Positive Electrode Active Material for Fluoride Ion Battery and Fluoride Ion Battery

Abstract

To disclose a positive electrode active material which can increase the cycle characteristics of a fluoride ion battery.SOLUTION: The positive electrode active material for a fluoride ion battery is formed of AgCuF3.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] This application discloses a positive electrode active material for a fluoride ion battery and a fluoride ion battery.

Background Art

[0002] Patent Document 1 discloses copper fluoride (CuF2) as a positive electrode active material for a fluoride ion battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The positive electrode active material for a fluoride ion battery disclosed in Patent Document 1 has room for improvement in terms of cycle characteristics.

Means for Solving the Problems

[0005] As means for solving the above problems, this application discloses the following multiple aspects. <Aspect 1> A positive electrode active material for a fluoride ion battery, which is AgCuF3. <Aspect 2> A fluoride ion battery having a positive electrode active material layer, an electrolyte layer, and a negative electrode active material layer, wherein the positive electrode active material layer contains the positive electrode active material of Aspect 1. A fluoride ion battery. <Aspect 3> The fluoride ion battery of Aspect 2, wherein the electrolyte layer contains a solid electrolyte. The fluoride ion battery of Aspect 2.

Effects of the Invention

[0006] According to the positive electrode active material for a fluoride ion battery of the present disclosure, the cycle characteristics of the fluoride ion battery can be improved.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0008] 1. Positive Electrode Active Material for Fluoride Ion Battery The positive electrode active material for a fluoride ion battery of the present disclosure is AgCuF3. That is, the positive electrode active material of the present disclosure is composed of a composite fluoride of Ag and Cu.

[0009] The positive electrode active material is considered to be defluorinated during discharge of the fluoride ion battery and fluorinated during charging. Here, a conventional positive electrode active material (for example, CuF2) has a limit in the particle size of the active material that can contribute to the charge-discharge reaction due to the rate-limiting step of fluoride ion diffusion in the active material (that is, in large particles, only the surface can contribute to the reaction). In addition, recrystallization of the active material occurs during repeated discharge and charging, and the particle size increases with each cycle. Therefore, the proportion of the active material that can contribute to charge-discharge gradually decreases, resulting in capacity degradation for each cycle. In contrast, AgCuF3 releases F -It releases and decomposes into Ag and Cu. The Ag and Cu generated by the decomposition combine with F during charging to return to AgCuF3. The AgCuF3 generated during charging has a faster diffusion of F ions than the fluoride (e.g., CuF2) generated by the conventional cathode active material. Therefore, even if the size of the cathode active material increases, it is considered that it can contribute to the charge-discharge reaction not only near the surface of the cathode active material but also inside. As a result, capacity degradation per cycle is less likely to occur. To cause such a reversible reaction accompanying charge and discharge, it is considered important to use a composite fluoride of Ag and Cu as the cathode active material rather than a simple mixture of Ag and Cu. - Together, they combine to return to AgCuF3. The AgCuF3 generated during charging has a faster diffusion of F ions than the fluoride (e.g., CuF2) generated by the conventional cathode active material. - Since the diffusion of F ions is fast, even if the size of the cathode active material becomes large, it is considered that it can contribute to the charge-discharge reaction not only near the surface of the cathode active material but also inside. As a result, capacity degradation per cycle is less likely to occur. To cause such a reversible reaction accompanying charge and discharge, it is considered important to use a composite fluoride of Ag and Cu as the cathode active material rather than a simple mixture of Ag and Cu.

[0010] The shape of the cathode active material may be any shape that can function as the cathode active material of the fluoride ion battery. The cathode active material may be, for example, particulate. The average particle diameter (D50) of the cathode active material particles may be, for example, 1 nm or more and 500 μm or less, 10 nm or more and 100 μm or less, or 20 nm or more and 50 μm or less. Note that the average particle diameter (D50) referred to in the present application is the particle diameter (median diameter) at the integrated value of 50% in the volume-based particle size distribution determined by the laser diffraction / scattering method.

