Test methods and all-solid-state batteries

Abstract

This invention provides a test method and an all-solid-state battery that can easily evaluate the basic characteristics of an all-solid-state battery. [Solution] In an all-solid-state battery, a counter electrode layer is sandwiched between a first electrode layer containing an electrode active material having a two-phase coexistence reaction and a second electrode layer containing an electrode active material having a two-phase coexistence reaction, a first solid electrolyte layer is provided between the first electrode layer and the counter electrode layer, a second solid electrolyte layer is provided between the second electrode layer and the counter electrode layer, and a third solid electrolyte layer is provided on the side of the first electrode layer opposite to the first solid electrolyte layer, an electrode to be evaluated is provided on the third solid electrolyte layer, the charge rate between the first electrode layer and the second electrode layer and the counter electrode layer is adjusted to the plateau region of the two-phase coexistence reaction, and the potential behavior between the first electrode layer and the electrode to be evaluated is measured.

Description

[Technical Field]

[0001] This invention relates to a test method and an all-solid-state battery. [Background technology]

[0002] In recent years, lithium-ion secondary batteries have been widely used as power sources for portable electronic devices, wearable devices, and IoT devices due to their high energy density. These lithium-ion secondary batteries use an electrolyte solution containing a flammable organic solvent as the medium for moving ions. In batteries using such flammable electrolytes, the risks of electrolyte leakage, smoke emission, and fire have been pointed out. As a means of eliminating these risks and ensuring inherent safety, development is underway on all-solid-state batteries, which use a flame-retardant solid electrolyte as an alternative to the flammable organic electrolyte and in which all components are solid.

[0003] In secondary battery devices, the balance of characteristics between the positive electrode, electrolyte, and negative electrode is crucial, and there is a need to develop methods for independently evaluating each characteristic within the battery. In liquid-based lithium-ion secondary batteries, various evaluations have been performed by introducing metal wires (Ag, Li, Li-In, etc.) between the positive and negative electrodes. In all-solid-state batteries, attempts have also been made to introduce reference electrodes using various methods, particularly in relatively flexible sulfide-based all-solid-state batteries. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-62523 [Overview of the project] [Problems that the invention aims to solve]

[0005] In oxide-based all-solid-state batteries, as an attempt to introduce a reference electrode, a configuration is used in which a cell using an active material having a two-phase coexistence reaction is connected in parallel to the evaluation cell via a solid electrolyte, making it possible to introduce a reference electrode into oxide-based all-solid-state batteries that undergo batch sintering (see, for example, Patent Document 1). With the development of this technology, it is possible to independently evaluate the characteristics of the positive and negative electrodes during low-rate charge and discharge, for example, at 0.2C or less.

[0006] However, in the technology described in Patent Document 1, the distance between the evaluation electrode and the reference electrode is relatively large. Therefore, while it can track low-rate charge / discharge operations of, for example, 0.2C or less, it is difficult to handle high-rate operations or measurements requiring high responsiveness, such as AC impedance measurements.

[0007] Another evaluation method for oxide-based all-solid-state batteries is the electrolyte-supported battery. In this electrolyte-supported battery, a sintered solid electrolyte single sheet is used as a support, with an evaluation electrode layer on top and a metallic Li layer or Li-In alloy layer placed below via a polymer separator. In this configuration, due to the low ionic conductivity of many oxide-based solid electrolytes, evaluation under high-temperature conditions is necessary for the battery to function.

[0008] This invention has been made in view of the above problems, and aims to provide a test method and an all-solid-state battery that can easily evaluate the basic characteristics of an all-solid-state battery. [Means for solving the problem]

[0009] The present invention relates to a test method for an all-solid-state battery in which a counter electrode layer is sandwiched between a first electrode layer containing an electrode active material having a two-phase coexistence reaction and a second electrode layer containing an electrode active material having a two-phase coexistence reaction, a first solid electrolyte layer is provided between the first electrode layer and the counter electrode layer, a second solid electrolyte layer is provided between the second electrode layer and the counter electrode layer, and a third solid electrolyte layer is provided on the side of the first electrode layer opposite to the first solid electrolyte layer, wherein an electrode to be evaluated is provided on the third solid electrolyte layer, the charge rate between the first electrode layer and the second electrode layer and the counter electrode layer is adjusted to the plateau region of the two-phase coexistence reaction, and the potential behavior between the first electrode layer and the electrode to be evaluated is measured.

