Solid-state battery and method for producing the same, and battery module

Abstract

To provide a solid-state battery with highly reliable insulation by an insulating member.SOLUTION: A solid-state battery 10 of the present disclosure includes an electrode stack 110. The electrode stack includes 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 part of the edge face of the electrode stack, The second current collector layer extends from the edge face of the electrode stack on which the insulating member is disposed, and the insulating member is joined with the electrode stack and the second current collector layer. The insulating member extends from the edge face of the electrode stack along the second current collector layer.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a solid-state battery, a manufacturing method thereof, and a battery module. [Background technology]

[0002] In the automotive industry, growing environmental awareness has led to the development of electric vehicles, hybrid vehicles, etc., and this has led to a growing demand for high-voltage secondary batteries. Meanwhile, in the field of portable electronic devices, the widespread adoption and development of these devices has led to a demand for small, lightweight, high-capacity secondary batteries capable of long periods of continuous operation.

[0003] Known high-voltage, high-capacity batteries include, for example, batteries that include an electrode stack having, 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.

[0004] In such batteries, for example, if the current collector layer of one electrode extends beyond the electrode stack, it may come into contact with the current collector layer and / or active material layer of the other electrode, resulting in a short circuit. The portion of the current collector layer extending beyond the electrode stack is also called a current collector 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 have been developed.

[0005] For example, Patent Document 1 discloses a method for manufacturing a stacked all-solid-state battery, which includes 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 to the side 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 of the first stacked body to form an insulating part (insulating member); and assembling the first stacked body with the insulating part formed thereon, a second active material layer, and a second current collector tab extending to the side of the stacked all-solid-state battery. and a second current collector layer having a second current collecting tab, to prepare a battery structure (electrode laminate) having a plurality of second laminates, each of which is formed by laminating a second current collector layer having a second current collecting tab, a second active material layer, a solid electrolyte layer, a first active material layer, a first current collector layer having a first current collecting tab, a first active material layer, a solid electrolyte layer, and a second active material layer in this order; and joining a plurality of second current collecting tabs extending from the plurality of second current collectors in the battery structure. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-049696 Summary of the Invention [Problem to be solved by the invention]

[0007] The present inventors have found that when an electrode laminate is manufactured by applying an insulating member to an end face of a preliminary laminate composed of layers other than the second current collector layer of the electrode laminate, and then laminating the second current collector layer on the preliminary laminate, the second current collector layer and the insulating member may interfere with each other, resulting in a decrease in the reliability of insulation provided by the insulating member, such as the insulating member peeling off from the electrode laminate.

[0008] An object of the present disclosure is to provide a solid-state battery that provides highly reliable insulation from an insulating member, a method for manufacturing the same, and a battery module that includes such a solid-state battery. [Means for solving the problem]

