Solid-state battery, method for manufacturing same, and battery module

Abstract

The invention relates to a solid-state battery, a method for manufacturing the same, and a battery module. Provided is a solid-state battery in which the reliability of insulation by an insulating member is high. A solid-state battery (10) according to the present disclosure has an electrode laminate (110). The electrode laminate has a first current collector layer (111), a first electrode active material layer (112), a solid electrolyte layer (113), a second electrode active material layer (114), and a second current collector layer (115) in this order. An insulating member (120) is disposed on at least a portion of an end surface of the electrode laminate. The second current collector layer extends from an end surface of the electrode laminate in which the insulating member is disposed, and the insulating member is bonded to the electrode laminate and the second current collector layer. The insulating member extends from an end surface of the electrode laminate along the second current collector layer.

Description

Technical Field

[0001] The present disclosure relates to a solid battery, a method for manufacturing the same, and a battery module. Background Art

[0002] In the automotive industry, growing awareness of environmental issues has led to the development of electric and hybrid vehicles, resulting in a growing demand for high-voltage secondary batteries. Meanwhile, in the field of mobile electronic devices, the widespread adoption and development of these devices has led to a demand for high-capacity secondary batteries that are compact, lightweight, and capable of long-term continuous operation.

[0003] As a high-voltage and high-capacity battery, for example, a battery including an electrode stack having a negative electrode current collector layer, a negative electrode active material layer, a solid electrolyte layer, a positive electrode active material layer, and a positive electrode current collector layer in this order is known.

[0004] In such batteries, for example, when the current collector layer of one electrode extends from the electrode stack, it may come into contact with the current collector layer and / or active material layer of the other electrode, causing a short circuit. Furthermore, the portion of the current collector layer that extends from the electrode stack is also referred to as the collector tab. This short circuit is particularly likely to occur when the area of ​​the current collector layer of one electrode is larger than that of the other electrode. Therefore, technologies are being developed to prevent such short circuits.

[0005] For example, Patent Document 1 discloses a method for manufacturing a stacked all-solid-state battery, which is a method for manufacturing a stacked all-solid-state battery, comprising: preparing a first stack in which a solid electrolyte layer, a first active material layer (electrode active material layer), a first collector layer having a first collector sheet extending on the side of the stacked all-solid-state battery, a first active material layer and a solid electrolyte layer are stacked in sequence; applying an insulator coating liquid on the end of the first stack to form an insulating portion (insulating component); stacking the first stack in which the insulating portion is formed, a second active material layer, and a second collector layer having a second collector sheet extending on the side of the stacked all-solid-state battery, preparing a battery structure (electrode stack) having a plurality of second stacks in which a second collector layer having a second collector sheet, a second active material layer, a solid electrolyte layer, a first active material layer, a first collector layer having a first collector sheet, a first active material layer, a solid electrolyte layer, and a second active material layer are stacked in sequence; and joining a plurality of second collector sheets extending from a plurality of second collectors in the battery structure.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2018-049696 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] The inventors of the present application discovered that when an insulating component is applied to the end face of a preliminary stack composed of layers other than the second collector layer in an electrode stack, and the second collector layer is stacked on the preliminary stack to produce an electrode stack, interference sometimes occurs between the second collector layer and the insulating component. As a result, the insulating component sometimes peels off from the electrode stack, and the reliability of the insulation provided by the insulating component is reduced.

[0011] An object of the present disclosure is to provide a solid battery having highly reliable insulation by an insulating member, a method for manufacturing the same, and a battery module including the solid battery.

[0012] Means for solving problems

[0013] The inventors of the present application have discovered that the above-mentioned problems can be solved by the following means.

[0014] <Scheme 1>

[0015] A solid battery is a solid battery having an electrode stack, wherein the electrode stack has a first collector layer, a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, and a second collector layer in sequence, an insulating member is arranged on at least a portion of the end surface of the electrode stack, the second collector layer extends from the end surface of the electrode stack on which the insulating member is arranged, the insulating member is bonded to the electrode stack and the second collector layer, and the insulating member extends from the end surface of the electrode stack along the second collector layer.

[0016] Option 2

[0017] A solid battery according to Option 1, wherein the electrode stack has the first electrode active material layer, the solid electrolyte layer, the second electrode active material layer, and the second collector layer in sequence on both sides of the first collector layer, and the insulating member is bonded to the electrode stack and the two second collector layers.

[0018] <Scheme 3>

[0019] The solid battery according to aspect 1 or 2, wherein the insulating member has a shape that is recessed toward the electrode stack.

[0020] Option 4

[0021] The solid battery according to any one of options 1 to 3, wherein the first current collector layer is a negative electrode current collector layer, the first electrode active material layer is a negative electrode active material layer, the second electrode active material layer is a positive electrode active material layer, and the second current collector layer is a positive electrode current collector layer.

[0022] <Scheme 5>

[0023] A battery module comprising the solid state battery of Option 4.

