Solid-state battery and method for producing thereof, and battery module

Abstract

(Problem) The present disclosure provides a solid-state battery with high reliability of insulation by an insulating member. (Solution) The solid-state battery (10) of the present disclosure has an electrode stack (110). The electrode stack 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 the cross-section of the electrode stack. A second current collector layer extends from the cross-section of the electrode stack where the insulating member is disposed, and the insulating member is bonded to the electrode stack and the second current collector layer. The insulating member extends along the second current collector layer from the cross-section of the electrode stack.

Description

Technology Field

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

[0002] In the automotive industry, the development of electric vehicles and hybrid vehicles is underway due to heightened environmental awareness, and the demand for high-voltage secondary batteries is increasing. Meanwhile, in the field of portable electronic devices, with their widespread adoption and development, there is a demand for high-capacity secondary batteries that are small, lightweight, and capable of continuous operation for a long time.

[0003] As a high-voltage, high-capacity battery, for example, a battery is known to have an electrode laminate 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.

[0004] In such a battery, for example, if 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. Additionally, the portion of the current collector layer that extends from the electrode stack is also called a current collection tab. This short circuit is particularly likely to occur when the area of ​​the current collector layer of one electrode is larger than the area of ​​the current collector layer of the other electrode. Therefore, technologies to prevent such short circuits are being developed.

[0005] For example, Patent Document 1 describes a method for manufacturing a stacked all-solid-state battery, comprising: preparing a first stacked body in which a solid electrolyte layer, a first active material layer (electrode active material layer), a first current collector layer having a first current collector tab extending laterally of the stacked all-solid-state battery, a first active material layer, and a solid electrolyte layer are stacked in this order; applying an insulating coating liquid to an end portion of the first stacked body to form an insulating portion (insulating member); and stacking the first stacked body having the insulating portion, a second active material layer, and a second current collector layer having a second current collector tab extending laterally of the stacked all-solid-state battery, such that a second current collector layer having a second current collector tab, a second active material layer, a solid electrolyte layer, a first active material layer, a first current collector layer having a first current collector tab, a first active material layer, a solid electrolyte layer, and a second active material layer A method for manufacturing a stacked all-solid-state battery is disclosed, comprising preparing a battery structure (electrode stack) having a plurality of second stacked bodies stacked in this order, and joining a plurality of second current collection tabs extending from each of the plurality of second current collectors in the battery structure. Prior art literature

[0006] Japanese Patent Publication No. 2018-049696 The problem to be solved

[0007] The present disclosure parties have discovered that when an insulating member is applied to the end surface of a pre-laminated laminate composed of a layer other than the second current collector layer among the electrode laminates, and a second current collector layer is laminated onto the pre-laminated laminate to manufacture the electrode laminate, there are cases where the second current collector layer and the insulating member interfere with each other, and as a result, the reliability of insulation by the insulating member is reduced, such as when the insulating member peels off from the electrode laminate.

[0008] The present disclosure aims to provide a solid-state battery with high reliability of insulation by an insulating member, a method for manufacturing the same, and a battery module having such a solid-state battery. means of solving the problem

[0009] The initiators of this case have discovered that the above problem can be solved by the following means.

[0010] <Mode 1>

[0011] As a solid-state battery having an electrode stack,

[0012] The electrode laminate comprises 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 in this order,

[0013] An insulating member is disposed on at least a portion of the cross-section of the electrode laminate, and

[0014] From the cross-section of the electrode laminate in which the insulating member is disposed, the second current collector layer extends, and

[0015] The above insulating member is bonded to the electrode laminate and the second current collector layer, and also

[0016] A solid-state battery in which the insulating member extends along the second current collector layer from a cross-section of the electrode laminate.

[0017] <Mode 2>

[0018] The electrode laminate comprises, on both sides of the first current collector layer, 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, and also

[0019] A solid-state battery as described in Embodiment 1, wherein the insulating member is bonded to the electrode laminate and two second current collector layers.

[0020] <Mode 3>

[0021] A solid-state battery as described in embodiment 1 or 2, wherein the insulating member has a concave shape toward the electrode laminate.

[0022] <Mode 4>

[0023] A solid-state battery described in any one of embodiments 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.

[0024] <Mode 5>

[0025] A battery module having a solid-state battery as described in Embodiment 4.

[0026] <Mode 6>

[0027] A method for manufacturing a solid-state battery as described in any one of embodiments 1 to 3, comprising the following process:

[0028] (a) Forming a pre-laminated body by 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,

[0029] (b) applying the insulating member to a part of the second current collector layer,

[0030] (c) Laminating the second current collector layer on the main surface of the pre-laminated structure such that the cross section of the pre-laminated structure and the insulating member coincide in the plane direction of the pre-laminated structure.

[0031] (d) pressing the second current collector layer to flow the insulating member into the cross-section of the prefabricated laminate to form the electrode laminate having the insulating member disposed in at least a portion of the cross-section, and

[0032] (e) Solidifying the above insulating member.

