Non-aqueous solutions, retention methods, and non-aqueous batteries

Abstract

The present disclosure provides a non-aqueous solution that comes into contact with an austenitic stainless steel. The non-aqueous solution contains a non-aqueous solvent or solvents and an imidic acid represented by a specified structure or a salt of the imidic acid, in which the content of a non-aqueous solvent having a relative permittivity of 10 or less (at 25°C) in the non-aqueous solvent or solvents is 50 to 100% by volume.

Description

[Technical Field]

[0001] This disclosure relates to non-aqueous solutions, retention methods, and non-aqueous batteries. [Background technology]

[0002] Patent Document 1 discloses a lithium-ion secondary battery comprising an electrode composite layer containing an electrode active material and an organic ferroelectric material having a relative permittivity of 25 or more, and an electrolyte containing lithium-bis(fluorosulfonyl)imide and a non-aqueous solvent, wherein the content of the organic ferroelectric material is 0.5 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the electrode active material, and the proportion of the non-aqueous solvent that is a highly polar solvent having a relative permittivity of 10 or more is 10% by volume or less, thereby improving the output characteristics.

[0003] On the other hand, various imido acids having a phosphoryl group, such as bis(phosphoryl)imide (HN(POX2)2) and asymmetric phosphorylimide (HN(POX2)(SO2X)), as well as their metal salts and onium salts, have recently been known to be useful as ion-conducting materials, anion sources for ionic liquids, electrolytes and additives for non-aqueous electrolyte batteries such as lithium-ion batteries, lithium batteries, lithium-ion capacitors, and sodium-ion batteries (Patent Documents 2 and 3).

[0004] Non-patent document 1 describes a method for synthesizing [bis(difluorophosphoryl)imide]lithium salt. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2016-164832 [Patent Document 2] Japanese Patent Application Publication No. 2010-254554 [Patent Document 3] Chinese Patent Publication Number CN102617414A [Non-patent literature]

[0006] [Non-Patent Document 1] Z.Anorg.Allg.Chem.412(1),65-70(1975) [Overview of the project] [Problems that the invention aims to solve]

[0007] The inventors have discovered that non-aqueous solutions or non-aqueous electrolytes of imido acids or imido salts with a specific structure containing a phosphoryl group are prone to causing corrosion when brought into contact with austenitic stainless steel, depending on the type of solvent. Therefore, the object of this disclosure is to provide a non-aqueous solution that is less likely to cause corrosion even when in contact with austenitic stainless steel, a method for holding the same, and a non-aqueous battery that is less likely to cause corrosion to austenitic stainless steel even if it is included as a wetted component. [Means for solving the problem]

[0008] In view of the above problems, the present inventors conducted diligent studies and found that even in non-aqueous solutions or non-aqueous electrolytes of imido acids or imido salts having a specific structure containing a phosphoryl group, corrosion when in contact with austenitic stainless steel can be suppressed by including a predetermined amount of a specific solvent, leading to this disclosure.

[0009] In other words, this disclosure includes the following embodiments.

[0010] [1] A non-aqueous solution in contact with austenitic stainless steel, The aforementioned non-aqueous solution comprises a non-aqueous solvent and an imid acid or imidate salt represented by the following general formula [1], A non-aqueous solution in which the non-aqueous solvent having a relative permittivity (at 25°C) of 10 or less is present in an amount of 50 to 100% by volume.

[0011] [ka]

[0012] [In general formula [1], X 1 , X 2 Each of these independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and at least one of the following can be present in the organic group: a fluorine atom, an oxygen atom, a nitrogen atom, and an unsaturated bond. Z represents -P(=O)<, -S(=O)²-, or -C(=O)-. a is either 0 or 1. When Z represents -P(=O)<, a is 1; when Z represents -S(=O)²- or -C(=O)-, a is 0. R 1 , R 2 Each of these independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkenyl group, a C2-C10 alkenyloxy group, a C2-C10 alkynyl group, a C2-C10 alkynyloxy group, a C3-C10 cycloalkyl group, a C3-C10 cycloalkoxy group, a C3-C10 cycloalkenyl group, a C3-C10 cycloalkenyloxy group, a C6-C10 aryl group, and a C6-C10 aryloxy group, and the organic group may also contain at least one selected from a fluorine atom, an oxygen atom, and an unsaturated bond. M m+ [where m represents a proton, alkali metal cation, alkaline earth metal cation, or onium cation, and m represents the valency of the cation.]

[0013] [2] The non-aqueous solution according to [1], wherein the non-aqueous solvent having a relative permittivity of 10 or less (at 25°C) is at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, methyl acetate, ethyl acetate, ethyl propionate, 1,2-dimethoxyethane, and diethylene glycol dimethyl ether.

[0014] [3] The non-aqueous solution according to [1] or [2], wherein the concentration of the imid acid or imidate salt represented by the general formula [1] in the non-aqueous solution is 1 to 90% by mass.

[0015] [4] A method for holding a non-aqueous solution in a wetted member, including an austenitic stainless steel, The aforementioned non-aqueous solution comprises a non-aqueous solvent and an imid acid or imidate salt represented by the following general formula [1], A storage method wherein the non-aqueous solvent has a relative permittivity of 10 or less (at 25°C) and its content in the non-aqueous solvent is 50 to 100% by volume.

[0016] [ka]

[0017] [In general formula [1], X 1 , X 2 Each of these independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and at least one of the following can be present in the organic group: a fluorine atom, an oxygen atom, a nitrogen atom, and an unsaturated bond. Z represents -P(=O)<, -S(=O)²-, or -C(=O)-. a is either 0 or 1. When Z represents -P(=O)<, a is 1; when Z represents -S(=O)²- or -C(=O)-, a is 0. R1 , R 2 is, independently of each other, a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and at least one selected from a fluorine atom, an oxygen atom, and an unsaturated bond may be present in the organic group. M m+ represents a proton, an alkali metal cation, an alkaline earth metal cation, or an onium cation, and m represents the valence of the cation.

[0018] [5] The non-aqueous solvent having a relative permittivity of 10 or less (at 25°C) is at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, methyl acetate, ethyl acetate, ethyl propionate, 1,2-dimethoxyethane, and diethylene glycol dimethyl ether, and the holding method according to [4].

[0019] [6] The concentration of the imidic acid or imidic acid salt represented by the general formula [1] in the non-aqueous solution is 1 to 90% by mass, and the holding method according to [4] or [5].

[0020] [7] A non-aqueous battery including a liquid contact member containing austenitic stainless steel and a non-aqueous electrolyte contacting the liquid contact member, The non-aqueous electrolyte contains a non-aqueous solvent and an imidic acid or imidic acid salt represented by the following general formula [1], A non-aqueous battery in which the content of a non-aqueous solvent having a relative permittivity (at 25°C) of 10 or less in the non-aqueous solvent is 50 to 100% by volume.

[0021] [ka]

[0022] [In general formula [1], X 1 , X 2 Each of these independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and at least one of the following can be present in the organic group: a fluorine atom, an oxygen atom, a nitrogen atom, and an unsaturated bond. Z represents -P(=O)<, -S(=O)²-, or -C(=O)-. a is either 0 or 1. When Z represents -P(=O)<, a is 1; when Z represents -S(=O)²- or -C(=O)-, a is 0. R 1 , R 2 Each of these independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkenyl group, a C2-C10 alkenyloxy group, a C2-C10 alkynyl group, a C2-C10 alkynyloxy group, a C3-C10 cycloalkyl group, a C3-C10 cycloalkoxy group, a C3-C10 cycloalkenyl group, a C3-C10 cycloalkenyloxy group, a C6-C10 aryl group, and a C6-C10 aryloxy group, and the organic group may also contain at least one selected from a fluorine atom, an oxygen atom, and an unsaturated bond. M m+ [where m represents a proton, alkali metal cation, alkaline earth metal cation, or onium cation, and m represents the valency of the cation.]

[0023] [8] The non-aqueous battery according to [7], wherein the non-aqueous solvent having a relative permittivity of 10 or less (at 25°C) is at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, methyl acetate, ethyl acetate, ethyl propionate, 1,2-dimethoxyethane, and diethylene glycol dimethyl ether.

[0024] [9] The non-aqueous battery according to [7] or [8], wherein the concentration of the imid acid or imidate salt represented by the general formula [1] in the non-aqueous electrolyte is 0.1 to 10% by mass. [Effects of the Invention]

[0025] This disclosure provides a non-aqueous solution that is less likely to cause corrosion even when in contact with austenitic stainless steel, a method for holding the same, and a non-aqueous battery that is less likely to cause corrosion to austenitic stainless steel even if it is included as a wetted component. [Modes for carrying out the invention]

[0026] The present disclosure will be described in detail below, but the description of the constituent elements described below is an example of an embodiment of the present disclosure and is not limited to these specific contents. It can be implemented in various ways within the scope of its gist.

[0027] The first disclosure is a non-aqueous solution in contact with austenitic stainless steel, The aforementioned non-aqueous solution comprises a non-aqueous solvent and an imid acid or imidate salt represented by the following general formula [1], This invention relates to a non-aqueous solution in which the non-aqueous solvent having a relative permittivity (at 25°C) of 10 or less is present in a volume of 50 to 100%.

[0028] [ka]

[0029] [In general formula [1], X 1 , X2 Each of these independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and at least one of the following can be present in the organic group: a fluorine atom, an oxygen atom, a nitrogen atom, and an unsaturated bond. Z represents -P(=O)<, -S(=O)²-, or -C(=O)-. a is either 0 or 1. When Z represents -P(=O)<, a is 1; when Z represents -S(=O)²- or -C(=O)-, a is 0. R 1 , R 2 Each of these independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkenyl group, a C2-C10 alkenyloxy group, a C2-C10 alkynyl group, a C2-C10 alkynyloxy group, a C3-C10 cycloalkyl group, a C3-C10 cycloalkoxy group, a C3-C10 cycloalkenyl group, a C3-C10 cycloalkenyloxy group, a C6-C10 aryl group, and a C6-C10 aryloxy group, and the organic group may also contain at least one selected from a fluorine atom, an oxygen atom, and an unsaturated bond. M m+ [where m represents a proton, alkali metal cation, alkaline earth metal cation, or onium cation, and m represents the valency of the cation.]

[0030] A second disclosure relates to a method for holding a non-aqueous solution in a wetted member, including an austenitic stainless steel, The non-aqueous solution comprises a non-aqueous solvent and an imidic acid or imidate represented by the above general formula [1], The present invention relates to a retention method wherein the non-aqueous solvent having a relative permittivity of 10 or less (at 25°C) contains 50 to 100% by volume.

[0031] Furthermore, the third disclosure relates to a non-aqueous battery comprising a wetted member including austenitic stainless steel, and a non-aqueous electrolyte in contact with the wetted member, The non-aqueous electrolyte comprises a non-aqueous solvent and an imid acid or imidate salt represented by the above general formula [1], This invention relates to a non-aqueous battery in which the non-aqueous solvent having a relative permittivity (at 25°C) of 10 or less is present in a volume of 50 to 100%.

[0032] The first non-aqueous solution according to the present disclosure comprises a non-aqueous solvent and an imid acid or imidate salt represented by the above general formula [1], wherein the content of the non-aqueous solvent having a relative permittivity (at 25°C) of 10 or less is 50 to 100% by volume. In the third non-aqueous battery according to the present disclosure, the non-aqueous electrolyte comprises a non-aqueous solvent and an imid acid or imidate salt represented by the above general formula [1], wherein the content of the non-aqueous solvent having a relative permittivity (at 25°C) of 10 or less is 50 to 100% by volume. In the retention method according to the second disclosure, the non-aqueous solution comprises a non-aqueous solvent and an imid acid or imidate salt represented by the above general formula [1], wherein the non-aqueous solvent has a dielectric constant of 10 or less (at 25°C) and the content of the non-aqueous solvent is 50 to 100% by volume. This configuration allows for the suppression of corrosion of austenitic stainless steel, even when in contact with it. The reason for this is not clear, but it is presumed to be as follows. As described above, in a non-aqueous solution or non-aqueous electrolyte, by setting the content of a solvent with a relative permittivity of 10 or less in the non-aqueous solvent to 50-100% by volume, the dissociation of the imide anion and metal cation in general formula [1] can be suppressed, and the corrosion reaction of austenitic stainless steel by imide anions can be suppressed.