[0010] In the above test method, the electrode active material contained in the first electrode layer and the second electrode layer may contain at least one of LiCoPO4, LiFePO4, LiCoO2, and LiMn2O4.

[0011] In the above test method, the electrode active material contained in the first electrode layer and the second electrode layer is Li4Ti5O 12 , TiO2, LiTiPO5, LiTi2(PO4)3, Li 1+x Al x Ti 2-x (PO4)3 may include at least one of the following:

[0012] In the above test method, the first electrode layer and the second electrode layer may be short-circuited, and a charge-discharge evaluation may be performed using the first electrode layer and the second electrode layer as reference electrodes, and the potential difference between the electrode under evaluation and the first electrode layer and the second electrode layer may be recorded.

[0013] In the above test method, the first electrolyte layer, the second electrolyte layer, and the third electrolyte layer may have a thickness of 1 μm or more and 50 μm or less.

[0014] The all-solid-state battery according to the present invention includes a first electrode layer containing an electrode active material having a two-phase coexistence reaction, a second electrode layer containing an electrode active material having a two-phase coexistence reaction, a counter electrode layer sandwiched between the first electrode layer and the second electrode layer, a first solid electrolyte layer provided between the first electrode layer and the counter electrode layer, a second solid electrolyte layer provided between the second electrode layer and the counter electrode layer, and a third solid electrolyte layer provided on the side of the first electrode layer opposite to the first solid electrolyte layer.

Effects of the Invention

[0015] According to the present invention, it is possible to provide a test method capable of simply evaluating the basic characteristics of an all-solid-state battery and an all-solid-state battery.

Brief Description of the Drawings

[0016] [Figure 1] It is a diagram illustrating a stacked structure of a reference electrode battery according to an embodiment. [Figure 2] (a) is a diagram illustrating a charging curve of a positive electrode reference electrode, and (b) is a diagram illustrating a discharging curve of the positive electrode reference electrode 40. [Figure 3] (a) is a diagram illustrating a charging curve of a negative electrode reference electrode, and (b) is a diagram illustrating a discharging curve of the negative electrode reference electrode. [Figure 4] It is a diagram for explaining a test using a reference electrode battery. [Figure 5] It is a diagram illustrating an electrolyte-supported battery. [Figure 6] It is a flowchart showing an example of the procedure of the test method. [Figure 7] It is a diagram illustrating the charge and discharge behavior of an evaluation target electrode.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments will be described while referring to the drawings.

[0018] (Embodiment) Figure 1 illustrates the stacked structure of a reference electrode battery 100 according to an embodiment. As illustrated in Figure 1, the reference electrode battery 100 has a structure in which a counter electrode layer 30 is sandwiched between a first electrode layer 10 and a second electrode layer 20. A first solid electrolyte layer 40a is provided between the first electrode layer 10 and the counter electrode layer 30. A second solid electrolyte layer 40b is provided between the second electrode layer 20 and the counter electrode layer 30. A third solid electrolyte layer 40c is provided on the side of the first electrode layer 10 opposite to the first solid electrolyte layer 40a. A fourth solid electrolyte layer 40d is provided on the side of the second electrode layer 20 opposite to the second solid electrolyte layer 40b. Each layer of the reference electrode battery 100 is a sintered body obtained by sintering powder material.

[0019] The first electrode layer 10 and the second electrode layer 20 contain an electrode active material having a two-phase coexistence reaction. A two-phase coexistence reaction is a reaction that proceeds in the coexistence of two phases: a crystalline phase in the charged state and a crystalline phase in the discharged state. Due to the two-phase coexistence reaction, a potential flat region (plateau region) is generated during charging and discharging.

[0020] When the first electrode layer 10 and the second electrode layer 20 function as positive electrode reference electrodes, the first electrode layer 10 and the second electrode layer 20 contain a positive electrode active material having a two-phase coexistence reaction. Examples of positive electrode active materials having a two-phase coexistence reaction include LiCoPO4, LiFePO4, LiCoO2, and LiMn2O4. Figure 2(a) illustrates the charging curves of the first electrode layer 10 and the second electrode layer 20 when they contain a positive electrode active material having a two-phase coexistence reaction. Figure 2(b) illustrates the discharge curves of the first electrode layer 10 and the second electrode layer 20 when they contain a positive electrode active material having a two-phase coexistence reaction. As illustrated in Figures 2(a) and 2(b), a plateau region is observed where the potential hardly changes even when the State of Charge (SOC) changes.

