Solid battery and method for manufacturing solid battery

Abstract

To provide a solid-state battery comprising a bipolar electrode plate, capable of reducing a lamination space factor of a solid electrolyte as well as reducing resistivity.SOLUTION: A solid-state battery comprises a lamination body formed by laminating a positive electrode plate, one or a plurality of bipolar electrode plates, and a negative electrode plate. In a lamination surface of the bipolar electrode plate, a solid electrolyte layer is formed. In at least one of an end surface of the bipolar electrode plate, the solid electrolyte layer is formed. The bipolar electrode plate is a plurality of bipolar electrode plates. In the end surface of each bipolar electrode plate, a concave part with the solid electrolyte layer and a convex part without the solid electrolyte layer are formed. It is preferable that the concave part and the convex part be alternately arranged between the adjacent bipolar electrode plates.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a solid battery and a method for manufacturing the same.

Background Art

[0002] Conventionally, lithium-ion secondary batteries have been widely popular as secondary batteries having a high energy density. A lithium-ion secondary battery has a structure in which a separator is present between a positive electrode and a negative electrode and a liquid electrolyte is filled.

[0003] Since the electrolytic solution of a lithium-ion secondary battery is usually a flammable organic solvent, there has been a problem in particular with respect to safety against heat. Therefore, solid batteries using an inorganic solid electrolyte instead of an organic liquid electrolyte have been proposed. For example, a technique related to a solid battery including a laminate having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer has been proposed (see Patent Document 1).

[0004] Also in a solid battery using a bipolar electrode plate, a configuration is adopted in which a solid electrolyte layer is laminated between the bipolar electrode plates.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the solid battery described in Patent Document 1, a sheet-like solid electrolyte layer formed by pressure molding is disposed between the electrode layers. Since the sheet-like solid electrolyte layer requires strength, a thickness of about several tens of μm is required. For this reason, there has been room for improvement in terms of an increase in the stacking occupancy rate of the solid electrolyte and an increase in the resistivity due to an increase in the distance between the electrodes.

[0007] The present invention has been made in view of the above, and an object thereof is to provide a solid-state battery including a bipolar electrode plate capable of reducing the stacking occupation ratio of a solid electrolyte and reducing the resistivity.

Means for Solving the Problems

[0008] (1) The present invention relates to a solid-state battery including a laminate formed by laminating a positive electrode plate, one or more bipolar electrode plates, and a negative electrode plate, wherein a solid electrolyte layer is formed on a lamination surface of the bipolar electrode plate.

[0009] According to the invention of (1), it is possible to provide a solid-state battery including a bipolar electrode plate capable of reducing the stacking occupation ratio of a solid electrolyte and reducing the resistivity.

[0010] (2) The solid-state battery according to (1), wherein a solid electrolyte layer is formed on at least a part of an end face of the bipolar electrode plate.

[0011] According to the invention of (2), insulation between end faces of the bipolar electrode plates can be ensured.

[0012] (3) The bipolar electrode plate is a plurality of bipolar electrode plates, and a concave portion where a solid electrolyte layer is formed and a convex portion where a solid electrolyte layer is not formed are formed on an end face of the bipolar electrode plate, and the concave portion and the convex portion are alternately arranged between adjacent bipolar electrode plates. The solid-state battery according to (1) or (2).

[0013] According to the invention of (3), even when a thin solid electrolyte layer is formed on the electrode plate instead of the sheet-like solid electrolyte layer, insulation between the electrode plates can be ensured.

[0014] (4) In the bipolar electrode plate disposed adjacent to the positive electrode plate or the negative electrode plate, the concave portion is disposed at a position corresponding to an electrode tab extending from the positive electrode plate or the negative electrode plate and is wider than the width of the electrode tab. The solid-state battery according to (3).

[0015] According to the invention of (4), insulation can be ensured between the end face of the bipolar electrode plate and the electrode tab extending from the positive electrode plate or the negative electrode plate, and a laminate can be formed without forming a solid electrolyte layer on the positive electrode plate and the negative electrode plate. Therefore, the manufacturing process of the solid battery can be simplified.

[0016] The solid battery according to any one of (1) to (4), wherein a solid electrolyte layer is formed on the lamination surface of the positive electrode plate and the negative electrode plate.

[0017] According to the invention of (5), a laminate can be formed that can ensure insulation between the positive electrode plate and the negative electrode plate and the end face of the bipolar electrode plate.