[0033] The non-aqueous solutions relating to the first disclosure are described below.

[0034] [Non-aqueous solution] Non-aqueous solutions include non-aqueous solvents and imidic acids or imidates represented by general formula [1]. (Imido acids or imidates represented by general formula [1]) This document describes imid acids or imidates represented by the general formula [1] (hereinafter also referred to as "compounds represented by the general formula [1]"). X 1 , X 2 However, when each of these independently represents an alkoxy group having 1 to 10 carbon atoms as an organic group, the alkoxy group having 1 to 10 carbon atoms is not particularly limited, and may be linear or branched. As for the linear alkoxy group, an alkoxy group having 1 to 6 carbon atoms is preferred, and an alkoxy group having 1 to 3 carbon atoms is more preferred. As for the branched alkoxy group, an alkoxy group having 3 to 10 carbon atoms is preferred, and an alkoxy group having 3 to 6 carbon atoms is more preferred.

[0035] X 1 , X 2 However, when each independently represents an organic group having 2 to 10 carbon atoms, the alkenyloxy group having 2 to 10 carbon atoms is not particularly limited, but may be linear or branched, with alkenyloxy groups having 2 to 6 carbon atoms being preferred, and alkenyloxy groups having 2 to 3 carbon atoms being more preferred.

[0036] X 1 , X 2 However, when each represents an alkynyloxy group having 2 to 10 carbon atoms as an organic group, the alkynyloxy group having 2 to 10 carbon atoms is not particularly limited, but may be linear or branched, with alkynyloxy groups having 2 to 6 carbon atoms being preferred, and alkynyloxy groups having 2 to 3 carbon atoms being more preferred. Specific examples include, for example, propargyloxy groups.

[0037] X 1 , X 2However, when each independently represents a cycloalkoxy group having 3 to 10 carbon atoms as an organic group, the cycloalkoxy group having 3 to 10 carbon atoms is not particularly limited, but may be monocyclic or polycyclic, with a cycloalkoxy group having 3 to 8 carbon atoms being preferred, and a cycloalkoxy group having 3 to 6 carbon atoms being more preferred.

[0038] X 1 , X 2 However, when each independently represents a cycloalkenyloxy group having 3 to 10 carbon atoms as an organic group, the cycloalkenyloxy group having 3 to 10 carbon atoms is not particularly limited, but may be monocyclic or polycyclic, with a cycloalkenyloxy group having 3 to 8 carbon atoms being preferred, and a cycloalkenyloxy group having 3 to 6 carbon atoms being more preferred.

[0039] X 1 , X 2 However, when each group independently represents an aryloxy group with 6 to 10 carbon atoms as an organic group, the aryloxy group with 6 to 10 carbon atoms is not particularly limited, but can be monocyclic or polycyclic, and examples include phenyloxy group and naphthyloxy group.

[0040] X 1 , X 2 However, when each independently represents an organic group selected from the above group, the organic group may contain at least one of the following: a fluorine atom, an oxygen atom, or an unsaturated bond. Furthermore, "when a fluorine atom is present in the organic group" specifically refers to cases where a hydrogen atom in the above-mentioned group is replaced by a fluorine atom. Furthermore, "cases where an oxygen atom is present in the organic group" specifically refers to groups in which an "-O-" (ether bond) is interposed between the carbon atoms of the above-mentioned group.

[0041] X 1 , X 2 Preferably, the atom is a chlorine atom, a fluorine atom, or an alkynyloxy group having 2 to 10 carbon atoms.

[0042] Z represents -P(=O)<, -S(=O)²-, or -C(=O)-. a is either 0 or 1. When Z represents -P(=O)<, a is 1; when Z represents -S(=O)²- or -C(=O)-, a is 0. When Z represents -P(=O)<, Z is a trivalent linking group, and when Z represents -S(=O)2- or -C(=O)-, Z is a divalent linking group. Z preferably represents -P(=O)< or -S(=O)²-.

[0043] R 1 , R 2 However, when each of these independently represents an alkyl group having 1 to 10 carbon atoms as an organic group, the alkyl group having 1 to 10 carbon atoms is not particularly limited, and may be linear or branched. As for the linear alkyl group, alkyl groups having 1 to 6 carbon atoms are preferred, and alkyl groups having 1 to 3 carbon atoms are more preferred. As for the branched alkyl group, alkyl groups having 3 to 10 carbon atoms are preferred, and alkyl groups having 3 to 6 carbon atoms are more preferred.

[0044] R 1 , R 2 However, when each independently represents an alkenyl group having 2 to 10 carbon atoms as an organic group, the alkenyl group having 2 to 10 carbon atoms is not particularly limited, but may be linear or branched, with alkenyl groups having 2 to 6 carbon atoms being preferred, and alkenyl groups having 2 to 3 carbon atoms being more preferred.

[0045] R 1 , R 2 However, when each independently represents an alkynyl group having 2 to 10 carbon atoms as an organic group, the alkynyl group having 2 to 10 carbon atoms is not particularly limited, but may be linear or branched, with an alkynyl group having 2 to 6 carbon atoms being preferred, and an alkynyl group having 2 to 3 carbon atoms being more preferred.

[0046] R 1 , R 2However, when each group independently represents a cycloalkyl group having 3 to 10 carbon atoms as an organic group, the cycloalkyl group having 3 to 10 carbon atoms is not particularly limited, but may be monocyclic or polycyclic, with 3 to 8 carbon atoms being preferred, and 3 to 6 carbon atoms being more preferred.

[0047] R 1 , R 2 However, when each independently represents a cycloalkenyl group having 3 to 10 carbon atoms as an organic group, the cycloalkenyl group having 3 to 10 carbon atoms is not particularly limited, but may be monocyclic or polycyclic, with a cycloalkenyl group having 3 to 8 carbon atoms being preferred, and a cycloalkenyl group having 3 to 6 carbon atoms being more preferred.

[0048] R 1 , R 2 However, when each of these independently represents an aryl group having 6 to 10 carbon atoms as an organic group, the aryl group having 6 to 10 carbon atoms is not particularly limited, but can be monocyclic or polycyclic, and examples include phenyl groups and naphthyl groups.

[0049] R 1 , R 2 However, when each independently represents an alkoxy group with 1 to 10 carbon atoms as an organic group, the above X represents an alkoxy group with 1 to 10 carbon atoms. 1 , X 2 However, each of these can independently be described as being the same as the alkoxy groups having 1 to 10 carbon atoms when representing an alkoxy group having 1 to 10 carbon atoms as an organic group, and the preferred range is also the same.

[0050] R 1 , R 2 However, when each independently represents an alkenyloxy group with 2 to 10 carbon atoms as an organic group, the above X represents an alkenyloxy group with 2 to 10 carbon atoms. 1 , X 2 However, each can independently represent an alkenyloxy group having 2 to 10 carbon atoms as an organic group, and the same can be listed as an alkenyloxy group having 2 to 10 carbon atoms, and the preferred range is also the same.

[0051] R 1 , R 2 However, when each independently represents an alkynyloxy group with 2 to 10 carbon atoms as an organic group, the above X represents an alkynyloxy group with 2 to 10 carbon atoms. 1 , X 2 However, independently of each other, we can list the same alkynyloxy groups with 2 to 10 carbon atoms as the organic group, and the preferred range is also the same.

[0052] R 1 , R 2 However, when each independently represents a cycloalkoxy group with 3 to 10 carbon atoms as an organic group, the above X represents a cycloalkoxy group with 3 to 10 carbon atoms. 1 , X 2 However, independently of each other, we can list the same cycloalkoxy groups with 3 to 10 carbon atoms as those representing organic groups, and the preferred range is also the same.

[0053] R 1 , R 2 However, when each independently represents a cycloalkenyloxy group with 3 to 10 carbon atoms as an organic group, the above X is an example of a cycloalkenyloxy group with 3 to 10 carbon atoms. 1 , X 2 However, independently of each other, examples can be given that are the same as cycloalkenyloxy groups having 3 to 10 carbon atoms when representing an organic group, and the preferred range is also the same.

[0054] R 1 , R 2 However, when each independently represents an aryloxy group with 6 to 10 carbon atoms as an organic group, the above X represents an aryloxy group with 6 to 10 carbon atoms. 1 , X 2However, independently of each other, examples can be given that are the same as those of aryloxy groups having 6 to 10 carbon atoms when representing an aryloxy group having 6 to 10 carbon atoms as an organic group, and the preferred range is also the same.

[0055] R 1 , R 2 However, when each independently represents an organic group selected from the above group, the organic group may contain at least one of the following: a fluorine atom, an oxygen atom, or an unsaturated bond. Furthermore, "when a fluorine atom is present in the organic group" specifically refers to cases where a hydrogen atom in the above-mentioned group is replaced by a fluorine atom. Furthermore, "cases where an oxygen atom is present in the organic group" specifically refers to groups in which an "-O-" (ether bond) is interposed between the carbon atoms of the above-mentioned group. R 1 , R 2 However, when each independently represents an organic group selected from the above group, the organic group may have further substituents.

[0056] R 1 Preferably, the element is a chlorine atom, a fluorine atom, or a fluorine-substituted alkyl group having 1 to 10 carbon atoms. R 2 Preferably, the element is a chlorine atom, a fluorine atom, or a fluorine-substituted alkyl group having 1 to 10 carbon atoms.

[0057] M m+ represents a proton, alkali metal cation, alkaline earth metal cation, or onium cation, and m represents the valency of the cation. M m+ The alkali metal cations that represent alkali metal cations are not particularly limited, but examples include lithium ions, sodium ions, or potassium ions. M m+ When represents an alkaline earth metal cation, the alkaline earth metal cation is not particularly limited, but examples include magnesium ions or calcium ions. Mm+ When represents an onium cation, the onium cation is not particularly limited, but examples include trialkylammonium ions, tetraalkylammonium ions, tetraalkylphosphonium ions, imidazolium ions, and ammonium ions having a spiro skeleton.

[0058] Examples of trialkylammonium ions include ions in which three alkyl groups and one proton are bonded to a nitrogen atom. The number of carbon atoms in the alkyl group of the trialkylammonium ion is preferably 1 to 6. The three alkyl groups in the trialkylammonium ion may be the same or different from each other. The number of carbon atoms in the alkyl group of the tetraalkylammonium ion is preferably 1 to 6, and the number of carbon atoms in the alkyl group of the tetraalkylphosphonium ion is preferably 1 to 6. The four alkyl groups in the tetraalkylammonium ion may be the same or different from each other, and the four alkyl groups in the tetraalkylphosphonium ion may be the same or different from each other. The ammonium ion having a spiro skeleton is preferably, for example, 5-azoniaspiron[4.4]nonane.

[0059] M m+ Preferably, represents an alkali metal cation or a trialkylammonium ion.

[0060] The anionic parts of compounds represented by general formula [1] are shown below, but the disclosure is not limited to these. Me represents a methyl group and Et represents an ethyl group.

[0061] [ka]

[0062] Compounds represented by general formula [1] can be synthesized by known methods. In a preferred embodiment, compounds represented by general formula [1] can be synthesized by the method described in the examples below.

[0063] The compounds represented by the general formula [1] may be used individually, or two or more compounds may be mixed in any combination and ratio according to the application. The concentration of the compound represented by the general formula [1] in the non-aqueous solution is not particularly limited, but is preferably 1 to 90% by mass, more preferably 1 to 80% by mass, and even more preferably 1 to 70% by mass.

[0064] (Non-aqueous solvent) The type of non-aqueous solvent used in the non-aqueous solution of this disclosure is not particularly limited, and any non-aqueous solvent can be used. The non-aqueous solvent is preferably at least one selected from the group consisting of cyclic esters, linear esters, cyclic ethers, linear ethers, sulfone compounds, sulfoxide compounds, and ionic liquids. Specifically, ethyl methyl carbonate (hereinafter also referred to as "EMC"), dimethyl carbonate (hereinafter also referred to as "DMC"), diethyl carbonate (hereinafter also referred to as "DEC"), methyl propyl carbonate, ethyl propyl carbonate, methyl butyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, 2,2,2-trifluoroethyl ethyl carbonate, 2,2,2-trifluoroethyl Tylpropyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, 1,1,1,3,3,3-hexafluoro-1-propylmethyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propylethyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propylpropyl carbonate, bis(1,1,1,3,3,3-hexafluoro-1-propyl) carbonate, ethylene carbonate Preferably, it is at least one selected from the group consisting of ethyl acetate (hereinafter also referred to as "EC"), propylene carbonate (hereinafter also referred to as "PC"), butylene carbonate, fluoroethylene carbonate (hereinafter also referred to as "FEC"), difluoroethylene carbonate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl 2-fluoropropionate, ethyl 2-fluoropropionate, diethyl ether, dibutyl ether, diisopropyl ether, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, furan, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, N,N-dimethylformamide, acetonitrile, propionitrile, dimethyl sulfoxide, sulfolane, γ-butyrolactone, and γ-valerolactone. Furthermore, in this disclosure, an ionic liquid that adopts a salt structure may be used as the non-aqueous solvent.