[0024] <Scheme 6>

[0025] The method for manufacturing a solid battery according to any one of embodiments 1 to 3, comprising the following steps:

[0026] (a) stacking the first current collector layer, the first electrode active material layer, the solid electrolyte layer, and the second electrode active material layer in this order to form a preliminary stack;

[0027] (b) applying the insulating member to a portion of the second current collector layer;

[0028] (c) laminating the second current collector layer on the main surface of the preliminary stack so that the end surface of the preliminary stack and the insulating member coincide with each other in the plane direction of the preliminary stack;

[0029] (d) pressing the second current collector layer to cause the insulating member to flow toward the end surface of the preliminary stack, thereby forming the electrode stack having the insulating member disposed on at least a portion of the end surface; and

[0030] (e) solidifying the insulating member.

[0031] <Scheme 7>

[0032] The method according to claim 6, wherein the insulating member comprises a thermoplastic resin, and in the step (d), the step further includes melting the thermoplastic resin, causing the insulating member comprising the molten thermoplastic resin to flow on the end surface of the preliminary laminate, and in the step (e), solidifying the insulating member comprising the molten thermoplastic resin.

[0033] <Scheme 8>

[0034] The method according to claim 6, wherein the insulating member is a curable resin, and in the step (e), the insulating member containing the curable resin is cured to solidify.

[0035] <Scheme 9>

[0036] The method for manufacturing a solid battery according to any one of embodiments 1 to 3, comprising the following steps:

[0037] (a) stacking the first electrode active material layer, the solid electrolyte layer, and the second electrode active material layer in this order on both sides of the first current collector layer to form a preliminary stack;

[0038] (b) laminating a first second current collector layer on one main surface of the preliminary laminate;

[0039] (c) applying the insulating member to at least a portion of an end surface of the preliminary laminate and a portion of the first second current collector layer extending from the preliminary laminate;

[0040] (d) laminating a second second current collector layer on the other main surface of the preliminary laminate;

[0041] (e) pressing a second second current collector layer to form the electrode stack having the insulating member disposed on an end surface thereof; and

[0042] (f) solidifying the insulating member.

[0043] <Scheme 10>

[0044] The method according to claim 9, wherein the insulating member contains a thermoplastic resin, and in the step (c), the insulating member containing the thermoplastic resin is further melted, and in the step (f), the insulating member containing the molten thermoplastic resin is solidified.

[0045] Plan 11

[0046] The method according to claim 9, wherein the insulating member contains a curable resin, and in the step (f), the insulating member containing the curable resin is cured to solidify.

[0047] Effects of the Invention

[0048] According to the present disclosure, it is possible to provide a solid battery having highly reliable insulation by an insulating member, a method for manufacturing the same, and a battery module including the solid battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic plan view showing an example of the solid state battery of the present disclosure.

[0050] Figure 2 This is a schematic cross-sectional view showing an example of the arrangement of insulating members in the solid battery of the present disclosure.

[0051] Figure 3This is a schematic cross-sectional view showing an example of the arrangement of insulating members in the solid battery of the present disclosure.

[0052] Figure 4 This is a schematic diagram showing an example of the method of the present disclosure for manufacturing a solid state battery.

[0053] Figure 5 This is a schematic diagram for explaining the positional relationship between a preliminary stack and an insulating member in the method of the present disclosure for manufacturing a solid battery.

[0054] Figure 6 This is a schematic diagram showing an example of the method of the present disclosure for manufacturing a solid state battery.

[0055] Figure 7 This is a schematic perspective view showing an example of a battery module of the present disclosure.

[0056] Description of Reference Signs

[0057] 1 battery module

[0058] 10 Solid-state batteries

[0059] 100 Preparatory laminate

[0060] 110 electrode stack

[0061] 111 First current collector layer

[0062] 112 first electrode active material layer

[0063] 113 Solid Electrolyte Layer

[0064] 114 Second electrode active material layer

[0065] 115 Second current collector layer

[0066] 120 Insulation components

[0067] 130 Laminated Film

[0068] 140 collector terminal DETAILED DESCRIPTION

[0069] The following describes the embodiments of the present disclosure in detail with reference to the accompanying drawings. Furthermore, the present disclosure is not limited to the following embodiments and can be implemented in various modifications within the scope of the disclosed subject matter. Furthermore, the dimensional relationships in the accompanying drawings do not reflect the actual dimensional relationships.

[0070] Solid-State Battery

[0071] like Figure 1 As shown in FIG, the solid battery 10 of the present disclosure includes an electrode stack 110. Figure 2 and3 As shown in the example, the electrode stack has a first collector layer 111, a first electrode active material layer 112, a solid electrolyte layer 113, a second electrode active material layer 114, and a second collector layer 115 in this order. An insulating member 120 is arranged on at least a portion of the end face of the electrode stack. The second collector layer extends from the end face of the electrode stack on which the insulating member is arranged, and the insulating member is bonded to the electrode stack and the second collector layer. The insulating member extends from the end face of the electrode stack along the second collector layer. Furthermore, Figure 2 and 3 This is a schematic cross-sectional view showing an enlarged portion of the insulating member 120 of the solid battery 10 of the present disclosure.

[0072] The inventors of this application have discovered that by configuring the insulating member to be bonded to the electrode stack and the second current collector layer, and extending from the end surface of the electrode stack along the second current collector layer, the reliability of the insulation provided by the insulating member is improved. This is believed to be due to the insulating member being bonded to the electrode stack and the second current collector layer, making it less likely for the insulating member to fall off the electrode stack.