[0018] The solid battery according to any one of (1) to (5), wherein the bipolar electrode plate is a plurality of bipolar electrode plates, and the shapes of the adjacent bipolar electrode plates are in a mirror image relationship with each other.

[0019] According to the invention of (6), the shape of the bipolar electrode plate can be made into a shape suitable for ensuring insulation between the end faces of the bipolar electrode plates.

[0020] Further, the present invention relates to a method for manufacturing a solid battery including a manufacturing process of a bipolar electrode plate. The manufacturing process of the bipolar electrode plate includes a step of coating a positive electrode material on one surface of a current collector plate and coating a negative electrode material on the other surface, a drilling step of forming a hole in a part of the current collector plate coated with the electrode material, a solid electrolyte coating step of coating a solid electrolyte on the current collector plate coated with the electrode material, and a cutting step of cutting the current collector plate coated with the electrode material with a cutting line including the hole so that a concave portion is formed at the edge of the current collector plate, in this order.

[0021] According to the invention of (7), a bipolar electrode plate having a solid electrolyte layer formed on at least a part of the end face can be efficiently manufactured, and the manufacturing cost of the solid battery can be reduced.

[0022] (8) In the manufacturing process of the bipolar electrode plate, the drilling process is a process of forming the holes such that the holes in an adjacent row are staggered, and two types of bipolar electrode plates having a mirror image relationship with each other are manufactured. The method for manufacturing a solid-state battery according to (7).

[0023] According to the invention of (8), since two types of bipolar electrode plates having a mirror image relationship with each other can be manufactured from a single sheet-shaped current collector plate, the manufacturing cost of the solid-state battery can be reduced.

Brief Description of the Drawings

[0024]

Figure 1

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Embodiments for Carrying Out the Invention

[0025] 《First Embodiment》 <Solid-state battery> The solid-state battery according to this embodiment includes a laminate formed by laminating a positive electrode plate, a bipolar electrode plate, and a negative electrode plate. The laminate is housed in an outer package, and the positive electrode plate and the negative electrode plate are electrically connected to the positive electrode and the negative electrode, respectively.

[0026] [Laminate] As shown in FIGS. 1 and 2A to 2D, the laminate 1 according to this embodiment has a configuration in which a positive electrode plate 20 and a negative electrode plate 30 are arranged at both ends of the laminate, and two types of bipolar electrode plates 50a and 50b are alternately laminated between the positive electrode plate 20 and the negative electrode plate 30.

[0027] (Positive electrode plate) As shown in FIGS. 2A to 2D, the positive electrode plate 20 has a positive electrode current collector plate 21, a positive electrode active material layer 22 containing a positive electrode active material formed on the positive electrode current collector plate 21, a solid electrolyte layer 40 containing a solid electrolyte formed on the positive electrode active material layer 22, and a positive electrode tab 211 formed by extending the positive electrode current collector plate 21.

[0028] The positive electrode current collector plate 21 is not particularly limited and is composed of a known current collecting material that can be used for the positive electrode of a solid-state battery. For example, it is composed of aluminum, aluminum alloy, stainless steel, nickel, iron, titanium, or the like.

[0029] As the positive electrode active material constituting the positive electrode active material layer 22, there is no particular limitation, and a known material capable of occluding and releasing a charge transfer medium such as lithium ions can be appropriately selected and used. For example, lithium cobaltate, lithium nickelate, lithium manganate, hetero-element substituted Li-Mn spinel, lithium metal phosphate, lithium sulfide, sulfur, etc. may be mentioned. Specifically, LiCoO 2 , Li(Ni 5 / 10 Co 2 / 10 Mn 3 / 10 )O 2、 Li(Ni 6 / 10 Co 2 / 10 Mn 2 / 10 )O 2、 Li(Ni 8 / 10 Co 1 / 10 Mn 1 / 10 )O 2、 Li(Ni 0.8 Co 0.15 Al 0.05 )O 2、 Li(Ni 1 / 6 Co 4 / 6 Mn 1 / 6 )O 2、 Li(Ni 1 / 3 Co 1 / 3 Mn 1 / 3 )O 2、 LiCoO 4 , LiMn 2 O 4 , LiNiO 2 , LiFePO 4 etc. may be mentioned. The positive electrode active material layer 22 may optionally contain a conductive assistant, a binder, etc. in addition to the positive electrode active material.