[0065] The non-aqueous solvent being at least one selected from the group consisting of cyclic esters and linear esters is preferable from the viewpoint of battery characteristics, as it provides excellent input / output characteristics at low temperatures. Furthermore, the non-aqueous solvent is preferably at least one selected from the group consisting of cyclic carbonates and linear carbonates, as this provides excellent high-temperature cycle characteristics from the viewpoint of battery properties.

[0066] The non-aqueous solvent preferably contains a cyclic ester, and the cyclic ester is preferably a cyclic carbonate. Specific examples of the above-mentioned cyclic carbonates include EC, PC, butylene carbonate, and FEC, and it is preferable that at least one is selected from the group consisting of EC, PC, and FEC.

[0067] It is also preferable that the non-aqueous solvent contains a linear ester, and that the linear ester is a linear carbonate. Specific examples of the above-mentioned linear carbonates include EMC, DMC, DEC, methylpropyl carbonate, ethylpropyl carbonate, 2,2,2-trifluoroethylmethyl carbonate, 2,2,2-trifluoroethylethyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propylmethyl carbonate, and 1,1,1,3,3,3-hexafluoro-1-propylethyl carbonate, among others, and it is preferable that at least one is selected from the group consisting of EMC, DMC, DEC, and methylpropyl carbonate.

[0068] Furthermore, specific examples of the above esters include methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl 2-fluoropropionate, and ethyl 2-fluoropropionate.

[0069] The non-aqueous solvent content is 50-100% by volume, and the relative permittivity (at 25°C) of the non-aqueous solvent is 10 or less.

[0070] The dielectric constant of non-aqueous solvents (at 25°C) is described in detail below. <Non-aqueous solvents with a relative permittivity of 10 or less at 25°C> The number in parentheses after the name represents the relative permittivity. EMC(3), DMC(3), DEC(3), methyl acetate(7), ethyl acetate(6), ethyl propionate(6) diethyl ether(4), 1,2-dimethoxyethane(7), tetrahydrofuran(8), 2-methyltetrahydrofuran(7), 1,3-dioxolane(7), 1,4-dioxane(2) The above information is quoted from the Battery Technology Committee of the Electrochemical Society of Japan, "Battery Handbook, p. 534, published in 2010." Ethyl propionate (6°C, 19°C) This information is quoted from "Electrostatic Safety Guidelines (1988), Ministry of Labor, Industrial Safety Research Institute, Document No. 3, Conductivity of Various Liquids." The relative permittivity of ethyl propionate shall be the relative permittivity at 19°C. Diisopropyl ether (4°C, 25°C), tetrahydropyran (6°C, 25°C) The above is quoted from "Engineer Book Technical Data Collection 19th Edition p324" by Hyoshin Equipment Co., Ltd.

[0071] Furthermore, based on the relative permittivity values ​​of the above solvents at 25°C, it can be estimated that the relative permittivity of the following solvents at 25°C is also 10 or less. Methylpropyl carbonate, ethylpropyl carbonate, methylbutyl carbonate, 2,2,2-trifluoroethylmethyl carbonate, 2,2,2-trifluoroethylethyl carbonate, 2,2,2-trifluoroethylpropyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, 1,1,1,3,3,3-hexafluoro-1-propylmethyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propylethyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propylpropyl carbonate, bis(1,1,1,3,3,3-hexafluoro-1-propyl) carbonate, methyl propionate, methyl 2-fluoropropionate, ethyl 2-fluoropropionate, dibutyl ether, diethylene glycol dimethyl ether, furan

[0072] <Non-aqueous solvents with a relative permittivity greater than 10 at 25°C> The number in parentheses after the name represents the relative permittivity. EC (90, 40℃), PC (65), butylene carbonate (56), sulfolane (43, 30℃), γ-butyrolactone (39), acetonitrile (38) The above information is quoted from the Battery Technology Committee of the Electrochemical Society of Japan, "Battery Handbook, p. 534, published in 2010." The dielectric constants of EC and sulfolane are to be those at 40°C and 30°C, respectively. N,N-dimethylformamide (37°C, 25°C), propionitrile (29°C, 20°C), dimethyl sulfoxide (47°C, 25°C) The above information is quoted from "Engineer Book Technical Data Collection 19th Edition p324" by Hyoshin Equipment Co., Ltd. The dielectric constant of propionitrile is to be used at 20°C. Furthermore, based on the dielectric constant values ​​of the above solvents at 25°C, it can be estimated that the dielectric constants of the following solvents at 25°C are all greater than 10. Fluoroethylene carbonate (hereinafter also referred to as "FEC"), difluoroethylene carbonate, γ-valerolactone

[0073] The non-aqueous solvent content in the non-aqueous solvent is 50-100% by volume, and non-aqueous solutions containing such non-aqueous solvents and compounds represented by general formula [1] can help suppress corrosion even when in contact with austenitic stainless steel.

[0074] The non-aqueous solvent having a relative permittivity of 10 or less (at 25°C) is preferably at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, methyl acetate, ethyl acetate, ethyl propionate, 1,2-dimethoxyethane, and diethylene glycol dimethyl ether.

[0075] The content of the non-aqueous solvent having a relative permittivity (at 25°C) of 10 or less in the non-aqueous solvent is 50 to 100% by volume, preferably 55 to 100% by volume, and more preferably 70 to 100% by volume. Non-aqueous solvents may be used individually or in combination of two or more.

[0076] Insofar as it does not impair the essence of this disclosure, commonly used additives may be added to the non-aqueous solutions of this disclosure in any proportion. Examples of additives include those commonly used in the non-aqueous electrolytes of this disclosure, as described later.

[0077] The non-aqueous solution is in contact with the austenitic stainless steel. The mode of contact is not particularly limited. Examples of austenitic stainless steel include, but are not limited to, containers, piping, and wetted components (such as current collectors and cans) that contain austenitic stainless steel. Furthermore, from the viewpoint of corrosion resistance, the martensite content in the austenitic stainless steel of this disclosure is preferably as low as possible. Specifically, it is preferably 80 volume% or less, more preferably 50 volume% or less, even more preferably 20 volume% or less, even more preferably 10 volume% or less, and particularly preferably 5 volume% or less. Ideally, it is desirable for it to be substantially zero. The martensite content (volume fraction) can be calculated using the saturation magnetization and initial magnetic susceptibility. The above volume fraction can be calculated by referring to S. Kobayahi, A. Saito, S. Takahashi, Y. Kamada and H. Kikuchi: Appl. Phys. Lett. 92(2008) 182508, 1-3. In addition, the above content can also be calculated from the results of X-ray diffraction measurements.

[0078] The container is preferably one whose storage section is made of austenitic stainless steel. The above austenitic stainless steel may be treated by using at least one of the following methods: acid cleaning and electropolishing. Acid cleaning is a method of oxidizing the surface of stainless steel by immersing it in a strong oxidizing agent such as nitric acid. Electropolishing is a method of electropolishing the surface of stainless steel by using stainless steel as the anode (positive side) and passing a direct current through an electrolyte between it and the cathode (negative side).

[0079] The container may have a housing made of austenitic stainless steel, and for example, an outer periphery made of another material may be formed on the outside of the housing (the side opposite to the surface in contact with the non-aqueous electrolyte). There are no particular limitations on the material used to form the outer periphery, but examples include polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, and polyamide resins such as nylon.

[0080] Furthermore, the container may or may not have a lid, but it is preferable to have a lid in order to improve airtightness and prevent deterioration of the non-aqueous electrolyte due to contact with oxygen in the air during storage. There are no particular limitations on the material of the lid, but it is preferable that it be made of austenitic stainless steel.

[0081] The shape of the container is not particularly limited and can be any shape, such as a bottle or a cylindrical shape. Bottle-type containers can have any shape in their horizontal cross-section, such as a circle or a polygon with three to eight sides. Of these, a circular horizontal cross-section is preferable from the viewpoint of container strength and processability. It is also possible to continuously change the cross-sectional area in the vertical direction of the container. For example, by making the cross-sectional area near the center in the height direction smaller than that near both ends, a constricted structure can be formed in which a part of the container body is narrowed, or the surface of the container can be made uneven to make it easier to grip.

[0082] The container capacity is not particularly limited, but from the standpoint of ease of handling, 10 to 1,500,000 cm³ is recommended. 3 Preferably, 20-250,000 cm 3 More preferably, 50-20,000 cm 3 More preferably, 100-1,000 cm 3The above is particularly preferable. The diameter of the container body is not particularly limited, but from the viewpoint of handling, 50 to 1,500 mm is preferred, and 60 to 1,200 mm is more preferred.

[0083] Preferred austenitic stainless steels include SUS304, SUS316, and SUS316L. SUS304, SUS316, and SUS316L are specified in the Japanese Industrial Standard JIS G 4305. These austenitic stainless steels are preferably pre-treated by acid cleaning or electropolishing.

[0084] In the first to third disclosures, corrosion of austenitic stainless steel can be suppressed even when a non-aqueous solution or non-aqueous electrolyte is brought into contact with the austenitic stainless steel. Corrosion suppression can be measured by quantitatively determining the content of metal components (iron atoms (Fe atoms)) dissolved in the non-aqueous solution or non-aqueous electrolyte before and after contacting and holding a non-aqueous solution or non-aqueous electrolyte with austenitic stainless steel. After being held at 45°C for 6 months, and before being held, the content of metal components (iron atoms) dissolved in the non-aqueous solution or non-aqueous electrolyte is preferably 5 ppm by mass or less, and more preferably 4 ppm by mass or less. The Fe content in the solution before and after holding was measured using an ICP emission spectrometer (Agilent 5110 ICP-OES).

[0085] Furthermore, this disclosure relates to a method for retaining a non-aqueous solution in a wetted member, including an austenitic stainless steel, The aforementioned non-aqueous solution comprises a non-aqueous solvent and an imid acid or imidate salt represented by the following general formula [1], The present invention relates to a retention method wherein the non-aqueous solvent having a relative permittivity of 10 or less (at 25°C) contains 50 to 100% by volume.

[0086] [ka]

[0087] [In general formula [1], X 1 , X 2 each independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and at least one selected from fluorine atoms, oxygen atoms, nitrogen atoms, and unsaturated bonds may be present in the organic group. Z represents -P(=O)<, -S(=O)2-, or -C(=O)-. a is 0 or 1. When Z represents -P(=O)<, a is 1, and when Z represents -S(=O)2- or -C(=O)-, a is 0. R 1 , R 2 each independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and at least one selected from fluorine atoms, oxygen atoms, and unsaturated bonds may be present in the organic group. M m+ represents a proton, an alkali metal cation, an alkaline earth metal cation, or an onium cation, and m represents the valence of the cation.]

[0088] The wetted part member containing austenitic stainless steel is as described above. The imidic acid or imidic acid salt represented by general formula [1] is as described above. Non-aqueous solvents, and non-aqueous solvents with a dielectric constant of 10 or less (at 25°C), are as described above. The content of the non-aqueous solvent having a relative permittivity (at 25°C) of 10 or less in the non-aqueous solvent is 50 to 100% by volume, preferably 60 to 100% by volume, and more preferably 80 to 100% by volume. The concentration of the compound represented by the general formula [1] in the non-aqueous solution is not particularly limited, but is preferably 1 to 90% by mass, more preferably 1 to 80% by mass, and even more preferably 1 to 70% by mass. Furthermore, in the "method for retaining non-aqueous solutions in wetted components including austenitic stainless steel," "retention" includes the transfer of non-aqueous solutions in piping, the retention of non-aqueous solutions in piping, and the storage of non-aqueous solutions in containers, etc.

