Non-aqueous electrolyte and non-aqueous electrolyte battery

Abstract

The invention provides a non-aqueous electrolyte solution and a non-aqueous electrolyte solution battery which can exhibit excellent normal-temperature cycle characteristics and low-temperature input characteristics after a cycle test when made into a non-aqueous electrolyte solution battery. The nonaqueous electrolyte solution contains: (I) at least one compound selected from the group consisting of a monofluorophosphate, a difluorophosphate, a monofluorosulfonate, a salt represented by general formula (1) described in the description, and a salt represented by general formula (2) described in the description; (II) a solute; (III) a non-aqueous organic solvent; and (IV) a compound represented by general formula (3) described in the description. The non-aqueous electrolyte solution battery contains the non-aqueous electrolyte solution.

Description

Non-aqueous electrolyte and non-aqueous electrolyte batteries Technical Field

[0001] This invention relates to non-aqueous electrolytes and non-aqueous electrolyte batteries. Background Technology

[0002] In recent years, in addition to energy storage systems for small, high-energy-density applications in information-related and communication devices such as personal computers, camcorders, digital cameras, mobile phones, and smartphones, the demand for high-capacity, high-output, and high-energy-density batteries that can be used as auxiliary power sources for electric vehicles, hybrid vehicles, and fuel cell vehicles has expanded dramatically. Furthermore, the demand for batteries capable of long-term use is also increasing for large-scale, power storage systems. As alternatives to these various energy storage systems, non-aqueous electrolyte batteries, such as lithium-ion batteries, are being actively developed. Non-aqueous electrolyte batteries typically consist of a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte.

[0003] To date, research has focused on optimizing various battery components, primarily the active materials of the positive or negative electrode, as a means to improve the cycle characteristics, high-temperature storage characteristics, and durability of non-aqueous electrolyte batteries. Non-aqueous electrolyte technologies are no exception, with proposals to suppress degradation caused by the decomposition of the non-aqueous electrolyte on the surface of the active positive or negative electrode by adding various additives.

[0004] Patent document 1 describes an improvement in preservation characteristics by using a non-aqueous electrolyte containing lithium monofluorophosphate or lithium difluorophosphate.

[0005] Patent document 2 describes how using a non-aqueous electrolyte containing LiPF6 and fluorosulfonate as the main electrolyte and setting the ratio of the two within a specified range can improve the initial charge and discharge capacity, input and output characteristics, and impedance characteristics.

[0006] Patent document 3 discloses a non-aqueous electrolyte containing phosphorus and boron complexes, with lithium difluorooxalate borate as the main component. Patent document 4 discloses an electrolyte that, by simultaneously containing difluorooxalate phosphate and tetrafluorooxalate phosphate, can improve cycling characteristics, high-temperature storage characteristics, and low-temperature characteristics below 0°C.

[0007] Patent document 5 describes a non-aqueous electrolyte containing a silane compound with a specified structure and an imide salt with a fluorophosphoryl group and / or a fluorosulfonyl group having a specific structure. This electrolyte exhibits a high average discharge voltage below -30°C, excellent low-temperature output characteristics, and excellent cycle and storage characteristics at high temperatures above 50°C.

[0008] Patent document 6 describes a non-aqueous electrolyte containing an indicator salt and a phosphine oxide compound having PF bonds and / or P-NH2 bonds, which provides excellent combustion suppression for both the electrolyte and the battery.

[0009] Patent document 7 describes how a non-aqueous electrolyte containing a small amount of FSO2NH2 can function as a resistance-reducing agent in a battery.

[0010] Prior art documents: Patent document 1: Japanese Unexamined Patent Application Publication No. Hei 11-067270; Patent document 2: Japanese Unexamined Patent Application Publication No. 2013-152956; Patent document 3: Japanese Unexamined Patent Application Publication No. 2002-110235; Patent document 4: Japanese Unexamined Patent Application Publication No. 2011-222193; Patent document 5: Japanese Unexamined Patent Application Publication No. 2016-157679; Patent document 6: International Publication No. 2005 / 104289; Patent document 7: Japanese Unexamined Patent Application Publication No. 2020-087825. Summary of the Invention

[0011] (I) Technical Problem to be Solved However, the research results of the inventors of this application have determined that: if the non-aqueous electrolyte containing additives shown in Patent Documents 1-3 and 5-7 is used, there is still room for improvement in the cycling characteristics at room temperature. Furthermore, it has been determined that: when using the non-aqueous electrolyte containing additives shown in Patent Document 4, there is also room for improvement in the low-temperature input characteristics after the cycling test.

[0012] The present invention was made in view of the above circumstances, and its purpose is to provide a non-aqueous electrolyte and a non-aqueous electrolyte battery that exhibit excellent room temperature cycling characteristics and low temperature input characteristics after cycling tests when manufactured into a non-aqueous electrolyte battery.

[0013] (II) Technical Solution The inventors of this application conducted in-depth research to solve this problem and discovered that by including specific salts and fluorine-containing compounds with specific structures in the non-aqueous electrolyte battery containing non-aqueous organic solvents and solutes, the electrolyte exhibits excellent room-temperature cycling characteristics and low-temperature input characteristics after cycling tests when used in non-aqueous electrolyte batteries, thus completing this invention. Specifically, the above-mentioned technical problem can be solved through the following configuration.

[0014] [1] A non-aqueous electrolyte comprising: (I) at least one compound selected from the group consisting of monofluorophosphate, difluorophosphate, monofluorosulfonate, salts represented by the following general formula (1) and salts represented by the following general formula (2); (II) a solute; (III) a non-aqueous organic solvent; and (IV) a compound represented by the following general formula (3).

[0015] [Chemical Formula 1] In general formula (1), W 1 Represents boron, phosphorus, or silicon atoms, where n1 is 1-3, n2 is 0-4, and p is 0 or 1. R 11 This refers to an alkylene group having 1 to 10 carbon atoms, a haloalkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a haloarylene group having 6 to 20 carbon atoms (these groups optionally contain substituents or heteroatoms in their structure). Furthermore, when n1 is 2 or more, the n1 R groups present... 11 (Optional mutual bonding), R 12 Y represents a halogen atom. 1 and Y 2 Each can independently represent an oxygen atom or a sulfur atom, Y 3 Represents a carbon atom or a sulfur atom. Y 3 The carbon or sulfur atom represented has q oxo groups (=O) bonded to it. When Y 3 When Y is a carbon atom, q is 1; when Y is a carbon atom, q is 1. 3 When the atom is sulfur, q is 1 or 2. M a+ This represents an alkali metal cation, an alkaline earth metal cation, or an onium cation, where 'a' represents the valence of the corresponding cation. 'a' to 'd' are either 1 or 2 and satisfy a × b = c × d.

[0016] [Chemical Formula 2] In general formula (2), M n+ It can be an alkali metal cation, an alkaline earth metal cation, or an onium cation, where n represents an integer with the same valence as the corresponding cation. X is a sulfur atom or a phosphorus atom; when X is a sulfur atom, m is 2 and R does not exist. 4 When X is a phosphorus atom, m is 1, R 1 R 2 R 3 and R 4 Each of the following organic groups is independently composed of a fluorine atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkenoxy group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an alkenoxy group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, a cycloalkenoxy group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, wherein fluorine atoms, oxygen atoms, and unsaturated bonds are optionally present in these organic groups.

[0017] [Chemical Formula 3] In general formula (3), W is a phosphorus atom or a sulfur atom. When W is a phosphorus atom, y is 1, and when W is a sulfur atom, y is 2.

[0018] [2] According to the non-aqueous electrolyte of [1], the ratio of the content of (IV) to the total mass of (I) and (IV) is (IV) / {(I)+(IV)}, which is 0.00019 to 0.99.

[0019] [3] The non-aqueous electrolyte according to [1] or [2], wherein the salt represented by the general formula (1) is at least one selected from the group consisting of bis(oxalate)borate, difluoro(oxalate)borate, tri(oxalate) phosphate, difluoro(oxalate) phosphate and tetrafluoro(oxalate) phosphate.

[0020] [4] The non-aqueous electrolyte according to any one of [1] to [3], wherein the salt represented by the general formula (2) has at least one PF bond or SF bond.

[0021] [5] The non-aqueous electrolyte according to any one of [1] to [4], wherein the cation of the salt shown in (I) is lithium ion, sodium ion, potassium ion or tetraalkylammonium ion.