[0030] (Negative electrode plate) As shown in FIGS. 2A to 2D, the negative electrode plate 30 has a negative electrode current collector 31, a negative electrode active material layer 32 containing a negative electrode active material formed on the negative electrode current collector, a solid electrolyte layer 40 containing a solid electrolyte formed on the negative electrode active material layer 32, and a negative electrode tab 311 formed by extending the negative electrode current collector 31.

[0031] The negative electrode active material constituting the negative electrode active material layer 32 is not particularly limited, and known materials capable of occluding and releasing a charge transfer medium such as lithium ions can be appropriately selected and used. For example, lithium transition metal oxides such as lithium titanate, TiO 2 、Nb 2 O 3 and WO 3 and other transition metal oxides, Si, SiO, metal sulfides, metal nitrides, and carbon materials such as artificial graphite, natural graphite, graphite, soft carbon and hard carbon, and metal lithium, metal indium and lithium alloys. The negative electrode active material layer 32 may optionally contain a conductive auxiliary agent, a binder, etc. in addition to the negative electrode active material.

[0032] (Bipolar electrode plate) As shown in FIGS. 2A to 2D, the bipolar electrode plates 50a and 50b are electrode plates in which a positive electrode active material layer 22 serving as a positive electrode of a bipolar electrode is formed on one surface of a current collector plate 51, and a negative electrode active material layer 32 serving as a negative electrode of the bipolar electrode is formed on the other surface. The configurations of the positive electrode active material layer 22 and the negative electrode active material layer 32 can adopt the same configurations as described above. A solid electrolyte layer 40 containing a solid electrolyte is formed on the positive electrode active material layer 22 and the negative electrode active material layer 32. The current collector plate 51 is not particularly limited, and examples thereof include stainless steel foil.

[0033] The solid electrolyte layer 40 is a layer having a thickness of about several μm formed on the positive electrode active material layer 22 and the negative electrode active material layer 32 of the positive electrode plate 20, the negative electrode plate 30, and the bipolar electrode plates 50a and 50b, and is a layer containing at least a solid electrolyte material which is a solid or gel-like electrolyte. Charge transfer between the positive electrode active material and the negative electrode active material can be performed through the solid electrolyte material. The solid electrolyte material contained in the solid electrolyte layer 40 is not particularly limited, and for example, a sulfide solid electrolyte material, an oxide solid electrolyte material, a nitride solid electrolyte material, a halide solid electrolyte material, etc. can be used.

[0034] By forming the solid electrolyte layer 40 on the positive electrode active material layer 22 and the negative electrode active material layer 32, the thickness of the solid electrolyte layer 40 can be made about several micrometers, so that the stacking occupation ratio of the solid electrolyte can be reduced and the resistivity can be reduced. Further, due to the configuration of the bipolar electrode described below, the solid-state battery according to the present embodiment has the advantages that it can ensure insulation between electrodes while having a thin solid electrolyte layer, and can further simplify the manufacturing process and structure.

[0035] The configurations of the bipolar electrode plates 50a and 50b are shown in FIGS. 3 and 4, respectively. FIGS. 3 and 4 are views of the bipolar electrode plates 50a and 50b, respectively, viewed from the side of the laminated surface on which the positive electrode active material layer 22 is formed. The shapes of the bipolar electrode plates 50a and 50b are in a mirror image relationship with each other, with convex portions 51a and concave portions 52a alternately formed on the end faces. The solid electrolyte layer 40 is not formed on the end face of the convex portion 51a, and the solid electrolyte layer 40 is formed on the end face of the concave portion 52a. In the laminate 1, the bipolar electrode plates 50a and 50b are alternately laminated as shown in FIGS. 2A to 2D. The number of laminations of the bipolar electrode plates 50a and 50b is not particularly limited as long as the bipolar electrode plates 50a and 50b are alternately laminated. When simply laminating the bipolar electrode plates, ensuring insulation between the end faces becomes a problem, but by alternately laminating the bipolar electrode plates 50a and 50b having the above configuration, insulation between the bipolar electrode plates 50a and 50b can be ensured.

[0036] As shown in FIG. 1, the convex portions 51a and the concave portions 52a of the bipolar electrode plates 50a and 50b are arranged so as to be staggered when viewed from the stacking direction. Also, the width of the concave portion 52a is wider than that of the convex portion 51a. Thereby, as shown in FIGS. 1, 2A, and 2D, an insulating distance L1a can be ensured between the convex portions 51a of the bipolar electrode plates 50a and 50b when viewed from the stacking direction, and an insulating distance L1b can be ensured when viewed from the stacking cross section. The width of the concave portion 52a is not particularly limited, but can be made wider than the width T1 of the positive electrode tab 211 and the negative electrode tab 311, for example, and the width of the convex portion 51a can be made narrower than the width T1, for example.

