All-solid-state battery production method

Abstract

The purpose of the present invention is to newly provide an all-solid-state battery production method. This all-solid-state battery production method 1b includes: (1) a step in which a positive electrode 17 is formed from a mixture that includes a positive electrode active material 27 and a first solid electrolyte 26; (2) a step in which a solid electrolyte section 15 is formed from a second solid electrolyte 25; (3) a step in which plasma processing is applied to a surface on the solid electrolyte section 15 side of the formed positive electrolyte 17; and (4) a step in which the positive electrode 17, the solid electrolyte section 15, and a negative electrode 14 are stacked in that order and pressed.

Description

Manufacturing method for all-solid-state batteries

[0001] This invention relates to a method for manufacturing an all-solid-state battery.

[0002] Patent Document 1 discloses (A) composite particles comprising positive electrode active material particles and a coating film, wherein the coating film 24 covers at least a portion of the surface of the positive electrode active material particles 23, and the coating film comprises composite particles comprising fluorine, phosphorus, glass network forming elements, etc.; (B) a positive electrode 13 comprising the composite particles and a sulfide solid electrolyte; and (C) an all-solid-state battery 1a comprising the positive electrode, etc. (see Figure 2).

[0003] Publication number JP 2024-11259

[0004] The present invention aims to provide a new method for manufacturing all-solid-state batteries.

[0005] Conventionally, in the manufacturing of all-solid-state batteries as described in Patent Document 1, a coating film 24 is coated onto the positive electrode active material 23 (powder) (see Patent Document 1, Figure 2), which results in poor uniformity and may cause localized interfacial reactions between the positive electrode active material and the sulfide solid electrolyte, potentially degrading the cycle characteristics of the all-solid-state battery. Conventionally, in the manufacturing of all-solid-state batteries, the entire positive electrode active material is coated, and the coating film is present to a similar extent as the positive electrode active material, potentially reducing the energy density.

[0006] The present inventors, in order to solve the problems remaining in such conventional technologies, conducted extensive research and found that in an all-solid-state battery comprising a positive electrode containing a positive electrode active material and a first solid electrolyte, a solid electrolyte portion consisting of a second solid electrolyte, and a negative electrode, it is possible to manufacture an all-solid-state battery that provides good cycle characteristics by performing plasma treatment at the interface between the positive electrode and the solid electrolyte portion, preferably on the solid electrolyte portion side of the positive electrode.

[0007] The present invention encompasses the following methods for manufacturing all-solid-state batteries.

[0008] Item 1. A method for manufacturing an all-solid-state battery, comprising: (1) a step of molding a positive electrode with a mixture containing a positive electrode active material and a first solid electrolyte; (2) a step of molding a solid electrolyte portion with a second solid electrolyte; (3) a step of applying plasma treatment to the surface of the molded positive electrode on the side of the solid electrolyte portion; and (4) a step of stacking the positive electrode, the solid electrolyte portion, and the negative electrode in this order and pressing them.

[0009] Item 2. The method for manufacturing an all-solid-state battery according to Item 1, wherein the positive electrode active material and the first solid electrolyte are oxides, and the second solid electrolyte is a sulfide.

[0010] Item 3. The method for manufacturing an all-solid-state battery according to Item 1, wherein steps (1) and (2) are carried out in a first environment with a dew point of -60°C or lower, step (3) is carried out in a second environment with a pressure of approximately 100 Pa or lower, and step (5) includes a step of transporting a sample between the first environment and the second environment, and step (5) includes storing the sample in a vacuum-sealed vessel.

[0011] Item 4. A method for manufacturing an all-solid-state battery according to Item 1, wherein the positive electrode active material comprises lithium (Li), nickel (Ni), manganese (Mn), cobalt (Co), and oxygen (O), the first solid electrolyte comprises lithium (Li), aluminum (Al), titanium (Ti), phosphorus (P), and oxygen (O), and the second solid electrolyte comprises lithium (Li), phosphorus (P), sulfur (S), and chlorine (Cl).