[0022] [6] The non-aqueous electrolyte according to any one of [1] to [5], wherein (II) is at least one selected from the group consisting of LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, LiC4F9SO3, LiN(SO2F)2, LiAlO2, LiAlCl4, LiCl and LiI, or at least one selected from the group consisting of NaPF6, NaBF4, NaSbF6, NaAsF6, NaClO4, NaCF3SO3, NaC4F9SO3, NaN(SO2F)2, NaAlO2, NaAlCl4, NaCl and NaI.

[0023] [7] The non-aqueous electrolyte according to any one of [1] to [6], wherein the (III) comprises at least one selected from the group consisting of cyclic esters, chain esters, cyclic ethers, chain ethers, sulfone compounds, sulfoxide compounds and ionic liquids.

[0024] [8] The non-aqueous electrolyte according to [7], wherein the cyclic ester comprises a cyclic carbonate.

[0025] [9] According to the non-aqueous electrolyte of [8], wherein the cyclic carbonate comprises at least one selected from the group consisting of ethylene carbonate and propylene carbonate.

[0026]

[10] According to the non-aqueous electrolyte of [7], wherein the chain ester comprises a chain carbonate.

[0027]

[11] According to the non-aqueous electrolyte of

[10] , wherein the chain carbonate comprises at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate and methyl propyl carbonate.

[0028]

[12] The non-aqueous electrolyte according to any one of [1] to

[11] , wherein the non-aqueous electrolyte further comprises a mixture selected from vinylene carbonate, fluorovinyl carbonate, nitrate, propylene-1,3-sulfonyl lactone, 1,3-propane sulfonyl lactone, 1,6-diisocyanohexane, dimethyl dicarbonate, ethynyl vinyl carbonate, trans-difluorovinyl carbonate, 1,3,2-dioxazothiophene-2,2-dioxide, 4-propyl-1,3,2-dioxazothiophene-2,2-dioxide, methane disulfonate, 1 At least one of the following: 2-ethanedisulfonic anhydride, methanesulfonic anhydride, methanesulfonyl chloride, 1,4-dioxane-2,6-dione, triargyl phosphate, tri(trimethylsilyl)boronic acid ester, (ethoxy)pentafluorocyclotriphosphazene, tetrafluoro(pyridinium carboxylate) phosphate, 1,3-dimethyl-1,3-divinyl-1,3-bis(1,1,1,3,3,3-hexafluoroisopropyl)disiloxane, N,N'-carbonylbis(N-methylaminosulfonyl fluoride), tetravinylsilane, trivinylmethylsilane, tert-butylbenzene, tert-amylbenzene, fluorobenzene, and cyclohexylbenzene.

[0029]

[13] A non-aqueous electrolyte battery, comprising at least a positive electrode, a negative electrode, a separator and any one of [1] to

[12] a non-aqueous electrolyte.

[0030] (III) Beneficial Effects According to the present invention, a non-aqueous electrolyte and a non-aqueous electrolyte battery can be provided that exhibit excellent room temperature cycling characteristics and low temperature input characteristics after cycling tests when the non-aqueous electrolyte battery is manufactured. Detailed Implementation

[0031] In this specification, "~" is used to encompass the values ​​described before and after it as lower and upper limits.

[0032] The present invention will now be described in detail, but the following description of the constituent elements is only an example of an embodiment of the present invention, and the present invention is not limited to these specific contents.

[0033] 1. Regarding the non-aqueous electrolyte, the non-aqueous electrolyte of the present invention comprises: (I) at least one compound selected from the group consisting of monofluorophosphate, difluorophosphate, monofluorosulfonate, salts represented by the above general formula (1) and salts represented by the above general formula (2); (II) a solute; (III) a non-aqueous organic solvent; and (IV) a compound represented by the following general formula (3).

[0034] If a non-aqueous electrolyte containing both component (I) and component (IV) is applied to a non-aqueous electrolyte battery (e.g., a lithium-ion battery or a sodium-ion battery), components (I) and (IV) will decompose at least on either the positive or negative electrode, forming a coating with good cation conductivity on the surface of at least either the positive or negative electrode. This coating is believed to inhibit direct contact between the non-aqueous organic solvent or solute and the electrode active material, thereby reducing the cation dissociation energy of the solute. The inventors of this invention presume that the results will exhibit excellent room-temperature cycling characteristics and low-temperature input characteristics after cycling tests in non-aqueous electrolyte batteries.

[0035] <Regarding (I) at least one compound selected from the group consisting of monofluorophosphate, difluorophosphate, monofluorosulfonate, salts represented by general formula (1) and salts represented by general formula (2)> The non-aqueous electrolyte of the present invention comprises at least one compound selected from the group consisting of monofluorophosphate, difluorophosphate, monofluorosulfonate, salts represented by the above general formula (1) and salts represented by the above general formula (2) as component (I).

[0036] (Monofluorophosphate, difluorophosphate, and monofluorosulfonate) are cations (M1) possessed by monofluorophosphate, difluorophosphate, and monofluorosulfonate, respectively. n+ Examples of cations include alkali metal cations, alkaline earth metal cations, and onium cations. The type of cation is not particularly limited, and various cations can be selected from the above, provided that the performance of the non-aqueous electrolyte and the non-aqueous electrolyte battery of the present invention is not impaired.

[0037] As M1 n+ Alkali metal cations that can be used to represent alkali metal cations include lithium ion, sodium ion, potassium ion, rubidium ion, cesium ion, etc.

[0038] As M1 n+ Examples of alkaline earth metal cations that can be used to represent alkaline earth metal cations include magnesium ions, calcium ions, and barium ions.

[0039] As M1 n+ Examples of onion cations that can be used to represent onion cations include tetraalkylammonium, tetraalkylphosphonium, and imidazolium derivatives.

[0040] n represents the valence of the corresponding cation, which can be 1 to 3, or 1 or 2.

[0041] In particular, from the perspective of playing a role in promoting ion conduction in non-aqueous electrolyte batteries, M1 n+ Preferably, the ions are lithium ions, sodium ions, potassium ions, tetramethylammonium ions, tetraethylammonium ions, tetraalkylammonium ions, tetrabutylphosphonium ions, etc. More preferably, lithium ions, sodium ions, potassium ions, or tetraalkylammonium ions.

[0042] Furthermore, when used in lithium-ion battery applications, M1 n+ Lithium-ion is preferred, and when used in sodium-ion battery applications, M1 n+ Sodium ions are preferred.

[0043] (The salt represented by general formula (1)) [Chemical formula 4] In general formula (1), W 1 Represents boron, phosphorus, or silicon atoms, where n1 is 1-3, n2 is 0-4, and p is 0 or 1. R 11 This refers to an alkylene group having 1 to 10 carbon atoms, a haloalkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a haloarylene group having 6 to 20 carbon atoms (these groups optionally contain substituents or heteroatoms in their structure). Furthermore, when n1 is 2 or more, the n1 R groups present... 11 (Optional mutual bonding), R 12 Y represents a halogen atom. 1 and Y 2 Each can independently represent an oxygen atom or a sulfur atom, Y 3 Represents a carbon atom or a sulfur atom. Y 3 The carbon or sulfur atom represented has q oxo groups (=O) bonded to it. When Y 3 When Y is a carbon atom, q is 1; when Y is a carbon atom, q is 1. 3 When the atom is sulfur, q is 1 or 2. M a+ This represents an alkali metal cation, an alkaline earth metal cation, or an onium cation, where 'a' represents the valence of the corresponding cation. 'a' to 'd' are either 1 or 2 and satisfy a × b = c × d.

[0044] W 1 It represents boron atoms, phosphorus atoms, or silicon atoms, preferably boron atoms or phosphorus atoms.

[0045] As R 11 The alkylene group referred to can be linear or branched. Examples of alkylene groups with 1 to 10 carbon atoms include methylene, ethylene, n-propylene, isopropylene, n-butylene, and n-hexylene.

[0046] As R 11The alkyl halide represented by the number of carbon atoms from 1 to 10 can be any group formed by replacing any hydrogen atom of the aforementioned alkyl halide with a halogen atom.

[0047] As R 11 The arylene groups representing 6 to 20 carbon atoms can include phenylene, naphthylene, etc.

[0048] As R 11 The halogenated aryl groups represented by the number of carbon atoms from 6 to 20 can be listed as groups formed by replacing any hydrogen atom of the aforementioned aryl group with a halogen atom.

[0049] As R 11 Preferably, methylene, ethylene, n-propylene, difluoromethylene, tetrafluoroethylene, hexafluoropropylene, and more preferably methylene.