[0073] Furthermore, it is considered that since the insulating member extends from the end surface of the electrode stack along the second current collector layer, the insulating member can reinforce the second current collector layer and make it difficult to break.

[0074] like Figure 2 and 3 As illustrated in the example, the electrode stack may include a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, and a second current collector layer in this order on both sides of the first current collector layer, and the insulating member may be bonded to the electrode stack and the two second current collector layers. This configuration can more effectively prevent the insulating member from falling off the electrode stack, thereby improving the reliability of the insulation provided by the insulating member.

[0075] In the present disclosure, a "solid-state battery" refers to a battery that uses at least a solid electrolyte as an electrolyte. Thus, a solid-state battery may use a combination of a solid electrolyte and a liquid electrolyte as an electrolyte. Furthermore, the solid-state battery of the present disclosure may be an all-solid-state battery, i.e., a battery that uses only a solid electrolyte as an electrolyte.

[0076] The solid battery of the present disclosure may be a lithium ion secondary battery. As the purpose of the battery, for example, a power source for vehicles such as hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), electric vehicles (BEV), gasoline vehicles, and diesel vehicles can be listed. It is particularly preferably used as a driving power source for hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), or electric vehicles (BEV). In addition, the battery in the present disclosure can be used as a power source for mobile bodies (such as railways, ships, and aircraft) other than vehicles, and can also be used as a power source for electrical products such as information processing devices.

[0077] The elements constituting the solid state battery of the present disclosure are described below.

[0078] <Electrode stack>

[0079] The solid battery 10 disclosed in the present invention has an electrode stack 110. The electrode stack functions as a power generation element of the battery. Figure 2 and 3 As illustrated in , the electrode stack may include, in order, a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, and a second current collector layer on both sides of the first current collector layer. That is, the electrode stack may include, in order, a second current collector layer, a second electrode active material layer, a solid electrolyte layer, a first electrode active material layer, a first current collector layer, a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, and a second current collector layer.

[0080] The first current collector layer may be a negative electrode current collector layer, the first electrode active material layer may be a negative electrode active material layer, the second electrode active material layer may be a positive electrode active material layer, and the second current collector layer may be a positive electrode current collector layer. That is, the electrode stack may include, in this order, a negative electrode current collector layer, a negative electrode active material layer, a solid electrolyte layer, a positive electrode active material layer, and a positive electrode current collector layer.

[0081] There is no particular limitation on the shape of the electrode stack. For example, it may have a top portion, a bottom portion opposite to the top portion, and four side portions connecting the top portion and the bottom portion. There is no particular limitation on the shape of the top portion. For example, quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms can be listed. In addition, the shape of the top portion may be a polygon other than a quadrilateral, or a shape with a curve such as a circle. The shape of the bottom portion may be the same as that of the top portion. There is no particular limitation on the shape of the side portions. For example, quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms can be listed.

[0082] The size of the electrode stack is not particularly limited and can be appropriately designed according to, for example, desired battery characteristics and the like.

[0083] Hereinafter, each member that can constitute the electrode stack according to the present disclosure will be described.

[0084] To facilitate understanding of the present disclosure, each member related to an electrode stack of a solid lithium ion secondary battery will be described as an example; however, the solid battery of the present disclosure is not limited to a lithium ion secondary battery.

[0085] (Positive electrode current collector layer)

[0086] The conductive material used for the positive electrode current collector layer is not particularly limited, and examples thereof include SUS, aluminum, copper, nickel, iron, titanium, and carbon.

[0087] The shape of the positive electrode current collector layer is not particularly limited, and examples thereof include foil, plate, and mesh. Among these, foil is preferred.

[0088] The positive electrode current collector layer may extend from the end surface of the electrode stack, and a plurality of positive electrode current collector layers may be joined at the extended portion.

[0089] (Positive Electrode Active Material Layer)

[0090] The positive electrode active material layer contains at least a positive electrode active material and preferably further contains a solid electrolyte described below. In addition, depending on the application and purpose of use, for example, an additive used in the positive electrode active material layer of a solid battery, such as a conductive additive or a binder, may be contained.

[0091] There is no particular limitation on the material of the positive electrode active material. For example, the positive electrode active material may be lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganese oxide (LiMn2O4), Li 1.5 Co 1 / 3 Ni 1 / 3 Mn 1 / 3 O2、LiCo 1 / 3 Ni 1 / 3 Mn 1 / 3 O2, by Li 1+x Mn 2-x-y M y A heterogeneous element-substituted Li-Mn spinel having a composition represented by O4 (M is one or more metal elements selected from Al, Mg, Co, Fe, Ni and Zn) or the like.

[0092] The conductive additive is not particularly limited, and may be, for example, a carbon material such as VGCF (Vapor Grown Carbon Fiber) or carbon nanofiber, or a metal material.

[0093] The binder is not particularly limited, and may be, for example, polyvinylidene fluoride (PVdF), carboxymethyl cellulose (CMC), butadiene rubber (BR), styrene butadiene rubber (SBR), or a combination thereof.

[0094] (Solid electrolyte layer)

[0095] The solid electrolyte layer contains at least a solid electrolyte. The solid electrolyte is not particularly limited, and any material that can be used as a solid electrolyte for solid batteries can be used. For example, the solid electrolyte can be a sulfide solid electrolyte, an oxide solid electrolyte, or a polymer electrolyte.

