Battery

Abstract

A battery (50) comprises: an electrode layer (10); a counter electrode layer (20) that is disposed opposite the electrode layer; and a solid electrolyte layer (30) that is positioned between the electrode layer and the counter electrode layer. The electrode layer has: a current collector (11); an electrode active material layer (12) that is positioned between the current collector and the solid electrolyte layer; and an insulating layer (13) that is positioned between the current collector and the solid electrolyte layer at ends of the electrolyte layer, and that is connected to the current collector. The electrode active material layer has a region (12a) that does not overlap the insulating layer in plan view. The battery has gaps (14) that are positioned between the current collector and the solid electrolyte layer, and that adjoin the insulating layer.

Description

Technical Field

[0001] The present disclosure relates to a battery.

Background Art

[0002] Patent Documents 1 and 2 disclose a battery including an insulating member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the prior art, improvement in the reliability of a battery has been demanded. Therefore, an object of the present disclosure is to provide a highly reliable battery.

Means for Solving the Problems

[0005] A battery according to an aspect of the present disclosure includes an electrode layer, a counter electrode layer disposed to face the electrode layer, and a solid electrolyte layer positioned between the electrode layer and the counter electrode layer. The electrode layer includes a current collector, an electrode active material layer positioned between the current collector and the solid electrolyte layer, and an insulating layer positioned between the current collector and the solid electrolyte layer at an end portion of the electrode layer and joined to the current collector. The electrode active material layer has a region that does not overlap with the insulating layer in plan view. The battery has a void positioned between the current collector and the solid electrolyte layer and in contact with the insulating layer.

Effects of the Invention

[0006] According to the present disclosure, a highly reliable battery can be provided.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

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Figure 10A

Figure 10B

Figure 10C

Figure 11A

Figure 11B

Figure 12A

Figure 12B

Figure 12C

Figure 13

Figure 14

DETAILED DESCRIPTION OF THE INVENTION

[0008] (Knowledge underlying the present disclosure) When manufacturing a battery such as an all-solid-state battery including a solid electrolyte layer containing a solid electrolyte, it is common to make the area of the negative electrode active material layer larger than the area of the positive electrode active material layer. This is for the purpose of stabilizing the performance of the battery and improving the reliability of the battery by making the capacity of the negative electrode active material layer larger than the capacity of the positive electrode active material layer and suppressing the precipitation of metals derived from metal ions that have not been incorporated into the negative electrode active material layer. Also, it is an object to improve the reliability of the battery by suppressing the electric field concentration at the end of the negative electrode active material layer and suppressing dendrite growth (metal precipitation) at the end. Further, when increasing the area of the negative electrode active material layer, a solid electrolyte layer, for example, is disposed around the positive electrode active material layer arranged opposite thereto. By surrounding the positive electrode active material layer, which expands and contracts during charge and discharge, with the solid electrolyte layer, the reliability is also enhanced by suppressing the separation of the positive electrode active material layer from other layers.

[0009] However, it is difficult to manufacture a battery by precisely controlling the area of the positive electrode active material layer and the area of the negative electrode active material layer in this way. Or, in order to ensure reliability, it is necessary to form the positive electrode active material layer taking into account the dimensional accuracy during the formation of the positive electrode active material layer. Therefore, there is a problem that the positive electrode active material layer becomes small and the volume energy density of the battery decreases. Also, in order to increase the dimensional accuracy of the positive electrode active material layer, an increase in the number of processes such as inspection and an increase in equipment costs are a concern.

[0010] Therefore, the present disclosure provides a highly reliable battery. In particular, the present disclosure provides a highly reliable battery while having a high energy density.

[0011] The summary of one aspect of the present disclosure is as follows.

[0012] A battery according to one aspect of the present disclosure includes an electrode layer, a counter electrode layer disposed opposite to the electrode layer, and a solid electrolyte layer positioned between the electrode layer and the counter electrode layer. The electrode layer has a current collector, an electrode active material layer positioned between the current collector and the solid electrolyte layer, and an insulating layer positioned between the current collector and the solid electrolyte layer at an end of the electrode layer and joined to the current collector. The electrode active material layer has a region that does not overlap with the insulating layer in a plan view. The battery has a void positioned between the current collector and the solid electrolyte layer and in contact with the insulating layer.

[0013] Thereby, although the electrode active material layer of the battery expands and contracts during charge and discharge, due to the positive electrode active material layer and the void being positioned between the current collector and the solid electrolyte layer, the stress caused by the expansion and contraction of the electrode active material layer during charge and discharge can be relaxed by the void. Therefore, it becomes difficult for the electrode active material layer to cause delamination with other components. Thus, the reliability of the battery can be enhanced.

[0014] Further, the presence of the insulating layer joined to the current collector forms regions with different properties on the current collector. Therefore, a battery in which a void in contact with the insulating layer is easily formed by utilizing the difference in properties can be manufactured.

[0015] Also, for example, the side surface of the insulating layer and the side surface of the current collector may be flush.

[0016] As a result, since the side surfaces of the insulating layer and the current collector are flush, the area of the insulating layer can be easily adjusted by cutting the current collector with the insulating layer laminated thereon all at once or the like, and a battery can be manufactured. Therefore, although the presence of the insulating layer and the voids in contact with the insulating layer forms a region where the electrode active material layer hardly functions as an electrode, the area of the insulating layer can be adjusted to minimize this region. Thus, the volume energy density of the battery can be increased.