[0050] As R 12 The halogen atom represented can be fluorine, chlorine, iodine, etc., with fluorine being preferred.

[0051] Y 1 and Y 2 Each can be represented independently as an oxygen atom or a sulfur atom, preferably both as oxygen atoms.

[0052] Y 3 It represents a carbon atom or a sulfur atom, preferably a carbon atom.

[0053] As M a+ The alkali metal cations, alkaline earth metal cations, and onium cations represented can be listed above as M1. n+ The specific examples and preferred examples of the alkali metal cations, alkaline earth metal cations and onium cations listed are the same as those described above.

[0054] Examples of compounds represented by general formula (1) include bis(oxalate) borate, difluoro(oxalate) borate, tri(oxalate) phosphate, difluoro(oxalate) phosphate, tetrafluoro(oxalate) phosphate, tri(oxalate) silicate, difluoro(oxalate) silicate, difluoromalonate borate, tetrafluoromalonate phosphate, difluorosulfonate borate, difluoromaleate borate, and difluorofumarate borate.

[0055] The salt represented by general formula (1) is preferably at least one selected from the group consisting of bis(oxalato)borate, difluoro(oxalato)borate, tri(oxalato) phosphate, difluoro(oxalato) phosphate and tetrafluoro(oxalato) phosphate, and more preferably at least one selected from the group consisting of lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tri(oxalato) phosphate, lithium difluoro(oxalato) phosphate and lithium tetrafluoro(oxalato) phosphate.

[0056] (The salt represented by general formula (2)) [Chemical formula 5] In general formula (2), M n+ It can be an alkali metal cation, an alkaline earth metal cation, or an onium cation, where n represents an integer with the same valence as the corresponding cation. X is a sulfur atom or a phosphorus atom; when X is a sulfur atom, m is 2 and R does not exist. 4 When X is a phosphorus atom, m is 1, R 1 R 2 R 3 and R 4 Each of the following organic groups is independently composed of a fluorine atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkenoxy group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an alkenoxy group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, a cycloalkenoxy group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, wherein fluorine atoms, oxygen atoms, and unsaturated bonds are optionally present in these organic groups.

[0057] In general formula (2), M n+ Compared with the above M1 n+ The meanings are the same, and the specific examples and preferred examples are also the same.

[0058] In general formula (2), R 1 ~R 4 Each of the following organic groups is independently composed of a fluorine atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkenoxy group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an alkenoxy group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, a cycloalkenoxy group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, wherein fluorine atoms, oxygen atoms, and unsaturated bonds are optionally present in these organic groups.

[0059] The above-mentioned organic groups may optionally contain substituents in their structure.

[0060] As R 1 ~R 4 The alkyl group represented can be straight-chain or branched, and examples include alkyl or fluorinated alkyl groups with 1 to 10 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, trifluoromethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, 2,2,3,3-tetrafluoropropyl and 1,1,1,3,3,3-hexafluoroisopropyl.

[0061] As R1 ~R 4 The alkoxy group represented can be linear or branched, and examples include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, tert-butoxy, pentoxy, trifluoromethoxy, 2,2-difluoroethoxy, 2,2,2-trifluoroethoxy, 2,2,3,3-tetrafluoropropoxy, 1,1,1-trifluoroisopropoxy, and 1,1,1,3,3,3-hexafluoroisopropoxy, which are alkoxy groups or fluorinated alkoxy groups with 1 to 10 carbon atoms.

[0062] As R 1 ~R 4 The alkenyl group represented can be linear or branched, and examples include vinyl, 1-propenyl, 2-propenyl, isopropenyl, 2-butenyl, 3-butenyl and 1,3-butadienyl alkenyl groups with 2 to 10 carbon atoms or fluorinated alkenyl groups.

[0063] As R 1 ~R 4 The olefinic group represented can be linear or branched. Examples include ethyleneoxy, 1-propenoxy, 2-propenoxy, isopropenoxy, 2-butenoxy, 3-butenoxy, and 1,3-butadieneoxy, which are olefinic groups or fluorinated olefinic groups with 2 to 10 carbon atoms.

[0064] As R 1 ~R 4 The alkynyl group can be linear or branched, such as ethynyl, 2-propynyl and 1,1-dimethyl-2-propynyl, which are alkynyl groups or fluorinated alkynyl groups with 2 to 10 carbon atoms.

[0065] As R 1 ~R 4 The alkynyloxy group represented can be straight-chain or branched. Examples include acetylyoxyloxy, 2-propynoxyloxy, and 1,1-dimethyl-2-propynoxyloxy, which are alkynyloxy groups with 2 to 10 carbon atoms or fluorinated alkynoxyloxy groups.

[0066] As R 1 ~R 4 The cycloalkyl group referred to may include, for example, cyclopentyl and cyclohexyl groups with 3 to 10 carbon atoms, or fluorinated cycloalkyl groups.

[0067] As R 1 ~R 4 The cycloalkoxy group represented may include, for example, cyclopentoxy and cyclohexyloxy, which have 3 to 10 carbon atoms or contain fluorine.

[0068] As R 1 ~R4 The cycloalkenyl groups represented include, for example, cyclopentenyl and cyclohexenyl, which are cycloalkenyl groups or fluorinated cycloalkenyl groups with 3 to 10 carbon atoms.

[0069] As R 1 ~R 4 The cycloalkenyloxy group represented may include, for example, cyclopentenyloxy and cyclohexenyloxy, which are cycloalkenyloxy groups with 3 to 10 carbon atoms or fluorinated cycloalkenyloxy groups.

[0070] As R 1 ~R 4 The aryl group represented can be, for example, aryl or fluorinated aryl groups with 6 to 10 carbon atoms, such as phenyl, tolyl, and xylyl.

[0071] As R 1 ~R 4 The aryloxy group represented may include, for example, phenoxy, tolyloxy, and xyloxy, which are aryloxy groups or fluorinated aryloxy groups with 6 to 10 carbon atoms.

[0072] Preferred R 1 ~R 4 At least one of them represents a fluorine atom. That is, the salt represented by the preferred general formula (2) has at least one PF bond or SF bond.

[0073] If R 1 ~R 4 Each alkyl group, individually composed of a fluorine atom or containing a fluorine atom, exhibits strong electron-withdrawing properties that increase the degree of ionic dissociation, thereby increasing the ionic conductivity in the solution or composition, and is therefore preferred. Furthermore, if R... 1 ~R 4 Each fluorine atom is independent, and the increased mobility due to the smaller size of the anions results in a very high ionic conductivity in the solution or composition, which is therefore more preferable.

[0074] Furthermore, if R 1 ~R 4 When the number of carbon atoms is 6 or less, it tends to have a relatively high ionic conductivity, so it is preferred, more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms. Specifically, trifluoromethyl, pentafluoroethyl, etc. can be listed, and trifluoromethyl with a small anion size is particularly preferred.

[0075] The following are specific examples of anionic structures of salts represented by general formula (2), but are not limited thereto.

[0076] [Chemical Formula 6] [Chemical Formula 7] The salt represented by general formula (2) is preferably at least one compound from the group consisting of (fluorosulfonyl)(difluorophosphoryl)imine salt and bis(difluorophosphoryl)imine salt, more preferably lithium (fluorosulfonyl)(difluorophosphoryl)imine or lithium bis(difluorophosphoryl)imine.

[0077] As shown in monofluorophosphate, difluorophosphate, monofluorosulfonate, the salt represented by the above general formula (1) and the salt represented by the above general formula (2), the cation of these salts, i.e. the cation of the salt shown in (I), is preferably lithium ion, sodium ion, potassium ion or tetraalkylammonium ion.

[0078] The non-aqueous electrolyte of the present invention can use a single compound as (I), or it can be used as (I) by mixing two or more compounds in any combination or ratio according to the application.

[0079] In the non-aqueous electrolyte of the present invention, the content of (I) relative to the total amount of non-aqueous electrolyte (also referred to as "concentration of (I)") can be 0.01% by mass or more and 10% by mass or less.

[0080] The lower limit of the concentration of (I) can be 0.08% by mass or more, or 0.1% by mass or more, or 0.15% by mass or more, or 0.3% by mass or more, or 0.45% by mass or more, or 0.5% by mass or more, or 0.7% by mass or more, or 0.8% by mass or more. The upper limit of the concentration of (I) can be 8% by mass or less, or 5% by mass or less, or 4% by mass or less, or 3% by mass or less, or 1.5% by mass or less.

