Non-aqueous electrolyte and energy device using the same

Abstract

Provided is a non-aqueous electrolyte that can be handled stably industrially, and that has good durability in energy devices as represented by a non-aqueous electrolyte secondary battery, particularly capacity retention during repeated charging and discharging. The non-aqueous electrolyte contains a compound represented by general formula (A1) and / or (A2). In formula (A1), X1 is a halogen atom, and R1, R2, R5, and R6 each independently represent a hydrogen atom, a halogen atom, or a hydrocarbon group of C10 or lower that may be substituted with a halogen atom. R3 and R4 each independently represent a halogen atom or a hydrocarbon group of C10 or lower that may be substituted with a halogen atom. R1 to R6 may be bonded to form a ring. In formula (A2), X2 and X3 each independently are halogen atoms. R7 to R14 each independently represent a hydrogen atom, a halogen atom, or a hydrocarbon group of C10 or lower that may be substituted with a halogen atom. R7 to R14 may also be bonded to form a ring.

Description

Nonaqueous electrolyte and energy device using same

[0001] The present invention relates to a non-aqueous electrolyte solution and an energy device using the same.

[0002] Energy devices using nonaqueous electrolytes, such as nonaqueous electrolyte secondary batteries, electric double layer capacitors, and lithium ion capacitors, have been put to practical use in a wide range of applications, from so-called consumer power sources such as mobile phones and laptop computers to on-board power sources for driving automobiles and large-scale stationary power sources. However, in recent years, there has been an increasing demand for higher performance in energy devices. In particular, nonaqueous electrolyte secondary batteries are required to achieve high levels of battery characteristics, such as capacity, swelling, input / output, charge / discharge rate characteristics, and safety, not only initially but also after endurance such as cycling and storage. There is also a demand for safe and stable production and supply of these nonaqueous electrolyte secondary batteries.

[0003] To date, numerous technologies have been investigated for various battery components, including the active materials of the positive and negative electrodes and the nonaqueous electrolyte, as means for improving the capacity, input / output, charge / discharge rate, battery swelling, positive electrode metal elution, and safety of nonaqueous electrolyte secondary batteries in their initial state and after endurance such as cycling and storage.

[0004] To solve these problems, various electrolyte solutions containing halophosphate diester compounds substituted with hydrocarbon groups have been proposed. The expected effects of using such phosphate ester compounds as additives include the fact that the phosphate ester compounds react in the electrolyte to become compounds that contribute to improving battery characteristics, and that the flame retardancy of the electrolyte due to the flame retardant effect of the phosphorus atom can simultaneously be achieved, thereby improving safety.

[0005] For example, Patent Document 1 discloses a technique for improving the capacity retention rate after cycling and after high-temperature storage by using an electrolyte solution containing a specific fluorophosphate ester compound.

[0006] Patent Document 2 discloses a technique that can reduce the initial battery resistance by using an electrolyte solution containing a specific fluorophosphate ester compound.

[0007] Patent Document 3 discloses a technique that can improve battery resistance and capacity retention rate by using an electrolyte solution containing a specific fluorophosphate ester compound.

[0008] Patent Documents 4 and 5 disclose techniques that can reduce battery resistance and improve capacity retention by using an electrolyte solution containing a phosphate ester compound.

[0009] JP 2002-141110 A JP 2016-201177 A JP 2019-153443 A WO 2012 / 118179 A JP 2014-179247 A

[0010] As described above, in recent years, there has been an increasing demand for higher performance in non-aqueous electrolyte secondary batteries, and further improvements in the performance of non-aqueous electrolyte secondary batteries, particularly improvements in initial performance and durability, such as repeated charge / discharge and storage characteristics, are required. On the other hand, since these non-aqueous electrolytes are used industrially, it is well known that it is important that the safety of the components contained therein, particularly excellent thermal stability, is important. That is, compounds with low thermal stability may cause unintended decomposition reactions during the production of the compound itself, during the production of the electrolyte solution, and during the storage, transportation, and use of the electrolyte solution, and in some cases, may cause serious damage such as explosion accidents. Therefore, even if an electrolyte containing such a compound has excellent battery characteristics, it cannot be used suitably.

[0011] From this perspective, it is difficult to say that nonaqueous electrolyte batteries using the compounds described in Patent Documents 1 and 2 have yet to achieve sufficient improvements in battery performance, particularly in capacity retention during repeated charge and discharge. Furthermore, Patent Documents 1, 2, and 3 do not disclose the thermal stability of the compounds. The inventors' investigations revealed that the compounds described in the examples have significantly low thermal stability and are therefore unsuitable for industrial use. Furthermore, the technology disclosed in Patent Document 4 uses a large amount of a dialkyl fluorophosphate ester compound, which is more expensive than the carbonate-based solvents typically used in electrolytes, and therefore presents problems from the perspective of industrial use. Furthermore, while the flame retardancy of the electrolyte is discussed in terms of flammability upon contact with flame, the discussion does not address the thermal stability of the electrolyte itself, and there is room for improvement in terms of safety during handling of nonaqueous electrolytes during production, storage, and use.

[0012] In view of the background art, a first object of the present invention is to provide a nonaqueous electrolyte that can be handled stably on an industrial scale and that provides a good durability performance of an energy device, typified by a nonaqueous electrolyte secondary battery, in particular a good capacity retention rate during repeated charge and discharge.

[0013] As mentioned above, recent non-aqueous electrolyte secondary batteries are required to have improved initial performance and durability in terms of repeated charge / discharge and storage characteristics, etc. Meanwhile, due to the recent demand for higher energy density, attention has been focused on the development of negative electrode active materials containing materials other than carbon materials.

[0014] The compounds described in Patent Documents 1 to 5 are based on the premise that they are suitable for use in a negative electrode active material consisting solely of a conventionally used carbon material, and therefore no consideration has been given to phosphate ester compounds that can be suitably used when a negative electrode active material containing a material other than the above-mentioned carbon material is used. Furthermore, as a result of extensive research by the inventors, it has been found that some of the phosphate ester compounds disclosed as being preferable in these documents, when combined with a negative electrode active material containing a material other than a carbon material, actually degrade the performance of the secondary battery, particularly the capacity retention characteristics during repeated charge and discharge.

[0015] In view of the background art, a second object of the present invention is to provide an energy device, typified by a non-aqueous electrolyte secondary battery, which has good capacity and durability, particularly good capacity retention rate during repeated charge and discharge.

[0016] As a result of extensive research to achieve the first object, the present inventors have found that by incorporating a compound represented by general formula (A1) and / or (A2) described below into a nonaqueous electrolyte solution, it is possible to provide a nonaqueous electrolyte solution that can be handled stably on an industrial scale and that has good durability performance of an energy device, typified by a nonaqueous electrolyte secondary battery, in particular, good capacity retention rate during repeated charge and discharge, and have thereby completed the present invention.

[0017] That is, the first aspect of the present invention provides specific aspects shown in [A1] to [A9] below: [A1] A non-aqueous electrolyte solution containing a compound represented by the following general formula (A1) and / or (A2): (In formula (A1), X １ is a halogen atom, and R １ , R ２ , R ５ , and R ６ R each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom. ３ and R ４ each independently represents a halogen atom or a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom. １ ~R ６ may be bonded to form a ring.) (In formula (A2), X ２ and X ３ are each independently a halogen atom. ７ ~R １４ each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom. ７ ~R １４ may be bonded to form a ring. [A2] In the formula (A1), R １ , R ２ , R ５ , and R ６[A3] The nonaqueous electrolyte solution according to [A1], wherein X in the formula (A1) is a hydrogen atom. １ [A4] The nonaqueous electrolyte solution according to [A1] or [A2], wherein R in the formula (A2) is a fluorine atom. ７ ~R １４ [A5] The nonaqueous electrolyte solution according to [A1], wherein all of X in the formula (A2) are hydrogen atoms. ２ , and X ３ is a fluorine atom. [A6] The nonaqueous electrolyte solution according to any one of [A1] to [A5], containing at least one organic solvent selected from the group consisting of saturated cyclic carbonates, chain carbonates, chain carboxylic acid esters, cyclic carboxylic acid esters, ether-based compounds, and sulfone-based compounds. [A7] The nonaqueous electrolyte solution according to any one of [A1] to [A6], wherein the total content of the compounds represented by general formulas (A1) and (A2) is 0.001% by mass or more and 30% by mass or less, based on the total amount of the nonaqueous electrolyte solution. [A8] An energy device comprising a plurality of electrodes capable of absorbing and releasing metal ions and the nonaqueous electrolyte solution according to any one of [A1] to [A7]. [A9] A compound represented by the following formula (A3):

[0018] Furthermore, as a result of extensive research into solving the second problem, the present inventors have found that by incorporating a compound represented by general formula (B1) and / or (B2) described below into a nonaqueous electrolyte solution, it is possible to provide a nonaqueous electrolyte solution that can be suitably used in an energy device that uses a negative electrode active material containing a silicon atom, and have thereby completed the present invention.

[0019] More specifically, in order to develop a novel nonaqueous electrolyte that significantly improves upon the above-mentioned problems compared to conventional technologies, the present inventors conducted extensive studies on the effects of various compounds, focusing on the mechanism of formation of the negative electrode coating and elementary reaction rate of nonaqueous electrolyte secondary batteries as energy devices, as well as the mechanism of stabilization of the positive electrode surface. Furthermore, they conducted extensive studies on the decomposition mechanism of the compounds and carried out optimal molecular design. The present inventors then developed a technology that can improve upon the above-mentioned problems through the novel idea of ​​incorporating specific halophosphate ester compounds represented by the general formula (B1) and / or (B2) described below into a nonaqueous electrolyte and further combining the compound with a specific negative electrode to form an energy device.

[0020] That is, a second aspect of the present invention provides specific aspects shown in the following [B1] to [B9]: [B1] An energy device including a positive electrode capable of absorbing and desorbing metal ions, a negative electrode capable of absorbing and desorbing metal ions, and a non-aqueous electrolyte solution, wherein the negative electrode contains a negative electrode active material containing a silicon atom, and the non-aqueous electrolyte solution contains at least one compound selected from the group consisting of compounds represented by the following general formulas (B1) and (B2): (In general formula (B1), X １ ' is a halogen atom, and Y is a divalent alkyl group having 2 to 4 carbon atoms that forms a ring together with a part of the halogenated phosphate ester. However, the hydrogen atom on the carbon atom that forms the ring of Y may be substituted with a halogen atom or an organic group having 6 or less carbon atoms. (In general formula (B2), X ２ ' and X ３Each ' is independently a halogen atom, and Z represents a tetravalent alkyl group having 4 to 8 carbon atoms that forms a ring together with a portion of the halogenated phosphate ester. However, a hydrogen atom on a carbon atom that forms a ring in Z may be substituted with a halogen atom or an organic group having 6 or less carbon atoms.) [B2] The energy device according to [B1], wherein in Y of the general formula (B1), the number of carbon atoms that form a ring together with a portion of the halogenated phosphate ester is 3. [B3] The energy device according to [B1] or [B2], wherein at least one hydrogen atom on a carbon atom that forms a ring in Y of the general formula (B1) is substituted with a fluorine atom. [B4] The energy device according to [B1], wherein X of the general formula (B1) １ [B5] The energy device according to any one of [B1] to [B3], wherein Z in the general formula (B2) has 5 carbon atoms constituting a ring together with a portion of the halogenated phosphate ester. [B6] The energy device according to [B5], wherein at least one hydrogen atom of a carbon atom constituting a ring in Z in the general formula (B2) is substituted with a fluorine atom. [B7] The energy device according to any one of [B1] to [B3], wherein X in the general formula (B2) ２ ' and X ３ The energy device according to any one of [B1], [B5] and [B6], wherein "'" is a fluorine atom. [B8] The energy device according to any one of [B1] to [B7], wherein the non-aqueous electrolyte solution contains at least one compound selected from the group consisting of saturated cyclic carbonates, chain carbonates, chain carboxylic acid esters, cyclic carboxylic acid esters, ether-based compounds and sulfone-based compounds. [B9] The energy device according to any one of [B1] to [B8], wherein the total content of the compounds represented by general formulas (B1) and (B2) is 0.001 mass % or more and 30 mass % or less with respect to the total amount of the non-aqueous electrolyte solution.

[0021] According to a first aspect of the present invention, a nonaqueous electrolyte can be provided that can be handled industrially stably and that exhibits good durability, particularly good capacity retention during repeated charge and discharge, in an energy device typified by a nonaqueous electrolyte secondary battery. Also, according to a second aspect of the present invention, an energy device typified by a nonaqueous electrolyte secondary battery exhibits good capacity retention during repeated charge and discharge.

[0022] Hereinafter, embodiments of the present invention will be described in detail. The following embodiments are examples (typical examples) of the present invention, and the present invention is not limited to these. Furthermore, the present invention can be implemented with any modifications within the scope of the gist of the present invention. In this specification, a statement expressed as "to" indicates a range including the numbers written before and after it.

[0023] <1. Nonaqueous Electrolyte Solution> <1-1. Components Contained in the Nonaqueous Electrolyte Solution> <1-1-1. Halogenated Phosphate Ester Compound Used in First Embodiment> The first embodiment of the nonaqueous electrolyte solution contains a compound represented by the following general formula (A1) and / or a compound represented by the following general formula (A2) (hereinafter, these may be referred to as the "halogenated phosphate ester compound used in the first embodiment").

[0024] In the formula (A1), X １ is a halogen atom, and R １ , R ２ , R ５ , and R ６ R each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom. ３ and R ４ each independently represents a halogen atom or a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom. １ ~R ６ may be bonded to form a ring.

[0025]

[0026] In the formula (A2), X ２ and X ３are each independently a halogen atom. ７ ~R １４ R each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom. ７ ~R １４ may be bonded to form a ring.

[0027] [1-1-1-2. X １ In the formula (A1), X １ represents a halogen atom. Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Of these, a fluorine atom is preferred. X １ By using fluorine atoms, when the battery is used in an energy device, the coating on the surface of the negative electrode is stabilized, which suppresses side reactions between the components of the electrolyte and the negative electrode, improving the capacity retention rate during repeated charge and discharge.

[0028] [1-1-1-3. R １ , R ２ , R ５ , R ６ In the formula (A1), R １ , R ２ , R ５ , and R ６ R each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom. When used in an energy device, R is preferred in that it can more easily improve the overall properties of the energy device, such as the capacity retention rate during repeated charging. １ , R ２ , R ５ , and R ６ Preferably, at least one of R is not a hydrogen atom, １ , R ２ , R ５ , and R ６ On the other hand, it is particularly preferable that at least one of R is a halogen atom, in terms of ease of industrial handling in all steps of producing and storing the halogenated phosphate ester compound used in the first embodiment, and producing and using the electrolyte solution. １ , R ２ , R ５ , and R ６are also preferably all hydrogen atoms.

[0029] Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom is preferred because, when used as an energy device, the coating on the negative electrode surface is stabilized, thereby suppressing side reactions between the electrolyte components and the negative electrode and making it easier to further improve properties such as the capacity retention rate during repeated charge and discharge.

[0030] Specific examples of the hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom include a hydrocarbon group and a hydrocarbon group substituted with a halogen atom. Of these, a hydrocarbon group is preferred in terms of ease of industrial handling in all steps, including production and storage of the halogenated phosphate ester compound used in the first embodiment, and production and use of the electrolyte solution. A hydrocarbon group substituted with a halogen atom is preferred in terms of improving properties such as capacity retention rate during repeated charging when used in an energy device. Here, specific examples of the halogen atom substituting the hydrocarbon group in a halogen-substituted hydrocarbon group include the specific examples of halogen atoms described above.

[0031] Specific examples of the hydrocarbon group include saturated hydrocarbon groups and hydrocarbon groups having an unsaturated bond, but among these, saturated hydrocarbon groups are preferred because they can easily improve properties such as capacity retention rate during repeated charging when used in an energy device.

[0032] Specific examples of the saturated hydrocarbon group include a linear or branched alkyl group and an alkyl group having a partial cyclic structure. Among these, a linear or branched alkyl group is preferred, and a linear alkyl group is more preferred, in that it is easy to improve properties such as capacity retention rate during repeated charging when used in an energy device.

[0033] Specific examples of the linear alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, and an n-decyl group. Among these, the alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and particularly preferably 1 carbon atom, in terms of facilitating improvement in properties such as capacity retention rate during repeated charging when used in an energy device.

[0034] Specific examples of branched alkyl groups include a methylethyl group, a methylbutyl group, a methylpentyl group, a methylhexyl group, a methylheptyl group, a methyloctyl group, a methylnonyl group; a dimethylethyl group, a dimethylpropyl group, a dimethylbutyl group, a dimethylpentyl group, a dimethylhexyl group, a dimethylheptyl group, a dimethyloctyl group; a trimethylhexyl group, a trimethylheptyl group; an ethylpentyl group, an ethylhexyl group, an ethylheptyl group, an ethyloctyl group; a propylhexyl group, a propylheptyl group; and a butylhexyl group.

[0035] Among these, in terms of facilitating improvement of properties such as capacity retention rate during repeated charging when used in an energy device, the number of carbon atoms in the alkyl group is preferably 3 to 5, and particularly preferably 3 to 4. In the examples of the branched alkyl group, the branch position is optional.

[0036] Specific examples of the alkyl group having a partially cyclic structure include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, and a cyclodecyl group; a cyclopropylmethyl group, a cyclobutylmethyl group, a cyclopentylmethyl group, a cyclohexylmethyl group, a cycloheptylmethyl group, a cyclooctylmethyl group, and a cyclononylmethyl group; a cyclopropylethyl group, a cyclobutylethyl group, a cyclopentylethyl group, a cyclohexylethyl group, a cycloheptylethyl group, and a cyclooctylethyl group; a cyclopropylpropyl group, a cyclobutylpropyl group, a cyclopentylpropyl group, a cyclohexylpropyl group, and a cycloheptylpropyl group; a methylcyclopropyl group, a methylcyclobutyl group, a methylcyclopentyl group, a methylcyclohexyl group, a methylcycloheptyl group, a methylcyclooctyl group, and a methylcyclononyl group; a dimethylcyclopropyl group, a dimethylcyclobutyl group, a dimethylcyclopentyl group, a dimethylcyclohexyl group, a dimethylcycloheptyl group, and a dimethylcyclooctyl group; Examples include an ethylcyclopropyl group, an ethylcyclobutyl group, an ethylcyclopentyl group, an ethylcyclohexyl group, an ethylcycloheptyl group, an ethylcyclooctyl group; a propylcyclopropyl group, a propylcyclobutyl group, a propylcyclopentyl group, a propylcyclohexyl group, a propylcycloheptyl group; a methylcyclohexylmethyl group, a methylcycloheptylmethyl group, a methylcyclooctylmethyl group; a dimethylcyclohexylmethyl group, a dimethylcycloheptylmethyl group; a dimethylcyclohexylethyl group, a dimethylcycloheptylethyl group; and a dimethylcyclohexylpropyl group. However, the alkyl group preferably has 3 to 7 carbon atoms, as this facilitates improving properties such as capacity retention rate during repeated charging when used in an energy device.

[0037] Specific examples of hydrocarbon groups having an unsaturated bond are not particularly limited as long as they have a structure in which the saturated hydrocarbon group has one or more carbon-carbon double or triple bonds, and specific examples include ethenyl, ethynyl, allyl, 2-propynyl, isopropenyl, 1-cyclohexenyl, and phenyl groups. Of these, in order to facilitate the dissolution of the halogenated phosphate ester compound of this embodiment in an electrolyte solution, those having 3 or less carbon atoms are preferred, ethenyl or allyl groups are more preferred, and ethenyl groups are particularly preferred.

[0038] Specific examples of hydrocarbon groups substituted with halogen atoms include saturated hydrocarbon groups and unsaturated hydrocarbon groups in which some hydrogen atoms have been substituted with halogen atoms. The number of substituted halogen atoms is preferably 1 to 5, and particularly preferably 1 to 3.

[0039] [1-1-1-4. R ３ and R ４ In the formula (A1), R ３ and R ４ R each independently represents a halogen atom or a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom. ３ and R ４ may be the same or different, but are preferably the same in terms of industrial ease of handling in all steps, including production and storage of the halogenated phosphate ester compound used in the first embodiment, and production and use of the electrolyte solution. R is preferably the same in terms of facilitating further improvement of properties such as capacity retention rate during repeated charge and discharge when used in an energy device. ３ and R ４is preferably a halogen atom. Specific examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. Of these, fluorine atoms are preferred because, when used as an energy device, the coating on the negative electrode surface is stabilized, thereby suppressing side reactions of electrolyte components with the negative electrode and further improving properties such as capacity retention during repeated charge and discharge. A hydrocarbon group that may be substituted with a halogen is preferred because it is industrially easy to handle in all steps, including production, storage, and production and use of the electrolyte, of the halogenated phosphate ester compound used in the first embodiment. Specific examples of hydrocarbon groups having 10 or less carbon atoms that may be substituted with a halogen atom include hydrocarbon groups and hydrocarbon groups substituted with a halogen atom. Of these, hydrocarbon groups are preferred because they are industrially easy to handle in all steps, including production, storage, and production and use of the electrolyte, of the halogenated phosphate ester compound used in the first embodiment, and halogen-substituted hydrocarbon groups are preferred because they are industrially easy to handle in all steps, including production, storage, and production and use of the electrolyte, of the halogenated phosphate ester compound used in the first embodiment. Here, in the hydrocarbon group substituted with a halogen atom, specific examples of the halogen atom substituting the hydrocarbon group include the specific examples of the halogen atom described above. Specific examples and preferred examples of the hydrocarbon group and the hydrocarbon group substituted with a halogen atom are described in the above-mentioned R １ , R ２ , R ５ , and R ６ The halogenated phosphate ester compound used in the first embodiment is easy to handle industrially in all steps, including production and storage of the compound, and production and use of the electrolyte solution. ３ and R ４ is preferably a methyl group.

[0040] Also, R １ ~R ６ can be linked to form a ring. １ ~R ６ Specific examples of the embodiment in which R are bonded to form a ring include R １ and R 2 , R １ and R3 , R １ and R 5 , R 3 and R 4 , and R 5 and R 6 are bonded to form a ring, but a preferred embodiment is 3 and R 4 are bonded to form a ring.

[0041] The most preferred R １ ~R ６ As an embodiment of R ３ and R ４ is a fluorine atom, and R １ , R ２ , R ５ and R ６ is a hydrogen atom, or R ３ and R ４ is a methyl group, and R １ , R ２ , R ５ and R ６ is a hydrogen atom.

[0042] [1-1-1-5. X ２ and X ３ ] In the formula (A2), X ２ and X ３ Each of the groups independently represents a halogen atom. Specific and preferred examples of the group are the above-mentioned X １ It is the same as the specific examples of X. ２ and X ３ may be the same or different, but are preferably the same in terms of industrial ease of handling in all steps, including production and storage of the halogenated phosphate ester used in the first embodiment, and production and use of the electrolyte solution.