[0011] 2. Cathode Composite Material for Fluoride Ion Battery The cathode composite material for the fluoride ion battery of the present disclosure contains AgCuF3 as the cathode active material. The cathode composite material may contain a cathode active material other than AgCuF3 together with AgCuF3. Further, the cathode composite material may contain an electrolyte. Further, the cathode composite material may contain a conductive material. Further, the cathode composite material may contain a binder. In one embodiment, the cathode composite material for the fluoride ion battery may contain at least AgCuF3 as the cathode active material and an electrolyte. In one embodiment, the cathode composite material for the fluoride ion battery may contain at least AgCuF3 as the cathode active material, an electrolyte, and a conductive material. In one embodiment, the cathode composite material for the fluoride ion battery may contain at least AgCuF3 as the cathode active material, an electrolyte, a conductive material, and a binder.

[0012] 2.1 Positive electrode active material The content of the positive electrode active material in the positive electrode composite material may be, for example, 20% by mass or more and 100% by mass or less, 30% by mass or more and 100% by mass or less, or 40% by mass or more and 100% by mass or less. The positive electrode active material contained in the positive electrode composite material may be only AgCuF3, or may be a combination of AgCuF3 and a positive electrode active material other than AgCuF3. As the positive electrode active material other than AgCuF3, for example, those known as positive electrode active materials for fluoride ion batteries such as copper fluoride can be adopted. The proportion of AgCuF3 in the total (100% by mass) of the positive electrode active materials contained in the positive electrode composite material may be, for example, 30% by mass or more and 100% by mass or less, 40% by mass or more and 100% by mass or less, 50% by mass or more and 100% by mass or less, 60% by mass or more and 100% by mass or less, 70% by mass or more and 100% by mass or less, 80% by mass or more and 100% by mass or less, 90% by mass or more and 100% by mass or less, 95% by mass or more and 100% by mass or less, 99% by mass or more and 100% by mass or less, or 100% by mass.

[0013] 2.2 Electrolyte The positive electrode composite material may contain an electrolyte. The electrolyte may be a solid electrolyte or a liquid electrolyte (electrolyte solution). In particular, when the positive electrode composite material contains a solid electrolyte, high performance is easily ensured. The content of the solid electrolyte in the positive electrode composite material may be, for example, 0% by mass or more and 80% by mass or less, 0% by mass or more and 70% by mass or less, or 0% by mass or more and 60% by mass or less. The electrolyte may be only one type, or may be a combination of two or more types.

[0014] The solid electrolyte may be, for example, an inorganic solid electrolyte containing a metal element and a fluorine element. The inorganic solid electrolyte may contain only one type of metal element, or may contain two or more types of metal elements. The inorganic solid electrolyte may be, for example, at least one selected from fluorides of lanthanoid elements such as La and Ce; fluorides of alkali elements such as Li, Na, K, Rb, and Cs; fluorides of alkaline earth elements such as Ca, Sr, and Ba, etc. Specifically, fluorides of La and Ba (for example, La 0.9 Ba0.1 F 2.9 ) fluorides of La and Sr (e.g., La 0.95 Sr 0.05 F 2.95 ), fluorides of Ca and Ba (e.g., Ca 0.5 Ba 0.5 F2), fluorides of Pb and Sn, etc., and at least one selected therefrom may be used. In one embodiment, the solid electrolyte may contain at least La, Sr, and F. In one embodiment, the solid electrolyte may contain at least Ca, Ba, and F. In one embodiment, the solid electrolyte may contain at least Pb, Sn, and F. The fluorine element in the solid electrolyte can function as a carrier fluoride ion (F - ). The shape of the solid electrolyte is not particularly limited. The solid electrolyte may be, for example, in the form of particles.

[0015] The liquid electrolyte contains, for example, a solvent and a salt dissolved in the solvent. The solvent may be, for example, an organic solvent. The organic solvent may be any one that can dissolve the salt. The organic solvent is, for example, R such as triethylene glycol dimethyl ether (G3), tetraethylene glycol dimethyl ether (G4), etc. 1 -O(CH2CH2O) n -R 2 (R 1 and R 2Each is independently an alkyl group having 4 or fewer carbon atoms or a fluoroalkyl group having 4 or fewer carbon atoms, and n is in the range of 2 to 10) represented by glyme; cyclic carbonates such as ethylene carbonate (EC), fluoroethylene carbonate (FEC), difluoroethylene carbonate (DFEC), propylene carbonate (PC), butylene carbonate (BC); chain carbonates such as dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), etc., and at least one selected therefrom may be used. Further, the organic solvent may be an ionic liquid. The salt dissolved in the above solvent may be, for example, a fluoride salt. The fluoride salt may be at least one selected from, for example, inorganic fluoride salts, organic fluoride salts, ionic liquids, etc. The inorganic fluoride salt may be, for example, XF (X is at least one selected from Li, Na, K, Rb, and Cs). The organic fluoride salt may have an ammonium cation such as a tetramethylammonium cation and a fluorine-containing anion. The liquid electrolyte may be, for example, the above solvent and the above salt dissolved at a concentration of 0.1 mol or more and 40 mol or less, or 1 mol or more and 10 mol or less per 1 L of the solvent.