[0081] <Regarding (II) solute> The (II) solute (also referred to as "(II)") contained in the non-aqueous electrolyte of the present invention will be described.

[0082] (II) The solute is not particularly limited, and may be at least one selected from the group consisting of LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, LiC4F9SO3, LiN(SO2F)2, LiAlO2, LiAlCl4, LiCl and LiI, or at least one selected from the group consisting of NaPF6, NaBF4, NaSbF6, NaAsF6, NaClO4, NaCF3SO3, NaC4F9SO3, NaN(SO2F)2, NaAlO2, NaAlCl4, NaCl and NaI.

[0083] The non-aqueous electrolyte of the present invention can use a single compound as (II), or it can be used as (II) by mixing two or more compounds in any combination or ratio according to the application.

[0084] There are no particular restrictions on the concentration of (II) relative to the total amount of non-aqueous electrolyte. For example, the lower limit of the concentration of (II) can be set to 0.5 mol / L or higher, or 0.7 mol / L or higher, or 0.9 mol / L or higher. In addition, the upper limit of the concentration of (II) can be set to 5 mol / L or lower, or 4 mol / L or lower, or 2 mol / L or lower.

[0085] There is no particular limitation on the liquid temperature when (II) is dissolved in (III) non-aqueous organic solvent; it can be -20 to 80°C or 0 to 60°C.

[0086] <Regarding (III) Non-aqueous organic solvents> The (III) non-aqueous organic solvents (also referred to as "(III)") contained in the non-aqueous electrolyte of the present invention will be described. There is no particular limitation on the type of (III) non-aqueous organic solvent, and any non-aqueous organic solvent can be used.

[0087] The following non-aqueous organic solvents can be listed as specific examples of (III) non-aqueous organic solvents.

[0088] In addition to cyclic carbonates such as propylene carbonate (hereinafter sometimes referred to as "PC"), ethylene carbonate (hereinafter sometimes referred to as "EC"), and butene carbonate, γ-butyrolactone and γ-valerolactone can also be listed as cyclic esters.

[0089] In addition to diethyl carbonate (hereinafter sometimes referred to as "DEC"), dimethyl carbonate (hereinafter sometimes referred to as "DMC"), methyl ethyl carbonate (hereinafter sometimes referred to as "EMC"), methyl propyl carbonate, methyl acetate, methyl propionate, ethyl propionate (hereinafter sometimes referred to as "EP"), etc., other chain esters include methyl acetate, methyl propionate, ethyl propionate, etc.

[0090] Examples of cyclic ethers include tetrahydrofuran, 2-methyltetrahydrofuran, and dioxane.

[0091] Examples of chain ethers include dimethoxyethane and diethyl ether.

[0092] In addition, examples include sulfone compounds such as dimethyl sulfoxide and sulfolane. Furthermore, ionic liquids can also be listed.

[0093] (III) The non-aqueous organic solvent may contain at least one selected from the group consisting of cyclic esters, chain esters, cyclic ethers, chain ethers, sulfone compounds, sulfoxide compounds and ionic liquids.

[0094] Cyclic esters may include cyclic carbonates, which may include at least one selected from the group consisting of ethylene carbonate and propylene carbonate.

[0095] The chain ester may include the chain carbonate, which may include at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate and methyl propyl carbonate.

[0096] The non-aqueous electrolyte of the present invention can use a single compound as (III), or it can be used as (III) by mixing two or more compounds in any combination or ratio according to the application.

[0097] The content of cyclic carbonates is not particularly limited and can be arbitrary as long as it does not significantly impair the effects of the present invention. When used alone, the content can be set to 3% by volume or more, more preferably 5% by volume or more, in a 100% by volume non-aqueous organic solvent. By setting it within this range, it is easy to avoid the decrease in conductivity caused by the decrease in the dielectric constant of the non-aqueous electrolyte, and it is easy to keep the high-current discharge characteristics, stability relative to the negative electrode, and cycle characteristics of the non-aqueous electrolyte battery within a good range. In addition, it is usually set to 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. By setting it within this range, it is easy to keep the viscosity of the non-aqueous electrolyte within a suitable range, it is easy to suppress the decrease in ionic conductivity, and thus it is easy to keep the load characteristics of the non-aqueous electrolyte battery within a good range.

[0098] Furthermore, cyclic carbonates can be used in any combination of two or more. One preferred combination is a combination of ethylene carbonate and propylene carbonate. In this case, the volume ratio of ethylene carbonate to propylene carbonate is preferably 99:1 to 40:60, and particularly preferably 95:5 to 50:50. Further, the amount of propylene carbonate in the total non-aqueous organic solvent is not particularly limited, and can be arbitrary as long as it does not significantly impair the effects of the present invention. It is typically set at 1% by volume or more, preferably 2% by volume or more, more preferably 3% by volume or more, and typically 30% by volume or less, preferably 25% by volume or less, more preferably 20% by volume or less. If propylene carbonate is included within this range, excellent low-temperature properties can be further achieved while maintaining the characteristics of the combination of ethylene carbonate and dialkyl carbonates, which is therefore preferred.

[0099] Chain esters can be used alone, or two or more can be used simultaneously in any combination and ratio.

[0100] The content of the chain ester is not particularly limited, but in 100% by volume of a non-aqueous organic solvent, it is typically set at 15% by volume or more, preferably 20% by volume or more, and more preferably 25% by volume or more. Furthermore, it is typically set at 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. By keeping the content of the chain ester within the above range, it is easy to keep the viscosity of the non-aqueous electrolyte within a suitable range, to easily suppress the decrease in ionic conductivity, and thus to easily keep the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte battery within a good range. Furthermore, it is easy to avoid the decrease in conductivity caused by the decrease in the dielectric constant of the non-aqueous electrolyte, and to easily keep the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte battery within a good range.

[0101] Furthermore, by combining ethylene carbonate in specific amounts relative to specific chain esters, battery performance can be significantly improved.

[0102] For example, when dimethyl carbonate and ethyl methyl carbonate are selected as specific chain esters, the content of ethylene carbonate is not particularly limited and can be arbitrary as long as it does not significantly impair the effect of the present invention. It is typically set at 5% by volume or more, preferably 10% by volume or more, and also typically 45% by volume or less, preferably 40% by volume or less. The content of dimethyl carbonate is typically set at 20% by volume or more, preferably 30% by volume or more, and also typically 50% by volume or less, preferably 45% by volume or less. The content of ethyl methyl carbonate is typically set at 20% by volume or more, preferably 30% by volume or more, and also can be set at 50% by volume or less, preferably 45% by volume or less. By keeping the content within the above ranges, the low-temperature precipitation temperature of the electrolyte can be reduced, while the viscosity of the non-aqueous electrolyte can be reduced, thereby increasing the ionic conductivity, achieving high input-output even at low temperatures.

[0103] The content of the chain ether is not particularly limited, and can be arbitrary as long as it does not significantly impair the effects of the present invention. In a 100% volume non-aqueous organic solvent, it is typically set to 1% by volume or more, preferably 2% by volume or more, more preferably 3% by volume or more. Furthermore, it is typically set to 30% by volume or less, preferably 25% by volume or less, more preferably 20% by volume or less. If the content of the chain ether is within the above range, for example in the case of a lithium-ion battery with lithium as the main cation, it is easy to ensure the increased lithium-ion dissociation degree of the chain ether and the increased ionic conductivity due to the decrease in viscosity. Furthermore, when the negative electrode active material is a carbonaceous material, the phenomenon of co-intercalation of the chain ether and lithium ions can be suppressed, thus making it easier to keep the input / output characteristics and charge / discharge rate characteristics within a suitable range.

[0104] The content of the sulfone compound is not particularly limited and can be arbitrary as long as it does not significantly impair the effects of the present invention. In a 100% volume non-aqueous organic solvent, it is typically set to 0.3% volume or more, preferably 0.5% volume or more, more preferably 1% volume or more. Furthermore, it is typically set to 40% volume or less, preferably 35% volume or less, more preferably 30% volume or less. If the content of the sulfone compound is within the above range, it is easy to obtain improved durability, such as cycling characteristics and storage characteristics. In addition, the viscosity of the non-aqueous electrolyte can be kept within a suitable range, thus preventing a decrease in conductivity and ensuring that the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte battery are within a suitable range.

[0105] <Regarding the compound represented by (IV) general formula (3)> The non-aqueous electrolyte of the present invention further contains the compound represented by (IV) general formula (3) (also referred to as "IV").