[0096] Examples of sulfide solid electrolytes include sulfide-based amorphous solid electrolytes, sulfide-based crystalline solid electrolytes, and argyrodite-type solid electrolytes, but are not limited thereto. Specific examples of sulfide solid electrolytes include Li2S-P2S5 (Li7P3S 11 , Li3PS4, Li8P2S9, etc.), Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-LiBr-Li2S-P2S5, Li2S-P2S5-GeS2 (Li 13 GeP3S 16 、Li 10 GeP2S 12 etc.), LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li 7-x PS 6-x Cl x etc.; or combinations thereof, but not limited thereto.

[0097] Examples of oxide solid electrolytes include Li7La3Zr2O 12、 Li 7-x La3Zr 1-x Nb x O 12、 Li 7- 3x La3Zr2Al x O 12 、Li 3x La 2 / 3-x TiO3、Li 1+x Al x Ti 2-x (PO4)3、Li 1+x Al x Ge 2-x (PO4)3, Li3PO4, Li 3+x PO 4-x N x (LiPON), etc., but not limited to these.

[0098] Examples of the polymer electrolyte include polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof, but the polymer electrolyte is not limited thereto.

[0099] The solid electrolyte may be glass or crystallized glass (glass ceramic). In addition, the solid electrolyte layer may contain a conductive additive, a binder, etc. as needed in addition to the above-mentioned solid electrolyte. For the conductive additive and the binder, reference can be made to the description related to the positive electrode active material layer.

[0100] (Negative Electrode Active Material Layer)

[0101] The negative electrode active material layer contains at least a negative electrode active material and preferably further contains the above-mentioned solid electrolyte. In addition, depending on the application and purpose of use, for example, a conductive additive, a binder, and other additives used in the negative electrode active material layer of a solid battery may be contained.

[0102] The material of the negative electrode active material is not particularly limited, but preferably can occlude and release metal ions such as lithium ions. For example, the negative electrode active material can be an oxide-based negative electrode active material, an alloy-based negative electrode active material, a carbon material, etc., but is not limited to these.

[0103] The oxide-based negative electrode active material is not particularly limited, and examples thereof include lithium titanate (LTO) particles.

[0104] There is no particular limitation on the alloy-based negative electrode active material, and examples thereof include Si alloy-based negative electrode active materials and Sn alloy-based negative electrode active materials. Examples of Si alloy-based negative electrode active materials include silicon, silicon oxide, silicon carbide, silicon nitride, or solid solutions thereof. In addition, Si alloy-based negative electrode active materials may contain elements other than silicon, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, etc. In addition, Sn alloy-based negative electrode active materials may contain elements other than silicon, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, etc. In addition, Sn alloy-based negative electrode active materials may contain elements other than tin, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, etc.

[0105] The carbon material is not particularly limited, and examples thereof include hard carbon, soft carbon, and graphite.

[0106] Regarding the solid electrolyte used for the negative electrode active material layer, reference can be made to the above description regarding the solid electrolyte layer. Regarding the conductive additive and the binder, reference can be made to the above description regarding the positive electrode active material layer.

[0107] (Negative electrode current collector layer)

[0108] The conductive material used for the negative electrode current collector layer is not particularly limited, and examples thereof include SUS, aluminum, copper, nickel, iron, titanium, carbon, etc., but are not limited thereto.

[0109] The shape of the negative electrode current collector layer is not particularly limited, and examples thereof include foil, plate, and mesh. Among these, foil is preferred.

[0110] The negative electrode current collector layer may extend from the end surface of the electrode stack, and a plurality of negative electrode current collector layers may be joined at the extended portion.

[0111] <Insulation components>

[0112] like Figure 2 and 3 As shown in the example, the insulating member 120 may have a shape that is concave toward the electrode stack 110. This configuration improves the insulating member's ability to follow the bending of the second current collector layer compared to a configuration in which the insulating member does not have a concave shape toward the electrode stack, thereby improving the reliability of the insulation provided by the insulating member. Furthermore, the amount of material used in the insulating member can be reduced.

[0113] When the insulating member has a shape that is concave toward the electrode stack, the length L1 of the portion of the insulating member that contacts the second collector layer may be greater than 100 μm, greater than 300 μm, greater than 500 μm, or greater than 1 mm, or less than 3 mm, less than 2 mm, or less than 1 mm, or less than 500 μm. By adopting such a structure, the second collector layer can be appropriately reinforced. In addition, the second collector layer can be reinforced without excessively damaging the surface direction of the electrode stack, that is, Figure 2 and 3 Insulating members are configured in the case of volume efficiency in the x direction.

[0114] In the case where the insulating member has a shape that is concave toward the electrode stack, the length L2 from the end face of the electrode stack to the apex of the concave portion may be greater than 10 μm, greater than 20 μm, greater than 30 μm, 50 μm, or greater than 100 μm, and may be less than 500 μm, less than 300 μm, or less than 100 μm. By adopting such a structure, the insulation provided by the insulating member can be ensured, and the amount of material used for the insulating member can be reduced. Figure 2 In the embodiment, the concave portion may be formed near the center of the electrode stack in the stacking direction and two concave portions formed along the second current collector layer. Figure 2 In the embodiment, the length L2 of each recess is equal, but the length L2 of each recess may be different.

