Battery electrolyte and redox flow battery

Abstract

To provide an electrolyte solution for a battery, which has high solubility of an electrolyte, can suppress precipitation of the electrolyte, and has low resistance as an electrolyte solution.SOLUTION: A battery electrolyte contains an anion that forms a redox pair, a cation (A), and water, and satisfies all of the following conditions (1) to (4). (1) The cation (A) contains only one cation (A1) having a membrane resistance of 1 Ω cm2 or less, and at least one organic cation (A2) having a membrane resistance of 5 Ω cm2 or more. (2) A 0.01 mol / L aqueous solution of a salt of the cation (A1) and a chloride ion has a pH of 3 to 8. (3) A 0.01 mol / L aqueous solution of a salt of the organic cation (A2) and a chloride ion has a pH of 3 to 10. (4) The concentration of the cation (A1) is 1 mol / L or more and less than 5 mol / L, and the concentration of the organic cation (A2) is 1 mol / L or more and less than 4 mol / L.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electrolyte for a battery and a redox flow battery.

Background Art

[0002] As batteries using redox couples, redox flow batteries and thermochemical batteries are known. In particular, redox flow batteries that supply an electrolyte to an electrode to perform a battery reaction have attracted attention as batteries suitable for increasing the capacity.

[0003] In Non-Patent Document 1, K3[Fe(CN)6] / K4[Fe(CN)6] is used as an electrolyte. In Non-Patent Document 1, KCl and KOH are examined as supporting salts, and it is described that the solubility of K3[Fe(CN)6] / K4[Fe(CN)6] is slightly improved by making the electrolyte a strong base with KOH.

[0004] In Patent Document 1, compared with the case of using K3[Fe(CN)6] / K4[Fe(CN)6] or Na3[Fe(CN)6] / Na4[Fe(CN)6] alone, by mixing potassium ions and sodium ions, the solubility of [Fe(CN)6] 3- / [Fe(CN)6] 4- is described as being improved.

[0005] In Non-Patent Document 2, by using various organic cations as the cations that become the counterions of [Fe(CN)6] 3- and [Fe(CN)6] 4- instead of the conventional alkali metals, it is described that the solubility of the electrolyte is improved with specific organic cations compared to the conventional alkali metals.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Non-Patent Documents

[0007] [Non-Patent Document 1] Luo, J., Sam, A., Hu, B., DeBruler, C., Wei, X., Wang, W., & Liu, T. L. (2017). Unraveling pH dependent cycling stability of ferricyanide / ferrocyanide in redox flow batteries. Nano Energy, 42, 215-221. [Non-Patent Document 2] Waters, S. E., Thurston, J. R., Armstrong, R. W., Robb, B. H., Marshak, M. P., & Reber, D. (2022). Holistic design principles for flow batteries: Cation dependent membrane resistance and active species solubility. Journal of Power Sources, 520, 230877. [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] From the perspective of improving the performance of redox flow batteries, it is important to make the positive electrode side electrolyte have high concentration, low resistance, high reaction potential, and low precipitation risk.

[0009] In Non-Patent Document 1, K3[Fe(CN)6] / K4[Fe(CN)6] is used as an electrolyte, but when the cation ion is only potassium ion, the solubility of the electrolyte is low. Non-Patent Document 1 describes that the solubility of K3[Fe(CN)6] / K4[Fe(CN)6] is slightly improved by using KOH as a supporting salt, but the pH becomes strongly basic, and side reactions such as the desorption of the cyano group, which is a ligand of the redox species, cause the durability to deteriorate.

[0010] When potassium ions and sodium ions are mixed as cations as in Patent Document 1, during charge and discharge, sodium ions move preferentially over potassium ions in the permeation of ions in the cation exchange membrane. Therefore, the potassium ion / sodium ion ratio in the positive electrode electrolyte changes and the potassium ion ratio increases. As a result, the solubility of the anion that forms the redox pair decreases, and the risk of electrolyte precipitation increases.

[0011] When an organic cation is used as a cation as in Non-Patent Document 2, since the organic cation hardly permeates the cation exchange membrane, the resistance of the electrolyte increases.

[0012] The present invention has been made to solve the above problems, and an object thereof is to provide a battery electrolyte having high solubility of the electrolyte, capable of suppressing precipitation of the electrolyte, and having low resistance as an electrolyte.

Means for Solving the Problems

[0013] As a result of intensive studies to solve the above problems, the present inventors have reached the present invention. The battery electrolyte according to the first aspect of the present invention is a battery electrolyte containing an anion that forms a redox pair, a cation (A), and water, and satisfies all of the following conditions (1) to (4). (1) The above cation (A) contains only one kind of cation (A1) having a membrane resistance of 1 Ωcm 2 or less and at least one kind of organic cation (A2) having a membrane resistance of 5 Ωcm 2 or more; (2) The pH of a 0.01 mol / L aqueous solution of the salt of the above cation (A1) and chloride ions is 3 to 8; (3) The pH of a 0.01 mol / L aqueous solution of the salt of the above organic cation (A2) and chloride ions is 3 to 10; (4) The concentration of the above cation (A1) is 1 mol / L or more and less than 5 mol / L, and the concentration of the above organic cation (A2) is 1 mol / L or more and less than 4 mol / L.

[0014] The electrolytic solution for a battery according to the second aspect of the present invention is an electrolytic solution for a battery containing an anion serving as a redox pair, a cation (A), and water. The cation (A) is Li + ion, Na + ion, K + ion, and NH4 + ion, and contains only one kind of cation (A1) selected from the group consisting of these ions, and at least one or more organic cations (A2) selected from the group consisting of choline cation, tetramethylammonium cation, tetraethylammonium cation, diethylmethyl-(2-methoxyethyl)ammonium cation, triethylmethylammonium cation, and 1-ethyl-3-methylimidazolium cation. The concentration of the cation (A1) is 1 mol / L or more and less than 5 mol / L, and the concentration of the organic cation (A2) is 1 mol / L or more and less than 4 mol / L.

[0015] The redox flow battery of the present invention contains the electrolytic solution for a battery of the present invention.

Advantages of the Invention

[0016] According to the present invention, it is possible to provide an electrolytic solution for a battery having high solubility of the electrolyte, capable of suppressing precipitation of the electrolyte, and having low resistance as an electrolytic solution.