[0106] [Chemical Formula 8] In general formula (3), W is a phosphorus atom or a sulfur atom. When W is a phosphorus atom, y is 1, and when W is a sulfur atom, y is 2.

[0107] The non-aqueous electrolyte of the present invention can use a single compound as (IV), or it can be used as (IV) by mixing two or more compounds in any combination or ratio according to the application.

[0108] In the non-aqueous electrolyte of the present invention, the content of (IV) relative to the total amount of the non-aqueous electrolyte (also referred to as "concentration of (IV)") can be 0.001% by mass or more and 5% by mass or less. The lower limit of the concentration of (IV) can be 0.005% by mass or more, 0.01% by mass or more, 0.05% by mass or more, 0.08% by mass or more, or 0.1% by mass or more. The upper limit of the concentration of (IV) can be 3% by mass or less, 2% by mass or less, 1% by mass or less, or 0.8% by mass or less.

[0109] In the non-aqueous electrolyte of the present invention, the mass ratio of (IV) content to the total mass of (I) and (IV), (IV) / {(I) + (IV)}, is preferably 0.00019 to 0.99. The lower limit of this ratio can be 0.0002 or more, 0.0005 or more, 0.0010 or more, 0.0100 or more, or 0.0500 or more. The upper limit of this ratio can be 0.8, 0.6, 0.4, or 0.2.

[0110] <Regarding other possible components> The basic structure of the non-aqueous electrolyte of the present invention has been described above. However, without prejudice to the spirit of the invention, the non-aqueous electrolyte of the present invention may contain the components described below in any combination / ratio (hereinafter also referred to as "other possible components" or "other components"). As other components, for example, additives commonly used in the art may be added in any proportion.

[0111] Specific examples of other components include vinylene carbonate, fluoroethylene carbonate, nitrates, propenyl-1,3-sulfonyl lactone, 1,3-propane sulfonyl lactone, 1,6-diisocyanohexane, dimethyl dicarbonate, ethynyl ethylene carbonate, trans-difluoroethylene carbonate, 1,3,2-dioxazothiophene-2,2-dioxide, 4-propyl-1,3,2-dioxazothiophene-2,2-dioxide, methanedisulfonate, 1,2-ethanedisulfonic anhydride, methanesulfonic anhydride, and methanesulfonyl chloride. The formulation includes, preferably, 1,4-dioxane-2,6-dione, triargyl phosphate, tris(trimethylsilyl)borate, (ethoxy)pentafluorocyclotriphosphazene, tetrafluoro(pyridinium carboxylate) phosphate, 1,3-dimethyl-1,3-divinyl-1,3-bis(1,1,1,3,3,3-hexafluoroisopropyl)disiloxane, N,N'-carbonylbis(N-methylaminosulfonyl fluoride), tetravinylsilane, trivinylmethylsilane, tert-butylbenzene, tert-amylbenzene, fluorobenzene, and cyclohexylbenzene, and preferably contains at least one substance selected from the above.

[0112] By including the other components mentioned above in the non-aqueous electrolyte of the present invention, at least one of the following can be improved: overcharging prevention effect, negative electrode coating formation effect, and positive electrode protection effect.

[0113] When the non-aqueous electrolyte of the present invention contains other components, the content of the other components relative to the total amount of the non-aqueous electrolyte can be more than 0.01% by mass and less than 10% by mass.

[0114] In addition, among the other components mentioned above, the content of fluoroethylene carbonate may be 0.01% by mass or more and 55% by mass or less relative to the total amount of non-aqueous electrolyte.

[0115] The non-aqueous electrolyte of the present invention is suitable for non-aqueous electrolyte batteries (preferably non-aqueous electrolyte secondary batteries).

[0116] 2. Aqueous Electrolyte Battery The non-aqueous electrolyte battery of the present invention comprises at least the non-aqueous electrolyte, negative electrode, and positive electrode described above. Furthermore, it may also include a separator or casing, etc.

[0117] The non-aqueous electrolyte battery of the present invention preferably includes at least a positive electrode, a negative electrode, a separator, and the non-aqueous electrolyte of the present invention.

[0118] The non-aqueous electrolyte battery of the present invention is preferably a non-aqueous electrolyte secondary battery.

[0119] As a negative electrode, there are no particular limitations; materials in which alkali metal ions or alkaline earth metal ions, primarily lithium or sodium ions, can be reversibly inserted and extracted can be used.

[0120] For example, in the case of lithium-ion batteries where the cation is primarily lithium, the negative electrode active material constituting the negative electrode is a material capable of lithium-ion doping / dedoping. Examples include: carbon materials with a d-value of less than 0.340 nm for the (002) crystal plane in X-ray diffraction; carbon materials with a d-value greater than 0.340 nm for the (002) crystal plane in X-ray diffraction; oxides of one or more metals selected from Si, Sn, and Al; metals selected from Si, Sn, and Al, or alloys containing these metals, or alloys of these metals or alloys with lithium; and substances containing at least one of lithium titanium oxides. These negative electrode active materials can be used individually or in combination of two or more. Furthermore, lithium metal, metal nitrides, tin compounds, conductive polymers, etc., can be used.

[0121] For example, in the case of sodium-ion batteries where the cation is primarily sodium, the negative electrode active material can be sodium metal, alloys of sodium metal with other metals such as tin, intermetallic compounds of sodium metal with other metals, various carbon materials, primarily hard carbon, metal oxides such as titanium oxide, metal nitrides, elemental tin, tin compounds, activated carbon, conductive polymers, etc. In addition, phosphorus (elemental) materials such as red phosphorus and black phosphorus, phosphorus compounds such as Co-P, Cu-P, Sn-P, Ge-P, and Mo-P, antimony (elemental), and antimony compounds such as Sb / C and Bi-Sb can be used. These negative electrode active materials can be used individually or in combination.

[0122] As a positive electrode, there are no particular limitations; materials in which alkali metal ions or alkaline earth metal ions, primarily lithium or sodium ions, can be reversibly inserted and extracted can be used.

[0123] For example, when the cation is lithium, as the positive electrode material (positive electrode active material), lithium-containing transition metal composite oxides such as LiCoO2, LiNiO2, LiMnO2, and LiMn2O4 can be used; substances formed by mixing multiple transition metals such as Co, Mn, and Ni in these lithium-containing transition metal composite oxides; substances formed by replacing some of the transition metals in these lithium-containing transition metal composite oxides with other metals besides the transition metals; phosphoric acid compounds of transition metals such as LiFePO4, LiCoPO4, and LiMnPO4, which are called olivine; oxides such as TiO2, V2O5, and MoO3; sulfides such as TiS2 and FeS; or conductive polymers such as polyacetylene, poly(p-phenylene oxide), polyaniline, and polypyrrole; activated carbon; free radical-generating polymers; and carbon materials.

[0124] Specifically, Li[Ni] can be listed as an example. 1 / 3 Mn 1 / 3 Co 1 / 3 O2, Li[Ni 0.45 Mn 0.35 Co 0.2 O2, Li[Ni 0.5 Mn 0.3 Co 0.2 O2, Li[Ni 0.6 Mn 0.2 Co 0.2 O2 (hereinafter, sometimes referred to as "NCM622"), Li[Ni 0.8 Mn 0.1 Co 0.1 O2 (hereinafter, sometimes referred to as "NCM811"), Li[Ni 0.49 Mn 0.3 Co 0.2 Zr 0.01 O2, Li[Ni 0.49 Mn 0.3 Co 0.2 Mg 0.01 O2, LiNi 0.8 Co 0.2 O2, LiNi 0.85 Co 0.10 Al 0.05 O2, LiNi 0.87 Co 0.10 Al 0.03 O2, LiNi 0.90 Co 0.07 Al 0.03 O2, LiNi 0.6 Co 0.3 Al 0.1 O2, LiMn 1.5 Ni 0.5O4, etc.