[0089] Insofar as it does not impair the essence of this disclosure, commonly used additives may be added to the non-aqueous solutions of this disclosure in any proportion. Examples of additives include those commonly used in the non-aqueous electrolytes of this disclosure, as described later.

[0090] The temperature in the above holding method is not particularly limited, but -20°C to 50°C is preferred. The pressure in the above holding method is not particularly limited, but 0 to 0.25 MPaG is preferred. The above holding method can be carried out in the gas phase. Nitrogen gas is preferred as the gas phase. Dry air filling is also preferred in the gas phase. The amount of moisture in the gas phase is not particularly limited, but 5 to 150 ppm by mass is preferred.

[0091] Furthermore, this disclosure relates to a non-aqueous battery comprising a wetted member including austenitic stainless steel, and a non-aqueous electrolyte in contact with said wetted member, The non-aqueous electrolyte comprises a non-aqueous solvent and an imid acid or imidate salt represented by the following general formula [1], This invention relates to a non-aqueous battery in which the non-aqueous solvent having a relative permittivity (at 25°C) of 10 or less is present in a volume of 50 to 100%.

[0092] [Chemical formula]

[0093] [In general formula [1], X 1 and X 2 each independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and at least one selected from fluorine atoms, oxygen atoms, nitrogen atoms, and unsaturated bonds may be present in the organic group. Z represents -P(=O)<, -S(=O)2-, or -C(=O)-. a is 0 or 1. When Z represents -P(=O)<, a is 1, and when Z represents -S(=O)2- or -C(=O)-, a is 0. R 1 and R 2 each independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to M m+ represents a proton, an alkali metal cation, an alkaline earth metal cation, or an onium cation, and m represents the valence of the cation.]

[0094] The non-aqueous electrolyte is in contact with a liquid-contact member containing austenitic stainless steel. The mode of contact is not particularly limited. The wetted components, including austenitic stainless steel, are as described above. The imido acids or imido salts represented by the general formula [1] are as described above. Non-aqueous solvents, and non-aqueous solvents with a dielectric constant of 10 or less (at 25°C), are as described above. The content of the non-aqueous solvent having a relative permittivity (at 25°C) of 10 or less in the non-aqueous solvent is 50 to 100% by volume, preferably 60 to 100% by volume, and more preferably 80 to 100% by volume. The concentration of the compound represented by the general formula [1] in the non-aqueous electrolyte is not particularly limited, but is preferably 0.1 to 10% by mass, more preferably 0.5 to 8% by mass, and even more preferably 1 to 5% by mass.

[0095] Insofar as it does not impair the essence of this disclosure, commonly used additives may be further added to the non-aqueous electrolyte of this disclosure in any proportion.

[0096] (Regarding solutes) The non-aqueous electrolyte of this disclosure preferably contains a solute. The solute is not particularly limited, but it is preferably an ionic salt, and more preferably an ionic salt containing fluorine.

[0097] The solute is preferably an ionic salt consisting of a pair of at least one cation selected from the group consisting of alkali metal ions such as lithium ions and sodium ions, alkaline earth metal ions, and quaternary ammonium, and at least one anion selected from the group consisting of hexafluorophosphate anion, tetrafluoroborate anion, perchlorate anion, hexafluoroarsenate anion, hexafluoroantimonate anion, trifluoromethanesulfonate anion, bis(trifluoromethanesulfonyl)imide anion, bis(pentafluoroethanesulfonyl)imide anion, (trifluoromethanesulfonyl)(pentafluoroethanesulfonyl)imide anion, bis(fluorosulfonyl)imide anion, (trifluoromethanesulfonyl)(fluorosulfonyl)imide anion, (pentafluoroethanesulfonyl)(fluorosulfonyl)imide anion, and tris(trifluoromethanesulfonyl)methide anion.

[0098] The solute is a hexafluorophosphate (preferably LiPF). 6、 NaPF6), tetrafluoroborate (preferably LiBF 4、 Examples include NaBF4), bis(fluorosulfonyl)imide salts (preferably LiN(SO2F)2, NaN(SO2F)2), difluorophosphates (preferably LiPO2F2, NaPO2F2), fluorosulfonates (preferably LiFSO3, NaFSO3), bis(oxalato)borate salts (preferably LiB(C2O4)2, NaB(C2O4)2), difluoro(oxalato)borate salts (preferably LiBF2(C2O4), NaBF2(C2O4)), difluorobis(oxalato)phosphate salts (preferably LiPF2(C2O4)2, NaPF2(C2O4)2), or tetrafluoro(oxalato)phosphate salts (preferably LiPF4(C2O4), NaPF4(C2O4)).

[0099] The solutes are LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiFSO3, LiCF3SO3, LiC4F9SO3, LiN(SO2F)2, LiB(C2O4)2, LiBF2(C2O4), and LiPF2(C2O4). 2、 At least one selected from the group consisting of LiPF4(C2O4)LiAlO2, LiAlCl4, LiCl, and LiI, or NaPF6, NaBF4, NaSbF6, NaAsF6, NaClO4, NaFSO 3、 NaCF3SO3, NaC4F9SO3, NaN(SO2F) 2、 NaB(C2O4)2, NaBF2(C2O4), NaPF2(C2O4) 2、 It is preferable that the material be at least one selected from the group consisting of NaPF4(C2O4), NaAlO2, NaAlCl4, NaCl, and NaI.

[0100] These solutes may be used individually, or two or more may be mixed in any combination and ratio according to the application. In particular, considering the energy density, output characteristics, and lifespan of the non-aqueous electrolyte battery, it is preferable that the cation be at least one selected from the group consisting of lithium, sodium, potassium, magnesium, and quaternary ammonium, and the anion be at least one selected from the group consisting of hexafluorophosphate anion, tetrafluoroborate anion, bis(trifluoromethanesulfonyl)imide anion, and bis(fluorosulfonyl)imide anion.

[0101] The total amount of solute in the non-aqueous electrolyte of this disclosure (hereinafter also referred to as "solute concentration") is not particularly limited, but the lower limit is preferably 0.5 mol / L or more, more preferably 0.7 mol / L or more, and even more preferably 0.9 mol / L or more. The upper limit of the solute concentration is preferably 5.0 mol / L or less, more preferably 4.0 mol / L or less, and even more preferably 2.0 mol / L or less. Setting the solute concentration to 0.5 mol / L or more can suppress the decrease in cycle characteristics and output characteristics of the non-aqueous electrolyte battery due to a decrease in ionic conductivity, and setting it to 5.0 mol / L or less can suppress the decrease in ionic conductivity and the decrease in cycle characteristics and output characteristics of the non-aqueous electrolyte battery due to an increase in the viscosity of the non-aqueous electrolyte.

[0102] (Regarding other additives) Other specific examples of additives include cyclohexylbenzene, cyclohexylfluorobenzene, fluorobenzene, biphenyl, difluoroanisole, tert-butylbenzene, tert-amylbenzene, 2-fluorotoluene, 2-fluorobiphenyl, vinylene carbonate, dimethylvinylene carbonate, vinylethylene carbonate, fluoroethylene carbonate, trans-difluoroethylene carbonate, methylpropargyl carbonate, ethylpropargyl carbonate, dipropargyl carbonate, and maleic anhydride. Succinic anhydride, propanesultone, 1,3-propanesultone, 1,3-propensultone, butanesultone, 1,3,2-dioxathiolan-2,2-dioxide, 4-propyl-1,3,2-dioxathiolan-2,2-dioxide, methylene methanedisulfate, ethylene methanedisulfate, trimethylene methanedisulfate, methyl methanesulfonate, 1,2-ethanedisulfonic anhydride, 1,6-diisocyanatohexane, tris(trimethylsilyl)borate, succinonitrile, (ethoxy)pentafluorocyclotriphosphatidyl Examples of compounds that have overcharge prevention effects, negative electrode film formation effects, and positive electrode protection effects include: Zen, lithium difluorobis(oxalato)phosphate, sodium difluorobis(oxalato)phosphate, potassium difluorobis(oxalato)phosphate, lithium difluorooxalatoborate, sodium difluorooxalatoborate, potassium difluorooxalatoborate, lithium bis(oxalato)borate, sodium bis(oxalato)borate, potassium bis(oxalato)borate, lithium tetrafluorooxalatophosphate, sodium tetrafluorooxalatophosphate, potassium tetrafluorooxalatophosphate, lithium tris(oxalato)phosphate, sodium tris(oxalato)phosphate, potassium tris(oxalato)phosphate, lithium difluorophosphate, sodium difluorophosphate, potassium difluorophosphate, lithium monofluorophosphate, sodium monofluorophosphate, potassium monofluorophosphate, lithium fluorosulfonate, sodium fluorosulfonate, potassium fluorosulfonate, methanesulfonyl fluoride, ethenesulfonyl fluoride, phenyl difluorophosphate, etc.

[0103] The non-aqueous electrolytes of this disclosure include vinylene carbonate, bis(oxalato)borate, difluorooxalatoborate, difluorobis(oxalato)phosphate, tetrafluorooxalatophosphate, difluorophosphate, fluorosulfonate, 1,3-propensultone, 1,3-propanesultone, 1,6-diisocyanatohexane, ethynylethylene carbonate, 1,3,2-dioxathiolan-2,2-dioxide, 4-propyl-1,3,2-dioxathiolan-2,2-dioxide, methylenemethanedisulfonate, and 1,2-ethane. The solution may contain at least one selected from disulfonic anhydride, methanesulfonyl fluoride, tris(trimethylsilyl)borate, (ethoxy)pentafluorocyclotriphosphazene, lithium tetrafluoro(malonato)phosphate, tetrafluoro(picolinato)phosphate, 1,3-dimethyl-1,3-divinyl-1,3-di(1,1,1,3,3,3-hexafluoroisopropyl)disiloxane, tetravinylsilane, t-butylbenzene, t-amylbenzene, fluorobenzene, and cyclohexylbenzene. The content of the above additives in the non-aqueous electrolyte is preferably 0.01% by mass or more and 5.0% by mass or less, based on the total amount of the non-aqueous electrolyte.

[0104] The content of the other additives in the non-aqueous electrolyte is preferably 0.01% by mass or more and 8.0% by mass or less, relative to the total amount of the non-aqueous electrolyte.

[0105] Furthermore, when the ionic salt listed as the solute is present in a non-aqueous electrolyte at a concentration lower than 0.5 mol / L, which is the lower limit of the solute's preferred concentration, it can act as an "other additive" and exhibit negative electrode film formation and positive electrode protection effects. In this case, the content in the non-aqueous electrolyte is preferably between 0.01% and 5.0% by mass. Examples of ionic salts in this case include, for example, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, and lithium (trifluoromethanesulfonyl)(fluorosulfonyl)imide when the non-aqueous electrolyte battery is a lithium-ion battery, and sodium hexafluorophosphate, sodium tetrafluoroborate, sodium trifluoromethanesulfonate, sodium bis(trifluoromethanesulfonyl)imide, sodium bis(fluorosulfonyl)imide, and sodium (trifluoromethanesulfonyl)(fluorosulfonyl)imide when the non-aqueous electrolyte battery is a sodium-ion battery.

[0106] Furthermore, alkali metal salts other than the solutes mentioned above may be used as additives. Specifically, examples include carboxylates such as lithium acrylate, sodium acrylate, lithium methacrylate, and sodium methacrylate, as well as sulfate esters such as lithium methyl sulfate, sodium methyl sulfate, lithium ethyl sulfate, and sodium ethyl sulfate.

[0107] In the non-aqueous electrolyte of this disclosure, from the viewpoint of improving the durability (lifespan) of the battery, if the non-aqueous electrolyte battery is a lithium-ion battery, it is preferable that at least one selected from vinylene carbonate, fluoroethylene carbonate, lithium bis(oxalato)borate, lithium difluorooxalatoborate, lithium difluorobis(oxalato)phosphate, lithium tetrafluorooxalatophosphate, lithium bis(fluorosulfonyl)imide, lithium difluorophosphate, lithium fluorosulfonate, 1,3-propensultone, 1,3-propanesultone, 1,3,2-dioxathiolane-2,2-dioxide, and 4-propyl-1,3,2-dioxathiolane-2,2-dioxide is contained in 0.01 to 5.0% by mass of the total amount of the non-aqueous electrolyte. In the case of a non-aqueous electrolyte battery, it is preferable that at least one selected from vinylene carbonate, fluoroethylene carbonate, sodium bis(oxalato)borate, sodium difluorooxalatoborate, sodium difluorobis(oxalato)phosphate, sodium tetrafluorooxalatophosphate, sodium bis(fluorosulfonyl)imide, sodium difluorophosphate, sodium fluorosulfonate, 1,3-propensultone, 1,3-propanesultone, 1,3,2-dioxathiolan-2,2-dioxide, and 4-propyl-1,3,2-dioxathiolan-2,2-dioxide be included in 0.01 to 5.0% by mass relative to the total amount of the non-aqueous electrolyte.