[0012] Item 5. The positive electrode active material is LiNi 0.5 Mn 0.2 Co 0.3 The first solid electrolyte is O2, and the first solid electrolyte is Li 1.3 Al 0.3 Ti 1.7 The method for manufacturing an all-solid-state battery according to item 1, wherein the second solid electrolyte is (PO4)3 and Li6PS5Cl.

[0013] The all-solid-state battery manufactured by the manufacturing method of the present invention has plasma treatment applied to the interface between the positive electrode and the solid electrolyte, resulting in good cycle characteristics.

[0014] This invention provides a novel method for manufacturing all-solid-state batteries.

[0015] Figure 1 is a diagram illustrating a cross-sectional view of an all-solid-state battery 1b having a plasma ashing section 16 (plasma processing section) manufactured by the manufacturing method of the present invention, in comparison with a conventional all-solid-state battery 1a. Figure 2 is a diagram illustrating the presence of a plasma ashing section 16 (plasma processing section) at the interface between the positive electrode 17 and the solid electrolyte section 15 in the all-solid-state battery 1b manufactured by the manufacturing method of the present invention, in comparison with a conventional all-solid-state battery 1a. Figure 3 is a diagram illustrating a vacuum processing apparatus used in the manufacturing method of the all-solid-state battery 1b manufactured by the manufacturing method of the present invention. Figure 4 is a diagram illustrating a vessel 44 used in the manufacturing method of the all-solid-state battery 1b manufactured by the manufacturing method of the present invention. Figure 5 is a diagram illustrating the cycle characteristics of an all-solid-state battery 1b having a plasma ashing section 16 (plasma processing section), in comparison with an example of a conventional all-solid-state battery 1a without plasma processing.

[0016] The present invention will be described in detail below.

[0017] The embodiments illustrating the present invention are intended to provide a better understanding of the invention's intent and, unless otherwise specified, do not limit the scope of the invention.

[0018] In this specification, "contains" and "include" are concepts that encompass all of the following: "comprise," "consist essentially of," and "consist of."

[0019] In this specification, when a numerical range is indicated as "A to B", the numerical range means "greater than or equal to A and less than or equal to B".

[0020] [1] Method for manufacturing an all-solid-state battery The method for manufacturing an all-solid-state battery of the present invention is shown below.

[0021] Figure 1 is a diagram illustrating a comparison between a cross-sectional view of a conventional all-solid-state battery 1a and a cross-sectional view of an all-solid-state battery 1b manufactured by the manufacturing method of the present invention. The conventional all-solid-state battery 1a has a negative electrode 11, a solid electrolyte section 12, and a positive electrode 13, as shown on the left of Figure 1. The all-solid-state battery 1b manufactured by the manufacturing method of the present invention has a negative electrode 14, a solid electrolyte section 15, a plasma ashing section 16 (plasma processing section), and a positive electrode 17, as shown on the right of Figure 1.

[0022] Figure 2 illustrates, in comparison with a conventional all-solid-state battery 1a, that the all-solid-state battery 1b manufactured by the manufacturing method of the present invention has a plasma ashing section 16 (plasma processing section) at the interface between the positive electrode 17 and the solid electrolyte section 15. Note that the negative electrodes 11 and 14 are omitted from Figure 2.

[0023] As shown on the left of Figure 2, the solid electrolyte portion 12 of the conventional all-solid-state battery 1a is formed by a second solid electrolyte 21. The positive electrode 13 of the conventional all-solid-state battery 1a is formed by a first solid electrolyte 22, a positive electrode active material 23, and a coating film 24 that coats the positive electrode active material 23. The second solid electrolyte 21 is a sulfide, and the first solid electrolyte 22 and the positive electrode active material 23 are oxides.