Brief Description of the Drawings

[0017]

Figure 1

Embodiments for Carrying Out the Invention

[0018] Hereinafter, the present invention will be described in detail. The present invention relates to an electrolytic solution for a battery and a redox flow battery.

[0019] [Electrolytic Solution for a Battery] In the following description, when each aspect is not particularly distinguished, it is simply referred to as "the electrolyte for a battery of the present invention" or "the electrolyte for a battery". The electrolyte for a battery according to the first aspect of the present invention is an electrolyte for a battery containing an anion serving as a redox pair, a cation (A), and water, and satisfies all of the following conditions (1) to (4). (1) The above cation (A) contains only one kind of cation (A1) having a membrane resistance of 1 Ωcm 2 or less and at least one kind of organic cation (A2) having a membrane resistance of 5 Ωcm 2 or more; (2) The pH of a 0.01 mol / L aqueous solution of the salt of the above cation (A1) and chloride ions is 3 to 8; (3) The pH of a 0.01 mol / L aqueous solution of the salt of the above organic cation (A2) and chloride ions is 3 to 10; (4) The concentration of the above cation (A1) is 1 mol / L or more and less than 5 mol / L, and the concentration of the above organic cation (A2) is 1 mol / L or more and less than 4 mol / L.

[0020] The electrolyte for a battery of the present invention contains an anion serving as a redox pair, a cation (A), and water.

[0021] First, the anion serving as a redox pair will be described. The anion serving as a redox pair means a pair consisting of two types of ions capable of undergoing a redox reaction.

[0022] Examples of the anion include ferricyanide ion and ferrocyanide ion [Fe(CN)6 3- / [Fe(CN)6 4- , those obtained by substituting the ligands of ferricyanide ion and ferrocyanide ion, bromide ion and tribromide ion [Br - / [Br 3- , iodide ion and triiodide ion [I - / [I 3- , hexacyanidoruthenium(III) ion and hexacyanidoruthenium(II) ion [Ru(CN)6 3- / [Ru(CN)6 4- Examples include The anions that form the redox pair are preferably ferricyanide ions and ferrocyanide ions.

[0023] The electrolyte solution for a battery of the present invention may contain anions other than the anions that form the redox pair. The anions other than the anions that form the redox pair are not particularly limited. For example, chloride ions [Cl - etc. may be mentioned. Chloride ions may be contained by adding at least one electrolyte selected from the group consisting of LiCl, KCl, NaCl, and NH4Cl to the electrolyte solution for a battery as a supporting salt.

[0024] Next, the cation (A) will be described. The cation (A) contains only one kind of cation (A1) and at least one or more kinds of organic cations (A2).

[0025] The cation (A1) has a membrane resistance of 1 Ωcm 2 or less. The cation (A1) may have a membrane resistance of 0.3 Ωcm 2 or more and 1 Ωcm 2 or less. In the present invention, the membrane resistance of the cation is measured by the following method. When the membrane resistance of the cation is small, the cation easily passes through the cation exchange membrane.

[0026] The membrane resistance of the cation in the present invention will be described below. The membrane resistance of the cation in the present invention refers to the value described in the column of "H2O Soaked N212" in Table 1 of Non-Patent Document 2 (Waters, S. E., et al (2022) Journal of Power Sources, 520, 230877.). The membrane resistance of the cation in the present invention is measured in the same manner as the value described in the column of "H2O Soaked N212" in Table 1 of Non-Patent Document 2. The 1M chloride ion electrolyte solution of the cation to be measured and Nafion that has been pretreated by immersion in deionized water for 48 hours TMBy performing electrochemical impedance spectroscopy (EIS) on a battery cell having a 212 membrane, the membrane resistance of the cation in the present invention is measured by measuring the resistance per unit area of the cation dependence of the redox flow battery. The specific measurement method of the membrane resistance of the cation in the present invention is described below.

[0027] As the battery cell in the measurement method of the membrane resistance of the cation, a 5 cm single cell flow battery that can be purchased from FUEL CELL TECHNOLOGIES, INC. is used. This single cell flow battery has an acid battery configuration, and the tube carrying the electrolyte supplies the electrolyte directly to the graphite flow plate without contacting the aluminum or stainless steel battery parts. The flow plate is composed of a POCO graphite block having one serpentine flow path of 5 cm. 2 A 20 ml glass scintillation vial capped with a partition with holes drilled to fit 1 / 8 inch OD PFA inlet and outlet tubes contains a 1M chloride ion electrolyte of the cation to be measured. The Savillex 60 ml column, component container, flat interior, 1.5 inch MNPT, PFA container are filled with a 1M chloride ion electrolyte of the cation to be measured and sparged with argon for 20 minutes before use. The electrolyte is passed in and out of the flow cell at a rate of 60 ml min using a two-channel peristaltic pump (manufactured by Cole-Parmer Instrument) using Masterflex C-Flex ULTRA L / S 16 tubing coupled to 1 / 8 inch OD, 1 / 16 inch ID PFA tubing and PFA compression fittings. The flow cell experiment is performed using a Gamry Interface 5000 potentiostat / galvanostat. 2 -1

[0028] Nafion TMThe 212 membrane (thickness 50 μm, 3 cm × 3 cm) used is pretreated by immersing it in deionized water for 48 hours. Five stacked sheets of GDL 39 AA carbon paper (manufactured by SGL Carbon) (each thickness 280 μm, 5 cm 2 ) are dried in air at 150 °C for 12 hours and used on each side together with a 0.04-inch PTFE gasket that provides 27% membrane compression. The cell is bolted and tightened with a torque wrench set to 10 N·m.

[0029] The target 1 M electrolyte (5 ml) is flushed through both sides of the redox flow battery. Then, 10 ml of unused 1 M electrolyte is poured into both sides of the cell. The flow is stopped for the potentiostatic EIS measurement. The initial DC voltage is set to 0 V with respect to the open circuit potential with an AC voltage amplitude of 10 mVrms. EIS data is collected in the frequency range of 100 kHz - 10 Hz at a rate of 10 points / decade. Then, after flowing the electrolyte for 10 seconds, the experiment is repeated three times in total for each electrolyte.

[0030] The resistance value is extracted from the generated Nyquist plot by fitting the data to a model circuit. The extracted impedance is multiplied by the electrode area (5 cm 2 ) to obtain the membrane resistance in units of Ω cm 2 . The membrane resistance in units of Ω cm 2 obtained by the above method is the membrane resistance of the cation in the present invention.