[0009] The present inventors have found that the above problems can be solved by the following means. <Aspect 1> A solid-state battery having an electrode stack, the electrode laminate has, in this 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 part 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 the end surface of the electrode stack along the second current collector layer. solid state battery. <Aspect 2> the electrode laminate has 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; the insulating member is bonded to the electrode stack and the two second current collector layers; 2. The solid-state battery of embodiment 1. <Aspect 3> 3. The solid-state battery according to claim 1, wherein the insulating member has a shape recessed toward the electrode stack. <Aspect 4> The solid state battery of any one of aspects 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. <Aspect 5> A battery module having the solid-state battery according to embodiment 4. <Aspect 6> A method for producing the solid state battery according to any one of aspects 1 to 3, comprising the steps of: (a) laminating 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 laminate; (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 pre-laminate so that the end face of the pre-laminate and the insulating member coincide with each other in the surface direction of the pre-laminate; (d) pressing the second current collector layer to cause the insulating member to flow onto the end surface of the preliminary laminate, thereby forming the electrode laminate in which the insulating member is disposed on at least a part of the end surface; and (e) solidifying the insulating material; <Aspect 7> the insulating member contains a thermoplastic resin, The step (d) further includes melting the thermoplastic resin, and causing the insulating member containing the molten thermoplastic resin to flow onto the end surface of the pre-laminate; In the step (e), the insulating member containing the molten thermoplastic resin is solidified. The method of embodiment 6. <Aspect 8> the insulating member is a curable resin, and In the step (e), the insulating member containing the curable resin is hardened to be solidified. The method of embodiment 6. <Aspect 9> A method for producing the solid state battery according to any one of aspects 1 to 3, comprising the steps of: (a) forming a preliminary laminate by laminating 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) laminating a first of the second current collector layers on one main surface of the preliminary laminate; (c) applying the insulating member to an end face of the pre-laminate and at least a part of a portion of a first second current collector layer extending from the pre-laminate; (d) laminating a second current collector layer on the other main surface of the preliminary laminate; (e) pressing the second current collector layer to form the electrode stack having the insulating member disposed on an end surface thereof; and (f) solidifying the insulating material; <Aspect 10> the insulating member contains a thermoplastic resin, 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. 10. The method of embodiment 9. <Aspect 11> the insulating member includes a curable resin; and In the step (f), the insulating member containing the curable resin is hardened to be solidified. 10. The method of embodiment 9. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a solid-state battery in which the insulating member provides highly reliable insulation, a method for manufacturing the same, and a battery module having such a solid-state battery. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic plan view showing an example of a solid state battery according to the present disclosure. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of an arrangement of insulating members in the solid state battery of the present disclosure. [Figure 3] FIG. 3 is a schematic cross-sectional view showing an example of an arrangement of insulating members in the solid state battery of the present disclosure. [Figure 4] FIG. 4 is a schematic diagram illustrating an example of a method of the present disclosure for producing a solid-state battery. [Figure 5] FIG. 5 is a schematic diagram for explaining the positional relationship between the pre-laminate and the insulating member in the method of the present disclosure for producing a solid state battery. [Figure 6] FIG. 6 is a schematic diagram illustrating an example of a method of the present disclosure for producing a solid-state battery. [Figure 7] FIG. 7 is a schematic perspective view showing an example of a battery module according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the present disclosure. Furthermore, the dimensional relationships in the drawings do not reflect the actual dimensional relationships.

[0013] 《Solid-state battery》 As illustrated in FIG. 1, a solid state battery 10 according to the present disclosure includes an electrode stack 110. As illustrated in FIGS. 2 and 3, the electrode stack includes 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 end surface of the electrode stack. A second current collector layer extends from the end surface of the electrode stack on which 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 from the end surface of the electrode stack along the second current collector layer. FIGS. 2 and 3 are enlarged schematic cross-sectional views of the insulating member 120 of the solid state battery 10 according to the present disclosure.

[0014] The present inventors have found that the reliability of insulation provided 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 to extend from the end face of the electrode laminate along the second current collector layer. This is thought to be because, since the insulating member is bonded to the electrode laminate and the second current collector layer, the insulating member is less likely to fall off from the electrode laminate.

[0015] Furthermore, it is believed that the insulating member extending from the end face of the electrode laminate along the second current collector layer reinforces the second current collector layer, making it less likely to break.

[0016] 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 a first current collector layer, and an 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 from the electrode stack, thereby increasing the reliability of insulation provided by the insulating member.

[0017] In the context of the present disclosure, a "solid-state battery" refers to a battery that uses at least a solid electrolyte as the electrolyte, and therefore a solid-state battery may use a combination of a solid electrolyte and a liquid electrolyte as the electrolyte. Alternatively, 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 the electrolyte.

[0018] The solid-state battery of the present disclosure may be a lithium-ion secondary battery. Examples of uses of the battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. In particular, the battery is preferably used as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The battery of the present disclosure may also be used as a power source for mobile objects other than vehicles (e.g., trains, ships, and aircraft), or as a power source for electrical appliances such as information processing devices.