[0033] <Mode 7>

[0034] The above insulating member comprises a thermoplastic resin, and

[0035] In the above process (d), the method further comprises melting the thermoplastic resin, flowing the insulating member containing the melted thermoplastic resin onto a cross section of the pre-laminated laminate, and

[0036] In the above process (e), solidifying the insulating member comprising the molten thermoplastic resin,

[0037] The method described in Mode 6.

[0038] <Mode 8>

[0039] The above insulating member is a curable resin, and

[0040] In the above process (e), the insulating member comprising the curable resin is solidified by curing.

[0041] The method described in Mode 6.

[0042] <Mode 9>

[0043] A method for manufacturing a solid-state battery as described in any one of embodiments 1 to 3, comprising the following process:

[0044] (a) Forming a pre-laminated body by 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,

[0045] (b) Laminating the first second current collector layer on one side of the above-mentioned prefabricated laminate,

[0046] (c) Applying the insulating member to a cross section of the pre-laminated structure and to at least a portion of the part extending from the pre-laminated structure in the first second current collector layer,

[0047] (d) Laminating a second second current collector layer on the main surface of the other of the above pre-laminated laminate,

[0048] (e) pressing the second current collector layer to form the electrode laminate having the insulating member disposed on one side, and

[0049] (f) Solidifying the above insulating member.

[0050] <Mode 10>

[0051] The above insulating member comprises a thermoplastic resin, and

[0052] The above process (c) further comprises melting the insulating member containing the thermoplastic resin, and

[0053] In the above process (f), solidifying the insulating member comprising the molten thermoplastic resin,

[0054] The method described in Mode 9.

[0055] <Mode 11>

[0056] The above insulating member comprises a curable resin, and

[0057] In the above process (f), the insulating member comprising the curable resin is solidified by curing.

[0058] The method described in Mode 9. Effects of the invention

[0059] According to the present disclosure, a solid-state battery with high reliability of insulation by an insulating member, a method for manufacturing the same, and a battery module having such a solid-state battery can be provided. Brief explanation of the drawing

[0060] FIG. 1 is a schematic plan view showing an example of a solid-state battery of the present disclosure. FIG. 2 is a schematic cross-sectional view showing an example of an arrangement of insulating members in a solid-state battery of the present disclosure. FIG. 3 is a schematic cross-sectional view showing an example of an arrangement of insulating members in a solid-state battery of the present disclosure. FIG. 4 is a schematic diagram illustrating an example of a method of the present disclosure for manufacturing a solid-state battery. FIG. 5 is a schematic diagram for explaining the positional relationship between a pre-laminated body and an insulating member, etc., in the method of the present disclosure for manufacturing a solid-state battery. FIG. 6 is a schematic diagram illustrating an example of a method of the present disclosure for manufacturing a solid-state battery. FIG. 7 is a schematic perspective view showing an example of a battery module of the present disclosure. Specific details for implementing the invention

[0061] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Furthermore, the present disclosure is not limited to the embodiments described below, and various modifications may be made within the scope of the intent of the disclosure. Also, the dimensional relationships in the drawings do not reflect actual dimensional relationships.

[0062] Solid-state battery

[0063] As illustrated in FIG. 1, the solid-state battery (10) of the present disclosure has an electrode stack (110). As illustrated in FIG. 2 and FIG. 3, the electrode stack 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 in at least a portion of the cross-section of the electrode stack. A second current collector layer extends from the cross-section of the electrode stack where the insulating member is disposed, and the insulating member is bonded to the electrode stack and the second current collector layer. The insulating member extends along the second current collector layer from the cross-section of the electrode stack. FIG. 2 and FIG. 3 are enlarged schematic cross-sectional views of a portion of the insulating member (120) of the solid-state battery (10) of the present disclosure.

[0064] The present disclosure parties have discovered that the reliability of insulation by the insulating member is increased by configuring the insulating member to be bonded to the electrode laminate and the second current collector layer, and also extending the insulating member along the second current collector layer from the cross-section of the electrode laminate. The reason for this is thought to be that, since the insulating member is bonded to the electrode laminate and the second current collector layer, the insulating member does not easily detach from the electrode laminate.

[0065] In addition, it is thought that since the insulating member extends along the second current collector layer from the cross-section of the electrode laminate, the insulating member can reinforce the second current collector layer and prevent it from tearing easily.

[0066] As exemplified in FIGS. 2 and 3, the electrode laminate may have a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, and a second current collector layer in that order on both sides of the first current collector layer, and an insulating member may be bonded to the electrode laminate and the two second current collector layers. By configuring it in this way, the detachment of the insulating member from the electrode laminate can be suppressed more effectively, and thus the reliability of insulation by the insulating member can be increased.