[0031] The pH of a 0.01 mol / L aqueous solution of the salt of cation (A1) and chloride ions is 3 - 8. When the pH of the 0.01 mol / L aqueous solution of the salt of cation (A1) and chloride ions is within the above range, the pH of the battery electrolyte does not become too low, so the stability of the anion serving as the redox pair is improved. For example, when the anion serving as the redox pair is ferricyanide ion and ferrocyanide ion [Fe(CN)6 3- / [Fe(CN)6 4- , there is a risk of generating HCN as a side reaction when the pH of the battery electrolyte is low. In the present invention, the pH of the aqueous solution means the pH at 25°C. The pH can be measured using a commercially available pH meter. For the preparation of the aqueous solution used for the measurement of pH, ion-exchanged water is used.

[0032] In the electrolyte for a battery of the present invention, the concentration of the cation (A1) is 1 mol / L or more and less than 5 mol / L. In the electrolyte for a battery of the present invention, the concentration of the cation (A1) may be 1.5 mol / L or more and less than 4 mol / L.

[0033] The concentration of the cation (A1) does not only mean the concentration of the cation (A1) that serves as the counter ion of the anion forming the redox pair. That is, the concentration of the cation (A1) means the concentration including the cation (A1) added as a salt with an anion other than the anion forming the redox pair. For example, when the cation (A1) that serves as the counter ion of the anion forming the redox pair is Li + ion, and further LiCl is added as a supporting salt to the electrolyte for a battery, the concentration of the cation (A1) means the concentration including both the Li + ion and the Li + ion derived from LiCl. All of the cation (A1) may be derived from a salt with an anion other than the anion forming the redox pair.

[0034] The electrolyte for a battery of the present invention contains only one kind of cation (A1). When the electrolyte for a battery contains only one kind of cation (A1), the dissolution stability during charge and discharge is improved compared to the case where two or more kinds of cations (A1) are contained, so that the risk of precipitation of the electrolyte can be reduced.

[0035] The cation (A1) is + Li + ion, Na + ion, K + ion, or NH4

[0036] An example of the membrane resistance of the cation (A1) exemplified above is as follows. Li + Membrane resistance of ions: 0.9 Ωcm 2 Na + Membrane resistance of ions: 0.7 Ωcm 2 K + Membrane resistance of ions: 0.9 Ωcm 2 NH4 + Membrane resistance of ions: 0.6 Ωcm 2

[0037] An example of the pH of a 0.01 mol / L aqueous solution of the salt of the cation (A1) and chloride ions exemplified above is as follows. Li + pH of 0.01 mol / L aqueous solution of the salt of ions and chloride ions: 7.7 Na + pH of 0.01 mol / L aqueous solution of the salt of ions and chloride ions: 7.3 K + pH of 0.01 mol / L aqueous solution of the salt of ions and chloride ions: 7.3 NH4 + pH of 0.01 mol / L aqueous solution of the salt of ions and chloride ions: 6.2

[0038] The cation (A1) is more preferably one selected from the group consisting of Li + ions and K + ions. From the viewpoint of improving the solubility of the anion that forms a redox pair, K + ions are even more preferable, and from the viewpoint of reducing the resistance of the electrolyte, Li + ions are even more preferable.

[0039] Hereinafter, the organic cation (A2) will be described. The organic cation means the cation of an organic compound.

[0040] The organic cation (A2) has a membrane resistance of 5 Ωcm 2The above is the case. The organic cation (A2) has a membrane resistance of 5 Ωcm 2 or more and 100 Ωcm 2 or less, and may also be 5 Ωcm 2 or more and 30 Ωcm 2 or less. The membrane resistance of the organic cation (A2) is measured in the same manner as the membrane resistance of the cation (A1).

[0041] The pH of a 0.01 mol / L aqueous solution of the salt of the organic cation (A2) and chloride ions is 3 to 10. When the pH of a 0.01 mol / L aqueous solution of the salt of the organic cation (A2) and chloride ions is within the above range, the pH of the electrolyte for the battery does not become too low, so the stability of the anion serving as the redox pair is improved.

[0042] In the electrolyte for the battery of the present invention, the concentration of the organic cation (A2) is 1 mol / L or more and less than 4 mol / L. In the electrolyte for the battery of the present invention, the concentration of the organic cation (A2) may be 1.5 mol / L or more and less than 3.5 mol / L.

[0043] The concentration of the organic cation (A2) means the total concentration of the organic cation (A2) contained in the electrolyte for the battery, and does not only mean the concentration of the organic cation (A2) that serves as the counter ion of the anion serving as the redox pair. That is, the concentration of the organic cation (A2) means the concentration including the organic cation (A2) added as a salt with an anion other than the anion serving as the redox pair.

[0044] The electrolyte for the battery of the present invention may contain two or more organic cations (A2). When the electrolyte for the battery contains two or more organic cations (A2), the concentration of the organic cation (A2) means the sum of the concentrations of the respective organic cations (A2).

[0045] From the perspective of improving the solubility of the anion that forms the redox pair, the organic cation (A2) preferably has a molecular weight of 200 or less. The organic cation (A2) may have a molecular weight of 100 or more and 200 or less. The molecular weight of the organic cation (A2) is calculated from the ionic formula of the organic cation (A2). When the electrolyte for a battery contains two or more organic cations (A2), the molecular weight of all the organic cations (A2) may be 200 or less, or may be 100 or more and 200 or less.

[0046] The organic cation (A2) may contain an organic cation (A21) having a cyclic structure. In the organic cation (A21) having a cyclic structure, the cyclic structure is not particularly limited and may be, for example, a 5-membered ring or a 6-membered ring. Examples of the organic cation (A21) having a cyclic structure include cations having an imidazole group such as 1-ethyl-3-methylimidazolium cation. The organic cation (A2) may contain only the organic cation (A21) having a cyclic structure.

[0047] The organic cation (A2) may contain an organic cation (A22) having no cyclic structure. Examples of the organic cation (A22) having no cyclic structure include choline cation (also referred to as (2-hydroxyethyl)trimethylammonium cation), tetramethylammonium cation, tetraethylammonium cation, diethylmethyl-(2-methoxyethyl)ammonium cation, and triethylmethylammonium cation. The organic cation (A2) may contain only the organic cation (A22) having no cyclic structure.