[0019] The elements constituting the solid-state battery of the present disclosure will be described below.

[0020] <Electrode laminate> The solid-state battery 10 of the present disclosure includes an electrode stack 110. The electrode stack functions as a power-generating element of the battery. As illustrated in FIGS. 2 and 3 , the electrode stack may include, on both sides of 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. That is, the electrode stack may include, in this 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.

[0021] 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 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.

[0022] The shape of the electrode laminate is not particularly limited, and may have, for example, a top surface, a bottom surface opposite 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, and examples thereof include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms. The shape of the top surface may also be polygonal other than a quadrilateral, or may have a curved shape 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 surface is not particularly limited, and examples thereof include quadrilaterals such as squares, rectangles, rhombuses, trapezoids, and parallelograms.

[0023] The size of the electrode laminate is not particularly limited, and can be appropriately designed depending on, for example, the desired battery characteristics.

[0024] Hereinafter, each of the components that can constitute the electrode stack according to the present disclosure will be described.

[0025] To facilitate understanding of the present disclosure, the components of an electrode stack of a solid-state lithium-ion secondary battery will be described as an example, but the solid-state battery of the present disclosure is not limited to a lithium-ion secondary battery.

[0026] (Positive electrode current collector layer) The conductive material used for the positive electrode current collector layer is not particularly limited, and may be, for example, SUS, aluminum, copper, nickel, iron, titanium, carbon, or the like.

[0027] The shape of the positive electrode current collector layer is not particularly limited, and examples thereof include foil, plate, mesh, etc. Among these, the foil shape is preferred.

[0028] The positive electrode current collector layer may extend from the end face of the electrode stack, and a plurality of positive electrode current collector layers may be joined at the extending portion.

[0029] (Cathode active material layer) 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 intended use and purpose, it may contain additives used in positive electrode active material layers of solid-state batteries, such as a conductive additive or a binder.

[0030] The material of the positive electrode active material is not particularly limited. 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, Li 1+x Mn 2-x-y M y It may be a different 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.

[0031] 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.

[0032] 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.

[0033] (Solid electrolyte layer) The solid electrolyte layer includes at least a solid electrolyte. The solid electrolyte is not particularly limited, and any material that can be used as a solid electrolyte for a solid-state battery can be used. For example, the solid electrolyte may be a sulfide solid electrolyte, an oxide solid electrolyte, a polymer electrolyte, or the like.

[0034] Examples of sulfide solid electrolytes include, but are not limited to, sulfide-based amorphous solid electrolytes, sulfide-based crystalline solid electrolytes, and argyrodite-type solid electrolytes. Specific examples of sulfide solid electrolytes include Li2S-P2S5-based (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 are not limited to these.

[0035] An example of an oxide solid electrolyte is 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 Ti2-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 are not limited to these.

[0036] Polymer electrolytes include, but are not limited to, polyethylene oxide (PEO), polypropylene oxide (PPO), and the like, and copolymers thereof.

[0037] The solid electrolyte may be glass or crystallized glass (glass ceramic). The solid electrolyte layer may contain, in addition to the solid electrolyte described above, a conductive additive, a binder, and the like, as needed. For details about the conductive additive and the binder, see the description of the positive electrode active material layer.

[0038] (Negative electrode active material layer) 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 intended use and purpose, it may contain additives used in negative electrode active material layers of solid-state batteries, such as a conductive additive and a binder.

[0039] The material of the negative electrode active material is not particularly limited, but is preferably capable of absorbing and releasing metal ions such as lithium ions. For example, the negative electrode active material may be, but is not limited to, an oxide-based negative electrode active material, an alloy-based negative electrode active material, a carbon material, or the like.

[0040] The oxide-based negative electrode active material is not particularly limited, and examples thereof include lithium titanate (LTO) particles.

