Chemical method for all-solid-state batteries

Abstract

To provide a method for producing all-solid-state batteries that can shorten the time required to uniformly raise the temperature of the all-solid-state batteries before the aging process without degrading the performance of the all-solid-state batteries. [Solution] A method for forming an all-solid-state battery having an electrode laminate in which a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer are stacked, comprising a heating step of raising the temperature of the all-solid-state battery and an aging step of holding the heated all-solid-state battery, wherein the heating step of the all-solid-state battery is a method of dielectric heating of the solid electrolyte layer by applying a high-frequency alternating electric field along the stacking direction of the electrode laminate.

Description

[Technical Field]

[0001] This invention relates to a method for producing all-solid-state batteries. [Background technology]

[0002] In recent years, research and development has been conducted on secondary batteries that contribute to energy efficiency in order to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. Among secondary batteries, all-solid-state batteries, which consist of multiple electrode stacks made up of stacked positive electrodes, solid electrolytes, and negative electrodes, are considered particularly promising.

[0003] The manufacturing process for secondary batteries includes a chemical conversion step that performs an initial charge-discharge step and an aging step. The initial charge-discharge step is the process of charging and discharging the assembled secondary battery. The aging step is the process of holding a charged secondary battery at a temperature above room temperature and checking for any subsequent degradation. In the aging step, the secondary battery may be heated to 60°C and held thereafter. Methods for heating secondary batteries include placing them in a heating container such as a constant temperature bath (temperature-controlled constant temperature bath) and external heating methods that heat the secondary battery from the outside using heating means such as an infrared heater (see Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2017-22067 [Overview of the project] [Problems that the invention aims to solve]

[0005] Incidentally, one of the challenges in solid-state battery technology is improving productivity. To improve the productivity of solid-state batteries, shortening the curing time of assembled solid-state batteries is effective. To shorten the curing time, it is effective to perform the initial charge / discharge process and the aging process with multiple solid-state batteries bound together. However, when multiple solid-state batteries are bound together and heated by an external heating method before the aging process, the time required to uniformly raise the temperature inside the solid-state batteries becomes longer. It is possible to increase the heating rate of solid-state batteries by raising the external temperature, but in this case, the outer casing of the solid-state battery may become excessively hot, potentially degrading the performance of the solid-state battery.

[0006] This invention has been made in view of the above circumstances, and aims to provide a method for producing all-solid-state batteries that can shorten the time required to uniformly raise the temperature of the all-solid-state battery before the aging process without degrading the performance of the all-solid-state battery. This will ultimately contribute to energy efficiency. [Means for solving the problem]

[0007] The inventors of the present invention have found that dielectric heating of the solid electrolyte layer of an all-solid-state battery is effective in addressing the above-mentioned problems, and have completed the present invention. Accordingly, the present invention provides the following:

[0008] (1) A method for forming an all-solid-state battery having an electrode stack comprising a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, comprising a heating step of raising the temperature of the all-solid-state battery and an aging step of holding the heated all-solid-state battery, wherein the heating step of the all-solid-state battery is a method of dielectric heating of the solid electrolyte layer by applying a high-frequency alternating electric field along the stacking direction of the electrode stack.

[0009] According to the all-solid-state battery formation method of (1), the above method is used as the heating method for the all-solid-state battery in the heating step, so the all-solid-state battery can be heated from the internal solid electrolyte layer. Therefore, the time required to uniformly heat the all-solid-state battery can be shortened without degrading the performance of the all-solid-state battery. As a result, the formation time of the all-solid-state battery can be shortened, and the productivity of the all-solid-state battery is improved.

[0010] (2) The method for forming an all-solid-state battery according to (1), wherein the frequency of the high-frequency AC electric field is in the range of 1 MHz or more and 200 MHz or less.

[0011] According to the method for forming an all-solid-state battery in (2), the frequency of the high-frequency AC electric field is within the above range, so the solid electrolyte layer can be heated more reliably.

[0012] (3) A method for forming an all-solid-state battery according to (1) or (2), wherein the frequency of the high-frequency alternating electric field is set based on the relative permittivity of the solid electrolyte layer.

[0013] According to the method for forming an all-solid-state battery in (3), the frequency of the high-frequency AC electric field is set based on the relative permittivity of the solid electrolyte layer, so the solid electrolyte layer can be heated more reliably.

[0014] (4) A method for forming an all-solid-state battery according to any one of (1) to (3), wherein the heating step is performed while constraining the stacking direction of the electrode stack of the all-solid-state battery.

