JP5044967B2 - Secondary battery electrolyte and secondary battery - Google Patents

Description

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

  In recent years, portable electronic devices typified by camera-integrated VTR (Videotape Recorder), mobile phones or laptop computers have become widespread, and their miniaturization, weight reduction, and long-term continuous driving have been strongly demanded. Yes. Accordingly, research and development for improving the energy density of batteries, in particular, secondary batteries, are being actively promoted as portable power sources for these electronic devices. Among these, lithium ion secondary batteries or lithium metal secondary batteries are expected because they can obtain a larger energy density than conventional secondary batteries such as lead batteries or nickel cadmium batteries.

In such a lithium ion secondary battery or a lithium metal secondary battery, an electrolyte obtained by dissolving LiPF ₆ as an electrolyte salt in a carbonate ester-based nonaqueous solvent such as propylene carbonate or diethyl carbonate has high conductivity and potential. Is also widely used since it is stable (see, for example, Patent Document 1).
Japanese Patent No. 3294400

  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 secondary battery that can improve battery characteristics even at a high temperature, and a secondary battery using the same.

Secondary battery electrolyte of the present invention includes a scan sulfone compound contains a solvent comprising a cyclic carbonate derivative having halogen atom, and sulfonic compounds showed to formula 1 below (1) to (8) The cyclic carbonate derivative containing at least one member selected from the group consisting of and having a halogen atom includes the compound shown in Chemical Formula 3 below .

Secondary battery of the present invention includes a positive electrode and an electrolyte with an anode, the electrolyte contains a scan sulfone compound, a solvent containing a cyclic carbonate derivative having halogen atom, sulfone compounds, described later of 1 ( The cyclic carbonate derivative containing at least one member selected from the group consisting of the compounds shown in 1) to (8) and having a halogen atom includes the compound shown in Chemical Formula 3 described later .

According to an electrolyte for a secondary battery of the present invention, a scan sulfone compound. Thus including a cyclic carbonate derivative having halogen atoms, even under a high temperature environment, to improve the chemical stability Can do. Therefore, according to the secondary battery of the present invention using the electrolyte for the secondary battery, the decomposition reaction of the electrolyte in the negative electrode can be suppressed even in a high temperature environment. Excellent properties can be obtained even when used under circumstances.

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

  The electrolyte according to one embodiment of the present invention contains, for example, an electrolytic solution containing a solvent and an electrolyte salt dissolved in the solvent.

  The solvent contains a cyclic sulfone compound having an O═S═O bond and having at least one carbon having an unsaturated bond bonded to a sulfur atom. Thereby, chemical stability can be improved even in a high temperature environment. A sulfone compound may be used individually by 1 type, and multiple types may be mixed and used for it.

  As such a sulfone compound, compounds represented by Chemical formula (1) to Chemical formula (1) are preferable. This is because a higher effect can be obtained.

（式中、Ｒ１，Ｒ１０，Ｒ１５およびＲ１６は、−ＣＨ₂ −あるいは炭素数６以下のアルキレン基、またはこれらの少なくとも一部の水素（Ｈ）をアリル基，ビニレン基およびアリール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。Ｒ１，Ｒ１０，Ｒ１５およびＲ１６は、直鎖状であってもよいし、分岐状であってもよい。Ｒ２，Ｒ３，Ｒ４，Ｒ５，Ｒ６，Ｒ７，Ｒ８，Ｒ９，Ｒ１１，Ｒ１２，Ｒ１３，Ｒ１４，Ｒ１７，Ｒ１８，Ｒ１９，Ｒ２０，Ｒ２１，Ｒ２２，Ｒ２３，Ｒ２４，Ｒ２５，Ｒ２６，Ｒ２７およびＲ２８は、アルキル基，アリル基，アリール基，アラルキル基，アルコキシアルキル基あるいはこれらの少なくとも一部の水素をハロゲンで置換した基、または水素基、またはハロゲン基を表す。Ｒ２，Ｒ３，Ｒ４，Ｒ５，Ｒ６，Ｒ７，Ｒ８，Ｒ９，Ｒ１１，Ｒ１２，Ｒ１３，Ｒ１４，Ｒ１７，Ｒ１８，Ｒ１９，Ｒ２０，Ｒ２１，Ｒ２２，Ｒ２３，Ｒ２４，Ｒ２５，Ｒ２６，Ｒ２７およびＲ２８は、互いに同一であってもよいし、異なっていてもよい。）

(In the formula, R1, R10, R15 and R16 are —CH ₂ — or an alkylene group having 6 or less carbon atoms, or at least a part of hydrogen (H) of the group consisting of an allyl group, a vinylene group and an aryl group. R1, R10, R15 and R16 may be linear or branched, and may be substituted with R2, R3, R4, R5, R6, R7. , R8, R9, R11, R12, R13, R14, R17, R18, R19, R20, R21, R22, R23, R24, R25, R26, R27 and R28 are alkyl groups, allyl groups, aryl groups, aralkyl groups, R2, R3, R4 represents an alkoxyalkyl group or a group obtained by substituting at least a part of hydrogen with a halogen, a hydrogen group, or a halogen group. R5, R6, R7, R8, R9, R11, R12, R13, R14, R17, R18, R19, R20, R21, R22, R23, R24, R25, R26, R27 and R28 may be the same as each other. And may be different.)

  As the compounds represented by Chemical formula 1 (1) to Chemical formula 1 (8), 4-membered or 5-membered ring compounds are more preferred. Specific examples include Chemical formula 2 (1) to Chemical formula 2 ( 54).

  The content of such a sulfone compound is preferably 0.01% by mass or more and 10% by mass or less in the solvent. This is because a higher effect can be obtained within this range.

  In addition to these sulfone compounds, the solvent preferably contains a cyclic carbonate derivative having a halogen atom, and among them, the cyclic carbonate derivative shown in Chemical Formula 3 is desirable. This is because the chemical stability of the electrolytic solution can be improved not only at room temperature but also in a high temperature environment. A cyclic carbonate derivative may be used individually by 1 type, and may mix and use multiple types.