[0041] The alloy-based negative electrode active material is not particularly limited, 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, and solid solutions thereof. The Si alloy-based negative electrode active material can also contain elements other than silicon, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, etc. The Sn alloy-based negative electrode active material can also contain tin, tin oxide, tin nitride, or solid solutions thereof. The Sn alloy-based negative electrode active material can also contain elements other than tin, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, etc.

[0042] The carbon material is not particularly limited, and examples thereof include hard carbon, soft carbon, graphite, and the like.

[0043] For the solid electrolyte used in the negative electrode active material layer, the above description regarding the solid electrolyte layer can be referred to, and for the conductive additive and binder, the above description regarding the positive electrode active material layer can be referred to.

[0044] (negative electrode current collector layer) The conductive material used for the negative electrode current collector layer is not particularly limited, and may be, for example, SUS, aluminum, copper, nickel, iron, titanium, carbon, or the like, but is not limited to these.

[0045] The shape of the negative electrode current collector layer is not particularly limited, and examples thereof include foil, plate, mesh, etc. Among these, foil is preferred.

[0046] The negative electrode current collector layer may extend from the end face of the electrode stack, and a plurality of negative electrode current collector layers may be joined at the extending portion.

[0047] <Insulating materials> 2 and 3, the insulating member 120 may have a shape that is recessed toward the electrode stack 110. This configuration can improve the ability of the insulating member to conform to the bending of the second current collector layer compared to when the insulating member has a shape that is not recessed toward the electrode stack, thereby improving the reliability of insulation provided by the insulating member. In addition, the amount of material used for the insulating member can be reduced.

[0048] When the insulating member has a recessed shape toward the electrode stack, the length L1 of the portion of the insulating member that contacts 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. This configuration allows the second current collector layer to be appropriately reinforced. Furthermore, the insulating member can be positioned without excessively impairing the volumetric efficiency in the planar direction of the electrode stack, i.e., the x-direction in FIGS. 2 and 3 .

[0049] When the insulating member has a shape recessed toward the electrode laminate, the length L2 from the end face of the electrode laminate to the apex of the recess 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. This configuration ensures insulation by the insulating member and reduces the amount of material used for the insulating member. Note that in FIG. 2 , the recess formed near the center of the electrode laminate in the stacking direction and the two recesses formed along the second current collector layer may be recesses. Also, while FIG. 2 illustrates an embodiment in which the length L2 of each recess is equal, the length L2 of each recess may be different.

[0050] The insulating member 120 may contain a thermoplastic resin or may be a thermoplastic resin. There are no particular limitations on the thermoplastic resin, and it may be a non-reactive or reactive type. There are no particular limitations on the non-reactive thermoplastic resin, and examples thereof include ethylene vinyl acetate (EVA)-based, synthetic rubber-based, olefin-based, polyamide-based, and polyester-based resins such as polyethylene terephthalate (PET). There are no particular limitations on the reactive resin, and examples thereof include urethane-based resins.

[0051] The insulating member 120 may contain a curable resin or may be a curable resin. The curable resin is not particularly limited, and examples thereof include a thermosetting resin and a photocurable resin. Examples of such resins include acrylic and epoxy resins.

[0052] The shape of the insulating member 120 is not particularly limited, but as described above, it may be particularly recessed toward the electrode stack 110.

[0053] The size of the insulating member 120 is not particularly limited, but can be appropriately designed taking into consideration the volumetric efficiency of the battery and the like.

[0054] <Laminating film> The solid state battery 10 of the present disclosure may have a laminate film 130. The laminate film may house an electrode stack. Specifically, the laminate film may house the electrode stack by rolling it up. The laminate film may also be composed of first and second films, and in this case, the electrode stack may be housed by being sandwiched between the first and second films from above and below in the stacking direction of the electrode stack.

[0055] The laminate film may have 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.

[0056] The thickness of each layer constituting the laminate film and the laminate film itself 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.