[0015] According to the chemical formation method for all-solid-state batteries in (4), the temperature of the all-solid-state battery can be raised more uniformly.

[0016] (5) A method for forming an all-solid-state battery according to any one of (1) to (4), wherein the all-solid-state battery has a laminate film covering the electrode stack, and in the heating step, a pair of electrodes are placed on the surface of the laminate film so as to sandwich the all-solid-state battery in the stacking direction of the electrode stack, and a high-frequency alternating electric field is applied between the pair of electrodes.

[0017] According to the method for activating a solid-state battery of (5), even when a plurality of solid-state batteries are stacked in the stacking direction of the electrode laminate, each of the solid-state batteries can be heated uniformly.

[0018] (6) The solid-state battery has a laminate film covering the electrode laminate, the positive electrode layer has a positive electrode current collector, a positive electrode tab connected to the positive electrode current collector is exposed from the laminate film, the negative electrode layer has a negative electrode current collector, and a negative electrode tab connected to the negative electrode current collector is exposed from the laminate film. In the heating step, a high-frequency alternating current electric field is applied between the positive electrode tab and the negative electrode tab. The method for activating a solid-state battery according to any one of (1) to (4).

[0019] (6) According to the method for activating a solid-state battery of (6), even when a plurality of solid-state batteries are stacked in the stacking direction of the electrode laminate, each of the solid-state batteries can be heated uniformly.

[0020] (7) The solid electrolyte layer contains a sulfide solid electrolyte. The method for activating a solid-state battery according to any one of (1) to (6).

[0021] (7) According to the method for activating a solid-state battery of (7), the solid electrolyte layer can be surely heated by applying a high-frequency alternating current electric field.

Advantages of the Invention

[0022] According to the present invention, it is possible to provide a method for activating a solid-state battery that can shorten the time for uniformly heating the solid-state battery before the aging step without deteriorating the performance of the solid-state battery.

Brief Description of the Drawings

[0023] [Figure 1] It is a perspective view showing an example of a solid-state battery that can be used in the method for activating a solid-state battery according to the present invention. [Figure 2] It is a sectional view taken along line II-II of FIG. 1. [Figure 3]This is a schematic diagram showing an example of a dielectric heating system used in the heating step of the chemical formation method for all-solid-state batteries according to the present invention. [Figure 4] This is a schematic diagram showing another example of a dielectric heating system used in the heating step of the chemical formation method for all-solid-state batteries according to the present invention. [Figure 5] This is a cross-sectional view of an evaluation sample used in a verification experiment of the chemical formation method for all-solid-state batteries according to the present invention. [Figure 6] This is a schematic diagram showing the dielectric heating system used in a verification experiment of the chemical formation method for all-solid-state batteries according to the present invention. [Modes for carrying out the invention]

[0024] The following describes a method for forming an all-solid-state battery according to one embodiment of the present invention, with reference to the drawings. In this embodiment, the all-solid-state battery is a lithium metal battery using lithium ions as the charge transfer medium.

[0025] The chemical conversion of all-solid-state batteries is performed on the all-solid-state battery immediately after assembly. First, the structure of the all-solid-state battery to which the chemical conversion method of this embodiment is applied will be described.

[0026] Figure 1 is a perspective view showing an example of an all-solid-state battery that can be used in the all-solid-state battery formation method according to the present invention. Figure 2 is a cross-sectional view taken along line II-II in Figure 1.

[0027] The all-solid-state battery 1 comprises an electrode stack 10 and an outer casing 50 that houses the electrode stack 10. A positive electrode tab 25 and a negative electrode tab 35 extend outward from the outer casing 50.

[0028] The electrode stack 10 is a stack in which a positive electrode layer 20, a negative electrode layer 30, and a solid electrolyte layer 40 positioned between the positive electrode layer 20 and the negative electrode layer 30 are stacked. Solid electrolyte layers 40 are positioned at both ends of the electrode stack 10 in the stacking direction. The electrode stack 10 is stacked in the following order: solid electrolyte layer 40, positive electrode layer 20, solid electrolyte layer 40, negative electrode layer 30, solid electrolyte layer 40, positive electrode layer 20... positive electrode layer 20, solid electrolyte layer 40, negative electrode layer 30, solid electrolyte layer 40, positive electrode layer 20, solid electrolyte layer 40.

[0029] The positive electrode layer 20 includes a positive electrode current collector 21 and a positive electrode active material layer 22 arranged on both sides of the positive electrode current collector 21.