[0067] With respect to the present disclosure, the term "solid-state battery" refers to a battery that uses at least a solid electrolyte as the electrolyte, and thus, the solid-state battery may use a combination of a solid electrolyte and a liquid electrolyte as the electrolyte. Furthermore, the solid-state battery of the present disclosure may be an all-solid-state battery, that is, a battery that uses only a solid electrolyte as the electrolyte.

[0068] The solid-state battery of the present disclosure may be a lithium-ion secondary battery. Examples of applications for the battery include power sources for vehicles such as hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), electric vehicles (BEV), gasoline vehicles, and diesel vehicles. In particular, it is preferable to use it as a power source for driving hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), or electric vehicles (BEV). Furthermore, the battery of the present disclosure may be used as a power source for mobile bodies other than vehicles (e.g., railways, ships, aircraft) and as a power source for electrical products such as information processing devices.

[0069] Hereinafter, the elements constituting the solid-state battery of the present disclosure will be described.

[0070] Electrode laminate

[0071] The solid-state battery (10) of the present disclosure has an electrode stack (110). The electrode stack functions as a power generation element of the battery. As illustrated in FIGS. 2 and 3, the electrode stack may have 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. That is, the electrode stack may have 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 in this order.

[0072] The first current collector layer can be a negative electrode current collector layer, the first electrode active material layer can be a negative electrode active material layer, the second electrode active material layer can be a positive electrode active material layer, and the second current collector layer can also be a positive electrode current collector layer. That is, the electrode laminate may have 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.

[0073] The shape of the electrode laminate is not particularly limited, but it may, for example, have a top surface, a bottom surface facing the top surface, and four side surfaces connecting the top surface and the bottom surface. The shape of the top surface is not particularly limited, but examples include squares such as squares, rectangles, rhombuses, trapezoids, and parallelograms. In addition, the shape of the top surface may be a polygon other than a square, or a shape having curves such as a circle. The shape of the bottom surface may be the same as the shape of the top surface. The shape of the side surfaces is not particularly limited, but examples include squares such as squares, rectangles, rhombuses, trapezoids, and parallelograms.

[0074] The size of the electrode stack is not particularly limited and can be appropriately designed according to, for example, the desired characteristics of the battery.

[0075] Hereinafter, each component capable of constituting an electrode stack related to the present disclosure will be described.

[0076] In addition, to facilitate understanding of the present disclosure, each component related to the electrode stack of a solid-state lithium-ion secondary battery is described as an example, but the solid-state battery of the present disclosure is not limited to a lithium-ion secondary battery.

[0077] (The entire floor of the house)

[0078] The conductive material used in the positive electrode current collector layer is not particularly limited and can be, for example, SUS, aluminum, copper, nickel, iron, titanium, carbon, etc.

[0079] The shape of the positive electrode current collector layer is not particularly limited and may include, for example, thin, plate, or mesh forms. Among these, a thin form is preferred.

[0080] The positive electrode current collector layer may extend from a cross-section of the electrode laminate, and a plurality of positive electrode current collector layers may be bonded in the extended portion.

[0081] (Polar active material layer)

[0082] The positive electrode active material layer comprises at least a positive electrode active material and, preferably, further comprises a solid electrolyte as described below. In addition, depending on the intended use or purpose, it may include additives used in the positive electrode active material layer of a solid-state battery, such as, for example, a conductivity aid or a binder.

[0083] The material for the positive electrode active material is not particularly limited. For example, the positive electrode active material may be lithium cobaltate (LiCoO2), lithium nickelate (LiNiO2), lithium manganate (LiMn2O4), Li 1.5 Co 1 / 3 Ni 1 / 3 Mn 1 / 3 O2, LiCo 1 / 3 Ni 1 / 3 Mn 1 / 3 O2, Li 1+x Mn 2-x-y M y It may be a heterogeneous element-substituted Li-Mn spinel with a composition represented by O4 (M is one or more metallic elements selected from Al, Mg, Co, Fe, Ni and Zn).

[0084] The conductivity aid is not particularly limited. For example, the conductivity aid can be carbon materials such as VGCF (Vapor Grown Carbon Fiber) and carbon nanofibers, and metal materials.

[0085] The binder is not particularly limited. For example, the binder may be a material such as polyvinylidene fluoride (PVdF), carboxymethylcellulose (CMC), butadiene rubber (BR), styrene-butadiene rubber (SBR), or a combination thereof.

[0086] (Solid electrolyte layer)

[0087] The solid electrolyte layer comprises at least a solid electrolyte. As the solid electrolyte, no specific material may be used, and any material suitable for use as a solid electrolyte for a solid-state battery may be used. For example, the solid electrolyte may be a sulfide solid electrolyte, an oxide solid electrolyte, or a polymer electrolyte.

[0088] Examples of sulfide solid electrolytes include, but are not limited to, sulfide-based amorphous solid electrolytes, sulfide-based crystalline solid electrolytes, and agirodite-type solid electrolytes. Specific examples of sulfide solid electrolytes include the Li2S-P2S5 system (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 may be cited, but are not limited to these.