[0037] On the end faces of the bipolar electrode plates 50a and 50b, a convex portion 51a or a concave portion 52a is formed. Thereby, insulation is ensured between the concave portion 52a and the end faces of the positive electrode plate 20 and the negative electrode plate 30. Further, as shown in FIGS. 2A, 2C, and 2D, insulation distances L2a and L2b can be ensured between the end faces of the positive electrode plate 20 and the negative electrode plate 30 where the positive electrode tab 211 and the negative electrode tab 311 are not arranged and the convex portion 51a when viewed from the laminated cross section. The insulation distance L2a is ensured by arranging the convex portion 51a on the outer peripheral side of the end faces of the positive electrode plate 20 and the negative electrode plate 30.

[0038] In the present embodiment, a bipolar electrode plate 50a is provided adjacent to the positive electrode plate 20 and the negative electrode plate 30. On the positive electrode tab 211 and the negative electrode tab 311, as shown in FIGS. 2A and 2C, a solid electrolyte layer 40 having a certain length in the tab extending direction is formed on the laminated surface. Thereby, as shown in FIG. 1, an insulation distance L3a can be ensured between the positive electrode tab 211 and the negative electrode tab 311 and the convex portion 51a of the bipolar electrode plate 50a when viewed from the stacking direction. Further, as shown in FIG. 2A, an insulation distance L3b can be ensured between the positive electrode tab 211 and the convex portion 51a of the bipolar electrode plate 50b when viewed from the laminated cross section. Similarly, as shown in FIG. 2C, an insulation distance L3c can be ensured between the negative electrode tab 311 and the convex portion 51a of the bipolar electrode plate 50a when viewed from the laminated cross section.

[0039] <Method for manufacturing a solid-state battery> The method for manufacturing a solid-state battery according to the present embodiment includes, as shown in FIG. 12, a positive electrode plate manufacturing step S1, a bipolar electrode plate manufacturing step S2, a negative electrode plate manufacturing step S3, a lamination step S4, and a pressing step S5.

[0040] The positive electrode plate manufacturing step S1 includes, as shown in FIG. 12, an electrode material coating step S11, a drying step S12, a solid electrolyte coating step S13, a drying step S14, and a cutting step 15 in this order.

[0041] The positive electrode coating process S11 is a process of forming a positive electrode active material layer 22 on both sides of a sheet-shaped positive electrode current collector plate 21 as shown in FIG. 10. The method of forming the positive electrode active material layer 22 is not particularly limited, and examples thereof include a method of preparing a positive electrode mixture containing a positive electrode active material and applying the positive electrode mixture onto a positive electrode current collector. The method of application is also not particularly limited, and examples thereof include a doctor blade method, spray coating, screen printing, etc. The drying process S12 is a process of drying the applied positive electrode mixture, and the drying method is not particularly limited.

[0042] The solid electrolyte coating process S13 is a process of forming a solid electrolyte layer 40 on both sides of a sheet-shaped positive electrode current collector plate 21 having positive electrode active material layers 22 formed on both sides as shown in FIG. 10. The method of forming the solid electrolyte layer 40 is not particularly limited, and similar to the positive electrode coating process S11, examples thereof include a method of applying a solid electrolyte by a doctor blade method, spray coating, screen printing, etc. The drying process S14 is a process of drying the applied solid electrolyte layer 40, and the drying method is not particularly limited.

[0043] The cutting process S15 is a process of forming a positive electrode tab 211 by cutting the sheet-shaped positive electrode current collector plate 21 into a predetermined size.

[0044] The bipolar electrode plate manufacturing process S2 includes, in this order, a positive electrode coating process S21, a drying process S22, a drilling process S23, a solid electrolyte coating process S24, a drying process S25, and a cutting process 26 as shown in FIG. 12.

[0045] The positive electrode coating process S21 is a process of forming a positive electrode active material layer 22 on one surface of a sheet-shaped current collector plate 51 and a negative electrode active material layer 32 on the other surface as shown in FIG. 9. As a specific method, the same processes as the positive electrode coating process S11 and the positive electrode coating process S31 can be adopted. The drying process S22 is a process of drying the applied positive electrode mixture and negative electrode mixture, and the drying method is not particularly limited.