[0024] As shown on the right in Figure 2, the solid electrolyte portion 15 of the all-solid-state battery 1b manufactured by the manufacturing method of the present invention is formed of a second solid electrolyte 25. The positive electrode 17 of the all-solid-state battery 1b is formed of a first solid electrolyte 26 and a positive electrode active material 27. The all-solid-state battery 1b has a plasma ashing portion 16 (plasma processing portion) at the interface between the solid electrolyte portion 15 and the positive electrode 17. The plasma ashing portion 16 (plasma processing portion) is formed by performing plasma treatment on the positive electrode 17, as will be described later. The second solid electrolyte 25 is a sulfide, and the first solid electrolyte 26 and the positive electrode active material 27 are oxides.

[0025] The manufacturing method of the all-solid-state battery 1b includes: (1) a step of molding the positive electrode 17 with a mixture containing the positive electrode active material 27 and the first solid electrolyte 26; (2) a step of molding the solid electrolyte part 15 with the second solid electrolyte 25; (3) a step of subjecting the surface of the molded positive electrode 17 on the side of the solid electrolyte part 15 to plasma treatment; and (4) a step of laminating and pressing the positive electrode 17, the solid electrolyte part 15, and the negative electrode 14 in this order.

[0026] Hereinafter, the above steps (1) to (4) will be described in order. (1) Step of molding the positive electrode 17 with a mixture containing the positive electrode active material 27 and the first solid electrolyte 26 The manufacturing method of the all-solid-state battery 1b includes a step of molding the positive electrode 17 with a mixture containing the positive electrode active material 27 and the first solid electrolyte 26. The step of molding the positive electrode preferably involves compression molding of a mixture containing the positive electrode active material and the first solid electrolyte.

[0027] Step (1) is preferably carried out in a first environment with a dew point of -60°C or lower in order to suppress deterioration of characteristics due to adsorption of moisture or the like.

[0028] The positive electrode active material 27 is an oxide, for example, an oxide containing the lithium element (Li), nickel element (Ni), manganese element (Mn), cobalt element (Co), and oxygen element (O).

[0029] The positive electrode active material particles are preferably LiCoO2, LiNiO2, LiMnO2, LiMn2O4, Li(NiCoMn)O2, Li(NiCoAl)O2, LiFePO4, etc. Li(NiCoMn)O2 is, for example, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, LiNi 0.5 Co 0.2 Mn 0.3 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2, etc. The positive electrode active material 27 is more preferably LiNi 0.5 Mn 0.2 Co 0.3 O2.

[0030] The first solid electrolyte 26 preferably uses an oxide that does not contain sulfur in that it can suppress the diffusion of sulfur into the oxide-based positive electrode active material 27. The first solid electrolyte 26 is, for example, an oxide containing a lithium element (Li), an aluminum element (Al), a titanium element (Ti), a phosphorus element (P), and an oxygen element (O), such as Li 1.3 Al 0.3 Ti 1.7 (PO4)3.

[0031] The positive electrode 17 may further contain a conductive material. The conductive material can form an electron conduction path within the positive electrode 17. Preferably, acetylene black, carbon black, vapor-grown carbon fiber (VGCF), carbon nanotube (CNT), graphene flakes, or the like is used as the conductive material.

[0032] The positive electrode 17 may further contain a binder. Preferably, polyvinylidene fluoride (PVdF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), styrene-butadiene rubber (SBR), polytetrafluoroethylene (PTFE), or the like is used as the binder.

[0033] (2) A method for manufacturing the all-solid-state battery 1b including a step of molding the solid electrolyte part 15 with the second solid electrolyte 25. The method for manufacturing the all-solid-state battery 1b includes a step of molding the solid electrolyte part 15 with the second solid electrolyte 25. The step of molding the solid electrolyte part 15 preferably involves sintering or compacting only the second solid electrolyte 25 or a mixture containing the second solid electrolyte 25.

[0034] Step (2) is preferably carried out in a first environment with a dew point of -60°C or lower in order to suppress characteristic deterioration due to moisture adsorption or the like.

