Non-aqueous electrolyte and non-aqueous electrolyte battery

Abstract

The invention provides a non-aqueous electrolyte. The present invention relates to a liquid crystal composition containing (I) a solute, (II) a non-aqueous organic solvent, (III) a compound represented by general formula (1) described in the description, (IV) a compound represented by general formula (4) described in the description, and (V) at least one compound selected from the group consisting of a nitrate, a compound represented by general formula (2) described in the description, and a compound represented by general formula (3) described in the description, (V) / {(III) + (IV)}, which is the mass ratio of the amount of (V) to the total amount of (III) and (IV), is 0.0040 or more.

Description

Technical Field

[0001] This application 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 equipment 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 integrated 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 even in large-scale, power storage systems is increasing. As alternatives to these various energy storage systems, non-aqueous electrolyte batteries such as lithium-ion batteries, lithium-ion capacitors, and lithium-ion batteries are being actively developed.

[0003] Lithium-ion batteries mainly consist of a positive electrode, a non-aqueous electrolyte, and a negative electrode. The negative electrode in lithium-ion batteries can be made of known materials such as metallic lithium, metal compounds capable of lithium intercalation and deintercalation (e.g., elemental metals, oxides, and alloys with lithium), and carbon materials. Lithium-ion batteries using carbon materials such as coke, artificial graphite, and natural graphite are particularly widely used. For example, reports have shown that lithium-ion batteries using highly crystalline carbon materials such as natural or artificial graphite as the negative electrode material suffer from reduced cycle characteristics because the non-aqueous organic solvent in the non-aqueous electrolyte is reduced and decomposed on the negative electrode surface during charging. The resulting decomposition products and gases hinder the battery's inherent electrochemical reactions.

[0004] Furthermore, it is known that lithium secondary batteries using lithium metal or its alloys, silicon, tin, or other metal elements or oxides as anode materials are prone to reduction and decomposition of non-aqueous organic solvents during the cycling of lithium secondary batteries with high initial capacity, due to the progress of anode material micronization. As a result, compared with carbon anode materials, this leads to an increase in the initial irreversible capacity of the battery, resulting in a decrease in the charge-discharge efficiency of the first cycle, and a significant reduction in battery performance such as battery capacity or cycling characteristics.

[0005] During the first charging cycle, when lithium cations are inserted into the negative electrode, the negative electrode reacts with the lithium cations or with the electrolyte solvent, forming a coating on the surface of the negative electrode mainly composed of lithium oxide, lithium carbonate, or alkyl lithium carbonate. This coating on the electrode surface is called the solid electrolyte interface (SEI), which inhibits the reduction and decomposition of the solvent and suppresses the degradation of battery performance. Its properties have a significant impact on battery performance.

[0006] Thus, due to the accumulation of decomposition products of non-aqueous organic solvents or the generation of gases, and the adverse effects caused by the micronization of the negative electrode material, lithium cannot be smoothly inserted into and extracted from the negative electrode, resulting in problems such as a significant reduction in battery characteristics, including cycle life.

[0007] Furthermore, as positive electrodes, materials such as LiCoO2, LiMn2O4, LiNiO2, and LiFePO4 are known. For lithium-ion secondary batteries using these materials, it has been reported that under high temperatures during charging, some of the non-aqueous organic solvent in the non-aqueous electrolyte undergoes localized oxidative decomposition at the interface between the positive electrode material and the non-aqueous electrolyte. The resulting decomposition products or gases hinder the battery's inherent electrochemical reactions, consequently reducing battery performance, such as cycle characteristics. It is known that, similar to the negative electrode, a coating of oxidative decomposition products also forms on the surface of the positive electrode, which also inhibits the oxidative decomposition of the solvent and plays an important role in suppressing gas generation.

[0008] As mentioned above, typical lithium secondary batteries have the following causes: the decomposition products or gases produced when non-aqueous electrolytes decompose on the positive or negative electrode hinder the movement of lithium ions; the battery expands, thereby reducing battery performance.

[0009] To overcome these technical challenges and improve battery performance, particularly in terms of long-term durability and output characteristics, it is important to form a SEI that is highly ionicly conductive, low in electronically conductive, and stable over the long term. Extensive efforts are underway to actively form a good SEI by adding small amounts (typically between 0.01% and 10% by mass) of compounds known as additives to non-aqueous electrolytes.

[0010] For example, Patent Document 1 describes a method of improving high-temperature cycling characteristics or inhibiting the deterioration of high-temperature storage characteristics by combining specific sulfonylimide salts or phosphorimide salts with oxalic acid complexes.

[0011] Furthermore, Patent Document 2 describes how adding a specific fluorinated imide salt to the electrolyte can achieve a good balance between suppressing the increase in internal resistance at low temperatures and suppressing gas generation at high temperatures.

[0012] Furthermore, Patent Document 3 describes a method of combining fluorinated cyclic carbonate with lithium nitrate to form an SEI that provides durability for Si-based anodes and improves cycle characteristics.

[0013] Furthermore, Patent Document 4 discloses a method that reduces the HF content in a non-aqueous electrolyte when stored at 50°C by including 0.0005 to 2% of a phosphite-based compound by weight of the non-aqueous electrolyte in the non-aqueous electrolyte, while simultaneously stabilizing the color.

[0014] In addition, Patent Document 5 describes the addition of a carbodiimide compound to a non-aqueous electrolyte to capture moisture introduced by the non-aqueous electrolyte or battery components, thereby suppressing the generation of hydrogen fluoride due to battery degradation.

[0015] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2013-051122 Patent Document 2: International Publication No. 2017 / 111143 Patent Document 3: Japanese Patent Publication No. 2016-523429 Patent Document 4: Chinese Publication No. 1601799 Patent Document 5: Japanese Patent Application Publication No. 10-294129 Summary of the Invention

[0016] (a) Technical problems to be solved However, according to the research of the inventors of this application, when using non-aqueous electrolytes containing phosphorimide salts and oxalic acid complexes as described in Patent Documents 1-2, although battery performance (suppression of internal resistance rise, high-temperature cycling characteristics, and suppression of gas) is indeed improved, electrolyte discoloration sometimes occurs when the non-aqueous electrolyte is stored at room temperature (25°C).

[0017] Furthermore, no examples of the effect of lithium nitrate described in Patent Document 3 on improving the stability of the electrolyte have been reported.

[0018] Furthermore, it has been clarified that adding only the phosphite compounds described in Patent Document 4 within the concentration range described in Patent Document 4 cannot solve the aforementioned coloring problem.

[0019] Furthermore, although the carbodiimide compound described in Patent Document 5 improves the stability of the electrolyte, there are no examples of its simultaneous use with non-aqueous electrolytes containing phosphorimide salts and oxalic acid complexes.

[0020] The purpose of this invention is to provide a non-aqueous electrolyte and a non-aqueous electrolyte battery using the above-mentioned non-aqueous electrolyte. The non-aqueous electrolyte exhibits excellent battery performance when used to make a non-aqueous electrolyte battery and can suppress discoloration when stored at room temperature (25°C) for a long time.

[0021] (II) Technical Solution The present invention has conducted in-depth research to solve this problem, and has found that by incorporating at least one compound selected from specific phosphorus-containing compounds and carbodiimide compounds in a specific proportion into a non-aqueous electrolyte containing a solute, a non-aqueous organic solvent, a specific phosphorimide salt, and a specific boron-based, phosphorus-based, or silicon-based complex such as an oxalic acid complex, the aforementioned technical problem can be solved. Specifically, the above-mentioned technical problem can be solved through the following configuration. [1] A non-aqueous electrolyte containing: (I) Solute, (II) Non-aqueous organic solvents, (III) The compounds represented by the following general formula (1), (IV) Compounds represented by the following general formula (4), and, (V) At least one compound selected from the group consisting of nitrates, compounds represented by general formula (2) below, and compounds represented by general formula (3) below. Wherein, the mass ratio of (V) to the total mass of (III) and (IV), (V) / {(III)+(IV)}, is 0.0040 or more.