[0021] When the first electrode layer 10 and the second electrode layer 20 function as negative electrodes, the first electrode layer 10 and the second electrode layer 20 contain a negative electrode active material having a two-phase coexistence reaction. For example, Li4Ti5O 12 , TiO2, LiTiPO5, LiTi2(PO4)3, Li 1+x Al x Ti 2-x (PO4)3 and the like can be used. Figure 3(a) illustrates the charging curves of the first electrode layer 10 and the second electrode layer 20 when the first electrode layer 10 and the second electrode layer 20 contain a negative electrode active material having a two-phase coexistence reaction. Figure 3(b) illustrates the discharge curves of the first electrode layer 10 and the second electrode layer 20 when the first electrode layer 10 and the second electrode layer 20 contain a negative electrode active material having a two-phase coexistence reaction. As illustrated in Figures 3(a) and 3(b), a plateau region is created in which the potential hardly changes even when the SOC changes.

[0022] The counter electrode layer 30 functions as a counter electrode with respect to the first electrode layer 10 and the second electrode layer 20. When the first electrode layer 10 and the second electrode layer 20 function as positive electrodes, the counter electrode layer 30 functions as a negative electrode. When the first electrode layer 10 and the second electrode layer 20 function as negative electrodes, the counter electrode layer 30 functions as a positive electrode.

[0023] When the counter electrode layer 30 functions as the positive electrode, the counter electrode layer 30 contains a positive electrode active material. In this case, for example, the counter electrode layer 30 contains a material having an olivine-type crystal structure as the electrode active material. Examples of such electrode active materials include phosphates containing a transition metal and lithium. The olivine-type crystal structure is the crystal structure found in natural olivine and can be identified by X-ray diffraction. Typical examples of electrode active materials having an olivine-type crystal structure include LiCoPO4 containing Co. Phosphates in which the transition metal Co is replaced in this chemical formula can also be used. Here, the ratio of Li and PO4 can vary depending on the valency. It is preferable to use Co, Mn, Fe, Ni, etc. as the transition metal.

[0024] When the counter electrode layer 30 functions as a negative electrode, the counter electrode layer 30 contains a negative electrode active material. In this case, for example, the counter electrode layer 30 contains compounds such as titanium oxide, lithium titanium composite oxide, lithium titanium composite phosphate, carbon, and lithium vanadium phosphate as the negative electrode active material.

[0025] In addition to the electrode active material, the counter electrode layer 30 may contain a solid electrolyte having ion conductivity, a conductive material (conductive aid), and the like. As the conductive aid, a carbon material or the like may be included. As the conductive aid, a metal may be included. Examples of the metal of the conductive aid include Pd, Ni, Cu, Fe, and alloys containing these. The solid electrolyte contained in the counter electrode layer 30 can be the same as the main component solid electrolyte of the first solid electrolyte layer 40a, the second solid electrolyte layer 40b, the third solid electrolyte layer 40c, and the fourth solid electrolyte layer 40d, for example.

[0026] The first solid electrolyte layer 40a, the second solid electrolyte layer 40b, the third solid electrolyte layer 40c, and the fourth solid electrolyte layer 40d are mainly composed of an oxide-based solid electrolyte having ion conductivity. The oxide-based solid electrolyte has, for example, a NASICON-type crystal structure. The oxide-based solid electrolyte is, for example, an oxide-based solid electrolyte having lithium ion conductivity. The oxide-based solid electrolyte is, for example, a phosphate-based solid electrolyte. The phosphate-based solid electrolyte having a NASICON-type crystal structure has high conductivity and the property of being stable in the atmosphere. The phosphate-based solid electrolyte is, for example, a phosphate containing lithium. The phosphate is not particularly limited, and examples thereof include a composite lithium phosphate salt with Ti (for example, LiTi2(PO4)3). Alternatively, Ti can be partially or entirely replaced with a tetravalent transition metal such as Ge, Sn, Hf, or Zr. Also, in order to increase the Li content, it may be partially replaced with a trivalent transition metal such as Al, Ga, In, Y, or La. More specifically, for example, Li 1+x Al x Ge 2-x (PO4)3, and Li 1+x Alx Zr 2-x (PO4)3, Li 1+x Al x Ti 2-x Examples include (PO4)3.