[0089] As an example of an oxide solid electrolyte, 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 xExamples include (LiPON), but are not limited to these.

[0090] Examples of polymer electrolytes include polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof, but are not limited to these.

[0091] The solid electrolyte may be glass or crystallized glass (glass ceramic). In addition, the solid electrolyte layer may include, in addition to the solid electrolyte described above, a conductivity aid, a binder, etc., as needed. For the conductivity aid and binder, refer to the description regarding the positive electrode active material layer.

[0092] (Negative electrode active material layer)

[0093] The negative electrode active material layer comprises at least a negative electrode active material and, preferably, further comprises the solid electrolyte described above. In addition, depending on the application or purpose of use, it may include additives used in the negative electrode active material layer of a solid-state battery, such as, for example, conductivity aids and binders.

[0094] As a material for the negative electrode active material, it is not particularly limited, but it is desirable that it be capable of absorbing and releasing metal ions such as lithium ions. For example, the negative electrode active material may 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.

[0095] The oxide-based negative electrode active material is not particularly limited, and examples include lithium titanate (LTO) particles.

[0096] As an alloy-based negative electrode active material, it is not particularly limited, and examples include Si alloy-based negative electrode active materials or 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 include elements other than silicon, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, etc. Examples of Sn alloy-based negative electrode active materials include tin, tin oxide, tin nitride, or solid solutions thereof. In addition, Sn alloy-based negative electrode active materials may include elements other than tin, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, etc.

[0097] Carbon materials are not particularly limited and, for example, hard carbon, soft carbon, graphite, etc.

[0098] Regarding the solid electrolyte used in the negative electrode active material layer, one may refer to the above description regarding the solid electrolyte layer, and regarding the conductivity aid and binder, one may refer to the above description regarding the positive electrode active material layer.

[0099] (Buguk entire house floor)

[0100] The conductive material used in the negative electrode current collector layer is not particularly limited and, for example, may be SUS, aluminum, copper, nickel, iron, titanium, carbon, etc., but is not limited to these.

[0101] The shape of the negative electrode current collector layer is not particularly limited and may include, for example, thin, plate, or mesh forms. Among these, a thin form is preferred.

[0102] The negative electrode current collector layer may extend from a cross-section of the electrode laminate, and a plurality of negative electrode current collector layers may be bonded in the extended portion.

[0103] <Insulating Member>

[0104] As illustrated in FIGS. 2 and 3, the insulating member (120) may have a shape that is concave toward the electrode laminate (110). By configuring it in this way, compared to the case where the insulating member has a shape that is not concave toward the electrode laminate, the following ability of the insulating member to the curvature of the second current collector layer can be increased, and thus the reliability of insulation by the insulating member can be increased. In addition, the amount of material used for the insulating member can be reduced.

[0105] When the insulating member has a concave shape facing the electrode laminate, the length L1 of the portion of the insulating member in contact with the second current collector layer may be 100 μm or more, 300 μm or more, 500 μm or more, or 1 mm or more, and may be 3 mm or less, 2 mm or less, or 1 mm or less, or 500 μm or less. By configuring it in this way, the second current collector layer can be adequately reinforced. In addition, the insulating member can be positioned without excessively impairing the volumetric efficiency in the plane direction of the electrode laminate, that is, in the x-direction in FIGS. 2 and 3.

[0106] When the insulating member has a concave shape toward the electrode laminate, the length L2 from the cross-section of the electrode laminate to the apex of the concave portion may be 10 μm or more, 20 μm or more, 30 μm or more, 50 μm or more, or 100 μm or more, and may be 500 μm or less, 300 μm or less, or 100 μm or less. By configuring it in this way, insulation by the insulating member can be secured, and the amount of material used for the insulating member can also be reduced. In addition, in FIG. 2, the concave portion may be a concave portion formed near the center of the stacking direction of the electrode laminate and two concave portions formed along the second current collector layer. Also, in FIG. 2, an embodiment in which the length L2 of each concave portion is equal is illustrated, but the length L2 of each concave portion may be different.

[0107] The insulating member (120) may contain a thermoplastic resin and may be a thermoplastic resin. The thermoplastic resin is not particularly limited and may be non-reactive or reactive. Non-reactive thermoplastic resins are not particularly limited and examples include ethylene vinyl acetate (EVA)-based, synthetic rubber-based, olefin-based, polyamide-based, or polyester-based resins such as polyethylene terephthalate (PET). Reactive resins are not particularly limited and examples include urethane-based resins.

[0108] The insulating member (120) may contain a curable resin and may be a curable resin. The curable resin is not particularly limited, and thermosetting resin or photocurable resin is an example. Acrylic or epoxy resins are examples of these resins.

[0109] The shape of the insulating member (120) is not particularly limited, but as described above, it may have a shape that is concave toward the electrode laminate (110).

[0110] The size of the insulating member (120) is not particularly limited, but can be appropriately designed considering the volumetric efficiency of the battery, etc.