[0035] The second solid electrolyte 25 is relatively soft and can have a small porosity and low resistance after molding. Preferably, a sulfide is used. More preferably, the second solid electrolyte 25 uses a sulfide containing a lithium element (Li), a phosphorus element (P), a sulfur element (S), and a chlorine element (Cl), and even more preferably, Li6PS5Cl is used.

[0036] (3) A step of applying plasma treatment to the surface of the positive electrode 17 on the solid electrolyte portion 15 side after molding The manufacturing method of the all-solid-state battery 1b includes (3) a step of applying plasma treatment to the surface of the positive electrode 17 on the solid electrolyte portion 15 side after molding (forming a plasma ashing portion 16).

[0037] Figure 3 illustrates a vacuum processing apparatus 4 used in the manufacturing method of the all-solid-state battery 1b produced by the manufacturing method of the present invention. Figure 4 illustrates a vessel used in the manufacturing method of the all-solid-state battery 1b produced by the manufacturing method of the present invention.

[0038] As shown in Figure 3, the vacuum processing apparatus 4 includes a load lock chamber 4a and a plasma processing chamber 4b.

[0039] In the vacuum processing apparatus 4, a gate valve is provided to separate the load lock chamber 4a and the plasma processing chamber 4b. With the gate valve open, the sample transport mechanism 47 can transport the sample holder 44c (see Figure 4), on which the object to be processed is placed, between the load lock chamber 4a and the plasma processing chamber 4b shown in Figure 3.

[0040] An inert gas (Ar gas, nitrogen, etc.) is introduced from the gas piping (gas inlet) 41 to purge the inside of the load lock chamber 4a, thereby minimizing the inflow of outside air into the load lock chamber 4a through the opening of the door.

[0041] The operator introduces the vessel 44 into the load lock chamber 4a through the opening of the door and places it on the fixing part of the vessel 44. The vessel 44 maintains a vacuum even after the atmosphere is removed. Vacuum piping 42 is connected to the load lock chamber 4a, making it possible to evacuate the load lock chamber 4a.

[0042] Plasma processing chamber 4b is equipped with a processing chamber 46 and performs film deposition and plasma processing while maintaining a vacuum environment for the sample. Plasma processing chamber 4b is equipped with an antenna 48 for generating inductively coupled plasma within the plasma processing chamber. Vacuum piping 43 is connected to processing chamber 46, making it possible to evacuate processing chamber 46.

[0043] The vessel 44 applied to the vacuum processing apparatus 4 is a portable vacuum transport container capable of housing an object to be processed while maintaining a vacuum. As shown in Figure 4, the vessel 44 consists of a vessel plate 44a and a vessel cover 44b, and houses the object to be processed together with a sample holder 44c on which the object to be processed is placed in the internal space partitioned by the vessel plate 44a and the vessel cover 44b.

[0044] The vessel 44 enables the transport of the object to be processed while it is held in a vacuum between the vacuum processing apparatus 4 and other devices. For this purpose, the load lock chamber 4a is configured to receive the vessel 44 at the vessel fixing section, detach the vessel cover 44b of the vessel 44 from the vessel plate 44a, and remove or store the object to be processed together with the sample holder 44c.

[0045] The upper surface of the ceiling portion of the vessel cover 44b is provided with two screw fastening portions 44d for the opening and closing drive units. The screw fastening portions 44d of the vessel cover 44b engage with the screw portions of the load lock chamber 4a. The upper surface of the vessel plate 44a is provided with a dovetail groove 44e for an O-ring that encircles the outer edge of the vessel plate 44a.

[0046] Step (3) is preferably carried out in a second environment of about 100 Pa or less, in terms of ease of plasma ignition and maintenance. In particular, when generating inductively coupled plasma, as in the plasma processing chamber 4b in Figure 3, the above pressure range is preferred.

[0047] In Figure 3, an example is shown in which the antenna 48 is located outside the plasma processing chamber 4b. However, when inductively coupled plasma is generated inside the plasma processing chamber 4b, the antenna may be located inside the plasma processing chamber 4b. When the antenna is located inside, the power efficiency for plasma generation is high, so the power supplied to the antenna can be reduced. On the other hand, when the antenna is located outside, the power efficiency for plasma generation is relatively low, but because the antenna is outside, it is difficult for impurities to enter the plasma processing chamber, and contamination of the positive electrode surface can be suppressed.