[0023] [Chemical Formula 1] In general formula (1), M a1＋ For alkali metal cations, alkaline earth metal cations, or onium cations, a1 represents an integer with the same valence as the corresponding cation. a1~d1 represent integers from 1 to 2, satisfying a1×b1=c1×d1. 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 4 Each of the following is an organic group independently selected from fluorine atom, oxygen atom, alkyl group having 1 to 10 carbon atoms, alkoxy group having 1 to 10 carbon atoms, alkenyl group having 2 to 10 carbon atoms, alkenyloxy group having 2 to 10 carbon atoms, alkynyl group having 2 to 10 carbon atoms, alkynyloxy group having 2 to 10 carbon atoms, cycloalkyl group having 3 to 10 carbon atoms, cycloalkoxy group having 3 to 10 carbon atoms, cycloalkenyl group having 3 to 10 carbon atoms, cycloalkenyloxy group having 3 to 10 carbon atoms, aryl group having 6 to 10 carbon atoms, and aryloxy group having 6 to 10 carbon atoms, wherein the organic group optionally contains fluorine atom, oxygen atom, and / or unsaturated bond. [Chemical Formula 2] In general formula (4), W represents a boron atom, a phosphorus atom, or a silicon atom, n1 is 1 or 2, n2 is 2 or 4, and e is 0 or 1. When e is 0, R does not exist. 41 R 41 Y recorded on both sides of the adjacent 3 It bonds directly to the carbonyl group. R 41 This refers to alkylene groups with 1 to 10 carbon atoms, haloalkylene groups with 1 to 10 carbon atoms, alkenyl groups with 2 to 10 carbon atoms, haloalkenyl groups with 2 to 10 carbon atoms, aryl groups with 6 to 20 carbon atoms, or haloaryl groups with 6 to 20 carbon atoms (these groups optionally contain heteroatoms in their structure). Furthermore, when n1 is 2 or more, the presence of n1 R... 41 (Optional mutual bonding), R 42 Y represents a halogen atom. 1 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 When Y3 is a carbon atom, f is 1; when Y3 is a sulfur atom, f is 1 or 2. 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.

[0024] [Chemical Formula 3] In general formula (2), p, q, and r each independently represent 0 or 1, and R 5 ~R 7 Each is independently a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms that are optionally partially or wholly substituted with fluorine, R 5 With R 6 R 5 With R 7 、or R 6 With R 7 They can be arbitrarily bonded together to form a ring structure. [Chemical Formula 4] In general formula (3), R 8 and R 9 Each group is independently a hydrocarbon group with 1 to 20 carbon atoms. [2] According to the non-aqueous electrolyte described in [1], the ratio of (V) / {(III)+(IV)} is 0.0100~1.5000. [3] According to the non-aqueous electrolyte described in [1] or [2], wherein R of the general formula (1) 1 ~R4 At least one of them is a fluorine atom. [4] The non-aqueous electrolyte according to any one of [1] to [3], wherein the compound represented by the general formula (1) is a bis(difluorophosphoryl)imide salt or a (fluorosulfonyl)(difluorophosphoryl)imide salt. [5] The non-aqueous electrolyte according to any one of [1] to [4], wherein the compound represented by the general formula (4) is an oxalate compound. [6] According to any one of [1] to [5], the non-aqueous electrolyte, wherein q, r and s of the general formula (2) are all 1, and R 5 ~R 7 All identical hydrocarbon groups having 1 to 20 carbon atoms that are partially or entirely substituted with fluorine. [7] According to any one of [1] to [6], the non-aqueous electrolyte, wherein R is the general formula (3) 8 R 9 The atom bonded to the nitrogen atom is a secondary carbon atom. [8] The non-aqueous electrolyte according to any one of [1] to [7], wherein the compound represented by the general formula (3) is at least one selected from the group consisting of N,N'-diisopropylcarbodiimide and N,N'-dicyclohexylcarbodiimide. [9] The non-aqueous electrolyte according to any one of [1] to [8], wherein the (V) contains nitrates, and the content of the nitrates is less than 1% by mass relative to the total amount of the non-aqueous electrolyte.

[10] The non-aqueous electrolyte according to any one of [1] to [9], wherein the non-aqueous electrolyte contains fluoroethylene carbonate.

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

[10] , wherein (I) is at least one selected from the group consisting of LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiN(FSO2)2, LiAlO2, LiAlCl4, LiCl and LiI.

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

[10] , wherein (I) is at least one selected from the group consisting of NaPF6, NaBF4, NaSbF6, NaAsF6, NaClO4, NaN(FSO2)2, NaAlO2, NaAlCl4, NaCl and NaI.

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

[12] , wherein (II) 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.

[14] According to the non-aqueous electrolyte described in

[13] , the cyclic ester comprises a cyclic carbonate.

[15] According to the non-aqueous electrolyte of

[14] , the cyclic carbonate comprises at least one selected from the group consisting of ethylene carbonate and propylene carbonate.

[16] According to the non-aqueous electrolyte described in

[13] , the chain ester comprises a chain carbonate.

[17] According to the non-aqueous electrolyte of

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

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

[17] further comprises a mixture selected from vinylene carbonate, difluorophosphate, fluorosulfonate, propylene-1,3-sulactone, 1,3-propanesulfonyl, 1,6-diisocyanohexane, ethynylvinyl carbonate, trans-difluorovinyl carbonate, 1,3,2-dioxazothiophene-2,2-dioxide, 4-propyl-1,3,2-dioxazothiophene-2,2-dioxide, methanedisulfonate, 1,2-ethanedisulfonic anhydride, methanesulfonate, etc. At least one of the following: acid anhydride, methanesulfonyl chloride, 1,4-dioxane-2,6-dione, triargyl phosphate, tri(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.

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

[18] .

[0042] (III) Beneficial Effects According to this application, a non-aqueous electrolyte and a non-aqueous electrolyte battery using the above-mentioned non-aqueous electrolyte can be provided. The non-aqueous electrolyte can exhibit excellent battery performance when it is used to make a non-aqueous electrolyte battery and can suppress discoloration during long-term storage at room temperature (25°C). Detailed Implementation

[0043] In this manual, "~" is used to indicate the lower and upper limits, including the values ​​listed before and after it.

[0044] The present application will now be described in detail. The description of the constituent elements described below is an example of the implementation of the present application and is not limited to these specific contents.

[0045] 1. Regarding non-aqueous electrolytes The non-aqueous electrolyte of this application contains: (I) a solute, (II) a non-aqueous organic solvent, (III) a compound represented by general formula (1) below, (IV) a compound represented by general formula (4) below, and (V) at least one compound selected from the group consisting of nitrates, compounds represented by general formula (2) below, and compounds represented by general formula (3) below, wherein the mass ratio of (V) to the total amount of (III) and (IV) is 0.0040 or more.

[0046] [Chemical Formula 5] In general formula (1), M a1＋ For alkali metal cations, alkaline earth metal cations, or onium cations, a1 represents an integer with the same valence as the corresponding cation. a1~d1 represent integers from 1 to 2, satisfying a1×b1=c1×d1. 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 4 Each of the organic groups is independently selected from fluorine atoms, oxygen atoms, alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkenoxy groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, alkynoxy groups having 2 to 10 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, cycloalkoxy groups having 3 to 10 carbon atoms, cycloalkenyl groups having 3 to 10 carbon atoms, cycloalkenyl groups having 3 to 10 carbon atoms, cycloalkenoxy groups having 3 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aryloxy groups having 6 to 10 carbon atoms, wherein the organic group optionally contains fluorine atoms, oxygen atoms, and / or unsaturated bonds.

[0047] [Chemical Formula 6] In general formula (4), W represents a boron atom, a phosphorus atom, or a silicon atom, n1 is 1 or 2, n2 is 2 or 4, and e is 0 or 1. When e is 0, R does not exist. 41 R 41 Y recorded on both sides of the adjacent3 It bonds directly to the carbonyl group. R 41 This refers to alkylene groups with 1 to 10 carbon atoms, haloalkylene groups with 1 to 10 carbon atoms, alkenyl groups with 2 to 10 carbon atoms, haloalkenyl groups with 2 to 10 carbon atoms, aryl groups with 6 to 20 carbon atoms, or haloaryl groups with 6 to 20 carbon atoms (these groups optionally contain heteroatoms in their structure). Furthermore, when n1 is 2 or more, the presence of n1 R... 41 (Optional mutual bonding), R 42 Y represents a halogen atom. 1 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 When Y3 is a carbon atom, f is 1; when Y3 is a sulfur atom, f is 1 or 2. 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.

[0048] [Chemical Formula 7] In general formula (2), p, q, and r each independently represent 0 or 1, and R 5 ~R 7 Each is independently a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms that are optionally partially or wholly substituted with fluorine, R 5 With R 6 R 5 With R 7 、or R 6 With R 7 They can be arbitrarily bonded together to form a ring structure.

[0049] [Chemical Formula 8] In general formula (3), R 8 and R 9 Each is an independent hydrocarbon group with 1 to 20 carbon atoms.

[0050] The non-aqueous electrolyte of this application, by including (III) and (IV), exhibits excellent battery performance when manufactured into a non-aqueous electrolyte battery. Furthermore, by further adding (V) such that the mass ratio of (V) to the combined mass of (III) and (IV) is 0.0040 or higher, excellent battery performance can be maintained, while coloring can be suppressed during long-term storage at room temperature (25°C).

[0051] The following is a detailed description of each ingredient.

[0052] <Regarding (I) solute> The (I) solute (also referred to as "(I)") contained in the non-aqueous electrolyte of this application will be described.