（Ｒ５１，Ｒ５２，Ｒ５３およびＲ５４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をフッ素（Ｆ），塩素（Ｃｌ）若しくは臭素（Ｂｒ）で置換した基、または水素、またはフッ素基、または塩素基、または臭素基を表す。Ｒ５１，Ｒ５２，Ｒ５３およびＲ５４のうちの少なくとも一つはハロゲンを有する基である。Ｒ５１，Ｒ５２，Ｒ５３およびＲ５４は、互いに同一であってもよいし、異なっていてもよい。）

(R51, R52, R53 and R54 are a methyl group, an ethyl group, or a group in which at least a part of hydrogen is substituted with fluorine (F), chlorine (Cl) or bromine (Br), hydrogen, or a fluorine group, or Represents a chlorine group or a bromine group, wherein at least one of R51, R52, R53 and R54 is a halogen-containing group, and R51, R52, R53 and R54 may be the same or different; May be.)

  Specific examples of the cyclic carbonate derivative shown in Chemical formula 3 include the compounds shown in Chemical formula 4 (1) to Chemical formula 4 (26). Of these, 4-fluoro-1,3-dioxolan-2-one shown in Chemical Formula 4 (1) is preferable. This is because a higher effect can be obtained.

  As the solvent, an unsaturated bond such as 1,3-dioxol-2-one shown in Chemical formula 5 (1) or 4-vinyl-1,3-dioxolan-2-one shown in Chemical formula 5 (2) is used. A cyclic ester carbonate is also preferred. This is because the chemical stability of the electrolytic solution can be improved and a high effect can be obtained even at high temperatures. When the solvent contains a cyclic carbonate having an unsaturated bond, the content is preferably in the range of 0.01% by mass to 10% by mass. This is because a higher effect can be obtained within these ranges. The cyclic carbonate having an unsaturated bond may be used alone or in combination of two or more.

  In addition to these solvents, for example, 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, Examples thereof include N-dimethylformamide, N-methylpyrrolidinone, N-methyloxazolidinone, N, N′-dimethylimidazolidinone, nitromethane, nitroethane, sulfolane, dimethyl sulfoxide, and trimethyl phosphate. These solvents may be used alone or in combination of two or more.

  The electrolyte salt preferably contains a light metal salt shown in Chemical formula 6. This is because, for example, this light metal salt can form a stable film on the surface of the negative electrode 22, suppress the decomposition reaction of the solvent, and improve battery characteristics such as cycle characteristics. The light metal salt shown in Chemical Formula 6 may be used alone or in combination of two or more.

（Ｒ３１は、化７，化８または化９に示した基を表し、Ｒ３２は、ハロゲン，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（Ｏ）または硫黄をそれぞれ表し、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、Ｍ１１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（Ａｌ）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。）

(R31 represents the group shown in Chemical formula 7, Chemical formula 8 or Chemical formula 9, R32 represents a halogen, an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group, and X11 and X12 represent oxygen (O 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 M11 represents a group 1A element or a group 2A element in the short period periodic table. Or represents aluminum (Al), 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.)

（Ｒ４１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。）

(R41 represents an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group.)

（Ｒ４３，Ｒ４４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。Ｒ４３，Ｒ４４は、同一であっても異なっていてもよい。）

(R43 and R44 each represents an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group. R43 and R44 may be the same or different.)

  As the light metal salt shown in Chemical formula 6, for example, the compound shown in Chemical formula 10 is preferable.

（Ｒ３１は、化１１，化１２または化１３に示した基を表し、Ｒ３３は、ハロゲンを表し、Ｍ１２は、リン（Ｐ）またはホウ素（Ｂ）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。）

(R31 represents the group shown in Chemical Formula 11, Chemical Formula 12, or Chemical Formula 13, R33 represents halogen, M12 represents phosphorus (P) or boron (B), and M21 represents 1A in the short periodic table. A1 is an integer of 1 to 3, b1 is 0, 2 or 4, and c, d, e and f are each an integer of 1 to 3)

（Ｒ４１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。）

(R41 represents an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group.)

（Ｒ４３，Ｒ４４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。Ｒ４３，Ｒ４４は、同一であっても異なっていてもよい。）

(R43 and R44 each represents an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group. R43 and R44 may be the same or different.)

  Specific examples of such compounds include lithium difluoro [oxolato-O, O ′] lithium borate shown in Chemical formula 14 (1), and tetrafluoro [oxolato-O, O shown in chemical formula 14 (2). '] Lithium phosphate, difluorobis [oxolato-O, O ′] lithium phosphate shown in Chemical formula 14 (3), difluoro [3,3,3-trifluoro-2-oxide shown in chemical formula 14 (4) 2-trifluoromethylpropionate (2-)-O, O ′] lithium borate, bis [3,3,3-trifluoro-2-oxide-2-trifluoromethyl represented by Chemical formula 14 (5) Examples include lithium propionate (2-)-O, O ′] lithium borate or bis [oxolato-O, O ′] lithium borate shown in Chemical formula 14 (6).

As the electrolyte salt, LiPF ₆ , 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 SO ₂ ) or a lithium salt shown in Chemical Formula 16 such as LiC (CF ₃ SO ₂ ) ₃ or a cyclic imide salt shown in Chemical Formula 17 or a cyclic salt shown in Chemical Formula 18 Imide salts are also preferred.

（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。Ｒ２９は、炭素数２から５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。Ｒ２９は、直鎖状であってもよいし、分岐状であってもよい。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. R29 represents an alkylene group having 2 to 5 carbon atoms, or a group obtained by substituting at least a part of hydrogen with fluorine. R29 may be linear or branched. 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。Ｒ３０は、炭素数２から５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。Ｒ３０は、直鎖状であってもよいし、分岐状であってもよい。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-period type periodic table. R30 represents an alkylene group having 2 to 5 carbon atoms, or a group in which at least a part of hydrogen is substituted with fluorine. R30 may be linear or branched. U is 1, 2 or 3.)