[0048] The surface of the molded positive electrode 17 on the solid electrolyte portion 15 side is the interface between the molded positive electrode 17 and the solid electrolyte portion 15.

[0049] Plasma treatment can preferably be performed on the workpiece in a vacuum. In the plasma treatment chamber 4b, the workpiece can be treated in a vacuum, and plasma treatment, sputtering, plasma CVD (Chemical Vapor Deposition) treatment, plasma etching treatment, plasma ashing treatment, etc. Plasma treatment is more preferably plasma ashing treatment. Plasma ashing treatment is a treatment in which oxygen plasma is used to react (combine) with organic matter (carbon), vaporize and decompose (ash) as CO2 (remove by gasification of carbon dioxide).

[0050] Plasma treatments such as ashing, which do not involve film formation, exhibit effects other than suppression of sulfur atom diffusion, such as dehydration and removal of organic matter. Even without sulfur, plasma treatments such as ashing, which do not involve film formation, result in the formation of a good bond between the positive electrode and the solid electrolyte layer through dehydration and removal of organic matter, and also suppress excess interfacial reactions with moisture, resulting in good cycle characteristics.

[0051] Alternatively, different plasma treatments may be combined.

[0052] (4) A step of stacking the positive electrode 17, the solid electrolyte portion 15, and the negative electrode 17 in this order and pressing them together. The manufacturing method of the all-solid-state battery 1b includes (4) a step of stacking the positive electrode 17, the solid electrolyte portion 15, and the negative electrode (Li / In, etc.) 14 in this order and pressing them together.

[0053] (5) A step of transporting a sample between a first environment and a second environment. The method for manufacturing an all-solid-state battery 1b preferably includes (5) a step of transporting a sample between a first environment and a second environment.

[0054] Step (5) preferably includes storing the sample in a vacuum-sealed vessel 44.

[0055] (6) A step of providing an oxide coating film at the interface between the molded positive electrode 17 and the solid electrolyte portion 15. The method for manufacturing an all-solid-state battery 1b may further include (6) a step of providing an oxide coating film at the interface between the molded positive electrode and the solid electrolyte portion.

[0056] The oxide coating film may be provided at the interface between the positive electrode 17 and the solid electrolyte portion 15, either on the surface of the positive electrode 17 facing the solid electrolyte portion 15, or on the surface of the solid electrolyte portion 15 facing the positive electrode 17. Preferably, the oxide coating film coats the positive electrode active material 27 forming the positive electrode 17 and the first solid electrolyte 26 at the interface between the positive electrode 17 and the solid electrolyte portion 15. Preferably, the oxide coating film is provided at the interface between the positive electrode 17 and the solid electrolyte portion 15, on the surface of the positive electrode 17 facing the solid electrolyte portion 15.

[0057] The all-solid-state battery 1b manufactured by the manufacturing method of the present invention can, in this manner, further suppress the diffusion of sulfur contained in the second solid electrolyte 25 into the positive electrode active material 27, even when the film deposition amount is on the order of nanometers on the surface of the positive electrode 17 which has irregularities on the order of micrometers.

[0058] The oxide coating film can be fabricated, for example, by sputtering or plasma CVD. In this case, it becomes possible to continuously fabricate the oxide coating film within the plasma processing chamber 4b where the plasma processing is performed, thereby forming a high-quality oxide coating film / plasma ashing section 16 (plasma processing section) interface, and reducing mass production costs by shortening the cycle time.

[0059] The oxide coating film preferably has a thickness of 7.5 nm to 45 nm.

[0060] The oxide coating film is preferably formed from components containing lithium (Li), aluminum (Al), titanium (Ti), phosphorus (P), and oxygen (O), and more preferably Li 1.3 Al 0.3 Ti 1.7 It is formed from (PO4)3.