[0057] <Collector terminal> The solid state battery 10 of the present disclosure may further include a current collecting terminal 140. The current collecting terminal may be electrically connected to the current collecting portion of the electrode stack. The material of the current collecting terminal is not particularly limited as long as it has a current collecting function. As illustrated in FIG. 1, the positive electrode current collecting terminal and the negative electrode current collecting terminal may be disposed 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 disposed spaced apart from each other on one side surface of the electrode stack.

[0058] The shape and size of the current collecting terminal are not particularly limited.

[0059] When the solid-state battery according to the present disclosure has a current collecting terminal, the laminate film may house the electrode stack together with the current collecting terminal. Specifically, the laminate film may house the electrode stack together with the current collecting terminal by winding the electrode stack and the current collecting terminal. The laminate film may also be composed of first and second films. In this case, the first and second films may sandwich the electrode stack and the current collecting terminal from above and below in the stacking direction of the electrode stack, housing the electrode stack together with the current collecting terminal.

[0060] <<Solid-state battery manufacturing method>> A first method of the present disclosure for manufacturing the solid-state battery 10 will be described below.

[0061] As illustrated in FIG. 4 , the method of the present disclosure for manufacturing the solid-state battery 10 includes the following steps: (a) laminating 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 to form a preliminary laminate 100; (b) applying an insulating member 120 to a portion of the second current collector layer 115; (c) laminating the second current collector layer 115 on a main surface of the preliminary laminate 100 so that the end surface of the electrode laminate 110 and the insulating member 120 coincide in the surface direction of the preliminary laminate 100; (d) pressing the second current collector layer 115 to flow the insulating member 120 onto the end surface of the preliminary laminate 100 to form an electrode laminate 110 in which the insulating member 120 is disposed on at least a portion of the end surface; and (e) solidifying the insulating member 120.

[0062] That is, according to the method of the present disclosure, the insulating member is applied so as to connect the end surface of the electrode stack and the second current collector layer. The method of the present disclosure also includes solidifying the insulating member. This strengthens the adhesion of the insulating member to the electrode stack, making it less likely to peel off from the electrode stack. As a result, the reliability of the insulation provided by the insulating member can be improved.

[0063] The method of the present disclosure also includes pressing the second current collector layer to flow the insulating material onto the end surface of the pre-laminate. Therefore, the thickness of the solid-state battery produced by the method of the present disclosure is substantially uniform, resulting in improved volumetric efficiency of the battery.

[0064] In the present disclosure, the term "pre-laminate" refers to 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 which can form an electrode laminate by laminating a second current collector layer thereon.

[0065] <Pre-laminate formation process> The method of the present disclosure includes (a) laminating 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 to form a preliminary laminate 100.

[0066] The method for laminating each layer is not particularly limited, and examples thereof include dry molding such as powder compaction and wet molding using a slurry. For example, in the case of wet molding, a first electrode mixture slurry capable of forming a first electrode active material layer is first applied to one surface of a first current collector layer and then dried, thereby laminating the first electrode active material layer on the first current collector layer. A solid electrolyte layer can be similarly laminated on the first electrode active material layer by using a solid electrolyte slurry. A second electrode mixture slurry can be similarly laminated on the solid electrolyte layer.

[0067] The height H of the pre-laminate shown in FIG. 5, 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 more, or 500 μm or less, 300 μm or less, 200 μm or less, or 150 μm or less.

[0068] <Insulating material application process> 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 .

[0069] 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 laminate) (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, or may be 5 mm or less, 4 mm or less, 3 mm or less, or 2 mm or less.

[0070] The amount of insulating member applied to the second current collector layer can be defined by the thickness T of the insulating member (the length in the stacking direction of the electrode stack) (see FIG. 5 ). For example, this thickness T may be 10 μm or more, 50 μm or more, 75 μm or more, or 100 μm or more, and may be 300 μm or less, 200 μm or less, 150 μm or less, or 100 μm or less.

[0071] The method for applying the insulating member is not particularly limited, and examples thereof include a method in which the insulating member is applied.