  Examples of the cyclic imide salt shown in Chemical formula 17 and the cyclic imide salt shown in Chemical formula 18 include 1,2-perfluoroethanedisulfonylimide lithium shown in Chemical formula 19 (1), and Chemical formula 19 (2). 1,3-perfluoropropanedisulfonylimide lithium shown, 1,3-perfluorobutanedisulfonylimide lithium shown in Chemical formula 19 (3), 1,4-perfluorobutanedi shown in Chemical formula 19 (4) Examples thereof include sulfonylimidolithium and lithium perfluoroheptanenic acid imidolith shown in Chemical formula 19 (5). These cyclic imide salts may be used alone or in combination of two or more.

In particular, LiPF ₆ , light metal salt shown in Chemical formula ₆ , LiClO ₄ , LiAsF ₆ , lithium salt shown in Chemical formula 15, lithium salt shown in Chemical formula 16, cyclic imide salt shown in Chemical formula 17 and Chemical formula 18 It is preferable to use a mixture of at least one selected from the group consisting of the cyclic imide salts shown. This is because the ion conductivity can be improved and the chemical stability of the electrolytic solution can be improved not only at room temperature but also in a high temperature environment.

In addition to these, examples of the electrolyte salt include LiB (C ₆ H ₅ ) ₄ , LiCH ₃ SO ₃ , LiCF ₃ SO ₃ , LiAlCl ₄ , LiSiF ₆ , LiCl or LiBr, and one kind is used alone. Alternatively, a plurality of types may be mixed and used.

  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 6 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.

  This electrolytic solution is used for a secondary battery as follows, for example.

(First secondary battery)
FIG. 1 shows a cross-sectional structure of the first secondary battery. This secondary battery is a so-called lithium ion secondary battery in which lithium (Li) 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 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 an electrode reactant 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. One positive electrode material may be used alone, or a plurality of positive electrode materials 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 or one surface of a negative electrode current collector 22A having a pair of opposed surfaces. The negative electrode current collector 22A is made of, for example, a metal material such as copper, 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 (Sn) or silicon (Si) 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.

  Examples of tin alloys include silicon, nickel, copper (Cu), iron, cobalt (Co), manganese (Mn), zinc (Zn), indium (In), and silver as second constituent elements other than tin. (Ag), titanium (Ti), germanium (Ge), bismuth (Bi), antimony (Sb), and the thing containing at least 1 sort (s) of chromium (Cr) are mentioned. 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, gallium (Ga) or bismuth are preferable, and two or more kinds are included. May be included. 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 artificial graphite, natural graphite, graphitized carbon fiber, graphitized mesocarbon microbeads, fullerene, and amorphous carbon. 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.

  The separator 23 is impregnated with the above-described electrolytic solution. Thereby, the decomposition reaction of the electrolyte can be suppressed even at a high temperature. Therefore, excellent characteristics can be obtained even when left under high temperature conditions or when used under high temperature conditions.

  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 released from the positive electrode 21 and inserted in the negative electrode 22 through the electrolyte. When discharging is performed, for example, lithium ions are released from the negative electrode 22 and inserted into the positive electrode 21 through the electrolyte. At that time, since the electrolyte includes a cyclic sulfone compound having an O═S═O bond and at least one carbon having an unsaturated bond bonded to a sulfur atom, the electrolyte can be used even at a high temperature. Decomposition reaction is suppressed.

  As described above, according to the electrolyte of the present embodiment, the cyclic sulfone compound having an O═S═O bond and having at least one carbon having an unsaturated bond bonded to a sulfur atom is included. Chemical stability can be improved even in a high temperature environment. Therefore, according to the first secondary battery using this electrolyte, the decomposition reaction of the electrolyte in the negative electrode can be suppressed even in a high temperature environment, and it can be used under a high temperature condition even if left under a high temperature condition. Even so, excellent characteristics can be obtained.

(Secondary secondary battery)
The second secondary battery has the same configuration and operation as the first secondary battery except that the configuration of the negative electrode is different, and 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.

  Similar to the first secondary battery, 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. 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 secondary battery)
The third secondary battery is a so-called lithium metal secondary battery in which the capacity of the negative electrode is represented by a capacity component due to precipitation and dissolution of lithium.

  This secondary battery has the same configuration and effects as those of the first or second secondary battery 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 first secondary battery.

  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 electrolyte, 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 electrolyte. At that time, since the electrolyte includes a cyclic sulfone compound having an O═S═O bond and at least one carbon having an unsaturated bond bonded to a sulfur atom, the electrolyte can be used even at a high temperature. Decomposition reaction is suppressed.

  Thus, the third secondary battery also includes a cyclic sulfone compound in which the electrolyte has an O═S═O bond, and the sulfur atom is bonded to at least one carbon having an unsaturated bond. Even if it is left under a high temperature condition or used under a high temperature condition, excellent characteristics can be obtained.

(Fourth secondary battery)
FIG. 3 shows the configuration of the fourth secondary battery. 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 those in the first to third secondary batteries 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 includes the above-described electrolytic solution and a polymer compound that serves as a holding body that holds the electrolytic solution, and has a so-called gel shape. A gel electrolyte is preferable because high ion conductivity can be obtained and battery leakage can be prevented. Examples of the polymer compound include polyacrylonitrile, polyvinylidene fluoride, a copolymer of vinylidene fluoride and hexafluoropropylene, polytetrafluoroethylene, polyhexafluoropropylene, polyethylene oxide, polypropylene oxide, polyphosphazene, and polysiloxane. , Polyvinyl acetate, polyvinyl alcohol, polymethyl methacrylate, polyacrylic acid, polymethacrylic acid, styrene-butadiene rubber, nitrile-butadiene rubber, polystyrene or polycarbonate. In particular, from the viewpoint of electrochemical stability, it is desirable to use a polymer compound having a polyacrylonitrile, polyvinylidene fluoride, polyhexafluoropropylene or polyethylene oxide structure.

  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.

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

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

( Reference Examples 1-1 to 1-7, Examples 1-8 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.