[0027] The thicknesses of the first solid electrolyte layer 40a, the second solid electrolyte layer 40b, the third solid electrolyte layer 40c, and the fourth solid electrolyte layer 40d are, for example, 1 μm or more and 50 μm or less.

[0028] Figure 4 is a diagram illustrating a test using the reference electrode battery 100. First, the electrode 50 to be evaluated is formed on the side of the third solid electrolyte layer 40c opposite to the first electrode layer 10. Depending on the evaluation purpose, the electrode 50 to be evaluated may be made of fine particles, thin films, thin composite materials, etc. A gold (Au) electrode may be formed on the electrode 50 to be evaluated by sputtering or other methods. The electrode 50 to be evaluated may also be formed on the side of the fourth solid electrolyte layer 40d opposite to the second electrode layer 20. Below, as an example, the case in which the electrode 50 to be evaluated is formed on the third solid electrolyte layer 40c will be described.

[0029] Since the first electrode layer 10 and the electrode under evaluation 50 are stacked with a third solid electrolyte layer 40c in between, ion movement is possible between the first electrode layer 10 and the electrode under evaluation 50. On the other hand, since the third solid electrolyte layer 40c is an insulator, electron conduction between the first electrode layer 10 and the electrode under evaluation 50 is insulated.

[0030] By using this structure, the electrochemical behavior of the electrode 50 under evaluation can be tested by charging the first electrode layer 10 and the second electrode layer 20. Since the first electrode layer 10 and the second electrode layer 20 use electrode active materials having a two-phase coexistence reaction, a plateau region is generated within a predetermined SOC range, and this plateau region can be treated as a reference potential exhibiting a stable counter electrode potential.

[0031] The following describes the test method for the electrode 50 to be evaluated. First, we will describe the case where both the first electrode layer 10 and the second electrode layer 20 function as positive electrodes, and the electrode 50 to be evaluated contains a negative electrode active material.

[0032] First, a charging process is performed between the first electrode layer 10 and the second electrode layer 20 and the counter electrode layer 30 so that the state of charge (SOC) of the first electrode layer 10 and the second electrode layer 20 enters a plateau region.

[0033] Subsequently, the first electrode layer 10 and the second electrode layer 20 are used as reference electrodes, and the potential difference between the electrode 50 under evaluation and the first electrode layer 10 and the second electrode layer 20 is recorded as the negative electrode potential. Since the potentials of the first electrode layer 10 and the second electrode layer 20 are approximately constant, a charge-discharge curve of the electrode 50 under evaluation can be obtained.

[0034] During AC impedance evaluation, a charging process is performed between the first electrode layer 10 and the counter electrode layer 30 so that the SOC of the first electrode layer 10 enters a plateau region.

[0035] When evaluating AC impedance, the counter electrode layer 30 is adjusted in advance so that it enters a plateau region, and then the evaluation is performed between the first electrode layer 10 and the electrode 50 to be evaluated.

[0036] Next, we will describe the case where both the first electrode layer 10 and the second electrode layer 20 function as negative electrodes, and the electrode 50 under evaluation contains a positive electrode active material.

[0037] First, a charging process is performed between the first electrode layer 10 and the second electrode layer 20 and the counter electrode layer 30 so that the state of charge (SOC) of the first electrode layer 10 and the second electrode layer 20 enters a plateau region.

[0038] Subsequently, the first electrode layer 10 and the second electrode layer 20 are used as reference electrodes, and the potential difference between the electrode 50 under evaluation and the first electrode layer 10 and the second electrode layer 20 is recorded as the positive electrode potential. Since the potentials of the first electrode layer 10 and the second electrode layer 20 are approximately constant, a charge-discharge curve of the electrode 50 under evaluation can be obtained.

[0039] During AC impedance evaluation, a charging process is performed between the first electrode layer 10 and the counter electrode layer 30 so that the SOC of the first electrode layer 10 enters a plateau region.

[0040] When evaluating AC impedance, the counter electrode layer 30 is adjusted in advance so that it enters a plateau region, and then the evaluation is performed between the first electrode layer 10 and the electrode 50 to be evaluated.