[0048] The organic cation (A2) is preferably at least one selected from the group consisting of choline cation, tetramethylammonium cation, tetraethylammonium cation, diethylmethyl-(2-methoxyethyl)ammonium cation, triethylmethylammonium cation, and 1-ethyl-3-methylimidazolium cation, and more preferably at least one selected from the group consisting of choline cation, tetramethylammonium cation, tetraethylammonium cation, diethylmethyl-(2-methoxyethyl)ammonium cation, and triethylmethylammonium cation.

[0049] An example of the membrane resistance of the organic cation (A2) exemplified above is as follows. Membrane resistance of choline cation: 10.0 Ωcm 2 Membrane resistance of tetramethylammonium cation: 11.6 Ωcm 2 Membrane resistance of tetraethylammonium cation: 12.0 Ωcm 2 Membrane resistance of diethylmethyl-(2-methoxyethyl)ammonium cation: 14.5 Ωcm 2 Membrane resistance of triethylmethylammonium cation: 12.5 Ωcm 2 Membrane resistance of 1-ethyl-3-methylimidazolium cation: 18.5 Ωcm 2

[0050] An example of the pH of a 0.01 mol / L aqueous solution of the salt of the organic cation (A2) and chloride ion exemplified above is as follows. pH of a 0.01 mol / L aqueous solution of the salt of choline cation and chloride ion: 7.9 pH of a 0.01 mol / L aqueous solution of the salt of tetramethylammonium cation and chloride ion: 7.3 pH of a 0.01 mol / L aqueous solution of the salt of tetraethylammonium cation and chloride ion: 7.7 pH of a 0.01 mol / L aqueous solution of the salt of diethylmethyl-(2-methoxyethyl)ammonium cation and chloride ion: 8.0 pH of a 0.01 mol / L aqueous solution of the salt of triethylmethylammonium cation and chloride ion: 7.6 pH of a 0.01 mol / L aqueous solution of the salt of 1-ethyl-3-methylimidazolium cation and chloride ion: 7.8

[0051] The organic cation (A2) is more preferably one selected from the group consisting of choline cation, diethylmethyl-(2-methoxyethyl)ammonium cation and 1-ethyl-3-methylimidazolium cation, and still more preferably choline cation.

[0052] Examples of the combination of the cation (A1), the organic cation (A2) and the anion include the following examples. The examples of the combination are shown in the order of cation (A1) / organic cation (A2) / anion. K + Ion / choline cation / ferricyanide ion and ferrocyanide ion K + Ion / 1-ethyl-3-methylimidazolium cation / ferricyanide ion and ferrocyanide ion K + Ion / choline cation and 1-ethyl-3-methylimidazolium cation / ferricyanide ion and ferrocyanide ion K + Ion / diethylmethyl-(2-methoxyethyl)ammonium cation / ferricyanide ion and ferrocyanide ion Li + Ion / choline cation / ferricyanide ion and ferrocyanide ion

[0053] Hereinafter, the effect of the electrolyte for a battery containing the cation (A1) and the organic cation (A2) will be described. When the electrolyte for a battery contains a cation (A1) and an organic cation (A2), the common ion effect is reduced, so that the solubility of the anion serving as the redox pair can be improved. Moreover, since the cation (A1) has a low membrane resistance and easily permeates through the cation exchange membrane, when used as the electrolyte for the positive electrode of a redox flow battery, the resistance of the redox flow battery can be lowered. Further, even when the organic cation (A2) in the positive electrode solution increases due to the compositional change during charge and discharge, the solubility of the electrolyte is high, so that the risk of precipitation of the electrolyte can be reduced.

[0054] From the viewpoint of improving the reaction potential, the ratio {A2 / (A1 + A2)} of the molar concentration of the organic cation (A2) to the total of the molar concentration of the cation (A1) and the molar concentration of the organic cation (A2) is less than 80%, preferably less than 70%, and more preferably less than 55%.

[0055] From the viewpoint of improving the reaction potential, the organic cation (A2) preferably contains only an organic cation (A22) having no cyclic structure. When the organic cation (A2) contains only an organic cation (A22) having no cyclic structure, from the viewpoint of improving the reaction potential, the ratio {A22 / (A1 + A2)} of the molar concentration of the organic cation (A22) having no cyclic structure to the total of the molar concentration of the cation (A1) and the molar concentration of the organic cation (A2) is less than 80%, preferably less than 70%, and more preferably less than 55%.

[0056] When the organic cation (A2) contains an organic cation (A21) having a cyclic structure, from the viewpoint of improving the reaction potential, the ratio {A21 / (A1 + A2)} of the molar concentration of the organic cation (A21) having a cyclic structure to the total of the molar concentration of the cation (A1) and the molar concentration of the organic cation (A2) is preferably less than 55%, and more preferably less than 50%.

[0057] When the organic cation (A2) contains only the organic cation (A21) having a cyclic structure, from the viewpoint of improving the reaction potential, the ratio {A21 / (A1+A2)} of the molar concentration of the organic cation (A21) having a cyclic structure to the total of the molar concentration of the cation (A1) and the molar concentration of the organic cation (A2) is preferably less than 55%, more preferably less than 50%.

[0058] From the viewpoint of improving the reaction potential, the organic cation (A2) preferably contains only the organic cation (A22) having no cyclic structure. Alternatively, the organic cation (A2) contains the organic cation (A21) having a cyclic structure, and the ratio {A21 / (A1+A2)} of the molar concentration of the organic cation (A21) having a cyclic structure to the total of the molar concentration of the cation (A1) and the molar concentration of the organic cation (A2) is preferably less than 55%.

[0059] The electrolyte for a battery of the present invention contains water. The electrolyte for a battery may contain an aqueous solvent as a solvent. Examples of the aqueous solvent include water and aqueous solutions of alcohols (such as ethylene glycol).

[0060] The electrolyte for a battery according to the second aspect of the present invention is an electrolyte for a battery containing an anion serving as a redox pair, a cation (A), and water, and the cation (A) is Li + ion, Na + ion, K + ion, and NH4 + ion, and contains only one kind of cation (A1) selected from the group consisting of them and at least one kind of organic cation (A2) selected from the group consisting of choline cation, tetramethylammonium cation, tetraethylammonium cation, diethylmethyl-(2-methoxyethyl)ammonium cation, triethylmethylammonium cation, and 1-ethyl-3-methylimidazolium cation, the concentration of the cation (A1) is 1 mol / L or more and less than 5 mol / L, and the concentration of the organic cation (A2) is 1 mol / L or more and less than 4 mol / L.