[0046] The drilling step S23 is a step of forming holes in a sheet-shaped current collector plate 51 having a positive electrode active material layer 22 and a negative electrode active material layer 32 formed on both sides thereof. The method of forming the holes is not particularly limited, and conventionally known methods such as a method of performing drilling with a punching die and a method by laser processing can be used. As shown in FIG. 9, the drilling step S23 is preferably a step of forming the holes such that adjacent holes in a row are staggered. Thereby, bipolar electrode plates 50a and 50b having two types of shapes in a mirror image relationship can be manufactured from a single sheet-shaped current collector plate 51.

[0047] The solid electrolyte coating step S24 is a step of forming a solid electrolyte layer 40 on both sides of a sheet-shaped current collector plate 51 having a positive electrode active material layer 22 and a negative electrode active material layer 32 formed on both sides thereof and having holes formed therein, as shown in FIG. 9. The method of forming the solid electrolyte layer 40 is not particularly limited, and examples thereof include a method of coating the solid electrolyte by a doctor blade method, spray coating, screen printing, etc., similar to the electrode material coating step S11. By coating the solid electrolyte on the current collector plate 51 having holes formed therein, the solid electrolyte can wrap around the end faces of the holes, and the solid electrolyte layer 40 can also be formed on the end faces of the holes. The drying step S25 is a step of drying the applied solid electrolyte layer 40, and the drying method is not particularly limited.

[0048] The cutting step S26 is a step of forming bipolar electrode plates 50a and 50b having convex portions 51a and concave portions 52a formed on the end faces by cutting the sheet-shaped current collector plate 51 along a cutting line including the holes formed in the drilling step S23.

[0049] According to the bipolar electrode plate manufacturing process S2 having the above steps, bipolar electrode plates 50a and 50b can be manufactured in which convex portions 51a and concave portions 52a are formed on the end faces, and a solid electrolyte layer 40 is formed on the end faces of the concave portions 52a. That is, before cutting the sheet-shaped current collector plate 51, bipolar electrode plates 50a and 50b in which a solid electrolyte is applied to the end faces of the holes and the solid electrolyte layer 40 is formed on at least a part of the end faces can be manufactured, which is preferable from the viewpoint of the production efficiency of the bipolar electrode plates 50a and 50b.

[0050] As shown in FIG. 12, the negative electrode plate manufacturing process S3 includes a negative electrode active material layer coating process S31, a drying process S32, a solid electrolyte coating process S33, a drying process S34, and a cutting process 35 in this order. The negative electrode plate manufacturing process S3 is the same as the positive electrode plate manufacturing process S1 except that in the negative electrode active material layer coating process S31, the negative electrode active material layer 32 is formed on both sides of the sheet-shaped negative electrode current collector plate 31.

[0051] The lamination process S4 is a process of laminating the positive electrode plate 20 manufactured by the positive electrode plate manufacturing process S1, the bipolar electrode plates 50a and 50b manufactured by the bipolar electrode plate manufacturing process S2, and the negative electrode plate 30 manufactured by the negative electrode plate manufacturing process S3. In the lamination process S4, the bipolar electrode plates 50a and 50b are laminated alternately, and the positive electrode plate 20 and the negative electrode plate 30 are arranged at both ends of the lamination.

[0052] The pressing process S5 is a process of integrating the laminated positive electrode plate 20, bipolar electrode plates 50a and 50b, and negative electrode plate 30 by sandwiching them with a press or the like and applying pressure.

[0053] Hereinafter, other embodiments of the present invention will be described. For the same configurations as those described above, the description may be omitted.

[0054] 《Second Embodiment》 [Laminated body] FIG. 5 is a diagram showing an overview of the laminate 1a of the solid-state battery according to the second embodiment. As shown in FIGS. 5 and 6A to 6D, in the laminate 1a, a positive electrode plate 20a and a negative electrode plate 30a are arranged at both ends of the laminate, and two types of bipolar electrode plates 50c and 50d are alternately laminated between the positive electrode plate 20a and the negative electrode plate 30a.