  Also, after preparing 90 parts by mass of artificial graphite powder, which is a carbon material as a negative electrode active material, and 10 parts by mass of polyvinylidene fluoride as a binder, a negative electrode mixture was prepared, and then N-methyl-2- A negative electrode mixture slurry was prepared by dispersing in pyrrolidone. Subsequently, the 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 and dried, and then compression molded by a roll press 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 producing the positive electrode 33 and the negative electrode 34, it laminated | stacked through the separator 35 so that the positive electrode 33 and the negative electrode 34 might oppose, and it wound and formed the wound body which is the precursor of the wound electrode body 30. FIG.

  The obtained wound body is sandwiched between exterior members 40 made of a laminate film, and the outer peripheral edge except one side is heat-sealed to be stored in a bag shape inside the exterior member 40, and the electrolytic solution is contained inside the exterior member 40. Injected into. The laminate film was made of nylon-aluminum-unstretched polypropylene from the outside, and the thickness was 30 μm, 40 μm, and 30 μm, respectively, and the total was 100 μm.

In Reference Examples 1-1, 1-4 to 1-7, the electrolytic solution was prepared by mixing ethylene carbonate (EC), diethyl carbonate (DEC), a cyclic sulfone compound, and LiPF ₆ as an electrolyte salt as solvents. Made. At that time, the mixing ratio (mass ratio) of ethylene carbonate and diethyl carbonate was ethylene carbonate: diethyl carbonate = 2: 3. The content of the cyclic sulfone compound in the solvent was 2% by mass, and the concentration of LiPF ₆ in the electrolytic solution was 1.0 mol / kg. Furthermore, cyclic sulfone compound, compounds described in Reference Examples 1-1 In Formula 2 (11) and (fame 2,3-dihydro-thiophene 1,1-dioxide ), Reference Example 1-4 In the formula 2 (52 ) (English name Benzo [b] thiophenel1,1-dioxide). In Reference Example 1-5, the compound shown in Chemical formula 2 (54) (English name 3, Bromo-2,3-dihydro-thiophen 1,1 -dioxide), and in Reference Example 1-6, the compound shown in Chemical Formula 2 (23) (English name 3, Fluoro-2,3-dihydro-thiophene 1,1-dioxide) was used, and in Reference Example 1-7, Chemical Formula 2 ( 31) (English name 3,4-Dihydro-2H-thiophene 1,1-dioxide). These cyclic sulfone compounds have an O═S═O bond, and at least one carbon having an unsaturated bond is bonded to a sulfur atom.

In Reference Examples 1-2 and 1-3, ethylene carbonate, diethyl carbonate, a cyclic sulfone compound, a cyclic carbonate having an unsaturated bond, and LiPF ₆ as an electrolyte salt are mixed as solvents. An electrolytic solution was prepared. At that time, the mixing ratio (mass ratio) of ethylene carbonate and diethyl carbonate was ethylene carbonate: diethyl carbonate = 2: 3. The content of the cyclic sulfone compound in the solvent was 2% by mass, and the concentration of LiPF _{6 in} the electrolytic solution was 1.0 mol / kg. Further, the cyclic sulfone compound was the compound shown in Chemical Formula 2 (11) (English name 2,3-dihydro-thiophene 1,1-dioxide). In addition, carbonic acid ester of an annular having an unsaturated bond, and in Reference Example 1-2 1,3-dioxole-2-one (VC), Reference Example 1-3 In the 4-vinyl-1,3-dioxolane - 2-one (VEC) was used, and the content in the solvent was 1% by mass.

In Examples 1-8 to 1-14, 4-fluoro-1,3-dioxolan-2-one (FEC), which is a cyclic carbonate derivative having a halogen atom, was used instead of ethylene carbonate. Except for the above, electrolyte solutions were prepared in the same manner as Reference Examples 1-1 to 1-7.

  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, an electrolytic solution and a secondary battery were produced in the same manner as Reference Examples 1-1 and 1-4 to 1-7, except that the cyclic sulfone compound was not used.

In Comparative Example 1-2, except that the compound shown in Chemical Formula 20 (English name 2,5-dihydro-thiophene 1,1-dioxide) was used as the cyclic sulfone compound, Reference Example 1-1, 1 was otherwise used. The electrolytic solution and the secondary battery were produced in the same manner as in -4 to 1-7. The compound shown in Chemical formula 20 is a compound in which a carbon having an unsaturated bond is not bonded to a sulfur atom.

In Comparative Example 1-3, an electrolytic solution and a secondary battery were produced in the same manner as Reference Example 1-2 except that the cyclic sulfone compound was not used.

  In Comparative Example 1-4, an electrolytic solution and a secondary battery were produced in the same manner as in Examples 1-8 and 1-11 to 1-14 except that the cyclic sulfone compound was not used.

  In Comparative Example 1-5, an electrolytic solution and a secondary battery were produced in the same manner as in Example 1-9 except that the cyclic sulfone compound was not used.

Regarding the fabricated secondary batteries of Reference Examples 1-1 to 1-7, Examples 1-8 to 1-14 and Comparative Examples 1-1 to 1-5, the high-temperature storage characteristics and the high-temperature cycle characteristics were as follows. Examined.

  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 an upper limit voltage of 4.2 V, and the discharge was 0.2 C constant current discharge to a final voltage of 2.5 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 an upper limit voltage of 4.2 V, and the discharge was 0.2 C constant current discharge to a final voltage of 2.5 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, Reference Examples 1-1 and 1-4 using a cyclic sulfone compound having an O═S═O bond and having at least one carbon having an unsaturated bond bonded to a sulfur atom. According to ˜1-7, higher temperature storage characteristics than Comparative Example 1-1 not containing this or Comparative Example 1-2 using a cyclic sulfone compound in which a carbon having an unsaturated bond to a sulfur atom is not bonded. Alternatively, the high temperature cycle characteristics were improved. Similarly, in Reference Example 1-2 using 1,3-dioxol-2-one, the high-temperature storage characteristics or the high-temperature cycle characteristics were improved as compared with Comparative Example 1-3. Furthermore, according to Reference Examples 1-2 and 1-3 using a cyclic carbonate having an unsaturated bond, the warm storage characteristics or the high-temperature cycle characteristics were improved as compared with Reference Example 1-1 in which this was not used. .