[0115] The insulating member 120 may include a thermoplastic resin, and may be a thermoplastic resin. The thermoplastic resin is not particularly limited and may be either non-reactive or reactive. Non-reactive thermoplastic resins are not particularly limited, and examples include ethylene vinyl acetate (EVA), synthetic rubber, olefin, polyamide, or polyester resins such as polyethylene terephthalate (PET). Reactive resins are not particularly limited, and examples include polyurethane resins.

[0116] The insulating member 120 may include a curable resin. The curable resin is not particularly limited, and examples thereof include thermosetting resins and photocurable resins. Examples of these resins include acrylic and epoxy resins.

[0117] The shape of the insulating member 120 is not particularly limited, and as described above, may be a shape that is recessed toward the electrode stack 110 .

[0118] The size of the insulating member 120 is not particularly limited and can be appropriately designed in consideration of the volume efficiency of the battery and the like.

[0119] Laminated film

[0120] The solid-state battery 10 of the present disclosure may include a laminate film 130. The laminate film may accommodate an electrode stack. Specifically, the laminate film may be wound around the electrode stack to accommodate the electrode stack. Alternatively, the laminate film may be composed of a first film and a second film. In this case, the first and second films may be used to sandwich the electrode stack from above and below in the stacking direction of the electrode stack to accommodate the stack.

[0121] The laminate film may include a sealant resin layer, a metal layer, and a protective resin layer in this order along the thickness direction. Examples of materials for the sealant resin layer include olefin resins such as polypropylene (PP) and polyethylene (PE). Examples of materials for the metal layer include aluminum, aluminum alloys, and stainless steel. Examples of materials for the protective resin layer include polyethylene terephthalate (PET) and nylon.

[0122] There are no particular limitations on the layers comprising the laminate film or the thickness of the laminate film. The thickness of the sealant resin layer is, for example, 40 μm to 100 μm. The thickness of the metal layer is, for example, 30 μm to 60 μm. The thickness of the protective resin layer is, for example, 20 μm to 60 μm. The thickness of the laminate film is, for example, 80 μm to 250 μm.

[0123] 〈Current collector terminal〉

[0124] The solid battery 10 of the present disclosure may further include a collector terminal 140. The collector terminal may be electrically connected to the collector portion of the electrode stack. The material of the collector terminal is not particularly limited as long as it has a collector function. Figure 1 As shown in the example, the positive electrode current collecting terminal and the negative electrode current collecting terminal may be arranged on a pair of opposing side surfaces of the electrode stack. The positive electrode current collecting terminal and the negative electrode current collecting terminal may be arranged separately from each other on one side surface of the electrode stack.

[0125] The shape, size, etc. of the current collecting terminal are not particularly limited.

[0126] In the case where the solid battery of the present disclosure has a current collector terminal, the laminated film can accommodate the electrode stack and the current collector terminal together. Specifically, the laminated film can wind the electrode stack and the current collector terminal together to accommodate the electrode stack and the current collector terminal. Alternatively, the laminated film can be composed of a first film and a second film. In this case, the first film and the second film can be used to clamp the electrode stack and the current collector terminal from above and below in the stacking direction of the electrode stack, thereby accommodating the electrode stack and the current collector terminal together.

[0127] Manufacturing Methods of Solid-State Batteries

[0128] Next, a first method of the present disclosure for manufacturing the solid state battery 10 will be described.

[0129] like Figure 4 As illustrated in FIG, the method of the present disclosure for manufacturing a solid battery 10 includes the following steps: (a) stacking a first collector layer 111, a first electrode active material layer 112, a solid electrolyte layer 113, and a second electrode active material layer 114 in sequence to form a preliminary stack 100; (b) applying an insulating member 120 to a portion of the second collector layer 115; (c) stacking the second collector layer 115 on the main surface of the preliminary stack 100 in a manner such that the end face of the electrode stack 110 and the insulating member 120 match in the surface direction of the preliminary stack 100; (d) extruding the second collector layer 115 so that the insulating member 120 flows on the end face of the preliminary stack 100 to form an electrode stack 110 having the insulating member 120 configured on at least a portion of the end face; and (e) solidifying the insulating member 120.

[0130] Specifically, according to the method disclosed herein, an insulating member is applied to connect the end face of the electrode stack to the second current collector layer. Furthermore, the method disclosed herein includes solidifying the insulating member. This secures the insulating member to the electrode stack, making it difficult for the insulating member to peel from the electrode stack. Consequently, the reliability of the insulation provided by the insulating member can be improved.

[0131] Furthermore, the method disclosed herein includes pressing the second current collector layer to allow the insulating member to flow along the end surface of the preliminary laminate. Therefore, the thickness of the solid battery manufactured using the method disclosed herein becomes substantially uniform, thereby improving the volumetric efficiency of the battery.

[0132] In the present disclosure, the term "preliminary stack" refers to a stack that includes a first current collector layer, a first electrode active material layer, a solid electrolyte layer, and a second electrode active material layer in this order, and can be formed into an electrode stack by stacking the second current collector layer.

[0133] <Preliminary laminate formation step>

[0134] The method disclosed herein includes: (a) sequentially stacking a first current collector layer 111 , a first electrode active material layer 112 , a solid electrolyte layer 113 , and a second electrode active material layer 114 to form a preliminary stack 100 .