[0108] In the above-described non-aqueous battery, the non-aqueous electrolyte is in contact with a wetted component, which includes austenitic stainless steel. The manner of contact is not particularly limited. The wetted components, including austenitic stainless steel, are as described above. The wetted components, including austenitic stainless steel, used in the above-mentioned non-aqueous battery are not particularly limited, but examples include the current collector at the positive electrode and the current collector at the negative electrode, which will be described later.

[0109] The non-aqueous battery according to the embodiments of this disclosure preferably includes at least the non-aqueous electrolyte, a positive electrode, and a negative electrode. More specifically, the non-aqueous battery of this disclosure preferably comprises a positive electrode, a negative electrode made of lithium or a negative electrode material capable of intercalating and deintercalating lithium, the non-aqueous electrolyte, and a current collector, separator, container, etc. Alternatively, the non-aqueous battery of this disclosure preferably comprises a positive electrode, a negative electrode made of sodium or a negative electrode material capable of intercalating and deintercalating sodium, the non-aqueous electrolyte, and a current collector, separator, container, etc. Alternatively, the non-aqueous electrolyte battery of this disclosure preferably comprises a positive electrode, a negative electrode made of potassium or a negative electrode material capable of intercalating and deintercalating potassium, the non-aqueous electrolyte, and a current collector, separator, container, etc.

[0110] [Positive electrode] The positive electrode consists of a positive electrode active material, a current collector, a conductive material, and a binder. The type of positive electrode active material is not particularly limited, but a material that allows reversible insertion and removal of lithium ions, sodium ions, or potassium ions is used.

[0111] In the case of a lithium-ion secondary battery in which the cations in the non-aqueous electrolyte are mainly lithium, (a) the positive electrode active material constituting the positive electrode is not particularly limited as long as it is a variety of materials that can be charged and discharged, but examples include (A) a lithium transition metal composite oxide having a layered structure and containing at least one of the metals nickel, manganese, and cobalt, (B) a lithium manganese composite oxide having a spinel structure, (C) a lithium-containing olivine-type phosphate, and (D) a lithium-rich layered transition metal oxide having a layered rock salt-type structure.

[0112] ((A) Lithium transition metal composite oxide) Examples of lithium transition metal composite oxides having a layered structure and containing at least one metal (A) of nickel, manganese, and cobalt as positive electrode active material include lithium-cobalt composite oxide, lithium-nickel composite oxide, lithium-nickel-cobalt composite oxide, lithium-nickel-cobalt-aluminum composite oxide, lithium-cobalt-manganese composite oxide, lithium-nickel-manganese composite oxide, and lithium-nickel-manganese-cobalt composite oxide. Furthermore, some of the transition metal atoms that make up the main body of these lithium transition metal composite oxides may be substituted with other elements such as Al, Ti, V, Cr, Fe, Cu, Zn, Mg, Ga, Zr, Si, B, Ba, Y, and Sn. Specific examples of lithium-cobalt composite oxides and lithium-nickel composite oxides include LiCoO2, LiNiO2, and lithium cobalt oxide (LiCoO2) with added heterogeneous elements such as Mg, Zr, Al, and Ti. 0.98 Mg 0.01 Zr 0.01 O2, LiCo 0.98 Mg 0.01 Al 0.01 O2, LiCo 0.975 Mg 0.01 Zr0.005 Al 0.01 LiCoO2 particles may be used, such as lithium cobalt oxide with a rare earth compound fixed to its surface, as described in Japanese Patent Publication No. WO2014 / 034043. Alternatively, as described in Japanese Patent Publication No. 2002-151077, a LiCoO2 particle powder in which a portion of the particle surface is coated with aluminum oxide may be used. Lithium-nickel-cobalt composite oxides and lithium-nickel-cobalt-aluminum composite oxides are represented by general formula (1-1). Li a Ni 1-b-c Co b M 1 c O2(1-1)

[0113] In formula (1-1), M 1 a is at least one element selected from the group consisting of Al, Fe, Mg, Zr, Ti, and B, where a satisfies the conditions 0.9 ≤ a ≤ 1.2, and b and c satisfy the conditions 0.1 ≤ b ≤ 0.3 and 0 ≤ c ≤ 0.1. These can be prepared, for example, in accordance with the manufacturing methods described in Japanese Patent Publication No. 2009-137834, etc. Specifically, LiNi 0.8 Co 0.2 O2, LiLiLi 0.85 Co 0.10 Al 0.05 O2, LiLiLi 0.87 Co 0.10 Al 0.03 O2, LiLiLi 0.6 Co 0.3 Al 0.1 Examples include O2. Specific examples of lithium-cobalt-manganese composite oxides and lithium-nickel-manganese composite oxides include LiNi 0.5 Mn 0.5 O2, LiCo 0.5 Mn 0.5 Examples include O2. Examples of lithium-nickel-manganese-cobalt composite oxides include lithium-containing composite oxides represented by general formula (1-2). Li d Ni e Mnf Co g M 2 h O2(1-2)

[0114] In formula (1-2), M 2 is at least one element selected from the group consisting of Al, Fe, Mg, Zr, Ti, B, and Sn, d is 0.9 ≤ d ≤ 1.2, and e, f, g, and h satisfy the conditions e + f + g + h = 1, 0 ≤ e ≤ 0.7, 0 ≤ f ≤ 0.5, 0 ≤ g ≤ 0.5, and h ≥ 0. Lithium-nickel-manganese-cobalt composite oxides are preferably those containing manganese within the range shown in general formula (1-2) to enhance structural stability and improve safety at high temperatures in lithium secondary batteries, and are more preferably those further containing cobalt within the range shown in general formula (1-2) to enhance the high efficiency characteristics of lithium-ion secondary batteries. Specifically, for example, Li[Ni] has a charge / discharge range of 4.3V or higher. 1 / 3 Mn 1 / 3 Co 1 / 3 ]O2, Li[Ni 0.45 Mn 0.35 Co 0.2 ]O2, Li[Ni 0.5 Mn 0.3 Co 0.2 ]O2, Li[Ni 0.6 Mn 0.2 Co 0.2 ]O2, Li[Ni 0.49 Mn 0.3 Co 0.2 Zr 0.01 ]O2, Li[Ni 0.49 Mn 0.3 Co 0.2 Mg 0.01 Examples include O2.

[0115] ((B) Lithium manganese composite oxide having a spinel structure) Examples of lithium manganese composite oxides having a spinel structure as the positive electrode active material (B) include spinel-type lithium manganese composite oxides represented by general formula (1-3). Li j (Mn 2-k M3 k )O4(1 - 3) In formula (1 - 3), M 3 is at least one metal element selected from the group consisting of Ni, Co, Fe, Mg, Cr, Cu, Al, and Ti; j satisfies 1.05 ≤ j ≤ 1.15; and k satisfies 0 ≤ k ≤ 0.20. Specifically, for example, LiMn2O4, LiMn 1.95 Al 0.05 O4, LiMn 1.9 Al 0.1 O4, LiMn 1.9 Ni 0.1 O4, LiMn 1.5 Ni 0.5 O4, etc. may be mentioned.

[0116] ((C) Lithium - containing olivine - type phosphate) Examples of the positive electrode active material (C) lithium - containing olivine - type phosphate include those represented by the general formula (1 - 4). LiFe 1-n M 4 n PO4(1 - 4) In formula (1 - 4), M 4 is at least one selected from Co, Ni, Mn, Cu, Zn, Nb, Mg, Al, Ti, W, Zr, and Cd; and n satisfies 0 ≤ n ≤ 1. Specifically, for example, LiFePO4, LiCoPO4, LiNiPO4, LiMnPO4, etc. may be mentioned, and among them, LiFePO4 and / or LiMnPO4 are preferred.

[0117] ((D) Lithium - rich layered transition metal oxide) Examples of the positive electrode active material (D) lithium - rich layered transition metal oxide having a layered rock - salt - type structure include those represented by the general formula (1 - 5). xLiM 5 O2·(1 - x)Li2M 6 O3(1 - 5) In formula (1 - 5), x is a number satisfying 0 < x < 1; and M 5 has an average oxidation number of 3 +It is at least one metallic element, M 6 The average oxidation number is 4 + It is at least one metallic element. In formulas (1-5), M 5 This is preferably a single metallic element selected from trivalent Mn, Ni, Co, Fe, V, and Cr, but it may also be an equal amount of divalent and tetravalent metals with an average oxidation state of 3. Also, in equation (1-5), M 6 It is preferably one or more metallic elements selected from Mn, Zr, and Ti. Specifically, 0.5[LiNi 0.5 Mn 0.5 O2]·0.5[Li2MnO3], 0.5[LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2]·0.5[Li2MnO3], 0.5[LiNi 0.375 Co 0.25 Mn 0.375 O2]·0.5[Li2MnO3], 0.5[LiNi 0.375 Co 0.125 Fe 0.125 Mn 0.375 O2]·0.5[Li2MnO3], 0.45[LiNi 0.375 Co 0.25 Mn 0.375 Examples include [O2], 0.10[Li2TiO3], and 0.45[Li2MnO3]. The positive electrode active material (D) represented by this general formula (1-5) is known to exhibit high capacity when charged at high voltages of 4.4V (Li reference) or higher (for example, U.S. Patent No. 7,135,252).

[0118] These positive electrode active materials can be prepared in accordance with the manufacturing methods described in, for example, Japanese Patent Publication No. 2008-270201, WO2013 / 118661, Japanese Patent Publication No. 2013-030284, etc. The positive electrode active material may contain at least one selected from (A) to (D) above as its main component. Other materials that may be included include, for example, transition element chalcogenides such as FeS2, TiS2, V2O5, MoO3, and MoS2, or conductive polymers such as polyacetylene, poly(p-phenylene), polyaniline, and polypyrrole, activated carbon, radical-generating polymers, and carbon materials. These positive electrode active materials may be used individually or in combination of two or more types.

[0119] When the cation is sodium, the cathode material (cathode active material) is not particularly limited, but examples include NaCrO2 and NaFe. 0.5 Co 0.5 O2, NaFe 0.4 Mn 0.3 Ni 0.3 O2, NaNi 0.5 Ti 0.3 Mn 0.2 O2, NaNi 1 / 3 Ti 1 / 3 Mn 1 / 3 O2, NaNi 0.33 Ti 0.33 Mn 0.16 Mg 0.17 O2, Na 2 / 3 Ni 1 / 3 Ti 1 / 6 Mn 1 / 2 O2, Na 2 / 3 Ni 1 / 3 Mn 2 / 3 Sodium-containing transition metal composite oxides such as O2, mixtures of multiple transition metals such as Co, Mn, and Ni in these sodium-containing transition metal composite oxides, and cases in which some of the transition metals in these sodium-containing transition metal composite oxides are substituted with other metals, polyanionic compounds such as NaFePO4, NaVPO4F, Na3V2(PO4)3, and Na2Fe2(SO4)3, and composition formula Na a M b [Fe(CN)6] cThe following materials can be used as positive electrode active materials: sodium salts of Prussian blue analogs represented by (M = Cr, Mn, Fe, Co, Ni, Cu, or Zn, with 0 ≤ a ≤ 2, 0.5 ≤ b ≤ 1.5, 0.5 ≤ c ≤ 1.5), oxides such as TiO2, V2O5, and MoO3, sulfides such as TiS2 and FeS, or conductive polymers such as polyacetylene, poly(p-phenylene), polyaniline, and polypyrrole, activated carbon, radical-generating polymers, carbon materials, etc. These positive electrode active materials may be used individually or in combination of two or more types.