[0016] 2.3 Conductive Material The positive electrode composite material may contain a conductive material. The conductive material may be any material having electron conductivity. The conductive material may be only one type or a combination of two or more types. The conductive material may be, for example, made of a carbon material. The carbon material as the conductive material may be at least one selected from, for example, carbon blacks such as acetylene black, furnace black, thermal black, graphene, fullerene, carbon nanotubes, etc. The shape of the conductive material is not particularly limited. The conductive material may be, for example, particulate or fibrous.

[0017] 2.4 Binder The positive electrode composite material may contain a binder. The binder may be chemically and electrically stable in a fluoride ion battery. The binder may be only one type or a combination of two or more types. The binder may be, for example, a fluorine-based binder such as a polyvinylidene fluoride (PVDF)-based binder or a polytetrafluoroethylene (PTFE)-based binder, or a rubber-based binder such as styrene butadiene rubber (SBR).

[0018] 2.5 Supplementary The positive electrode composite material may contain various additives other than the above components. The positive electrode composite material can be obtained by mixing the above components. The mixing method is not particularly limited, and may be, for example, dry or wet mixing by a ball mill, or slurry kneading, etc. Also, before mixing, pre-grinding treatment of the positive electrode active material may be performed.

[0019] 3. Fluoride Ion Battery FIG. 1 schematically shows the configuration of a fluoride ion battery 100 according to an embodiment. The fluoride ion battery 100 has a positive electrode active material layer 10, an electrolyte layer 20, and a negative electrode active material layer 30. The positive electrode active material layer 10 contains the positive electrode active material (i.e., AgCuF3) of the present disclosure.

[0020] 3.1 Positive Electrode Active Material Layer The positive electrode active material layer 10 may be composed of, for example, the above positive electrode composite material. The shape of the positive electrode active material layer 10 is not particularly limited, and may be, for example, a sheet-like shape having a substantially flat surface. The thickness of the positive electrode active material layer 10 is not particularly limited, and may be an appropriate thickness according to the configuration of the fluoride ion battery 100, etc. The positive electrode active material layer 10 may have a thickness of, for example, 100 nm or more and 1 mm or less.

[0021] 3.2 Electrolyte Layer The electrolyte layer 20 is disposed between the positive electrode active material layer 10 and the negative electrode active material layer 30. The electrolyte layer 20 contains at least an electrolyte. In one embodiment, the electrolyte layer 20 may contain at least a solid electrolyte. In one embodiment, the electrolyte layer 20 may contain a solid electrolyte and a binder. In one embodiment, the electrolyte layer 20 may contain a liquid electrolyte and a separator for holding the liquid electrolyte.

[0022] The electrolyte contained in the electrolyte layer 20 may be a solid electrolyte or a liquid electrolyte. In particular, when the electrolyte layer 20 contains a solid electrolyte, high performance is easily ensured. The electrolyte may be only one kind or a combination of two or more kinds. The solid electrolyte and the liquid electrolyte may be appropriately selected from those exemplified as those that can be contained in the above-described positive electrode composite material. The electrolyte that can be contained in the positive electrode composite material and the electrolyte contained in the electrolyte layer 20 may be of the same kind or different kinds.

[0023] The binder that can be contained in the electrolyte layer 20 may be only one kind or a combination of two or more kinds. The binder may be appropriately selected from those exemplified as those that can be contained in the above-described positive electrode composite material. The binder that can be contained in the positive electrode composite material and the binder that can be contained in the electrolyte layer 20 may be of the same kind or different kinds.

[0024] When the electrolyte layer 20 has a separator for holding a liquid electrolyte, any of those known as separators for fluoride ion batteries can be adopted.