[0061] The electrolytic solution for a battery according to the second aspect of the present invention specifically limits the cations (A1) and organic cations (A2) in the electrolytic solution for a battery according to the first aspect of the present invention. Preferred configurations such as the anions and cations (A) that form a redox pair in the electrolytic solution for a battery according to the second aspect of the present invention are the same as those in each configuration according to the first aspect of the present invention.

[0062] The electrolytic solution for a battery according to the first aspect of the present invention and the electrolytic solution for a battery according to the second aspect of the present invention can be used as an electrolytic solution for batteries such as redox flow batteries and thermochemical batteries. The electrolytic solution for a battery according to the first aspect of the present invention and the electrolytic solution for a battery according to the second aspect of the present invention are preferably electrolytic solutions for the positive electrode of a redox flow battery.

[0063] [Redox Flow Battery] The redox flow battery of the present invention includes the electrolytic solution for a battery of the present invention.

[0064] FIG. 1 is a schematic diagram showing an example of a redox flow battery. The redox flow battery of the present invention can adopt a known configuration. Regarding a configuration example of the redox flow battery of the present invention, FIG. 1 will be used for explanation, but it is not limited to the following configuration.

[0065] The redox flow battery 1 is used in a form called a battery cell stack in which battery cells 2 are used as the minimum unit and are stacked alone or in multiple layers, and an electrolytic solution containing an active material is circulated through the battery cells 2 to perform charge and discharge. The redox flow battery 1 mainly includes a battery cell 2 having a positive electrode cell 11 incorporating a positive electrode 10, a negative electrode cell 21 incorporating a negative electrode 20, and a separator 30 interposed between the positive electrode 10 and the negative electrode 20 to separate both cells and permeate predetermined ions. The redox flow battery 1 includes a positive electrode electrolyte tank 12 that stores a positive electrode electrolyte circulated and supplied to the positive electrode cell 11, a positive electrode forward path pipe 13 that sends the positive electrode electrolyte from the positive electrode electrolyte tank 12 to the positive electrode cell 11, and a positive electrode return path pipe 14 that returns the positive electrode electrolyte from the positive electrode cell 11 to the positive electrode electrolyte tank 12. A pump 15 for circulating the positive electrode electrolyte is disposed in the positive electrode forward path pipe 13. Similarly, the redox flow battery 1 includes a negative electrode electrolyte tank 22 that stores a negative electrode electrolyte circulated and supplied to the negative electrode cell 21, a negative electrode forward path pipe 23 that sends the negative electrode electrolyte from the negative electrode electrolyte tank 22 to the negative electrode cell 21, and a negative electrode return path pipe 24 that returns the negative electrode electrolyte from the negative electrode cell 21 to the negative electrode electrolyte tank 22. A pump 25 for circulating the negative electrode electrolyte is disposed in the negative electrode forward path pipe 23. In the redox flow battery 1 configured as described above, the positive electrode electrolyte in the positive electrode electrolyte tank 12 is sent to the positive electrode cell 11 through the positive electrode forward path pipe 13 by starting the pump 15. The positive electrode electrolyte sent to the positive electrode cell 11 is discharged upward through the inside from below the battery cell 2, returned to the positive electrode electrolyte tank 12 through the positive electrode return path pipe 14, and circulated. Similarly, the negative electrode electrolyte in the negative electrode electrolyte tank 22 is sent to the negative electrode cell 21 through the negative electrode forward path pipe 23 by starting the pump 25. The negative electrode electrolyte sent to the negative electrode cell 21 is discharged upward through the inside from below the negative electrode cell 21, returned to the negative electrode electrolyte tank 22 through the negative electrode return path pipe 24, and circulated. Thereby, charge and discharge reactions are performed in the battery cell 2 (positive electrode cell 11, negative electrode cell 21), and power can be taken out or stored.

[0066] The redox flow battery of the present invention preferably contains the electrolyte for a battery of the present invention as a positive electrode electrolyte.

[0067] The following matters are disclosed in this specification.

[0068] The present disclosure (1) is an electrolyte for a battery containing an anion serving as a redox pair, a cation (A), and water, and is an electrolyte for a battery that satisfies all of the following conditions (1) to (4). (1) The cation (A) contains only one kind of cation (A1) with a membrane resistance of 1 Ωcm or less and at least one kind of organic cation (A2) with a membrane resistance of 5 Ωcm or more; 2 (2) The pH of a 0.01 mol / L aqueous solution of the salt of the cation (A1) and chloride ions is 3 to 8; 2 (3) The pH of a 0.01 mol / L aqueous solution of the salt of the organic cation (A2) and chloride ions is 3 to 10; (4) The concentration of the cation (A1) is 1 mol / L or more and less than 5 mol / L, and the concentration of the organic cation (A2) is 1 mol / L or more and less than 4 mol / L. (5) The present disclosure (2) is the electrolyte for a battery according to the present disclosure (1), wherein the molecular weight of the organic cation (A2) is 200 or less. (6) The present disclosure (3) is the electrolyte for a battery according to the present disclosure (1) or (2), wherein the cation (A1) is one selected from the group consisting of Li ions, Na ions, K ions, and NH4 ions. (7) The present disclosure (4) is the electrolyte for a battery according to any one of the present disclosures (1) to (3), wherein the organic cation (A2) is at least one selected from the group consisting of choline cation, tetramethylammonium cation, tetraethylammonium cation, diethylmethyl-(2-methoxyethyl)ammonium cation, triethylmethylammonium cation, and 1-ethyl-3-methylimidazolium cation. (8) The present disclosure (5) is the electrolyte for a battery according to any one of the present disclosures (1) to (4), wherein the ratio {A2 / (A1 + A2)} of the molar concentration of the organic cation (A2) to the total of the molar concentration of the cation (A1) and the molar concentration of the organic cation (A2) is less than 70%.

[0069]

[0070] + + + +

[0071]

[0072]

[0073] ​​​​​​ The present disclosure (6) includes an organic cation (A21) in which the organic cation (A2) has a cyclic structure, The battery electrolyte according to any one of the present disclosures (1) to (5), wherein the ratio {A21 / (A1+A2)} of the molar concentration of the organic cation (A21) having the cyclic structure to the total of the molar concentration of the cation (A1) and the molar concentration of the organic cation (A2) is less than 55%.