[0053] (I) The solute is not particularly limited, for example it can be at least one of the following groups: LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiN(FSO2)2, LiAlO2, LiAlCl4, LiCl and LiI, or at least one of the following groups: NaPF6, NaBF4, NaSbF6, NaAsF6, NaClO4, NaN(FSO2)2, NaAlO2, NaAlCl4, NaCl and NaI.

[0054] The non-aqueous electrolyte of this application 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.

[0055] There is no particular limitation on the concentration of (I) relative to the total amount of non-aqueous electrolyte. For example, the lower limit of the concentration of (I) can be 0.5 mol / L or more, or 0.7 mol / L or more, or 0.9 mol / L or more. Furthermore, the upper limit of the concentration of (I) can be 5 mol / L or less, or 4 mol / L or less, or 2 mol / L or less. In addition, when two or more types of (I) are used, it is preferable that the total concentration of these solutes is within the range described above.

[0056] There is no particular limitation on the liquid temperature when (I) is dissolved in (II) non-aqueous organic solvent; it can be -20~80℃ or 0~60℃.

[0057] Furthermore, when used in lithium-ion batteries, the cation of the solute is more preferably lithium-ion, and when used in sodium-ion batteries, the cation of the solute is more preferably sodium-ion.

[0058] <Regarding (II) Non-aqueous organic solvents> The non-aqueous organic solvent (also referred to as "(II)") contained in the non-aqueous electrolyte of this application will be described. There is no particular limitation on the type of non-aqueous organic solvent (II), and any non-aqueous organic solvent can be used.

[0059] As specific examples of (II) non-aqueous organic solvents, the following non-aqueous organic solvents can be listed.

[0060] In addition to cyclic carbonates such as propylene carbonate (hereinafter sometimes referred to as "PC"), ethylene carbonate (hereinafter sometimes referred to as "EC"), fluoroethylene carbonate (hereinafter sometimes referred to as "FEC"), and butenyl carbonate, γ-butyrolactone and γ-valerolactone can also be listed as cyclic esters. Furthermore, for the aforementioned FEC, when its content is 10% by mass or less relative to the total amount of the non-aqueous electrolyte, it is defined as other additives as described later.

[0061] 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.

[0062] Examples of cyclic ethers include tetrahydrofuran, 2-methyltetrahydrofuran, and dioxane.

[0063] Examples of chain ethers include dimethoxyethane and diethyl ether.

[0064] In addition, examples include sulfone compounds such as dimethyl sulfoxide and sulfolane. Furthermore, ionic liquids can also be listed.

[0065] (II) 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.

[0066] Cyclic esters include cyclic carbonates, which may include at least one selected from the group consisting of ethylene carbonate, propylene carbonate and fluoroethylene carbonate, or at least one selected from the group consisting of ethylene carbonate and propylene carbonate.

[0067] The chain ester includes 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.

[0068] The non-aqueous electrolyte of this application 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.

[0069] The content of cyclic carbonates is not particularly limited and can be arbitrary as long as it does not significantly impair the effect of this application. When used alone, the content can be 3% by volume or more, or 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 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.

[0070] 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. In addition, there is no particular limitation on the amount of propylene carbonate in the total amount of non-aqueous organic solvent, and it can be arbitrary as long as it does not significantly impair the effect of this application. It is usually 1% by volume or more, preferably 2% by volume or more, more preferably 3% by volume or more, and usually 30% by volume or less, preferably 25% by volume or less, more preferably 20% by volume or less. If propylene carbonate is included in this range, the low-temperature characteristics can be further improved while maintaining the characteristics of the combination of ethylene carbonate and dialkyl carbonate, which is therefore preferred.

[0071] Chain esters can be used alone, or two or more can be used simultaneously in any combination and ratio.

[0072] The content of the chain ester is not particularly limited, but in a 100% volume non-aqueous organic solvent, it is typically 15% by volume or more, preferably 20% by volume or more, and more preferably 25% by volume or more. Furthermore, it is typically 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.

[0073] Furthermore, by combining ethylene carbonate in specific amounts relative to specific chain esters, battery performance can be significantly improved.

[0074] 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 this application. It is typically 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 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 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. By keeping the content within the above ranges, it is possible to reduce the low-temperature precipitation temperature of the electrolyte while also reducing the viscosity of the non-aqueous electrolyte and increasing the ionic conductivity, thus achieving high input-output even at low temperatures.

[0075] The content of the chain ether is not particularly limited, and can be arbitrary as long as it does not significantly impair the effect of this application. In 100% by volume of a non-aqueous organic solvent, it is generally 1% by volume or more, preferably 2% by volume or more, more preferably 3% by volume or more, and generally 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, it is easy to ensure the effect of improving the lithium-ion dissociation degree of the chain ether and the improvement of ionic conductivity caused by the decrease in viscosity. In addition, 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 enabling the input-output characteristics and charge-discharge rate characteristics to be within a suitable range.

[0076] The content of the sulfone compound is not particularly limited, and can be arbitrary as long as it does not significantly impair the effect of this application. In 100% by volume of a non-aqueous organic solvent, it is generally 0.3% by volume or more, preferably 0.5% by volume or more, more preferably 1% by volume or more, and generally 40% by volume or less, preferably 35% by volume or less, more preferably 30% by volume or less. If the content of the sulfone compound is within the above range, it is easy to obtain the effect of improved durability such as cycle characteristics and storage characteristics. In addition, the viscosity of the non-aqueous electrolyte can be kept within a suitable range, the decrease in conductivity can be avoided, and the input-output characteristics and charge-discharge rate characteristics of the non-aqueous electrolyte battery can be kept within a suitable range.

[0077] <(III) Compounds represented by general formula (1)> The non-aqueous electrolyte contained in this application is described in terms of (III) the compound represented by the following general formula (1) (also referred to as "III")

[0078] [Chemical Formula 9] In general formula (1), M a1＋For alkali metal cations, alkaline earth metal cations, or onium cations, a1 represents an integer with the same valence as the corresponding cation. a1~d1 represent integers from 1 to 2, satisfying a1×b1=c1×d1. 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 4 Each of the organic groups is independently selected from fluorine atoms, oxygen atoms, alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkenoxy groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, alkynoxy groups having 2 to 10 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, cycloalkoxy groups having 3 to 10 carbon atoms, cycloalkenyl groups having 3 to 10 carbon atoms, cycloalkenyl groups having 3 to 10 carbon atoms, cycloalkenoxy groups having 3 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aryloxy groups having 6 to 10 carbon atoms, wherein the organic group optionally contains fluorine atoms, oxygen atoms, and / or unsaturated bonds.

[0079] In general formula (1), R 1 ~R 4 Each of the organic groups is independently selected from fluorine atoms, oxygen atoms, alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkenoxy groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, alkynoxy groups having 2 to 10 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, cycloalkoxy groups having 3 to 10 carbon atoms, cycloalkenyl groups having 3 to 10 carbon atoms, cycloalkenyl groups having 3 to 10 carbon atoms, cycloalkenoxy groups having 3 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aryloxy groups having 6 to 10 carbon atoms, wherein the organic group optionally contains fluorine atoms, oxygen atoms, and / or unsaturated bonds.

[0080] The aforementioned organic groups may contain substituents in their structure.

[0081] As R 1 ~R 4 The alkyl group represented can be linear or branched, and examples include 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.

[0082] As R 1 ~R 4The alkoxy group represented can be linear or branched. 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 with 1 to 10 carbon atoms or fluorinated alkoxy groups with 1 to 10 carbon atoms.

[0083] 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.

[0084] As R 1 ~R 4 The olefinic group represented can be linear or branched. Examples include vinyloxy, 1-propenyloxy, 2-propenyloxy, isopropenyloxy, 2-butenyloxy, 3-butenyloxy, and 1,3-butadienyloxy, which are olefinic groups or fluorinated olefinic groups with 2 to 10 carbon atoms.

[0085] 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.

[0086] As R 1 ~R 4 The alkynyloxy group represented can be straight-chain or branched. Examples include alkynyloxy, 2-propynyloxy, and 1,1-dimethyl-2-propynyloxy, which are alkynyloxy groups with 2 to 10 carbon atoms or fluorinated alkynyloxy groups.

[0087] 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.

[0088] As R 1 ~R 4 The cycloalkoxy group represented may include, for example, cyclopentyloxy and cyclohexyloxy, which are cycloalkoxy groups with 3 to 10 carbon atoms or fluorinated cycloalkoxy groups.

[0089] As R 1 ~R 4The cycloalkenyl groups represented include, for example, cyclopentenyl and cyclohexenyl, which are cycloalkenyl groups or fluorinated cycloalkenyl groups with 3 to 10 carbon atoms.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] If R 1 ~R 4 Individually composed of fluorine atoms or alkoxy groups containing fluorine atoms, the increased degree of ionic dissociation due to their strong electron-withdrawing properties leads to higher ionic conductivity in the non-aqueous electrolyte, thus making them preferred. Furthermore, if the anion is fluorine, the increased mobility due to the smaller anion size results in extremely high ionic conductivity in the non-aqueous electrolyte, making them even more preferred. Preferred R 1 ~R 4 At least one of them is a fluorine atom.