In addition, according to Examples 1-8 to 1-14 using a cyclic carbonate derivative having a halogen atom, the same results as in Reference Examples 1-1 to 1-7 were obtained, and the cyclic carbonate derivative was obtained. As a result, the high-temperature storage characteristics or the high-temperature cycle characteristics were further improved as compared with Reference Examples 1-1 to 1-7.

  That is, if the electrolyte solution contains a cyclic sulfone compound having an O═S═O bond and at least one carbon having an unsaturated bond bonded to a sulfur atom, the electrolyte solution is left under high temperature conditions. Even when used under high temperature conditions, excellent characteristics can be obtained, and it is preferable if a cyclic carbonate derivative having a halogen atom or a cyclic carbonate having an unsaturated bond is included. I understood.

( Reference Examples 2-1 to 2-7, Examples 2-8 to 2-14, Reference Examples 3-1 to 3-5, Examples 3-6 to 3-10)
In Reference Examples 2-1 to 2-7 and Examples 2-8 to 2-14, silicon was used as the negative electrode active material, and the negative electrode current collector 34A made of a copper foil having a thickness of 15 μm was used by an electron beam evaporation method. A secondary battery was fabricated in the same manner as in Reference Examples 1-1 to 1-7 and Examples 1-8 to 1-14 , except that the negative electrode active material layer 34B made of silicon was formed. At that time, the capacity of the negative electrode was expressed by a capacity component due to insertion and extraction of lithium.

In Reference Examples 3-1 to 3-5 and Examples 3-6 to 3-10, CoSnC-containing material powder was used as the negative electrode active material, and 80 parts by mass of the CoSnC-containing material powder and the negative electrode active material and conductive material were also used. 11 parts by mass of graphite, 1 part by mass of acetylene black, and 8 parts by mass of polyvinylidene fluoride as a binder were dispersed in N-methyl-2-pyrrolidone as a solvent. Except that the negative electrode current collector 34A was uniformly applied and dried, and molded at a constant pressure to form the negative electrode active material layer 34B, the other examples were carried out in Reference Examples 1-1 to 1-4, 1-6. Secondary batteries were fabricated in the same manner as in Examples 1-8 to 1-11, 1-13. At that time, the capacity of the negative electrode was expressed by a capacity component due to insertion and extraction of lithium.

  The CoSnC-containing material powder was synthesized by mixing a tin / cobalt 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 49.5% by mass, the content of cobalt was 29.7% by mass, the content of carbon was 19.8% by mass, The ratio Co / (Sn + Co) of cobalt to the total with cobalt was 37.5% 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 ° or more was observed between the diffraction angle 2θ = 20 ° and 50 °. 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.

Comparative Examples 2-1 to 2-5 to Reference Examples 2-1 to 2-7, Examples 2-8 to 2-14, Reference Examples 3-1 to 3-5, and Examples 3-6 to 3-10 As 3-1 to 3-5, Reference Example 2-1 to 2-7 and Examples 2-8 to 2 are the same except that the same electrolytic solution as Comparative Examples 1-1 to 1-5 was used. 14, Referential batteries were produced in the same manner as in Reference Examples 3-1 to 3-5 and Examples 3-6 to 3-10, respectively.

About the secondary battery of each Example and each comparative example, the high temperature storage characteristic and the high temperature cycling characteristic were investigated like reference example 1-1-1-7 and Example 1-8-1-14 . The results are shown in Tables 2 and 3.

As shown in Tables 2 and 3, the same results as Reference Examples 1-1 to 1-7 and Examples 1-8 to 1-14 were obtained. That is, even when other negative electrode active materials are used, the electrolyte solution contains a cyclic sulfone compound having an O═S═O bond and at least one carbon having an unsaturated bond bonded to a sulfur atom. Thus, it is possible to obtain excellent characteristics whether it is left under a high temperature condition or used under a high temperature condition, and a cyclic carbonate ester derivative having a halogen atom or a cyclic carbonate ester having an unsaturated bond. It has been found that it is preferable to include.

( Reference Examples 4-1 to 4-7, Examples 4-8 to 4-14)
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. Specifically, lithium metal was used as the negative electrode active material, and the negative electrode active material layer 34B was formed by pasting 30 μm thick lithium metal to the negative electrode current collector 34A made of a strip-shaped copper foil having a thickness of 15 μm. Others were fabricated in the same manner as Reference Examples 1-1 to 1-7 and Examples 1-8 to 1-14.

As Comparative Examples 4-1 to 4-5 for Reference Examples 4-1 to 4-7 and Examples 4-8 to 4-14, the same electrolytic solution as Comparative Examples 1-1 to 1-5 was used. Except for this, secondary batteries were fabricated in the same manner as Reference Examples 4-1 to 4-7 and Examples 4-8 to 4-14.

Fabricated Reference Example 4-1 4-7, the secondary batteries of Examples 4-8～ 4-14 and Comparative Examples 4-1 to 4-5, Reference Example 1-1 1-7 Example 1 High temperature storage characteristics and high temperature cycle characteristics were examined in the same manner as in -8 to 1-14. The results are shown in Table 4.

As shown in Table 4, the same results as in Reference Examples 1-1 to 1-7 and Examples 1-8 to 1-14 were obtained. That is, even in the case of a lithium metal secondary battery in which the capacity of the negative electrode is represented by a capacity component due to precipitation and dissolution of lithium, the electrolytic solution has an O═S═O bond, and the sulfur atom has an unsaturated bond. If a cyclic sulfone compound to which at least one carbon having a carbon atom is bonded is included, excellent characteristics can be obtained even if the carbon is left under a high temperature condition or used under a high temperature condition. It has been found that it is preferable to include a cyclic carbonate derivative having a cyclic carbonate having an unsaturated bond.

( Reference Examples 5-1 to 5-3, Examples 5-4 to 5-6, Reference Examples 6-1 to 6-3, Examples 6-4 to 6-6, Reference Examples 7-1 to 7-3 , Examples 7-4 to 7-6, Reference Examples 8-1 to 8-3, Examples 8-4 to 8-6)
Except that the content of the compound (English name 2,3-dihydro-thiophene 1,1-dioxide) shown in Chemical Formula 2 (11) in the solvent was 0.01 mass%, 5 mass% or 10 mass%, Others are Reference Example 1-1, Example 1-8, Reference Example 2-1, Example 2-8, Reference Example 3-1, Example 3-6, Reference Example 4-1, and Example 4-8. Secondary batteries were produced in the same manner.