[0017] Further, for example, the electrode layer may be a positive electrode layer, and the counter electrode layer may be a negative electrode layer.

[0018] As a result, due to the insulating layer and the voids in contact with the insulating layer, the area of the electrode active material layer of the positive electrode layer, i.e., the area of the positive electrode active material layer, where electrons from the current collector easily reach, is reduced. As a result, the substantial area of the positive electrode active material layer becomes smaller than the area of the counter electrode active material layer of the negative electrode layer, i.e., the area of the negative electrode active material layer. Thus, since the capacity of the negative electrode active material layer becomes larger than the capacity of the positive electrode active material layer, the precipitation of the metal derived from the metal ions not incorporated into the negative electrode active material layer is suppressed, and the reliability of the battery can be further enhanced.

[0019] Further, even when there are no voids, in the electrode active material layer in the region overlapping the insulating layer in plan view, i.e., the positive electrode active material layer, electrons do not directly reach from the current collector, so the positive electrode active material layer in this region hardly functions as an electrode. Therefore, although the effect of substantially reducing the area of the positive electrode active material layer is obtained, by having voids in contact with the insulating layer, the intrusion of electrons between the insulating layer and the solid electrolyte layer can be further suppressed. Thus, the influence of the intrusion of electrons is reduced, and the capacity ratio between the negative electrode active material layer and the positive electrode active material layer can be more accurately adjusted.

[0020] Further, for example, the voids may further be in contact with the solid electrolyte layer.

[0021] As a result, since the voids are in contact with both the insulating layer and the solid electrolyte layer, the voids are formed across between the insulating layer and the solid electrolyte layer. Therefore, the stress from the solid electrolyte layer side is also easily relaxed by the voids.

[0022] Further, by forming a gap spanning between the insulating layer and the solid electrolyte layer, it is possible to prevent electrons from the current collector from moving between the insulating layer and the solid electrolyte layer and into the region outside the gap in plan view. Therefore, the area of the electrode active material layer that functions as an electrode is reduced, and the capacitance ratio between the negative electrode active material layer and the positive electrode active material layer can be made more accurate.

[0023] Also, for example, in plan view, the gap may overlap with the inner end portion at the joint surface between the insulating layer and the current collector.

[0024] Accordingly, when a gap is formed spanning between the insulating layer and the solid electrolyte layer, the gap is formed at a position where it is possible to prevent electrons from the current collector from moving between the insulating layer and the solid electrolyte layer and into the region outside the inner end portion at the joint surface between the insulating layer and the current collector. Therefore, the area of the electrode active material layer that functions as an electrode can be reduced in accordance with the area of the insulating layer.

[0025] Also, for example, the gap is located between the insulating layer and the solid electrolyte layer and between the insulating layer and the electrode active material layer, and the electrode active material layer and the insulating layer may not be in contact with each other.

[0026] As a result, the gap inside the battery becomes larger, and the stress caused by the expansion and contraction of the electrode active material layer during charge and discharge can be further alleviated.

[0027] Also, for example, the insulating layer may contain a resin.

[0028] Accordingly, the resin contained in the insulating layer bites into the current collector, enhancing the bonding property between the insulating layer and the current collector and suppressing the peeling between the insulating layer and the current collector.

[0029] Also, for example, the insulating layer may contain an inorganic filler.

[0030] As a result, the insulating layer becomes hard, so that when laminated with other layers during battery manufacturing, the insulating layer is less likely to deform, and an insulating layer with a uniform thickness can be formed.

[0031] Further, for example, the insulating layer may have a larger coefficient of linear expansion than the electrode active material layer.

[0032] As a result, just by heating in a state where the electrode active material layer is laminated on the insulating layer, the electrode active material layer is less likely to expand than the insulating layer, so that the electrode active material layer is separated at the position in contact with the insulating layer, and voids are formed. Therefore, a battery in which voids are formed in contact with the insulating layer can be easily manufactured.

[0033] Further, for example, the insulating layer may be located in a region where the length from the outer periphery of the current collector in plan view is 1 mm or less.

[0034] As a result, a region where the electrode active material layer hardly functions as an electrode due to the presence of the insulating layer and voids in contact with the insulating layer can be made within a range of a certain distance or less from the outer periphery of the current collector, so that the volume energy density of the battery can be increased.

[0035] Further, for example, the thickness of the insulating layer may be 50% or more and 100% or less of the thickness of the electrode active material layer.

[0036] As a result, the space between the solid electrolyte layer and the insulating layer becomes narrow, so that when forming a void between the solid electrolyte layer and the insulating layer, it can be easily formed. Further, for example, when forming the electrode active material layer using a wet coating method, the amount of slurry coated on the insulating layer is reduced, so that when forming a void by repelling the slurry due to the surface tension of the insulating layer, it becomes easier to form a void.

[0037] Further, for example, the side surfaces of the electrode layer, the counter electrode layer, and the solid electrolyte layer may be flush.

[0038] As a result, by cutting each layer all at once or the like, the side surfaces of the respective layers can be made flush, so that the area of the insulating layer can be easily adjusted to manufacture the battery.

[0039] Also, for example, the side surface of the battery may be a cut surface.