[0094] In addition, R 1 ~R 4 The number of carbon atoms is preferably 6 or less. If the number of carbon atoms is 6 or less, there is a tendency for the aforementioned ionic conductivity to be relatively high, which is therefore preferred.

[0095] In general formula (1), M a1＋ This refers to alkali metal cations, alkaline earth metal cations, or onium cations. There are no particular limitations on the type of cation, provided it does not impair the performance of the non-aqueous electrolyte and the non-aqueous electrolyte battery of this application; a wide variety of substances can be selected from the above.

[0096] As M a1＋ Examples of alkali metal cations that can be represented include lithium ions, sodium ions, potassium ions, rubidium ions, and cesium ions.

[0097] As M a1＋ Examples of alkaline earth metal cations include magnesium ions, calcium ions, and barium ions.

[0098] As M a1＋Examples of onion cations that can be represented include tetraalkylammonium, tetraalkylphosphonium, and imidazolium derivatives.

[0099] a1 represents the valence of the corresponding cation, which can be 1 or 2.

[0100] In particular, from the perspective of playing a role in promoting ion conduction in non-aqueous electrolyte batteries, M a1＋ Preferably, lithium ions, sodium ions, potassium ions, tetramethylammonium ions, tetraethylammonium ions, tetrabutylphosphonium ions, etc.

[0101] Furthermore, when used in lithium-ion battery applications, M a1＋ Lithium-ion is preferred, and when used in sodium-ion battery applications, M a1＋ Sodium ions are preferred.

[0102] The compound represented by the above general formula (1) is preferably any one of the compounds represented by the following general formulas (1-1) to (1-5).

[0103] [Chemical Formula 10] In general formulas (1-1) to (1-5), M a1＋ It can be an alkali metal cation, an alkaline earth metal cation, or an onium cation, where a1 represents an integer with the same valence as the corresponding cation. a1~d1 represent integers from 1 to 2, and in general formulas (1-1)~(1-2), a1=d1 is satisfied, and in general formulas (1-3)~(1-5), a1×b1=2×d1 is satisfied.

[0104] R 11 ~R 16 and R 18 ~R 23 Each of the organic groups is independently selected from fluorine atoms, alkoxy groups having 1 to 10 carbon atoms, alkenoxy groups having 2 to 10 carbon atoms, alkynoxy groups having 2 to 10 carbon atoms, cycloalkoxy groups having 3 to 10 carbon atoms, cycloalkenoxy groups having 3 to 10 carbon atoms, and aryloxy groups having 6 to 10 carbon atoms, wherein the organic group may also optionally contain fluorine atoms, oxygen atoms, and / or unsaturated bonds.

[0105] R 17 and R 24The organic group is selected from fluorine atoms, alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkenoxy groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, alkynoxy groups having 2 to 10 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, cycloalkoxy groups having 3 to 10 carbon atoms, cycloalkenyl groups having 3 to 10 carbon atoms, cycloalkenoxy groups having 3 to 10 carbon atoms, cycloalkenoxy groups having 3 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aryloxy groups having 6 to 10 carbon atoms, wherein the organic group may optionally contain fluorine atoms, oxygen atoms, and / or unsaturated bonds.

[0106] M in general formulas (1-1)~(1-5) a1+ With M in general formula (1) a1+ The meanings are the same, and the preferred examples are also the same.

[0107] R in general formulas (1-1)~(1-5) 11 ~R 16 and R 18 ~R 23 The following are examples of alkoxy groups with 1 to 10 carbon atoms, alkenoxy groups with 2 to 10 carbon atoms, alkynoxy groups with 2 to 10 carbon atoms, cycloalkoxy groups with 3 to 10 carbon atoms, cycloalkenoxy groups with 3 to 10 carbon atoms, and aryloxy groups with 6 to 10 carbon atoms, which are listed above as R in general formula (1). 1 ~R 4 And groups that are the same as the listed groups.

[0108] R 11 ~R 16 and R 18 ~R 23 Each is preferably a fluorine atom or an alkoxy group having a fluorine atom, more preferably a fluorine atom. Furthermore, R 11 ~R 16 and R 18 ~R 23 The number of carbon atoms is preferably 6 or less.

[0109] R in general formulas (1-2) and (1-5) 17 and R 24 Alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkenyloxy groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, alkynyloxy groups having 2 to 10 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, cycloalkoxy groups having 3 to 10 carbon atoms, cycloalkenyl groups having 3 to 10 carbon atoms, cycloalkenyloxy groups having 3 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aryloxy groups having 6 to 10 carbon atoms, can be listed as R in general formula (1). 1 ~R4 And groups that are the same as the listed groups.

[0110] R 17 and R 24 Preferably, it contains fluorine atoms. Furthermore, R... 17 and R 24 The number of carbon atoms is preferably 6 or less.

[0111] The compound represented by general formula (1) is preferably the compound represented by general formula (1-1) or (1-2) above, and more preferably bis(difluorophosphoryl)imide salt or (fluorosulfonyl)(difluorophosphoryl)imide salt.

[0112] The following are specific examples of anionic structures of compounds represented by general formula (1), but are not limited thereto.

[0113] [Chemical Formula 11] [Chemical Formula 12] [Chemical Formula 13] [Chemical Formula 14] [Chemical Formula 15] The non-aqueous electrolyte of this application 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.

[0114] In the non-aqueous electrolyte of this application, the content of (III) (also referred to as "concentration of (III)") relative to the total amount of the non-aqueous electrolyte can be 0.01% by mass or more and 10% by mass or less. The lower limit of the concentration of (III) can be 0.05% by mass or more, 0.1% by mass or more, or 0.5% by mass or more. The upper limit of the concentration of (III) can be 5% by mass or less, 3.5% by mass or less, or 2.5% by mass or less.

[0115] <(IV) Compounds represented by general formula (4)> The compounds represented by general formula (4) (also referred to as "(IV)") contained in the non-aqueous electrolyte of this application are described.

[0116] [Chemical Formula 16] In general formula (4), W represents a boron atom, a phosphorus atom, or a silicon atom, n1 is 1 or 2, n2 is 2 or 4, and e is 0 or 1. When e is 0, R does not exist. 41 R 41 Y recorded on both sides of the adjacent 3 It bonds directly to the carbonyl group. R 41 This refers to alkylene groups with 1 to 10 carbon atoms, haloalkylene groups with 1 to 10 carbon atoms, alkenyl groups with 2 to 10 carbon atoms, haloalkenyl groups with 2 to 10 carbon atoms, aryl groups with 6 to 20 carbon atoms, or haloaryl groups with 6 to 20 carbon atoms (these groups optionally contain heteroatoms in their structure). Furthermore, when n1 is 2 or more, the presence of n1 R... 41 (Optional mutual bonding), R 42 Y represents a halogen atom. 1 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 When Y3 is a carbon atom, f is 1; when Y3 is a sulfur atom, f is 1 or 2. 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.

[0117] In general formula (4), W represents a boron atom, a phosphorus atom or a silicon atom, preferably a boron atom or a phosphorus atom.

[0118] R 41 This refers to alkylene groups with 1 to 10 carbon atoms, haloalkylene groups with 1 to 10 carbon atoms, alkenyl groups with 2 to 10 carbon atoms, haloalkenyl groups with 2 to 10 carbon atoms, aryl groups with 6 to 20 carbon atoms, or haloaryl groups with 6 to 20 carbon atoms. These groups may contain substituents or heteroatoms in their structure. Furthermore, when n1 is 2 or more, there are n1 R groups. 41 They can bond with each other.

[0119] As R 41 The alkylene groups referred to include, for example, methylene, ethylene, propylene, isopropylene, butylene, isobutylene, and pentylene, which have 1 to 10 carbon atoms.

[0120] As R 41 The alkyl halide represented can be, for example, difluoromethylene, 2,2-difluoroethylene, 2,2,3,3-tetrafluoropropylene, etc., which have 1 to 10 carbon atoms.

[0121] As R 41The alkenyl groups represented include, for example, vinylene, 1-propenylene, 2-propenylene, isopropenylene, 2-butenylene, 3-butenylene, and 1,3-butadiene, which are alkenyl groups with 2 to 10 carbon atoms.

[0122] As R 41 The haloene groups represented include, for example, difluorovinylene groups with 2 to 10 carbon atoms.

[0123] As R 41 The arylene groups represented include, for example, phenylene, tolyl, and xylene, which have 6 to 20 carbon atoms.

[0124] As R 41 The halogenated aryl groups represented include, for example, fluorophenylene and other halogenated aryl groups with 6 to 20 carbon atoms.

[0125] As R 41 Preferably, it is an alkylene group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, more preferably a methylene or vinylene group.