[0135] There is no particular limitation on the method for stacking the layers, and examples include dry forming such as powder pressing and wet forming using a slurry. For example, in the case of wet forming, first, a first electrode composite slurry capable of forming a first electrode active material layer is applied to one side of the first current collector layer and dried, thereby enabling the first electrode active material layer to be stacked on the first current collector layer. A solid electrolyte slurry is used to similarly stack the solid electrolyte layer on the first electrode active material layer. A second electrode composite slurry is used to similarly stack the second electrode active material layer on the solid electrolyte layer.

[0136] right Figure 5 The height H of the preliminary stack shown in , i.e., the length in the stacking direction, is not particularly limited, and may be, for example, 50 μm or more, 100 μm or more, or 150 μm or less, 500 μm or less, 300 μm or less, 200 μm or less, or 150 μm or less.

[0137] 〈Insulation component application process〉

[0138] like Figure 4 As illustrated in (a), the method of the present disclosure includes: (b) applying an insulating member 120 to a portion of the second current collector layer 115 .

[0139] In step (b), the “part” can be defined by the length L3 of the insulating member in the x direction (the surface direction of the electrode stack) (see Figure 5 For example, the length L3 may be greater than or equal to 100 μm, greater than or equal to 500 μm, greater than or equal to 1 mm, or greater than or equal to 2 mm, and may be less than or equal to 5 mm, less than or equal to 4 mm, less than or equal to 3 mm, or less than or equal to 2 mm.

[0140] The amount of the insulating member applied to the second current collector layer can be determined by the thickness T of the insulating member (the length of the electrode stack in the stacking direction) (see Figure 5For example, the thickness T may be greater than or equal to 10 μm, greater than or equal to 50 μm, greater than or equal to 75 μm, or greater than or equal to 100 μm, and may be less than or equal to 300 μm, less than or equal to 200 μm, less than or equal to 150 μm, or less than or equal to 100 μm.

[0141] The method of applying the insulating member is not particularly limited, and an example thereof includes a method of coating the insulating member.

[0142] <Second Current Collector Layer Lamination Step>

[0143] like Figure 4 As illustrated in (b), the method of the present disclosure includes: (c) laminating the second current collector layer 115 on the main surface of the preliminary stack 100 so that the end surface of the preliminary stack 100 matches the insulating member 120 in the plane direction of the preliminary stack 100 .

[0144] The position at which the second current collector layer is stacked can be determined by the length L1 of the portion of the insulating member extending from the end surface of the electrode stack. As described above, for example, the length L1 can be 100 μm or greater, 300 μm or greater, 500 μm or greater, or 1 mm or greater, and can be 3 mm or less, 2 mm or less, 1 mm or less, or 500 μm or less.

[0145] For thickness T, length L1 and height H, the following relationship can be satisfied:

[0146] T(μm)×L1(mm)×1000>10(μm)×H(μm) / 2.

[0147] By satisfying this relational expression, the insulation performance of the insulating member can be ensured without substantially increasing the thickness of the battery in the portion where the insulating member is applied. In addition, by satisfying this relational expression, it is easy to make the insulating member have a shape that is concave toward the electrode stack (see Figure 2 and 4 (c)).

[0148] <Electrode stack formation step>

[0149] like Figure 4 As illustrated in (b) and (c), the method of the present disclosure includes: (d) pressing the second current collector layer 115 to flow the insulating member 120 on the end surface of the preliminary stack 100 to form the electrode stack 110 with the insulating member 120 disposed on the end surface.

[0150] The method of pressing the second current collector layer is not particularly limited, and examples thereof include: Figure 4 As shown in (b), a method of extrusion using an extrusion member is used.

[0151] The direction of extrusion is not particularly limited. For example, the second current collector layer can be extruded in the direction in which the preliminary stack is stacked. In particular, the second current collector layer can be extruded so as to apply a force toward the end surface of the preliminary stack. By applying a force toward the end surface of the preliminary stack, the insulating member can be effectively flowed along the end surface of the preliminary stack.

[0152] <Insulation Component Solidification Step>

[0153] The method of the present disclosure includes: (e) solidifying the insulating member 120 .

[0154] In the method disclosed herein, the insulating member may comprise a thermoplastic resin. In this case, step (d) may further comprise melting the thermoplastic resin, causing the insulating member comprising the molten thermoplastic resin to flow on the end surface of the preliminary laminate, and step (e) may comprise solidifying the insulating member comprising the molten thermoplastic resin.

[0155] Regarding the thermoplastic resin, reference can be made to the above description regarding the solid state battery of the present disclosure.

[0156] When the insulating member comprises a thermoplastic resin, the second current collector layer can be heated to melt the thermoplastic resin, and then the second current collector layer can be pressed to allow the insulating member comprising the molten thermoplastic resin to flow along the end surface of the preliminary laminate. In particular, for example, heating and pressing of the second current collector layer can be performed simultaneously using a heating rod or the like.

[0157] The method for solidifying the insulating member containing the molten thermoplastic resin is not particularly limited, and examples thereof include a method of cooling the insulating member. The method for cooling the insulating member is not particularly limited, and examples thereof include a method of air cooling.