[0030] Examples of the shape of the positive electrode current collector 21 include foil, plate, mesh, nonwoven fabric, and foam forms. Examples of materials for the positive electrode current collector 21 include aluminum, aluminum alloy, stainless steel, nickel, iron, and titanium.

[0031] The positive electrode active material layer 22 contains a positive electrode active material. The positive electrode active material may contain a lithium compound that releases lithium ions during charging and absorbs lithium ions during discharge. Examples of lithium compounds that can be used include layered active materials, spinel-type active materials, and olivine-type active materials. Specific examples of positive electrode active materials include lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), and lithium nickel manganese cobalt oxide (NMC:LiNi p Mn q Co r O2(p+q+r=1), LiNi p Al q Co r O2 (p+q+r=1), lithium manganese (LiMn2O4), Li 1+x Mn 2-x-yHetero-element substituted Li-Mn spinel represented by MO4 (x + y = 2, M is at least one selected from Al, Mg, Co, Fe, Ni, and Zn), lithium titanate (oxide containing Li and Ti), lithium metal phosphate (LiMPO4, M is at least one selected from Fe, Mn, Co, and Ni), and the like can be mentioned. The positive electrode active material layer 22 may further contain a conductive assistant, a binder, a solid electrolyte, and the like.

[0032] The positive electrode tab 25 is connected to the positive electrode current collector 21. Examples of the material of the positive electrode tab 25 include aluminum, aluminum alloy, stainless steel, nickel, iron, and titanium.

[0033] The negative electrode layer 30 has a negative electrode current collector 31 and negative electrode active material layers 32 disposed on both surface sides of the negative electrode current collector 31.

[0034] Examples of the shape of the negative electrode current collector 31 include, for example, foil shape, plate shape, mesh shape, non-woven fabric shape, foamed shape, and the like. Examples of the material of the positive electrode current collector 21 include copper, copper alloy, stainless steel, and nickel.

[0035] The negative electrode active material layer 32 may contain a negative electrode active material that can occlude lithium ions during charging and release lithium ions during discharging. As the negative electrode active material, lithium, a metal or alloy that forms a lithium alloy, a carbon material, a lithium transition metal oxide, a transition metal oxide, a metal sulfide, or a metal nitride can be used. Examples of the metal and alloy that form an alloy with lithium include Mg, Zn, Al, In, Si, Ge, Sn, Ag, Au, Pt, Pd, Pb, Sb, Bi, and alloys containing these. Examples of the carbon material include graphite, soft carbon, and hard carbon. Examples of the lithium transition metal oxide include lithium titanate (Li4Ti5O 12Examples of transition metal oxides include TiO2, Nb2O3, and WO3. When the negative electrode active material is lithium, a metal or alloy forming a lithium alloy, the negative electrode active material may be a thin film. When the negative electrode active material is a powder of a carbon material, lithium transition metal oxide, transition metal oxide, metal sulfide, metal nitride, etc., the negative electrode active material layer 32 may further contain a conductive additive, a binder, and a solid electrolyte.

[0036] The negative electrode tab 35 is connected to the negative electrode current collector 31. Examples of materials for the negative electrode tab 35 include copper, copper alloy, stainless steel, and nickel.

[0037] The solid electrolyte layer 40 contains a solid electrolyte. The solid electrolyte is not particularly limited as long as it is a dielectric material having lithium-ion conductivity. The solid electrolyte may have a dielectric constant in the range of 20 F / m to 100 F / m and a dielectric loss in the range of 0.210 to 0.728 within a frequency range of 1 MHz to 100 MHz. Examples of solid electrolytes that can be used include sulfide solid electrolytes, oxide solid electrolytes, nitride solid electrolytes, and halide solid electrolytes.

[0038] Examples of sulfide solid electrolytes include Li2S-P2S5 and Li2S-P2S5-LiI. Sulfide solid electrolytes may have an argyrodite-type crystal structure.

[0039] Examples of oxide solid electrolytes include NASICON-type oxides, garnet-type oxides, and perovskite-type oxides. Examples of NASICON-type oxides include oxides containing Li, Al, Ti, P, and O (e.g., Li 1.5 Al 0.5 Ti 1.5 (PO4)3) is an example. Examples of garnet-type oxides include oxides containing Li, La, Zr, and O (e.g., Li7La3Zr2O). 12 Examples include perovskite-type oxides containing Li, La, Ti, and O (e.g., LiLaTiO3).