About each produced secondary battery , it carried out similarly to Reference Examples 1-1 to 1-7, and Examples 1-8 to 1-14, and investigated the high temperature storage characteristic and the high temperature cycling characteristic. The results are shown in Tables 5-8.

  As shown in Tables 5 to 8, when the content of the compound shown in Chemical Formula 2 (11) is in the range of 0.01% by mass to 10% by mass, both the high temperature storage characteristics and the high temperature cycle characteristics are high. was gotten.

  That is, it has been found that it is preferable that the content of the cyclic sulfone compound in the solvent is 0.01% by mass or more and 10% by mass or less.

( Reference Examples 9-1 to 9-11, 10-1 to 10-11, 11-1 to 11-7, 12-1 to 12-11)
As an electrolyte salt, in addition to LiPF ₆ , the dimetal [oxolato-O, O ′] lithium borate shown in Chemical formula 14 (1) which is a light metal salt shown in Chemical formula 6 or the light metal salt shown in Chemical formula 6 The bis [oxolato-O, O ′] lithium borate shown in Chemical formula 14 (6), or the bis [oxolato-O, O ′] lithium borate shown in Chemical formula 14 (6) and the cyclic form shown in Chemical formula 17 Reference Example 1-1, 1-4 to 1-7, 2-1, except that 1,3-perfluoropropanedisulfonylimide lithium shown in Chemical Formula 19 (2) which is an imide salt was used. Secondary batteries were fabricated in the same manner as 2-4 to 2-7, 3-1, 3-3, 3-4, 4-1, 4-4 to 4-7. At that time, the concentration of each electrolyte salt in the electrolytic solution was as shown in Tables 9-12.

As Comparative Examples 9-1, 10-1, 11-1, and 12-1, except that a cyclic sulfone compound was not used, others were Reference Examples 9-1 to 9-5 and 10-1 to 10-5. , 11-1 to 11-3, and 12-1 to 12-5, secondary batteries were fabricated.

About each produced secondary battery , it carried out similarly to Reference Examples 1-1 to 1-7, and Examples 1-8 to 1-14, and investigated the high temperature storage characteristic and the high temperature cycling characteristic. The results are shown in Tables 9-12.

As shown in Tables 9 to 12, in addition to LiPF ₆ as a lithium salt, lithium difluoro [oxolato-O, O ′] lithium borate, bis [oxolato-O, O ′] lithium borate, or bis [oxolato Reference Examples 9-1 to 9-11, 10-1 to 10-11, 11-1 to 11-7 using —O, O ′] lithium borate and 1,3-perfluoropropanedisulfonylimide lithium According to 12-1 to 12-11, Reference Examples 1-1, 1-4 to 1-7, 2-1, 2-4 to 2-7, 3-1, 1, 3-3 which do not use them High-temperature storage characteristics or high-temperature cycle characteristics were improved as compared with 3-4, 4-1 and 4-4 to 4-7, respectively. Further, in Reference Examples 9-1, 10-1, 11-1, and 12-1 using a sulfone compound together with lithium difluoro [oxolato-O, O ′] lithium borate, Comparative Example 9-1 that does not use a sulfone compound , 10-1, 11-1, and 12-1, the high temperature storage characteristics or the high temperature cycle characteristics were improved.

That is, LiPF ₆ , light metal salt shown in chemical formula ₆ , LiClO ₄ , LiAsF ₆ , lithium salt shown in chemical formula 15, lithium salt shown in chemical formula 16, cyclic imide salt shown in chemical formula 17 and chemical formula 18 It was found that it was preferable to use at least one member selected from the group consisting of cyclic imide salts.

( Reference Example 13-1, Example 13-2, Reference Example 14-1, Example 14-2, Reference Example 15-1, Example 15-2, Reference Example 16-1, Example 16-2)
The cylindrical secondary battery shown in FIGS. 1 and 2 was produced. First, Reference Examples 1-1 to 1-7, Examples 1-8 to 1-14, Reference Examples 2-1 to 2-7, Examples 2-8 to 2-14, Reference Examples 3-1 to 3- 5, Examples 3-6 to 3-10, Reference Examples 4-1 to 4-7, and Examples 4-8 to 4-12 were produced as positive electrode 21 and negative electrode 22, respectively, and positive electrodes made of aluminum for each. The lead 25 and the nickel negative electrode lead 26 were attached. At that time, in Reference Example 13-1, Example 13-2, Reference Example 14-1, Example 14-2, Reference Example 15-1, and Example 15-2, the capacity of the negative electrode is lithium insertion and extraction. It was made to be represented by the volume component by. In Reference Example 16-1 and Example 16-2, the capacity of the negative electrode was expressed by a capacity component due to precipitation and dissolution of lithium.

  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. The electrolytes used were Reference Example 1-1, Example 1-8, Reference Example 2-1, Example 2-8, Reference Example 3-1, Example 3-6, Reference Example 4-1, Example 4 The same as -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 13-1, 13-2, 14-1, 14-2, 15-1, 15-2, 16-1, and 16-2 for each Example, except that a cyclic sulfone compound was not used. Specifically, except that the same electrolytic solution as in Comparative Examples 1-1, 1-4, 2-1, 2-4, 3-1, 3-4, 4-1, 4-4 was used. The others are Reference Example 13-1, Example 13-2, Reference Example 14-1, Example 14-2, Reference Example 15-1, Example 15-2, Reference Example 16-1, and Example 16-2. A secondary battery was fabricated in the same manner as described above.

About each produced secondary battery , it carried out similarly to Reference Examples 1-1 to 1-7, and Examples 1-8 to 1-14, and investigated the high temperature storage characteristic and the high temperature cycling characteristic. The results are shown in Tables 13-16.