[0055] In the present embodiment, as shown in FIGS. 6A to 6D, a solid electrolyte layer 40 is not formed on the laminated surfaces of the positive electrode plate 20a and the negative electrode plate 30a. Therefore, a solid electrolyte layer is not formed on the surfaces of the positive electrode tab 211 and the negative electrode tab 311 either. For this reason, the manufacturing process of the laminate 1a can be simplified. On the other hand, in the laminate 1a, it is necessary to ensure insulation between the positive electrode tab 211 and the negative electrode tab 311 and the adjacent bipolar electrode plates.

[0056] The configurations of the bipolar electrode plates 50c and 50d are shown in FIGS. 7 and 8 respectively. FIGS. 7 and 8 are views of the bipolar electrode plates 50c and 50d respectively, viewed from the side of the laminated surface on which the positive electrode active material layer 22 is formed. The shapes of the bipolar electrode plates 50c and 50d are shapes that are mirror images of each other, with convex portions 51b and concave portions 52b alternately formed on the end faces. A solid electrolyte layer 40 is not formed on the convex portion 51b, and a solid electrolyte layer 40 is formed on the concave portion 52b. In the laminate 1a, the bipolar electrode plates 50c and 50d are alternately laminated as shown in FIGS. 6A to 6D.

[0057] In the present embodiment, the bipolar electrode plate arranged adjacent to the positive electrode plate 20a is the bipolar electrode plate 50c, and the bipolar electrode plate arranged adjacent to the negative electrode plate 30a is the bipolar electrode plate 50d. For this reason, the number of laminated bipolar electrode plates in the present embodiment is an even number.

[0058] As shown in FIGS. 5 and 7, the recess 52b formed on the end face of the bipolar electrode plate 50c is disposed at a position corresponding to the positive electrode tab 211 having a width T1. Similarly, as shown in FIGS. 5 and 7, the recess 52b formed on the end face of the bipolar electrode plate 50d is disposed at a position corresponding to the negative electrode tab 311 having a width T1. The recess 52b is a recess wider than the widths of the positive electrode tab 211 and the negative electrode tab 311, and a solid electrolyte layer 40 is formed on the end face. Thereby, insulation between the bipolar electrode plate 50c adjacent to the positive electrode tab 211 and insulation between the bipolar electrode plate 50d adjacent to the negative electrode tab 311 can be ensured.

[0059] As shown in FIGS. 5, 6A, and 6D, an insulation distance L1c can be ensured between the convex portions 51a of the bipolar electrode plates 50c and 50d when viewed from the stacking direction, and an insulation distance L1b can be ensured when viewed from the stacking cross section.

[0060] As shown in FIGS. 5A and 5D, insulation distances L2a and L2b can be ensured between the end faces of the positive electrode plate 20 and the negative electrode plate 30 where the positive electrode tab 211 and the negative electrode tab 311 are not disposed and the convex portion 51a when viewed from the stacking cross section.

[0061] As shown in FIG. 5, an insulation distance L3d can be ensured between the positive electrode tab 211 and the convex portion 51a of the bipolar electrode plate 50c when viewed from the stacking direction. The same applies to the negative electrode tab 311 and the convex portion 51a of the bipolar electrode plate 50d. Further, as shown in FIG. 6A, an insulation distance L3b can be ensured between the positive electrode tab 211 and the convex portion 51a of the bipolar electrode plate 50d when viewed from the stacking cross section. Similarly, as shown in FIG. 6C, an insulation distance L3c can be ensured between the negative electrode tab 311 and the convex portion 51a of the bipolar electrode plate 50c when viewed from the stacking cross section. That is, at positions corresponding to the positive electrode tab 211 and the negative electrode tab 311 of the bipolar electrode plate adjacent to the positive electrode plate 20a and the negative electrode plate 30a, recesses 52b having a solid electrolyte layer 40 formed on the end face are provided. Thereby, even if the positive electrode plate 20a and the negative electrode plate 30a do not have the solid electrolyte layer 40, insulation distances L3b, L3c, and L3d can be ensured between the convex portions 51a of the respective bipolar electrode plates.

[0062] <Method for manufacturing a solid-state battery> As shown in FIG. 13, the method for manufacturing a solid-state battery according to this embodiment includes a positive electrode plate manufacturing step S1a, a bipolar electrode plate manufacturing step S2a, a negative electrode plate manufacturing step S3a, a lamination step S4, and a pressing step S5.

[0063] The positive electrode plate manufacturing step S1a and the negative electrode plate manufacturing step S3a are the same as the positive electrode plate manufacturing step S1 and the negative electrode plate manufacturing step S3, except that they do not include a solid electrolyte coating step S13 and S33 and a drying step S14 and S34.