[0120] When the cation is potassium, the cathode material (cathode active material) is not particularly limited, but can be polyanionic compounds such as KFePO4, KVOPO4, KFeSO4F, KVPO4F, K3V2(PO4)3, or compounds with the composition formula K a M b [Fe(CN)6] c Potassium salts of Prussian blue analogs represented by (M = Cr, Mn, Fe, Co, Ni, Cu, or Zn, where 0 ≤ a ≤ 2, 0.5 ≤ b ≤ 1.5, 0.5 ≤ c ≤ 1.5), KCrO2, K 0.3 MnO2, K 0.7 Fe 0.5 Mn 0.5 O2, K 2 / 3 Ni 1 / 2 Mg 1 / 6 Te 1 / 3 Potassium-containing transition metal composite oxides such as O2, conductive polymers such as polyacetylene, polymethyl methacrylate, poly(p-phenylene), polyaniline, and polypyrrole, perylene anhydrous, activated carbon, radical-generating polymers, and carbon materials are used. These positive electrode active materials may be used individually or in combination of two or more types.

[0121] In the positive electrode, for example, a positive electrode active material layer is formed on at least one surface of the positive electrode current collector. The positive electrode active material layer is composed of, for example, the aforementioned positive electrode active material, a binder, and, if necessary, a conductive agent. Examples of binders include polytetrafluoroethylene, polyvinylidene fluoride, or styrene-butadiene rubber (SBR) resin. Examples of conductive agents include acetylene black, Ketjen black, carbon fiber, or carbon materials such as graphite (granular graphite or flake graphite), and it is preferable to use acetylene black or Ketjen black with low crystallinity. These binders and conductive agents may be used individually or in combination of two or more types.

[0122] [Negative electrode] The negative electrode consists of a negative electrode active material, a current collector, a conductive material, and a binder. The type of negative electrode active material is not particularly limited, but a material that allows reversible insertion and removal of lithium ions, sodium ions, or potassium ions is used.

[0123] In the case of a lithium-ion secondary battery in which the cations in the non-aqueous electrolyte are mainly lithium, (c) as the negative electrode active material constituting the negative electrode, it is possible to dop and dedop it with lithium ions, and examples include (E) carbon materials with a d value of 002 planes in X-ray diffraction of 0.340 nm or less, (F) carbon materials with a d value of 002 planes in X-ray diffraction of 0.340 nm or more, (G) oxides of one or more metals selected from Si, Sn, and Al, (H) one or more metals selected from Si, Sn, and Al or alloys containing these metals or alloys with lithium, and (I) materials containing at least one selected from lithium titanium oxide. These negative electrode active materials can be used individually or in combination of two or more.

[0124] ((E) Carbon materials with a d value of 0.340 nm or less at the lattice plane (002 plane) in X-ray diffraction) Examples of carbon materials for which the d value of the lattice plane (002 plane) in the X-ray diffraction of the negative electrode active material (E) is 0.340 nm or less include pyrolysis carbons, cokes (e.g., pitch coke, needle coke, petroleum coke, etc.), graphites, calcined organic polymer compounds (e.g., phenolic resin, furan resin, etc., calcined at an appropriate temperature), carbon fibers, activated carbon, etc., and these may also be graphitized. The carbon material has a (002) plane interplanar spacing (d002) of 0.340 nm or less as measured by X-ray diffraction, and among these, its true density is 1.70 g / cm³. 3 A highly crystalline carbon material having properties similar to graphite is preferred.

[0125] ((F) Carbon materials with a d-value of 0.340 nm or more at the lattice plane (002 plane) in X-ray diffraction) Carbon materials with a d-value of the lattice plane (002 plane) exceeding 0.340 nm in X-ray diffraction of the negative electrode active material (F) include amorphous carbon, which is a carbon material in which the layered order hardly changes even when heat-treated at high temperatures of 2000°C or higher. Examples include hard carbon, mesocarbon microbeads (MCMB) fired at temperatures below 1500°C, and mesopazyme carbon fiber (MCF). Carbotron® P manufactured by Kureha Corporation is a typical example.

[0126] ((G) Oxides of one or more metals selected from Si, Sn, and Al) The negative electrode active material (G) can be an oxide of one or more metals selected from Si, Sn, and Al, such as silicon oxide or tin oxide, which can be doped and dedoped with lithium ions. SiO2 has a structure in which ultrafine silicon particles are dispersed in SiO2. x These are some examples. When this material is used as a negative electrode active material, charging and discharging proceeds smoothly because the Si that reacts with Li is made of ultrafine particles, while SiO having the above structure x Because the particles themselves have a small surface area, they exhibit good paintability when used as a composition (paste) for forming the negative electrode active material layer, as well as good adhesion of the negative electrode mixture layer to the current collector. Note that SiO x Because the volume change associated with charging and discharging is large, SiO x By using the aforementioned negative electrode active material (E), graphite, in a specific ratio with the negative electrode active material, it is possible to achieve both high capacity and good charge-discharge cycle characteristics.

[0127] (One or more metals selected from (H)Si, Sn, and Al, or alloys containing these metals, or alloys of these metals or alloys with lithium) The negative electrode active material (H) may be one or more metals selected from Si, Sn, and Al, or alloys containing these metals, or alloys of these metals or alloys with lithium. Examples include metals such as silicon, tin, and aluminum, as well as silicon alloys, tin alloys, and aluminum alloys. Materials in which these metals or alloys are alloyed with lithium during charging and discharging can also be used. Specific examples of these preferred materials include, for example, elemental metals such as silicon (Si) and tin (Sn) (e.g., in powder form), metal alloys, compounds containing the metal, and alloys containing tin (Sn) and cobalt (Co) in the metal, as described in WO2004 / 100293 and JP 2008-016424. When these metals are used as electrodes, they are preferred because they can exhibit high charging capacity and relatively little volume expansion and contraction during charging and discharging. Furthermore, these metals are known to exhibit high charging capacity when used as the negative electrode of a lithium-ion secondary battery because they alloy with Li during charging, which is also a preferred feature. Furthermore, negative electrode active materials formed from submicron diameter silicon pillars, negative electrode active materials made of silicon fibers, etc., as described in publications such as WO2004 / 042851 and WO2007 / 083155, may also be used.

[0128] ((I) Lithium titanium oxide) Examples of the negative electrode active material (I) lithium titanium oxide include lithium titanate having a spinel structure and lithium titanate having a ramsdellite structure. Examples of lithium titanates having a spinel structure include Li4+α Ti5O 12 (α changes within the range of 0 ≤ α ≤ 3 due to the charge-discharge reaction) is one example. Furthermore, lithium titanate having a ramsdelite structure is, for example, Li 2+β Examples include Ti3O7 (where β changes within the range of 0 ≤ β ≤ 3 due to the charge-discharge reaction). These negative electrode active materials can be prepared in accordance with the manufacturing methods described in, for example, Japanese Patent Publication No. 2007-018883 and Japanese Patent Publication No. 2009-176752.

[0129] When the cation is sodium, the negative electrode active material is not particularly limited, but can be a material capable of intercalating and deintercalating sodium metal or sodium ions. For example, sodium metal, alloys of sodium metal with other metals such as tin, intermetallic compounds, various carbon materials including hard carbon, metal oxides such as titanium oxide, metal nitrides, elemental tin, tin compounds, activated carbon, conductive polymers, etc. In addition to these, elemental phosphorus such as red phosphorus and black phosphorus, phosphorus compounds such as Co-P, Cu-P, Sn-P, Ge-P, and Mo-P, elemental antimony, antimony compounds such as Sb / C and Bi-Sb, etc. These negative electrode active materials may be used individually or in combination of two or more types.

[0130] When the cation is potassium, the negative electrode active material is not particularly limited, but can be a material capable of intercalating and deintercalating potassium metal or potassium ions. For example, potassium metal, alloys of potassium metal with other metals such as tin and bismuth, intermetallic compounds, phosphorus (elemental) such as red phosphorus and black phosphorus, various carbon materials, and metal oxides such as titanium oxide can be used. Examples of the carbon materials mentioned above include easily graphitizable carbon, poorly graphitizable carbon (also called hard carbon) with a (002) plane interplanar spacing of 0.37 nm or more, and graphite with a (002) plane interplanar spacing of 0.37 nm or less. For the latter, artificial graphite and natural graphite can be used. These negative electrode active materials may be used individually or in combination of two or more types.

[0131] In the negative electrode, for example, a negative electrode active material layer is formed on at least one surface of the negative electrode current collector. The negative electrode active material layer is composed of, for example, the aforementioned negative electrode active material, a binder, and, if necessary, a conductive agent. Examples of binders include polytetrafluoroethylene, polyvinylidene fluoride, or styrene-butadiene rubber (SBR) resin. Examples of conductive agents include acetylene black, Ketjen black, carbon fiber, or carbon materials such as graphite (granular graphite or flake graphite). These binders and conductive agents may be used individually or in combination of two or more types.

[0132] [Current collector] Copper, aluminum, stainless steel, nickel, titanium, or alloys thereof can be used for the positive and negative electrode current collectors. An active material layer is formed on at least one surface of the current collector. In one preferred embodiment, the wetted component, which includes austenitic stainless steel, is either a positive electrode current collector or a negative electrode current collector.

[0133] [Separator] As separators to prevent contact between the positive and negative electrodes, nonwoven fabrics, porous sheets, or films made of polyolefins (e.g., polypropylene, polyethylene), paper, or glass fibers are used. These materials are preferably microporous so that the electrolyte can permeate and ions can easily pass through.

[0134] [Exterior] For the outer casing, for example, metal cans such as coin-shaped, cylindrical, or rectangular cans, or laminated outer casings can be used. Examples of metal can materials include nickel-plated steel sheets, stainless steel sheets, nickel-plated stainless steel sheets, aluminum or its alloys, nickel, titanium, etc. For the laminated outer casing, for example, aluminum laminate film, SUS laminate film, silica-coated laminate film made of polypropylene or polyethylene, etc. can be used. In one preferred embodiment, the wetted member, which includes austenitic stainless steel, is made of a metal can material. [Examples]

[0135] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to such examples.

[0136] [Synthesis example 1] [HN(C2H5)3] + [(F2PO)2N] - This synthesis example utilizes the reaction described in Example 6 of Patent Document 2. 210 g of acetonitrile and 210 g (2.08 mol) of triethylamine were charged into a 1 L autoclave, cooled to 5°C with ice water, and 155 g (1.56 mol) of phosphoryl fluoride was introduced. Subsequently, 10.4 g (0.61 mol) of anhydrous ammonia was introduced over 1 hour. The reactor was heated to room temperature (23°C) and stirred for 48 hours. The resulting reaction solution contained [bis(difluorophosphoryl)imide]triethylammonium salt, an imide salt containing a phosphoryl group, and triethylamine fluoride as a byproduct. The reaction mixture was concentrated and acetonitrile was removed. Ethyl acetate was then added to the residue to form an ethyl acetate solution, which was then washed twice with water to remove the by-product, triethylamine fluoride. Furthermore, the ethyl acetate was removed by distillation under reduced pressure to obtain [bis(difluorophosphoryl)imide]triethylammonium salt.

[0137] [Synthesis example 2] Li + [(F2PO)2N] - This synthesis example utilizes the reaction described in Non-Patent Document 1. 60 g of tetrahydrofuran and 6.0 g (36.0 mmol) of lithium hexamethyldisilazane were charged into a 150 mL autoclave, cooled to 5 °C with ice water, and 7.9 g (76.0 mmol) of phosphoryl fluoride was introduced over 2 hours. After the introduction, the mixture was stirred at 5 °C for 4 hours. The resulting reaction solution contained lithium [bis(difluorophosphoryl)imide] and trimethylsilyl fluoride as a by-product. By concentrating this reaction solution to remove trimethylsilyl fluoride, lithium [bis(difluorophosphoryl)imide] was obtained.

[0138] [Synthesis Example 3] K + [(CF3SO2)N(POCl2)] - This synthesis example utilizes the reaction described in Example 11 of Patent Document 3. 25 g of tetrahydrofuran as a reaction solvent and 2.6 g (10 mmol) of K[CF3SO2NSi(CH3)3] were charged into a 50 mL glass reactor equipped with a stirrer and a thermometer under a nitrogen atmosphere, and 1.53 g (10 mmol) of phosphorus oxychloride was added dropwise over 10 minutes. After the addition was complete, the liquid temperature was raised to 50 °C and stirring was continued for an additional 20 hours to conduct the reaction. The resulting reaction solution contained potassium [(trifluoromethanesulfonyl)(dichlorophosphoryl)imide] and trimethylsilyl chloride as a by-product. By concentrating this reaction solution to remove trimethylsilyl chloride, potassium [(trifluoromethanesulfonyl)(dichlorophosphoryl)imide] was obtained.