[0040] A laminate film can be used as the material for the outer casing 50. As the laminate film, a three-layer laminated film can be used in which an inner resin layer, a metal layer, and an outer resin layer are laminated in this order from the inside. The outer resin layer may be, for example, a polyamide (nylon) layer or a polyethylene terephthalate (PET) layer, the metal layer may be, for example, an aluminum layer, and the inner resin layer may be, for example, a polyethylene layer or a polypropylene layer.

[0041] The method for forming an all-solid-state battery in this embodiment includes a heating step of raising the temperature of the all-solid-state battery 1 described above, and an aging step of holding the heated all-solid-state battery 1. The temperature of the all-solid-state battery 1 after heating varies depending on the structure and application of the all-solid-state battery 1, but is, for example, in the range of 40°C to 80°C.

[0042] In the solid-state battery formation method of this embodiment, an initial charge-discharge step may be performed to charge the solid-state battery 1 before the heating step. The solid-state battery 1 undergoing the heating step may have a State of Charge (SOC) in the range of 50% to 100%.

[0043] This is a schematic diagram showing an example of a dielectric heating system used in the heating step of the chemical formation method for all-solid-state batteries according to the present invention.

[0044] As shown in Figure 3, the dielectric heating system 60a includes a high-frequency generator 61, a pair of electrodes consisting of an application electrode 62 and a ground electrode 63, an electric wire 64, and a dielectric sheet 65 placed on the ground electrode 63. The electric wire 64 connects the high-frequency generator 61 to the application electrode 62 and the high-frequency generator 61 to the ground electrode 63, respectively. The battery pack 2, in which all-solid-state batteries 1 are stacked along the stacking direction of the electrode stack 10, is positioned between the application electrode 62 and the dielectric sheet 65.

[0045] The high-frequency generator 61 generates a high-frequency alternating electric field. The frequency of the high-frequency alternating electric field may be, for example, 1 kHz or higher, or within the range of 1 MHz to 200 MHz. The output power of the high-frequency alternating electric field may be within the range of 10 W to 400 W.

[0046] The application electrode 62 and the ground electrode 63 are positioned so as to sandwich the battery pack 2. The application electrode 62 and the ground electrode 63 restrain the battery pack 2 along the stacking direction of the electrode stack 10 within the all-solid-state battery 1. The application electrode 62 applies a high-frequency alternating electric field generated by the high-frequency generator 61 to the battery pack 2. The restraining pressure on the battery pack 2 is, for example, in the range of 1.0 MPa to 5.0 MPa. Copper, copper alloy, aluminum, and aluminum alloy can be used as materials for the application electrode 62 and the ground electrode 63.

[0047] The electric wire 64 only needs to be capable of electrically connecting the high-frequency generator 61 to the application electrode 62 and the high-frequency generator 61 to the ground electrode 63. The material of the electric wire 64 can be copper, copper alloy, aluminum, or aluminum alloy.

[0048] The dielectric sheet 65 prevents heat absorption by the ground electrode 63. A PTFE (polytetrafluoroethylene) sheet can be used as the dielectric sheet 65.

[0049] In the dielectric heating system 60a, the high-frequency alternating electric field generated by the high-frequency generator 61 is applied to the battery pack 2 via the application electrode 62. As a result, the high-frequency alternating electric field is applied to each of the all-solid-state batteries 1 that make up the battery pack 2. When the high-frequency alternating electric field is applied to the all-solid-state batteries 1, the solid electrolyte contained in the solid electrolyte layer 40 of the electrode stack 10 of the all-solid-state batteries 1 undergoes dielectric polarization. As a result, the molecules and atoms of the solid electrolyte vibrate in response to the change in the electric field, and as a result the solid electrolyte generates heat, causing the solid electrolyte layer 40 to act as a heat-generating element inside the all-solid-state battery 1. Since the all-solid-state batteries 1 generate heat internally, even when the battery pack 2 is made up of multiple stacked all-solid-state batteries 1, the all-solid-state batteries 1 can be heated uniformly, and the time required for heating can be shortened.

[0050] The input strength (=current × voltage) of the high-frequency AC electric field applied to the all-solid-state battery 1 is set to a range that does not damage the all-solid-state battery 1.

[0051] Figure 4 is a schematic diagram showing another example of a dielectric heating system used in the heating step of the chemical formation method for all-solid-state batteries according to the present invention.