[0111] <Laminate Film>

[0112] The solid-state battery (10) of the present disclosure may have a laminate film (130). The laminate film may accommodate an electrode stack. Specifically, the laminate film may accommodate the electrode stack by winding the electrode stack. In addition, the laminate film may be composed of a first film and a second film, and in this case, the electrode stack may be accommodated by the first and second films by sandwiching it between the upper and lower parts of the electrode stack in the stacking direction.

[0113] The laminate film may have a sealant resin layer, a metal layer, and a protective resin layer in this order along the thickness direction. For example, olefin resins such as polypropylene (PP) and polyethylene (PE) may be used as materials for the sealant resin layer. For example, aluminum, aluminum alloys, and stainless steel may be used as materials for the metal layer. For example, polyethylene terephthalate (PET) and nylon may be used as materials for the protective resin layer.

[0114] Each layer constituting the laminate film and the thickness of the laminate film are not particularly limited. The thickness of the sealant resin layer is, for example, 40 μm or more and 100 μm or less. The thickness of the metal layer is, for example, 30 μm or more and 60 μm or less. The thickness of the protective resin layer is, for example, 20 μm or more and 60 μm or less. The thickness of the laminate film is, for example, 80 μm or more and 250 μm or less.

[0115] <Collection terminal>

[0116] The solid-state battery (10) of the present disclosure may additionally be provided with a current collection terminal (140). The current collection terminal may be electrically connected to a current collection portion of the electrode stack. The material of the current collection terminal is not particularly limited as long as it has a current collection function. As exemplified in FIG. 1, the positive electrode current collection terminal and the negative electrode current collection terminal may be disposed on opposite pairs of side portions of the electrode stack. The positive electrode current collection terminal and the negative electrode current collection terminal may be disposed spaced apart from each other on one side portion of the electrode stack.

[0117] The shape and size of the current collection terminals are not specifically limited.

[0118] When the solid-state battery of the present disclosure has a current collection terminal, the laminate film may accommodate an electrode stack together with the current collection terminal. Specifically, the laminate film may wrap the electrode stack and the current collection terminal to accommodate the electrode stack together with the current collection terminal. In addition, the laminate film may be composed of a first film and a second film, and in this case, the electrode stack and the current collection terminal may be sandwiched between the upper and lower sides of the electrode stack in the stacking direction by the first and second films to accommodate the electrode stack together with the current collection terminal.

[0119] Method for manufacturing solid-state batteries

[0120] Hereinafter, the first method of the present disclosure for manufacturing a solid-state battery (10) will be described.

[0121] As illustrated in FIG. 4, the method of the present disclosure for manufacturing a solid-state battery (10) comprises the following steps: (a) forming a pre-laminated body (100) by 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) in this order; (b) applying an insulating member (120) to a part of the second current collector layer (115); (c) stacking the second current collector layer (115) on the main surface of the pre-laminated body (100) such that the cross-section of the electrode laminate (110) and the insulating member (120) coincide in the plane direction of the pre-laminated body (100); and (d) pressing the second current collector layer (115) to apply the insulating member (120) to the cross-section of the pre-laminated body (100). (e) forming an electrode laminate (110) in which an insulating member (120) is disposed on at least a portion of the cross-section by flowing, and solidifying the insulating member (120).

[0122] That is, according to the method of the present disclosure, an insulating member is applied to connect a cross section of an electrode laminate with a second current collector layer. In addition, the method of the present disclosure includes solidifying such an insulating member. By doing so, the adhesion of the insulating member to the electrode laminate is strengthened, and the insulating member can be prevented from easily peeling off from the electrode laminate. As a result, the reliability of insulation by the insulating member can be improved.

[0123] In addition, the method of the present disclosure includes applying pressure to the second current collector layer to flow an insulating member into the cross section of the pre-laminated structure. Accordingly, the thickness of the solid-state battery manufactured by the method of the present disclosure becomes approximately uniform, and as a result, the volumetric efficiency of the battery is improved.

[0124] In addition, regarding the present disclosure, the term "preliminary laminate" means a laminate having 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 having a second current collector layer laminated to form an electrode laminate.

[0125] <Preliminary Laminate Formation Process>

[0126] The method of the present disclosure comprises (a) forming a pre-laminated body (100) by 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) in this order.

[0127] The method of stacking each layer is not particularly limited, and examples include dry molding such as powder pressing and wet molding using a slurry. For example, in the case of wet molding, a first electrode composite slurry capable of forming a first electrode active material layer is first applied to one side of the first current collector layer and dried, thereby allowing the first electrode active material layer to be stacked on the first current collector layer. A solid electrolyte layer can be stacked on the first electrode active material layer in the same manner by using a solid electrolyte slurry. A second electrode active material layer can be stacked on the solid electrolyte layer in the same manner by using a second electrode composite slurry.