[0139] [Synthesis Example 4] Li + [(FSO2)N(POF2)] - The reaction was carried out in the same manner as in Synthesis Example 3, except that ethyl methyl carbonate (EMC) was used instead of tetrahydrofuran as the reaction solvent, Li[FSO2NSi(CH3)3] was used instead of K[CF3SO2NSi(CH3)3], and POF2Cl was used instead of phosphorus oxychloride. The resulting reaction solution contained lithium salt of [(fluorosulfonyl)(difluorophosphoryl)imide] and trimethylsilyl chloride as a by-product. By concentrating this reaction solution to remove trimethylsilyl chloride, an ethyl methyl carbonate solution of lithium salt of [(fluorosulfonyl)(difluorophosphoryl)imide] was obtained.

[0140] [Evaluation] This was carried out by immersing a test piece of SUS304 in the solutions in each of the following Examples and Comparative Examples and holding (preserving) it, and measuring the change in the iron atom content (Fe content) in the solution before and after preservation. The Fe content in the solution before and after holding was measured using an ICP emission spectroscopic analyzer (Agilent 5110 ICP-OES).

[0141] [Preparation of Test Piece] As the test piece, a test piece made of SUS304, which is an austenitic stainless steel (size: all 20 mm × 15 mm × 3 mm), was immersed in 30% nitric acid at 50 °C for 1 hour, washed with pure water, and dried (test piece of SUS304) was used.

[0142] [Example A-1] The [bis(difluorophosphoryl)imide]triethylammonium salt obtained in Synthesis Example 1 was dissolved in dimethyl carbonate (DMC) having a water content of 10 mass ppm or less to obtain a solution having a concentration of 20 mass%. The solution was transferred to a fluororesin container (PFA container manufactured by Fluorine Industry Co., Ltd.), and a test piece of SUS304 was further put in and completely immersed. In this state, after holding at 25 °C for 3 months or at 45 °C for 6 months, the Fe content in the solution was quantified. The results are shown in Table 1 together with the Fe content in the solution before immersing the test piece.

[0143] [Example A-2] The [bis(difluorophosphoryl)imide]lithium salt obtained in Synthesis Example 2 was dissolved in EMC with a water content of 10 ppm or less to prepare a 30% by mass solution. This solution was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. After being held at 25°C for 3 months or 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 1.

[0144] [Example A-3] The potassium salt [(trifluoromethanesulfonyl)(dichlorophosphoryl)imide] obtained in Synthesis Example 3 was dissolved in diethyl carbonate (DEC) with a water content of 10 ppm or less to prepare a 10% by mass solution. This solution was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. After being maintained at 25°C for 3 months or 45°C for 6 months, the Fe content in the solution was quantified. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 1.

[0145] [Example A-4] The EMC solution of the lithium [(fluorosulfonyl)(difluorophosphoryl)imide] obtained in Synthesis Example 4 was further concentrated under reduced pressure to a 30% by mass solution. This solution was transferred to a PFA container, and a SUS304 test piece was placed in it and completely immersed. After being held at 25°C for 3 months or 45°C for 6 months, the Fe content in the solution was quantified. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 1.

[0146] [Example A-5] To the EMC solution of the [(fluorosulfonyl)(difluorophosphoryl)imide]lithium salt obtained in Synthesis Example 4, ethylene carbonate (EC) with a water content of 10 ppm or less was added, and the solution was concentrated under reduced pressure to partially remove the EMC. This yielded a solution with a concentration of 30% by mass of [(fluorosulfonyl)(difluorophosphoryl)imide]lithium salt, an EMC content of 60% by volume in the non-aqueous solvent, and an EC content of 40% by volume in the non-aqueous solvent. The solution was transferred to a PFA container, and a SUS304 test piece was placed in it and completely immersed. After being held at 25°C for 3 months or 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 1.

[0147] [Comparative example A-1] The [bis(difluorophosphoryl)imide]triethylammonium salt obtained in Synthesis Example 1 was dissolved in propylene carbonate (PC) with a water content of 10 ppm or less by mass to prepare a 20% by mass solution. The same evaluation as in Example A-1 was performed using this solution. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 1.

[0148] [Comparative example A-2] The [bis(difluorophosphoryl)imide]lithium salt obtained in Synthesis Example 2 was dissolved in water with an EC of 10 ppm by mass or less to obtain a 30% by mass solution. The same evaluation as in Example A-1 was performed using this solution. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 1.

[0149] [Comparative example A-3] The potassium salt [(trifluoromethanesulfonyl)(dichlorophosphoryl)imide] obtained in Synthesis Example 3 was dissolved in water at an EC of 10 ppm by mass or less to obtain a 10% by mass solution. The same evaluation as in Example A-1 was performed using this solution. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 1.

[0150] [Comparative example A-4] To the EMC solution of the lithium salt of [(fluorosulfonyl)(difluorophosphoryl)imide] obtained in Synthesis Example 4, EC with a water content of 10 mass ppm or less was added, and the mixture was concentrated under reduced pressure to distill off EMC, obtaining an EC solution with a concentration of 30 mass%. Using this solution, the same evaluation as in Example A-1 was performed. The results are shown in Table 1 together with the Fe content in the solution before immersing the test piece.

[0151] [Comparative Example A-5] To the EMC solution of the lithium salt of [(fluorosulfonyl)(difluorophosphoryl)imide] obtained in Synthesis Example 4, EC with a water content of 10 mass ppm or less was added, and the mixture was concentrated under reduced pressure to distill off a part of EMC, obtaining a solution in which the concentration of the lithium salt of [(fluorosulfonyl)(difluorophosphoryl)imide] was 30 mass%, the content of EMC in the non-aqueous solvent was 40% by volume, and the content of EC in the non-aqueous solvent was 60% by volume. The solution was transferred to a PFA container, and a SUS304 test piece was further put in and completely immersed. In this state, after holding at 25°C for 3 months or at 45°C for 6 months, the Fe content in the solution was quantified. The results are shown in Table 1 together with the Fe content in the solution before immersing the test piece.

[0152] [Table 1]

[0153] In Table 1, "<2" indicates less than 2 mass ppm.

[0154] [Example A-6] The triethylammonium salt of [bis(difluorophosphoryl)imide] obtained in Synthesis Example 1 was dissolved in DMC with a water content of 10 mass ppm or less to obtain a solution with a concentration of 1 mass%. The solution was transferred to a PFA container, and a SUS304 test piece was further put in and completely immersed. In this state, after holding at 45°C for 6 months, the Fe content in the solution was quantified. The results are shown in Table 2 together with the Fe content in the solution before immersing the test piece.

[0155] [Example A-7] The [bis(difluorophosphoryl)imide]lithium salt obtained in Synthesis Example 2 was dissolved in EMC with a water content of 10 ppm or less to obtain a 1% by mass solution. This solution was transferred to a PFA container, and a SUS304 test piece was placed in it and completely immersed. After being held at 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 2.

[0156] [Example A-8] The potassium salt [(trifluoromethanesulfonyl)(dichlorophosphoryl)imide] obtained in Synthesis Example 3 was dissolved in DEC with a water content of 10 ppm or less to prepare a 1% by mass solution. This solution was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. After being maintained at 45°C for 6 months, the Fe content in the solution was quantified. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 2.

[0157] [Example A-9] An EMC solution of the lithium [(fluorosulfonyl)(difluorophosphoryl)imide] obtained in Synthesis Example 4 was prepared by adding EMC with a water content of 10 ppm or less to a 1% by mass solution. The solution was transferred to a PFA container, and a SUS304 test piece was placed in it and completely immersed. After being held at 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 2.

[0158] [Example A-10] To the EMC solution of the [(fluorosulfonyl)(difluorophosphoryl)imide]lithium salt obtained in Synthesis Example 4, EMC with a water content of 10 ppm or less and EC with a water content of 10 ppm or less were added to prepare a solution in which the concentration of [(fluorosulfonyl)(difluorophosphoryl)imide]lithium salt was 1% by mass, the EMC content in the non-aqueous solvent was 60% by volume, and the EC content in the non-aqueous solvent was 40% by volume. This solution was transferred to a PFA container, and a SUS304 test piece was placed in it and completely immersed. After being held at 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 2.

[0159] [Comparative example A-6] The [bis(difluorophosphoryl)imide]triethylammonium salt obtained in Synthesis Example 1 was dissolved in PC with a water content of 10 ppm or less to obtain a 1% by mass solution. This solution was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. The same evaluation as in Example A-6 was performed using this solution. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 2.

[0160] [Comparative example A-7] The [bis(difluorophosphoryl)imide]lithium salt obtained in Synthesis Example 2 was dissolved in water at an EC of 10 ppm by mass or less to obtain a 1% by mass solution. This solution was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. The same evaluation as in Example A-6 was performed using this solution. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 2.

[0161] [Comparative example A-8] The potassium salt [(trifluoromethanesulfonyl)(dichlorophosphoryl)imide] obtained in Synthesis Example 3 was dissolved in water at an EC of 10 ppm by mass or less to obtain a 1% by mass solution. This solution was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. The same evaluation as in Example A-6 was performed using this solution. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 2.

[0162] [Comparative example A-9] To the EC solution of the lithium [(fluorosulfonyl)(difluorophosphoryl)imide] obtained in Comparative Example A-4, EC with a water content of 10 ppm or less was added to prepare an EC solution with a concentration of 1% by mass. The same evaluation as in Example A-6 was performed using this solution. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 2.

[0163] [Comparative example A-10] To the EMC solution of the [(fluorosulfonyl)(difluorophosphoryl)imide]lithium salt obtained in Synthesis Example 4, EMC with a water content of 10 ppm or less and EC with a water content of 10 ppm or less were added to prepare a solution in which the concentration of [(fluorosulfonyl)(difluorophosphoryl)imide]lithium salt was 1% by mass, the EMC content in the non-aqueous solvent was 40% by volume, and the EC content in the non-aqueous solvent was 60% by volume. The same evaluation as in Example A-6 was performed using this solution. The results, along with the Fe content in the solution before immersion of the test piece, are shown in Table 2.

[0164] [Table 2]

[0165] In Table 2, "<2" indicates less than 2 ppm by mass.

[0166] [evaluation] The test was conducted by immersing SUS304 test pieces in the non-aqueous electrolytes described in each of the examples and comparative examples below, and then measuring the change in the iron atom content (Fe content) in the non-aqueous electrolyte before and after immersion.

[0167] [Example B-1] In a glove box with a dew point of -60°C or lower, while maintaining the internal temperature at 40°C or lower, a non-aqueous electrolyte was prepared such that the concentration of LiPF6 was 1.0 mol / L, the volume ratio of the non-aqueous solvent was EC:EMC:DMC = 25:45:30 (all with a water content of 10 ppm or less), and the concentration of the [bis(difluorophosphoryl)imide]triethylammonium salt obtained in Synthesis Example 1 was 3% by mass relative to the total volume of the non-aqueous electrolyte. The non-aqueous electrolyte was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. After being maintained at 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the non-aqueous electrolyte before immersion of the test piece, are shown in Table 3.

[0168] [Example B-2] In a glove box with a dew point of -60°C or lower, while maintaining the internal temperature at 40°C or lower, a non-aqueous electrolyte was prepared such that the concentration of LiPF6 was 1.0 mol / L, the volume ratio of the non-aqueous solvent was EC:EMC:DMC = 25:45:30 (all with a water content of 10 ppm or less), and the concentration of the [bis(difluorophosphoryl)imide]lithium salt obtained in Synthesis Example 2 was 3% by mass relative to the total volume of the non-aqueous electrolyte. The non-aqueous electrolyte was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. After being maintained at 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the non-aqueous electrolyte before immersion of the test piece, are shown in Table 3.

[0169] [Example B-3] In a glove box with a dew point of -60°C or lower, while maintaining the internal temperature at 40°C or lower, a non-aqueous electrolyte was prepared such that the concentration of LiPF6 was 1.0 mol / L, the volume ratio of the non-aqueous solvent was EC:EMC:DMC = 25:45:30 (all with a water content of 10 ppm or less), and the concentration of the potassium salt [(trifluoromethanesulfonyl)(dichlorophosphoryl)imide] obtained in Synthesis Example 3 was 3% by mass relative to the total volume of the non-aqueous electrolyte. The non-aqueous electrolyte was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. After being maintained at 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the non-aqueous electrolyte before immersion of the test piece, are shown in Table 3.