[0052] As shown in Figure 4, the dielectric heating system 60b includes a high-frequency generator 61, an electric wire 64, and a restraining member 66. The electric wire 64 connects the positive electrode tab 25 and negative electrode tab 35 of the all-solid-state battery 1 that constitute the battery pack 2 to the high-frequency generator 61. The dielectric heating system 60b is the same as the dielectric heating system 60a described above, except that the electric wire 64 is used to connect the high-frequency generator 61 to the positive electrode tab 25 and negative electrode tab 35 of the all-solid-state battery 1 instead of the application electrode 62 and ground electrode 63, and the battery pack 2 is restrained by the restraining member 66. Therefore, the same reference numerals are used for the same components and detailed explanations are omitted.

[0053] The restraining member 66 is positioned to sandwich the battery pack 2. The restraining member 66 restrains the battery pack 2 along the stacking direction of the electrode stack 10 within the all-solid-state battery 1.

[0054] In the dielectric heating system 60b, the high-frequency alternating electric field generated by the high-frequency generator 61 is applied to the positive electrode current collector and the negative electrode current collector 31 via the positive electrode tab 25 and the negative electrode tab 35 of the all-solid-state battery 1 that constitute the battery pack 2. When a high-frequency alternating electric field is applied between the positive electrode current collector and the negative electrode current collector 31 of the all-solid-state battery 1, the solid electrolyte contained in the solid electrolyte layer 40 undergoes dielectric polarization, causing the solid electrolyte layer 40 to generate heat. Since the all-solid-state battery 1 generates heat internally, the all-solid-state battery 1 can be heated uniformly, similar to the dielectric heating system 60a, and the time required for heating can be shortened.

[0055] In the aging process, the all-solid-state battery 1, which has been heated in the heating process, is held. The aging process can be carried out, for example, using a constant-temperature bath. In the aging process, the all-solid-state battery 1 may be restrained in the stacking direction of the electrode stack.

[0056] The all-solid-state battery 1 after the aging process may be discharged, and the State of Charge (SOC) of the all-solid-state battery 1 after the aging process may be measured. The degree of degradation of the all-solid-state battery 1 can be confirmed from the ratio of the SOC of the all-solid-state battery 1 after the aging process to the SOC of the all-solid-state battery 1 before the heating process. An all-solid-state battery 1 with a high degree of degradation is judged to be a defective product.

[0057] According to the formation method for the all-solid-state battery of this embodiment, which has the above configuration, the above method is used as the method for heating the all-solid-state battery in the heating step, so that the all-solid-state battery 1 can be heated from the internal solid electrolyte layer 40. Therefore, the time required to uniformly heat the all-solid-state battery can be shortened. In addition, since the all-solid-state battery 1 can be uniformly heated without raising the external temperature excessively high, the performance of the all-solid-state battery 1 is less likely to deteriorate. By shortening the heating step time, the formation time of the all-solid-state battery 1 can be shortened, and the productivity of the all-solid-state battery 1 is improved.

[0058] In the solid-state battery formation method of this embodiment, if the frequency of the high-frequency AC electric field applied to the solid-state battery 1 in the heating step is within the above range, the solid electrolyte layer 40 can be heated more reliably. Furthermore, by setting the frequency of the high-frequency AC electric field based on the relative permittivity of the solid electrolyte layer 40, the solid electrolyte layer can be heated even more reliably.

[0059] According to the solid-state battery formation method of this embodiment, the heating step can be performed while constraining the solid-state battery 1 in the stacking direction of the electrode stack 10, thereby enabling a more uniform heating of the solid-state battery 1.

[0060] In the method for forming an all-solid-state battery according to this embodiment, when the heating step uses the dielectric heating systems 60a and 60b described above, each of the all-solid-state batteries 1 can be uniformly heated in the state of a battery pack 2 in which multiple all-solid-state batteries 1 are stacked in the stacking direction of the electrode stack.

[0061] In the method for forming an all-solid-state battery according to this embodiment, when the solid electrolyte layer 40 of the all-solid-state battery 1 contains a sulfide solid electrolyte, the solid electrolyte layer can be reliably heated by applying a high-frequency alternating electric field.

[0062] [Verification experiment] The effect of dielectric heating will be explained based on the results of verification experiments.

[0063] Figure 5 is a cross-sectional view of the evaluation sample used in the verification experiment. The evaluation sample 100 is a laminate comprising an aluminum foil 101 (100 mm × 120 mm, thickness 12 μm), a solid electrolyte layer 102 (thickness: 75 μm) arranged on both sides of the aluminum foil 101, and a positive electrode active material layer 103 (thickness: 75 μm) arranged on the opposite side of the solid electrolyte layer 102 from the aluminum foil 101 side.