[0061] When the above step (6) is included in the manufacturing method, the all-solid-state battery 1b exhibits good cycle characteristics because it has an oxide coating film at the interface between the positive electrode 17 and the solid electrolyte portion 15.

[0062] [2] All-solid-state battery The all-solid-state battery 1b manufactured by the manufacturing method of the present invention has the following characteristics. The all-solid-state battery 1b manufactured by the manufacturing method of the present invention has plasma treatment applied to the interface between the positive electrode 17 and the solid electrolyte portion 15, and has good cycle characteristics.

[0063] The all-solid-state battery 1b comprises a positive electrode 17, a solid electrolyte portion 15, and a negative electrode 14 in this order. The positive electrode 17 includes a positive electrode active material 27 and a first solid electrolyte 26, and the solid electrolyte portion 15 consists of a second solid electrolyte 25.

[0064] The all-solid-state battery 1b has a plasma treatment applied to the surface of the solid electrolyte portion 15 side of the positive electrode 17 after molding, and has a plasma ashing portion 16 (plasma treatment portion).

[0065] The all-solid-state battery 1b manufactured by the manufacturing method of the present invention can reduce internal resistance by comprising a solid electrolyte section 15 consisting of a sulfide solid electrolyte (second solid electrolyte 25) with high ionic conductivity.

[0066] In the all-solid-state battery 1b manufactured by the manufacturing method of the present invention, by further performing plasma treatment on the interface between the positive electrode 17 and the solid electrolyte portion 15, preferably on the solid electrolyte portion 15 side of the positive electrode 17, the interface region in which the oxide positive electrode active material 27 and the sulfide second solid electrolyte 25 come into direct contact is almost eliminated, thereby suppressing the amount of sulfur contained in the second solid electrolyte 25 diffusing into the positive electrode active material 27.

[0067] The all-solid-state battery 1b manufactured by the manufacturing method of the present invention has suppressed degradation of the positive electrode active material 27 and improved cycle characteristics. Furthermore, since the all-solid-state battery 1b manufactured by the manufacturing method of the present invention is subjected to plasma treatment only at the interface between the positive electrode 17 and the solid electrolyte portion 15, it has a higher energy density and can suppress an increase in internal resistance compared to coating the entire positive electrode active material 27 (powder).

[0068] The following examples illustrate the all-solid-state battery 1b manufactured by the manufacturing method of the present invention.

[0069] However, the present invention is not limited to the examples provided.

[0070] In the examples, "%" for gas refers to "volume flow rate %" unless otherwise specified.

[0071] [1] Manufacturing of all-solid-state batteries A coin-shaped all-solid-state battery 1b with a diameter of approximately φ10 mm was fabricated and its charge and discharge performance was evaluated.

[0072] First, the positive electrode active material 27 (LiNi 0.5 Co 0.2 Mn 0.3 O2) and solid electrolyte (Li 1.3 Al 0.3 Ti 1.7 (PO4)3: The first solid electrolyte 26) was mixed with a binder (polyvinylidene fluoride) and a conductive additive (acetylene black), and the mixture was compacted to produce the positive electrode 17.

[0073] Next, the surface of the positive electrode 17 was subjected to plasma treatment for 10 minutes under the conditions of an atmosphere containing oxygen (5%) and argon (95%), a pressure of 0.8 Pa, a high-frequency power of 100 W, and room temperature.

[0074] Finally, a compacted solid electrolyte 15 (Li6PS5Cl: second solid electrolyte 25) was laminated onto the plasma-treated side of the positive electrode 17, and the negative electrode 14 (Li / In) was laminated on top of it.

[0075] [2] Evaluation Figure 5 of the all-solid-state battery illustrates the cycle characteristics of an all-solid-state battery 1b having a plasma ashing section 16 (plasma processing section) manufactured by the manufacturing method of the present invention, compared with an example without plasma processing.

[0076] The charge and discharge capacity was evaluated under the conditions of a voltage range of 1.9V to 3.7V and a charge / discharge rate of 0.1CA.