[0126] As R 42 The halogen atoms represented can include fluorine, chlorine, and bromine atoms, among others.

[0127] R 42 The preferred atom is fluorine.

[0128] Y 1 Y 2 Each can be represented independently as an oxygen atom or a sulfur atom, preferably both as oxygen atoms.

[0129] Y 3 It represents a carbon atom or a sulfur atom, preferably a carbon atom.

[0130] As M a＋ The alkali metal cations, alkaline earth metal cations, and onium cations represented can be listed as M in the above general formula (1). a1＋ The preferred examples of the alkali metal cations, alkaline earth metal cations, and onium cations listed are also the same.

[0131] In addition, when used in lithium-ion battery applications, M a＋ More preferably lithium-ion, and when used in sodium-ion battery applications, M a＋ Sodium ions are preferred.

[0132] The compound represented by the above general formula (4) is preferably an oxalate compound. That is, it is preferably a compound represented by the following general formula (4-1).

[0133] [Chemical Formula 17] In general formula (4-1), W, n1, n2, and R 42 M a＋ and a~d and W, n1, n2, R in the above general formula (4) 42 M a＋ The meanings of a~d are the same, and the preferred examples are also the same.

[0134] Examples of compounds represented by the above general formula (4) include difluorooxalate borate, bis(oxalate borate), tetrafluorooxalate phosphate, difluorobis(oxalate) phosphate, tri(oxalate) phosphate, difluorobis(oxalate) silicate, tetrafluoro(malonic acid) phosphate, difluoro(sulfoacetic acid) borate, difluoro(maleic acid) borate, and difluoro(fumaric acid) borate. Preferably, from the perspective of solubility in the electrolyte or thermal stability at high temperatures, at least one salt selected from the group consisting of difluorooxalate borate, bis(oxalate borate), tetrafluorooxalate phosphate, difluorobis(oxalate) phosphate, and tri(oxalate) phosphate is preferred.

[0135] The non-aqueous electrolyte of this application can use a single compound as (IV), or two or more compounds can be mixed in any combination or ratio as (IV) depending on the application.

[0136] In the non-aqueous electrolyte of this application, the content of (IV) (also referred to as "concentration of (IV)") relative to the total amount of the non-aqueous electrolyte can be 0.01% by mass or more and 10% by mass or less. The lower limit of the concentration of (IV) can be 0.05% by mass or more, 0.1% by mass or more, or 0.5% by mass or more. The upper limit of the concentration of (IV) can be 5% by mass or less, 3.5% by mass or less, or 2.5% by mass or less.

[0137] <(V) is selected from at least one compound in the group consisting of nitrates, compounds represented by general formula (2), and compounds represented by general formula (3).> The non-aqueous electrolyte of this application contains at least one compound selected from the group consisting of nitrates, compounds represented by the following general formula (2), and compounds represented by the following general formula (3) (also referred to as "(V)").

[0138] (nitrates) Examples of nitrates include alkali metal nitrates such as lithium ion, sodium ion, potassium ion, rubidium ion, and cesium ion, as well as alkaline earth metal nitrates such as magnesium ion, calcium ion, and barium ion.

[0139] Furthermore, when used in lithium-ion batteries, lithium nitrate is more preferred, and when used in sodium-ion batteries, sodium nitrate is more preferred.

[0140] (The compound represented by general formula (2)) [Chemical Formula 18] In general formula (2), p, q, and r each independently represent 0 or 1, and R 5 ~R 7 Each is independently a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms that are optionally partially or wholly substituted with fluorine, R 5 With R 6 R 5 With R 7 、or R 6 With R 7 They can be arbitrarily bonded together to form a ring structure.

[0141] In general formula (2), p, q and r each independently represent 0 or 1, preferably all of them represent 1.

[0142] R 5 ~R 7 Each can independently represent a fluorine atom, or a hydrocarbon group consisting of 1 to 20 carbon atoms that are optionally substituted with fluorine, either partially or entirely.

[0143] As R 5 ~R 7 The hydrocarbon groups represented by carbon atoms of 1 to 20 can include alkyl groups of 1 to 20 carbon atoms, alkenyl groups of 2 to 20 carbon atoms, alkynyl groups of 2 to 20 carbon atoms, cycloalkyl groups of 3 to 20 carbon atoms, cycloalkenyl groups of 3 to 20 carbon atoms, and aryl groups of 6 to 20 carbon atoms.

[0144] The hydrocarbon groups with 1 to 20 carbon atoms mentioned above may contain substituents in their structure.

[0145] As R 5 ~R 7 The alkyl group represented can be straight-chain or branched, and examples include alkyl or fluorinated alkyl groups with 1 to 20 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.

[0146] As R 5 ~R 7 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 20 carbon atoms or fluorinated alkenyl groups.

[0147] As R5 ~R 7 The alkynyl group can be linear or branched. Examples include ethynyl, 2-propynyl, and 1,1-dimethyl-2-propynyl, which are alkynyl groups or fluorinated alkynyl groups with 2 to 20 carbon atoms.

[0148] As R 5 ~R 7 The cycloalkyl group referred to may include, for example, cyclopentyl and cyclohexyl groups with 3 to 20 carbon atoms, or fluorinated cycloalkyl groups.

[0149] As R 5 ~R 7 The cycloalkenyl groups represented include, for example, cyclopentenyl and cyclohexenyl, which are cycloalkenyl groups or fluorinated cycloalkenyl groups with 3 to 20 carbon atoms.

[0150] As R 5 ~R 7 The aryl group represented can be, for example, aryl or fluorinated aryl groups with 6 to 20 carbon atoms, such as phenyl, tolyl, and xylyl.

[0151] From the perspective of color suppression effect, R is preferred. 5 R 6 and R 7 Each of the components is independently an alkyl group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms; more preferably, it is methyl, ethyl, isopropyl, 1,1,1,3,3,3-hexafluoroisopropyl, or phenyl; even more preferably, it is ethyl, isopropyl, 1,1,1,3,3,3-hexafluoroisopropyl, or phenyl; particularly preferably, it is isopropyl, 1,1,1,3,3,3-hexafluoroisopropyl, or phenyl; and most preferably, it is phenyl.

[0152] For the compound represented by the above general formula (2), preferably: q, r and s are all 1, and R 5 ~R 7 All identical hydrocarbon groups having 1 to 20 carbon atoms that are partially or entirely substituted with fluorine.

[0153] That is, the compound represented by general formula (2) is preferably the compound represented by the following general formula (2-1).

[0154] [Chemical Formula 19] R in general formula (2-1) 5a ~R 7a All identical hydrocarbon groups having 1 to 20 carbon atoms that are partially or entirely substituted with fluorine.

[0155] As R 5a ~R7a The hydrocarbon groups represented by 1 to 20 carbon atoms that are substituted with fluorine, either partially or entirely, can be listed as R in the above general formula (2). 5 ~R 7 The hydrocarbon groups represented are optionally partially or wholly substituted with fluorine, and the number of carbon atoms is 1 to 20. The preferred examples are also the same.

[0156] The following shows compounds represented by general formula (2), but are not limited thereto.

[0157] [Chemical Formula 20] (The compound represented by general formula (3)) [Chemical Formula 21] In general formula (3), R 8 and R 9 Each is an independent hydrocarbon group with 1 to 20 carbon atoms.

[0158] As R 8 and R 9 The hydrocarbon groups represented by carbon atoms of 1 to 20 can include alkyl groups of 1 to 20 carbon atoms, alkenyl groups of 2 to 20 carbon atoms, alkynyl groups of 2 to 20 carbon atoms, cycloalkyl groups of 3 to 20 carbon atoms, cycloalkenyl groups of 3 to 20 carbon atoms, and aryl groups of 6 to 20 carbon atoms.

[0159] The hydrocarbon groups with 1 to 20 carbon atoms mentioned above may contain substituents in their structure.

[0160] As R 8 and R 9 The alkyl groups with 1 to 20 carbon atoms, alkenyl groups with 2 to 20 carbon atoms, alkynyl groups with 2 to 20 carbon atoms, cycloalkyl groups with 3 to 20 carbon atoms, cycloalkenyl groups with 3 to 20 carbon atoms, and aryl groups with 6 to 20 carbon atoms represented by the above general formula (2) can be listed as R. 5 ~R 7 The above-mentioned groups.

[0161] Preferred R 8 and R 9 Each of the components is independently an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 3 to 20 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 5 to 6 carbon atoms, and even more preferably methyl, ethyl, isopropyl or cyclohexyl.

[0162] In addition, R 8 and R 9 It can represent hydrocarbon groups with the same number of carbon atoms from 1 to 20.

[0163] For R 8 and R 9 From the perspective of color suppression effect, it is further preferred that the atom bonded to the nitrogen atom in the general formula (3) is a secondary carbon atom, R 8 and R 9 Particularly preferred are either isopropyl or cyclohexyl. That is, the compound represented by general formula (3) is particularly preferred to be at least one selected from the group consisting of N,N'-diisopropylcarbodiimide and N,N'-dicyclohexylcarbodiimide.