[0040] As a result, since the side surface that becomes the end of the battery is formed by cutting, by adjusting the area of the insulating layer according to the cutting position, the area of the region where the electrode active material layer hardly functions as an electrode due to the presence of the insulating layer and the voids in contact with the insulating layer can be reduced, and the volume energy density of the battery can be increased. Further, since the side surface of the battery is a cut surface, it is possible to easily make the side surfaces of the electrode layer, the counter electrode layer, and the solid electrolyte layer flush.

[0041] Also, for example, the insulating layer may be provided on the outer peripheral portion of the electrode layer and may be in a frame shape in plan view.

[0042] As a result, voids in contact with the insulating layer can be provided at any position on the outer peripheral portion of the electrode layer.

[0043] Also, for example, the solid electrolyte layer may contain a solid electrolyte having lithium ion conductivity.

[0044] As a result, in a lithium ion battery containing a solid electrolyte, the reliability of the battery can be enhanced.

[0045] Hereinafter, embodiments will be specifically described with reference to the drawings.

[0046] Note that all of the embodiments described below show comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions of the components, connection forms, and the like shown in the following embodiments are merely examples and are not intended to limit the present disclosure.

[0047] In addition, in this specification, terms indicating the relationship between elements such as parallel and flush, terms indicating the shape of elements such as flat and rectangular, and numerical ranges are not expressions representing only a strict meaning, but are expressions meaning substantially equivalent ranges, for example, including differences of about several percent.

[0048] Also, each figure is not necessarily drawn precisely. In each figure, substantially the same configuration is denoted by the same reference numeral, and overlapping descriptions are omitted or simplified.

[0049] In this specification and the drawings, the x-axis, y-axis, and z-axis indicate the three axes of a three-dimensional orthogonal coordinate system. In each embodiment, the z-axis direction is the stacking direction of the battery. Also, the positive direction of the z-axis is the upper side in the z-axis direction, and the negative direction of the z-axis is the lower side in the z-axis direction. In this specification, "plan view" means the case of viewing the battery along the z-axis. Also, "thickness" in this specification is the length in the stacking direction of each layer.

[0050] In this specification, the terms "upper" and "lower" in the configuration of the battery do not refer to the upward (vertically upward) and downward (vertically downward) directions in an absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in the stacked configuration. Also, the terms "upper" and "lower" are applicable not only when two components are spaced apart from each other and there is another component between the two components, but also when two components are arranged in close contact with each other and the two components are in contact.

[0051] In this specification, "inner" and "outer" in "inner side" and "outer side" etc. refer to the inner and outer when viewing the battery along the stacking direction in the battery. That is, the central side of each layer is the inner side, and the outer peripheral side of each layer is the outer side.

[0052] (Embodiment 1) Hereinafter, the battery according to Embodiment 1 will be described. The battery according to Embodiment 1 is a single battery including one electrode active material layer and one counter electrode active material layer respectively.

[0053] [Configuration] First, the configuration of the battery according to Embodiment 1 will be described with reference to the drawings. FIG. 1 is a schematic top view showing an example of the battery according to the present embodiment. FIG. 2 is a view showing an example of a cross section at the position indicated by line II-II in FIG. 1.

[0054] As shown in FIGS. 1 and 2, the battery 50 according to the present embodiment includes an electrode layer 10, a counter electrode layer 20 disposed to face the electrode layer 10, and a solid electrolyte layer 30 positioned between the electrode layer 10 and the counter electrode layer 20. That is, the battery 50 has a structure in which the electrode layer 10, the solid electrolyte layer 30, and the counter electrode layer 20 are laminated in this order.

[0055] The electrode layer 10 has a current collector 11, an electrode active material layer 12 positioned between the current collector 11 and the solid electrolyte layer 30, and an insulating layer 13 positioned between the current collector 11 and the solid electrolyte layer 30 at the end of the electrode layer 10 in plan view and joined to the current collector 11. The electrode active material layer 12 is composed of an electrode active material layer 12a and an electrode active material layer 12b spaced apart through a void 14 described later. In the illustrated example, the insulating layer 13 is in contact with the current collector 11, but may be joined to the current collector 11 via an adhesive layer or the like.

[0056] The counter electrode layer 20 has a current collector 21 and a counter electrode active material layer 22 positioned between the current collector 21 and the solid electrolyte layer 30.

[0057] Further, the battery 50 has a void 14 positioned between the current collector 11 and the solid electrolyte layer 30 and in contact with the insulating layer 13. That is, the battery 50 is provided with a void 14 positioned between the current collector 11 and the solid electrolyte layer 30 and exposing the insulating layer 13.

[0058] The battery 50 is, for example, an all-solid-state battery. The side surface of the battery 50 is parallel to the stacking direction. Also, the side surface of the battery 50 is a flat plane. In other words, the side surfaces of the electrode layer 10, the counter electrode layer 20, and the solid electrolyte layer 30 are in a state without a step and are located on the same flat plane. That is, the side surfaces of the electrode layer 10, the counter electrode layer 20, and the solid electrolyte layer 30 are flush. Here, the side surface is, in each component of the battery 50, a surface that extends in a direction intersecting the main surface when the plane perpendicular to the stacking direction is taken as the main surface. Also, at the end in the direction perpendicular to the stacking direction of the electrode layer 10, the side surfaces of the insulating layer 13, the electrode active material layer 12b, and the current collector 11 are flush. Also, at the end in the direction perpendicular to the stacking direction of the counter electrode layer 20, the side surfaces of the counter electrode active material layer 22 and the current collector 21 are flush. That is, at the end in the direction perpendicular to the stacking direction of the battery 50, the side surfaces of the current collector 11, the insulating layer 13, the electrode active material layer 12b, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 are flush and form the same flat plane. Thereby, since the side surfaces of the respective layers can be made flush by cutting the respective layers all at once, etc., the area of the insulating layer 13 and the electrode active material layer 12b can be easily adjusted to manufacture the battery 50.