[0043] [1-1-1-6. R ７ ~R １４ ] In the formula (A2), R ７ ~R １４each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a halogen atom. However, in terms of industrial ease of handling in all steps during the production and storage of the halogenated phosphate ester compound used in the first embodiment, and during the production and use of the electrolyte solution, R ７ ~R １４ It is also preferred that all of R are hydrogen atoms. Specific and preferred examples of halogen atoms and hydrocarbon groups having 1 to 10 carbon atoms which may be substituted with halogen atoms are １ , R ２ , R ５ , R ６ This is similar to the specific examples given above.

[0044] The halogenated phosphate ester compound used in the first embodiment preferably has an exotherm onset temperature of 190°C or higher, more preferably 200°C or higher, and particularly preferably 220°C or higher, as measured by differential scanning calorimetry (DSC) under a nitrogen stream. Having an exotherm onset temperature equal to or higher than the lower limit mentioned above makes the halogenated phosphate ester compound used in the first embodiment easy to handle industrially in all steps, including production, storage, and production and use of the electrolyte. The upper limit of the exotherm onset temperature is not particularly specified, but is usually 450°C or lower. The exotherm onset temperature is the calorific value height H at 70°C when the temperature is increased at 10°C / min in the temperature range from 20°C to 400°C, as measured by DSC under a nitrogen stream. １ and the heat generation height H at the maximum heat generation peak temperature ＭＡＸ The difference between １ and the heat generation height H １ When the calorific value is based on ΔH １ This is the temperature at which the temperature reaches 5% of the original value.

[0045] <1-1-1-7. Specific Examples> Specific examples of the halogenated phosphate ester compound used in the first embodiment are described below. Note that the halogenated phosphate ester compound used in the first embodiment is not limited to the examples exemplified here.

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056] Among these, the following compounds are preferred from the viewpoint of industrial handling in all steps during the production and storage of the halogenated phosphate ester compound used in the first embodiment, and during the production and use of the electrolyte solution.

[0057]

[0058] Among these, the following compounds are more preferred from the viewpoint that when the compound is used in an energy device, the coating on the negative electrode surface is stabilized and the overall properties of the energy device, such as the capacity retention rate during repeated charge and discharge and storage characteristics, are more easily improved.

[0059]

[0060] The halogenated phosphate ester compounds used in the first embodiment may be used alone or in any combination and ratio of two or more. The content of the halogenated phosphate ester compounds used in the first embodiment is not particularly limited and may be any content as long as it does not significantly impair the effects of the present invention. However, the total content of the compounds represented by the general formulas (A1) and (A2) is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and particularly preferably 0.1% by mass or more, relative to the total amount of the non-aqueous electrolyte solution. By being within this range, a suitable coating is formed on the negative electrode surface, and the effect of suppressing side reactions of the electrolyte solution components is exerted, thereby significantly improving the cycle capacity retention rate during repeated charge and discharge. Meanwhile, the total content of the compounds represented by the general formulas (A1) and (A2) is preferably 30% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less, relative to the total amount of the non-aqueous electrolyte solution. Within the above range, an excessive negative electrode coating is not formed, and the permeability of lithium ions can be ensured, so that the input / output characteristics and charge / discharge rate characteristics fall within suitable ranges.

[0061] The method for producing the compounds represented by general formulas (A1) and (A2) is not particularly limited, and they can be produced by combining known methods. For example, there are methods using a cyclization reaction between a phosphoryl halide and a polyhydric alcohol, a cyclization reaction between a chain phosphate halide and a polyhydric alcohol, an oxidative halogenation reaction of a cyclic phosphonic acid, an oxidation reaction of a cyclic phosphonic acid halide, a halogenation reaction by substitution reaction of a cyclic phosphate ester, and a substitution reaction on a hydrocarbon group of a cyclic phosphate halide, an addition reaction, or a method of introducing or removing a substituent by elimination reaction. In addition, the halogen atom on the phosphorus of the cyclic phosphate halide can be replaced with a different halogen atom by substitution reaction. Furthermore, oxygen nucleophiles or carbon electrophiles derived from cyclic carbonates, etc., and LiPF ６ and a method for producing the same in an electrolyte by reacting a compound containing a phosphorus atom, such as the above, or a substance derived therefrom with itself.

[0062] The preparation of the non-aqueous electrolyte solution containing the compound represented by general formula (A1) and / or (A2) may be carried out by a known method, and is not particularly limited. For example, a method of adding a compound represented by the structural formula (A1) and / or (A2) synthesized separately to a non-aqueous electrolyte solution, a method of adding a compound represented by the general formula (A1) and / or (A2) synthesized separately to a solvent and then dissolving an electrolyte salt to form a non-aqueous electrolyte solution, a method of mixing a compound represented by the general formula (A1) and / or (A2) into battery components such as active materials, electrode plates, and separators described below to construct a battery element (battery element), and injecting a non-aqueous electrolyte solution to assemble an energy device such as a non-aqueous electrolyte secondary battery, a method of dissolving the compound represented by the general formula (A1) and / or (A2) in the non-aqueous electrolyte solution, a method of mixing a compound capable of generating the compound represented by the general formula (A1) and / or (A2) in a non-aqueous electrolyte solution or a non-aqueous electrolyte secondary battery in advance to obtain an electrolyte solution containing the compound represented by the general formula (A1) and / or (A2), etc. In the present invention, any method may be used.

[0063] The method for measuring the contents of the compounds represented by the general formulas (A1) and (A2) in the nonaqueous electrolyte solution and the nonaqueous electrolyte secondary battery is not particularly limited, and any known method can be used. Specifically, gas chromatography, liquid chromatography, １ H and １９ F nuclear magnetic resonance spectroscopy (hereinafter sometimes referred to as "NMR"), etc.

[0064] The reason why the effects of the present invention are achieved by a nonaqueous electrolyte solution containing compounds represented by general formulas (A1) and (A2) is speculated as follows: The cyclic fluorinated phosphate ester compound is reduced by accepting electrons on the negative electrode surface, and then reacts with the solvent reduction product to release fluorine ions and the cyclic phosphate ester compound. It is believed that these fluorine ions interact with lithium ions present on the negative electrode surface and in the electrolyte, thereby acting as a coating to protect the negative electrode surface. The cyclic phosphate ester compound has the property of undergoing ring-opening upon reaction with the solvent reduction decomposition product, and when this ring-opens, an intermolecular crosslinked compound is formed. This intermolecular crosslinked compound precipitates due to its low solubility and is believed to act as a coating to protect the negative electrode surface. When a specific compound such as a cyclic carbonate having a carbon-carbon unsaturated bond is contained in a nonaqueous electrolyte solution, an intermolecular crosslinked compound containing the phosphate ester compound and the specific compound as constituents is formed, which is believed to act as a suitable coating to protect the negative electrode surface. In this way, since a cyclic fluorinated phosphate ester can form different coating species from a single compound, it is presumed that the battery performance will be significantly improved compared to ordinary cyclic phosphorus compounds or chain-like fluorinated phosphorus compounds.

[0065] Among the compounds represented by general formulas (A1) and (A2), the compound represented by the following formula (A3) is a novel compound and is another embodiment of the present invention.

[0066] <1-1-2. Halogenated phosphate compound used in second embodiment> A nonaqueous electrolyte solution according to a second embodiment includes at least one compound selected from compounds represented by the following general formulas (B1) and (B2) (hereinafter, these compounds may be referred to as "halogenated phosphate ester used in the second embodiment"). In general formula (B1), X １ ' is a halogen atom, and Y is a divalent alkyl group having 2 to 4 carbon atoms which forms a ring together with a part of the halogenated phosphate ester, provided that a hydrogen atom on a carbon atom which forms the ring of Y may be substituted with a halogen atom or an organic group having 6 or less carbon atoms. In general formula (B2), X ２ ' and X ３ Each ' is independently a halogen atom, and Z represents a tetravalent alkyl group having 4 to 8 carbon atoms which forms a ring together with a part of the halogenated phosphate ester. However, a hydrogen atom on a carbon atom which forms a ring in Z may be substituted with a halogen atom or an organic group having 6 or less carbon atoms. First, the compound represented by general formula (B1) will be described.

[0067] <1-1-2-1. X １ '> X in general formula (B1) １ X' represents a halogen atom. Specific examples thereof include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Of these, a fluorine atom is preferred. １ By making ' a fluorine atom, when used in a non-aqueous electrolyte, the coating on the surface of the negative electrode is stabilized, and the capacity retention rate during repeated charge and discharge of the battery is improved.

[0068] <1-1-2-2. Y> In general formula (B1), Y represents a divalent alkyl group having 2 to 4 carbon atoms that form a ring together with a portion of the halogenated phosphate ester. Specific examples include the following structures. Here, * represents a bond to an oxygen atom of the halogenated phosphate ester. Among these, those having 2 or 3 carbon atoms that form a ring together with a portion of the halogenated phosphate ester are preferred in terms of industrial ease of handling in all steps, including production and storage of the halogenated phosphate ester compound used in the second embodiment, and production and use of the electrolyte solution. Of these, those having 3 carbon atoms that form a ring together with a portion of the halogenated phosphate ester are particularly preferred.

[0069] Here, the hydrogen atoms of the carbon atoms constituting the ring of Y may be substituted with halogen atoms or organic groups having 6 or less carbon atoms. Here, the organic group refers to a group containing at least one carbon atom.

[0070] Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom is preferred because it can more easily improve the capacity retention rate during repeated charge and discharge when used in an energy device, and it is preferred that at least one hydrogen atom of a carbon constituting a ring of Y is substituted with a fluorine atom.

[0071] Specific examples of the organic group having 6 or less carbon atoms include a hydrocarbon group and a group containing a heteroatom. Here, a hydrocarbon group is preferred in terms of ease of industrial handling in all steps, including production and storage of the halogenated phosphate ester used in this embodiment and production and use of the electrolyte solution, and a heteroatom-containing group is preferred in terms of improving compatibility with other compounds in the electrolyte solution and making it easier to adjust the properties of the electrolyte solution.

[0072] Specific examples of the hydrocarbon group include saturated hydrocarbon groups and hydrocarbon groups having an unsaturated bond, where a saturated hydrocarbon group is preferred because it can easily improve the capacity retention rate during repeated charge and discharge when used in an energy device.

[0073] Specific examples of saturated hydrocarbon groups include linear alkyl groups such as methyl, ethyl, n-propyl, n-butyl, and n-hexyl groups; branched alkyl groups such as isopropyl, isobutyl, sec-butyl, and neopentyl groups; and groups containing a partial cyclic structure such as cyclobutyl, cyclohexyl, and cyclopentylmethyl groups. Among these, those having 4 or less carbon atoms are preferred, more preferably 3 or less, and particularly preferably 2 or less, in order to more easily improve the repeated capacity retention rate when made into an energy device.

[0074] Specific examples of hydrocarbon groups having an unsaturated bond are not particularly limited as long as they have a structure in which the saturated hydrocarbon group has one or more carbon-carbon double or triple bonds, and specific examples include ethenyl, ethynyl, allyl, 2-propynyl, isopropenyl, 1-cyclohexenyl, and phenyl groups. Among these, those having 3 or less carbon atoms are preferred, ethenyl or allyl groups are more preferred, and ethenyl groups are particularly preferred, in order to more easily improve the capacity retention rate during repeated charge and discharge when used in an energy device.

[0075] Specific examples of the group containing a hetero atom include groups containing a cyano group, such as a cyano group, a cyanomethyl group, and a 2-cyanoethyl group; groups containing a halogen atom, such as a fluoromethyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a 2,2,3,3-tetrafluoropropyl group, and a 2-fluorophenyl group; groups containing an ether or thioether structure, such as a methoxy group, an ethoxy group, an iso-propoxy group, a tert-butoxy group, a phenyloxy group, a methoxymethyl group, an ethoxymethyl group, a methylthio group, an ethylthio group, a tert-butylthio group, a 3-(methylthio)propyl group, and a 2-(methylthio)butyl group; groups containing an amino group, such as a dimethylamino group, a diethylamino group, and a dimethylaminomethyl group; groups containing a carbonyl, ester, or carbonate structure, such as an acetyl group, a methoxycarbonyl group, a methylcarbonyloxy group, a methoxycarbonyloxy group, and a 1-(ethoxycarbonyl)ethyl group; groups containing a sulfonyl or sulfonate structure such as a methanesulfonyl group, a methanesulfonyloxy group, or a trifluoromethanesulfonyloxy group; groups containing an amide structure such as an acetamido group, an acetamidomethyl group, or a dimethylaminocarbonyl group; groups containing a nitro group such as a nitromethyl group, a 3-nitroisobutyl group, or a 2-nitrophenyl group; groups containing a silicon atom such as a trimethylsilyl group or a trimethylsilylethynyl group; groups containing a heterocycle such as a 2-furyl group, a 5-methyl-2-furyl group, a 3-pyrazolyl group, a 2-imidazolyl group, a 4-imidazolyl group, a 2-thiophenyl group, a 3-methyl-2-thiophenyl group, a 2-thiazolyl group, a 2-pyridyl group, a 3-pyridyl group, a 4-pyridyl group, a 2-quinolyl group, or a 5-nitro-2-furyl group; Among these, any one of a group containing a halogen atom, a group containing an ether structure, a group containing an ester or carbonate structure, and a group containing a silicon atom is preferred in that it is easier to improve the capacity retention rate during repeated charge and discharge when used in an energy device.

[0076] When a hydrogen atom on a carbon atom constituting a ring of Y is substituted with a halogen atom or an organic group having 6 or less carbon atoms, the number of substitutions is preferably 3 or less, more preferably 2 or less, and particularly preferably 1, in view of ease of industrial handling in all steps during production and storage of the halogenated phosphate ester compound of this embodiment and during production and use of the electrolyte solution.

[0077] Next, the compound represented by general formula (B2) will be described. <1-1-2-3. X ２ ' and X ３ '> X in general formula (B2) ２ ' and X ３ Each of X' independently represents a halogen atom. Specific examples thereof include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom is preferred in that it can more easily improve the capacity retention rate during repeated charge and discharge when used in an energy device. ２ ' and X ３ It is preferable that the halogenated phosphate ester compounds of the present embodiment are the same in that they are easily handled industrially in all steps, including production and storage of the halogenated phosphate ester compound, and production and use of the electrolyte solution.

[0078] <1-1-2-4. Z> In general formula (B1), Z represents a tetravalent alkyl group, and the number of carbon atoms that constitutes the ring together with a portion of the halogenated phosphate ester is 4 to 8, preferably 4 to 6, and more preferably 5. Specific examples include the following structures. Here, * represents a bond to an oxygen atom of the halogenated phosphate ester. Of these, a structure in which an oxygen atom is bonded to form a six-membered ring is preferred from the viewpoint of industrial ease of handling in all steps, including production and storage of the halogenated phosphate ester compound of this embodiment and production and use of the electrolyte solution.

[0079] Here, the hydrogen atom carried by the carbon atom constituting the ring in Z may be substituted with a halogen atom or an organic group having 6 or less carbon atoms. Specific and preferred examples thereof include specific examples of halogen atoms or organic groups having 6 or less carbon atoms which may be substituted with the hydrogen atom carried by the carbon atom constituting the ring in Y.

[0080] <1-1-2-5. Specific Examples> Specific examples of compounds represented by general formula (B1) or (B2) are shown below. Note that the halogenated phosphate ester compound used in the present invention is not limited to the specific examples shown below. In the following specific examples, "Ac" represents an acetyl group.

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089] Among these, the following compounds are preferred from the viewpoint of industrial ease of handling in all steps during the production and storage of the halogenated phosphate ester compound of the present embodiment, and during the production and use of the electrolyte solution.

[0090]

[0091]

[0092] Among these, the following compounds are more preferred from the viewpoints of stabilizing the coating on the negative electrode surface when used as an energy device and improving the capacity retention rate during repeated charge and discharge.

[0093]

[0094] The halogenated phosphate ester compounds of the second embodiment may be used alone or in any combination and ratio of two or more. The content of the halogenated phosphate ester compounds of the second embodiment is not particularly limited and may be any content as long as it does not significantly impair the effects of the present invention. However, the total content of the compounds represented by the general formulas (B1) and (B2) is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and particularly preferably 0.1% by mass or more, relative to the total amount of the nonaqueous electrolyte solution. By being within the above range, a suitable coating is formed on the negative electrode surface, and the effect of suppressing side reactions of the electrolyte solution components is exhibited, thereby significantly improving the cycle capacity retention rate during repeated charge and discharge.

[0095] On the other hand, the total content of the compounds represented by the general formulas (B1) and (B2) is preferably 30% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less, based on the total amount of the nonaqueous electrolyte solution. By being within this range, an excessive negative electrode coating is not formed, and lithium ion permeability can be ensured, thereby achieving suitable ranges for input / output characteristics and charge / discharge rate characteristics.

[0096] The method for producing the compounds represented by general formulas (B1) and (B2) is not particularly limited, and they can be produced by combining known methods. For example, there are methods using a cyclization reaction between a phosphoryl halide and a polyhydric alcohol, a cyclization reaction between a chain phosphate halide and a polyhydric alcohol, an oxidative halogenation reaction of a cyclic phosphonic acid, an oxidation reaction of a cyclic phosphonic acid halide, a halogenation reaction by substitution reaction of a cyclic phosphate ester, and a substitution reaction on a hydrocarbon group of a cyclic phosphate halide, an addition reaction, or a method of introducing or removing a substituent by elimination reaction. In addition, the halogen atom on the phosphorus of the cyclic phosphate halide can be replaced with a different halogen atom by substitution reaction. Furthermore, oxygen nucleophiles or carbon electrophiles derived from cyclic carbonates, etc., and LiPF ６ and a method for producing the same in an electrolyte by reacting a compound containing a phosphorus atom, such as the above, or a substance derived therefrom with itself.

[0097] The preparation of the non-aqueous electrolyte solution containing the compound represented by general formula (B1) and / or (B2) may be carried out by a known method, and is not particularly limited. For example, a method of adding a compound represented by the structural formula (B1) and / or (B2) synthesized separately to a non-aqueous electrolyte solution, a method of adding a compound represented by the general formula (B1) and / or (B2) synthesized separately to a solvent and then dissolving the electrolyte salt to form a non-aqueous electrolyte solution, a method of mixing a compound represented by the general formula (B1) and / or (B2) in battery components such as active materials, electrode plates, and separators described below to construct a battery element (battery element), and injecting a non-aqueous electrolyte solution to assemble an energy device such as a non-aqueous electrolyte secondary battery, a method of dissolving the compound represented by the general formula (B1) and / or (B2) in a non-aqueous electrolyte solution, a compound capable of generating the compound represented by the general formula (B1) and (B2) in a non-aqueous electrolyte solution or a non-aqueous electrolyte secondary battery in advance, and a method of obtaining an electrolyte solution containing the compound represented by the general formula (B1) and / or (B2), etc., may be mentioned. In the present invention, any method may be used.

[0098] The method for measuring the contents of the compounds represented by the general formulas (B1) and (B2) in the nonaqueous electrolyte solution and the nonaqueous electrolyte secondary battery is not particularly limited, and any known method can be used. Specifically, gas chromatography, liquid chromatography, １ H and １９ F nuclear magnetic resonance spectroscopy (hereinafter sometimes referred to as "NMR"), etc.

[0099] The reason why the effects of the present invention are achieved by a nonaqueous electrolyte containing a compound represented by general formula (B1) and / or (B2) is speculated as follows. It is speculated that the cyclic fluorinated phosphate ester compound reacts with the surface of the negative electrode active material containing silicon atoms, etc., to favorably modify the negative electrode surface. Furthermore, the cyclic fluorinated phosphate ester compound is reduced by accepting electrons on the negative electrode surface, and then reacts with the solvent reduction product to release fluorine ions and the cyclic phosphate ester compound. It is speculated that these fluorine ions interact with lithium ions present on the negative electrode surface and in the electrolyte, thereby acting as a protective coating on the negative electrode surface. The cyclic phosphate ester compound has the property of undergoing ring-opening upon reaction with the solvent reduction decomposition product, and when this crosslinked product is transferred between molecules, an intermolecularly crosslinked compound is formed. Due to its low solubility, this intermolecularly crosslinked compound precipitates and acts as a protective coating on the negative electrode surface. It is speculated that the cyclic fluorinated phosphate ester favorably modifies the negative electrode surface and can form different coating species from a single compound, resulting in significantly improved battery performance compared to conventional cyclic phosphorus compounds and chain-like fluorinated phosphorus compounds.

[0100] The first and second embodiments of the non-aqueous electrolyte solution described above may be used in combination, that is, the non-aqueous electrolyte solution in the first embodiment may contain the compound represented by the general formula (B1) and / or (B2) described above, and the non-aqueous electrolyte solution in the second embodiment may contain the compound represented by the general formula (A1) and / or (A2) described above. In these cases, the aspects and preferred conditions of each compound can be applied as described above.

[0101] <1-1-3. Specific Compound> The nonaqueous electrolyte solution according to one embodiment of the present invention (hereinafter, the nonaqueous electrolyte solution according to the first embodiment and the nonaqueous electrolyte solution according to the second embodiment will not be distinguished from each other, and will be collectively referred to as "nonaqueous electrolyte solution", "nonaqueous electrolyte solution of this embodiment", "nonaqueous electrolyte solution according to this embodiment", etc.) contains a cyclic carbonate having a fluorine atom, a cyclic carbonate having a carbon-carbon unsaturated bond, a difluorophosphate, FSO ２It is preferable that the composition contains at least one specific compound selected from the group consisting of a salt having the structure, a compound having an isocyanato group, a compound having a cyano group, a cyclic sulfonic acid ester, and a dicarboxylic acid complex salt.

[0102] It is believed that any of the specific compounds according to this embodiment react with the compound represented by general formula (A1) or (A2), or general formula (B1) or (B2), which is reduced on a reducing electrode among the multiple electrodes of an energy device, to cooperatively form a coating structure suitable for the electrode reaction. The present inventors speculate that this action and principle are not limited to the action and principle described below: (i) cyclic carbonate having a fluorine atom, (ii) cyclic carbonate having a carbon-carbon unsaturated bond, (iii) difluorophosphate, (iv) FSO ２ Regarding (v) a compound having an isocyanato group, (vi) a compound having a cyano group, (vii) a cyclic sulfonic acid ester, and (viii) a dicarboxylic acid complex salt, the nucleophilic species Nu formed on the surface of a reducing electrode by reduction of a compound represented by general formula (A1) or (A2), or general formula (B1) or (B2) － The estimated reaction mechanism is shown below.

[0103]

[0104] In the above reaction formula, Cat is a cation that constitutes the salt. １ is a divalent organic group containing fluorine, Q ２ is a divalent organic group containing a carbon-carbon unsaturated bond, Q ３ ~Q ５ is a monovalent organic group, Q ６ is a divalent organic group, Q ７ represents a single bond or a divalent organic group, and X represents a divalent organic group containing a central element of the complex. As shown in the reaction formula, each of the specific compounds contains a nucleophilic attack acceptor site, and it is presumed that each of the reactions shown serves as an initiation reaction, and further reacts with compound (A1) or (A2), or compound (B1) or (B2), to form a coating structure that favorably supports the electrode reaction.