As shown in Table 13 to Table 16, Reference Example 1-1, Example 1-8, Reference Example 2-1, Example 2-8, Reference Example 3-1, Example 3-6, Reference Example 4 -1, the same results as in Example 4-8 were obtained. That is, even in the case of a secondary battery having another shape, a cyclic sulfone compound having an O═S═O bond in an electrolyte, and at least one carbon having an unsaturated bond bonded to a sulfur atom. If it is included, excellent characteristics can be obtained even if it is left under a high temperature condition or used under a high temperature condition, and it is preferable if a cyclic carbonate derivative having a halogen atom is included. I understood that.

( Reference Examples 17-1 to 17-3, 18-1 to 18-3, 19-1 to 19-3, 20-1 to 20-3)
As an electrolyte salt, in addition to LiPF ₆ , the dimetal [oxolato-O, O ′] lithium borate shown in Chemical formula 14 (1) which is a light metal salt shown in Chemical formula 6 or the light metal salt shown in Chemical formula 6 The bis [oxolato-O, O ′] lithium borate shown in Chemical formula 14 (6), or the bis [oxolato-O, O ′] lithium borate shown in Chemical formula 14 (6) and the cyclic form shown in Chemical formula 17 Reference Example 13-1, 14-1, 15-1, 16-1 and others except that 1,3-perfluoropropanedisulfonylimide lithium shown in Chemical Formula 19 (2) which is an imide salt was used Similarly, a secondary battery was produced. Specifically, Reference Examples 9-1, 9-6, 9-11, 10-1, 10-6, 10-11, 11-1, 11-4, 11-7, 12-1, 12-6 , 12-11 was used.

Specifically, as Comparative Examples 17-1, 18-1, 19-1, and 20-1, except that no cyclic sulfone compound was used, Comparative Examples 9-1, 10-1, and 11-1, A secondary battery was fabricated in the same manner as Reference Examples 17-1, 18-1, 19-1, and 20-1, except that the same electrolytic solution as in 12-1 was used.

About each produced secondary battery , it carried out similarly to Reference Examples 1-1 to 1-7, and Examples 1-8 to 1-14, and investigated the high temperature storage characteristic and the high temperature cycling characteristic. The results are shown in Tables 17-20.

As shown in Table 17 to Table 20, Reference Examples 9-1, 9-6, 9-11, 10-1, 10-6, 10-11, 11-1, 11-4, 11-7, 12 Similar results to those of -1,12-6 and 12-11 were obtained. That is, in the case of a secondary battery having another shape, LiPF ₆ , the light metal salt shown in Chemical formula ₆ , LiClO ₄ , LiAsF ₆ , the lithium salt shown in Chemical formula 15, the lithium salt shown in Chemical formula ₁₆ , and Chemical formula 17 It was found that it was preferable to use at least one member selected from the group consisting of the cyclic imide salt shown in FIG.

  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 1st secondary battery 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 4th secondary battery 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, 37 ... protective tape, 40 ... exterior member, 41 ... adhesion film.

Claims (18)

A scan sulfone compound, a solvent containing a cyclic carbonate derivative having halogen atoms is contained,
The sulfone compound includes at least one member selected from the group consisting of the compounds shown in Chemical Formulas 1 (1) to (8),
The cyclic carbonate derivative having a halogen atom includes the compound shown in Chemical Formula 2,
Secondary battery electrolyte.

(In the formula, R1, R10, R15 and R16 are —CH ₂ — or an alkylene group having 6 or less carbon atoms, or at least a part of hydrogen (H) of the group consisting of an allyl group, a vinylene group and an aryl group. R2, R3, R4, R5, R6, R7, R8, R9, R11, R12, R13, R14, R17, R18, R19, R20, R21, R22, R23, a group substituted by at least one of them. R24, R25, R26, R27, and R28 each represents an alkyl group, an allyl group, an aryl group, an aralkyl group, an alkoxyalkyl group, a group in which at least a part of these hydrogens is substituted with a halogen, a hydrogen group, or a halogen group. .)

(R51, R52, R53 and R54 are a methyl group, an ethyl group, or a group in which at least a part of hydrogen is substituted with fluorine (F), chlorine (Cl) or bromine (Br), hydrogen, or a fluorine group, or Represents a chlorine group or a bromine group, and at least one of R25, R26, R27 and R28 is a group having halogen.) The sulfone compound includes at least one of the compounds represented by chemical formulas 3 (1) to (54):
The cyclic carbonate derivative having a halogen atom includes at least one of the compounds shown in Chemical Formulas 4 (1) to (23).
The electrolyte for secondary batteries according to claim 1.

The content of the sulfone compound in the solvent is in the range of 0.01% by mass or more and 10% by mass or less .
The electrolyte for secondary batteries according to claim 1. The cyclic carbonate derivative having a halogen atom includes 4-fluoro-1,3-dioxolan-2-one ,
The electrolyte for secondary batteries according to claim 1. The solvent further includes a cyclic carbonate compound having an unsaturated bond ,
The electrolyte for secondary batteries according to claim 1. Of 5 light metal salt shown in, LiPF _6, LiClO _4, LiAsF _6, of 6 lithium salt shown in, of 7 lithium salt shown in, 8 indicated cyclic imide salt and of 9 in the indicated annular reduction Including at least one member of the group consisting of imide salts ,
The electrolyte for secondary batteries according to claim 1.

(R31 represents —C (═O) —R41—C (═O) — group (R41 represents an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group), or —C (═O). -C (R43) (R44)-group (R43, R44 represents an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group), or -C (= O) -C (= O)- R32 represents a halogen, an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group, X11 and X12 each represent oxygen (O) or sulfur, and M11 represents a transition metal element or a short group. Represents a group 3B element, a group 4B element or a group 5B element in the periodic table, and M21 represents a group 1A element, a group 2A element or aluminum in the short periodical table Represents (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-period type periodic table. R29 represents an alkylene group having 2 to 5 carbon atoms, or a group obtained by substituting at least a part of hydrogen with fluorine. t is 1, 2 or 3.)

(M2 represents a Group 1A element, Group 2A element or aluminum in the short-period type periodic table. R30 represents an alkylene group having 2 to 5 carbon atoms, or a group in which at least a part of hydrogen is substituted with fluorine. U is 1, 2 or 3.) Including the light metal salt shown in Chemical Formula 10 ,
The electrolyte for secondary batteries according to claim 1.