[0059] The side surface of the battery 50 is, for example, a cut surface. Specifically, the side surface of the battery 50 is a surface formed by being cut with a blade such as a cutter, and is, for example, a surface having a cutting mark such as a fine groove. In this way, since the cut surface formed by cutting the battery 50 is formed, the position where the insulating layer 13 and the electrode active material layer 12b are formed can be adjusted, so the area of the portion that does not contribute to the charge and discharge performance of the battery 50 (specifically, the portion where the electrode active material layer 12b and the void 14 are located in plan view, details will be described later) can be reduced, and the volume energy density can be improved. Also, by being a cut surface, it is possible to easily make the side surfaces of the electrode layer 10, the counter electrode layer 20, and the solid electrolyte layer 30 flush. Note that the cutting mark may be smoothed by polishing or the like. The shape of the cut surface is not limited, but in the case of the battery 50, it is rectangular.

[0060] In addition, although the plan view shapes of the current collector 11, the electrode active material layer 12a, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 are rectangular, they are not particularly limited and may be circular, elliptical, polygonal, or the like.

[0061] The current collector 11 is in contact with the lower surfaces of the electrode active material layer 12 (specifically, the electrode active material layer 12a) and the insulating layer 13, and covers the lower surfaces of the electrode active material layer 12 and the insulating layer 13. The insulating layer 13 is laminated on the end portion of the current collector 11 in plan view, and the gap 14 is in contact with the insulating layer 13. The thickness of the current collector 11 is, for example, 5 μm or more and 100 μm or less.

[0062] As the material of the current collector 11, known materials can be used. For the current collector 11, for example, a foil-like body, a plate-like body, a mesh-like body, etc. made of copper, aluminum, nickel, iron, stainless steel, platinum, gold, or an alloy of two or more of these are used.

[0063] The upper surfaces of the electrode active material layers 12a and 12b are in contact with the solid electrolyte layer 30. The electrode active material layers 12a and 12b and the counter electrode active material layer 22 face each other with the solid electrolyte layer 30 interposed therebetween. The lower surface of the electrode active material layer 12a is in contact with the current collector 11. The electrode active material layer 12b is frame-shaped in plan view and surrounds the electrode active material layer 12a. The electrode active material layer 12b is laminated above the current collector 11 so as to cover the insulating layer 13 on the current collector 11. The electrode active material layer 12 has a region that does not overlap with the insulating layer 13 in plan view. Specifically, in plan view, the electrode active material layer 12a does not overlap with the insulating layer 13, and the electrode active material layer 12b overlaps with the insulating layer 13. The thickness of the electrode active material layer 12a is, for example, 5 μm or more and 300 μm or less. The material used for the electrode active material layer 12 will be described later.

[0064] Note that the electrode active material layer 12a and the electrode active material layer 12b are not in contact with each other at all and are completely separated, but a part of them may be connected.

[0065] As described above, the insulating layer 13 is in contact with the void 14 and is located between the current collector 11 and the solid electrolyte layer 30. The upper surface of the insulating layer 13 is in contact with the electrode active material layer 12b and the void 14, and the inner side surface of the insulating layer 13 in plan view is in contact with the electrode active material layer 12a. The insulating layer 13 is in contact with the electrode active material layer 12b at the end of the electrode layer 10 in plan view. The side surface of the insulating layer 13 and the side surface of the current collector 11 are flush. Also, the side surface of the insulating layer 13 and the side surface of the electrode active material layer 12 (specifically, the electrode active material layer 12b) are flush. The lower surface of the insulating layer 13 is in contact with the current collector 11. Also, the insulating layer 13 overlaps with the counter electrode active material layer 22 in plan view.

[0066] In the illustrated example, the insulating layer 13 is located at the outer peripheral portion of the electrode layer 10 in plan view and is frame-shaped. That is, the insulating layer 13 is located between the current collector 11 and the solid electrolyte layer 30 at all ends in the direction perpendicular to the stacking direction of the electrode layer 10.

[0067] The insulating layer 13 contains at least one of, for example, a resin and an inorganic filler. Examples of the resin include silicone resin, epoxy resin, acrylic resin, polyimide resin, etc. The resin may be a thermosetting resin or an ultraviolet curable resin. By the insulating layer 13 containing the resin, the bonding property between the insulating layer 13 and the current collector 11 can be enhanced by an anchor effect or the like in which the resin bites into the current collector 11. Also, by adjusting the surface tension of the resin, for example, when forming the electrode active material layer using a wet coating method, an insulating layer 13 having a surface tension that repels the slurry containing the electrode active material can be formed, and the void 14 can be easily formed. Examples of the inorganic filler include particles of metal oxides such as silicon oxide, titanium oxide, aluminum oxide, and aluminum nitride. By the insulating layer 13 containing the inorganic filler, the insulating layer 13 becomes hard, so the insulating layer 13 is less likely to be deformed when laminated with other layers, and an insulating layer 13 having a uniform thickness can be formed. Also, by selecting a material having a larger linear expansion coefficient than the electrode active material layer 12 as the material of the insulating layer 13, the void 14 can be easily formed by heat treatment or the like. Details of the method for forming the void 14 will be described later.