[0025] The electrolyte layer 20 may be, for example, partly converted into the negative electrode active material layer 30 by charging. Specifically, during charging of the fluoride ion battery 100, a defluorination reaction of a metal fluoride as a solid electrolyte may occur at the interface between the electrolyte layer 20 and the negative electrode current collector 50, and a metal layer (for example, a Pb layer) as the negative electrode active material layer 30 may be formed at the interface.

[0026] The shape of the electrolyte layer 20 is not particularly limited, and for example, it may be in the form of a sheet having a substantially flat surface. The thickness of the electrolyte layer 20 is not particularly limited, and may be an appropriate thickness according to the configuration of the fluoride ion battery 100 or the like. For example, the electrolyte layer 20 may have a thickness of 100 nm or more and 1 mm or less.

[0027] 3.3 Anode active material layer The anode active material layer 30 contains at least an anode active material. The anode active material layer 30 may contain at least one of an electrolyte, a conductive material, and a binder together with the anode active material. The content of each component in the anode active material layer 30 may be the same as that in the prior art.

[0028] The anode active material contained in the anode active material layer 30 may be, for example, at least one selected from a simple metal, an alloy, a metal oxide, a metal fluoride, a carbon material, and a polymer material. The metal element constituting the anode active material may be, for example, at least one selected from La, Ca, Al, Eu, Li, Si, Ge, Sn, In, V, Cd, Cr, Fe, Zn, Ga, Ti, Nb, Mn, Yb, Zr, Sm, Ce, Mg, and Pb. The carbon material constituting the anode active material may be, for example, at least one selected from graphite, coke, and carbon nanotubes. The polymer material constituting the anode active material may be at least one selected from polyaniline, polypyrrole, polyacetylene, and polythiophene.

[0029] The electrolyte contained in the anode active material layer 30 may be a solid electrolyte or a liquid electrolyte. In particular, when the anode active material layer 30 contains a solid electrolyte, high performance is easily ensured. The electrolyte may be only one kind or a combination of two or more kinds. The solid electrolyte or the liquid electrolyte may be appropriately selected from those exemplified as those that can be contained in the above-described cathode composite material. The electrolyte that can be contained in the cathode composite material and the electrolyte that can be contained in the anode active material layer 30 may be of the same type or different types.

[0030] The conductive material that can be included in the negative electrode active material layer 30 may be only one type or a combination of two or more types. The conductive material may be appropriately selected from those exemplified as being able to be included in the above-described positive electrode composite material. The conductive material that can be included in the positive electrode composite material and the conductive material that can be included in the negative electrode active material layer 30 may be of the same type or different types.

[0031] The binder that can be included in the negative electrode active material layer 30 may be only one type or a combination of two or more types. The binder may be appropriately selected from those exemplified as being able to be included in the above-described positive electrode composite material. The binder that can be included in the positive electrode composite material and the binder that can be included in the negative electrode active material layer 30 may be of the same type or different types.

[0032] The shape of the negative electrode active material layer 30 is not particularly limited, and for example, it may be in the form of a sheet having a substantially flat surface. The thickness of the negative electrode active material layer 30 is not particularly limited, and may be an appropriate thickness according to the configuration of the fluoride ion battery 100 etc. The negative electrode active material layer 30 may have a thickness of, for example, 100 nm or more and 1 mm or less.

[0033] 3.4 Other configurations The fluoride ion battery 100 may have a positive electrode current collector 40 electrically connected to the positive electrode active material layer 10 and a negative electrode current collector 50 electrically connected to the negative electrode active material layer 30. The positive electrode current collector 40 and the negative electrode current collector 50 may be the same as known ones, and for example, various current collectors such as foil-shaped, mesh-shaped, and porous-shaped ones can be adopted.

[0034] The fluoride ion battery 100 may be an all-solid-state battery that does not contain a liquid component or a battery that contains a liquid component. Also, the fluoride ion battery 100 may be a primary battery or a secondary battery. Further, the shape of the fluoride ion battery 100 may be, for example, coin-shaped, laminate-shaped, cylindrical, or rectangular. The fluoride ion battery 100 can be easily manufactured through processes such as forming the above-described respective layers by dry or wet methods.