[0074] The present disclosure (7) is the battery electrolyte according to any one of the present disclosures (1) to (6), wherein the anions serving as the redox pair are ferricyanide ions and ferrocyanide ions.

[0075] The present disclosure (8) is a battery electrolyte containing an anion serving as a redox pair, a cation (A), and water, wherein the cation (A) is Li + ion, Na + ion, K + ion, and NH4 + ion, and contains only one kind of cation (A1) selected from the group consisting of ions and at least one or more organic cations (A2) selected from the group consisting of choline cation, tetramethylammonium cation, tetraethylammonium cation, diethylmethyl-(2-methoxyethyl)ammonium cation, triethylmethylammonium cation, and 1-ethyl-3-methylimidazolium cation, The battery electrolyte is such that the concentration of the cation (A1) is 1 mol / L or more and less than 5 mol / L, and the concentration of the organic cation (A2) is 1 mol / L or more and less than 4 mol / L.

[0076] The present disclosure (9) is the battery electrolyte according to any one of the present disclosures (1) to (8), which is for the positive electrode of a redox flow battery.

[0077] The present disclosure (10) is a redox flow battery including the battery electrolyte according to any one of the present disclosures (1) to (9).

Examples

[0078] Next, the present invention will be specifically described by way of examples. However, the present invention is not limited to the examples as long as the gist of the present invention is not deviated from. Unless otherwise specified, "parts" means parts by weight and "%" means % by weight.

[0079] In each of the examples and comparative examples, as shown in Table 1, a cation (A1), an organic cation (A2), and a redox species (an anion serving as a redox pair) were selected to prepare an electrolyte for a battery.

[0080] [Table 1]

[0081] The substances used in each of the examples and comparative examples described in Table 1 are as follows. Cation (A1) K: Potassium cation Li: Lithium cation Na: Sodium cation Organic cation (A2) Ch: Choline cation EMIM: 1-Ethyl-3-methylimidazolium cation DEME: Diethylmethyl-(2-methoxyethyl)ammonium cation Redox species [Fe(CN)6] 3- / 4- : Ferricyanide ion and ferrocyanide ion

[0082] [Preparation of electrolyte] Among the electrolytes used in each of the examples and comparative examples, the electrolyte having an organic cation (A2) as a constituent ion was prepared by the following method. A raw material containing an organic cation (A2) as a constituent ion (such as ChCl, EMIMBr, EMIMPF6, DEMEBF4, EMIMDCA, etc.) and a raw material containing an anion serving as a redox pair (such as Na4[Fe(CN)6], K3[Fe(CN)6], K4[Fe(CN)6], etc.) were stirred at room temperature for 5 hours in an organic solvent (such as methanol, ethanol, acetonitrile, butanol, DMF, THF, ethyl acetate, etc.), whereby a reaction solution containing precipitation of by-products and a target product was obtained. Regarding the raw material containing an organic cation (A2) as a constituent ion, in order to promote the reaction with the raw material containing an anion serving as a redox pair, it was used after being converted into another salt in advance as necessary. After removing the by-product salts (such as NaCl, KBr, etc.) by filtration, the organic solvent was removed from the reaction solution by drying under reduced pressure to obtain the target product.

[0083] The raw materials used in the above production method are as follows. Raw material containing organic cation (A2) as a constituent ion ChCl: Choline chloride (manufactured by Tokyo Chemical Industry Co., Ltd., purity: >98.0%) EMIMBr: 1-Ethyl-3-methylimidazolium bromide (manufactured by Tokyo Chemical Industry Co., Ltd., purity: >98.0%) EMIMPF6: 1-Ethyl-3-methylimidazolium hexafluorophosphate (manufactured by Merck, purity: ≧97.0%) DEMEBF4: N,N-Diethyl-N-methyl-N-(2-methoxyethyl)ammonium tetrafluoroborate (manufactured by Kanto Chemical Co., Inc., for material research) EMIMDCA: 1-Ethyl-3-methylimidazolium dicyanamide (manufactured by Merck, purity: ≧98.5%) Raw material containing an anion serving as a redox pair (also used as an electrolyte as described in Table 1) Na4[Fe(CN)6]·10H2O (manufactured by Fujifilm Wako Pure Chemical Corporation, purity: 95.0+%) K3[Fe(CN)6] (manufactured by Fujifilm Wako Pure Chemical Corporation, special grade reagent) K4[Fe(CN)6]·3H2O (manufactured by Fujifilm Wako Pure Chemical Corporation, special grade reagent)

[0084] The electrolytes described in Table 1 are as follows. Ferrocyanide K4[Fe(CN)6]·3H2O (manufactured by Fujifilm Wako Pure Chemical Corporation, special grade reagent) Na4[Fe(CN)6]·10H2O (manufactured by Fujifilm Wako Pure Chemical Corporation, purity: 95.0+%) Ch4[Fe(CN)6], [EMIM]4[Fe(CN)6]: electrolytes prepared by the method described above Ferricyanide K3[Fe(CN)6] (manufactured by Fujifilm Wako Pure Chemical Corporation, special grade reagent) Ch3[Fe(CN)6], [EMIM]3[Fe(CN)6], [DEME]3[Fe(CN)6]: electrolytes prepared by the method described above Supporting salt LiCl: Lithium chloride (manufactured by Fujifilm Wako Pure Chemical Corporation, purity: 99.0+%)

[0085] [Measurement of maximum concentration (mol / kg) of redox species] For each example and comparative example, a plurality of samples were prepared with the concentrations of ferrocyanide and ferricyanide changed in increments of 0.05 mol / kg, such as 0.55, 0.60, and 0.65 mol / kg, and the solubility was examined. Specifically, each ferrocyanide and ferricyanide was weighed to a specified amount, 5 g of ion-exchanged water was added, and the mixture was stirred at 25°C for several hours. After standing at room temperature for one day, it was visually determined whether there was undissolved residue. The maximum concentration at which no undissolved residue was observed was taken as the maximum concentration (mol / kg) of the redox species. In the above test, each sample was prepared with the ratio of ferrocyanide (ferrocyanide ion) to ferricyanide (ferricyanide ion) fixed at equimolar. The maximum concentration of the redox species in Table 1 means the total concentration of ferrocyanide ion and ferricyanide ion.