[0041] As described above, according to this embodiment, the SOC between the first electrode layer 10 and the second electrode layer 20 and the counter electrode layer 30 is adjusted to the plateau region of the two-phase coexistence reaction, and by conducting charge-discharge tests between the first electrode layer 10 and the second electrode layer 20 and the electrode 50 to be evaluated, the electrochemical behavior of the electrode 50 to be evaluated can be tested individually. Furthermore, since the third solid electrolyte layer 40c is interposed in the thickness direction between the first electrode layer 10 and the electrode 50 to be evaluated, the distance between the first electrode layer 10 and the electrode 50 to be evaluated is shortened compared to the configuration disclosed in Patent Document 1. As a result, the behavior of the electrode 50 to be evaluated can be tested even during high-speed charge-discharge and AC impedance evaluation.

[0042] Furthermore, according to this embodiment, since the entire reference electrode battery 100 can be used as a support material, each layer can be made thinner. For example, as described above, thin films with a thickness of 1 μm to 50 μm can be used as the first solid electrolyte layer 40a, the second solid electrolyte layer 40b, and the third solid electrolyte layer 40c. In this case, it is not necessary to evaluate at high temperatures, and the basic characteristics of the all-solid-state battery can be easily evaluated under practical conditions.

[0043] Here, for comparison, we will describe evaluation using an electrolyte-supported battery. Figure 5 is an example of an electrolyte-supported battery 200. For example, as illustrated in Figure 5, the electrolyte-supported battery 200 uses a solid electrolyte sheet 201 as a support material. Below the solid electrolyte sheet 201, metal electrodes 203 made of metallic Li or metallic Li-In alloy are placed via a polymer separator 202, and the electrode to be evaluated 204 is placed on top of the solid electrolyte sheet 201. In such a configuration, since only the solid electrolyte sheet 201 is used as a support material, the solid electrolyte sheet 201 needs to be a thick plate of several hundred μm or more. In this case, evaluation at high temperatures is required, making evaluation under practical conditions difficult. Therefore, as described above, according to this embodiment, the basic characteristics of an all-solid-state battery can be easily evaluated under practical conditions.

[0044] Figure 6 is a flowchart illustrating an example of the test procedure. First, a charging process is performed between the first electrode layer 10 and the second electrode layer 20 and the counter electrode layer 30 so that the SOC of the first electrode layer 10 and the second electrode layer 20 enters a plateau region (step S1).

[0045] Next, the potential behavior of the electrode 50 to be evaluated is measured using the first electrode layer 10 as a reference electrode (step S2). For example, the charge-discharge curve is measured or the AC impedance is evaluated.

[0046] Next, we will describe the manufacturing method of the all-solid-state battery 100 for evaluation. First, a slurry is prepared by dispersing the solid electrolyte powder for the solid electrolyte layer in a mixed solvent such as ethanol and toluene, and thoroughly mixing it with an organic binder. This slurry is spread onto a surface-released PET film using a doctor blade, and multiple green sheets can be obtained by heating and drying.

[0047] A laminate is obtained by sequentially stacking a green sheet printed with the unfired material of the second electrode layer 20, a green sheet printed with the unfired material of the counter electrode layer 30, a green sheet printed with the unfired material of the first electrode layer 10, and a green sheet without the unfired material of the electrodes.

[0048] Next, the resulting laminate is fired. The firing conditions are either an oxidizing or non-oxidizing atmosphere, and the maximum temperature can be, for example, 400°C to 1000°C or 500°C to 900°C, without any particular limitations. To sufficiently remove the binder before reaching the maximum temperature, a step may be included in which the laminate is held at a temperature lower than the maximum temperature in an oxidizing atmosphere. To reduce process costs, it is desirable to fire at the lowest possible temperature. After firing, a re-oxidation treatment may be performed. Through the above steps, a reference electrode battery 100 is manufactured. [Examples]

[0049] A test all-solid-state battery was fabricated according to the following embodiment, and its characteristics were investigated.

[0050] (Examples) As the electrode active material for the first electrode layer 10 and the second electrode layer 20, LATP:Li 1+x Al x Ti 2-x (PO4)3 was used. LAGP:Li was used in the first solid electrolyte layer 40a, the second solid electrolyte layer 40b, the third solid electrolyte layer 40c, and the fourth solid electrolyte layer 40d. 1+x Al x Ge 2-x (PO4)3 was used. LCP:LiCoPO4 was used as the electrode active material for the counter electrode layer 30.