[0128] The height H of the prefabricated laminate shown in Fig. 5, that is, the length in the lamination direction, is not particularly limited, for example, it may be 50 μm or more, 100 μm or more, or 150 μm or more, or 500 μm or less, 300 μm or less, 200 μm or less, or 150 μm or less.

[0129] <Insulating Member Application Process>

[0130] As illustrated in FIG. 4(a), the method of the present disclosure includes (b) applying an insulating member (120) to a portion of the second current collector layer (115).

[0131] In process (b), for "some", the length L3 in the x-direction (plane direction of the electrode laminate) of the insulating member can be defined (see FIG. 5). For example, this length L3 may be 100 μm or more, 500 μm or more, 1 mm or more, or 2 mm or more, and may be 5 mm or less, 4 mm or less, 3 mm or less, or 2 mm or less.

[0132] The amount of insulating material applied to the second current collector layer can be defined by the thickness T of the insulating material (length in the stacking direction of the electrode laminate) (see FIG. 5). For example, this thickness T can be 10 μm or more, 50 μm or more, 75 μm or more, or 100 μm or more, and 300 μm or less, 200 μm or less, 150 μm or less, or 100 μm or less.

[0133] The method of applying the insulating material is not particularly limited, and for example, a method of applying the insulating material can be cited.

[0134] <Second Current Collector Layer Lamination Process>

[0135] As illustrated in FIG. 4(b), the method of the present disclosure comprises (c) laminating a second current collector layer (115) on the main surface of a prefabricated laminate (100) such that the cross section of the prefabricated laminate (100) and the insulating member (120) coincide in the plane direction of the prefabricated laminate (100).

[0136] The location where the second current collector layer is laminated can be defined as the length L1 of the portion extending from the cross-section of the electrode laminate among the insulating members. As described above, for example, this length L1 may be 100 μm or more, 300 μm or more, 500 μm or more, or 1 mm or more, and may be 3 mm or less, 2 mm or less, 1 mm or less, or 500 μm or less.

[0137] For thickness T, length L1, and height H, it is sufficient if the following relationship is satisfied:

[0138] T (㎛) × L1 (㎜) × 1000 > 10 (㎛) × H (㎛) / 2.

[0139] By satisfying this relationship, insulation by the insulating member can be secured without substantially increasing the thickness of the battery in the part where the insulating member is applied. In addition, by satisfying this relationship, it is easy to make the insulating member concave toward the electrode laminate (see FIG. 2 and 4(c)).

[0140] <Electrode Stack Formation Process>

[0141] As illustrated in FIG. 4(b) and FIG. 4(c), the method of the present disclosure comprises (d) pressing the second current collector layer (115) to flow an insulating member (120) onto a cross section of the prefabricated laminate (100) to form an electrode laminate (110) having an insulating member (120) disposed on a cross section.

[0142] The method of pressurizing the second current collector layer is not particularly limited, but, for example, as exemplified in FIG. 4(b), a method of pressurizing using a pressurizing member may be used.

[0143] The direction of application of pressure is not specifically limited. For example, the second current collector layer may be applied in the stacking direction of the pre-laminated laminate, and in particular, the second current collector layer may be applied such that a force is applied toward the cross-section of the pre-laminated laminate. By applying the second current collector layer such that a force is applied toward the cross-section of the pre-laminated laminate, the insulating member can be effectively moved toward the cross-section of the pre-laminated laminate.

[0144] <Insulation Member Solidification Process>

[0145] The method of the present disclosure includes (e) solidifying an insulating member (120).

[0146] In the method of the present disclosure, the insulating member may comprise a thermoplastic resin, and in this case, the insulating member comprising the molten thermoplastic resin may additionally comprise melting the thermoplastic resin in process (d), and the insulating member comprising the molten thermoplastic resin may be flowed into the cross section of a pre-laminated body, and the insulating member comprising the molten thermoplastic resin may be solidified in process (e).

[0147] Regarding thermoplastic resins, reference may be made to the above description concerning solid-state batteries of the present disclosure.

[0148] In the case where the insulating member contains a thermoplastic resin, the second current collector layer can be heated to melt the thermoplastic resin, and the second current collector layer can be pressed to allow the insulating member containing the melted thermoplastic resin to flow into the cross-section of the pre-laminated laminate. In particular, for example, the heating and pressing of the second current collector layer can be performed as a single unit using a heat bar, etc.

[0149] A method for solidifying an insulating member containing a molten thermoplastic resin is not particularly limited, but, for example, a method of cooling the insulating member may be used. A method for cooling the insulating member is not particularly limited, but, for example, a method of air cooling may be used.

[0150] In the method of the present disclosure, the insulating member may be a curable resin, and in this case, in process (e), the insulating member containing the curable resin may be solidified by curing.

[0151] Regarding curable resins, reference may be made to the above description relating to solid-state batteries of the present disclosure.

[0152] The method for curing an 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 rays, etc. If the curable resin is a thermosetting resin, it can be cured by heating the curable resin.

[0153] Hereinafter, a second method of the present disclosure for manufacturing a solid-state battery (10) will be described.