[0072] <Second current collector layer lamination step> As illustrated in FIG. 4(b), the method of the present disclosure includes (c) laminating a second current collector layer 115 on the main surface of the pre-laminate 100 so that the end face of the pre-laminate 100 and the insulating member 120 are aligned in the plane direction of the pre-laminate 100.

[0073] The position where the second current collector layer is laminated can be determined by the length L1 of the portion of the insulating member that extends from the end face of the electrode laminate. As described above, this length L1 may be, for example, 100 μm or more, 300 μm or more, 500 μm or more, or 1 mm or more, or may be 3 mm or less, 2 mm or less, 1 mm or less, or 500 μm or less.

[0074] The thickness T, length L1, and height H may satisfy the following relationship: T(μm)×L1(mm)×1000>10(μm)×H(μm) / 2.

[0075] By satisfying this relationship, the insulating properties of the insulating member can be ensured without substantially increasing the thickness of the battery in the area where the insulating member is applied. Furthermore, by satisfying this relationship, it is easy to form the insulating member in a shape that is recessed toward the electrode stack (see Figures 2 and 4(c)).

[0076] <Electrode laminate formation process> As illustrated in FIGS. 4(b) and (c), the method of the present disclosure includes (d) pressing the second current collector layer 115 to flow the insulating member 120 onto the end surface of the pre-laminate 100, thereby forming an electrode laminate 110 having the insulating member 120 disposed on the end surface.

[0077] The method for pressing the second current collector layer is not particularly limited, but may be, for example, a method of pressing using a pressing member, as exemplified in FIG. 4(b).

[0078] The pressing direction is not particularly limited. For example, the second current collector layer may be pressed in the stacking direction of the pre-laminate, and in particular, the second current collector layer may be pressed so as to apply a force toward the end face of the pre-laminate. Pressing the second current collector layer so as to apply a force toward the end face of the pre-laminate allows the insulating member to flow effectively toward the end face of the pre-laminate.

[0079] <Insulating material solidification process> The method of the present disclosure includes (e) solidifying the insulating member 120.

[0080] In the method of the present disclosure, the insulating member may contain a thermoplastic resin, and in this case, step (d) may further include melting the thermoplastic resin, and the insulating member containing the molten thermoplastic resin may be caused to flow onto the end surface of the pre-laminate, and in step (e), the insulating member containing the molten thermoplastic resin may be solidified.

[0081] For the thermoplastic resin, reference can be made to the above description regarding the solid-state battery of the present disclosure.

[0082] When the insulating member contains a thermoplastic resin, the second current collector layer may be heated to melt the thermoplastic resin, and the second current collector layer may be pressed to cause the insulating member containing the molten thermoplastic resin to flow onto the end face of the pre-laminate. In particular, the second current collector layer may be heated and pressed simultaneously using, for example, a heat bar or the like.

[0083] The method for solidifying the insulating member containing the molten thermoplastic resin is not particularly limited, but examples thereof include a method of cooling the insulating member, and a method of cooling the insulating member is not particularly limited, but examples thereof include an air-cooling method.

[0084] 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.

[0085] For the curable resin, reference can be made to the above description regarding the solid-state battery of the present disclosure.

[0086] The method for curing the insulating member containing the curable resin is not particularly limited. For example, if the curable resin is a photocurable resin, the curable resin can be cured by irradiating it with ultraviolet light or the like. If the curable resin is a thermosetting resin, the curable resin can be cured by heating it.

[0087] A second method of the present disclosure for producing the solid-state battery 10 will now be described.

[0088] As illustrated in FIG. 6 , the method of the present disclosure for manufacturing a solid-state 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 this order on both sides of a first current collector layer 111 to form a pre-laminate 100; (b) stacking a first second current collector layer 115 on one main surface of the pre-laminate 100; (c) applying an insulating member 120 to an end surface of the pre-laminate 100 and to at least a portion of the first second current collector layer 115 extending from the pre-laminate 100; (d) stacking a second second current collector layer 115 on the other main surface of the pre-laminate 100; (e) pressing the second second current collector layer 115 to form an electrode laminate 110 having an insulating member 120 disposed on the end surface; and (f) solidifying the insulating member 120.