[0051] LAGP was dispersed in a mixed solvent of ethanol and toluene, and a slurry was prepared by thoroughly mixing it with an organic binder. This slurry was then spread onto a surface-released PET film using a doctor blade, and a green sheet was obtained by heat drying.

[0052] A laminate was obtained by sequentially stacking a green sheet printed with pre-sintering material containing LATP, a green sheet printed with pre-sintering material containing LCP, a green sheet printed with pre-sintering material containing LATP, and a green sheet without any pre-sintering material printed on it. Subsequently, the layers were compressed and degreased, and then fired to obtain a sintered body.

[0053] Subsequently, an LCP electrode layer was formed on the fourth solid electrolyte layer 40d, degreased and fired, and then an Au electrode was formed by sputtering to create the electrode 50 to be evaluated. Then, external terminals that can be individually connected to the first electrode layer 10, the second electrode layer 20, the counter electrode layer 30, and the electrode 50 to be evaluated were formed. A predetermined charging process was performed between the first electrode layer 10 and the second electrode layer 20 and the counter electrode layer 30 to adjust the SOC of the first electrode layer 10 and the second electrode layer 20 to 20%. A charge / discharge measuring instrument was connected between the first electrode layer 10 and the second electrode layer 20 and the electrode 50 to be evaluated, and charging and discharging were performed on the electrode 50 to be evaluated. The charge / discharge behavior of the electrode 50 to be evaluated as shown in Figure 7 was confirmed.

[0054] Although embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of Symbols]

[0055] 10 First electrode layer 20 Second electrode layer 30. Opposite Pole Layer 40a 1st solid electrolyte layer 40b Second solid electrolyte layer 40c 3rd solid electrolyte layer 40d 4th solid electrolyte layer 50 electrodes to be evaluated 100 reference pole battery

Claims

1. In an all-solid-state battery, a counter electrode layer is sandwiched between a first electrode layer containing an electrode active material having a two-phase coexistence reaction and a second electrode layer containing an electrode active material having a two-phase coexistence reaction, a first solid electrolyte layer is provided between the first electrode layer and the counter electrode layer, a second solid electrolyte layer is provided between the second electrode layer and the counter electrode layer, and a third solid electrolyte layer is provided on the side of the first electrode layer opposite to the first solid electrolyte layer, the electrode to be evaluated is provided on the third solid electrolyte layer, A test method comprising adjusting the charge level between the first electrode layer, the second electrode layer, and the counter electrode layer to the plateau region of the two-phase coexistence reaction, and measuring the potential behavior between the first electrode layer and the electrode to be evaluated.

2. The electrode active material contained in the first electrode layer and the second electrode layer is LiCoPO ４ LiFePO ４ LiCoO ２ LiMn ２ O ４ The test method according to claim 1, comprising at least one of the following.

3. The electrode active materials included in the first electrode layer and the second electrode layer are Li ４ Ti ５ O １２ , TiO ２ , LiTiPO ５ , LiTi ２ (PO ４ ) ３ , Li １＋ｘ Al ｘ Ti ２－ｘ (PO ４ ) ３ The test method according to claim 1, comprising at least any one of them.

4. The test method according to claim 1, comprising short-circuiting the first electrode layer and the second electrode layer, performing a charge-discharge evaluation using the first electrode layer and the second electrode layer as reference electrodes, and recording the potential difference between the electrode to be evaluated and the first electrode layer and the second electrode layer.

5. The test method according to claim 1, wherein the first electrolyte layer, the second electrolyte layer, and the third electrolyte layer have a thickness of 1 μm or more and 50 μm or less.

6. A first electrode layer containing an electrode active material having a two-phase coexistence reaction, A second electrode layer containing an electrode active material having a two-phase coexistence reaction, A counter electrode layer sandwiched between the first electrode layer and the second electrode layer, A first solid electrolyte layer is provided between the first electrode layer and the counter electrode layer, A second solid electrolyte layer is provided between the second electrode layer and the counter electrode layer, A solid-state battery comprising: a third solid electrolyte layer provided on the side of the first electrode layer opposite to the first solid electrolyte layer.

Images