[0064] As shown in FIG. 13, the bipolar electrode plate manufacturing step S2a includes a current collector coating step S21, a drying step S22, a punching step S23a, a solid electrolyte coating step S24, a drying step S25, and a cutting step 26 in this order. Each step of the bipolar electrode plate manufacturing step S2a is the same as the bipolar electrode plate manufacturing step S2, except that the punching step S23a is different.

[0065] As shown in FIG. 11, the punching step S23a is a step of forming holes in a sheet-shaped current collector 51 having a positive electrode active material layer 22 and a negative electrode active material layer 32 formed on both sides. As a method for forming the holes, the same method as in the first embodiment can be adopted. Similar to the punching step S23, the punching step S23a preferably forms the holes so that adjacent holes in a row are staggered as shown in FIG. 11. Thereby, two types of bipolar electrode plates 50c and 50d having shapes in a mirror image relationship can be manufactured from one sheet-shaped current collector 51.

[0066] In the punching step S23a, holes are formed in the current collector 51 so that two rows of bipolar electrode plates can be manufactured along the flow direction of the sheet from one sheet-shaped current collector 51. The two rows of bipolar electrode plates are manufactured so that adjacent bipolar electrode plates have shapes in a mirror image relationship with each other.

[0067] As described above, the preferred embodiments of the present invention have been explained. However, the present invention is not limited to the above embodiments, and those with appropriate modifications are also included in the scope of the present invention. The drilling step S23 of the bipolar electrode plate manufacturing step S2 according to the manufacturing method of the solid battery of the first embodiment was explained with reference to FIG. 9, and the drilling step S23a of the bipolar electrode plate manufacturing step S2a according to the manufacturing method of the solid battery of the second embodiment was explained with reference to FIG. 11. It is not limited to the above. The drilling step shown in FIG. 9 and the drilling step shown in FIG. 11 can be applied to any of the drilling steps S23 and S23a, respectively.

Explanation of Signs

[0068] 1, 1a, 1b Laminates 20, 20a, 20b Positive electrode plates 211 Positive electrode tab (electrode tab) 30, 30a, 30b Negative electrode plates 311 Negative electrode tab (electrode tab) 40 Solid electrolyte layer 50a, 50b, 50c, 50d Bipolar electrode plates 51a, 51b Protrusions 52a, 52b Recesses

Claims

1. A solid battery including a laminate formed by laminating a positive electrode plate, a plurality of bipolar electrode plates, and a negative electrode plate, wherein a solid electrolyte layer is formed on the laminated surface of the bipolar electrode plates, wherein on the end face viewed from the laminated surface side of the bipolar electrode plates, a recess where a solid electrolyte layer is formed and a convex portion where a solid electrolyte layer is not formed are alternately formed, wherein the shapes of the bipolar electrode plates arranged adjacent to each other are in a mirror image relationship with each other, and wherein the recesses and the convex portions are arranged alternately between the adjacent bipolar electrode plates. A solid battery.

2. In the bipolar electrode plate arranged adjacent to the positive electrode plate or the negative electrode plate, the recess is arranged at a position corresponding to an electrode tab extending from the positive electrode plate or the negative electrode plate and is wider than the width of the electrode tab. The solid battery according to claim 1.

3. A solid electrolyte layer is formed on the laminated surfaces of the positive electrode plate and the negative electrode plate. The solid battery according to claim 1 or 2.

4. A method for manufacturing a solid battery according to claim 1, including a manufacturing process of the bipolar electrode plate, wherein the manufacturing process of the bipolar electrode plate includes a step of coating a positive electrode material on one surface of a current collector plate and coating a negative electrode material on the other surface (electrode material coating step), a step of forming holes in a part of the current collector plate coated with the electrode material (drilling step), a step of coating a solid electrolyte on the current collector plate coated with the electrode material (solid electrolyte coating step), and a cutting step of cutting the current collector plate coated with the electrode material with a cutting line including the holes so that the recesses are formed at the edges of the current collector plate. The method for manufacturing a solid battery includes the above steps in this order.

5. In the manufacturing process of the bipolar electrode plate, the drilling step is a step of forming the holes such that the holes in an adjacent row are staggered from each other, and two types of bipolar electrode plates having shapes in a mirror image relationship with each other are manufactured. The method for manufacturing a solid battery according to claim 4.

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