[0105] The molecular weight of the specific compound is not particularly limited and may be any as long as it does not significantly impair the effects of the present invention, but is preferably 50 or more and 250 or less. Within this range, the solubility of the specific compound in the non-aqueous electrolyte solution is good, and the effect of addition can be fully exhibited. In addition, there is no particular limitation on the method for producing the specific compound, and it is possible to produce it by arbitrarily selecting a known method. In addition, commercially available products may be used. In addition, the specific compound may be contained alone in the non-aqueous electrolyte solution of this embodiment, or two or more types may be contained together in any combination and ratio.

[0106] <1-1-3-1. Cyclic Carbonates Having Fluorine Atoms> Among the specific compounds, the cyclic carbonates having fluorine atoms (hereinafter sometimes abbreviated as "fluorinated cyclic carbonates") are not particularly limited as long as they contain fluorine atoms, and any fluorinated cyclic carbonate can be used. Examples of fluorinated cyclic carbonates include derivatives of cyclic carbonates having an alkylene group having 2 to 6 carbon atoms, such as ethylene carbonate derivatives. Examples of ethylene carbonate derivatives include fluorinated products of ethylene carbonate or ethylene carbonate substituted with an alkyl group (e.g., an alkyl group having 1 to 4 carbon atoms), and among these, those having 1 to 8 fluorine atoms are preferred.

[0107] Specific examples include monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4-fluoro-4-methylethylene carbonate, 4,5-difluoro-4-methylethylene carbonate, 4-fluoro-5-methylethylene carbonate, 4,4-difluoro-5-methylethylene carbonate, 4-(fluoromethyl)-ethylene carbonate, 4-(difluoromethyl)-ethylene carbonate, 4-(trifluoromethyl)-ethylene carbonate, 4-(fluoromethyl)-4-fluoroethylene carbonate, 4-(fluoromethyl)-5-fluoroethylene carbonate, 4-fluoro-4,5-dimethylethylene carbonate, 4,5-difluoro-4,5-dimethylethylene carbonate, and 4,4-difluoro-5,5-dimethylethylene carbonate. Among these, at least one selected from the group consisting of monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, and 4,5-difluoro-4,5-dimethylethylene carbonate is more preferred in that it provides high ionic conductivity and favorably forms an interface protective coating.

[0108] The fluorinated cyclic carbonate may be used alone, or two or more types may be used in any combination and ratio. The content of the fluorinated cyclic carbonate is not particularly limited and may be any as long as it does not significantly impair the effects of the present invention. However, based on 100% by mass of the non-aqueous electrolyte solution, it is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and is usually 8% by mass or less, preferably 6% by mass or less, more preferably 5% by mass or less. Within this range, the non-aqueous electrolyte secondary battery is likely to exhibit sufficient cycle characteristics and high-temperature storage characteristics. Within this range, the non-aqueous electrolyte secondary battery is likely to exhibit sufficient cycle characteristics and high-temperature storage characteristics.

[0109] The fluorinated cyclic carbonate may be used as an auxiliary agent for the nonaqueous electrolyte solution or as a nonaqueous solvent. When used as a nonaqueous solvent, the content of the fluorinated cyclic carbonate is usually 8% by mass or more, preferably 10% by mass or more, more preferably 12% by mass or more, and usually 85% by mass or less, preferably 80% by mass or less, more preferably 75% by mass or less, based on 100% by mass of the nonaqueous electrolyte solution. Within this range, the nonaqueous electrolyte secondary battery is likely to exhibit a sufficient improvement in cycle characteristics, and a decrease in discharge capacity retention rate is likely to be avoided.

[0110] <1-1-3-2. Cyclic carbonate having a carbon-carbon unsaturated bond> Among the specific compounds, the cyclic carbonate having a carbon-carbon unsaturated bond (hereinafter sometimes abbreviated as "unsaturated cyclic carbonate") is not particularly limited as long as it is a cyclic carbonate having a carbon-carbon unsaturated bond, and any carbonate having a carbon-carbon unsaturated bond can be used. Note that cyclic carbonates having a substituent with an aromatic ring are also included in the cyclic carbonate having a carbon-carbon unsaturated bond. The method for producing the unsaturated cyclic carbonate is not particularly limited, and it can be produced by any known method selected.

[0111] Examples of unsaturated cyclic carbonates include vinylene carbonates, ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond, phenyl carbonates, vinyl carbonates, allyl carbonates, etc. Examples of vinylene carbonates include vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, phenyl vinylene carbonate, 4,5-diphenyl vinylene carbonate, vinyl vinylene carbonate, allyl vinylene carbonate, etc.

[0112] Specific examples of ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond include vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate, phenyl ethylene carbonate, 4,5-diphenyl ethylene carbonate, ethynyl ethylene carbonate, 4,5-diethynyl ethylene carbonate, etc. Among these, vinylene carbonates and ethylene carbonate substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond are preferred, and in particular, vinylene carbonate, 4,5-diphenyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, vinyl ethylene carbonate, or ethynyl ethylene carbonate are more preferably used because they form a stable interface protective coating.

[0113] The molecular weight of the unsaturated cyclic carbonate is not particularly limited and may be any as long as it does not significantly impair the effects of the present invention. The molecular weight of the unsaturated cyclic carbonate is usually 50 or more, preferably 80 or more, and usually 250 or less, preferably 150 or less. Within this range, the solubility of the unsaturated cyclic carbonate in the non-aqueous electrolyte solution is easily ensured, and the effects of the present invention are easily achieved. The unsaturated cyclic carbonate may be used alone, or two or more types may be used in any combination and ratio. The content of the unsaturated cyclic carbonate is also not particularly limited and may be any as long as it does not significantly impair the effects of the present invention. The content of the unsaturated cyclic carbonate is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more, based on 100% by mass of the non-aqueous electrolyte solution. It is usually 10% by mass or less, preferably 8% by mass or less, and more preferably 5% by mass or less. Within the above range, the non-aqueous electrolyte secondary battery is likely to exhibit sufficient high-temperature storage characteristics and improved cycle characteristics.

[0114] <1-1-3-3. Difluorophosphate> Among the specific compounds, the difluorophosphate is not particularly limited as long as it is a salt containing a difluorophosphate anion as a constituent element, and any difluorophosphate can be used. Examples of difluorophosphates include lithium difluorophosphate (LiPO２ F ２ Examples of the difluorophosphate include sodium difluorophosphate, potassium difluorophosphate, and ammonium difluorophosphate. Among these, lithium difluorophosphate is preferred, and is more preferably used because it can contribute to the formation of a stable film-like structure.

[0115] The content of difluorophosphate is not particularly limited and may be any content as long as it does not significantly impair the effects of the present invention, but is preferably 0.001% by mass or more and 2.0% by mass or less relative to the nonaqueous electrolyte solution of this embodiment. When the content of difluorophosphate is above this lower limit, a sufficient effect of improving the cycle characteristics of the nonaqueous electrolyte secondary battery can be achieved. Furthermore, when the content is below this upper limit, an increase in the manufacturing cost of the nonaqueous electrolyte secondary battery can be avoided. The content of difluorophosphate is more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and more preferably 1.5% by mass or less, even more preferably 1.2% by mass or less, and particularly preferably 1.1% by mass or less.

[0116] <1-1-3-4. F.S.O. ２ Salts having the structure FSO ２ Examples of salts having the structure include FSO ２ There are no particular limitations on the salt as long as it has as a component an anion having the structure FSO ２ A salt having the structure FSO can be used. ２ Examples of salts having the structure include lithium fluorosulfonate (hereinafter referred to as FSO ３ Li), sodium fluorosulfonate, potassium fluorosulfonate, ammonium fluorosulfonate, (FSO ２ ) ２ NLi, (FSO ２ ) (CF ３ SO ２ ) NLi, (FSO ２ ) (CF ３ CF ２ SO ２ )NLi, etc. Among them, lithium fluorosulfonate and (FSO ２ )２ NLi is preferred, and is more preferably used since it can contribute to the formation of a stable film-like structure.

[0117] FSO ２ The content of the salt having the structure FSO is not particularly limited and may be any amount as long as it does not significantly impair the effects of the present invention, but is preferably 0.001 mass % or more and 8.0 mass % or less relative to the nonaqueous electrolyte solution of this embodiment. ２ When the content of the salt having the FSO structure is equal to or greater than this lower limit, the cycle characteristics of the non-aqueous electrolyte secondary battery can be sufficiently improved. When the content is equal to or less than this upper limit, an increase in the manufacturing cost of the non-aqueous electrolyte secondary battery can be avoided. ２ The salt having the structure FSO ３ In the case of Li, the content is more preferably 0.01 mass% or more, even more preferably 0.1 mass% or more, particularly preferably 0.2 mass% or more, and more preferably 3.0 mass% or less, even more preferably 2.5 mass% or less, particularly preferably 2.0 mass% or less.

[0118] <1-1-3-5. Compound Having an Isocyanato Group> Among the specific compounds, the compound having an isocyanato group (hereinafter sometimes abbreviated as "isocyanate") is not particularly limited, and any isocyanate can be used. Examples of the isocyanate include monoisocyanates, diisocyanates, triisocyanates, etc.

[0119] Specific examples of monoisocyanates include isocyanatomethane, isocyanatoethane, 1-isocyanatopropane, 1-isocyanatobutane, 1-isocyanatopentane, 1-isocyanatohexane, 1-isocyanatoheptane, 1-isocyanatooctane, 1-isocyanatononane, 1-isocyanatodecane, isocyanatocyclohexane, methoxycarbonyl isocyanate, ethoxycarbonyl isocyanate, propoxycarbonyl isocyanate, butoxycarbonyl isocyanate, methoxysulfonyl isocyanate, ethoxysulfonyl isocyanate, propoxysulfonyl isocyanate, butoxysulfonyl isocyanate, and fluorosulfonyl isocyanate.

[0120] Specific examples of diisocyanates include 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatohexane, 1,7-diisocyanatoheptane, 1,8-diisocyanatooctane, 1,9-diisocyanatononane, 1,10-diisocyanatodecane, 1,3-diisocyanatopropene, 1,4-diisocyanato-2-butene, 1,4-diisocyanato-2-fluorobutane, 1,4-diisocyanato-2-methyl ... Cyanato-2,3-difluorobutane, 1,5-diisocyanato-2-pentene, 1,5-diisocyanato-2-methylpentane, 1,6-diisocyanato-2-hexene, 1,6-diisocyanato-3-hexene, 1,6-diisocyanato-3-fluorohexane, 1,6-diisocyanato-3,4-difluorohexane, toluene diisocyanate, xylene diisocyanate, tolylene diisocyanate, 1,2-bis(2-methyl-2-isocyanato) (Isocyanatomethyl)cyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, dicyclohexylmethane-1,1'-diisocyanate, dicyclohexylmethane-2,2'-diisocyanate, dicyclohexylmethane-3 ,3'-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, isophorone diisocyanate, bicyclo[2.2.1]heptane-2,5-diylbis(methyl isocyanate), bicyclo[2.2.1]heptane-2,6-diylbis(methyl isocyanate), 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, etc.

[0121] Specific examples of triisocyanates include 1,6,11-triisocyanatoundecane, 4-isocyanatomethyl-1,8-octamethylene diisocyanate, 1,3,5-triisocyanatomethylbenzene, 1,3,5-tris(6-isocyanatohex-1-yl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 4-(isocyanatomethyl)octamethylene diisocyanate.

[0122] Among these, 1,6-diisocyanatohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,3,5-tris(6-isocyanatohex-1-yl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,4,4-trimethylhexamethylene diisocyanate, and 2,2,4-trimethylhexamethylene diisocyanate are preferred because they are easily available industrially and can keep the production cost of the electrolyte solution low, and also from a technical viewpoint, can contribute to the formation of a stable coating structure, and are therefore more preferably used.

[0123] The isocyanate content is not particularly limited and may be any content as long as it does not significantly impair the effects of the present invention. However, it is preferably 0.001% by mass or more and 1.0% by mass or less relative to the nonaqueous electrolyte solution of this embodiment. When the isocyanate content is above this lower limit, a sufficient effect of improving the cycle characteristics of the nonaqueous electrolyte secondary battery can be achieved. Furthermore, when the isocyanate content is below this upper limit, an increase in the initial resistance of the nonaqueous electrolyte secondary battery can be avoided. The isocyanate content is more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and more preferably 0.8% by mass or less, even more preferably 0.7% by mass or less, and particularly preferably 0.6% by mass or less.

[0124] <1-1-3-6. Compound Having a Cyano Group> Among the specific compounds, the compound having a cyano group (hereinafter sometimes abbreviated as "nitrile") is not particularly limited, and any nitrile can be used. Examples of the nitrile include mononitriles and dinitriles. Specific examples of mononitriles include acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, lauronitrile, 2-methylbutyronitrile, trimethylacetonitrile, hexanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, acrylonitrile, methacrylonitrile, crotononitrile, 3-methylcrotononitrile, 2-methyl-2-butenenitrile, 2-pentenenitrile, 2-methyl-2-pentenenitrile, 3-methyl-2-pentenenitrile, 2-hexenenitrile, fluoroacetonitrile, difluoroacetonitrile, trifluoroacetonitrile, 2-fluoropropionitrile, 3-fluoropropionitrile, 2,2-difluoropropionitrile, 2,3-difluoropropionitrile, 3,3-difluoropropionitrile, 2,2,3-trifluoropropionitrile, and 3,3 , 3-trifluoropropionitrile, 3,3'-oxydipropionitrile, 3,3'-thiodipropionitrile, 1,2,3-propanetricarbonitrile, 1,3,5-pentanetricarbonitrile, pentafluoropropionitrile, and the like.Specific examples of dinitriles include malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelanitrile, sebaconitrile, undecanedinitrile, dodecanedinitrile, methylmalononitrile, ethylmalononitrile, isopropylmalononitrile, tert-butylmalononitrile, methylsuccinonitrile, 2,2-dimethylsuccinonitrile, 2,3-dimethylsuccinonitrile, 2,3,3-trimethylsuccinonitrile, 2,2,3,3-tetramethylsuccinonitrile, 2,3-diethyl-2,3-dimethylsuccinonitrile, 2,2-diethyl-3,3-dimethylsuccinonitrile, bicyclohexyl-1,1-dicarbonitrile, bicyclohexyl-2,2-dicarbonitrile, bicyclohexyl-3,3-dicarbonitrile, and 2,5-dimethyl-2,5-hexane. Dicarbonitrile, 2,3-diisobutyl-2,3-dimethylsuccinonitrile, 2,2-diisobutyl-3,3-dimethylsuccinonitrile, 2-methylglutaronitrile, 2,3-dimethylglutaronitrile, 2,4-dimethylglutaronitrile, 2,2,3,3-tetramethylglutaronitrile, 2,2,4,4-tetramethylglutaronitrile, 2,2,3,4-tetramethylglutaronitrile, 2,3,3,4 -tetramethylglutaronitrile, maleonitrile, fumaronitrile, 1,4-dicyanopentane, 2,6-dicyanoheptane, 2,7-dicyanooctane, 2,8-dicyanononane, 1,6-dicyanodecane, 1,2-dicyanobenzene, 1,3-dicyanobenzene, 1,4-dicyanobenzene, 3,3'-(ethylenedioxy)dipropionitrile, 3,3'-(ethylenedithio)dipropionitrile, and the like.

[0125] Among these, dinitriles such as malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimelonitrile, suberonitrile, azelanitrile, sebaconitrile, undecanedinitrile, and dodecanedinitrile can contribute to the formation of a stable film-like structure, and are therefore more preferably used.

[0126] The nitrile content is not particularly limited and may be any content as long as it does not significantly impair the effects of the present invention. However, it is preferably 0.001% by mass or more and 5.0% by mass or less relative to the nonaqueous electrolyte solution of this embodiment. When the nitrile content is above this lower limit, a sufficient effect of improving the cycle characteristics of the nonaqueous electrolyte secondary battery can be achieved. Furthermore, when the nitrile content is below this upper limit, an increase in the initial resistance of the nonaqueous electrolyte secondary battery can be avoided, and deterioration of the rate characteristics can be suppressed. The nitrile content is more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and more preferably 4.0% by mass or less, even more preferably 3.0% by mass or less, and particularly preferably 2.5% by mass or less.

[0127] <1-1-3-7. Cyclic sulfonate ester> Among the specific compounds, the cyclic sulfonate ester is not particularly limited, and any cyclic sulfonate ester can be used. Examples of the cyclic sulfonate ester include saturated cyclic sulfonate esters and unsaturated cyclic sulfonate esters.

[0128] Specific examples of the saturated cyclic sulfonic acid ester include 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, 1-methyl-1,3-propane sultone, 2-methyl-1,3-propane sultone, 3-methyl-1,3-propane sultone, 1,4-butane sultone, 1-fluoro-1,4-butane sultone, 2-fluoro-1,4-butane sultone, 3-fluoro-1,4-butane sultone, 4-fluoro-1,4-butane sultone, 1-methyl-1,4-butane sultone, 2-methyl-1,4-butane sultone, 3-methyl-1,4-butane sultone, 4-methyl-1,4-butane sultone, methylenemethane disulfonate, and ethylenemethane disulfonate.

[0129] Specific examples of the unsaturated cyclic sulfonic acid ester include 1-propene-1,3-sultone, 2-propene-1,3-sultone, 1-fluoro-1-propene-1,3-sultone, 2-fluoro-1-propene-1,3-sultone, 3-fluoro-1-propene-1,3-sultone, 1-fluoro-2-propene-1,3-sultone, 2-fluoro-2-propene-1,3-sultone, 3-fluoro-2-propene-1,3-sultone, 1-methyl-1-propene-1,3-sultone, 2-methyl- 1-propene-1,3-sultone, 3-methyl-1-propene-1,3-sultone, 1-methyl-2-propene-1,3-sultone, 2-methyl-2-propene-1,3-sultone, 3-methyl-2-propene-1,3-sultone, 1-butene-1,4-sultone, 2-butene-1,4-sultone, 3-butene-1,4-sultone, 1-fluoro-1-butene-1,4-sultone, 2-fluoro-1-butene-1,4-sultone, 3-fluoro-1-butene-1,4-sultone, 4-fluoro-1- butene-1,4-sultone, 1-fluoro-2-butene-1,4-sultone, 2-fluoro-2-butene-1,4-sultone, 3-fluoro-2-butene-1,4-sultone, 4-fluoro-2-butene-1,4-sultone, 1-fluoro-3-butene-1,4-sultone, 2-fluoro-3-butene-1,4-sultone, 3-fluoro-3-butene-1,4-sultone, 4-fluoro-3-butene-1,4-sultone, 1-methyl-1-butene-1,4-sultone, 2-methyl-1-butene-1, 4-sultone, 3-methyl-1-butene-1,4-sultone, 4-methyl-1-butene-1,4-sultone, 1-methyl-2-butene-1,4-sultone, 2-methyl-2-butene-1,4-sultone, 3-methyl-2-butene-1,4-sultone, 4-methyl-2-butene-1,4-sultone, 1-methyl-3-butene-1,4-sultone, 2-methyl-3-butene-1,4-sultone, 3-methyl-3-butene-1,4-sultone, 4-methyl-3-butene-1,4-sultone, and the like.

[0130] Among the above, 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, methylenemethane disulfonate, ethylenemethane disulfonate, and 1-propene-1,3-sultone are more preferably used because they are easily available and can contribute to the formation of a stable coating structure.

[0131] The content of the cyclic sulfonate ester is not particularly limited and may be any content as long as it does not significantly impair the effects of the present invention. However, it is preferably 0.001% by mass or more and 3.0% by mass or less relative to 100% by mass of the nonaqueous electrolyte solution of this embodiment. When the content of the cyclic sulfonate ester is above this lower limit, a sufficient effect of improving the cycle characteristics of the energy device can be achieved. Furthermore, when the content is below this upper limit, an increase in the manufacturing cost of the energy device can be avoided. The content of the cyclic sulfonate ester is more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and more preferably 5.0% by mass or less, even more preferably 3.0% by mass or less, and particularly preferably 2.0% by mass or less.

[0132] <1-1-3-8. Dicarboxylic acid complex salt> Among the specific compounds, the dicarboxylic acid complex salt is not particularly limited, and any dicarboxylic acid complex salt can be used. Examples of the dicarboxylic acid complex salt include dicarboxylic acid complex salts in which the central element of the complex is boron, dicarboxylic acid complex salts in which the central element of the complex is phosphorus, etc.

[0133] Specific examples of dicarboxylic acid complex salts in which the central element of the complex is boron include lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium bis(malonato)borate, lithium difluoro(malonato)borate, lithium bis(methylmalonato)borate, lithium difluoro(methylmalonato)borate, lithium bis(dimethylmalonato)borate, and lithium difluoro(dimethylmalonato)borate.

[0134] Specific examples of dicarboxylic acid complex salts in which the central element of the complex is phosphorus include lithium tris(oxalato)phosphate, lithium difluorobis(oxalato)phosphate, lithium tetrafluoro(oxalato)phosphate, lithium tris(malonato)phosphate, lithium difluorobis(malonato)phosphate, lithium tetrafluoro(malonato)phosphate, lithium tris(methylmalonato)phosphate, lithium difluorobis(methylmalonato)phosphate, lithium tetrafluoro(methylmalonato)phosphate, lithium tris(dimethylmalonato)phosphate, lithium difluorobis(dimethylmalonato)phosphate, and lithium tetrafluoro(dimethylmalonato)phosphate.

[0135] Among these, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tris(oxalato)phosphate, lithium difluorobis(oxalato)phosphate, and lithium tetrafluoro(oxalato)phosphate are more preferably used because of their ease of availability and their ability to contribute to the formation of a stable coating structure.

[0136] The content of the dicarboxylic acid complex salt is not particularly limited and may be any content as long as it does not significantly impair the effects of the present invention. However, it is preferably 0.001% by mass or more and 2.5% by mass or less relative to the nonaqueous electrolyte solution of this embodiment. When the content of the dicarboxylic acid complex salt is above this lower limit, the nonaqueous electrolyte secondary battery can be provided with a sufficient improvement in cycle characteristics. When the content is below this upper limit, an increase in the manufacturing cost of the nonaqueous electrolyte secondary battery can be avoided, and volume expansion of the nonaqueous electrolyte secondary battery due to gas generation can be avoided. The content of the dicarboxylic acid complex salt is more preferably 0.01% by mass or more, even more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and more preferably 5.0% by mass or less, even more preferably 3.0% by mass or less, and particularly preferably 2.0% by mass or less.