[0068] The thickness of the insulating layer 13 is equal to or less than the thickness of the electrode active material layer 12a in the electrode active material layer 12. The thickness of the insulating layer 13 is, for example, 50% or more and 100% or less of the thickness of the electrode active material layer 12a. Further, the thickness of the insulating layer 13 may be 50% or more and less than 100% of the thickness of the electrode active material layer 12a. Thereby, for example, when forming the electrode active material layer 12 using a wet coating method, a slurry is applied onto the current collector 11 and the insulating layer 13, but the amount of slurry applied onto the insulating layer 13 is reduced. Therefore, when forming the void 14 by repelling the slurry due to the surface tension of the insulating layer 13, the void 14 is likely to be formed. Further, when forming the void 14 due to the difference in the linear expansion coefficients between the insulating layer 13 and the electrode active material layer 12, since the electrode active material layer 12 on the insulating layer 13 is thin, the void 14 is likely to be formed.

[0069] The insulating layer 13 is, for example, completely insulating, but depending on the required battery characteristics, it may have slightly conductivity depending on the constituent material and thickness of the insulating layer 13.

[0070] Further, from the viewpoint of the effective area contributing to power generation, that is, from the viewpoint of the volume energy density, the insulating layer 13 is located, for example, in a region where the length from the outer periphery of the current collector 11 is 1 mm or less in a plan view. Further, when the insulating layer 13 is formed in a frame shape, a line shape, or the like, the width of the insulating layer 13 is, from the viewpoint of the volume energy density, for example, 1 mm or less, may be 0.5 mm or less, and may be 0.1 mm or less. The width of the insulating layer 13 is changed, for example, depending on the required battery characteristics.

[0071] The void 14 is located between the current collector 11 and the solid electrolyte layer 30. Also, the void 14 is located between the insulating layer 13 and the solid electrolyte layer 30 and is in contact with the insulating layer 13. Specifically, the void 14 is in contact with the upper surface of the insulating layer 13. Further, the void 14 is also in contact with the solid electrolyte layer 30. The void 14 extends between the insulating layer 13 and the solid electrolyte layer 30, exposing the insulating layer 13 and the solid electrolyte layer 30. Therefore, the void 14 divides the electrode active material layer 12 into an electrode active material layer 12a and an electrode active material layer 12b. That is, the void 14 is located between the electrode active material layer 12a and the electrode active material layer 12b. As a result, the presence of the void 14 can prevent the intrusion of electricity into the electrode active material layer 12b. Therefore, the electrode active material layer 12b located above the insulating layer 13 does not contribute to the charge and discharge performance, and the capacitance ratio between the electrode active material layer 12 and the counter electrode active material layer 22 can be made more accurate.

[0072] Also, in plan view, the void 14 overlaps with the inner end 13b of the joint surface 13a between the insulating layer 13 and the current collector 11. Thereby, the void 14 is formed at a position where the movement of electrons from the current collector 11 can be prevented to the region between the insulating layer 13 and the solid electrolyte layer 30 and to the region outside the inner end 13b of the joint surface 13a between the insulating layer 13 and the current collector 11. Thus, the area of the electrode active material layer 12 that functions as an electrode can be reduced in accordance with the area of the insulating layer 13.

[0073] Also, in plan view, the void 14 is provided along the longitudinal direction of the insulating layer 13. Therefore, in plan view, the void 14 is in a frame shape and is formed over the entire circumference along the circumferential direction of the frame-shaped insulating layer 13. Specifically, the void 14 is formed at a position overlapping the insulating layer 13 along the inner circumference of the frame-shaped insulating layer 13 in plan view. The void 14 is not formed inside the insulating layer 13 in plan view. As a result, the outside of the region 1B (details will be described later), which is a region where the electrode active material layer 12 does not function as a battery, becomes the same as the region where the insulating layer 13 is formed. Therefore, the region where the battery does not function does not spread beyond the region where the insulating layer 13 is formed, and the volume energy density of the battery 50 can be increased.

[0074] Further, from the viewpoint of suppressing a decrease in the volume energy density, the void 14 is located, for example, in a region where the length from the outer periphery of the current collector 11 is 1.5 mm or less in a plan view. The void 14 may be located in a region where the length from the outer periphery of the current collector 11 is 1 mm or less in a plan view, or may be located in a region where the length is 0.5 mm or less.

[0075] The current collector 21 is in contact with the upper surface of the counter electrode active material layer 22 and covers the upper surface of the counter electrode active material layer 22. The thickness of the current collector 21 is, for example, 5 μm or more and 100 μm or less. As the material of the current collector 21, the material of the above-described current collector 11 can be used.

[0076] The counter electrode active material layer 22 is laminated on the solid electrolyte layer 30 and is disposed to face the electrode active material layer 12 (specifically, the electrode active material layers 12a and 12b). The upper surface of the counter electrode active material layer 22 is in contact with the current collector 21. The thickness of the counter electrode active material layer 22 is, for example, 5 μm or more and 300 μm or less. The material used for the counter electrode active material layer 22 will be described later.

[0077] The solid electrolyte layer 30 is located between the electrode active material layer 12 and the counter electrode active material layer 22. The thickness of the solid electrolyte layer 30 is, for example, 5 μm or more and 150 μm or less.