[0125] For example, when the cation is sodium, NaCrO2 or NaFe can be used as the positive electrode material (positive electrode active material). 0.5 Co 0.5 O2, NaFe 0.4 Mn 0.3 Ni 0.3 O2, NaNi 0.5 Ti 0.3 Mn 0.2 O2, NaNi 1 / 3 Ti 1 / 3 Mn 1 / 3 O2, NaNi 0.33 Ti 0.33 Mn 0.16 Mg 0.17 O2, Na 2 / 3 Ni 1 / 3 Ti 1 / 6 Mn 1 / 2 O2, Na 2 / 3 Ni 1 / 3 Mn 2 / 3 Sodium-containing transition metal complex oxides such as O2; substances formed by mixing multiple transition metals such as Co, Mn, and Ni in these sodium-containing transition metal complex oxides; substances formed by replacing some of the transition metals in these sodium-containing transition metal complex oxides with other metals besides the transition metals; polyanionic compounds such as NaFePO4, NaVPO4F, Na3V2(PO4)3, and Na2Fe2(SO4)3; and compounds with the formula Na a M b [Fe(CN)6] c The terms refer to sodium salts of Prussian blue analogues (M = Cr, Mn, Fe, Co, Ni, Cu or Zn, 0≤a≤2, 0.5≤b≤1.5, 0.5≤c≤1.5), oxides such as TiO2, V2O5, and MoO3, sulfides such as TiS2 and FeS, or conductive polymers such as polyacetylene, poly(p-phenylene oxide), polyaniline, and polypyrrole, activated carbon, free radical-generating polymers, and carbon materials.

[0126] Acetylene black, Ketjen black, carbon fiber or graphite as conductive materials, and polytetrafluoroethylene, polyvinylidene fluoride or SBR resin as binders can be added to the positive or negative electrode materials. They can also be further used to form sheet-like electrode sheets.

[0127] As a diaphragm used to prevent contact between the positive and negative electrodes, nonwoven fabrics or porous sheets made of polypropylene, polyethylene, paper, or glass fiber can be used.

[0128] Electrochemical devices in shapes such as coin-shaped, cylindrical, square, or aluminum laminate can be assembled from the above elements.

[0129] In this specification, in the preparation of the non-aqueous electrolyte, by setting each component to an appropriate addition amount and using a balance of appropriate precision, the value of (IV) / {(I)+(IV)}, which is the mass ratio of the content of (IV) to the total amount of (I) and (IV), can be calculated to five decimal places.

[0130] The present invention will be specifically described below using examples, but the present invention is not limited to these examples.

[0131] [Preparation of Non-Aqueous Electrolyte] <Example 1-1> (Preparation of Non-Aqueous Electrolyte 1-1) A mixed solvent of EC:DMC:EMC = 3:3:4 (volume ratio) was used as the non-aqueous organic solvent. Lithium hexafluorophosphate (hereinafter also referred to as "LiPF6") was dissolved in this solvent as a solute to a concentration of 1.0 mol / L. Lithium difluorophosphate (hereinafter also referred to as "DFP") was dissolved as component (I) to a concentration of 1.0% by mass relative to the total amount of the non-aqueous electrolyte. FSO2NH2 was further dissolved as component (IV) to a concentration of 0.1% by mass relative to the total amount of the non-aqueous electrolyte, thereby preparing non-aqueous electrolyte 1-1. Furthermore, the above preparation was carried out while maintaining a liquid temperature of 25°C.

[0132] <Examples 1-2~1-18> (Preparation of Non-Aqueous Electrolytes 1-2~1-18) Non-aqueous electrolytes 1-2~1-18 were prepared by dissolving components using the same steps as those used in the preparation of non-aqueous electrolyte 1-1, except for changing the type and concentration of component (I) and the concentration of component (IV) as shown in Table 1. Additionally, "FS" represents lithium fluorosulfonate, "BOB" represents lithium bis(fluorosulfonyl)borate, "DFOB" represents lithium difluoro(fluorosulfonyl)borate, "DFBOP" represents lithium difluoro(bis(fluorosulfonyl)imide), "TFOP" represents lithium tetrafluoro(fluorosulfonyl)phosphate, "TOP" represents lithium tri(fluorosulfonyl)phosphate, "DFPFSI" represents lithium (difluorophosphoryl)(fluorosulfonyl)imide, and "DFPI" represents lithium bis(difluorophosphoryl)imide.

[0133] <Comparative Example 1-0-1> (Preparation of Comparative Non-Aqueous Electrolyte 1-0-1) Comparative non-aqueous electrolyte 1-0-1 was prepared by dissolving the electrolyte using the same steps as the preparation of non-aqueous electrolyte 1-1, except that no components (I) and (IV) were added.

[0134] <Comparative Example 1-0-2> (Preparation of Comparative Non-Aqueous Electrolyte 1-0-2) Comparative non-aqueous electrolyte 1-0-2 was prepared by dissolving the non-aqueous electrolyte 1-1 using the same steps as the preparation of non-aqueous electrolyte 1-1, except that no component (I) was added.

[0135] <Comparative Examples 1-1 to 1-20> (Preparation of Comparative Non-Aqueous Electrolytes 1-1 to 1-20) Comparative non-aqueous electrolytes 1-1 to 1-18 were prepared by dissolving the components using the same steps as in the preparation of non-aqueous electrolyte 1-1, except that the type and concentration of component (I) were changed as shown in Table 1 and component (IV) was not added.

[0136] In addition, except for changing the types and concentrations of components (I) and (IV) as shown in Table 1, comparative non-aqueous electrolytes 1-19 to 1-20 were prepared by dissolving them using the same steps as those used in the preparation of non-aqueous electrolyte 1-1.

[0137] <Examples 2-1 to 2-18> (Preparation of non-aqueous electrolytes 2-1 to 2-18) Except for changing the types and concentrations of components (I) and (IV) as shown in Table 2, non-aqueous electrolytes 2-1 to 2-18 were prepared by dissolving them using the same steps as those for preparing non-aqueous electrolyte 1-1.

[0138] <Comparative Example 1-0-3> (Preparation of Comparative Non-Aqueous Electrolyte 1-0-3) Comparative non-aqueous electrolyte 1-0-3 was prepared by dissolving F2PONH2 as component (IV) using the same steps as the preparation of comparative non-aqueous electrolyte 1-0-2.

[0139] <Comparative Examples 2-1 to 2-8> (Preparation of Comparative Non-Aqueous Electrolytes 2-1 to 2-8) Comparative non-aqueous electrolytes 2-1 to 2-8 were prepared by dissolving the components using the same steps as those used in the preparation of non-aqueous electrolyte 1-1, except that the type and concentration of component (I) were changed as shown in Table 2 and component (IV) was not added.

[0140] <Examples 3-1 to 3-18, Comparative Examples 3-0-1 to 3-20> to <Examples 4-1 to 4-18, Comparative Examples 4-1 to 4-8> EC, DMC, and EMC were used as non-aqueous organic solvents, and FEC was used as other components. They were mixed and dissolved in a volume ratio of EC:FEC:DMC:EMC=3:0.2:3:3.8. Then, LiPF6 and lithium bis(fluorosulfonyl)imide (hereinafter also referred to as "LiFSI") were dissolved as solutes and their concentrations were made to 1.0 mol / L and 0.1 mol / L, respectively. The types and concentrations of components (I) and (IV) were changed according to Tables 3 and 4. Otherwise, the electrolytes were dissolved in the same way as those described in Tables 1 and 2 to prepare the non-aqueous electrolytes and comparative non-aqueous electrolytes described in each table.

[0141] <Examples 5-1 to 5-17, Comparative Examples 5-0-1 to 5-19> to <Examples 6-1 to 6-17, Comparative Examples 6-1 to 6-8> EC, PC, and EMC were used as non-aqueous organic solvents, and FEC was used as other components. The components were mixed and dissolved in a volume ratio of EC:PC:FEC:EMC=2:1:0.2:6.8. Then, sodium hexafluorophosphate (hereinafter also referred to as "NaPF6") was dissolved as a solute and its concentration was 1.0 mol / L. The types and concentrations of components (I) and (IV) were changed as described in Tables 5 and 6. Otherwise, the electrolytes were dissolved in the same way as those described in Tables 1 and 2 to prepare the non-aqueous electrolytes and comparative non-aqueous electrolytes described in each table.

[0142] [Fabrication of Non-Aqueous Electrolyte Batteries] (Fabrication of NCM622 Cathode) To 90.0% by mass of LiNi 0.6 CO 0.2 Mn 0.2 O2 powder was mixed with 5.0% by mass of polyvinylidene fluoride (hereinafter referred to as "PVDF") as a binder and 5.0% by mass of acetylene black as a conductive material, and N-methyl-2-pyrrolidone (hereinafter referred to as "NMP") was further added to prepare a positive electrode paste. The paste was coated on both sides of aluminum foil (A1085), dried, pressurized, and then punched into 4cm×5cm pieces to obtain the NCM622 positive electrode for testing.