[0086] For Example 5, the maximum concentration (mol / kg) of the redox species was measured under the condition that 1.5 mol / kg of LiCl was added in common to each sample with the concentrations of ferrocyanide and ferricyanide changed.

[0087] 1 mL of the sample that reached the maximum concentration in the above test was weighed three times, and the average value was determined as the density. Then, using the obtained density, the maximum concentration (mol / L) of the redox species was converted by the following formula. Maximum concentration of redox species (mol / L) = 1000 × amount of redox species (mol) / {mass of solution (g) / density (g / mL)}

[0088] Table 1 shows the results of evaluating the maximum concentration (mol / L) of the redox species according to the following criteria. ◎: 0.90 or more 〇: 0.70 or more and less than 0.90 ×: less than 0.70

[0089] For the following evaluations, measurements were carried out using the electrolyte solution that reached the maximum concentration in the above test. The concentrations of the electrolyte, cation (A1), and organic cation (A2) shown in Table 1 indicate the concentrations in the electrolyte solution where the concentration of the redox species is the maximum concentration.

[0090] [Measurement of charge-discharge density (Ah / L)] The charge-discharge density (Ah / L) was calculated by multiplying the maximum concentration (mol / L) of the redox species by 26.8. When the reaction occurring in the redox flow battery is A → A + + e - If so, Assuming that the molar concentration of the redox species A contained in the electrolyte solution is X [mol / L], the number of moles per liter is X, so the amount of electricity that can be extracted is X [mol] × 96500 [C / mol] = 96500 × X [C]. Since 1 Ah is 3600 [C], the energy density [Ah / L] of this electrolyte solution is 96500X [C / L] ÷ 3600 [C / Ah] = 26.8X [Ah / L].

[0091] [Measurement of resistance (Ω·cm 2 ) As the separator of a commercially available redox flow battery evaluation kit (manufactured by ECF Frontier Co., Ltd.: SB1200), a cation exchange membrane (Nafion TM NR211) was used, and the electrolytes of each example and comparative example were flowed on the positive electrode side and the negative electrode side at a flow rate of 0.45 mL / min., and the resistance was evaluated using an impedance measuring device (manufactured by solartron analytical: 1280C). By subtracting the value of the Blank resistance from the obtained resistance value and multiplying the value by the electrode area of the carbon felt electrode (10 mm × 50 mm × 3 mm thick), the resistance (Ω·cm 2 ) was obtained. The Blank resistance was measured in a state of internal short circuit without using a cation exchange membrane. This value was taken as the Blank resistance derived from the evaluation device. The conditions during the resistance measurement were as follows. Amplitude: 10 mV Frequency: 20000 Hz Temperature during evaluation: 25 degrees

[0092] The results of evaluating the resistance (Ω·cm 2 ) according to the following criteria are shown in Table 1. ◎: Less than 1.2 〇: 1.2 or more and less than 3.0 ×: 3.0 or more

[0093] [Measurement of reaction potential (V vs Ag / AgCl)] Cyclic voltammetry was measured in a state where an Ag / AgCl electrode (manufactured by EC Frontier: RE-T8A) was immersed as a reference electrode in the electrolyte of the evaluation system used for the measurement of the resistance described above. The current-voltage was controlled by an Electrochemical Analyzer (manufactured by BAS Inc., model 608E) and evaluated at a sweep rate of 10 mV / s . The potential (V 4- ) when the maximum current value associated with the oxidation of the redox species ([Fe(CN)6] 3- →[Fe(CN)6] ox ) was obtained, and the potential (V redIt was obtained, and the reaction potential was calculated by the following formula. Reaction potential E = (V ox + V red ) / 2

[0094] Table 1 shows the results of evaluating the reaction potential (V vs Ag / AgCl) according to the following criteria. ◎: 0.220 or more 〇: Greater than 0.190 and less than 0.220 △: 0.190 or less

[0095] [Electrolyte precipitation during charge and discharge] In the evaluation system in the measurement of the reaction potential described above, a constant current was applied to make it a fully charged state (all redox species on the positive electrode side are oxidized). Then, a constant current was applied in the direction opposite to that for making it a fully charged state to make it a fully discharged state (all redox species on the positive electrode side are reduced). After one charge-discharge cycle was completed, the circulation of the electrolytic solution to the positive electrode side and the negative electrode side was stopped, and after the positive electrode solution was allowed to stand at room temperature for 1 hour, it was visually confirmed whether a precipitate was formed from the positive electrode solution.

[0096] "None" in Table 1 means that no precipitate was visually confirmed. "Precipitation occurred" in Table 1 means that a precipitate was visually confirmed.

[0097] It was found that the electrolytic solution for a battery shown in Table 1 had higher solubility of the electrolyte, could suppress the precipitation of the electrolyte, and had a lower resistance as an electrolytic solution, compared with the electrolytic solution for a battery of the comparative example.

[0098] <Examination of the ratio of the molar concentration of cation (A1) to the molar concentration of organic cation (A2)>[ The following shows the results of examining the influence of the ratio {A2 / (A1 + A2)} of the molar concentration of organic cation (A2) to the total of the molar concentration of cation (A1) and the molar concentration of organic cation (A2) on the reaction potential of the electrolytic solution for a battery.

[0099] [Reaction potential of electrolytic solutions containing each cation] The cations shown in Table 2 and [Fe(CN)6] 3- / 4- (Ferricyanide ion and ferrocyanide ion) only as the electrolyte, the reaction potential (V vs Ag / AgCl) of the electrolyte solution was measured. The measurement of the reaction potential (V vs Ag / AgCl) was carried out by the method described above. The concentration of the cation in each electrolyte solution was 0.8 mol / kg. The ratio of ferrocyanide (ferrocyanide ion) to ferricyanide (ferricyanide ion) in each electrolyte solution was made equimolar. The results are shown in Table 2.

[0100]

Table 2

[0101] [Reaction potential of electrolyte solution containing organic cation (A21) having a cyclic structure] As the cation (A1), Li ion with a low reaction potential shown in Table 2 + ion was combined with EMIM with a low reaction potential shown in Table 2 as the organic cation (A21) having a cyclic structure to form a cation, and [Fe(CN)6] 3- / 4- (Ferricyanide ion and ferrocyanide ion) was used as the anion, and the reaction potential of the electrolyte solution was examined. The results are shown in Table 3.