[0137] <1-1-3-9. Preferable specific compounds> Examples of the specific compounds include cyclic carbonates having a fluorine atom, cyclic carbonates having a carbon-carbon unsaturated bond, difluorophosphates, and FSO ２ It is preferable that the compound contains at least one compound selected from the group consisting of a salt having a structure, a compound having an isocyanato group, a cyclic sulfonate ester, and a dicarboxylic acid complex salt, and among these, a cyclic carbonate having a carbon-carbon unsaturated bond, a difluorophosphate, or FSO ２ It is more preferable that the compound contains a salt having the structure. Specific specific compounds include monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, vinylene carbonate, vinylethylene carbonate, ethynylethylene carbonate, lithium difluorophosphate, lithium fluorosulfonate, (FSO ２ ) ２ It is preferred that the fluorocarbon polymer contains NLi, 1,6-diisocyanatohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,3-propane sultone, methylenemethane disulfonate, 1-propene-1,3-sultone, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tris(oxalato)phosphate, lithium difluorobis(oxalato)phosphate, or lithium tetrafluoro(oxalato)phosphate, and it is also preferred that the fluorocarbon polymer contains monofluoroethylene carbonate, vinylene carbonate, vinylethylene carbonate, lithium difluorophosphate, lithium fluorosulfonate, (FSO ２ ) ２ It is more preferable that the compound contains NLi, 1,6-diisocyanatohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,3-propane sultone, methylenemethane disulfonate, 1-propene-1,3-sultone, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, or lithium difluorobis(oxalato)phosphate. It is also preferable that the compound contains a plurality of types of the above-mentioned specific compounds, and it is more preferable that the compound contains both a cyclic carbonate having a carbon-carbon unsaturated bond and a difluorophosphate.

[0138] <1-1-4. Electrolyte> The nonaqueous electrolyte solution according to this embodiment, like a general nonaqueous electrolyte solution, usually contains an electrolyte as a component. The electrolyte preferably contains one or more lithium salts. The lithium salt is not particularly limited as long as it is known to be used as an electrolyte, and any lithium salt can be used, and specific examples thereof include the following.

[0139] For example, LiBF ４ , LiClO ４ , LiAlF ４ , LiPF ６ , LiSbF ６ , LiTaF ６ , LiWOF ５ , LiWF ７ inorganic lithium halide salts such as; HCO ２ Li, C.H. ３ CO ２ Li, C.H. ２ FCO ２ Li, CHF ２ CO ２ Li, CF ３ CO ２ Li, CF ３ CH ２ CO ２ Li, CF ３ CF ２ CO ２ Li, CF ３ CF ２ CF ２ CO ２ Li, CF ３ CF ２ CF ２ CF ２ CO ２ Lithium carboxylates such as Li; ３ SO ３ Li, C.H. ２ FSO ３ Li, CHF ２ SO ３ Li, CF ３ SO ３ Li, CF ３ CF ２ SO ３ Li, CF ３ CF ２ CF２ SO ３ Li, CF ３ CF ２ CF ２ CF ２ SO ３ FSO by Li et al. ３ Lithium sulfonate salts other than Li: lithium sulfate salts such as methyl lithium sulfate, ethyl lithium sulfate, 2-propynyl lithium sulfate, 1-methyl-2-propynyl lithium sulfate, 1,1-dimethyl-2-propynyl lithium sulfate, 2,2,2-trifluoroethyl lithium sulfate, and dilithium ethylene disulfate; LiN(FCO ２ ) ２ , LiN(CF ３ SO ２ ) ２ , LiN(C ２ F ５ SO ２ ) ２ , lithium cyclic 1,2-perfluoroethane disulfonylimide, lithium cyclic 1,3-perfluoropropane disulfonylimide, LiN(CF ３ SO ２ ) (C ４ F ９ SO ２ ) and other FSOs ２ Lithium imide salts other than salts having the structure: LiC(FSO ２ ) ３ , LiC(CF ３ SO ２ ) ３ , LiC(C ２ F ５ SO ２ ) ３ Lithium methide salts such as lithium difluorooxalatoborate, lithium tetrafluorooxalatophosphate, and lithium tris(oxalato)phosphate; and other lithium oxalate salts such as LiPF ４ (CF ３ ) ２ , LiPF ４ (C ２ F ５ ) ２ , LiPF ４ (CF ３ SO ２ )２ , LiPF ４ (C ２ F ５ SO ２ ) ２ , LiBF ３ CF ３ , LiBF ３ C ２ F ５ , LiBF ３ C ３ F ７ , LiBF ２ (CF ３ ) ２ , LiBF ２ (C ２ F ５ ) ２ , LiBF ２ (CF ３ SO ２ ) ２ , LiBF ２ (C ２ F ５ SO ２ ) ２ fluorine-containing organic lithium salts such as:

[0140] Among these lithium salts, those selected from inorganic lithium salts, lithium sulfonate salts, lithium imide salts, and lithium oxalate salts are preferred from the viewpoint of further enhancing the effects of improving input / output characteristics after durability tests such as high-temperature storage tests and cycle tests, charge / discharge rate characteristics, and impedance characteristics. ４ , LiPF ６ , LiSbF ６ , LiTaF ６ , C.F. ３ SO ３ Li, LiN(CF ３ SO ２ ) ２ , LiN(C ２ F ５ SO ２ ) ２ , lithium cyclic 1,2-perfluoroethane disulfonylimide, lithium cyclic 1,3-perfluoropropane disulfonylimide, LiC(FSO ２ ) ３ , LiC(CF ３ SO ２) ３ , LiC(C ２ F ５ SO ２ ) ３ Lithium difluorooxalatoborate, lithium tetrafluorooxalatophosphate, and lithium tris(oxalato)phosphate are particularly preferred because they have the effect of improving input / output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, cycle characteristics, and the like.

[0141] The total concentration of these electrolytes in the non-aqueous electrolyte solution is not particularly limited, but is usually 8% by mass or more, preferably 8.5% by mass or more, and more preferably 9% by mass or more, when the entire non-aqueous electrolyte solution is taken as 100% by mass. The upper limit is usually 18% by mass or less, preferably 17% by mass or less, and more preferably 16% by mass or less. If the total concentration of the electrolytes is within the above range, the electrical conductivity is suitable for battery operation, which is preferable.

[0142] These electrolytes may be used alone, in combination of two or more, or in combination with a specific compound. A preferred example of a combination is LiPF ６ and LiBF ４ , LiPF ６ and LiPO ２ F ２ , LiPF ６ and FSO ３ Li, LiPF ６ and LiN (FSO ２ ) ２ , LiPF ６ and LiN (CF ３ SO ２ ) ２ , LiPF ６ and lithium bis(oxalato)borate, LiPF ６ and lithium tetrafluorooxalatophosphate, LiPF ６ and lithium difluorobis(oxalato)phosphate, LiPF ６ and LiBF ４ and LiPO ２ F ２ , LiPF ６ and LiBF ４ and FSO ３ Li, LiPF６ and LiPO ２ F ２ and FSO ３ Li, LiPF ６ and LiPO ２ F ２ and lithium bis(oxalato)borate, LiPF ６ and LiPO ２ F ２ and lithium difluorobis(oxalato)phosphate, LiPF ６ and LiPO ２ F ２ and LiN (FSO ２ ) ２ , LiPF ６ and LiPO ２ F ２ and LiN (CF ３ SO ２ ) ２ , LiPF ６ and FSO ３ Li and lithium bis(oxalato)borate, or LiPF ６ and FSO ３ The combined use of Li and lithium difluorobis(oxalato)phosphate has the effect of improving input / output characteristics, high-temperature storage characteristics, and cycle characteristics. ６ The content of LiBF in the non-aqueous electrolyte solution is preferably 7% by mass or more, more preferably 7.5% by mass or more, even more preferably 8% by mass or more, and preferably 16% by mass or less, more preferably 15% by mass or less, even more preferably 14% by mass or less. ４ , LiPO ２ F ２ , FSO ３ Li, LiN (FSO ２ ) ２ LiN (CF ３ SO ２ ) ２ The content of LiPF , lithium bis(oxalato)borate, or lithium difluorobis(oxalato)phosphate in the non-aqueous electrolyte is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less. ６When the concentration of is within the above preferred range, the total ion content and viscosity of the non-aqueous electrolyte are appropriately balanced, so that the internal impedance of the battery is low without excessively decreasing the ionic conductivity, and LiPF ６ The effects of improving input / output characteristics, cycle characteristics, and storage characteristics due to the blending of the above are more likely to be realized.

[0143] Here, the preparation of the non-aqueous electrolyte solution containing the electrolyte material may be carried out by a known method, and is not particularly limited. For example, a method of adding the electrolyte material synthesized separately to a non-aqueous electrolyte solution, a method of mixing the electrolyte material into battery components such as the active material and electrode plates described below to construct a battery element (battery element), and dissolving the electrolyte material in the non-aqueous electrolyte solution when assembling the battery by injecting the non-aqueous electrolyte solution, a method of allowing water to coexist in battery components such as the active material, electrode plates, and separators, and generating other electrolyte materials in the system when assembling a non-aqueous electrolyte secondary battery using a non-aqueous electrolyte solution containing the electrolyte material, etc. In this embodiment, any method may be used.

[0144] The method for measuring the content of each electrolyte in the nonaqueous electrolyte solution and the nonaqueous electrolyte secondary battery is not particularly limited, and any known method can be used. １９ F nuclear magnetic resonance spectroscopy (hereinafter sometimes referred to as "NMR"), etc.

[0145] <1-1-5. Nonaqueous Solvent> The nonaqueous electrolyte solution according to one embodiment of the present invention, like a general nonaqueous electrolyte solution, typically contains, as its main component, a nonaqueous solvent that dissolves the above-described electrolyte. There are no particular limitations on the nonaqueous solvent used here, and known organic solvents can be used. The organic solvent preferably contains at least one organic solvent (compound) selected from the group consisting of saturated cyclic carbonates, chain carbonates, chain carboxylic acid esters, cyclic carboxylic acid esters, ether-based compounds, and sulfone-based compounds, but is not particularly limited thereto. These organic solvents can be used alone or in combination of two or more. In one embodiment of the present invention, the nonaqueous electrolyte solution preferably contains one or more selected from the group consisting of cyclic carbonates, chain carbonates, and chain esters.

[0146] <1-1-5-1. Saturated Cyclic Carbonates> Examples of saturated cyclic carbonates include those having an alkylene group having 2 to 4 carbon atoms. Specific examples of saturated cyclic carbonates having 2 to 4 carbon atoms include ethylene carbonate, propylene carbonate, and butylene carbonate. Among these, ethylene carbonate and propylene carbonate are preferred from the viewpoint of improving battery characteristics due to an improved degree of lithium ion dissociation. One type of saturated cyclic carbonate may be used alone, or two or more types may be used in any combination and ratio.

[0147] The content of the saturated cyclic carbonate is not particularly limited and may be any content as long as it does not significantly impair the effects of the present invention. However, when one type is used alone, the lower limit of the content is usually 3 vol% or more, preferably 5 vol% or more, based on 100 vol% of the nonaqueous solvent. By setting it within this range, a decrease in electrical conductivity due to a decrease in the dielectric constant of the nonaqueous electrolyte solution can be avoided, and the large current discharge characteristics, stability to the negative electrode, and cycle characteristics of the nonaqueous electrolyte secondary battery can be easily set to a good range. The upper limit is usually 90 vol% or less, preferably 85 vol% or less, and more preferably 80 vol% or less. By setting it within this range, the viscosity of the nonaqueous electrolyte solution can be set to an appropriate range, a decrease in ionic conductivity can be suppressed, and thus the input / output characteristics of the nonaqueous electrolyte secondary battery can be further improved, and durability such as cycle characteristics and storage characteristics can be further improved, which is preferable.

[0148] Furthermore, any combination of two or more saturated cyclic carbonates can be used. 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, more preferably 95:5 to 50:50. Furthermore, the lower limit of the amount of propylene carbonate in the total nonaqueous solvent is usually 1% by volume or more, preferably 2% by volume or more, more preferably 3% by volume or more. The upper limit is usually 30% by volume or less, preferably 25% by volume or less, more preferably 20% by volume or less. A propylene carbonate content within this range is preferred because it provides even better low-temperature properties.

[0149] <1-1-5-2. Chain Carbonates> Chain carbonates having 3 to 7 carbon atoms are preferred. Specific examples of chain carbonates having 3 to 7 carbon atoms include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate, methyl-n-propyl carbonate, n-butyl methyl carbonate, isobutyl methyl carbonate, t-butyl methyl carbonate, ethyl-n-propyl carbonate, n-butyl ethyl carbonate, isobutyl ethyl carbonate, and t-butyl ethyl carbonate. Of these, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate, and methyl-n-propyl carbonate are preferred, and dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate are particularly preferred.

[0150] Furthermore, chain carbonates having fluorine atoms (hereinafter sometimes abbreviated as "fluorinated chain carbonate") can also be suitably used. The number of fluorine atoms in the fluorinated chain carbonate is not particularly limited as long as it is 1 or more, but is usually 6 or less, preferably 4 or less. When the fluorinated chain carbonate has multiple fluorine atoms, they may be bonded to the same carbon or different carbons. Examples of fluorinated chain carbonates include fluorinated dimethyl carbonate derivatives, fluorinated ethyl methyl carbonate derivatives, and fluorinated diethyl carbonate derivatives.

[0151] Examples of fluorinated dimethyl carbonate derivatives include fluoromethyl methyl carbonate, difluoromethyl methyl carbonate, trifluoromethyl methyl carbonate, bis(fluoromethyl)carbonate, bis(difluoro)methyl carbonate, bis(trifluoromethyl)carbonate, etc. Examples of fluorinated ethyl methyl carbonate derivatives include 2-fluoroethyl methyl carbonate, ethyl fluoromethyl carbonate, 2,2-difluoroethyl methyl carbonate, 2-fluoroethyl fluoromethyl carbonate, ethyl difluoromethyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, 2,2-difluoroethyl fluoromethyl carbonate, 2-fluoroethyl difluoromethyl carbonate, ethyl trifluoromethyl carbonate, etc.

[0152] Examples of fluorinated diethyl carbonate derivatives include ethyl (2-fluoroethyl) carbonate, ethyl (2,2-difluoroethyl) carbonate, bis (2-fluoroethyl) carbonate, ethyl (2,2,2-trifluoroethyl) carbonate, 2,2-difluoroethyl-2'-fluoroethyl carbonate, bis (2,2-difluoroethyl) carbonate, 2,2,2-trifluoroethyl-2'-fluoroethyl carbonate, 2,2,2-trifluoroethyl-2',2'-difluoroethyl carbonate, bis (2,2,2-trifluoroethyl) carbonate, etc. The chain carbonates may be used alone or in any combination and ratio of two or more.

[0153] The content of the chain carbonate is not particularly limited, but is usually 15% by volume or more, preferably 20% by volume or more, and more preferably 25% by volume or more, based on 100% by volume of the nonaqueous solvent. It is also usually 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. By setting the content of the chain carbonate within the above range, the viscosity of the nonaqueous electrolyte solution is kept within an appropriate range, a decrease in ionic conductivity is suppressed, and the input / output characteristics and charge / discharge rate characteristics of the nonaqueous electrolyte secondary battery are easily maintained within good ranges. Furthermore, a decrease in electrical conductivity due to a decrease in the dielectric constant of the nonaqueous electrolyte solution is avoided, and the input / output characteristics and charge / discharge rate characteristics of the nonaqueous electrolyte secondary battery are easily maintained within good ranges.

[0154] Furthermore, by combining a specific chain carbonate with a specific content of ethylene carbonate, battery performance can be significantly improved. For example, when dimethyl carbonate and ethyl methyl carbonate are selected as the specific chain carbonate, the content of ethylene carbonate is not particularly limited and can be any content as long as it does not significantly impair the effects of the present invention, but is usually 15% by volume or more, preferably 20% by volume or more, and usually 45% by volume or less, preferably 40% by volume or less. The content of dimethyl carbonate is usually 20% by volume or more, preferably 30% by volume or more, and usually 50% by volume or less, preferably 45% by volume or less. The content of ethyl methyl carbonate is usually 20% by volume or more, preferably 30% by volume or more, and usually 50% by volume or less, preferably 45% by volume or less. By setting the content within the above ranges, the low-temperature deposition temperature of the electrolyte is lowered, and the viscosity of the nonaqueous electrolyte is also lowered, improving ionic conductivity and allowing high input / output even at low temperatures.

[0155] <1-1-5-3. Chain Carboxylic Acid Ester> Examples of chain carboxylic acid esters include those having a total carbon number in the structural formula of 3 to 7. Specific examples include methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, isopropyl propionate, n-butyl propionate, isobutyl propionate, t-butyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, n-propyl isobutyrate, and isopropyl isobutyrate.

[0156] Among these, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, isopropyl propionate, methyl butyrate, or ethyl butyrate is preferred from the viewpoints of improving ionic conductivity due to a decrease in viscosity and suppressing battery swelling during endurance such as cycling and storage.

[0157] The content of the chain carboxylic acid ester is not particularly limited and may be any amount as long as it does not significantly impair the effects of the present invention. It is usually 5% by volume or more, preferably 8% by volume or more, and usually 80% by volume or less, preferably 70% by volume or less, based on 100% by volume of the non-aqueous solvent. When the content of the chain carboxylic acid ester is within the above range, the electrical conductivity of the non-aqueous electrolyte is improved, and the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte secondary battery are easily improved. Furthermore, an increase in negative electrode resistance is suppressed, and the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte secondary battery are easily maintained within a favorable range. When a chain carboxylic acid ester is used, it is preferably used in combination with a cyclic carbonate, and more preferably a combination of a cyclic carbonate and a chain carbonate.

[0158] For example, when a cyclic carbonate and a chain carboxylic acid ester are used in combination, the content of the cyclic carbonate is not particularly limited and can be any content as long as the effects of the present invention are not significantly impaired, but is usually 15% by volume or more, preferably 20% by volume, and usually 45% by volume or less, preferably 40% by volume or less, and the content of the chain carboxylic acid ester is usually 20% by volume or more, preferably 30% by volume or more, and usually 55% by volume or less, preferably 50% by volume or less. Furthermore, when a cyclic carbonate, a chain carbonate, and a chain carboxylic acid ester are used in combination, the content of the cyclic carbonate is not particularly limited and can be any content as long as the effects of the present invention are not significantly impaired, but is usually 15% by volume or more, preferably 20% by volume, and usually 45% by volume or less, preferably 40% by volume or less, and the content of the chain carbonate is usually 25% by volume or more, preferably 30% by volume or more, and usually 84% by volume or less, preferably 80% by volume or less. By setting the content within the above range, the low-temperature deposition temperature of the electrolyte is lowered while the viscosity of the nonaqueous electrolytic solution is also lowered, improving ionic conductivity, and higher input / output can be obtained even at low temperatures, which is preferable from the viewpoint of further reducing battery swelling.

[0159] <1-1-5-4. Cyclic Carboxylic Acid Ester> Examples of cyclic carboxylic acid esters include those having a total of 3 to 12 carbon atoms in their structural formula. Specific examples include gamma-butyrolactone, gamma-valerolactone, gamma-caprolactone, and epsilon-caprolactone. Among these, gamma-butyrolactone is particularly preferred from the viewpoint of improving battery characteristics due to an improved degree of lithium ion dissociation. The content of the cyclic carboxylic acid ester is not particularly limited and may be any amount as long as it does not significantly impair the effects of the present invention. However, the content is typically 3% by volume or more, preferably 5% by volume or more, and typically 60% by volume or less, preferably 50% by volume or less, based on 100% by volume of the nonaqueous solvent. Setting the content of the cyclic carboxylic acid ester within the above range improves the electrical conductivity of the nonaqueous electrolyte and facilitates improving the input / output characteristics and charge / discharge rate characteristics of the nonaqueous electrolyte secondary battery. Furthermore, by keeping the viscosity of the nonaqueous electrolyte within an appropriate range, a decrease in electrical conductivity can be avoided, an increase in negative electrode resistance can be suppressed, and the input / output characteristics and charge / discharge rate characteristics of the nonaqueous electrolyte secondary battery can be easily kept within good ranges.

[0160] <1-1-5-5. Ether Compounds> As the ether compounds, chain ethers having 3 to 10 carbon atoms and cyclic ethers having 3 to 6 carbon atoms are preferred. Examples of chain ethers having 3 to 10 carbon atoms include diethyl ether, di(2-fluoroethyl)ether, di(2,2-difluoroethyl)ether, di(2,2,2-trifluoroethyl)ether, ethyl(2-fluoroethyl)ether, ethyl(2,2,2-trifluoroethyl)ether, ethyl(1,1,2,2-tetrafluoroethyl)ether, (2-fluoroethyl)(2,2,2-trifluoroethyl)ether, (2-fluoroethyl)(1,1,2,2-tetrafluoroethyl)ether, (2,2,2-trifluoroethyl)(1,1,2,2-tetrafluoroethyl)ether, ethyl-n-propyl ether, ethyl (3-fluoro-n-propyl)ether, ethyl (3,3,3-trifluoro-n-propyl)ether, ethyl (2,2,3,3-tetrafluoro-n-propyl)ether, ethyl (2,2,3,3,3-pentafluoro-n-propyl)ether, 2-fluoroethyl-n-propyl ether, (2-fluoroethyl)(3-fluoro-n-propyl)ether, (2- 2,2,2-trifluoroethyl)(3,3,3-trifluoro-n-propyl) ether, (2-fluoroethyl)(2,2,3,3-tetrafluoro-n-propyl) ether, (2-fluoroethyl)(2,2,3,3,3-pentafluoro-n-propyl) ether, 2,2,2-trifluoroethyl-n-propyl ether, (2,2,2-trifluoroethyl)(3-fluoro-n-propyl) ether, (2,2,2-trifluoroethyl)(3,3,3-trifluoro-n-propyl) ether, (2,2,2- trifluoroethyl)(2,2,3,3-tetrafluoro-n-propyl) ether, (2,2,2-trifluoroethyl)(2,2,3,3,3-pentafluoro-n-propyl) ether, 1,1,2,2-tetrafluoroethyl-n-propyl ether, (1,1,2,2-tetrafluoroethyl)(3-fluoro-n-propyl) ether, (1,1,2,2-tetrafluoroethyl)(3,3,3-trifluoro-n-propyl) ether, (1,1,2,2-tetrafluoroethyl)(2,2,3,3-tetrafluoro-n-propyl) ether, (1,1,2,2-tetrafluoroethyl)(2,2,3,3,3-pentafluoro-n-propyl) ether, di-n-propyl ether, (n-propyl)(3-fluoro-n-propyl) ether, (n-propyl)(3,3,3-trifluoro-n-propyl) ether, (n-propyl)(2,2,3,3-tetrafluoro-n-propyl) ether, (n-propyl)(2,2,3,3,3-pentafluoro-n-propyl) ether, di(3-fluoro-n-propyl) ether (3-fluoro-n-propyl)(3,3,3-trifluoro-n-propyl)ether, (3-fluoro-n-propyl)(2,2,3,3-tetrafluoro-n-propyl)ether, (3-fluoro-n-propyl)(2,2,3,3-pentafluoro-n-propyl)ether, di(3,3,3-trifluoro-n-propyl)ether, (3,3,3-trifluoro-n-propyl)(2,2,3,3-tetrafluoro-n-propyl)ether, (3,3,3-trifluoro-n-propyl)(2,2,3,3-pentafluoro-n-propyl)ether di(2,2,3,3-tetrafluoro-n-propyl)ether, di(2,2,3,3-tetrafluoro-n-propyl)ether, (2,2,3,3-tetrafluoro-n-propyl)(2,2,3,3,3-pentafluoro-n-propyl)ether, di(2,2,3,3,3-pentafluoro-n-propyl)ether, di-n-butyl ether, dimethoxymethane, methoxyethoxymethane, methoxy(2-fluoroethoxy)methane, methoxy(2,2,2-trifluoroethoxy)methane, methoxy(1,1,2,2-tetrafluoroethoxy)methane, di Ethoxymethane, ethoxy(2-fluoroethoxy)methane, ethoxy(2,2,2-trifluoroethoxy)methane, ethoxy(1,1,2,2-tetrafluoroethoxy)methane, di(2-fluoroethoxy)methane, (2-fluoroethoxy)(2,2,2-trifluoroethoxy)methane, (2-fluoroethoxy)(1,1,2,2-tetrafluoroethoxy)methane di(2,2,2-trifluoroethoxy)methane, (2,2,2-trifluoroethoxy)(1,1,2,2-tetrafluoroethoxy)methane, di(1,1,2,2-tetrafluoroethoxy)methane, dimethoxyethane, methoxyethoxyethane, methoxy(2-fluoroethoxy)ethane, methoxy(2,2,2-trifluoroethoxy)ethane, methoxy(1,1,2,2-tetrafluoroethoxy)ethane, diethoxyethane, ethoxy(2-fluoroethoxy)ethane, ethoxy(2,2,2-trifluoroethoxy)ethane, ethoxy(1,1,2,2-tetrafluoroethoxy)ethane, di(2-fluoroethoxy)ethane, (2-fluoroethoxy)ethane (2,2,2-trifluoroethoxy)ethane, (2-fluoroethoxy)(1,1,2,2-tetrafluoroethoxy)ethane, di(2,2,2-trifluoroethoxy)ethane, (2,2,2-trifluoroethoxy)(1,1,2,2-tetrafluoroethoxy)ethane, di(1,1,2,2-tetrafluoroethoxy)ethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether, and the like.