[0164] The following shows compounds represented by general formula (3), but are not limited thereto.

[0165] [Chemical Formula 22] For (V), from the perspective of color inhibition effect, it is preferably at least one compound selected from the group consisting of nitrate and the compound represented by the above general formula (2), and more preferably the compound represented by the above general formula (2).

[0166] The non-aqueous electrolyte of this application can use a single compound as (V), or it can be used as (V) by mixing two or more compounds in any combination or ratio according to the application.

[0167] In the non-aqueous electrolyte of this application, the content of (V) (also referred to as the concentration of (V)) relative to the total amount of the non-aqueous electrolyte can be 0.005% by mass or more and 10% by mass or less. The lower limit of the concentration of (V) can be 0.008% by mass or more, 0.03% by mass or more, or 0.04% by mass or more. The upper limit of the concentration of (V) can be 5% by mass or less, 3% by mass or less, or 2% by mass or less.

[0168] In addition, when (V) contains nitrates, from the perspective of solubility in the non-aqueous electrolyte, the nitrate content is preferably 1% by mass or less relative to the total amount of the non-aqueous electrolyte.

[0169] In the non-aqueous electrolyte of this application, the mass ratio of (V) to the total mass of (III) and (IV), (V) / {(III) + (IV)}, is 0.0040 or higher. By making the above ratio 0.0040 or higher, a non-aqueous electrolyte that maintains excellent battery performance when manufactured as a non-aqueous electrolyte battery, while suppressing discoloration during long-term storage at room temperature (25°C), can be obtained. If the above ratio is less than 0.0040, the discoloration suppression effect will not be fully realized.

[0170] From the perspective of improving the color suppression effect, the above ratio is preferably 0.0100 or more, more preferably 0.0500 or more, even more preferably 0.1000 or more, and particularly preferably 0.2500 or more. Furthermore, there is no particular limitation on the upper limit of the above ratio, but from the perspective of the efficiency of color suppression brought about by adding (V), it is preferably 1.5000 or less. That is, (V) / {(III)+(IV)} is preferably 0.0100 to 1.5000.

[0171] <Regarding other additives> The non-aqueous electrolyte of this application is composed of the above-mentioned components as basic components. Other additives commonly used in the art can be added to the non-aqueous electrolyte of this application in any proportion, provided that the spirit of this disclosure is not impaired.

[0172] When the non-aqueous electrolyte of this application contains other additives, the content of the additives may be more than 0.01% by mass and less than 10% by mass relative to the total amount of the non-aqueous electrolyte.

[0173] Other additives include, for example, cyclohexylbenzene, cyclohexylfluorobenzene, biphenyl, 2-fluorobiphenyl, tert-butylbenzene, tert-amylbenzene, 2-fluorotoluene, fluorobenzene, vinylene carbonate (sometimes referred to as "VC"), oligomers of vinylene carbonate (with a number average molecular weight of 170-5000 converted from polystyrene), vinyl ethylene carbonate, difluoroanisole, fluoroethylene carbonate (sometimes referred to as "FEC"), 1,6-diisocyanohexane, ethynyl ethylene carbonate, trans-difluoroethylene carbonate, methylpropynyl carbonate, ethylpropynyl carbonate, etc. Dipropynyl carbonate, maleic anhydride, succinic anhydride, 1,3-propanesulfonyl lactone, propenyl-1,3-sulfonyl lactone, butanesulfonyl lactone, dimethyl vinylene carbonate, 1,3,2-dioxazothiophene-2,2-dioxide, 4-propyl-1,3,2-dioxazothiophene-2,2-dioxide, methanedisulfonate methylene, methanedisulfonate dimethyl ester, methanedisulfonate trimethyl ester, methanesulfonyl chloride, vinylsulfonyl fluoride, phenyl difluorophosphate, 1,2-ethanedisulfonic anhydride, trivinylmethylsilane, trivinylfluorosilane, tetravinylsilane, tri(trimethyl) Silicon-based borate esters, succinate, (ethoxy)pentafluorocyclotriphosphazene, tetrafluoro(pyridinecarboxylate) phosphate, difluoro(pyridinecarboxylate) borate ester, 1,3-dimethyl-1,3-divinyl-1,3-di(1,1,1,3,3,3-hexafluoroisopropyl)disiloxane, lithium fluorosulfonate, sodium fluorosulfonate, lithium trifluoromethanesulfonate, sodium trifluoromethanesulfonate, lithium nonafluorobutanesulfonate, sodium nonafluorobutanesulfonate, lithium monofluorophosphate, sodium monofluorophosphate, lithium bis(trifluoromethanesulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, lithium bis(pentafluoroethanesulfonyl)imide, bis(pentafluoroethanesulfonyl)imide Sodium imide, lithium (trifluoromethanesulfonyl)(pentafluoroethanesulfonyl)imide, sodium (trifluoromethanesulfonyl)(pentafluoroethanesulfonyl)imide, lithium (trifluoromethanesulfonyl)(fluorosulfonyl)imide, sodium (trifluoromethanesulfonyl)(fluorosulfonyl)imide, lithium (pentafluoroethanesulfonyl)(fluorosulfonyl)imide, sodium (pentafluoroethanesulfonyl)(fluorosulfonyl)imide, tri(trifluoromethanesulfonyl)methyllithium, tri(trifluoromethanesulfonyl)methylsodium, lithium acrylate, sodium acrylate, lithium methacrylate, sodium methacrylate and other carboxylates, lithium methyl sulfate, sodium methyl sulfate, lithium ethyl sulfate, sodium ethyl sulfate and other sulfate esters, etc.

[0174] In compositions containing fluoroethylene carbonate but not containing (V) as described above, there is a tendency to suppress coloring, but in compositions containing fluoroethylene carbonate and also containing (V) as described above, the coloring is easily suppressed.

[0175] In addition, as other additives, it is also preferable to contain, for example, a selection from vinylene carbonate, difluorophosphate, fluorosulfonate, propylene-1,3-sulactone, 1,3-propanesulfonyl lactone, 1,6-diisocyanohexane, ethynylvinyl carbonate, trans-difluorovinyl 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 methylsulfonate. At least one of the following: acyl 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.

[0176] In addition, relative to the total amount of non-aqueous electrolyte, the contents of LiN(CF3SO2)2, LiCF3SO3, LiC4F9SO3, NaN(CF3SO2)2, NaCF3SO3, and NaC4F9SO3 can be between 0.01% by mass and 20% by mass.

[0177] In addition, as in the case of non-aqueous electrolyte batteries, also known as lithium polymer batteries, non-aqueous electrolyte batteries can be used by using gelling agents or cross-linking polymers to solidify the electrolyte before use.

[0178] Furthermore, when the aforementioned other additives are ionic salts, the cation is more preferably lithium ion when used in lithium-ion batteries, and more preferably sodium ion when used in sodium-ion batteries.

[0179] The non-aqueous electrolyte of this application is suitable for use in non-aqueous electrolyte batteries (preferably non-aqueous electrolyte secondary batteries).

[0180] 2. Regarding non-aqueous electrolyte batteries The non-aqueous electrolyte battery of this application includes at least the non-aqueous electrolyte, negative electrode, and positive electrode described above. Furthermore, it may include a separator or casing, etc.

[0181] The non-aqueous electrolyte battery of this application preferably includes at least a positive electrode, a negative electrode, a separator, and the non-aqueous electrolyte of this application.

[0182] The non-aqueous electrolyte battery of this application is preferably a non-aqueous electrolyte secondary battery.

[0183] As a negative electrode, there are no particular limitations; materials in which alkali metal ions, primarily lithium or sodium ions, or alkaline earth metal ions can be reversibly inserted and extracted can be used.

[0184] For example, in the case of lithium-ion secondary batteries where the cation is mainly 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 alone or in combination of two or more. In addition, lithium metal, metal nitrides, tin compounds, conductive polymers, etc., can be used.

[0185] For example, in the case of sodium-ion secondary 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.

[0186] As a positive electrode, there are no particular limitations; materials in which alkali metal ions, primarily lithium or sodium ions, or alkaline earth metal ions can be reversibly inserted and extracted can be used.

[0187] For example, when the cation is lithium, as a positive electrode 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 transition metals; phosphate 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.

[0188] Specifically, Li[Ni] can be listed. 1 / 3 Mn 1 / 3 Co 1 / 3O2, 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, 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 0.5 O4, etc.

[0189] 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 Mn1 / 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 into 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.

[0190] 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. Furthermore, electrode sheets can be formed into sheet shapes.

[0191] As a diaphragm 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.

[0192] Electrochemical devices in shapes such as coin-shaped, cylindrical, square, or aluminum laminate can be assembled from the above elements.