[0078] The solid electrolyte layer 30 contains at least a solid electrolyte and may contain a binder material as necessary. The solid electrolyte layer 30 may contain a solid electrolyte having lithium ion conductivity.

[0079] As the solid electrolyte, a material that conducts known metal ions such as a lithium ion conductor, a sodium ion conductor, or a magnesium ion conductor can be used. As the solid electrolyte, for example, a solid electrolyte material such as a sulfide solid electrolyte, a halogen-based solid electrolyte, or an oxide solid electrolyte is used. In the case of a material that can conduct lithium ions as the sulfide solid electrolyte, for example, lithium sulfide (Li 2 S) and phosphorus pentasulfide (P 2 S 5A composite material consisting of 2 S - SiS 2 Li 2 S - B 2 S 3 or Li 2 S - GeS 2 etc. may be used as the sulfide solid electrolyte. As additives to the above sulfide, at least one of Li 3 N, LiCl, LiBr, Li 3 PO 4 and Li 4 SiO 4 may be added and the resulting sulfide may be used.

[0080] As the oxide solid electrolyte, in the case of a material capable of conducting lithium ions, for example, Li 7 La 3 Zr 2 O 12 (LLZ), Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP) or (La,Li)TiO 3 (LLTO), etc. are used.

[0081] As the binder material, for example, elastomers are used, and organic compounds such as polyvinylidene fluoride, acrylic resin, or cellulose resin may also be used.

[0082] In this embodiment, among the electrode layer 10 having the electrode active material layer 12 and the counter electrode layer 20 having the counter electrode active material layer 22, one is the positive electrode layer having the positive electrode active material layer, and the other is the negative electrode layer having the negative electrode active material layer.

[0083] The positive electrode active material layer contains at least a positive electrode active material, and may optionally contain at least one of a solid electrolyte, a conductive assistant, and a binder material.

[0084] As the positive electrode active material, known materials capable of occluding and releasing (inserting and extracting, or dissolving and precipitating) lithium ions, sodium ions, or magnesium ions can be used. In the case of a material capable of detaching and inserting lithium ions as the positive electrode active material, for example, lithium cobalt composite oxide (LCO), lithium nickel composite oxide (LNO), lithium manganese composite oxide (LMO), lithium-manganese-nickel composite oxide (LMNO), lithium-manganese-cobalt composite oxide (LMCO), lithium-nickel-cobalt composite oxide (LNCO), or lithium-nickel-manganese-cobalt composite oxide (LNMCO) is used.

[0085] As the solid electrolyte, the above-described solid electrolyte materials can be used. As the conductive assistant, for example, conductive materials such as acetylene black, carbon black, graphite, or carbon fiber are used. As the binder material, the above-described binder materials can be used.

[0086] The negative electrode active material layer contains at least a negative electrode active material, and may contain at least one of the same solid electrolyte, conductive assistant, and binder material as the positive electrode active material layer, if necessary.

[0087] As the negative electrode active material, known materials capable of occluding and releasing (inserting and extracting, or dissolving and precipitating) lithium ions, sodium ions, or magnesium ions can be used. In the case of a material capable of detaching and inserting lithium ions as the negative electrode active material, for example, carbon materials such as natural graphite, artificial graphite, graphite carbon fiber, or resin-fired carbon, metallic lithium, lithium alloy, or oxides of lithium and transition metal elements are used.

[0088] When manufacturing a battery, as described above, for the purpose of improving reliability, it is common to make the area of the negative electrode active material layer larger than the area of the positive electrode active material layer in plan view. Further, by disposing the end portion of the negative electrode active material layer outside the end portion of the positive electrode active material layer, the electric field concentration at the end portion of the negative electrode active material layer can be suppressed, and dendrite growth (metal deposition) can be suppressed.

[0089] Here, batteries 950 and 950a according to a comparative example in which the area of the negative electrode active material layer is larger than the area of the positive electrode active material layer in plan view will be described. FIGS. 3 and 4 are schematic cross-sectional views showing examples of the batteries according to the comparative example.

[0090] As shown in FIG. 3, the battery 950 includes a positive electrode layer 910, a negative electrode layer 920, and a solid electrolyte layer 930 positioned between the positive electrode layer 910 and the negative electrode layer 920. The positive electrode layer 910 has a current collector 911 and a positive electrode active material layer 912 positioned between the current collector 911 and the solid electrolyte layer 930. The negative electrode layer 920 has a current collector 921 and a negative electrode active material layer 922 positioned between the current collector 921 and the solid electrolyte layer 930. The solid electrolyte layer 930 covers the side surfaces of the positive electrode active material layer 912 and the negative electrode active material layer 922 and is in contact with the current collector 911 and the current collector 921. In the battery 950, in plan view, the area of the negative electrode active material layer 922 is larger than the area of the positive electrode active material layer 912, and the end portion of the negative electrode active material layer 922 is positioned outside the end portion of the positive electrode active material layer 912. Thus, in the battery 950, by making the area of the negative electrode active material layer 922 larger than the area of the positive electrode active material layer 912, metal deposition is suppressed. Further, since the solid electrolyte layer 930 exists at the end portion of the battery 950, even when the current collectors 911 and 921 are peeled off from the end portion, exposure of the positive electrode active material layer 912 and the negative electrode active material layer 922 is suppressed.