[0089] That is, the method of the present disclosure includes solidifying the insulating member applied to connect the end face of the electrode stack and the second current collector layer. This strengthens the adhesion of the insulating member to the electrode stack, making it less likely to peel off from the electrode stack. As a result, the reliability of insulation provided by the insulating member can be improved.

[0090] The method of the present disclosure also includes pressing the second current collector layer to crush the insulating member to form an electrode stack having the insulating member disposed on the end surface thereof. Therefore, the thickness of the solid-state battery produced by the method of the present disclosure is substantially uniform, resulting in improved volumetric efficiency of the battery.

[0091] <Pre-laminate formation process> The method of the present disclosure includes (a) laminating 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 to form a preliminary laminate 100.

[0092] For the method of laminating each layer, reference can be made to the above description of the first method of manufacturing the solid state battery 10 of the present disclosure.

[0093] <First step: laminating the second current collector layer> As illustrated in FIG. 6( a ), the method of the present disclosure includes (b) laminating a first second current collector layer 115 onto one major surface of the pre-laminate 100 .

[0094] 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 disposing the metal foil on the second electrode active material layer of the preliminary laminate can be mentioned.

[0095] <Insulating material application process> As illustrated in FIG. 6(b), the method of the present disclosure includes (c) applying an insulating member 120 to the end face of the pre-laminate 100 and to at least a portion of the surface of the first second current collector layer 115 that is in contact with the pre-laminate 100 and that extends from the pre-laminate.

[0096] The method for applying the insulating member is not particularly limited, and examples thereof include a method in which the insulating member is applied.

[0097] The insulating member applied to the desired location can wet and spread onto the first second current collector layer due to surface tension.

[0098] <Second current collector layer lamination process> 6(c), the method of the present disclosure includes (d) laminating a second second current collector layer on the other main surface of the pre-laminate 100. The method for laminating the second second current collector layer is not particularly limited, but may be the same as the method for laminating the first second current collector layer.

[0099] <Electrode laminate formation process> As illustrated in FIGS. 6(c) and (d), the method of the present disclosure includes (e) pressing a second current collector layer 115 to form an electrode stack 110 having an insulating member 120 disposed on the end surface.

[0100] The method for pressing the second current collector layer is not particularly limited, but may be, for example, a method of pressing using a pressing member, as exemplified in FIGS. 6(c) and (d).

[0101] The pressing direction is not particularly limited. For example, the second current collector layer may be pressed in the stacking direction of the pre-laminate, and in particular, as illustrated in FIG. 6(c), the second current collector layer may be pressed so as to apply a force toward the end face of the pre-laminate. Pressing the second current collector layer so as to apply a force toward the end face of the pre-laminate makes it difficult for the insulating member to penetrate between the pre-laminate and the second current collector layer. As a result, an increase in the thickness of the portion of the solid-state battery where the insulating member is disposed can be effectively suppressed.

[0102] As illustrated in FIG. 6(d), the insulating member can wet and spread on the second current collector layer due to surface tension, resulting in the insulating member having a shape recessed toward the electrode stack (see FIGS. 3 and 6(e)).

[0103] <Insulating material solidification process> The method of the present disclosure includes (f) solidifying the insulating member 120.

[0104] In the method of the present disclosure, the insulating member may contain a thermoplastic resin, in which case, step (c) may further include melting the insulating member containing the thermoplastic resin, and step (f) may include solidifying the molten insulating member containing the thermoplastic resin.

[0105] For the thermoplastic resin, reference can be made to the above description regarding the solid-state battery of the present disclosure.

[0106] When the insulating member contains a thermoplastic resin, for example, in step (c), a pre-melted insulating member containing a thermoplastic resin may be applied, or the insulating member containing a thermoplastic resin may be melted after being placed at a desired position. Furthermore, the thermoplastic resin may be kept in a molten state in steps (d) and (e).