(R31 represents —C (═O) —R41—C (═O) — group (R41 represents an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group), or —C (═O). -C (R43) (R44)-group (R43, R44 represents an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group), or -C (= O) -C (= O)- R33 represents a halogen, 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 from 1 3 is an integer, b1 is 0, 2 or 4, and c, d, e and f are each an integer of 1 to 3.) Difluoro [oxolato-O, O ′] lithium borate shown in Chemical Formula 11 (1), tetrafluoro [oxolato-O, O ′] lithium phosphate shown in Chemical Formula 11 (2), shown in Chemical Formula 11 (3) difluoro bis [oxalate -O, O '] lithium phosphate, of 11 (4) to the indicated difluoro [3,3,3-trifluoro-2-oxide-2-trifluoromethyl propionitrile diisocyanatohexane (2 -) - O, O ′] lithium borate, bis [3,3,3-trifluoro-2-oxide-2-trifluoromethylpropionate (2-) — O, O ′] borane shown in Chemical Formula 11 And at least one selected from the group consisting of lithium bis [oxolato-O, O ′] lithium borate shown in Chemical Formula 11 (6) ,
The electrolyte for secondary batteries according to claim 1.

Used for lithium secondary battery,
The electrolyte for secondary batteries according to claim 1. An electrolyte is provided with a positive electrode and a negative electrode ,
The electrolyte contains a scan sulfone compound, a solvent containing a cyclic carbonate derivative having halogen atoms,
The sulfone compound includes at least one member selected from the group consisting of the compounds represented by chemical formulas 12 (1) to (8),
The cyclic carbonate derivative having a halogen atom includes the compound shown in Chemical formula 13,
Secondary battery.

(In the formula, R1, R10, R15 and R16 are —CH ₂ — or an alkylene group having 6 or less carbon atoms, or at least a part of hydrogen (H) of the group consisting of an allyl group, a vinylene group and an aryl group. R2, R3, R4, R5, R6, R7, R8, R9, R11, R12, R13, R14, R17, R18, R19, R20, R21, R22, R23, a group substituted by at least one of them. R24, R25, R26, R27, and R28 each represents an alkyl group, an allyl group, an aryl group, an aralkyl group, an alkoxyalkyl group, a group in which at least a part of these hydrogens is substituted with a halogen, a hydrogen group, or a halogen group. .)

(R51, R52, R53 and R54 are a methyl group, an ethyl group, or a group in which at least a part of hydrogen is substituted with fluorine (F), chlorine (Cl) or bromine (Br), hydrogen, or a fluorine group, or Represents a chlorine group or a bromine group, and at least one of R25, R26, R27 and R28 is a group having halogen.) The sulfone compound includes at least one of the compounds shown in Chemical formulas 14 (1) to (54),
The cyclic carbonate derivative having a halogen atom includes at least one of the compounds represented by Chemical formulas 15 (1) to (23).
The secondary battery according to claim 10.

The content of the sulfone compound in the solvent is in the range of 0.01% by mass or more and 10% by mass or less .
The secondary battery according to claim 10 . The cyclic carbonate derivative having a halogen atom includes 4-fluoro-1,3-dioxolan-2-one ,
The secondary battery according to claim 10 . The solvent further includes a cyclic carbonate compound having an unsaturated bond ,
The secondary battery according to claim 10 . The electrolyte includes a light metal salt shown in Chemical formula 16 , LiPF ₆ , LiClO ₄ , LiAsF ₆ , a lithium salt shown in Chemical formula 17 , a lithium salt shown in Chemical formula 18 , a cyclic imide salt shown in Chemical formula 19 and Chemical formula 20 Including at least one of the group consisting of the cyclic imide salts shown ,
The secondary battery according to claim 10 .

(R31 represents —C (═O) —R41—C (═O) — group (R41 represents an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group), or —C (═O). -C (R43) (R44)-group (R43, R44 represents an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group), or -C (= O) -C (= O)- R32 represents a halogen, an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group, X11 and X12 each represent oxygen (O) or sulfur, and M11 represents a transition metal element or a short group. Represents a group 3B element, a group 4B element or a group 5B element in the periodic table, and M21 represents a group 1A element, a group 2A element or aluminum in the short periodical table Represents (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-period type periodic table. R29 represents an alkylene group having 2 to 5 carbon atoms, or a group obtained by substituting at least a part of hydrogen with fluorine. t is 1, 2 or 3.)

(M2 represents a Group 1A element, Group 2A element or aluminum in the short-period type periodic table. R30 represents an alkylene group having 2 to 5 carbon atoms, or a group in which at least a part of hydrogen is substituted with fluorine. U is 1, 2 or 3.) The electrolyte includes a light metal salt shown in Chemical formula 21 ,
The secondary battery according to claim 10 .

(R31 represents —C (═O) —R41—C (═O) — group (R41 represents an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group), or —C (═O). -C (R43) (R44)-group (R43, R44 represents an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group), or -C (= O) -C (= O)- R33 represents a halogen, 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 from 1 3 is an integer, b1 is 0, 2 or 4, and c, d, e and f are each an integer of 1 to 3.) Difluoro [oxolato-O, O ′] lithium borate shown in Chemical Formula 22 (1), tetrafluoro [oxolato-O, O ′] lithium phosphate shown in Chemical Formula 22 (2), shown in Chemical Formula 22 (3) difluoro bis [oxalate -O, O '] lithium phosphate, of 22 (4) to the indicated difluoro [3,3,3-trifluoro-2-oxide-2-trifluoromethyl propionitrile diisocyanatohexane (2 -) - O, O ′] lithium borate, bis [3,3,3-trifluoro-2-oxide-2-trifluoromethylpropionate (2-)-O, O ′] borane shown in Chemical Formula 22 (5) And at least one selected from the group consisting of lithium bis [oxolato-O, O ′] lithium borate shown in Chemical Formula 22 (6) ,
The secondary battery according to claim 10 .

Lithium secondary battery,
The secondary battery according to claim 10.

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