaturated compound .
The electrolyte for a lithium secondary battery according to claim 1. Further, the light metal salt shown in Chemical formula ₃ , LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , the lithium salt shown in Chemical formula 4, the lithium salt shown in Chemical formula 5, the cyclic imide salt shown in Chemical formula ₆ and Chemical formula 7 Including at least one member selected from the group consisting of the cyclic imide salts shown in FIG .
The electrolyte for a lithium secondary battery according to claim 1.

(R11 represents a -C (= O) -R21-C (= O)-group (R21 represents an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group), or -C (= O). -C (R23) (R24)-group (R23 and R24 represent an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group), or -C (= O) -C (= O)- R12 represents a halogen group, an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group, X11 and X12 each represents oxygen (O) or sulfur (S), and M11 represents a transition. It represents a metal element or a group 3B element, a group 4B element or a group 5B element in the short periodic table, and M21 represents a group 1A element, a group 2A element or an element in the short period periodic table. Represents Miniumu (Al), a is an integer from 1 4, b is an integer from 0 to 8, c, d, e and f are the respective 1 3 integer.)

(M and n are integers of 1 or more.)

(P, q and r are integers of 1 or more)

(M1 represents a group 1A element, a group 2A element or aluminum in the short periodic table. R7 represents a linear or branched alkylene group having 2 to 5 carbon atoms, or at least a part of hydrogen atoms thereof as fluorine. And t is 1, 2 or 3.

(M2 represents a group 1A element, a group 2A element or aluminum in the short periodic table. R8 represents a linear or branched alkylene group having 2 to 5 carbon atoms, or at least a part of hydrogen atoms thereof. Represents a group substituted with fluorine, u is 1, 2 or 3) Furthermore, the compound shown in Chemical formula 8 is included ,
The electrolyte for a lithium secondary battery according to claim 1.

(R11 represents a -C (= O) -R21-C (= O)-group (R21 represents an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group), or -C (= O). -C (R23) (R24)-group (R23 and R24 represent an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group), or -C (= O) -C (= O)- R13 represents a halogen group, M12 represents phosphorus (P) or boron (B), M21 represents a Group 1A element, a Group 2A element or aluminum in the short-period periodic table, and a1 is 1 And b1 is 0, 2 or 4, and c, d, e and f are each an integer of 1 to 3.) Further, lithium difluoro [oxolato-O, O ′] lithium borate shown in Chemical formula 9, lithium tetrafluoro [oxolato-O, O ′] lithium shown in Chemical formula 10, difluorobis [oxolato-O shown in Chemical formula 11 , O ′] lithium phosphate, difluoro [3,3,3-trifluoro-2-oxide-2-trifluoromethylpropionate (2-)-O, O ′] lithium borate shown in Chemical formula 12, Bis [3,3,3-trifluoro-2-oxide-2-trifluoromethylpropionate (2-)-O, O ′] lithium borate shown in 13 and bis [oxolato- O, O ′] comprising at least one member of the group consisting of lithium borate ,
The electrolyte for a lithium secondary battery according to claim 1.

An electrolyte is provided with a positive electrode and a negative electrode ,
The electrolyte contains a solvent containing sultam shown in Chemical Formula 15 ,
Lithium secondary battery.

The content of the sultam in the solvent is 0.01% by mass or more and 15% by mass or less .
The lithium secondary battery according to claim 10. The solvent further includes a cyclic carbonate derivative having a halogen atom ,
The lithium secondary battery according to claim 10. The solvent includes the compound shown in Chemical formula 16 ,
The lithium secondary battery according to claim 10.

(R3, R4, R5 and R6 each represents a methyl group, an ethyl group or a group obtained by substituting at least a part of hydrogen with a fluorine group or a chlorine group, or a hydrogen group, a fluorine group or a chlorine group. R3, R4 , R5 and R6 are halogen-containing groups.) The solvent further comprises 4-fluoro-1,3-dioxolan-2-one ,
The lithium secondary battery according to claim 10. The solvent further includes a cyclic carbonate of an unsaturated compound .
The lithium secondary battery according to claim 10. The electrolyte includes a light metal salt represented by Chemical Formula 17, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , a lithium salt represented by Chemical Formula 18, a lithium salt represented by Chemical Formula 19, a cyclic imide salt represented by Chemical Formula 20 and Including at least one member selected from the group consisting of cyclic imide salts shown in Chemical Formula 21 ,
The lithium secondary battery according to claim 10.

(R11 represents a -C (= O) -R21-C (= O)-group (R21 represents an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group), or -C (= O). -C (R23) (R24)-group (R23 and R24 represent an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group), or -C (= O) -C (= O)- R12 represents a halogen group, an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group, X11 and X12 each represents oxygen (O) or sulfur (S), and M11 represents a transition. It represents a metal element or a group 3B element, a group 4B element or a group 5B element in the short periodic table, and M21 represents a group 1A element, a group 2A element or an element in the short period periodic table. Represents Miniumu (Al), a is an integer from 1 4, b is an integer from 0 to 8, c, d, e and f are the respective 1 3 integer.)

(M and n are integers of 1 or more.)

(P, q and r are integers of 1 or more)

(M1 represents a group 1A element, a group 2A element or aluminum in the short periodic table. R7 represents a linear or branched alkylene group having 2 to 5 carbon atoms, or at least a part of hydrogen atoms thereof as fluorine. And t is 1, 2 or 3.

(M2 represents a group 1A element, a group 2A element or aluminum in the short periodic table. R8 represents a linear or branched alkylene group having 2 to 5 carbon atoms, or at least a part of hydrogen atoms thereof. Represents a group substituted with fluorine, u is 1, 2 or 3) The electrolyte further includes a compound represented by Chemical Formula 22 :
The lithium secondary battery according to claim 10.

(R11 represents a -C (= O) -R21-C (= O)-group (R21 represents an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group), or -C (= O). -C (R23) (R24)-group (R23 and R24 represent an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group), or -C (= O) -C (= O)- R13 represents a halogen group, M12 represents phosphorus (P) or boron (B), M21 represents a Group 1A element, a Group 2A element or aluminum in the short-period periodic table, and a1 is 1 And b1 is 0, 2 or 4, and c, d, e and f are each an integer of 1 to 3.) The electrolyte further includes difluoro [oxolato-O, O ′] lithium borate shown in Chemical Formula 23, tetrafluoro [oxolato-O, O ′] lithium phosphate shown in Chemical Formula 24, difluorobis shown in Chemical Formula 25. [Oxolato-O, O ′] lithium phosphate, difluoro [3,3,3-trifluoro-2-oxide-2-trifluoromethylpropionate (2-)-O, O ′] boro Lithium acid, bis [3,3,3-trifluoro-2-oxide-2-trifluoromethylpropionate (2-)-O, O ′] lithium borate shown in Chemical Formula 27, and Chemical formula 28 Including at least one member of the group consisting of lithium bis [oxolato-O, O ′] lithium borate ,
The lithium secondary battery according to claim 10 .

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