[0107] The method for solidifying the insulating member containing the molten thermoplastic resin is not particularly limited, but examples thereof include a method of cooling the insulating member, and a method of cooling the insulating member is not particularly limited, but examples thereof include an air-cooling method.

[0108] 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 solidified by curing.

[0109] For the curable resin, reference can be made to the above description regarding the solid-state battery of the present disclosure.

[0110] The method for curing the insulating member containing the curable resin is not particularly limited. For example, if the curable resin is a photocurable resin, the curable resin can be cured by irradiating it with ultraviolet light or the like. If the curable resin is a thermosetting resin, the curable resin can be cured by heating it.

[0111] Battery module 7, the battery module 1 of the present disclosure includes the solid-state battery 10 of the present disclosure. For the solid-state battery of the present disclosure, reference can be made to the above description regarding the solid-state battery of the present disclosure.

[0112] Since the thickness of the solid state battery of the present disclosure is substantially 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.

[0113] The number of solid-state batteries of the present disclosure in the battery module of the present disclosure is not particularly limited and may be at least one. In the battery module of the present disclosure, all batteries may be solid-state batteries of the present disclosure. Note that, although FIG. 7 illustrates an embodiment in which the number of solid-state batteries is two, the number of solid-state batteries in the battery module of the present disclosure is not limited to this. [Explanation of symbols]

[0114] 1 Battery Module 10 solid state battery 100 Pre-laminate 110 Electrode laminate 111 First current collector layer 112 First electrode active material layer 113 Solid electrolyte layer 114 Second electrode active material layer 115 Second current collector layer 120 Insulating material 130 Laminating Film 140 Current collector terminal

Claims

1. A solid-state battery having an electrode stack, the electrode stack has, in this 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 part 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 the end surface of the electrode stack along the second current collector layer; solid state battery.

2. the electrode stack has 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; The solid-state battery according to claim 1 .

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

4. 4. The solid-state battery according to claim 1, 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. A method for producing the solid state battery according to any one of claims 1 to 3, comprising the following steps: (a) forming a preliminary laminate 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 portion of the second current collector layer; (c) laminating the second current collector layer on the main surface of the pre-laminate so that the end surface of the pre-laminate and the insulating member coincide with each other in a surface direction of the pre-laminate; (d) pressing the second current collector layer to cause the insulating member to flow onto the end surface of the preliminary laminate, thereby forming the electrode laminate in which the insulating member is disposed on at least a part of the end surface; and (e) solidifying the insulating material;

7. the insulating member contains a thermoplastic resin, The step (d) further includes melting the thermoplastic resin, causing the insulating member containing the molten thermoplastic resin to flow onto the end surface of the pre-laminate; and In the step (e), the insulating member containing the molten thermoplastic resin is solidified. The method of claim 6.

8. the insulating member is a curable resin, and In the step (e), the insulating member containing the curable resin is hardened to be solidified. The method of claim 6.

9. A method for producing the solid state battery according to claim 3, comprising the steps of: (a) forming a preliminary laminate 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) laminating a first second current collector layer on one main surface of the preliminary laminate; (c) applying the insulating member to an end surface of the pre-laminate and at least a part of a portion of a first second current collector layer extending from the pre-laminate; (d) laminating a second current collector layer on the other main surface of the preliminary laminate; (e) pressing the second current collector layer to form the electrode stack having the insulating member disposed on an end surface thereof; and (f) solidifying the insulating material;

10. the insulating member contains a thermoplastic resin, The step (c) further includes melting the insulating member containing the thermoplastic resin; and In the step (f), the insulating member containing the molten thermoplastic resin is solidified.

10. The method of claim 9.

11. the insulating member includes a curable resin; and In the step (f), the insulating member containing the curable resin is hardened to be solidified.

10. The method of claim 9.

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