[0035] 4. Vehicle with a fluoride ion battery As described above, according to the technology of the present disclosure, the cycle characteristics of a fluoride ion battery can be improved. Such a fluoride ion battery can be suitably used, for example, in at least one vehicle selected from a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a battery electric vehicle (BEV). That is, the technology of the present disclosure is a vehicle having a fluoride ion battery, wherein the fluoride ion battery has a positive electrode active material layer, an electrolyte layer, and a negative electrode active material layer, and the positive electrode active material layer contains AgCuF3 as a positive electrode active material, and also has a side as such. Details of the fluoride ion battery are as described above.

Example

[0036] Hereinafter, the technology of the present disclosure will be described in more detail while showing examples, but the technology of the present disclosure is not limited to the following examples.

[0037] 1. Example 1 1.1 Preparation of positive electrode active material AgF and CuF2 were weighed so that the molar ratio was 1:1, and then mixed and reacted by mechanical milling using a ball mill apparatus (Planetary Ball Mill Premium Line PL-7 manufactured by Fritsch) to obtain a positive electrode active material composed of AgCuF3. The mechanical milling was performed at a rotation speed of 400 rpm for 1 hour in a dry argon atmosphere. Fig. 2 shows the results of X-ray diffraction measurement of the positive electrode active material according to Example 1. The X-ray diffraction measurement was performed by the focusing method using a fully automatic multi-purpose X-ray diffractometer SmartLab manufactured by Rigaku Corporation and irradiating with CuKα rays. As shown in Fig. 2, the positive electrode active material according to Example 1 contained the AgCuF3 phase as the main phase.

[0038] 1.2 Preparation of solid electrolyte LaF3 and SrF2 were weighed so that the molar ratio was 0.95:0.05, mixed, and fired at 800 °C for 10 hours in a dry argon atmosphere to obtain La 0.95 Sr0.05 F 2.95 Crystals composed of were prepared. The obtained crystals were pulverized using a ball mill apparatus (PL-7) for 3 hours at a rotational speed of 300 rpm in a dry argon atmosphere to obtain a powdery solid electrolyte composed of La 0.95 Sr 0.05 F 2.95 .

[0039] 1.3 Preparation of the positive electrode composite material The above positive electrode active material, the above solid electrolyte, and acetylene black as a conductive material were mixed by mechanical milling using a ball mill apparatus (PL-7) to obtain a powdery positive electrode composite material. The mechanical milling was carried out at a rotational speed of 200 rpm for 3 hours in a dry argon atmosphere. The composition of the positive electrode composite material was, by mass ratio, positive electrode active material: solid electrolyte: conductive material = 35:59:5.

[0040] 1.4 Preparation of the fluoride ion battery As the negative electrode active material layer, a 220 mg Pb metal plate was prepared. Further, on the Pb metal plate, a compacted powder layer composed of 50 mg of a mixture of PbF2 powder and acetylene black powder was formed as a buffer layer. PbF2 in the above buffer layer functions as an auxiliary negative electrode active material during the charging of the fluoride ion battery and is expected to compensate for the irreversible capacity generated by the discharge and charge of the Pb metal plate. Incidentally, the acetylene black in the mixture was 5% by mass based on the whole mixture.

[0041] The above La 0.95 Sr 0.05 F 2.95 150 mg of the powder of the solid electrolyte composed of was compacted to obtain a molded body A as the electrolyte layer.

[0042] 15 mg of the above positive electrode composite material was compacted to obtain a molded body B as the positive electrode active material layer.

[0043] An aluminum foil as a negative electrode current collector, a negative electrode active material layer, a buffer layer, a molded body A (electrolyte layer), a molded body B (positive electrode active material layer), and a platinum foil as a positive electrode current collector were laminated in this order to fabricate an all-solid-state fluoride ion battery. The diameter (diameter of the electrode surface) of the all-solid-state fluoride ion battery was φ11.28 mm. The fabricated all-solid-state fluoride ion battery was placed in a cylindrical container made of ceramics with an inner diameter of 11.28 mm and fixed by sandwiching it from both sides of the negative electrode current collector and the positive electrode current collector with stainless steel cylinders having a diameter of 11.28 mm.

[0044] 2. Comparative Example 1 A powdery positive electrode composite material and an all-solid-state fluoride ion battery were obtained in the same manner as in Example 1, except that CuF2 was used instead of AgCuF3 as the positive electrode active material.