[0161] Examples of cyclic ethers having 3 to 6 carbon atoms include tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 1,3-dioxane, 2-methyl-1,3-dioxane, 4-methyl-1,3-dioxane, 1,4-dioxane, and fluorinated compounds thereof.

[0162] Among these, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether are preferred in that they have a high ability to solvate lithium ions and improve ionic dissociation. Dimethoxymethane, diethoxymethane, and ethoxymethoxymethane are particularly preferred because they have low viscosity and provide high ionic conductivity.

[0163] The content of the ether-based compound is not particularly limited and may be any amount as long as it does not significantly impair the effects of the present invention. 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, based on 100% by volume of the nonaqueous solvent. When the content of the ether-based compound is within the above-mentioned preferred range, it is easy to ensure the effect of improving the degree of lithium ion dissociation of the chain ether and improving ionic conductivity due to reduced viscosity. Furthermore, when the negative electrode active material is a carbonaceous material, the phenomenon of co-insertion of the chain ether with lithium ions can be suppressed, thereby allowing the input / output characteristics and charge / discharge rate characteristics to be within appropriate ranges.

[0164] <1-1-5-6. Sulfone Compounds> Preferred sulfone compounds are cyclic sulfones having 3 to 6 carbon atoms and chain sulfones having 2 to 6 carbon atoms. The number of sulfonyl groups in one molecule is preferably 1 or 2.

[0165] Examples of cyclic sulfones include monosulfone compounds such as trimethylene sulfones, tetramethylene sulfones, and hexamethylene sulfones; and disulfone compounds such as trimethylene disulfones, tetramethylene disulfones, and hexamethylene disulfones. Among these, from the viewpoints of dielectric constant and viscosity, tetramethylene sulfones, tetramethylene disulfones, hexamethylene sulfones, and hexamethylene disulfones are more preferred, and tetramethylene sulfones (sulfolanes) are particularly preferred.

[0166] The sulfolanes are preferably sulfolane and / or sulfolane derivatives (hereinafter, sulfolane may also be abbreviated as "sulfolanes"). The sulfolane derivatives are preferably those in which one or more hydrogen atoms bonded to the carbon atoms constituting the sulfolane ring are substituted with a fluorine atom or an alkyl group.

[0167] Among these, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, 2,2-difluorosulfolane, 2,3-difluorosulfolane, 2,4-difluorosulfolane, 2,5-difluorosulfolane, 3,4-difluorosulfolane, 2-fluoro-3-methylsulfolane, 2-fluoro-2-methylsulfolane, 3-fluoro-3-methylsulfolane, 3-fluoro-2-methylsulfolane, 4-fluoro-3-methylsulfolane, 4-fluoro-2-methylsulfolane, 5-fluoro-3-methylsulfolane Perfluorolane, 5-fluoro-2-methylsulfolane, 2-fluoromethylsulfolane, 3-fluoromethylsulfolane, 2-difluoromethylsulfolane, 3-difluoromethylsulfolane, 2-trifluoromethylsulfolane, 3-trifluoromethylsulfolane, 2-fluoro-3-(trifluoromethyl)sulfolane, 3-fluoro-3-(trifluoromethyl)sulfolane, 4-fluoro-3-(trifluoromethyl)sulfolane, 5-fluoro-3-(trifluoromethyl)sulfolane, and the like are preferred because they have high ionic conductivity and high input / output.

[0168] Examples of chain sulfones include dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, n-propyl ethyl sulfone, di-n-propyl sulfone, isopropyl methyl sulfone, isopropyl ethyl sulfone, diisopropyl sulfone, n-butyl methyl sulfone, n-butyl ethyl sulfone, t-butyl methyl sulfone, t-butyl ethyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone, monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, and perfluoroethyl methyl sulfone. Examples thereof include fluoromethyl-n-propyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di(trifluoroethyl)sulfone, perfluorodiethyl sulfone, fluoromethyl-n-propyl sulfone, difluoromethyl-n-propyl sulfone, trifluoromethyl-n-propyl sulfone, fluoromethyl isopropyl sulfone, difluoromethyl isopropyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl-n-propyl sulfone, trifluoroethyl isopropyl sulfone, pentafluoroethyl-n-propyl sulfone, pentafluoroethyl isopropyl sulfone, trifluoroethyl-n-butyl sulfone, trifluoroethyl-t-butyl sulfone, pentafluoroethyl-n-butyl sulfone, and pentafluoroethyl-t-butyl sulfone.

[0169] Among these, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, isopropyl methyl sulfone, n-butyl methyl sulfone, t-butyl methyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone, monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, trifluoromethyl-n-propyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl-n-butyl sulfone, trifluoroethyl-t-butyl sulfone, trifluoromethyl-n-butyl sulfone or trifluoromethyl-t-butyl sulfone is preferred in terms of high ionic conductivity and high input / output.

[0170] The content of the sulfone-based compound is not particularly limited and may be any content as long as it does not significantly impair the effects of the present invention, but is usually 0.3 vol% or more, preferably 0.5 vol% or more, more preferably 1 vol% or more, and usually 40 vol% or less, preferably 35 vol% or less, more preferably 30 vol% or less, based on 100 vol% of the nonaqueous solvent. If the content of the sulfone-based compound is within the above range, it is easy to obtain an effect of improving durability such as cycle characteristics and storage characteristics, and it is also possible to keep the viscosity of the nonaqueous electrolyte within an appropriate range, avoid a decrease in electrical conductivity, and keep the input / output characteristics and charge / discharge rate characteristics of the nonaqueous electrolyte secondary battery within appropriate ranges.

[0171] <1-1-6. Auxiliary Agents> The nonaqueous electrolyte solution of this embodiment may further contain various auxiliary agents, which will be described in detail below.

[0172] <1-1-6-1. Overcharge Inhibitor> Specific examples of overcharge inhibitors include toluene derivatives such as toluene, xylene, 2-fluorotoluene, 3-fluorotoluene, and 4-fluorotoluene; unsubstituted or alkyl group-substituted biphenyl derivatives such as biphenyl, 2-methylbiphenyl, 3-methylbiphenyl, and 4-methylbiphenyl; unsubstituted or alkyl group-substituted terphenyl derivatives such as o-terphenyl, m-terphenyl, and p-terphenyl; partial hydrogenations of unsubstituted or alkyl group-substituted terphenyl derivatives; cycloalkylbenzene derivatives such as cyclopentylbenzene and cyclohexylbenzene; alkylbenzene derivatives having a tertiary carbon directly bonded to a benzene ring such as cumene, 1,3-diisopropylbenzene, and 1,4-diisopropylbenzene; alkylbenzene derivatives having a quaternary carbon directly bonded to a benzene ring such as t-butylbenzene, t-amylbenzene, t-hexylbenzene, and 1,1,3-trimethyl-3-phenylindane; aromatic compounds having an oxygen atom such as diphenyl ether and dibenzofuran; and other aromatic compounds.

[0173] Further, specific examples of other overcharge inhibitors include partially fluorinated compounds of the above aromatic compounds, such as fluorobenzene, benzotrifluoride, 2-fluorobiphenyl, o-cyclohexylfluorobenzene, and p-cyclohexylfluorobenzene; and fluorine-containing anisole compounds, such as 2,4-difluoroanisole, 2,5-difluoroanisole, and 1,6-difluoroanisole. These overcharge inhibitors may be used alone, or two or more may be used in any combination and ratio. When any combination is used, the compounds may be from the same class as exemplified above, or may be from different classes.

[0174] When an overcharge inhibitor is added, the amount of the overcharge inhibitor may be any amount as long as it does not significantly impair the effects of the present invention, but is preferably in the range of 0.001% by mass or more and 10% by mass or less relative to the total non-aqueous electrolyte solution (100% by mass). By adding an overcharge inhibitor to the non-aqueous electrolyte solution of this embodiment within a range that does not significantly impair the effects of the present invention, the safety of the energy device can be improved so that there is no problem even if the overcharge protection circuit does not operate normally due to incorrect usage or an abnormality in the charging device, causing overcharging, and this is preferable.

[0175] <1-1-6-2. Other Auxiliaries> Specific examples of other auxiliaries for improving the capacity retention characteristics and cycle characteristics after high-temperature storage include the following. Carbonate compounds other than those corresponding to carbonates having an unsaturated bond, such as erythritan carbonate and spiro-bis-dimethylene carbonate; cyclic sulfites such as ethylene sulfite; non-fluorinated cyclic sulfates such as ethylene sulfate, vinylene sulfate and propylene sulfate; chain sulfonate esters such as methyl methanesulfonate and busulfan; cyclic sulfones such as sulfolane and sulfolene; chain sulfones such as dimethyl sulfone, diphenyl sulfone and methyl phenyl sulfone; sulfides such as dibutyl disulfide, dicyclohexyl disulfide and tetramethylthiuram monosulfide; sulfur-containing compounds such as sulfonamides such as N,N-dimethylmethanesulfonamide and N,N-diethylmethanesulfonamide; nitrogen-containing compounds such as 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidinone and 1,3-dimethyl-2-imidazolidinone; Hydrocarbon compounds such as heptane, octane, and cycloheptane;2-(diethoxyphosphoryl)propargyl acetate, 2-butynyl 2-(diethoxyphosphoryl)acetate, 2-(methanesulfonyloxy)propionate propargyl, methanesulfonyloxypropargyl acetate, lithium ethyl propargyloxycarbonylphosphonate, lithium ethyl 2-butynyloxycarbonylphosphonate, lithium propargyl sulfate, 2-butynyllithium sulfate, propargyltrimethylsilyl sulfate, 2-butyne-1,4-diyl dimesylate, 2-butyne-1,4-diyl diethanesulfonate, 2-butyne-1,4-diyl diformate, 2-butyne-1,4-diyl diacetate, 2-butyne-1,4-diyl dipropionate, 4-hexadiyn-1,6-diyl Triple bond compounds such as dimethanesulfonate, propargyl methanesulfonate, 2-butynyl methanesulfonate, propargyl ethanesulfonate, propargyl vinylsulfonate, propargyl methyl carbonate, propargyl ethyl carbonate, dipropargyl carbonate, propargyl formate, propargyl acetate, propargyl methacrylate, methyl propargyl oxalate, ethyl propargyl oxalate, and dipropargyl oxalate; Silane compounds such as tris(trimethylsilyl) borate, tris(trimethoxysilyl) borate, tris(trimethylsilyl) phosphate, tris(trimethoxysilyl) phosphate, dimethoxyaluminoxytrimethoxysilane, diethoxyaluminoxytriethoxysilane, dipropoxyaluminoxytriethoxysilane, dibutoxyaluminoxytrimethoxysilane, dibutoxyaluminoxytriethoxysilane, titanium tetrakis(trimethylsiloxide), and titanium tetrakis(triethylsiloxide); fluorine-containing aromatic compounds such as fluorobenzene, difluorobenzene, and benzotrifluoride; pentafluorophenyl compounds such as pentafluorophenyl methanesulfonate, pentafluorophenyl trifluoromethanesulfonate, pentafluorophenyl acetate, pentafluorophenyl trifluoroacetate, and methyl pentafluorophenyl carbonate. These other auxiliary agents may be used alone or in any combination and ratio of two or more.

[0176] Furthermore, when the nonaqueous electrolyte solution of this embodiment contains these other auxiliary agents, the content thereof is arbitrary as long as it does not significantly impair the effects of the present invention, but is preferably in the range of 0.001% by mass or more and 10% by mass or less relative to the total nonaqueous electrolyte solution (100% by mass). The nonaqueous electrolyte solution described above also includes those present inside energy devices such as nonaqueous electrolyte secondary batteries according to one embodiment of the present invention. Specifically, the nonaqueous electrolyte solution may be a nonaqueous electrolyte solution in a nonaqueous electrolyte secondary battery obtained by separately synthesizing and substantially isolating components of the nonaqueous electrolyte solution, preparing a nonaqueous electrolyte solution from the resulting solution, and injecting the solution into a separately assembled battery by the method described below. Also included are cases where the components of the nonaqueous electrolyte solution of this embodiment are individually placed in a battery and mixed in the nonaqueous electrolyte secondary battery to obtain the same composition as the nonaqueous electrolyte solution of this embodiment. Furthermore, cases where compounds constituting the nonaqueous electrolyte solution of this embodiment are generated in the nonaqueous electrolyte secondary battery to obtain the same composition as the nonaqueous electrolyte solution of this embodiment are also included.

[0177] <1-2. Method for producing non-aqueous electrolyte solution> The non-aqueous electrolyte solution of this embodiment is the non-aqueous solvent, the electrolyte, the general formula (A1) and / or (A2) represented by the compound (general formula (A1) and (A2) at least one selected from the compounds), or the general formula (B1) and / or (B2) represented by the compound (general formula (B1) and (B2) at least one selected from the compounds), and, if necessary, the specific compound, the "auxiliary agent" and the like can be prepared by dissolving. When preparing the non-aqueous electrolyte solution, each raw material of the non-aqueous electrolyte solution, that is, an electrolyte such as a lithium salt, a compound represented by the general formula (A1) and / or (A2) (general formula (A1) and (A2) at least one selected from the compounds), or the general formula (B1) and / or (B2) represented by the compound (general formula (B1) and (B2) at least one selected from the compounds), the specific compound, the non-aqueous solvent, the auxiliary agent, etc. are preferably dehydrated in advance. The degree of dehydration is usually 50 ppm or less, preferably 30 ppm or less.

[0178] Removing water from the nonaqueous electrolyte solution makes it difficult for electrolysis of water, reactions between water and lithium metal, and hydrolysis of lithium salts to occur. There are no particular limitations on the dehydration method. For example, when the object to be dehydrated is a liquid such as a nonaqueous solvent, a desiccant such as a molecular sieve may be used. Furthermore, when the object to be dehydrated is a solid such as an electrolyte, it may be dried by heating below the temperature at which decomposition occurs.

[0179] 2. Energy Device Using Non-Aqueous Electrolyte Solution An energy device using the non-aqueous electrolyte solution of this embodiment includes a plurality of electrodes capable of absorbing or releasing metal ions and the non-aqueous electrolyte solution of this embodiment described above. Specific examples of types of energy devices include primary batteries, secondary batteries, and metal ion capacitors such as lithium ion capacitors. Among these, primary batteries or secondary batteries are preferred, and secondary batteries are particularly preferred. It is also preferable that the non-aqueous electrolyte solution used in these energy devices is a so-called gel electrolyte that is pseudo-solidified with a polymer, filler, or the like. The energy device will be described below.

[0180] <2-1. Nonaqueous Electrolyte Secondary Battery> <2-1-1. Battery Configuration> A nonaqueous electrolyte secondary battery according to one embodiment of the present invention (hereinafter also referred to as the nonaqueous secondary battery of this embodiment) has the same configuration as conventionally known nonaqueous electrolyte secondary batteries, except for the nonaqueous electrolyte, and typically has a configuration in which a positive electrode and a negative electrode are stacked via a porous membrane (separator) impregnated with the nonaqueous electrolyte of this embodiment, and these are housed in a case (exterior body). Therefore, the shape of the nonaqueous electrolyte secondary battery of this embodiment is not particularly limited, and may be any of a cylindrical type, a prismatic type, a laminate type, a coin type, a large type, etc.

[0181] <2-1-2. Non-aqueous electrolyte> The non-aqueous electrolyte of the present embodiment is used as the non-aqueous electrolyte. Note that, within the scope of the present invention, it is also possible to mix the non-aqueous electrolyte of the present embodiment with other non-aqueous electrolytes.

[0182] <2-1-3. Negative Electrode> The negative electrode active material used in the negative electrode is not particularly limited as long as it is capable of electrochemically absorbing and releasing metal ions. Specific examples include carbonaceous materials, metal compound materials, and lithium-containing metal composite oxide materials. One of these may be used alone, or two or more may be used in any combination. Of these, carbonaceous materials and metal compound materials are preferred. Among metal compound materials, silicon-containing materials are preferred, and therefore carbonaceous materials and silicon-containing materials are more preferred as negative electrode active materials. Furthermore, in combination with the nonaqueous electrolyte solution of the second embodiment, it is particularly preferred that the negative electrode active material contain silicon atoms.

[0183] <2-1-3-1. Carbonaceous Material> The carbonaceous material used as the negative electrode active material is not particularly limited, but is preferably selected from the following (A) to (D) because it provides a secondary battery with a well-balanced initial irreversible capacity and high current density charge / discharge characteristics: (A) natural graphite (B) a carbonaceous material obtained by heat-treating an artificial carbonaceous material or an artificial graphite material at least once in the range of 400°C to 3200°C (C) a carbonaceous material in which the negative electrode active material layer is made of carbonaceous material having at least two different types of crystallinity and / or has an interface where the carbonaceous material having the different crystallinity contacts (D) a carbonaceous material in which the negative electrode active material layer is made of carbonaceous material having at least two different types of orientation and / or has an interface where the carbonaceous material having the different orientation contacts One of the carbonaceous materials (A) to (D) may be used alone, or two or more may be used in any combination and ratio.

[0184] Specific examples of the artificial carbonaceous material or artificial graphite material in (a) above include natural graphite, coal-based coke, petroleum-based coke, coal-based pitch, petroleum-based pitch, and these pitches that have been oxidized; needle coke, pitch coke, and carbon materials obtained by partially graphitizing these; pyrolysis products of organic substances such as furnace black, acetylene black, and pitch-based carbon fiber; carbonizable organic substances and carbonized products thereof; and solution-like carbonized products obtained by dissolving carbonizable organic substances in low-molecular-weight organic solvents such as benzene, toluene, xylene, quinoline, and n-hexane. The carbonaceous materials in (a) to (d) above are all well known, and their production methods are well known to those skilled in the art. Furthermore, these commercially available products can also be purchased.

[0185] <2-1-3-2. Metal Compound Material> The metal compound material used as the negative electrode active material is not particularly limited as long as it is capable of absorbing and releasing lithium, and examples thereof include elemental metals or alloys that form alloys with lithium, as well as compounds such as oxides, carbides, nitrides, silicides, sulfides, and phosphides thereof. Examples of such metal compounds include compounds containing metals such as Ag, Al, Ba, Bi, Cu, Ga, Ge, In, Ni, P, Pb, Sb, Si, Sn, Sr, and Zn. Among these, elemental metals or alloys that form alloys with lithium are preferred, and materials containing metal or metalloid elements (i.e., excluding carbon; hereinafter, metals and metalloids will be collectively referred to as "metals") from Group 13 or 14 of the periodic table are more preferred, and further, elemental metals such as silicon (Si), tin (Sn), or lead (Pb) (hereinafter, these three elements may be referred to as "SSP metal elements"), alloys containing these atoms, or compounds of these metals (SSP metal elements) are preferred. Compounds containing silicon are particularly preferred. These may be used alone or in any combination and ratio of two or more.

[0186] In this embodiment, the content of the metal compound-based material relative to the total amount of the negative electrode active material is preferably 1 mass% or more, more preferably 3 mass% or more, and even more preferably 5 mass% or more, and may be 100 mass%.

[0187] Examples of negative electrode active materials containing at least one atom selected from SSP metal elements include a single metal of any one SSP metal element, an alloy of two or more SSP metal elements, an alloy of one or more SSP metal elements with one or more other metal elements, and a compound containing one or more SSP metal elements, or a composite compound of the compound, such as an oxide, carbide, nitride, silicide, sulfide, or phosphide. Using these single metals, alloys, or metal compounds as the negative electrode active material makes it possible to increase the capacity of the battery.

[0188] Further examples include compounds in which these composite compounds are intricately bonded with several elements, such as simple metals, alloys, or nonmetallic elements. More specifically, for example, in the case of silicon (Si) or tin (Sn), alloys of these elements and metals that do not function as a negative electrode can be used. Furthermore, for example, in the case of tin, complex compounds containing five to six elements can be used, which are combinations of a metal other than tin and silicon that functions as a negative electrode, a metal that does not function as a negative electrode, and a nonmetallic element.

[0189] Among these negative electrode active materials, a metal simple substance of any one of the SSP metal elements, an alloy of two or more SSP metal elements, an oxide, carbide, nitride, etc. of the SSP metal element are preferred because they have a large capacity per unit mass when made into a battery. In particular, a metal simple substance, alloy, oxide, carbide, nitride, etc. of silicon (Si) and / or tin (Sn) are preferred, and a metal simple substance, alloy, oxide (SiO ｘ ) and carbide (SiC ｘ ), nitride (SiN ｘ ), nitride oxide (SiN ｘ O ｙ ), carbide oxide (SiC ｘ O ｙ ) are more preferable from the viewpoint of capacity per unit mass and environmental load. Among these, metal Si and SiO ｘ is particularly preferred.