[0102]

Table 3

[0103] The molar ratio (%) of {A21 / (A1 + A2)} in Table 3 means the ratio of the molar concentration of the organic cation (A21) having a cyclic structure to the total of the molar concentration of the cation (A1) and the molar concentration of the organic cation (A2).

[0104] The mixed potential (calculated) (V vs Ag / AgCl) in Table 3 is a calculated value obtained by the following formula. Mixed potential = (Li + concentration × 0.240 + EMIM concentration × 0.149) / (Li+ (Concentration + EMIM Concentration) The 0.240 in the above formula is Li + The reaction potential of the single ion (the Li reaction potential in Table 2) + is. The 0.149 in the above formula is the reaction potential of the single EMIM (the reaction potential of EMIM in Table 2).

[0105] Regarding the mixed potential (calculated) (V vs Ag / AgCl), similar to the reaction potential in Table 1, the evaluation results based on the following criteria are shown in Table 3. ◎: 0.220 or more 〇: Greater than 0.190 and less than 0.220 △: 0.190 or less

[0106] In Example 9 where the molar ratio (%) of {A2 / (A1 + A2)} was 55.1%, the mixed potential (calculated) (V vs Ag / AgCl) was slightly 0.190 or less.

[0107] [Reaction Potential of Electrolyte Containing Organic Cation (A22) without Cyclic Structure] As the cation (A1), Li with a low reaction potential shown in Table 2 + ion was combined with DEME with a low reaction potential shown in Table 2 as the organic cation (A22) without a cyclic structure to form a cation, and [Fe(CN)6] 3- / 4- (Ferricyanide ion and ferrocyanide ion) was used as the anion, and the reaction potential of the electrolyte was examined. The results are shown in Table 4.

[0108]

Table 4

[0109] The molar ratio (%) of {A22 / (A1 + A2)} in Table 4 means the ratio of the molar concentration of the organic cation (A22) without a cyclic structure to the total of the molar concentration of the cation (A1) and the molar concentration of the organic cation (A2).

[0110] The mixed potential (calculated) (V vs Ag / AgCl) in Table 4 is the calculated value obtained by the following formula. Mixed potential = (Li + concentration × 0.240 + DEME concentration × 0.182) / (Li + concentration + DEME concentration) The 0.240 in the above formula is the reaction potential of Li + in its elemental form (the reaction potential of Li + in Table 2). The 0.182 in the above formula is the reaction potential of DEME in its elemental form (the reaction potential of DEME in Table 2).

[0111] Regarding the mixed potential (calculated) (V vs Ag / AgCl), similar to the reaction potential in Table 1, the evaluation results based on the following criteria are shown in Table 4. ◎: 0.220 or more 〇: Greater than 0.190 and less than 0.220 △: 0.190 or less

[0112] In Examples 10 to 13, the evaluation results of the mixed potential (calculated) (V vs Ag / AgCl) were all ◎ or 〇.

Explanation of Symbols

[0113] 1 Redox flow battery 2 Battery cell 10 Positive electrode 11 Positive electrode cell 12 Positive electrode electrolyte tank 13 Positive electrode forward path pipe 14 Positive electrode return path pipe 15 Pump 20 Negative electrode 21 Negative electrode cell 22 Negative electrode electrolyte tank 23 Negative electrode forward path pipe 24 Negative electrode return path pipe 25 Pump 30 Diaphragm

Claims

1. A battery electrolyte solution containing an anion that forms a redox pair, a cation (A), and water, and which satisfies all of the following conditions (1) to (4): (1) The cation (A) has a membrane resistance of 1 Ω cm ２ Only one cation (A1) having a membrane resistance of 5 Ω cm ２ and at least one organic cation (A2) which is equal to or greater than the above; (2) the pH of a 0.01 mol / L aqueous solution of a salt of the cation (A1) and a chloride ion is 3 to 8; (3) the pH of a 0.01 mol / L aqueous solution of the salt of the organic cation (A2) and a chloride ion is 3 to 10; (4) The concentration of the cation (A1) is 1 mol / L or more and less than 5 mol / L, and the concentration of the organic cation (A2) is 1 mol / L or more and less than 4 mol / L.

2. 2. The battery electrolyte according to claim 1, wherein the organic cation (A2) has a molecular weight of 200 or less.

3. The cation (A1) is Li ＋ Ion, Na ＋ Ion, K ＋ ions and NH ４ ＋ 2. The battery electrolyte according to claim 1, wherein the electrolyte is one selected from the group consisting of ions.

4. The battery electrolyte according to claim 1, wherein the organic cation (A2) is at least one selected from the group consisting of a choline cation, a tetramethylammonium cation, a tetraethylammonium cation, a diethylmethyl-(2-methoxyethyl)ammonium cation, a triethylmethylammonium cation, and a 1-ethyl-3-methylimidazolium cation.

5. 2. The battery electrolyte solution according to claim 1, wherein a ratio of a molar concentration of the organic cation (A2) to a sum of a molar concentration of the cation (A1) and a molar concentration of the organic cation (A2), {A2 / (A1+A2)}, is less than 70%.

6. The organic cation (A2) includes an organic cation (A21) having a cyclic structure, The ratio {A21 / (A1 + A2)} of the molar concentration of the organic cation (A21) having a cyclic structure to the total of the molar concentration of the cation (A1) and the molar concentration of the organic cation (A2) is less than 55%. The electrolyte for a battery according to claim 1.

7. The electrolyte for a battery according to claim 1, wherein the anion serving as a redox pair is a ferricyanide ion and a ferrocyanide ion.

8. An electrolyte for a battery containing an anion serving as a redox pair, a cation (A), and water, The cation (A) is Li ＋ ion, Na ＋ ion, K ＋ ion, and NH ４ ＋ Only one kind of cation (A1) selected from the group consisting of ions and at least one kind of organic cation (A2) selected from the group consisting of choline cation, tetramethylammonium cation, tetraethylammonium cation, diethylmethyl-(2-methoxyethyl)ammonium cation, triethylmethylammonium cation, and 1-ethyl-3-methylimidazolium cation, The electrolyte for a battery, wherein the concentration of the cation (A1) is 1 mol / L or more and less than 5 mol / L, and the concentration of the organic cation (A2) is 1 mol / L or more and less than 4 mol / L.

9. The electrolyte for a battery according to any one of claims 1 to 8, which is for the positive electrode of a redox flow battery.

10. A redox flow battery including the electrolyte for a battery according to any one of claims 1 to 8.

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