[0158] In the method of the present disclosure, the insulating member may be a curable resin. In this case, in step (e), the insulating member containing the curable resin may be solidified by curing.

[0159] Regarding the curable resin, reference can be made to the above description related to the solid state battery of the present disclosure.

[0160] The method for curing the insulating member containing a curable resin is not particularly limited. For example, if the curable resin is a photocurable resin, it can be cured by irradiating the curable resin with ultraviolet light, etc. If the curable resin is a thermosetting resin, it can be cured by heating the curable resin.

[0161] Next, a second method of the present disclosure for manufacturing the solid state battery 10 will be described.

[0162] like Figure 6 As illustrated in the figure, the method of the present disclosure for manufacturing a solid battery includes the following steps: (a) stacking a first electrode active material layer 112, a solid electrolyte layer 113 and a second electrode active material layer 114 in sequence on both sides of a first collector layer 111 to form a preliminary stack 100; (b) stacking a first second collector layer 115 on one main surface of the preliminary stack 100; (c) applying an insulating component 120 to at least a portion of the end surface of the preliminary stack 100 and the portion of the first second collector layer 115 extending from the preliminary stack 100; (d) stacking a second second collector layer 115 on another main surface in the preliminary stack 100; (e) extruding the second second collector layer 115 to form an electrode stack 110 with the insulating component 120 configured on the end surface; and (f) solidifying the insulating component 120.

[0163] Specifically, the method disclosed herein involves curing an insulating member applied to connect the end face of the electrode stack to the second current collector layer. This secures the insulating member to the electrode stack, making it difficult for the insulating member to peel from the electrode stack. Consequently, the reliability of the insulation provided by the insulating member can be improved.

[0164] Furthermore, the method disclosed herein includes compressing the second current collector layer to crush the insulating member, thereby forming an electrode stack having the insulating member disposed on the end face. Therefore, the thickness of the solid battery manufactured using the method disclosed herein becomes substantially uniform, resulting in improved volumetric efficiency of the battery.

[0165] <Preliminary laminate formation step>

[0166] The method disclosed herein includes: (a) sequentially stacking a first electrode active material layer 112 , a solid electrolyte layer 113 , and a second electrode active material layer 114 on both sides of a first current collector layer 111 to form a preliminary stack 100 .

[0167] Regarding the method of stacking the layers, reference can be made to the above description regarding the first method of producing the solid battery 10 of the present disclosure.

[0168] <First Second Current Collector Layer Lamination Step>

[0169] like Figure 6 As illustrated in (a), the method of the present disclosure includes: (b) laminating a first second current collector layer 115 on one main surface of the preliminary laminate 100 .

[0170] The method for laminating the first second current collector layer on one main surface of the preliminary laminate is not particularly limited. For example, when the second current collector layer is a metal foil, a method of placing the metal foil on the second electrode active material layer in the preliminary laminate can be used.

[0171] 〈Insulation component application process〉

[0172] like Figure 6 As illustrated in (b), the method of the present disclosure includes: (c) applying an insulating member 120 to at least a portion of the end surface of the preliminary stack 100 and the portion of the surface of the first second current collector layer 115 on the side contacting the preliminary stack 100 that extends from the preliminary stack.

[0173] The method of applying the insulating member is not particularly limited, and an example thereof includes a method of coating the insulating member.

[0174] The insulating member applied at a desired position can wet and spread on the first and second current collector layers by utilizing surface tension.

[0175] <Second Second Current Collector Layer Lamination Step>

[0176] like Figure 6 As exemplified in (c), the method of the present disclosure includes: (d) laminating a second second current collector layer on the other main surface of the preliminary laminate 100. The method for laminating the second second current collector layer is not particularly limited and can be the same as the method for laminating the first second current collector layer.

[0177] <Electrode stack formation step>

[0178] like Figure 6 As exemplified in (c) and (d), the method of the present disclosure includes: (e) pressing the second second current collector layer 115 to form the electrode stack 110 having the insulating member 120 disposed on the end surface.

[0179] The method of pressing the second current collector layer is not particularly limited, and examples thereof include: Figure 6 As exemplified in (c) and (d), a method of extrusion using an extrusion member is employed.

[0180] There is no particular limitation on the direction of extrusion. For example, the second collector layer may be extruded in the stacking direction of the preliminary stack. Figure 6 As shown in (c), the second current collector layer is compressed by applying a force toward the end surface of the preliminary stack. By compressing the second current collector layer by applying a force toward the end surface of the preliminary stack, it is possible to prevent the insulating member from intruding between the preliminary stack and the second current collector layer. As a result, the thickness of the portion of the solid battery where the insulating member is located can be effectively suppressed.

[0181] like Figure 6 As shown in (d), the insulating member can wet and spread on the second current collector layer by utilizing surface tension, and as a result, the insulating member can be formed into a shape that is concave toward the electrode stack (see Figure 3 and 6 (e)).

[0182] <Insulation Component Solidification Step>

[0183] The method of the present disclosure includes: (f) solidifying the insulating member 120 .

[0184] In the method of the present disclosure, the insulating member may include a thermoplastic resin. In this case, step (c) may further include melting the insulating member including the thermoplastic resin, and step (f) may include solidifying the insulating member including the molten thermoplastic resin.