[0193] Example The present application will be specifically described below using examples, but the present application is not limited to these examples.

[0194] The following shows the compounds of components (III), (IV), and (V) used in the various embodiments and comparative examples.

[0195] Component (III) [Chemical Formula 23] Ingredients(IV) LiDFOB: Lithium difluorooxalate borate LiBOB: Lithium dioxalatoborate LiTFOP: Lithium tetrafluorooxalate phosphate LiDFBOP: Lithium difluorobis(oxalato) phosphate LiTOP: Lithium trioxamate phosphate Ingredients (V) LiNO3: Lithium nitrate [Chemical Formula 24] [Chemical Formula 25] [Comparative Examples 0-1 to 0-8, Reference Examples 0-1 to 0-4] <Preparation of electrolytes numbered 0-1 to 0-12> Electrolytes numbered 0-1 to 0-12 were prepared by using a mixed solvent (II) of ethylene carbonate (hereinafter referred to as "EC"), dimethyl carbonate (hereinafter referred to as "DMC"), and ethyl methyl carbonate (hereinafter referred to as "EMC") in a volume ratio of 3:3:4. Lithium hexafluorophosphate (hereinafter referred to as "LiPF6") (hereinafter referred to as "LiPF6") (hereinafter referred to as "I") was dissolved in this solvent to a concentration of 1.0 mol / L; LiN(SO2F)(POF2) or LiN(POF2)2 (hereinafter referred to as "III") was dissolved to a concentration listed in Table 1; LiBOB, LiDFOB, LiTFOP, LiDFBOP, or LiTOP (hereinafter referred to as "IV") was dissolved to a concentration listed in Table 1; and fluoroethylene carbonate (hereinafter referred to as "FEC") was further dissolved to a concentration listed in Table 1. The preparation was carried out while maintaining the liquid temperature at 25°C.

[0196] [Examples 1-1 to 1-16, Comparative Examples 1-1 to 1-19] <Preparation of electrolytes No. 1-1 to 1-36> Except for changing the above components as described in Table 2 and dissolving LiNO3 as (V) in the manner described in Table 2, electrolytes numbered 1-1 to 1-36 were prepared in the same order as the non-aqueous electrolytes in Table 1.

[0197] [Examples 2-1 to 2-22, Comparative Examples 2-1 to 2-27] <Preparation of electrolytes No. 2-1 to 2-49> Except for changing the above components as described in Table 3 and dissolving P(OPh)3, P(OMe)3, P(OEt)3, P(O-isoPr)3 or P(O-HFIP)3 as (V) in the manner described in Table 3, electrolytes numbered 2-1 to 2-49 were prepared in the same order as the non-aqueous electrolytes in Table 1.

[0198] [Examples 3-1 to 3-21, Comparative Examples 3-1 to 3-25] <Preparation of electrolytes No. 3-1 to 3-46> Except for changing the above components as described in Table 4 and dissolving DIPCDI, DCHCDI, DMCDI or DECDI as (V) in the manner described in Table 4, electrolytes numbered 3-1 to 3-46 are prepared in the same order as the non-aqueous electrolytes in Table 1.

[0199] [Storage test of non-aqueous electrolyte at 25°C] The prepared non-aqueous electrolytes were placed into sealed containers and stored at 25°C to obtain the non-aqueous electrolytes of the Examples, Comparative Examples and Reference Examples.

[0200] [Evaluation of the coloration of the non-aqueous electrolyte after storage at 25℃] The degree of coloration of the non-aqueous electrolyte was determined using a colorimeter with Hazen colorimetry (APHA). The APHA values ​​after initial (i.e., after preparation and before storage), after 1 month, after 2 months, and after 4 months are shown in Tables 1-4.

[0201] <Reference Examples 0-1~0-3> It was confirmed that electrolyte 0-9, which does not contain (III) and (IV), did not cause discoloration even after being stored at 25°C for 4 months.

[0202] Furthermore, it was confirmed that electrolyte 0-7, which contains (III) but not (IV), did not cause discoloration even after being stored at 25°C for 4 months.

[0203] Furthermore, it was confirmed that electrolyte 0-8, which does not contain (III) but contains (IV), did not cause discoloration even after being stored at 25°C for 4 months.

[0204] <Comparative Examples 0-1 to 0-6> On the other hand, electrolytes 0-1 to 0-6 containing (III) and (IV), regardless of the type of (IV) or the presence or absence of FEC, confirmed that coloring was achieved by storage at 25°C. This result indicates that non-aqueous electrolytes containing both (III) and (IV) have poor stability compared to conventional electrolytes that do not contain (III) and (IV) (e.g., electrolyte composition equivalent to the comparative example of Patent Document 4).

[0205] <Reference Example 0-4, Comparison Examples 0-7~0-8> The same tendency applies when the type of (III) is changed.

[0206] <Examples 1-1 to 1-16, Comparative Examples 1-1 to 1-19> <Examples 2-1 to 2-22, Comparative Examples 2-1 to 2-27> <Examples 3-1 to 3-21, Comparative Examples 3-1 to 3-25> It was confirmed that if (III)~(V) are present and the value of (V) / {(III)+(IV)} is greater than 0.0040, then staining can be inhibited after storage at 25°C for 4 months.

[0207] On the other hand, it was confirmed that if (III)~(V) are present but the value of (V) / {(III)+(IV)} is less than 0.0040, coloring cannot be suppressed when stored at 25°C.

[0208] [Battery Performance Evaluation] [Fabrication of non-aqueous electrolyte batteries] (Making of NCM811 positive electrode) To 92.0% by mass of LiNi 0.8 Mn 0.1 Co 0.1 O2 powder is mixed with 3.5% by mass of polyvinylidene fluoride (hereinafter also referred to as "PVDF") as a binder and 4.5% by mass of acetylene black as a conductive material, and further additives are added relative to LiNi 0.8 Mn 0.1 Co 0.1 A positive electrode paste was prepared by mixing 45% by mass of N-methylpyrrolidone (hereinafter sometimes referred to as "NMP"), O2 powder, binder, and conductive material. 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.

[0209] (Fabrication of silicon-containing graphite anodes) A negative electrode paste was prepared by mixing 7% by mass nano-silicon, 3% by mass conductive material (manufactured by Denka Company Limited, HS-100), 2% by mass carbon nanofiber (manufactured by Showa Denko KK, VGCF), 2% by mass styrene-butadiene rubber (hereinafter sometimes referred to as "SBR"), 1% by mass carboxymethyl cellulose (hereinafter sometimes referred to as "CMC"), and water into 85% by mass 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 negative electrode.

[0210] (Fabrication of non-aqueous electrolyte batteries) In an argon atmosphere with a dew point below -50°C, after the terminals are fused to the aforementioned NCM811 positive electrode, two polyethylene separators (5cm × 6cm) are used to clamp both sides of the electrode, so that the active material side of the negative electrode faces the active material side of the positive electrode. Then, two natural graphite negative electrodes with pre-fused terminals are used to clamp the outer sides. Next, they are placed into an aluminum-laminated bag with an opening on one side, and a non-aqueous electrolyte is vacuum-injected. The opening is then sealed by heat, thereby producing the aluminum-laminated non-aqueous electrolyte batteries of the examples, comparative examples, and reference examples in Table 5.

[0211] [evaluate] <Initial Charge and Discharge Test> 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: charge at a constant current and constant voltage of 5mA with the upper limit charging voltage of 4.2V, then discharge at a constant current of 10mA until the discharge termination voltage reaches 2.5V; then charge at a constant current and constant voltage of 10mA with the upper limit charging voltage of 4.2V, then discharge at a constant current of 10mA until the discharge termination voltage reaches 2.5V. Set the discharge capacity of the third cycle as the initial discharge capacity.

[0212] <Cyclic Test (60℃)> The non-aqueous electrolyte battery, having completed the initial charge-discharge test, was subjected to constant current discharge at 10mA at an ambient temperature of 25°C until the discharge termination voltage reached 2.5V, and then left to stand at an ambient temperature of 60°C for 3 hours. Then, it was charged at a constant current and constant voltage of 75mA at the upper limit of the charging voltage (4.2V), and discharged at a constant current of 75mA until the discharge termination voltage reached 2.5V. This charge-discharge cycle at 60°C and 75mA was repeated 500 times. Then, at an ambient temperature of 25°C, it was left to stand for 3 hours, charged at a constant current and constant voltage of 10mA at the upper limit of the charging voltage (4.2V), and discharged at a constant current of 10mA until the discharge termination voltage reached 2.5V. The discharge capacity of this discharged battery was taken as the discharge capacity after the cycle test.

[0213] <Cycle Retention Rate Evaluation> The capacity retention rate after cycling tests is calculated using the following formula. The larger the value, the better the high-temperature cycling characteristics.