[0154] As illustrated in FIG. 6, the method of the present disclosure for manufacturing a solid-state battery comprises the following steps: (a) forming a pre-laminated body (100) by stacking a first electrode active material layer (112), a solid electrolyte layer (113), and a second electrode active material layer (114) in this order on both sides of a first current collector layer (111); (b) stacking a first second current collector layer (115) on a main surface of one side of the pre-laminated body (100); (c) applying an insulating member (120) to a cross section of the pre-laminated body (100) and to at least a portion of the first second current collector layer (115) that extends from the pre-laminated body (100); and (d) stacking a second second current collector layer (115) on the main surface of the other side of the pre-laminated body (100). (e) pressing the second second current collector layer (115) to form an electrode laminate (110) having an insulating member (120) disposed on one side, and (f) solidifying the insulating member (120).

[0155] That is, the method of the present disclosure includes solidifying an insulating member applied to connect a cross section of an electrode laminate and a second current collector layer. By doing so, the adhesion of the insulating member to the electrode laminate is strengthened, so that the insulating member is not easily peeled off from the electrode laminate. As a result, the reliability of insulation by the insulating member can be improved.

[0156] In addition, the method of the present disclosure includes pressing a second current collector layer to deform an insulating member, thereby forming an electrode laminate in which an insulating member is disposed on one side. Accordingly, the thickness of the solid-state battery manufactured by the method of the present disclosure becomes approximately uniform, and as a result, the volumetric efficiency of the battery is improved.

[0157] <Preliminary Laminate Formation Process>

[0158] The method of the present disclosure comprises (a) forming a pre-laminated body (100) by stacking a first electrode active material layer (112), a solid electrolyte layer (113), and a second electrode active material layer (114) in this order on both sides of a first current collector layer (111).

[0159] For the method of stacking each layer, one may refer to the above description regarding the first method of the present disclosure for manufacturing a solid-state battery (10).

[0160] <1st Second Current Collector Layer Lamination Process>

[0161] As illustrated in FIG. 6(a), the method of the present disclosure comprises (b) laminating a first second current collector layer (115) on one side of a prefabricated laminate (100).

[0162] The method of laminating a first second current collector layer on one side of a prefabricated laminate is not particularly limited. For example, if the second current collector layer is a metal foil, a method of placing the metal foil on the second electrode active material layer of the prefabricated laminate may be used.

[0163] <Insulating Member Application Process>

[0164] As illustrated in FIG. 6(b), the method of the present disclosure comprises applying an insulating member (120) to at least a portion of the portion extending from the pre-laminated body, which is in contact with the pre-laminated body (100), in (c) a cross section of the pre-laminated body (100) and a first second current collector layer (115).

[0165] The method of applying the insulating material is not particularly limited, and for example, a method of applying the insulating material may be used.

[0166] The insulating member applied at the desired location can diffuse while wetting onto the first second current collector layer by surface tension.

[0167] <2nd Second Current Collector Layer Lamination Process>

[0168] As illustrated in FIG. 6(c), the method of the present disclosure comprises (d) laminating a second second current collector layer on the main surface of the other of the prefabricated laminate (100). The method of laminating the second second current collector layer is not particularly limited, but may be the same as the method of laminating the first second current collector layer.

[0169] <Electrode Stack Formation Process>

[0170] As illustrated in FIG. 6(c) and FIG. 6(d), the method of the present disclosure comprises (e) pressing a second second current collector layer (115) to form an electrode laminate (110) having an insulating member (120) disposed on one side.

[0171] The method of pressurizing the second current collector layer is not particularly limited, but, for example, as illustrated in FIG. 6(c) and FIG. 6(d), a method of pressurizing using a pressurizing member may be used.

[0172] The direction of application of pressure is not particularly limited. For example, the second current collector layer may be applied in the stacking direction of the pre-laminated structure, and in particular, as exemplified in FIG. 6(c), the second current collector layer may be applied such that a force is applied toward the cross-section of the pre-laminated structure. By applying the second current collector layer such that a force is applied toward the cross-section of the pre-laminated structure, it is difficult for the insulating member to penetrate between the pre-laminated structure and the second current collector layer. As a result, the increase in the thickness of the portion where the insulating member is placed in the solid-state battery can be effectively suppressed.

[0173] As exemplified in FIG. 6(d), the insulating member can be diffused onto the second current collector layer while wetting it due to surface tension, and as a result, the insulating member can be formed into a concave shape toward the electrode laminate (see FIG. 3 and FIG. 6(e)).

[0174] <Insulation Member Solidification Process>

[0175] The method of the present disclosure includes (f) solidifying an insulating member (120).

[0176] In the method of the present disclosure, the insulating member may comprise a thermoplastic resin, and in this case, the insulating member comprising the thermoplastic resin may further comprise melting in process (c), and the insulating member comprising the melted thermoplastic resin may be solidified in process (f).