[0143] (Fabrication of NCM811 cathode) To 92.0% by mass of LiNi 0.8 Mn 0.1 CO 0.1O2 powder was mixed with 3.5% by mass of PVDF as a binder and 4.5% by mass of acetylene black as a conductive material, and NMP was further added to prepare a positive electrode paste. The paste was coated on both sides of aluminum foil (A1085), dried, pressurized, and then punched into 4cm×5cm pieces to obtain the NCM811 positive electrode for testing.

[0144] (Sodium-ion battery cathode: NaNi) 0.5 Ti 0.3 Mn 0.2 (Preparation of O2 cathode) 90.0% by mass of NaNi is used as the cathode active material. 0.5 Ti 0.3 Mn 0.2 O2 was mixed with 5.0% by mass of acetylene black as a conductive agent and 5.0% by mass of PVDF as a binder, and NMP was further added as a solvent to prepare a positive electrode paste. This paste was coated on both sides of an aluminum foil (A1085), dried, pressurized, and then die-cut into 4cm × 5cm pieces, thus obtaining the experimental NaNi. 0.5 Ti 0.3 Mn 0.2 O2 positive electrode.

[0145] (Preparation of Natural Graphite Anode) A negative electrode paste was prepared by mixing 92.0% by weight of natural graphite powder with 3.0% by weight of conductive material (manufactured by Denka Company Limited, HS-100), 2.0% by weight of carbon nanofibers (manufactured by Showa Denko KK, VGCF), 2.0% by weight of styrene-butadiene rubber (hereinafter sometimes referred to as "SBR"), 1.0% by weight of sodium carboxymethyl cellulose (hereinafter sometimes referred to as "CMC"), and water. The paste was coated onto copper foil, dried, pressurized, and then die-cut into 4.5cm × 5.5cm pieces to obtain the experimental natural graphite anode.

[0146] (Preparation of Silicon-Containing Graphite Anode) A negative electrode paste was prepared by mixing 7.0% by mass of nano-silicon, 3.0% by mass of conductive material (manufactured by Denka Company Limited, HS-100), 2.0% by mass of carbon nanofibers (manufactured by Showa Denko KK, VGCF), 2.0% by mass of SBR, 1.0% by mass of CMC, and water into 85.0% by mass of artificial graphite powder. This paste was coated onto copper foil, dried, pressurized, and then die-cut into 4.5cm × 5.5cm pieces, thus obtaining the experimental silicon-containing graphite anode.

[0147] (Preparation of Hard Carbon Anode) 90.0% by weight of hard carbon powder (manufactured by KUREHA CORPORATION, Carbotron P) was mixed with 10.0% by weight of PVDF as a binder, and NMP was further added as a solvent to prepare the anode paste. The paste was coated onto aluminum foil (A1085), dried, pressed, and then die-cut into 4.5cm × 5.5cm pieces to obtain the experimental hard carbon anode.

[0148] (Fabrication of Non-Aqueous Electrolyte Batteries) Under an argon atmosphere with a dew point below -50°C, the terminals were fused to the aforementioned NCM622 positive electrode. Two polyethylene separators (5cm × 6cm) were then used to clamp both sides of the positive electrode. Furthermore, two natural graphite negative electrodes with pre-fused terminals were used to clamp the outer sides, with the negative electrode active material side facing the positive electrode active material side. These were then placed into an aluminum-laminated bag with an opening on one side, and a non-aqueous electrolyte was vacuum-injected. The opening was then sealed using heat. This process produced the aluminum-laminated non-aqueous electrolyte batteries of the examples and comparative examples in Tables 1-2.

[0149] Furthermore, in the examples and comparative examples in Tables 3-4, NCM811 was used as the positive electrode and silicon-containing graphite was used as the negative electrode to fabricate non-aqueous electrolyte batteries in the same manner.

[0150] Furthermore, in the examples and comparative examples in Tables 5-6, NaNi was used. 0.5 Ti 0.3 Mn 0.2 Using O2 as the positive electrode and hard carbon as the negative electrode, a non-aqueous electrolyte battery (sodium-ion battery) is made in the same way.

[0151] [Evaluation] <Initial Charge-Discharge Test: Lithium-ion Battery> First, using the manufactured battery, the following conditions were applied during testing at an ambient temperature of 25°C. Specifically, as the initial charge-discharge test, the following charge-discharge cycle was repeated three times: constant current and constant voltage charging at 5mA with a charging upper limit voltage of 4.2V, followed by constant current discharging at 10mA until the discharge cutoff voltage reached 2.5V; then, constant current and constant voltage charging again at 10mA with a charging upper limit voltage of 4.2V, followed by constant current discharging at 10mA until the discharge cutoff voltage reached 2.5V. The discharge capacity of the third cycle was set as the initial discharge capacity.

[0152] <Initial Charge-Discharge Test: Sodium-ion Battery> First, using the manufactured battery, conduct testing under the following conditions at an ambient temperature of 25°C. Specifically, as the initial charge-discharge test, repeat the following charge-discharge cycle three times: constant current and constant voltage charging at 5mA with a charging upper limit voltage of 4.1V, followed by constant current discharging at 10mA until the discharge cutoff voltage reaches 1.5V; then, constant current and constant voltage charging again at 10mA with a charging upper limit voltage of 4.1V, followed by constant current discharging at 10mA until the discharge cutoff voltage reaches 1.5V. Set the discharge capacity of the third cycle as the initial discharge capacity.

[0153] <Cyclic Test (25°C): Lithium-ion Battery> The non-aqueous electrolyte battery that had completed the initial charge-discharge test was charged at 100mA with a charging upper limit voltage of 4.2V, and then discharged at 100mA with a constant current until the discharge cutoff voltage reached 2.5V. This charge-discharge cycle at 100mA under 25°C was repeated 1000 times. Then, constant current and constant voltage charging was performed at 10mA with a charging upper limit voltage of 4.2V, and then constant current discharging was performed at 10mA with a constant current until the discharge cutoff voltage reached 2.5V. The discharge capacity was set as the discharge capacity after the cyclic test.

[0154] <Cycling Test (25°C): Sodium-ion Battery> The evaluation is conducted in the same manner as for lithium-ion batteries, except that the upper limit of charging voltage is changed to 4.1V and the discharge cutoff voltage is changed to 1.5V.

[0155] <Capacity retention after cycle testing: Lithium-ion batteries> The capacity retention after cycle testing is calculated using the following formula. The larger the value, the better the cycle performance.

[0156] Capacity retention rate after cycle testing (%) = (Discharge capacity after cycle testing / Initial discharge capacity) × 100 <Capacity retention rate after cycle testing: Sodium-ion batteries> is evaluated in the same way as lithium-ion batteries. The larger this value, the better the cycle characteristics.

[0157] <Determination of Low-Temperature (-20℃) DC Internal Resistance after Cyclic Testing: Lithium-ion Batteries> Non-aqueous electrolyte batteries that underwent the above cyclic testing were charged at 10mA for 150 minutes at an ambient temperature of 25℃. After standing at -20℃ for 5 hours, they were charged at a constant current for 10 seconds at specified current values ​​(0.5mA, 1.0mA, 2.5mA, 5.0mA, 10.0mA). The voltage at the 10th second was measured, and the voltage was plotted against the current values. The least squares method was applied to each graph to obtain the fitted straight line. The slope of the fitted straight line was set as the low-temperature DC internal resistance after cyclic testing. The smaller this value, the better the low-temperature input characteristics after cyclic testing.

[0158] <Cryogenic DC Internal Resistance Measurement After Cyclic Testing: Sodium-ion Batteries> Evaluation was conducted in the same manner as for lithium-ion batteries. A smaller value indicates better low-temperature input characteristics after cyclic testing.

[0159] The evaluation results are shown in Tables 1-6 below. In the embodiments in Tables 1-6, relative values ​​for the cycle capacity retention rate and the low-temperature DC internal resistance after the cycle test are also shown when each comparative example using non-aqueous electrolysis with the same conditions except for the absence of component (IV) is set to 100.

[0160] [Table 1] [Table 2] [Table 3] [Table 4] [Table 5] [Table 6] [Table 7] [Table 8] [Table 9] [Table 10] [Table 11] [Table 12] [Table 13] [Table 14] [Table 15] [Table 16] [Table 17] [Table 18] [Table 19] [Table 20] [Table 21] [Table 22] [Table 23] [Table 24] In the comparison of non-aqueous electrolytes 1-19 in Table 1, the comparison of non-aqueous electrolytes 3-19 in Table 3, and the comparison of non-aqueous electrolytes 5-18 in Table 5, SO2CH3NH2 (methylsulfonamide) is not included in component (IV), but for convenience, it is recorded in the component (IV) column.