[0190] Although the capacity per unit mass is inferior to that of elemental metals or alloys, the following compounds containing silicon and / or tin are also preferred because of their excellent cycle characteristics: "Oxides of silicon and / or tin" in which the atomic ratio of silicon and / or tin to oxygen is usually 0.2 or more, preferably 0.3 or more, more preferably 0.5 or more, and usually 1.5 or less, preferably 1.3 or less, and even more preferably 1.1 or less; "Nitrides of silicon and / or tin" in which the atomic ratio of silicon and / or tin to nitrogen is usually 0.2 or more, preferably 0.3 or more, more preferably 0.5 or more, and usually 1.5 or less, preferably 1.3 or less, and even more preferably 1.1 or less; "Carbides of silicon and / or tin" in which the atomic ratio of silicon and / or tin to carbon is usually 0.2 or more, preferably 0.3 or more, more preferably 0.5 or more, and usually 1.5 or less, preferably 1.3 or less, and even more preferably 1.1 or less. The above-mentioned negative electrode active materials may be used alone or in any combination of two or more in any ratio.

[0191] General formula SiO ｘ is silicon dioxide (SiO ２ The value of x is usually 0 or more and less than 2, more preferably 0.2 or more and 1.8 or less, even more preferably 0.4 or more and 1.6 or less, and particularly preferably 0.6 or more and 1.4 or less. Also, x=0 is preferable. Within this range, it is possible to achieve high capacity and simultaneously reduce irreversible capacity due to bonding between Li and oxygen.

[0192] The above-mentioned negative electrode active materials may be used alone or in any combination of two or more in any ratio.

[0193] <2-1-3-3. Lithium-Containing Metal Composite Oxide Material> The lithium-containing metal composite oxide material used as the negative electrode active material is not particularly limited as long as it is capable of absorbing and releasing lithium. However, a lithium-containing composite metal oxide material containing titanium is preferred, and a composite oxide of lithium and titanium (hereinafter sometimes abbreviated as "lithium titanium composite oxide") is particularly preferred. That is, when a lithium titanium composite oxide having a spinel structure is incorporated into a negative electrode active material for a lithium ion nonaqueous electrolyte secondary battery, the output resistance of the secondary battery is significantly reduced, which is particularly preferred. Also preferred are lithium titanium composite oxides in which the lithium and titanium are substituted with other metal elements, such as at least one element selected from the group consisting of Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn, and Nb.

[0194] A lithium titanium composite oxide preferred as a negative electrode active material is represented by the following general formula (7): Li ｘ Ti ｙ M ｚ O ４ (7) (In general formula (7), M represents at least one element selected from the group consisting of Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn, and Nb. In addition, in general formula (7), it is preferable that 0.7≦x≦1.5, 1.5≦y≦2.3, and 0≦z≦1.6, because the structure is stable during doping and dedoping of lithium ions.)

[0195] <2-1-3-4. Negative Electrode Configuration, Properties, and Preparation Method> The negative electrode containing the active material, the electrode fabrication method, and the current collector may employ known technical configurations, but it is desirable that one or more of the following (i) to (vi) conditions be met simultaneously. (i) Negative Electrode Fabrication Any known method can be used to manufacture the negative electrode, as long as it does not significantly limit the effects of the present invention. For example, a negative electrode active material may be prepared by adding a binder, a solvent, and, if necessary, a thickener, a conductive material, a filler, etc. to the negative electrode active material to form a slurry-like negative electrode-forming material. This slurry is then applied to a current collector, dried, and then pressed to form a negative electrode active material layer.

[0196] (ii) Current Collector Any known current collector can be used as the current collector that holds the negative electrode active material. Examples of the negative electrode current collector include metal materials such as aluminum, copper, nickel, stainless steel, and nickel-plated steel, with copper being particularly preferred in terms of ease of processing and cost. Furthermore, when the current collector is made of a metal material, examples of the shape of the current collector include metal foil, metal cylinder, metal coil, metal plate, metal thin film, expanded metal, punched metal, and foamed metal. Among these, metal thin film is preferred, copper foil is more preferred, and rolled copper foil produced by rolling and electrolytic copper foil produced by electrolysis are even more preferred.

[0197] (iii) Thickness Ratio of Current Collector to Negative Electrode Active Material Layer The thickness ratio of the current collector to the negative electrode active material layer is not particularly limited, but the value of "(thickness of the negative electrode active material layer on one side immediately before the non-aqueous electrolyte injection step) / (thickness of the current collector)" is preferably 150 or less, more preferably 20 or less, particularly preferably 10 or less, and also preferably 0.1 or more, more preferably 0.4 or more, particularly preferably 1 or more. If the thickness ratio of the current collector to the negative electrode active material layer exceeds the above range, the current collector may generate heat due to Joule heat during high current density charge / discharge of the secondary battery. Furthermore, if it is below the above range, the volume ratio of the current collector to the negative electrode active material increases, which may reduce the capacity of the secondary battery.

[0198] (iv) Electrode Density The electrode structure when the negative electrode active material is made into an electrode is not particularly limited, and the density of the negative electrode active material present on the current collector is 1 g cm －３ More than 1.2 g cm －３ More preferably, 1.3 g cm or more －３ More preferably, 4 g cm －３ Preferably, 3 g cm or less －３ More preferably, 2.5 g cm －３ More preferably, 1.7 g cm －３The following is particularly preferred. When the density of the negative electrode active material present on the current collector is within the above range, the negative electrode active material particles are less likely to be destroyed, making it easier to prevent an increase in the initial irreversible capacity of the secondary battery and deterioration of high current density charge / discharge characteristics due to reduced permeability of the nonaqueous electrolyte solution near the current collector / negative electrode active material interface. Furthermore, conductivity between the negative electrode active materials can be ensured, and capacity per unit volume can be increased without increasing battery resistance.

[0199] (v) Binder, Solvent, etc. The slurry for forming the negative electrode active material layer is usually prepared by adding a mixture of a solvent, a binder (binding agent), a thickener, etc. to the negative electrode active material. The binder for binding the negative electrode active material is not particularly limited as long as it is a material that is stable against the nonaqueous electrolyte solution and the solvent used in producing the electrode. Specific examples thereof include resin-based polymers such as polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, aromatic polyamide, cellulose, and nitrocellulose; rubber-like polymers such as SBR (styrene-butadiene rubber), isoprene rubber, butadiene rubber, fluororubber, NBR (acrylonitrile-butadiene rubber), and ethylene-propylene rubber; styrene-butadiene-styrene block copolymers or hydrogenated products thereof; thermoplastic elastomeric polymers such as EPDM (ethylene-propylene-diene terpolymer), styrene-ethylene-butadiene-styrene copolymers, and styrene-isoprene-styrene block copolymers or hydrogenated products thereof; soft resin-like polymers such as syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene-vinyl acetate copolymers, and propylene-α-olefin copolymers; fluorine-based polymers such as polyvinylidene fluoride, polytetrafluoroethylene, fluorinated polyvinylidene fluoride, and polytetrafluoroethylene-ethylene copolymers; and polymer compositions having ionic conductivity for alkali metal ions (particularly lithium ions). These may be used alone or in any combination of two or more in any ratio.

[0200] The solvent for forming the slurry is not particularly limited as long as it is capable of dissolving or dispersing the negative electrode active material, binder, and optionally used thickener and conductive material, and either an aqueous solvent or an organic solvent may be used. Examples of the aqueous solvent include water and alcohol, while examples of the organic solvent include N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine, N,N-dimethylaminopropylamine, tetrahydrofuran (THF), toluene, acetone, diethyl ether, dimethylacetamide, hexamethylphosphamide, dimethyl sulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene, and hexane. When using an aqueous solvent, it is preferable to add a dispersant or the like in addition to the thickener and form a slurry using a latex such as SBR. These solvents may be used alone or in any combination and ratio of two or more.

[0201] The ratio of the binder to 100 parts by mass of the negative electrode active material is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 0.6 parts by mass or more, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, even more preferably 10 parts by mass or less, and particularly preferably 8 parts by mass or less. When the ratio of the binder to the negative electrode active material is within the above range, the proportion of the binder that does not contribute to the battery capacity is not increased, so that a decrease in battery capacity is unlikely to occur. Furthermore, a decrease in the strength of the negative electrode is unlikely to occur.

[0202] In particular, when the slurry that is the negative electrode forming material contains a rubber-like polymer typified by SBR as a main component, the ratio of the binder to 100 parts by mass of the negative electrode active material is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 0.6 parts by mass or more, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less. Also, when the slurry contains a fluorine-based polymer typified by polyvinylidene fluoride as a main component, the ratio of the binder to 100 parts by mass of the negative electrode active material is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, and preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 8 parts by mass or less.

[0203] Thickeners are usually used to adjust the viscosity of the slurry. There are no particular limitations on the thickener, but specific examples include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein, and salts thereof. These may be used alone or in any combination and ratio of two or more.

[0204] When a thickener is used, the ratio of the thickener to 100 parts by mass of the negative electrode active material is usually 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 0.6 parts by mass or more. Furthermore, the ratio is usually 5 parts by mass or less, preferably 3 parts by mass or less, and more preferably 2 parts by mass or less. When the ratio of the thickener to the negative electrode active material is within the above range, the coating properties of the slurry are improved. Furthermore, the ratio of the negative electrode active material in the negative electrode active material layer is also appropriate, making it less likely that problems such as a decrease in battery capacity or an increase in resistance between the negative electrode active materials will occur.

[0205] (vi) Area of ​​the Negative Electrode Plate The area of ​​the negative electrode plate is not particularly limited, but it is preferable to design it to be slightly larger than the opposing positive electrode plate so that the positive electrode plate does not protrude beyond the negative electrode plate. Furthermore, from the viewpoint of suppressing the cycle life of the secondary battery when repeatedly charged and discharged and deterioration due to high-temperature storage, it is preferable to make the area as close as possible to the positive electrode, since this increases the proportion of electrodes that work more uniformly and effectively, improving the characteristics. In particular, when the secondary battery is used at a large current, the design of the area of ​​the negative electrode plate is important.

[0206] <2-1-4. Positive Electrode> The positive electrode used in the nonaqueous electrolyte secondary battery of this embodiment will be described below. <2-1-4-1. Positive Electrode Active Material> The positive electrode active material used in the positive electrode will be described below. (1) Composition There are no particular limitations on the positive electrode active material as long as it is capable of electrochemically absorbing and desorbing metal ions. For example, a material capable of electrochemically absorbing and desorbing lithium ions is preferred, and a material containing lithium and at least one transition metal is preferred. Specific examples include lithium transition metal composite oxides, lithium-containing transition metal phosphate compounds, lithium-containing transition metal silicate compounds, and lithium-containing transition metal borate compounds.

[0207] The transition metal of the lithium transition metal composite oxide is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu, or the like. Specific examples of the composite oxide include LiCoO ２ Lithium-cobalt composite oxides such as LiNiO ２ Lithium-nickel composite oxides such as LiMnO ２ , LiMn ２ O ４ , Li ２ MnO ４ and lithium-manganese composite oxides in which a part of the transition metal atoms that constitute the main components of these lithium transition metal composite oxides has been substituted with other metals such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, and W.

[0208] Specific examples of the substituted group include LiNi ０．５ Mn ０．５ O２ , LiNi ０．８５ Co ０．１０ Al ０．０５ O ２ , LiNi ０．３３ Co ０．３３ Mn ０．３３ O ２ , LiMn ２ O ４ , LiMn １．８ Al ０．２ O ４ , Li １．１ Mn １．９ Al ０．１ O ４ , LiMn １．５ Ni ０．５ O ４ Among them, a composite oxide containing lithium, nickel, and cobalt is more preferable because a composite oxide containing cobalt and nickel can have a large capacity when used at the same potential.

[0209] On the other hand, cobalt is a rare and expensive metal, and since large batteries requiring high capacity for automotive applications and the like require a large amount of active material, it is desirable to use manganese as a cheaper transition metal as the main component from the viewpoint of cost. That is, lithium-nickel-cobalt-manganese composite oxide is more preferable. Among them, from the viewpoint of achieving a high balance between cost and capacity, lithium-nickel-cobalt-manganese composite oxide in which the amount of cobalt is reduced and the amount of nickel is increased is particularly preferable. For example, LiNi ０．５ Co ０．２ Mn ０．３ O ２ and LiNi ０．６ Co ０．２ Mn ０．２ O ２ and LiNi ０．８ Co ０．１ Mn ０．１ O ２ are particularly preferred examples.

[0210] In addition, lithium manganese composite oxides having a spinel structure are also preferred in view of the stability of the compound and the procurement cost due to the ease of production.２ O ４ , LiMn １．８ Al ０．２ O ４ , Li １．１ Mn １．９ Al ０．１ O ４ , LiMn １．５ Ni ０．５ O ４ etc. can also be mentioned as preferred specific examples.

[0211] The transition metal of the lithium-containing transition metal phosphate compound is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu, or the like. Specific examples of the phosphate compound include LiFePO ４ , Li ３ Fe ２ (P.O. ４ ) ３ , LiFeP ２ O ７ Iron phosphates such as LiCoPO ４ Cobalt phosphates such as LiMnPO ４ and lithium transition metal phosphate compounds in which a part of the transition metal atoms that constitute the main component of these compounds is substituted with another metal such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, or W.

[0212] The transition metal of the lithium-containing transition metal silicate compound is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu, or the like. Specific examples of the silicate compound include Li, ２ FeSiO ４ Iron silicates such as Li ２ CoSiO ４ and lithium transition metal silicates in which a part of the transition metal atoms constituting the main component of these lithium transition metal silicates is substituted with another metal such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, or W.

[0213] The transition metal of the lithium-containing transition metal borate compound is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu, or the like. Specific examples of the borate compound include LiFeBO ３ Iron borates such as LiCoBO ３ and lithium transition metal borate compounds in which a part of the transition metal atoms that constitute the main component of these lithium transition metal borate compounds is substituted with another metal such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, or W.

[0214] (2) Manufacturing method of positive electrode active material The manufacturing method of the positive electrode active material is not particularly limited within the scope of the present invention, but several methods can be mentioned, and a general method for manufacturing an inorganic compound can be used. In particular, various methods can be considered for manufacturing a spherical or oval-spherical active material. For example, one example is to dissolve or pulverize and disperse a transition metal raw material such as a transition metal nitrate or sulfate, and, if necessary, raw materials of other elements, in a solvent such as water, and adjust the pH while stirring to prepare and recover a spherical precursor, which is then dried as necessary, and then dissolved in LiOH, Li ２ CO ３ , LiNO ３ and baking at a high temperature to obtain an active material.

[0215] Another example of the method is to dissolve or pulverize and disperse transition metal raw materials such as transition metal nitrates, sulfates, hydroxides, and oxides, and, if necessary, raw materials of other elements, in a solvent such as water, and then dry and mold them using a spray dryer or the like to form spherical or ellipsoidal precursors. ２ CO ３ , LiNO ３ and baking at a high temperature to obtain an active material.

[0216] As another example of the method, a transition metal source material such as a transition metal nitrate, sulfate, hydroxide, or oxide is reacted with LiOH, Li ２ CO ３ , LiNO ３and the like, and, if necessary, raw materials of other elements, are dissolved or pulverized and dispersed in a solvent such as water, and then dried and molded using a spray dryer or the like to form a spherical or oval spherical precursor, which is then fired at a high temperature to obtain an active material.

[0217] <2-1-4-2. Positive Electrode Structure and Fabrication Method> The following describes the configuration of the positive electrode used in the present invention and its fabrication method. (Fabrication Method of Positive Electrode) A positive electrode is fabricated by forming a positive electrode active material layer containing positive electrode active material particles and a binder on a current collector. Positive electrodes using positive electrode active materials can be fabricated by any known method. For example, a positive electrode can be obtained by dry-mixing a positive electrode active material and a binder, and optionally a conductive material and a thickener, into a sheet and pressing it onto a positive electrode current collector, or by dissolving or dispersing these materials in a liquid medium to form a slurry, which is then applied to a positive electrode current collector and dried to form a positive electrode active material layer on the current collector.

[0218] The content of the positive electrode active material in the positive electrode active material layer is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and preferably 99.9% by mass or less, more preferably 99% by mass or less. When the content of the positive electrode active material is within the above range, sufficient electrical capacity can be ensured. Furthermore, the strength of the positive electrode is also sufficient. The positive electrode active material powder in the present invention may be used alone, or two or more types having different compositions or different powder properties may be used in any combination and ratio. When two or more active materials are used in combination, it is preferable to use the composite oxide containing lithium and manganese as a powder component. As mentioned above, cobalt and nickel are expensive metals with limited resources. Therefore, in large batteries requiring high capacity, such as for automotive applications, the amount of active material used is large, which is undesirable from a cost perspective. Therefore, it is desirable to use manganese as a cheaper transition metal as the main component.

[0219] (Conductive Material) Any known conductive material can be used as the conductive material. Specific examples include metal materials such as copper and nickel; graphite (e.g., natural graphite and artificial graphite); carbon black such as acetylene black; and carbonaceous materials such as amorphous carbon (e.g., needle coke). These materials may be used alone or in any combination and ratio of two or more. The content of the conductive material in the positive electrode active material layer is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 1% by mass or more. It is also preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 15% by mass or less. When the content is within the above range, sufficient conductivity can be ensured. Furthermore, a decrease in battery capacity is also easily prevented.

[0220] (Binder) The binder used in producing the positive electrode active material layer is not particularly limited as long as it is a material that is stable to the non-aqueous electrolyte solution and the solvent used in producing the electrode. When the positive electrode is produced by a coating method, the binder is not particularly limited as long as it is a material that can be dissolved or dispersed in the liquid medium used in producing the electrode, and specific examples thereof include resin-based polymers such as polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, aromatic polyamide, cellulose, and nitrocellulose; rubber-like polymers such as SBR (styrene-butadiene rubber), NBR (acrylonitrile-butadiene rubber), fluororubber, isoprene rubber, butadiene rubber, and ethylene-propylene rubber; thermoplastic elastomeric polymers such as styrene-butadiene-styrene block copolymers or hydrogenated products thereof, EPDM (ethylene-propylene-diene terpolymer), styrene-ethylene-butadiene-ethylene copolymers, and styrene-isoprene-styrene block copolymers or hydrogenated products thereof; soft resin-like polymers such as syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene-vinyl acetate copolymers, and propylene-α-olefin copolymers; Fluorine-based polymers such as polyvinylidene fluoride (PVdF), polytetrafluoroethylene, fluorinated polyvinylidene fluoride, and polytetrafluoroethylene-ethylene copolymer; polymer compositions having ionic conductivity for alkali metal ions (particularly lithium ions). These substances may be used alone or in any combination and ratio of two or more.

[0221] The content of the binder in the positive electrode active material layer is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 3% by mass or more, and preferably 80% by mass or less, more preferably 60% by mass or less, even more preferably 40% by mass or less, and particularly preferably 10% by mass or less. When the binder ratio is within the above range, the positive electrode active material can be sufficiently retained, and the mechanical strength of the positive electrode can be ensured, resulting in good battery performance such as cycle characteristics. Furthermore, this also leads to avoiding a decrease in battery capacity and conductivity.

[0222] (Liquid Medium) The liquid medium used to prepare the slurry for forming the positive electrode active material layer is not particularly limited as long as it is a solvent capable of dissolving or dispersing the positive electrode active material, conductive material, binder, and thickener used as needed, and either an aqueous solvent or an organic solvent may be used. Examples of the aqueous medium include water and a mixture of alcohol and water. Examples of the organic medium include aliphatic hydrocarbons such as hexane; aromatic hydrocarbons such as benzene, toluene, xylene, and methylnaphthalene; heterocyclic compounds such as quinoline and pyridine; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; esters such as methyl acetate and methyl acrylate; amines such as diethylenetriamine and N,N-dimethylaminopropylamine; ethers such as diethyl ether and tetrahydrofuran (THF); amides such as N-methylpyrrolidone (NMP), dimethylformamide, and dimethylacetamide; and aprotic polar solvents such as hexamethylphosphalamide and dimethylsulfoxide. These may be used alone or in any combination of two or more in any ratio.

[0223] (Thickener) When an aqueous medium is used as the liquid medium for forming the slurry, it is preferable to use a thickener and a latex such as styrene butadiene rubber (SBR) to form the slurry. The thickener is usually used to adjust the viscosity of the slurry. There are no limitations on the thickener as long as it does not significantly limit the effects of the present invention, and specific examples include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphated starch, casein, and salts thereof. These may be used alone or in any combination and ratio of two or more.

[0224] When a thickener is used, the ratio of the thickener to the total mass of the positive electrode active material and the thickener is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 0.6% by mass or more, and preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less. Within the above range, the coating properties of the slurry are good, and the ratio of the active material in the positive electrode active material layer is sufficient, making it easier to avoid problems such as a decrease in the capacity of the secondary battery and an increase in resistance between the positive electrode active materials.

[0225] (Consolidation) The positive electrode active material layer obtained by applying the above slurry to the current collector and drying it is preferably consolidated by a hand press, a roller press, or the like in order to increase the packing density of the positive electrode active material. The density of the positive electrode active material layer is preferably 1 g cm －３ More than 1.5 g cm －３ More preferably, 2 g cm －３ More than 4 g cm is particularly preferred. －３ Preferably, 3.9 g cm or less －３ More preferably, 3.8 g cm or less －３ The following is particularly preferred. When the density of the positive electrode active material layer is within the above range, the permeability of the nonaqueous electrolyte solution near the current collector / active material interface is not reduced, and the charge / discharge characteristics of the secondary battery, particularly at high current densities, are improved. Furthermore, the conductivity between the active materials is less likely to decrease, and the battery resistance is less likely to increase.

[0226] (Current Collector) The material of the positive electrode current collector is not particularly limited, and any known material can be used. Specific examples include metal materials such as aluminum, stainless steel, nickel plating, titanium, and tantalum; and carbonaceous materials such as carbon cloth and carbon paper. Among these, metal materials, particularly aluminum, are preferred. Examples of the shape of the current collector include metal foil, metal cylinder, metal coil, metal plate, metal thin film, expanded metal, punched metal, and foamed metal in the case of metal materials, and carbonaceous materials include carbon plate, carbon thin film, and carbon cylinder. Of these, metal thin films are preferred. The thin film may be formed into a mesh shape as appropriate.

[0227] The thickness of the current collector is optional, but is preferably 1 μm or more, more preferably 3 μm or more, and even more preferably 5 μm or more, and is preferably 1 mm or less, more preferably 100 μm or less, and even more preferably 50 μm or less. When the thickness of the current collector is within the above range, the strength required as a current collector can be sufficiently ensured. Furthermore, handling is also improved.

[0228] The thickness ratio of the current collector to the positive electrode active material layer is not particularly limited, but (thickness of the active material layer on one side immediately before the nonaqueous electrolyte is poured) / (thickness of the current collector) is preferably 150 or less, more preferably 20 or less, particularly preferably 10 or less, and also preferably 0.1 or more, more preferably 0.4 or more, particularly preferably 1 or more. When the thickness ratio of the current collector to the positive electrode active material layer is within the above range, the current collector is less likely to generate heat due to Joule heat during high current density charge / discharge of the secondary battery. Furthermore, the volume ratio of the current collector to the positive electrode active material is less likely to increase, preventing a decrease in battery capacity.