[0177] Regarding thermoplastic resins, reference may be made to the above description concerning solid-state batteries of the present disclosure.

[0178] In the case where the insulating member contains a thermoplastic resin, for example, in process (c), an insulating member containing a thermoplastic resin that has been pre-melted may be applied, or the insulating member containing the thermoplastic resin may be melted after being placed at a desired location. Also, in processes (d) and (e), the molten state of the thermoplastic resin must be maintained.

[0179] A method for solidifying an insulating member containing a molten thermoplastic resin is not particularly limited, but, for example, a method of cooling the insulating member may be used. A method for cooling the insulating member is not particularly limited, but, for example, a method of air cooling may be used.

[0180] In the method of the present disclosure, the insulating member may include a curable resin, and in process (f), the insulating member including the curable resin may be solidified by curing.

[0181] Regarding curable resins, reference may be made to the above description relating to solid-state batteries of the present disclosure.

[0182] The method for curing an 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 rays, etc. If the curable resin is a thermosetting resin, it can be cured by heating the curable resin.

[0183] Battery Module

[0184] As illustrated in FIG. 7, the battery module (1) of the present disclosure has a solid-state battery (10) of the present disclosure. For the solid-state battery of the present disclosure, one may refer to the above description regarding the solid-state battery of the present disclosure.

[0185] Since the thickness of the solid-state battery of the present disclosure is approximately uniform, for example, in a battery module of the present disclosure having a plurality of solid-state batteries of the present disclosure, the effect of improving the volumetric efficiency of the battery becomes even more pronounced.

[0186] The number of solid-state batteries in the battery module of the present disclosure is not particularly limited and at least one is sufficient. In the battery module of the present disclosure, all batteries may be solid-state batteries of the present disclosure. Also, although an embodiment in which the number of solid-state batteries is two is shown in FIG. 7, the number of solid-state batteries in the battery module of the present disclosure is not limited to this. Explanation of the symbols

[0187] 1 : Battery module 10: Solid-state battery 100 : Prefabricated laminate 110: Electrode laminate 111: First entire floor 112: First electrode active material layer 113: Solid electrolyte layer 114: Second electrode active material layer 115 : 2nd entire floor 120 : Insulating member 130 : Laminate film 140 : Current collection terminal

Claims

Claim 1 A solid-state battery having an electrode stack, wherein the electrode stack has, in this 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 a first current collector layer, an insulating member is disposed on at least a portion of the cross-section of the electrode stack, and the second current collector layer extends from the cross-section of the electrode stack where the insulating member is disposed, and the insulating member is bonded to the electrode stack and two of the second current collector layers, and the insulating member extends along the second current collector layer from the cross-section of the electrode stack. Claim 2 delete Claim 3 A solid-state battery according to claim 1, wherein the insulating member has a concave shape toward the electrode laminate. Claim 4 A solid-state battery according to claim 1 or 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. Claim 5 A battery module having a solid-state battery as described in claim 4. Claim 6 A method for manufacturing a solid-state battery according to claim 1 or 3, comprising the following processes: (a) forming a pre-laminated body by 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; (b) applying the insulating member to a part of the second current collector layer; (c) stacking the second current collector layer on the main surface of the pre-laminated body such that the cross-section of the pre-laminated body and the insulating member coincide in the plane direction of the pre-laminated body; (d) pressing the second current collector layer to flow the insulating member onto the cross-section of the pre-laminated body, thereby forming the electrode laminate in which the insulating member is disposed on at least a part of the cross-section; and (e) solidifying the insulating member. Claim 7 A method according to claim 6, wherein the insulating member comprises a thermoplastic resin, and further comprises melting the thermoplastic resin in process (d), flowing the insulating member comprising the melted thermoplastic resin into a cross section of the pre-laminated body, and solidifying the insulating member comprising the melted thermoplastic resin in process (e). Claim 8 A method according to claim 6, wherein the insulating member is a curable resin, and in the process (e), the insulating member comprising the curable resin is solidified by curing. Claim 9 A method for manufacturing a solid-state battery as described in claim 3, comprising the following processes: (a) forming a pre-laminated body by 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; (b) stacking the first second current collector layer on the main surface of one side of the pre-laminated body; (c) applying the insulating member to the cross section of the pre-laminated body and at least a portion of the first second current collector layer extending from the pre-laminated body; (d) stacking the second second current collector layer on the main surface of the other side of the pre-laminated body; (e) pressing the second second current collector layer to form the electrode laminate having the insulating member disposed on its cross section; and (f) solidifying the insulating member. Claim 10 A method according to claim 9, wherein the insulating member comprises a thermoplastic resin, wherein in process (c), the insulating member comprising the thermoplastic resin is further melted, and wherein in process (f), the insulating member comprising the melted thermoplastic resin is solidified. Claim 11 A method according to claim 9, wherein the insulating member comprises a curable resin, and in the process (f), the insulating member comprising the curable resin is solidified by curing.

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