[0045] 3. Evaluation of Fluoride Ion Battery For each all-solid-state fluoride ion battery, while evacuating in a sealed container, discharging and charging were repeated 10 times at a test temperature of 200 °C and a current density of 0.05 mA / cm 2 . The discharge cut-off voltage and the charge cut-off voltage were -0.3 V and 1.5 V, respectively. For the charge-discharge test, an electrochemical measurement system (manufactured by BioLogic, VMP-300 high-performance electrochemical measurement system) was used.

[0046] Figures 3 and 4 show the results of the charge-discharge test. Figure 3 shows the results for Example 1, and Figure 4 shows the results for Comparative Example 1. Also, Figure 5 shows the results of plotting the discharge capacity of each battery for each cycle. In Figures 3 to 5, the values of the charge capacity and the discharge capacity of each battery were normalized per weight (15 mg) of the positive electrode composite material.

[0047] As shown in Figures 3 to 5, Example 1 using AgCuF3 as the positive electrode active material showed suppression of capacity degradation per cycle compared to Comparative Example 1 using CuF2, that is, it showed high cycle characteristics.

[0048] In order to confirm the actions and effects of the positive electrode active material, X-ray diffraction measurements were performed on the positive electrode active material layer (positive electrode composite material) of the fluoride ion battery of Example 1 after discharge and after charging, respectively, to confirm changes in the crystal structure of the positive electrode active material. The results are shown in FIG. 6. Here, the X-ray diffraction measurement was performed by the focusing method of irradiating CuKα1 rays with a Johansson monochromator attached to an X-ray diffractometer (SmartLab) in order to improve the peak separation ability.

[0049] As shown in FIG. 6, in the positive electrode active material layer containing AgCuF3, the formation of Ag and Cu simple substances was confirmed after discharge. On the other hand, it was confirmed that AgCuF3 was regenerated after charging.

[0050] The positive electrode active material of the fluoride ion battery may coarsen (such as grain aggregation and grain growth) during repeated charge and discharge. CuF2 of Comparative Example 1 has a limit in the particle size of the active material that can contribute to the charge and discharge reaction due to the rate-determining step of fluoride ion diffusion in the active material (that is, in large particles, only the surface can contribute to the reaction). Therefore, as the active material coarsens, the proportion of the active material that can contribute to charge and discharge gradually decreases, resulting in capacity degradation per cycle. In contrast, AgCuF3 is considered to have faster diffusion of F - ions than CuF2, and even if the positive electrode active material coarsens, it is considered that it can contribute sufficiently to the charge and discharge reaction not only near the surface of the positive electrode active material but also inside. As a result, it is presumed that in Example 1, capacity degradation per cycle was suppressed.

[0051] As described above, it was found that when AgCuF3 is used as the positive electrode active material of the fluoride ion battery, the cycle characteristics of the fluoride ion battery are improved compared to the case where CuF2 is used.

[0052] In addition, in the above example, the case of producing a positive electrode active material composed of AgCuF3 by mechanical milling was exemplified, but the positive electrode active material composed of AgCuF3 can also be produced by other methods (for example, firing method).

[0053] In addition, in the above embodiments, the case where a solid electrolyte and a conductive material are used together with the positive electrode active material in the positive electrode composite material was exemplified. However, the constituent components of the positive electrode composite material are not limited thereto. The positive electrode composite material only needs to contain at least a positive electrode active material, and may optionally contain other components.

[0054] In addition, in the above embodiments, a all-solid-state battery was exemplified as a fluoride ion battery. However, the form of the fluoride ion battery is not limited thereto. It is considered that an effect of improving cycle characteristics can be obtained by using AgCuF3 as a positive electrode active material even in a fluoride ion battery containing various liquids such as a liquid electrolyte.

Description of Reference Numerals

[0055] 10 Positive electrode active material layer 20 Electrolyte layer 30 Negative electrode active material layer 40 Positive electrode current collector 50 Negative electrode current collector 100 Fluoride ion battery

Claims

1. AgCuF ３ which is a positive electrode active material for a fluoride ion battery.

2. A fluoride ion battery having a positive electrode active material layer, an electrolyte layer, and a negative electrode active material layer, wherein the positive electrode active material layer contains the positive electrode active material according to Claim 1, a fluoride ion battery.

3. wherein the electrolyte layer contains a solid electrolyte, the fluoride ion battery according to Claim 2.

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