[0214] Capacity retention after cycle test (%) = (Discharge capacity after cycle test / Initial discharge capacity) × 100 <Internal Resistance Measurement> The non-aqueous electrolyte batteries were charged with a constant current of 10mA for 150 minutes before and after the 60°C cycle test at an ambient temperature of 25°C. They were then discharged with a constant current of 10 seconds at specified current values ​​(5mA, 10mA, 25mA, 50mA, 100mA). The voltage at the 10th second was measured and plotted against the current value. The least squares method was applied to each graph to obtain an approximate straight line. The slope of the approximate straight line was set as the initial internal resistance and the internal resistance after the cycle test.

[0215] <Evaluation of Increased Internal Resistance> The rate of increase in internal resistance after the cycle test is calculated using the following formula.

[0216] Increase rate of internal resistance at low temperature after cycle test (%) = (Internal resistance after cycle test / Initial internal resistance) × 100 The smaller the value, the better the suppression effect of internal resistance rise.

[0217] <Gas Production Measurement> At an ambient temperature of 25°C, the increase in battery volume of the non-aqueous electrolyte battery before and after the 60°C cycling test was estimated using the buoyancy method with silicone oil, thereby evaluating the amount of gas generated. The smaller the value, the higher the gas suppression effect.

[0218] In addition, the capacity retention rate, the increase rate of low-temperature internal resistance after the cycle test, and the amount of gas generated in Table 5 are relative values ​​when Comparative Example 0-1e is set to 100.

[0219] Compared to Comparative Example 0-1e (0-1), which used an electrolyte containing (III) and (IV), all battery characteristics of Reference Examples 0-1e to 0-3e (0-7 to 0-9), which used non-aqueous electrolytes without the addition of either (III) or (IV), or without both, were worse than Comparative Example 0-1e. This result indicates that non-aqueous electrolytes containing (III) and (IV) exhibit superior battery performance.

[0220] Furthermore, the same applies to Comparative Examples 0-7e, which use electrolytes of different types (III) numbered 0-10 (comparison of Comparative Examples 0-7e with Reference Examples 0-2e~0-4e).

[0221] On the other hand, in the embodiments listed in Table 5 that used non-aqueous electrolytes containing (V) in electrolyte numbers 0-1 or 0-2, no adverse effects on battery performance were identified. This result indicates that (V) has almost no adverse effect on battery performance and can improve the stability of the non-aqueous electrolyte itself.

[0222] Industrial applicability According to this application, a non-aqueous electrolyte and a non-aqueous electrolyte battery using the non-aqueous electrolyte can be provided. The non-aqueous electrolyte exhibits excellent battery performance when used to manufacture a non-aqueous electrolyte battery and can suppress discoloration during long-term storage at room temperature (25°C).

[0223] Although this application 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 this application.

[0224] Furthermore, this application is based on Japanese patent applications filed on August 30, 2023 (Japanese Patent Application No. 2023-140511) and February 28, 2024 (Japanese Patent Application No. 2024-028755), the contents of which are incorporated herein by reference.

Claims

1. A non-aqueous electrolyte, comprising: (I) Solute, (II) Non-aqueous organic solvents, (III) The compounds represented by the following general formula (1), (IV) Compounds represented by the following general formula (4), and (V) is selected from at least one compound from the group consisting of nitrates, compounds represented by the following general formula (2) and compounds represented by the following general formula (3). in, The mass ratio of (V) to the total mass of (III) and (IV), (V) / {(III) + (IV)}, is 0.0040 or higher. [Chemical Formula 1] ， In general formula (1), M a1＋ For alkali metal cations, alkaline earth metal cations, or onium cations, a1 represents an integer with the same valence as the corresponding cation; a1~d1 represent integers from 1 to 2 that satisfy a1×b1=c1×d1; 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 4 Each of the following organic groups is independently selected from fluorine atoms, oxygen atoms, alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, alkenyloxy groups having 2 to 10 carbon atoms, alkynyl groups having 2 to 10 carbon atoms, alkynyloxy groups having 2 to 10 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, cycloalkoxy groups having 3 to 10 carbon atoms, cycloalkenyl groups having 3 to 10 carbon atoms, cycloalkenyloxy groups having 3 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and aryloxy groups having 6 to 10 carbon atoms, wherein the organic group optionally contains fluorine atoms, oxygen atoms, and / or unsaturated bonds. [Chemical Formula 2] ， In general formula (4), W represents a boron atom, a phosphorus atom, or a silicon atom, n1 is 1 or 2, n2 is 2 or 4, and e is 0 or 1; when e is 0, R does not exist. 41 R 41 Y recorded on both sides of the adjacent 3 Directly bonded to the carbonyl group; R 41 The groups represent alkylene groups having 1 to 10 carbon atoms, haloalkylene groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, haloalkenyl groups having 2 to 10 carbon atoms, aryl groups having 6 to 20 carbon atoms, or haloaryl groups having 6 to 20 carbon atoms, wherein these groups optionally contain heteroatoms in their structure; furthermore, when n1 is 2 or more, the n1 R groups present... 41 Optional mutual bonding, R 42 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 When Y3 is a carbon atom, f is 1; when Y3 is a sulfur atom, f 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 1 or 2 and satisfy a × b = c × d. [Chemical Formula 3] ， In general formula (2), p, q, and r each independently represent 0 or 1, and R 5 ~R 7 Each is independently a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms that are optionally partially or wholly substituted with fluorine, R 5 With R 6 R 5 With R 7 、or R 6 With R 7 They can be arbitrarily bonded together to form a ring structure. [Chemical Formula 4] ， In general formula (3), R 8 and R 9 Each is an independent hydrocarbon group with 1 to 20 carbon atoms.

2. The non-aqueous electrolyte according to claim 1, wherein, The value of (V) / {(III)+(IV)} is 0.0100~1.5000.

3. The non-aqueous electrolyte according to claim 1, wherein, R in the general formula (1) 1 ~R 4 At least one of them is a fluorine atom.

4. The non-aqueous electrolyte according to claim 1, wherein, The compound represented by the general formula (1) is a bis(difluorophosphoryl)imine salt or a (fluorosulfonyl)(difluorophosphoryl)imine salt.

5. The non-aqueous electrolyte according to claim 1, wherein, The compound represented by the general formula (4) is an oxalate compound.

6. The non-aqueous electrolyte according to claim 1, wherein, In the general formula (2), q, r, and s are all 1, and R is... 5 ~R 7 All identical hydrocarbon groups having 1 to 20 carbon atoms that are partially or entirely substituted with fluorine.

7. The non-aqueous electrolyte according to claim 1, wherein, R, as in the general formula (3) 8 R 9 The atom bonded to the nitrogen atom is a secondary carbon atom.

8. The non-aqueous electrolyte according to claim 1, wherein, The compound represented by the general formula (3) is at least one selected from the group consisting of N,N'-diisopropylcarbodiimide and N,N'-dicyclohexylcarbodiimide.

9. The non-aqueous electrolyte according to claim 1, wherein, The (V) contains nitrates, and the nitrate content is less than 1% by mass relative to the total amount of the non-aqueous electrolyte.

10. The non-aqueous electrolyte according to claim 1, wherein, The non-aqueous electrolyte contains fluoroethylene carbonate.

11. The non-aqueous electrolyte according to claim 1, wherein, The (I) is selected from at least one of the group consisting of LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiN(FSO2)2, LiAlO2, LiAlCl4, LiCl and LiI.

12. The non-aqueous electrolyte according to claim 1, wherein, The (I) is selected from at least one of the group consisting of NaPF6, NaBF4, NaSbF6, NaAsF6, NaClO4, NaN(FSO2)2, NaAlO2, NaAlCl4, NaCl and NaI.

13. The non-aqueous electrolyte according to claim 1, wherein, The (II) 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.

14. The non-aqueous electrolyte according to claim 13, wherein, The cyclic ester comprises cyclic carbonates.

15. The non-aqueous electrolyte according to claim 14, wherein, The cyclic carbonate comprises at least one selected from the group consisting of ethylene carbonate and propylene carbonate.

16. The non-aqueous electrolyte according to claim 13, wherein, The chain ester comprises chain carbonates.

17. The non-aqueous electrolyte according to claim 16, wherein, The chain carbonate is at least one selected from the group consisting of methyl ethyl carbonate, dimethyl carbonate, diethyl carbonate, and methyl propyl carbonate.

18. The non-aqueous electrolyte according to claim 1, further comprising a mixture selected from vinylene carbonate, difluorophosphate, fluorosulfonate, propylene-1,3-sulactone, 1,3-propanesulfonyl, 1,6-diisocyanohexane, ethynylvinyl carbonate, trans-difluorovinyl carbonate, 1,3,2-dioxazothiophene-2,2-dioxide, 4-propyl-1,3,2-dioxazothiophene-2,2-dioxide, methanedisulfonic acid methylene, 1,2-ethanedisulfonic anhydride, and methanesulfonic anhydride. At least one of the following: methanesulfonyl 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.

19. 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 18.

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