[0229] (Electrode Area) From the viewpoint of improving high output and stability at high temperatures, the area of ​​the positive electrode active material layer is preferably larger than the outer surface area of ​​the battery outer case. Specifically, the total electrode area of ​​the positive electrode relative to the surface area of ​​the outer case of the nonaqueous electrolyte secondary battery is preferably 20 times or more, more preferably 40 times or more, in terms of area ratio. In the case of a bottomed prismatic outer case, the outer surface area refers to the total area calculated from the length, width, and thickness of the case portion filled with the power generating elements, excluding the terminal protrusions. In the case of a bottomed cylindrical outer case, the outer surface area refers to the geometric surface area of ​​the case portion filled with the power generating elements, excluding the terminal protrusions, approximated as a cylinder. The total electrode area of ​​the positive electrode refers to the geometric surface area of ​​the positive electrode composite layer facing the composite layer containing the negative electrode active material. In a structure in which positive electrode composite layers are formed on both sides via a current collector foil, the total area refers to the sum of the areas calculated separately for each side.

[0230] (Discharge Capacity) When using the nonaqueous electrolyte of this embodiment, it is preferable that the electrical capacity of the battery element housed in one battery exterior of the nonaqueous electrolyte secondary battery (the electrical capacity when the battery is discharged from a fully charged state to a discharged state) be 1 ampere-hour (Ah) or more, since this greatly improves the low-temperature discharge characteristics. Therefore, the positive electrode plate is designed so that the discharge capacity at full charge is preferably 3 Ah (ampere-hour), more preferably 4 Ah or more, and preferably 20 Ah or less, more preferably 10 Ah or less. Within the above range, the voltage drop due to electrode reaction resistance during large current draw is not too large, preventing a deterioration in power efficiency. Furthermore, the temperature distribution due to heat generation inside the battery during pulse charge and discharge is not too large, thereby avoiding phenomena such as poor durability during repeated charge and discharge, and poor heat dissipation efficiency due to sudden heat generation during abnormalities such as overcharging and internal short circuits.

[0231] (Thickness of Positive Electrode Plate) The thickness of the positive electrode plate is not particularly limited, but from the viewpoint of high capacity, high output, and high rate characteristics, the thickness of the positive electrode active material layer minus the thickness of the current collector is preferably 10 μm or more, more preferably 20 μm or more, and is preferably 200 μm or less, more preferably 150 μm or less, on one side of the current collector.

[0232] <2-1-5. Separator> In the nonaqueous electrolyte secondary battery of this embodiment, a separator is usually interposed between the positive electrode and the negative electrode to prevent short circuits. In this case, the nonaqueous electrolyte of this embodiment is usually impregnated into this separator. There are no particular restrictions on the material or shape of the separator, and any known separator can be used as long as it does not significantly impair the effects of the present invention. Among these, it is preferable to use a material that is stable with the nonaqueous electrolyte of this embodiment, such as a resin, glass fiber, or inorganic material, and that is in the form of a porous sheet or nonwoven fabric with excellent liquid retention.

[0233] Examples of materials that can be used for the resin or glass fiber separator include polyolefins such as polyethylene and polypropylene, aramid resins, polytetrafluoroethylene, polyethersulfone, and glass filters. Among these, glass filters and polyolefins are preferred, and polyolefins are even more preferred. These materials may be used alone, or two or more may be used in any combination and ratio. The thickness of the separator is optional, but is preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more, and is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less. A separator thickness within the above range provides good insulation and mechanical strength. Furthermore, deterioration of battery performance, such as rate characteristics, can be prevented, and a decrease in the energy density of the nonaqueous electrolyte secondary battery as a whole can also be prevented.

[0234] Furthermore, when a porous material such as a porous sheet or nonwoven fabric is used as the separator, the porosity of the separator is optional, but is preferably 20% or more, more preferably 35% or more, even more preferably 45% or more, and is preferably 90% or less, more preferably 85% or less, and even more preferably 75% or less. When the porosity is within the above range, the membrane resistance does not become too high, and deterioration of the rate characteristics of the secondary battery can be suppressed. Furthermore, the mechanical strength of the separator is also appropriate, and deterioration of the insulating properties can be suppressed. The average pore diameter of the separator is also optional, but is preferably 0.5 μm or less, more preferably 0.2 μm or less, and preferably 0.05 μm or more. When the average pore diameter is within the above range, short circuits are less likely to occur. Furthermore, the membrane resistance does not become too high, and deterioration of the rate characteristics of the secondary battery can be prevented.

[0235] On the other hand, inorganic materials include, for example, oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, and sulfates such as barium sulfate and calcium sulfate, and these are used in particle or fibrous form. Separators are typically in the form of thin films such as nonwoven fabrics, woven fabrics, and microporous films. Thin-film separators with pore sizes of 0.01 to 1 μm and thicknesses of 5 to 50 μm are preferably used. In addition to the independent thin-film form described above, separators can be used in which a composite porous layer containing inorganic particles is formed on the surface of the positive electrode and / or negative electrode using a resin binder. For example, a porous layer can be formed on both sides of the positive electrode using alumina particles with a 90% particle size of less than 1 μm and a fluororesin as a binder.

[0236] <2-1-6. Battery Design> (Electrode Group) The electrode group may have either a laminated structure formed by sandwiching the aforementioned positive and negative electrode plates with the aforementioned separator therebetween, or a structure formed by spirally winding the aforementioned positive and negative electrode plates with the aforementioned separator therebetween. The ratio of the volume of the electrode group to the internal volume of the battery (hereinafter referred to as the electrode group occupancy rate) is preferably 40% or more, more preferably 50% or more, and also preferably 95% or less, more preferably 90% or less. When the electrode group occupancy rate is within the above range, the battery capacity is less likely to decrease. Furthermore, since an appropriate amount of void space can be secured, it is possible to avoid a battery that, due to high temperature, expands components or increases the vapor pressure of the nonaqueous electrolyte solution, resulting in an increase in internal pressure, which can degrade various characteristics of the secondary battery, such as the charge / discharge cycle performance and high-temperature storage characteristics, and further, the activation of a gas release valve that releases internal pressure to the outside.

[0237] (Current collecting structure) The current collecting structure is not particularly limited, but in order to more effectively realize the improvement of discharge characteristics by the nonaqueous electrolyte solution of this embodiment, it is preferable to use a structure that reduces the resistance of wiring parts and joint parts. When the internal resistance is reduced in this way, the effect of using the nonaqueous electrolyte solution of this embodiment is particularly well exhibited.

[0238] When the electrode group has the aforementioned laminated structure, a structure in which the metal core portions of each electrode layer are bundled and welded to a terminal is preferably used. When the area of ​​a single electrode is large, the internal resistance increases, so it is also preferable to provide multiple terminals within the electrode to reduce the resistance. When the electrode group has the aforementioned wound structure, the internal resistance can be reduced by providing multiple lead structures on each of the positive electrode and negative electrode and bundling them to a terminal.

[0239] (Protective Element) Examples of protective elements include a PTC (Positive Temperature Coefficient) thermistor whose resistance increases when abnormal heat generation or excessive current flows, a thermal fuse, a valve (current cutoff valve) that cuts off the current flowing in the circuit due to a sudden increase in the internal pressure or temperature of the battery when abnormal heat generation occurs, etc. It is preferable to select a protective element that will not operate under normal use at high current, and it is more preferable to design a battery that will not experience abnormal heat generation or thermal runaway even without a protective element.

[0240] (Exterior Body) The nonaqueous electrolyte secondary battery of this embodiment is typically constructed by housing the above-described nonaqueous electrolyte, negative electrode, positive electrode, separator, etc., in an exterior body (exterior case). There are no limitations on this exterior body, and any known exterior body can be used as long as it does not significantly impair the effects of the present invention. The material of the exterior case is not particularly limited as long as it is a substance stable with respect to the nonaqueous electrolyte used. Specifically, metals such as nickel-plated steel sheet, stainless steel, aluminum or aluminum alloy, magnesium alloy, nickel, titanium, etc., or a laminate film (laminate film) of resin and aluminum foil are used. From the viewpoint of weight reduction, metals such as aluminum or aluminum alloy, and laminate films are preferably used.

[0241] Examples of exterior cases using the above metals include those in which the metals are welded together to form a sealed structure by laser welding, resistance welding, or ultrasonic welding, or those in which the metals are used via a resin gasket to form a crimped structure. Examples of exterior cases using the above laminate film include those in which the resin layers are heat-sealed to form a sealed structure. In order to improve sealing properties, a resin different from the resin used in the laminate film may be interposed between the resin layers. In particular, when a sealed structure is formed by heat-sealing the resin layers via a current collecting terminal, a resin having a polar group or a modified resin into which a polar group has been introduced is preferably used as the interposed resin, since the metal and resin are bonded together. The shape of the exterior case may also be arbitrary, and may be, for example, cylindrical, rectangular, laminated, coin-shaped, large, or the like.

[0242] <2-2. Nonaqueous Electrolyte Primary Battery> A nonaqueous electrolyte primary battery according to one embodiment of the present invention uses, for example, a material capable of occluding metal ions in the positive electrode and a material capable of releasing metal ions in the negative electrode. Preferred positive electrode materials are transition metal oxides such as graphite fluoride and manganese dioxide. Preferred negative electrode materials are elemental metals such as zinc and lithium. The nonaqueous electrolyte used is the nonaqueous electrolyte of this embodiment described above.

[0243] <2-3. Metal Ion Capacitor> A metal ion capacitor according to one embodiment of the present invention uses, for example, a material capable of forming an electric double layer in the positive electrode and a material capable of absorbing and releasing metal ions in the negative electrode. Activated carbon is preferred as the positive electrode material. A carbonaceous material is preferred as the negative electrode material. The nonaqueous electrolyte solution used is the nonaqueous electrolyte solution of this embodiment described above.

[0244] <2-4. Electric double layer capacitor> In an electric double layer capacitor according to one embodiment of the present invention, for example, a material capable of forming an electric double layer is used for the electrodes. Activated carbon is a preferred electrode material. The nonaqueous electrolyte solution used is the nonaqueous electrolyte solution according to this embodiment described above.

[0245] The present invention will be explained in more detail below by way of examples and reference examples, but the present invention is not limited to these examples as long as it does not depart from the gist of the invention.

[0246] <Experiment I> In Synthesis Examples 1 and 2 of this Experiment I, 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide, 2-chloro-5,5-difluoro-1,3,2-dioxaphosphorinane-2-oxide, and 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane-3,9-dioxide were synthesized according to Pharmaceutical Research (2007), 24, (4), 679-687.

[0247] The analytical methods used in the following synthesis examples are as follows: Nuclear Magnetic Resonance (NMR) Analysis １ H. １３ C. ３１ P-NMR was measured at 400, 101, and 162 MHz using a Bruker 400 Ultrashield. Samples were dissolved in deuterated chloroform or deuterated dimethyl sulfoxide (DMSOd ６ ) and measured.

[0248] [Differential scanning calorimetry (DSC)] A differential scanning calorimeter (Hitachi High-Tech Science, DSC7020) was used to measure a 1 mg sample in a nitrogen gas flow at a temperature rise rate of 10°C / min in the temperature range from 20°C to 400°C. １ and the heat generation height H at the maximum heat generation peak temperature ＭＡＸ The difference between １ and the heat generation height H １ When the calorific value is based on ΔH １ The temperature at which the temperature reached 5% of the original temperature was taken as the exothermic initiation temperature.

[0249] Synthesis Example 1 Synthesis of 2-fluoro-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide (Compound A-1) Under a nitrogen atmosphere, potassium fluoride (2.83 g, 48.9 mmol) was suspended in acetonitrile (20 mL) in a 100 mL three-necked flask equipped with a Dimroth tube. Under ice cooling, a solution of 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide (3.00 g, 16.3 mmol) in acetonitrile (10 mL) was added dropwise, and the mixture was heated to reflux for 1.5 hours. Insoluble matter was filtered off, and inorganic matter was removed using silica gel. The solvent was then distilled off to obtain the target white solid (2.36 g, 14.0 mmol). １ The purity estimated by H-NMR was 99%. The exothermic onset temperature in DSC was 242°C. １ H-NMR, １３ C-NMR, ３１ The results of the P-NMR analysis were as follows: １ H-NMR (δ, CDCl ３ ): 4.23 (2H, d, J = 10.6Hz), 4.08-3.97 (2H, m), 1.34 (3H, s), 0.92 (3H, s), １３ C-NMR (δ, CDCl ３ ): 79.2, 32.4, 21.6, 20.0, ３１ P-NMR (δ, CDCl ３ ):-16.65(J ＰＦ = 1010 Hz)

[0250] Synthesis Example 2 Synthesis of 2-fluoro-5,5-difluoro-1,3,2-dioxaphosphorinane-2-oxide (Compound A-77) In a nitrogen atmosphere, potassium fluoride (4.98 g, 83.1 mmol) was suspended in acetonitrile (60 mL) in a 300 mL three-necked flask equipped with a Dimroth tube. Under ice cooling, a solution of 2-chloro-5,5-difluoro-1,3,2-dioxaphosphorinane-2-oxide (8.61 g, 41.6 mmol) in acetonitrile (20 mL) was added dropwise, and the mixture was heated to reflux for 40 minutes. After filtering off insoluble matter, the solvent was distilled off. The crude product was purified using a Kugelrohr distillation apparatus to obtain the target white solid (1.23 g, 6.99 mmol). １The purity estimated by H-NMR was 99%. The exothermic onset temperature in DSC was 373°C. １ H-NMR, １３ C-NMR, ３１ The results of the P-NMR analysis were as follows: １ H-NMR (δ, DMSOd ６ ): 4.85-5.08 (4H, m), １３ C-NMR (δ, DMSOd ６ ): 113.23, 69.78, ３１ P-NMR (δ, DMSOd ６ ):-17.70(J ＰＦ = 1026 Hz)

[0251] Synthesis Example 3 Synthesis of 3,9-difluoro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane-3,9-dioxide (A-114) In a nitrogen atmosphere, potassium fluoride (0.780 g, 13.5 mmol) was suspended in acetonitrile (30 mL) in a 100 mL three-necked flask equipped with a Dimroth tube. Under ice cooling, 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane-3,9-dioxide (1.00 g, 3.40 mmol) was added portionwise, and the mixture was heated to reflux for 3.5 hours. After filtering off insoluble matter, inorganic salts were removed using silica gel, and the solvent was evaporated to obtain a white solid (0.390 g, 1.48 mmol). １ The purity estimated by H-NMR was 99%. The exothermic onset temperature in DSC was 204°C. １ H-NMR, ３１ The results of the P-NMR analysis were as follows: １ H NMR (δ, DMSO-d6): 4.42-4.89 (m, 8H), ３１ P NMR (δ, DMSO-d6): -17.1 (J ＰＦ = 1016 Hz)

[0252] Example 1 [Preparation of Negative Electrode] 98 parts by mass of a carbonaceous material was mixed with 1 part by mass of an aqueous dispersion of sodium carboxymethylcellulose (concentration of sodium carboxymethylcellulose: 1% by mass) and 1 part by mass of an aqueous dispersion of styrene-butadiene rubber (concentration of styrene-butadiene rubber: 50% by mass) as a thickener and binder, and the mixture was mixed in a disperser to form a slurry. The resulting slurry was applied to a 10 μm thick copper foil, dried, and rolled in a press. The resultant was cut into a shape having an active material layer size of 30 mm wide and 40 mm long, and an uncoated portion of 5 mm wide and 9 mm long to form a negative electrode.

[0253] [Preparation of Positive Electrode] LiCo was used as the positive electrode active material. ０．２ O ２ 97% by mass of the active material, 1.5% by mass of acetylene black as a conductive material, and 1.5% by mass of polyvinylidene fluoride (PVdF) as a binder were mixed in N-methylpyrrolidone solvent to form a slurry. The resulting slurry was applied to one side of a 15 μm thick aluminum foil that had previously been coated with a conductive additive, dried, and roll-pressed in a press. The resultant was cut into a shape with an active material layer size of 30 mm wide and 40 mm long, and an uncoated portion of 5 mm wide and 9 mm long to form a positive electrode.

[0254] [Preparation of non-aqueous electrolyte] In a dry argon atmosphere, dried LiPF was dissolved in a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) (volume ratio 20:80). ６ was dissolved to a concentration of 1 mol / L to prepare base electrolyte solution 1. 98 parts by mass of this base electrolyte solution 1 and 2 parts by mass of 2-fluoro-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide (compound A-1) synthesized in Synthesis Example 1 were mixed together to prepare the nonaqueous electrolyte solution of Example 1.

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[0256] [Break-in] The nonaqueous electrolyte secondary battery was sandwiched between glass plates to enhance adhesion between the electrodes, and then charged at 25°C to 4.2 V at a constant current equivalent to 0.2 C, and then discharged to 3.0 V at a constant current of 0.2 C. This was repeated for two cycles to stabilize the battery, and in the third cycle, the battery was charged to 4.2 V at a constant current of 0.2 C, then charged at a constant voltage of 4.2 V until the current value reached 0.05 C, and then discharged to 3.0 V at a constant current of 0.2 C. This was repeated for two cycles to complete the break-in.

[0257] [Evaluation of Change in Capacity Retention Rate During Repeated Charge and Discharge] Among the batteries for which the initial discharge capacity evaluation test had been completed, batteries for which both the initial output and initial input exceeded 80% were charged to 4.2 V at a constant current of 0.5 C and then discharged to 3.0 V at a constant current of 0.5 C. This cycle was repeated for 200 cycles at 25°C. The capacity retention rate (%) during repeated charge and discharge was calculated by dividing the discharge capacity at the 200th cycle by the discharge capacity at the first cycle x 100. Table 1 shows the relative value (%) when Comparative Example 1 is set to 100.0. In this example, a capacity retention rate greater than that of Comparative Example 1 was evaluated as being superior in capacity retention rate during repeated charge and discharge.

[0258] Example 2 A sheet-shaped nonaqueous electrolyte secondary battery of Example 2 was produced in the same manner as in Example 1, except that 2-fluoro-5,5-difluoro-1,3,2-dioxaphosphorinane-2-oxide (Compound A-77) synthesized in Synthesis Example 2 was used instead of Compound A-1 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0259] Comparative Example 1 A sheet-shaped nonaqueous electrolyte secondary battery of Comparative Example 1 was fabricated in the same manner as in Example 1, except that the base electrolyte 1 was used as is, and the capacity retention rate during repeated charge and discharge was evaluated.

[0260] Comparative Example 2 A sheet-shaped nonaqueous electrolyte secondary battery of Comparative Example 2 was produced in the same manner as in Example 1, except that 2-fluoro-1,3,2-dioxaphosphorinane-2-oxide was used instead of Compound A-1 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0261] Comparative Example 3 A sheet-shaped nonaqueous electrolyte secondary battery of Comparative Example 3 was produced in the same manner as in Example 1, except that diisopropyl fluorophosphate was used instead of Compound A-1 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0262] The results of Examples 1 and 2 and Comparative Examples 1 to 3 are shown in Table 1 below.

[0263] As is clear from Table 1, when the compound of this embodiment is used (Examples 1 and 2), the capacity retention rate during repeated charge and discharge is superior to when base electrolyte 1 is used as is (Comparative Example 1) or when a non-cyclic phosphorus compound (Comparative Example 3) is used. Furthermore, the compounds of this embodiment (Examples 1 and 2) exhibit a higher heat generation initiation temperature than a phosphorus compound that has a cyclic structure but does not have two substituents at the 5-position (Comparative Example 2), and therefore have excellent industrial thermal stability. It can be seen that it is important to select a compound represented by general formula (A1) or (A2) as a compound with high industrial thermal stability that contributes to improving the capacity retention rate during repeated charge and discharge.

[0264] Example 3 [Preparation of Negative Electrode] 98 parts by mass of a carbonaceous material was mixed with 1 part by mass of an aqueous dispersion of sodium carboxymethylcellulose (concentration of sodium carboxymethylcellulose: 1% by mass) and 1 part by mass of an aqueous dispersion of styrene-butadiene rubber (concentration of styrene-butadiene rubber: 50% by mass) as a thickener and binder, and the mixture was mixed in a disperser to form a slurry. The resulting slurry was applied to a 10 μm thick copper foil, dried, and rolled in a press. The resultant was cut into a shape having an active material layer size of 30 mm wide and 40 mm long, and an uncoated portion of 5 mm wide and 9 mm long to form a negative electrode.

[0265] [Preparation of Positive Electrode] 97% by mass of LiCoO2 as a positive electrode active material, 1.5% by mass of acetylene black as a conductive material, and 1.5% by mass of polyvinylidene fluoride (PVdF) as a binder were mixed in N-methylpyrrolidone solvent to form a slurry. The obtained slurry was applied to one side of a 15 μm thick aluminum foil that had previously been coated with a conductive additive, dried, and roll-pressed in a press. The active material layer was cut into a shape with a width of 30 mm, a length of 40 mm, and an uncoated portion of 5 mm and a length of 9 mm to form a positive electrode.

[0266] [Preparation of Non-Aqueous Electrolyte Solution] Under a dry argon atmosphere, dried LiPF6 was dissolved in a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) (volume ratio 20:80) to a concentration of 1 mol / L to prepare a basic electrolyte solution 1. 100 parts by mass of this basic electrolyte solution 1 and 2 parts by mass of 2-fluoro-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide (compound A-1) synthesized in Synthesis Example 1 were mixed to prepare a non-aqueous electrolyte solution of Example 3.

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[0268] [Break-in] The non-aqueous electrolyte secondary battery was sandwiched between glass plates to enhance adhesion between the electrodes, and then charged at a constant current equivalent to 0.05 C for 6 hours at 25 ° C., and then discharged to 3.0 V at a constant current of 0.2 C. After charging to 4.1 V at a constant current equivalent to 0.2 C, charging was carried out at a constant voltage of 4.1 V until the current value reached 0.05 C, and the battery was left standing at 45 ° C. for 72 hours, and then discharged to 3.0 V at a constant current of 0.2 C. After that, charging to 4.2 V at a constant current of 0.2 C, charging was carried out at a constant voltage of 4.2 V until the current value reached 0.05 C, and then discharging to 3.0 V at a constant current of 0.2 C to complete the break-in operation.

[0269] [Evaluation of Changes in Capacity Retention Rate During Repeated Charge and Discharge] Among the batteries that had undergone the initial discharge capacity evaluation test, those with initial output and initial input both exceeding 80% were selected. They were charged to 4.2 V at a constant current of 0.5 C, then charged at a constant voltage of 4.2 V until the current reached 0.05 C, and then discharged at a constant current of 0.5 C to 3.0 V. This cycle was repeated for 300 cycles at 25°C. In the first cycle and every 100 cycles thereafter, the batteries were charged to 4.2 V at a constant current of 0.2 C, then charged at a constant voltage of 4.2 V until the current reached 0.05 C, and then discharged at a constant current of 0.2 C to 3.0 V. The capacity retention rate (%) during repeated charge and discharge was calculated by dividing the discharge capacity at the 300th cycle by the discharge capacity at the first cycle × 100. Table 2 shows the relative values ​​(%) when Comparative Example 4 is set to 100.0. In this example, a battery with a higher capacity retention rate than Comparative Example 4 was evaluated as having excellent capacity retention rate during repeated charge and discharge.