[0077] The all-solid-state battery 1b manufactured by the manufacturing method of the present invention has a plasma treatment applied to the surface of the positive electrode 17 on the solid electrolyte portion 15 side. After aging, the decrease in discharge capacity was significantly less and the cycle characteristics were better compared to an example without plasma treatment. This is because the surface of the positive electrode 17 was surface-modified by the plasma treatment.

[0078] It is believed that good bonding was formed between the positive electrode 17 and the solid electrolyte layer (solid electrolyte portion 15) by removing excess binder, conductive additives, etc., from the surface of the positive electrode 17, or by removing adsorbed moisture, etc., and by suppressing excess interfacial reactions with moisture, etc., good cycle characteristics were obtained.

[0079] From the evaluation of the charge and discharge capacity, it is thought that the strong oxidation of the surface suppressed the diffusion of sulfur contained in the second solid electrolyte 25 into the positive electrode active material 27.

[0080] However, these factors and mechanisms are speculative and do not limit the technical scope of this disclosure.

[0081] All-solid-state batteries manufactured by the manufacturing method of the present invention can have improved cycle characteristics. All-solid-state batteries manufactured by the manufacturing method of the present invention can have a high energy density and suppress an increase in internal resistance.

[0082] 1a (Conventional) All-solid-state battery 11 Negative electrode 12 Solid electrolyte section 13 Positive electrode 1b (Manufactured by the manufacturing method of the present invention) All-solid-state battery 14 Negative electrode 15 Solid electrolyte section 16 Plasma ashing section (plasma processing section) 17 Positive electrode 21 Second solid electrolyte 22 First solid electrolyte 23 Positive electrode active material 24 Coating film 25 Second solid electrolyte 26 First solid electrolyte 27 Positive electrode active material 4a Load lock chamber 4b Plasma processing chamber 41 Gas piping 42, 43 Vacuum piping 44 Vessel 44a Vessel plate 44b Vessel cover 44c Sample holder 44d Screw fastening section (of the opening / closing drive section) 44e Dovetail groove for O-ring 46 Processing chamber 47 Sample transport mechanism 48 Antenna

Claims

1. A method for manufacturing an all-solid-state battery, comprising: (1) a step of molding a positive electrode with a mixture containing a positive electrode active material and a first solid electrolyte; (2) a step of molding a solid electrolyte portion with a second solid electrolyte; (3) a step of applying plasma treatment to the surface of the molded positive electrode on the solid electrolyte portion side; and (4) a step of stacking the positive electrode, the solid electrolyte portion, and the negative electrode in this order and pressing them together.

2. The method for manufacturing an all-solid-state battery according to claim 1, wherein the positive electrode active material and the first solid electrolyte are oxides, and the second solid electrolyte is a sulfide.

3. The method for manufacturing an all-solid-state battery according to claim 1, wherein steps (1) and (2) are carried out in a first environment with a dew point of -60°C or lower, step (3) is carried out in a second environment with a pressure of approximately 100 Pa or lower, and step (5) includes a step of transporting a sample between the first environment and the second environment, and step (5) includes storing the sample in a vacuum-sealed vessel.

4. The method for manufacturing an all-solid-state battery according to claim 1, wherein the positive electrode active material comprises lithium (Li), nickel (Ni), manganese (Mn), cobalt (Co), and oxygen (O), the first solid electrolyte comprises lithium (Li), aluminum (Al), titanium (Ti), phosphorus (P), and oxygen (O), and the second solid electrolyte comprises lithium (Li), phosphorus (P), sulfur (S), and chlorine (Cl).

5. The positive electrode active material is LiNi 0.5 Mn 0.2 Co 0.3 The first solid electrolyte is O2, and the previous solid electrolyte is Li 1.3 Al 0.3 Ti 1.7 A method for manufacturing an all-solid-state battery according to claim 1, wherein the second solid electrolyte is (PO4)3 and Li6PS5Cl.

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