[0091] The region 2C where the positive electrode active material layer 912 and the negative electrode active material layer 922 are present functions as a battery. On the other hand, the region 2A where neither the positive electrode active material layer 912 nor the negative electrode active material layer 922 is present does not function as a battery. Also, the region 2B where the negative electrode active material layer 922 is present but the positive electrode active material layer 912 is not present does not function as a battery. The region 2B is a region corresponding to the area difference between the positive electrode active material layer 912 and the negative electrode active material layer 922. The wider the regions 2B and 2A are in plan view, the higher the proportion of the region that does not contribute to power generation in the battery 950 becomes, and the lower the volume energy density of the battery 950 decreases. On the other hand, the narrower the region 2B is in plan view, the higher the alignment accuracy required in the manufacturing process such as the process of laminating each layer becomes, and there is a concern about an increase in the number of processes such as inspection and an increase in equipment costs due to the higher required accuracy.

[0092] That is, in the battery 950, there is a problem that it is difficult to easily manufacture the battery 950. Also, in the region 2A where the layer in the thickness direction is only the solid electrolyte layer 930, it is a portion that does not particularly contribute to the basic charge and discharge performance of the battery. Therefore, from the viewpoint of improving the volume energy density, it is preferable that the region 2A is small.

[0093] Also, the battery 950a shown in FIG. 4 includes a positive electrode layer 910a having a current collector 911a and a positive electrode active material layer 912a, a negative electrode layer 920a having a current collector 921a and a negative electrode active material layer 922a, and a solid electrolyte layer 930a. The battery 950a is different from the battery 950 in that the solid electrolyte layer 930a does not cover the side surface of the negative electrode active material layer 922a. Although the battery 950a does not have a region where neither the positive electrode active material layer 912 nor the negative electrode active material layer 922 is present like the region 2A, it has a region 3A where the positive electrode active material layer 912a is not present. Therefore, the region 3A does not contribute to power generation, and the same problem as that of the region 2B occurs in the region 3A of the battery 950a.

[0094] On the one hand, as described above, the battery 50 includes the electrode layer 10, the counter electrode layer 20 disposed opposite to the electrode layer 10, and the solid electrolyte layer 30 located between the electrode layer 10 and the counter electrode layer 20. The electrode layer 10 has a current collector 11, an electrode active material layer 12 located between the current collector 11 and the solid electrolyte layer 30, and an insulating layer 13 located between the current collector 11 and the electrode active material layer 12 at the end of the electrode layer 10 in plan view. Further, the battery 50 has a void 14 that contacts the insulating layer 13 and divides the electrode active material layer 12 into an electrode active material layer 12a and an electrode active material layer 12b. The side surface of the insulating layer 13 and the side surface of the current collector 11 are flush. Furthermore, the side surfaces of the current collector 11, the insulating layer 13, the electrode active material layer 12b in the electrode active material layer 12, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 are flush.

[0095] As a result, although the electrode active material layer 12 of the battery 50 expands and contracts during charge and discharge, since the electrode active material layer 12 and the void 14 are located between the current collector 11 and the solid electrolyte layer 30, the stress caused by the expansion and contraction of the electrode active material layer 12 can be relaxed by the void 14. Therefore, it becomes difficult for the electrode active material layer 12 to cause delamination from other components. Thus, the reliability of the battery 50 is improved.

[0096] In addition, since the insulating layer 13 made of a material different from that of the current collector 11 is formed on the current collector 11, the void 14 in contact with the insulating layer 13 can be easily formed by utilizing the differences in the properties of the materials of the current collector 11, the electrode active material layer 12, and the insulating layer 13.

[0097] Also, since the insulating layer 13 exists between the current collector 11 and the electrode active material layer 12b at the end of the current collector 11 where peeling is likely to occur, even if the current collector 11 peels off, the exposure of the electrode active material layer 12b is suppressed, and damage or short circuit caused by contact between the electrode active material layer 12b and other members is less likely to occur. Thus, the reliability of the battery 50 is improved.

[0098] In addition, since the side surfaces of the current collector 11, the insulating layer 13, the electrode active material layer 12b, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 are flush, the battery 50 can be easily manufactured by adjusting the area of the insulating layer 13 by cutting these layers together, etc. Therefore, although the electrode active material layer 12b does not function as an electrode due to the presence of the gap 14 in contact with the insulating layer 13, the area of the insulating layer can be adjusted to minimize this region. Thus, the volumetric energy density of the battery can be increased.

[0099] In the battery 50, for example, the electrode layer 10 having the electrode active material layer 12 is a positive electrode layer having a positive electrode active material layer, and the counter electrode layer 20 having the counter electrode active material layer 22 is a negative electrode layer having a negative electrode active material layer. In this case, since there is a gap 14 in the positive electrode active material layer (the electrode active material layer 12b in the electrode active material layer 12) located above the insulating layer 13, electrons cannot reach directly from the current collector 11, so the positive electrode active material layer in the region 1A outside the region 1B shown in FIGS. 1 and 2 does not function as an electrode. Even if only the insulating layer 13 is present, it becomes difficult for electrons to reach the positive electrode active material layer located above the insulating layer 13, but the presence of the gap 14 can further inhibit the movement of electrons. On the other hand, the positive electrode active material layer in the region 1B functions as an electrode. Therefore, in the battery 50, the region outside the region 1B including the region 1A does not function as a battery, and the region 1B functions as a battery. In the battery 50, although the areas of the positive electrode active material layer and the negative electrode active material layer (the counter electrode active material layer 22) in plan view are the same, since the positive electrode active material layer outside the region 1B does not function as an electrode, the area of the positive electrode active material layer in plan view is substantially reduced.