[0064] Evaluation sample 100 was prepared by applying a solid electrolyte slurry to both sides of an aluminum foil 101, drying it to form a solid electrolyte layer 102, and then applying a positive electrode active material slurry to the surface of the solid electrolyte layer 102, drying it to form a positive electrode active material layer 103. The solid electrolyte slurry was prepared by mixing 97 parts by mass of argyrodite-type sulfide solid electrolyte (median diameter 3.0 μm) and 3 parts by mass of SBR (styrene-butadiene rubber) binder, and then adding the resulting mixture to a solvent and stirring. The positive electrode active material slurry was prepared by mixing 80 parts by mass of lithium nickel-cobalt-manganese composite oxide (NCM622), 17 parts by mass of argyrodite-type sulfide solid electrolyte, 2 parts by mass of carbon black, and 1 part by mass of SBR (styrene-butadiene rubber) binder, and then adding the resulting mixture to butyl butyrate and stirring.

[0065] The verification experiment used the dielectric heating system 60a shown in Figure 3. First, a PTFE sheet (1 mm thick) was placed on the ground electrode 63 as the dielectric sheet 65. Next, the evaluation sample 100 was placed on the dielectric sheet 65, and the application electrode 62 was placed on top of the evaluation sample 100. The application electrode 62 had an electrode size of 20 × 30 mm. Then, while applying pressure to the evaluation sample 100 in the stacking direction with a press load of 0.31 MPa, a high-frequency AC electric field with a frequency of 40 MHz was applied under the conditions shown in Table 1 below. The temperature of the evaluation sample 100 was measured using a thermal camera. The results are shown in Table 1. The verification experiment was conducted in an environment with a temperature of 25°C.

[0066] [Table 1]

[0067] The results in Table 1 demonstrate that it is possible to generate heat in the solid electrolyte layer by dielectric heating, and that the rate of heat generation by dielectric heating can be adjusted by the input intensity. [Explanation of symbols]

[0068] 1 All-solid-state battery 2 battery packs 10 Electrode Stack 20 Positive electrode layer 21 Positive electrode current collector 22 Cathode active material layer 25 Positive Tab 30 Negative electrode layer 31 Negative electrode current collector 32 Negative electrode active material layer 35 Negative Electrode Tabs 40 Solid electrolyte layer 50 Laminating Films 60a, 60b Dielectric Heating System 61 High-frequency generator 62 Applied electrode 63 Ground electrode 64 Electric wire 65 Dielectric Sheet 66 Restraining member 100 Laminate for thermal evaluation 101 Aluminum Foil 102 Solid electrolyte layer 103 Cathode active material layer

Claims

1. A method for forming an all-solid-state battery having an electrode laminate in which a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer are stacked, The process includes a heating step for raising the temperature of the all-solid-state battery, and an aging step for holding the heated all-solid-state battery. A method for forming an all-solid-state battery, wherein the method for heating the all-solid-state battery in the heating step is to apply a high-frequency alternating electric field along the stacking direction of the electrode stack to dielectrically heat the solid electrolyte layer.

2. The method for forming an all-solid-state battery according to claim 1, wherein the frequency of the high-frequency AC electric field is within the range of 1 MHz to 200 MHz.

3. The method for forming an all-solid-state battery according to claim 1, wherein the frequency of the high-frequency alternating electric field is set based on the relative permittivity of the solid electrolyte layer.

4. The method for forming an all-solid-state battery according to claim 1, wherein the heating step is performed while constraining the stacking direction of the electrode stack of the all-solid-state battery.

5. The all-solid-state battery has a laminate film covering the electrode stack, A method for forming an all-solid-state battery according to claim 1, comprising arranging a pair of electrodes on the surface of the laminate film such that the all-solid-state battery is sandwiched in the stacking direction of the electrode laminate, and applying a high-frequency alternating electric field between the pair of electrodes.

6. The all-solid-state battery has a laminate film covering the electrode stack, The positive electrode layer has a positive electrode current collector, and a positive electrode tab connected to the positive electrode current collector is exposed from the laminate film. The negative electrode layer has a negative electrode current collector, and a negative electrode tab connected to the negative electrode current collector is exposed from the laminate film. A method for forming an all-solid-state battery according to claim 1, wherein a high-frequency alternating electric field is applied between the positive electrode tab and the negative electrode tab.

7. The method for forming an all-solid-state battery according to claim 1, wherein the solid electrolyte layer includes a sulfide solid electrolyte.

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