[0270] Example 4 A sheet-shaped nonaqueous electrolyte secondary battery of Example 4 was produced in the same manner as in Example 3, except that 2-fluoro-5,5-difluoro-1,3,2-dioxaphosphorinane-2-oxide (Compound A-77) synthesized in Synthesis Example 2 was used instead of Compound A-1 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0271] Example 5 A sheet-like nonaqueous electrolyte secondary battery of Example 5 was produced in the same manner as in Example 3, except that 3,9-difluoro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane-3,9-dioxide (Compound A-114) synthesized in Synthesis Example 3 was used instead of Compound A-1 in preparing the nonaqueous electrolyte, and the capacity retention rate during repeated charge and discharge was evaluated.

[0272] Comparative Example 4 A sheet-shaped nonaqueous electrolyte secondary battery of Comparative Example 4 was produced in the same manner as in Example 3, except that the base electrolyte 1 was used as is, and the capacity retention rate during repeated charge and discharge was evaluated.

[0273] Comparative Example 5 A sheet-shaped nonaqueous electrolyte secondary battery of Comparative Example 5 was produced in the same manner as in Example 3, except that 2-fluoro-1,3,2-dioxaphosphorinane-2-oxide was used instead of Compound A-1 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0274] Comparative Example 6 A sheet-shaped nonaqueous electrolyte secondary battery of Comparative Example 5 was produced in the same manner as in Example 3, except that 2-fluoro-5-methyl-1,3,2-dioxaphosphorinane-2-oxide was used instead of Compound A-1 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0275] Comparative Example 7 A sheet-shaped nonaqueous electrolyte secondary battery of Comparative Example 7 was produced in the same manner as in Example 3, except that diisopropyl fluorophosphate was used instead of Compound A-1 in preparing the nonaqueous electrolyte, and the capacity retention rate during repeated charge and discharge was evaluated.

[0276] The results of Examples 3 to 5 and Comparative Examples 4 to 7 are shown in Table 2 below.

[0277] As is clear from Table 2, when the compound of this embodiment is used (Examples 3 to 5), the capacity retention rate during repeated charge and discharge is superior to when base electrolyte 1 is used as is (Comparative Example 4) or when a non-cyclic phosphorus compound (Comparative Example 7) is used. Furthermore, the compounds of this embodiment (Examples 3 to 5) exhibit a higher heat generation initiation temperature than phosphorus compounds that have a cyclic structure but do not have two substituents at the 5-position (Comparative Examples 5 and 6), and therefore have excellent industrial thermal stability. It can be seen that it is important to select a compound represented by general formula (A1) or (A2) as a compound with high industrial thermal stability that contributes to improving the capacity retention rate during repeated charge and discharge.

[0278] (Example 6) [Fabrication of Negative Electrode] Natural graphite powder as the negative electrode active material, an aqueous dispersion of sodium carboxymethyl cellulose (concentration of sodium carboxymethyl cellulose: 1% by mass) and an aqueous dispersion of styrene-butadiene rubber (concentration of styrene-butadiene rubber: 50% by mass) as the thickener and binder, respectively, were mixed in a disperser to form a slurry. This slurry was uniformly applied to one side of a 10 μm thick copper foil, dried, and then pressed to form a negative electrode. The negative electrode was fabricated so that the mass ratio of natural graphite:sodium carboxymethyl cellulose:styrene-butadiene rubber after drying was 98:1:1.

[0279] [Preparation of Positive Electrode] 90% by mass of lithium-nickel-manganese-cobalt composite oxide (NMC) as the positive electrode active material, 7% by mass of acetylene black as the conductive material, and 3% by mass of polyvinylidene fluoride (PVdF) as the binder were mixed in N-methylpyrrolidone solvent to form a slurry. The resulting slurry was applied to both sides of a 15 μm thick aluminum foil that had previously been coated with a conductive additive, dried, and pressed to form a positive electrode.

[0280] [Preparation of non-aqueous electrolyte] In a dry argon atmosphere, dried LiPF was dissolved in a mixture of ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (volume ratio: 30:40:30). ６was dissolved to a concentration of 1 mol / L to prepare base electrolyte solution 2. 97.5 parts by mass of this base electrolyte solution 2, 2.0 parts by mass of vinylene carbonate, and 0.5 parts by mass of 2-fluoro-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide (compound A-1) synthesized in Synthesis Example 1 were mixed together to prepare the nonaqueous electrolyte solution of Example 6.

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[0282] [Break-in] The nonaqueous electrolyte secondary battery was sandwiched between glass plates to enhance adhesion between the electrodes, and then charged to 3.7 V at a constant current equivalent to 0.05 C at 25 ° C., and then discharged to 2.8 V at a constant current of 0.2 C. Next, the battery was charged to 4.1 V at a constant current of 0.2 C, and then charged at a constant voltage of 4.1 V until the current value reached 0.05 C, and then left to stand at 45 ° C. for 24 hours. The break-in was then completed by discharging to 2.8 V at a constant current of 0.2 C.

[0283] [Evaluation of Change in Capacity Retention Rate During Repeated Charge and Discharge] Batteries for which the initial discharge capacity evaluation test had been completed were charged to 4.2 V at a constant current of 1 C, discharged to 3.0 V at a constant current of 1 C, and then discharged at a low voltage of 3.0 V until the constant current reached 0.1 C. This cycle was repeated for 200 cycles at 45°C. The capacity retention rate (%) during repeated charge and discharge was calculated by dividing the discharge capacity at the 200th cycle by the discharge capacity at the first cycle x 100. Table 3 shows the relative value (%) when Comparative Example 8 is set to 100.0. In this example, a capacity retention rate greater than that of Comparative Example 8 was evaluated as being excellent in the capacity retention rate during repeated charge and discharge.

[0284] Example 7 A sheet-like nonaqueous electrolyte secondary battery of Example 7 was produced in the same manner as in Example 6, except that 3,9-difluoro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane-3,9-dioxide (Compound A-114) synthesized in Synthesis Example 3 was used instead of Compound A-1 in preparing the nonaqueous electrolyte, and the capacity retention rate during repeated charge and discharge was evaluated.

[0285] Comparative Example 8 A sheet-shaped nonaqueous electrolyte secondary battery of Comparative Example 8 was produced in the same manner as in Example 6, except that the base electrolyte 2 was used as is, and the capacity retention rate during repeated charge and discharge was evaluated.

[0286] The results of Examples 6 and 7 and Comparative Example 8 are shown in Table 3 below.

[0287] As is clear from Table 3, when the compound of this embodiment is used (Examples 6 to 7), the capacity retention rate during repeated charge and discharge is superior to when base electrolyte solution 2 is used as is (Comparative Example 8). Furthermore, the compounds of this embodiment (Examples 6 to 7) exhibit a high heat generation onset temperature, and therefore have excellent industrial thermal stability. It can be seen that it is important to select a compound represented by general formula (A1) or (A2) as a compound with high industrial thermal stability that contributes to improving the capacity retention rate during repeated charge and discharge.

[0288] Example 8 Preparation of Non-Aqueous Electrolyte Solution In a dry argon atmosphere, dried LiPF 6 was dissolved in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (volume ratio 30:70). ６ was dissolved to a concentration of 1 mol / L to prepare base electrolyte solution 3. 100 parts by mass of this base electrolyte solution 3 and 1.9 parts by mass of 2-fluoro-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide (compound A-1) synthesized in Synthesis Example 1 were mixed together to prepare the nonaqueous electrolyte solution of Example 8.

[0289] [Fabrication of Non-Aqueous Electrolyte Secondary Battery] A SiO thin film formed by sputtering SiO on a copper foil, metallic lithium, a non-aqueous electrolyte, and a polyethylene separator were laminated in this order: SiO thin film, non-aqueous electrolyte, separator, metallic lithium. The battery element thus obtained was placed in a 2032 coin battery can and crimped with a crimping machine to prepare a coin-type non-aqueous electrolyte secondary battery of Example 8.

[0290] [Break-in] The nonaqueous electrolyte secondary battery was charged at 25°C to 5 mV at a constant current equivalent to 0.05 C, then charged at a constant voltage of 5 mV until the current value reached 0.01 C, and then discharged to 1500 mV at a constant current of 0.1 C. This cycle was repeated three times to stabilize the battery and complete the break-in.

[0291] [Evaluation of Capacity Retention Rate During Repeated Charge and Discharge] After the break-in period, the battery was charged to 5 mV at a constant current equivalent to 0.05 C, then charged at a constant voltage of 5 mV until the current reached 0.01 C, and then discharged at a constant current of 0.1 C until the current reached 1500 mV. This discharge amount was recorded as the discharge capacity at the first cycle. Subsequently, charging to 5 mV and discharging to 1500 mV were repeated 150 times. Charge and discharge were performed under the above conditions once every 30 cycles. The remaining cycles were charged to 5 mV at a constant current equivalent to 0.5 C, then charged at a constant voltage of 5 mV until the current reached 0.05 C, and then discharged at a constant current of 1 C until the current reached 1500 mV. The discharge amount at 0.1 C at the 151st cycle was recorded as the discharge capacity at the 151st cycle. The capacity retention rate (%) during repeated charge and discharge was calculated by dividing the discharge capacity at the 151st cycle by the discharge capacity at the 1st cycle × 100.

[0292] Example 9 A coin-shaped nonaqueous electrolyte secondary battery of Example 9 was produced in the same manner as in Example 8, except that 2.0 parts by mass of 2-fluoro-5,5-difluoro-1,3,2-dioxaphosphorinane-2-oxide (Compound A-77) synthesized in Synthesis Example 2 was used instead of Compound A-1 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0293] Example 10 A coin-shaped nonaqueous electrolyte secondary battery of Example 10 was produced in the same manner as in Example 8, except that 3.0 parts by mass of 3,9-difluoro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane-3,9-dioxide (Compound A-114) synthesized in Synthesis Example 3 was used instead of Compound A-1 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0294] Comparative Example 9 A coin-type nonaqueous electrolyte secondary battery of Comparative Example 9 was fabricated in the same manner as in Example 8, except that the base electrolyte 3 was used as is, and the capacity retention rate during repeated charge and discharge was evaluated.

[0295] Comparative Example 10 A coin-type nonaqueous electrolyte secondary battery of Comparative Example 10 was produced in the same manner as in Example 8, except that 1.6 parts by mass of 2-fluoro-1,3,2-dioxaphosphorinane-2-oxide was used instead of Compound A-1 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0296] Comparative Example 11 A coin-type nonaqueous electrolyte secondary battery of Comparative Example 11 was produced in the same manner as in Example 8, except that 1.8 parts by mass of 2-fluoro-5-methyl-1,3,2-dioxaphosphorinane-2-oxide was used instead of Compound A-1 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0297] Comparative Example 12 A coin-shaped nonaqueous electrolyte secondary battery of Comparative Example 12 was produced in the same manner as in Example 8, except that 2.1 parts by mass of diisopropyl fluorophosphate was used instead of Compound A-1 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0298] Comparative Example 13 A coin-type nonaqueous electrolyte secondary battery of Comparative Example 13 was produced in the same manner as in Example 8, except that 0.9 parts by mass of triethyl phosphate was used instead of Compound A-1, and the capacity retention rate during repeated charge and discharge was evaluated.

[0299] The results of Examples 8 to 10 and Comparative Examples 9 to 13 are shown in Table 4. The evaluation of the capacity retention rate during repeated charge and discharge is shown as a relative value (%) when the value of Comparative Example 9 is set to 100.

[0300]

[0301] As is clear from Table 4, when the compound of this embodiment is used (Examples 8 to 10), the capacity retention rate during repeated charge and discharge is superior to when base electrolyte 3 is used as is (Comparative Example 9) or when acyclic phosphorus compounds (Comparative Examples 12 to 13) are used. Furthermore, the general formula compounds of this embodiment (Examples 8 to 10) exhibit a higher heat generation initiation temperature than cyclic phosphorus compounds (Comparative Examples 10 to 11) that do not have two substituents at the 5-position, and therefore have excellent industrial thermal stability. It can be seen that it is important to select a compound represented by general formula (A1) or (A2) as a compound with high industrial thermal stability that contributes to improving the capacity retention rate during repeated charge and discharge.

[0302] <Experiment II> In this Experiment II, 2-fluoro-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide (Compound B-34), 2-fluoro-5,5-difluoro-1,3,2-dioxaphosphorinane-2-oxide (Compound B-22), and 3,9-difluoro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane-3,9-dioxide (Compound B-58) were used which were synthesized in the same manner as in Synthesis Examples 1 to 3 in Experiment I. 2-Fluoro-1,3,2-dioxaphosphorinane-2-oxide (Compound B-5) and 2-fluoro-5-methyl-1,3,2-dioxaphosphorinane-2-oxide (Compound B-30) were synthesized according to Phosphorus and Sulfur and the Related Elements (1981), 11, 19-25.

[0303] Example 11 [Preparation of non-aqueous electrolyte] In a dry argon atmosphere, dried LiPF was dissolved in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (volume ratio 30:70). ６A base electrolyte solution was prepared by dissolving the above in an amount of 1 mol / L. 1.9 parts by mass of 2-fluoro-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-oxide (compound B-34) was mixed with this base electrolyte solution 3 to prepare a nonaqueous electrolyte solution of Example 11.

[0304] [Production of non-aqueous electrolyte secondary battery] ｘ Sputtered SiO ｘ A thin film (x=1.3), metallic lithium, a non-aqueous electrolyte solution, and a polyethylene separator were mixed with SiO ｘ The thin film, the nonaqueous electrolyte, the separator, and metallic lithium were laminated in this order, and the battery element thus obtained was placed in a 2032 coin battery can and crimped with a crimping machine to prepare a coin-type nonaqueous electrolyte secondary battery of Example 11.

[0305] [Break-in] The lithium secondary battery was charged at 25°C to 5 mV at a constant current equivalent to 0.05 C, then charged at a constant voltage of 5 mV until the current value reached 0.01 C, and then discharged to 1500 mV at a constant current of 0.1 C. This cycle was repeated three times to stabilize the battery and complete the break-in.

[0306] [Evaluation of Capacity Retention Rate During Repeated Charge and Discharge] After the break-in period, the battery was charged to 5 mV at a constant current equivalent to 0.05 C, then charged at a constant voltage of 5 mV until the current reached 0.01 C, and then discharged at a constant current of 0.1 C until the current reached 1500 mV. This discharge amount was recorded as the discharge capacity at the first cycle. Subsequently, charging to 5 mV and discharging to 1500 mV were repeated 150 times. Charge and discharge were performed under the above conditions once every 30 cycles. The remaining cycles were charged to 5 mV at a constant current equivalent to 0.5 C, then charged at a constant voltage of 5 mV until the current reached 0.05 C, and then discharged at a constant current of 1 C until the current reached 1500 mV. The discharge amount at 0.1 C at the 151st cycle was recorded as the discharge capacity at the 151st cycle. The discharge capacity retention rate (%) during repeated charge and discharge was calculated by (discharge capacity at the 151st cycle) ÷ (discharge capacity at the 1st cycle) × 100. Table 5 shows the relative values ​​(%) when Comparative Example 14 is set to 100.0.

[0307] Example 12 A coin-shaped nonaqueous electrolyte secondary battery of Example 12 was produced in the same manner as in Example 11, except that 2.0 parts by mass of 2-fluoro-5,5-difluoro-1,3,2-dioxaphosphorinane-2-oxide (Compound B-22) was used instead of Compound B-34 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0308] Example 13 A coin-shaped nonaqueous electrolyte secondary battery of Example 13 was produced in the same manner as in Example 11, except that 3.0 parts by mass of 3,9-difluoro-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane-3,9-dioxide (Compound B-58) was used instead of Compound B-34 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0309] Example 14 A coin-shaped nonaqueous electrolyte secondary battery of Example 14 was produced in the same manner as in Example 11, except that 1.6 parts by mass of 2-fluoro-1,3,2-dioxaphosphorinane-2-oxide (Compound B-5) was used instead of Compound B-34 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0310] Example 15 A coin-shaped nonaqueous electrolyte secondary battery of Example 15 was produced in the same manner as in Example 11, except that 1.8 parts by mass of 2-fluoro-5-methyl-1,3,2-dioxaphosphorinane-2-oxide (Compound B-30) was used instead of Compound B-34 in preparing the nonaqueous electrolyte solution, and the capacity retention rate during repeated charge and discharge was evaluated.

[0311] (Comparative Example 14) A coin-shaped nonaqueous electrolyte secondary battery of Comparative Example 14 was produced in the same manner as in Example 11, except that base electrolyte solution 3 was used as is, and the cycle characteristics were evaluated. (Comparative Example 15) A coin-shaped nonaqueous electrolyte secondary battery of Comparative Example 15 was produced in the same manner as in Example 11, except that 2.1 parts by mass of diisopropyl fluorophosphate was used instead of compound B-34, and the cycle characteristics were evaluated.

[0312] Comparative Example 16 A coin-type nonaqueous electrolyte secondary battery of Comparative Example 16 was produced in the same manner as in Example 11, except that 0.9 parts by mass of triethyl phosphate was used instead of compound B-34, and the cycle characteristics were evaluated.

[0313] The results of Examples 11 to 15 and Comparative Examples 14 to 16 are shown in Table 5. The evaluation of the capacity retention rate during repeated charge and discharge is shown as a relative value (%) when the value of Comparative Example 14 is set to 100.

[0314] As is clear from Table 5, in non-aqueous secondary batteries having a negative electrode active material containing silicon atoms in the negative electrode, when a compound represented by general formula (B1) or (B2) was used (Examples 11 to 15), the capacity retention rate during repeated charge and discharge was superior to when the basic electrolyte solution was used as is (Comparative Example 14) or when an acyclic phosphorus compound was used (Comparative Examples 15 to 16). It can be seen that it is important to select a compound represented by general formula (B1) or (B2).

[0315] According to the first aspect of the nonaqueous electrolyte solution of this embodiment, it can be handled industrially stably and can improve the capacity retention rate of nonaqueous electrolyte secondary batteries during repeated charge and discharge. According to the second aspect, it can improve the capacity retention rate of nonaqueous electrolyte secondary batteries during repeated charge and discharge. Both aspects are useful. Therefore, the nonaqueous electrolyte solution of this embodiment and energy devices such as nonaqueous electrolyte secondary batteries using the same can be used in a variety of known applications. Specific examples include laptops, pen-input PCs, mobile PCs, e-book players, mobile phones, mobile fax machines, mobile copiers, mobile printers, headphone stereos, video movie players, LCD TVs, handheld vacuum cleaners, portable CD players, minidiscs, transceivers, electronic organizers, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, automobiles, motorcycles, mopeds, bicycles, lighting equipment, toys, game equipment, watches, power tools, flash devices, cameras, home backup power supplies, business backup power supplies, load-leveling power supplies, natural energy storage power supplies, and lithium ion capacitors.

Claims

1. A non-aqueous electrolyte containing a compound represented by the following general formula (A1) and / or (A2). (In formula (A2), X ２ and X ３ are each independently a halogen atom. R ７ to R １４ each independently represent a hydrogen atom, a halogen atom, or a hydrocarbon group having 10 or fewer carbon atoms which may be substituted by a halogen atom. Incidentally, R ７ to R １４ may combine to form a ring.) 2. In the formula (A1), R １ , R ２ , R ５ , and R ６ are hydrogen atoms, the non-aqueous electrolyte according to claim 1.

3. X in the formula (A1) １ The non-aqueous electrolyte according to claim 1 or 2, wherein is a fluorine atom.

4. R of the formula (A2) ７ ~R １４ The non-aqueous electrolyte according to claim 1, wherein all are hydrogen atoms.

5. X of the formula (A2) ２ , and X ３ is a fluorine atom, the non-aqueous electrolyte according to claim 1 or 4.

6. The non-aqueous electrolyte according to any one of claims 1 to 5, containing at least one organic solvent selected from the group consisting of a saturated cyclic carbonate, a chain carbonate, a chain carboxylic acid ester, a cyclic carboxylic acid ester, an ether compound, and a sulfone compound.

7. The non-aqueous electrolyte according to any one of claims 1 to 6, wherein the total content of the compounds represented by the general formulas (A1) and (A2) is 0.001% by mass or more and 30% by mass or less based on the total amount of the non-aqueous electrolyte.

8. An energy device comprising a plurality of electrodes capable of occluding and releasing metal ions and the non-aqueous electrolyte according to any one of claims 1 to 7.

9. A compound represented by the following formula (A3).

10. An energy device comprising a positive electrode capable of occluding and releasing metal ions, a negative electrode capable of occluding and releasing metal ions, and a non-aqueous electrolyte, wherein the negative electrode contains a negative electrode active material containing silicon atoms, and the non-aqueous electrolyte is a non-aqueous electrolyte containing at least one selected from compounds represented by the following general formulas (B1) and (B2). (In general formula (B2), X ２ ’ and X ３ ’ are each independently a halogen atom, and Z represents a tetravalent alkyl group having 4 to 8 carbon atoms that forms a ring together with a part of a halogenated phosphate ester. However, the hydrogen atoms of the carbon atoms constituting the ring in Z may be substituted with halogen atoms or organic groups having 6 or less carbon atoms.) 11. The energy device according to claim 10, wherein in Y of the general formula (B1), the number of carbon atoms constituting the ring together with a part of the phosphoric acid ester halide is 3.

12. The energy device according to claim 10 or 11, wherein at least one of the hydrogen atoms of the carbon constituting the ring in Y of the general formula (B1) is substituted with a fluorine atom.

13. X in the general formula (B1) １ ’ is a fluorine atom, and the energy device according to any one of claims 10 to 12.

14. The energy device according to claim 10, wherein in Z of the general formula (B2), the number of carbon atoms constituting the ring together with a part of the phosphoric acid ester halide is 5.

15. The energy device according to claim 14, wherein at least one of the hydrogen atoms of the carbon constituting the ring in Z of the general formula (B2) is substituted with a fluorine atom.

16. X of the general formula (B2) ２ ’ and X ３ ’ are fluorine atoms, and the energy device according to any one of claims 10, 14, and 15.

17. The energy device according to any one of claims 10 to 16, wherein the non-aqueous electrolyte contains at least one compound selected from the group consisting of a saturated cyclic carbonate, a chain carbonate, a chain carboxylic acid ester, a cyclic carboxylic acid ester, an ether compound, and a sulfone compound.

18. The energy device according to any one of claims 10 to 17, wherein the total content of the compounds represented by the general formulas (B1) and (B2) is 0.001% by mass or more and 30% by mass or less based on the total amount of the non-aqueous electrolyte.