[0170] [Example B-4] In a glove box with a dew point of -60°C or lower, while maintaining the internal temperature at 40°C or lower, a non-aqueous electrolyte was prepared such that the concentration of LiPF6 was 1.0 mol / L, the volume ratio of the non-aqueous solvent was EC:EMC:DMC = 25:45:30 (all with a water content of 10 ppm or less), and the concentration of the lithium [(fluorosulfonyl)(difluorophosphoryl)imide] salt obtained in Synthesis Example 4 was 3% by mass relative to the total volume of the non-aqueous electrolyte. The non-aqueous electrolyte was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. After being maintained at 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the non-aqueous electrolyte before immersion of the test piece, are shown in Table 3.

[0171] [Comparative example B-1] In a glove box with a dew point of -60°C or lower, while maintaining the internal temperature at 40°C or lower, a non-aqueous electrolyte was prepared such that the concentration of LiPF6 was 1.0 mol / L, the volume ratio of the non-aqueous solvent was EC:EMC = 60:40 (both with a water content of 10 ppm or less), and the concentration of the [bis(difluorophosphoryl)imide]triethylammonium salt obtained in Synthesis Example 1 was 3% by mass relative to the total volume of the non-aqueous electrolyte. The non-aqueous electrolyte was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. After being maintained at 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the non-aqueous electrolyte before immersion of the test piece, are shown in Table 3.

[0172] [Comparative example B-2] In a glove box with a dew point of -60°C or lower, while maintaining the internal temperature at 40°C or lower, a non-aqueous electrolyte was prepared such that the concentration of LiPF6 was 1.0 mol / L, the volume ratio of the non-aqueous solvent was EC:EMC = 60:40 (both with less than 10 ppm of water by mass), and the concentration of the [bis(difluorophosphoryl)imide]lithium salt obtained in Synthesis Example 2 was 3% by mass relative to the total volume of the non-aqueous electrolyte. The non-aqueous electrolyte was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. After being maintained at 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the non-aqueous electrolyte before immersion of the test piece, are shown in Table 3.

[0173] [Comparative example B-3] In a glove box with a dew point of -60°C or lower, while maintaining the internal temperature at 40°C or lower, a non-aqueous electrolyte was prepared such that the concentration of LiPF6 was 1.0 mol / L, the volume ratio of the non-aqueous solvent was EC:EMC = 60:40 (both with a water content of 10 ppm or less), and the concentration of the potassium salt [(trifluoromethanesulfonyl)(dichlorophosphoryl)imide] obtained in Synthesis Example 3 was 3% by mass relative to the total volume of the non-aqueous electrolyte. The non-aqueous electrolyte was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. After being maintained at 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the non-aqueous electrolyte before immersion of the test piece, are shown in Table 3.

[0174] [Comparative example B-4] In a glove box with a dew point of -60°C or lower, while maintaining the internal temperature at 40°C or lower, a non-aqueous electrolyte was prepared such that the concentration of LiPF6 was 1.0 mol / L, the volume ratio of the non-aqueous solvent was EC:EMC = 60:40 (both with a water content of 10 ppm or less), and the concentration of the lithium [(fluorosulfonyl)(difluorophosphoryl)imide] obtained in Synthesis Example 4 was 3% by mass relative to the total volume of the non-aqueous electrolyte. The non-aqueous electrolyte was transferred to a PFA container, and a SUS304 test piece was then placed in it and completely immersed. After being maintained at 45°C for 6 months in this state, the Fe content in the solution was quantified. The results, along with the Fe content in the non-aqueous electrolyte before immersion of the test piece, are shown in Table 3.

[0175] [Table 3]

[0176] In Table 3, "<2" indicates less than 2 ppm by mass.

[0177] As is clear from Tables 1-3, the non-aqueous solutions of this disclosure and the non-aqueous solutions used in the retention method of this disclosure are less likely to cause corrosion even when in contact with austenitic stainless steel.

[0178] [Example C-1] Using the non-aqueous electrolyte obtained in Example B-2, a non-aqueous battery was fabricated with a positive electrode using SUS304 as the current collector, as the wetted component containing austenitic stainless steel.

[0179] (Fabrication of the positive electrode) LiNi 0.8 Co 0.1 Mn 0.1A slurry solution was prepared by mixing 92% by mass of O2, 4.5% by mass of acetylene black as a conductive agent, and 3.5% by mass of PVDF as a binder. N-methyl-2-pyrrolidone was then added as a solvent in an amount of 55% by mass relative to the total mass of the positive electrode active material, conductive agent, and binder. This slurry solution was applied to a SUS304 foil, which served as the positive electrode current collector, and dried at 150°C for 12 hours to obtain a test NCM811 positive electrode with a positive electrode active material layer formed on the current collector.

[0180] (Fabrication of the negative electrode) A slurry solution was prepared by mixing 85% by mass of artificial graphite powder with 7% by mass of nanosilicon, 3% by mass of conductive material (HS-100), 2% by mass of carbon nanofiber (VGCF), 2% by mass of styrene-butadiene rubber, 1% by mass of sodium carboxymethylcellulose, and water. This slurry solution was applied to a copper foil, which served as the negative electrode current collector, and dried at 100°C for 12 hours to obtain a test silicon-containing graphite negative electrode with a negative electrode active material layer formed on the current collector.

[0181] A 50mAh cell with an aluminum laminate casing was assembled by arranging the above-mentioned positive and negative electrodes opposite each other and placing a polyethylene separator impregnated with the non-aqueous electrolyte obtained in Example B-2 between them.

[0182] When charge and discharge tests were conducted using the above-mentioned cell, it was confirmed that there were no adverse effects from corrosion of the electrode current collector (SUS304) and that charging and discharging could be performed without any problems. Therefore, it can be seen that a non-aqueous cell can be obtained that is less likely to cause corrosion in the wetted parts, even if austenitic stainless steel is included. [Industrial applicability]

[0183] This disclosure provides a non-aqueous solution that is less likely to cause corrosion even when in contact with austenitic stainless steel, a method for holding the same, and a non-aqueous battery that is less likely to cause corrosion to austenitic stainless steel even if it is included as a wetted component.

[0184] Although this disclosure has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of this disclosure. This application is based on Japanese Patent Application No. 2021-152601 filed on September 17, 2021, the contents of which are incorporated herein by reference.

Claims

1. A non-aqueous solution in contact with austenitic stainless steel, The aforementioned non-aqueous solution comprises a non-aqueous solvent and an imid acid or imidate salt represented by the following general formula [1], A non-aqueous solution in which the non-aqueous solvent having a relative permittivity (at 25°C) of 10 or less is present in a volume of 50 to 100%. 【Chemistry 1】 [In general formula [1], X １ , X ２ Each of these independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and at least one of the following can be present in the organic group: a fluorine atom, an oxygen atom, a nitrogen atom, and an unsaturated bond. Z is -P (=O) <, -S (=O) ２ It represents - or -C (=O)-. a is 0 or 1. When Z represents -P (=O) <, a is 1 and Z is -S (=O). ２ When a represents - or -C (=O)-, a is 0. R １ , R ２ Each of these independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkenyl group, a C2-C10 alkenyloxy group, a C2-C10 alkynyl group, a C2-C10 alkynyloxy group, a C3-C10 cycloalkyl group, a C3-C10 cycloalkoxy group, a C3-C10 cycloalkenyl group, a C3-C10 cycloalkenyloxy group, a C6-C10 aryl group, and a C6-C10 aryloxy group, and the organic group may also contain at least one selected from a fluorine atom, an oxygen atom, and an unsaturated bond. M ｍ＋ [where m represents a proton, alkali metal cation, alkaline earth metal cation, or onium cation, and m represents the valency of the cation.]

2. The non-aqueous solution according to claim 1, wherein the non-aqueous solvent having a relative permittivity of 10 or less (at 25°C) is at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, methyl acetate, ethyl acetate, ethyl propionate, 1,2-dimethoxyethane, and diethylene glycol dimethyl ether.

3. The non-aqueous solution according to claim 1 or 2, wherein the concentration of the imidic acid or imidate salt represented by the general formula [1] in the non-aqueous solution is 1 to 90% by mass.

4. A method for holding a non-aqueous solution in a wetted member, including an austenitic stainless steel, The aforementioned non-aqueous solution comprises a non-aqueous solvent and an imid acid or imidate salt represented by the following general formula [1], A storage method wherein the non-aqueous solvent has a relative permittivity of 10 or less (at 25°C) and its content in the non-aqueous solvent is 50 to 100% by volume. 【Chemistry 2】 In general formula [1], X １ , X ２ each independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and at least one selected from fluorine atoms, oxygen atoms, nitrogen atoms, and unsaturated bonds may be present in the organic group. Z is -P (=O) <, -S (=O) ２ It represents - or -C (=O)-. a is 0 or 1. When Z represents -P (=O) <, a is 1 and Z is -S (=O). ２ When a represents - or -C (=O)-, a is 0. R １ , R ２ Each of these independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkenyl group, a C2-C10 alkenyloxy group, a C2-C10 alkynyl group, a C2-C10 alkynyloxy group, a C3-C10 cycloalkyl group, a C3-C10 cycloalkoxy group, a C3-C10 cycloalkenyl group, a C3-C10 cycloalkenyloxy group, a C6-C10 aryl group, and a C6-C10 aryloxy group, and the organic group may also contain at least one selected from a fluorine atom, an oxygen atom, and an unsaturated bond. M ｍ＋ [where m represents a proton, alkali metal cation, alkaline earth metal cation, or onium cation, and m represents the valency of the cation.]

5. The retention method according to claim 4, wherein the non-aqueous solvent having a relative permittivity of 10 or less (at 25°C) is at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, methyl acetate, ethyl acetate, ethyl propionate, 1,2-dimethoxyethane, and diethylene glycol dimethyl ether.

6. The retention method according to claim 4 or 5, wherein the concentration of the imido acid or imido salt represented by the general formula [1] in the non-aqueous solution is 1 to 90% by mass.

7. A non-aqueous battery comprising a wetted component including austenitic stainless steel, and a non-aqueous electrolyte in contact with the wetted component, The non-aqueous electrolyte comprises a non-aqueous solvent and an imid acid or imidate salt represented by the following general formula [1], A non-aqueous battery in which the non-aqueous solvent having a relative permittivity (at 25°C) of 10 or less is contained in 50 to 100% by volume. 【Transformation 3】 [In general formula [1], X １ , X ２ Each of these independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and at least one of the following can be present in the organic group: a fluorine atom, an oxygen atom, a nitrogen atom, and an unsaturated bond. Z is -P (=O) <, -S (=O) ２ It represents - or -C (=O)-. a is 0 or 1. When Z represents -P (=O) <, a is 1 and Z is -S (=O). ２ When a represents - or -C (=O)-, a is 0. R １ , R ２ Each of these independently represents a chlorine atom, a fluorine atom, or an organic group selected from the group consisting of a C1-C10 alkyl group, a C1-C10 alkoxy group, a C2-C10 alkenyl group, a C2-C10 alkenyloxy group, a C2-C10 alkynyl group, a C2-C10 alkynyloxy group, a C3-C10 cycloalkyl group, a C3-C10 cycloalkoxy group, a C3-C10 cycloalkenyl group, a C3-C10 cycloalkenyloxy group, a C6-C10 aryl group, and a C6-C10 aryloxy group, and the organic group may also contain at least one selected from a fluorine atom, an oxygen atom, and an unsaturated bond. M ｍ＋ [where m represents a proton, alkali metal cation, alkaline earth metal cation, or onium cation, and m represents the valency of the cation.]

8. The non-aqueous battery according to claim 7, wherein the non-aqueous solvent having a relative permittivity of 10 or less (at 25°C) is at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, methyl acetate, ethyl acetate, ethyl propionate, 1,2-dimethoxyethane, and diethylene glycol dimethyl ether.

9. The non-aqueous battery according to claim 7 or 8, wherein the concentration of the imid acid or imidate salt represented by the general formula [1] in the non-aqueous electrolyte is 0.1 to 10% by mass.

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