[0185] Regarding the thermoplastic resin, reference can be made to the above description regarding the solid state battery of the present disclosure.

[0186] When the insulating member comprises a thermoplastic resin, for example, in step (c), an insulating member comprising a pre-melted thermoplastic resin may be used, or the insulating member comprising a thermoplastic resin may be melted after being positioned at a desired position. Furthermore, the thermoplastic resin may be maintained in a molten state in steps (d) and (e).

[0187] The method for solidifying the insulating member containing the molten thermoplastic resin is not particularly limited, and examples thereof include a method of cooling the insulating member. The method for cooling the insulating member is not particularly limited, and examples thereof include a method of air cooling.

[0188] In the method of the present disclosure, the insulating member may contain a curable resin, and in step (f), the insulating member containing the curable resin may be cured to be solidified.

[0189] Regarding the curable resin, reference can be made to the above description related to the solid state battery of the present disclosure.

[0190] The method for curing the insulating member containing a curable resin is not particularly limited. For example, when the curable resin is a photocurable resin, it can be cured by irradiating the curable resin with ultraviolet light, etc. When the curable resin is a thermosetting resin, it can be cured by heating the curable resin.

[0191] Battery Module

[0192] like Figure 7As illustrated in FIG, the battery module 1 of the present disclosure includes the solid battery 10 of the present disclosure. For the solid battery of the present disclosure, reference can be made to the above description related to the solid battery of the present disclosure.

[0193] The solid battery of the present disclosure has a substantially uniform thickness. Therefore, for example, in a battery module of the present disclosure including a plurality of solid batteries of the present disclosure, the effect of improving the volumetric efficiency of the battery becomes more significant.

[0194] There is no particular limitation on the number of solid batteries of the present disclosure in the battery module of the present disclosure, and the number may be at least one. In the battery module of the present disclosure, all batteries may be solid batteries of the present disclosure. Figure 7 , a configuration in which two solid batteries are provided is illustrated, but the number of solid batteries in the battery module of the present disclosure is not limited thereto.

Claims

1. A solid battery comprising an electrode stack, wherein the electrode stack comprises, in order, a first current collector layer, a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, and a second current collector layer. An insulating member is disposed on at least a portion of an end surface of the electrode stack. The second current collector layer extends from an end surface of the electrode stack on which the insulating member is disposed. The insulating member is bonded to the electrode stack and the second current collector layer, and The insulating member extends from an end surface of the electrode stack along the second current collector layer.

2. The solid state battery according to claim 1, wherein The electrode stack includes the first electrode active material layer, the solid electrolyte layer, the second electrode active material layer, and the second current collector layer in this order on both sides of the first current collector layer, and The insulating member is bonded to the electrode stack and the two second current collector layers.

3. The solid state battery according to claim 2, wherein The insulating member has a shape that is recessed toward the electrode stack.

4. The solid state battery according to any one of claims 1 to 3, wherein The first current collector layer is a negative electrode current collector layer, the first electrode active material layer is a negative electrode active material layer, the second electrode active material layer is a positive electrode active material layer, and the second current collector layer is a positive electrode current collector layer.

5. A battery module comprising the solid state battery according to claim 4.

6. The method for producing a solid battery according to any one of claims 1 to 3, comprising the following steps: (a) stacking the first current collector layer, the first electrode active material layer, the solid electrolyte layer, and the second electrode active material layer in this order to form a preliminary stack; (b) applying the insulating member to a portion of the second current collector layer; (c) laminating the second current collector layer on the main surface of the preliminary stack so that the end surface of the preliminary stack and the insulating member coincide with each other in the plane direction of the preliminary stack; (d) pressing the second current collector layer to cause the insulating member to flow toward the end surface of the preliminary stack, thereby forming the electrode stack having the insulating member disposed on at least a portion of the end surface; and (e) solidifying the insulating member.

7. The method according to claim 6, wherein: The insulating member includes a thermoplastic resin, The step (d) further includes melting the thermoplastic resin, causing the insulating member containing the molten thermoplastic resin to flow toward the end surface of the preliminary laminate, and In the step (e), the insulating member containing the molten thermoplastic resin is solidified.

8. The method according to claim 6, wherein: The insulating member is a curable resin, and in the step (e), the insulating member containing the curable resin is cured and solidified.

9. The method for manufacturing a solid battery according to claim 3, comprising the following steps: (a) stacking the first electrode active material layer, the solid electrolyte layer, and the second electrode active material layer in this order on both sides of the first current collector layer to form a preliminary stack; (b) laminating a first second current collector layer on one main surface of the preliminary laminate; (c) applying the insulating member to at least a portion of an end surface of the preliminary laminate and a portion of the first second current collector layer extending from the preliminary laminate; (d) laminating a second second current collector layer on the other main surface of the preliminary laminate; (e) pressing a second second current collector layer to form the electrode stack having the insulating member disposed on an end surface thereof; and (f) solidifying the insulating member.

10. The method according to claim 9, wherein: The insulating member includes a thermoplastic resin, The step (c) further includes melting the insulating member comprising the thermoplastic resin, and In the step (f), the insulating member containing the molten thermoplastic resin is solidified.

11. The method according to claim 9, wherein The insulating member includes a curable resin, and in the step (f), the insulating member including the curable resin is cured and solidified.

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