[0161] In the comparison of non-aqueous electrolytes 1-20 in Table 1 and the comparison of non-aqueous electrolytes 3-20 in Table 3, compound 1a (Li) represents the following compound. Furthermore, compound 1a (Li) is not included in component (I), but for convenience, it is listed in the component (I) column.

[0162] [Chemical Formula 9] Compound 1a (Li) was synthesized by the method described in International Publication No. 2021 / 015264

[0090] .

[0163] In the comparison of non-aqueous electrolytes 5-19 in Table 5, compound 1a (Na) represents the following compound. Furthermore, compound 1a (Na) is not included in ingredient (I), but for convenience, it is listed in the ingredient (I) column.

[0164] [Chemical Formula 10] Compound 1a (Na) was synthesized by the method described in International Publication No. 2021 / 015264

[0090] .

[0165] As shown in Tables 1-6, under identical conditions except for the presence or absence of component (IV), the non-aqueous electrolyte battery containing the non-aqueous electrolyte of the embodiments containing both components (I) and (IV) exhibits superior room temperature cycling characteristics and low-temperature input characteristics after cycling tests compared to the non-aqueous electrolyte battery of the comparative example containing component (I) but not component (IV). Furthermore, the room temperature cycling characteristics and low-temperature input characteristics after cycling tests of the comparative examples containing component (IV) but not component (I), and the comparative examples containing neither component (I) nor (IV) are inferior to those of the non-aqueous electrolyte batteries of the embodiments. Moreover, for the comparative examples using compound 1a(Li) or 1a(Na), which are not components (I), their room temperature cycling characteristics and low-temperature input characteristics after cycling tests are worse than those of the corresponding examples using compounds that are components (I). Furthermore, for the comparative example that used SO2CH3NH2, which is a comparative compound not belonging to component (IV), its room temperature cycling characteristics and low temperature input characteristics after cycling tests were worse than those of the corresponding examples that used compounds belonging to component (IV).

[0166] Industrial Applicability: According to the present invention, a non-aqueous electrolyte and a non-aqueous electrolyte battery can be provided that exhibit excellent room temperature cycling characteristics and low temperature input characteristics after cycling tests when manufactured into a non-aqueous electrolyte battery.

[0167] Although the invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

[0168] Furthermore, this application is based on Japanese Patent Application No. 2023-174648, filed on October 6, 2023, the contents of which are incorporated herein by reference.

Claims

1. A non-aqueous electrolyte comprising: (I) at least one compound selected from the group consisting of monofluorophosphate, difluorophosphate, monofluorosulfonate, salts represented by general formula (1) and salts represented by general formula (2); (II) a solute; (III) a non-aqueous organic solvent; and (IV) a compound represented by general formula (3), [Chemical Formula 1] In general formula (1), W 1 Represents boron, phosphorus, or silicon atoms, where n1 is 1-3, n2 is 0-4, and p is 0 or 1; R 11 This refers to alkylene groups having 1 to 10 carbon atoms, haloalkylene groups having 1 to 10 carbon atoms, arylene groups having 6 to 20 carbon atoms, or haloarylene groups having 6 to 20 carbon atoms, wherein... These groups may optionally contain substituents or heteroatoms in their structure; and when n1 is 2 or more, there are n1 R groups. 11 Optional mutual bonding; R 12 Y represents a halogen atom. 1 and Y 2 Each can independently represent an oxygen atom or a sulfur atom, Y 3 Y represents a carbon atom or a sulfur atom; 3 The carbon or sulfur atom represented has q oxo groups (=O) bonded to it; when Y 3 When Y is a carbon atom, q is 1; when Y is a carbon atom, q is 1. 3 When q is a sulfur atom, it is 1 or 2; M a+ This indicates an alkali metal cation, an alkaline earth metal cation, or an onium cation, where 'a' represents the valence of the corresponding cation; 'a' to 'd' are either 1 or 2 and satisfy a × b = c × d; [Chemical Formula 2] In general formula (2), M n+ X is an alkali metal cation, an alkaline earth metal cation, or an onium cation, where n represents an integer with the same valence as the corresponding cation; X is a sulfur atom or a phosphorus atom, and when X is a sulfur atom, m is 2 and R does not exist. 4 When X is a phosphorus atom, m is 1, R 1 R 2 R 3 and R 4 Each of the following organic groups independently comprises a fluorine atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkenoxy group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an alkynoxy group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, a cycloalkenoxy group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, wherein fluorine atoms, oxygen atoms, and unsaturated bonds are optionally present in these organic groups; [Chemical Formula 3] In general formula (3), W is a phosphorus atom or a sulfur atom. When W is a phosphorus atom, y is 1, and when W is a sulfur atom, y is 2.

2. The non-aqueous electrolyte according to claim 1, wherein, The mass ratio of the content of (IV) to the total mass of (I) and (IV), (IV) / {(I)+(IV)}, is 0.00019 to 0.

99.

3. The non-aqueous electrolyte according to claim 1, wherein, The salt represented by the general formula (1) is at least one selected from the group consisting of bis(oxalato)borate, difluoro(oxalato)borate, tri(oxalato) phosphate, difluoro(oxalato) phosphate and tetrafluoro(oxalato) phosphate.

4. The non-aqueous electrolyte according to claim 1, wherein, The salt represented by the general formula (2) has at least one PF bond or SF bond.

5. The non-aqueous electrolyte according to claim 1, wherein, The cation of the salt shown in (I) is lithium ion, sodium ion, potassium ion or tetraalkylammonium ion.

6. The non-aqueous electrolyte according to claim 1, wherein, The (II) is at least one selected from the group consisting of LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiCF3SO3, LiC4F9SO3, LiN(SO2F)2, LiAlO2, LiAlCl4, LiCl and LiI, or at least one selected from the group consisting of NaPF6, NaBF4, NaSbF6, NaAsF6, NaClO4, NaCF3SO3, NaC4F9SO3, NaN(SO2F)2, NaAlO2, NaAlCl4, NaCl and NaI.

7. The non-aqueous electrolyte according to claim 1, wherein, The (III) comprises at least one selected from the group consisting of cyclic esters, chain esters, cyclic ethers, chain ethers, sulfone compounds, sulfoxide compounds and ionic liquids.

8. The non-aqueous electrolyte according to claim 7, wherein, The cyclic ester comprises cyclic carbonates.

9. The non-aqueous electrolyte according to claim 8, wherein, The cyclic carbonate comprises at least one selected from the group consisting of ethylene carbonate and propylene carbonate.

10. The non-aqueous electrolyte according to claim 7, wherein, The chain ester comprises chain carbonates.

11. The non-aqueous electrolyte according to claim 10, wherein, The chain carbonate comprises at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, and methyl propyl carbonate.

12. The non-aqueous electrolyte according to claim 1, wherein, The non-aqueous electrolyte further contains a mixture selected from vinylene carbonate, fluoroethylene carbonate, nitrates, propylene-1,3-sulfonyl lactone, 1,3-propanesulfonyl lactone, 1,6-diisocyanohexane, dimethyl dicarbonate, ethynyl ethylene carbonate, trans-difluoroethylene carbonate, 1,3,2-dioxazothiophene-2,2-dioxide, 4-propyl-1,3,2-dioxazothiophene-2,2-dioxide, methanedisulfonate, 1,2-ethanedisulfonic anhydride, methanesulfonic anhydride, and so on. At least one of the following: sulfonyl chloride, 1,4-dioxane-2,6-dione, triargyl phosphate, tris(trimethylsilyl)borate, (ethoxy)pentafluorocyclotriphosphazene, tetrafluoro(pyridinium carboxylate) phosphate, 1,3-dimethyl-1,3-divinyl-1,3-bis(1,1,1,3,3,3-hexafluoroisopropyl)disiloxane, N,N'-carbonylbis(N-methylaminosulfonyl fluoride), tetravinylsilane, trivinylmethylsilane, tert-butylbenzene, tert-amylbenzene, fluorobenzene, and cyclohexylbenzene.

13. A non-aqueous electrolyte battery, comprising at least a positive electrode, a negative electrode, a separator, and the non-aqueous electrolyte as described in any one of claims 1 to 12.

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