[0100] In addition, since the positive electrode active material layer (that is, the electrode active material layer 12b) at the position facing the end of the negative electrode active material layer does not function as an electrode, the electric field concentration at the end of the negative electrode active material layer is suppressed, and the dendrite growth at the end is suppressed. Thus, the reliability of the battery 50 is improved.

[0101] Furthermore, in the manufacture of the battery 50, since the area of the substantial positive electrode active material layer can be adjusted by the void 14 in contact with the insulating layer 13, it is not necessary to accurately form the positions and areas of the positive electrode active material layer and the negative electrode active material layer. Therefore, the battery 50 can be easily manufactured. For example, the battery 50 can be easily manufactured by cutting a laminate in which a positive electrode layer (electrode layer 10), a solid electrolyte layer 30, and a negative electrode layer (counter electrode layer 20) are laminated in a region including the insulating layer 13.

[0102] [Modification Example 1] Hereinafter, Modification Example 1 of Embodiment 1 will be described. In the description of Modification Example 1 below, the description will focus on the differences from Embodiment 1, and the description of the common points will be omitted or simplified.

[0103] FIG. 5 is a schematic cross-sectional view showing an example of the battery according to this modification. In FIG. 5, a cross-section of the battery 50a at the same position as in FIG. 2 is shown. As shown in FIG. 5, the battery 50a according to this modification is different from the battery 50 in Embodiment 1 in that it has a void 14a instead of the void 14.

[0104] The battery 50a according to this modification includes an electrode layer 10a, a counter electrode layer 20 disposed to face the electrode layer 10a, and a solid electrolyte layer 30 positioned between the electrode layer 10a and the counter electrode layer 20. Further, the battery 50a has a void 14a that is located between the current collector 11 and the solid electrolyte layer 30 and is in contact with the insulating layer 13.

[0105] The electrode layer 10a has a current collector 11, an electrode active material layer 12c positioned between the current collector 11 and the solid electrolyte layer 30, and an insulating layer 13 that is positioned between the current collector 11 and the solid electrolyte layer 30 at the end of the electrode layer 10 in plan view and is joined to the current collector 11. The electrode active material layer 12c is composed of an electrode active material layer 12d and an electrode active material layer 12e that are separated via the void 14a.

[0106] The electrode active material layer 12c has a region that does not overlap with the insulating layer 13 in plan view. Specifically, in plan view, the electrode active material layer 12d does not overlap with the insulating layer 13, and the electrode active material layer 12e completely overlaps with the insulating layer 13 and has the same shape and position.

[0107] The void 14a is located between the insulating layer 13 and the electrode active material layer 12d and is in contact with the insulating layer 13. Specifically, the void 14a is in contact with the inner side surface of the insulating layer 13. The void 14a is further in contact with the current collector 11 and the solid electrolyte layer 30. The void 14a extends between the current collector 11 and the solid electrolyte layer 30 and exposes the current collector 11, the insulating layer 13, and the solid electrolyte layer 30. As a result, since the area of contact between the void 14a and the electrode active material layer 12c increases, the stress caused by the expansion and contraction of the electrode active material layer 12c during charge and discharge can be further relaxed.

[0108] Also, in plan view, the void 14a overlaps with the inner end 13b of the joint surface 13a between the insulating layer 13 and the current collector 11. The void 14a is formed inward along the inner side surface of the insulating layer 13 from the inner side surface of the insulating layer 13 in plan view.

[0109] Thus, also in the battery 50a according to this modification, the stress during the expansion and contraction of the electrode active material layer 12c is relaxed due to the presence of the void 14a, and the region outside the region 1B including the region 1A does not function as a battery, and the region 1B functions as a battery, etc., so that the same effect of improving the reliability as that of the battery 50 can be obtained.

[0110] [Modification 2] Hereinafter, Modification 2 of Embodiment 1 will be described. In the following description of Modification 2, the description will focus on the differences from Embodiment 1, and the description of the common points will be omitted or simplified.

[0111] FIG. 6 is a schematic cross-sectional view showing an example of the battery according to this modified example. In FIG. 6, a cross-section of the battery 50b at the same position as in FIG. 2 is shown. As shown in FIG. 6, the battery 50b according to this modified example is different from the battery 50 in Embodiment 1 in that it has a void 14b instead of the void 14.

[0112] The battery 50b according to this modified example includes an electrode layer 10b, a counter electrode layer 20 disposed to face the electrode layer 10b, and a solid electrolyte layer 30 positioned between the electrode layer 10b and the counter electrode layer 20. Further, the battery 50b has a void 14b that is located between the current collector 11 and the solid electrolyte layer 30 and is in contact with the insulating layer 13.

[0113] The electrode layer 10b has a current collector 11, an electrode active material layer 12f positioned between the current collector 11 and the solid electrolyte layer 30, and an insulating layer 13 that is located between the current collector 11 and the solid electrolyte layer 30 at the end of the electrode layer 10 in plan view and is joined to the current collector 11. The electrode active material layer 12f is composed of an electrode active material layer 12g and an electrode active material layer 12h that are separated via the void 14b.

[0114] The electrode active material layer 12f has a region that does not overlap with the insulating layer 13 in plan view. Specifically, in plan view, the electrode active material layer 12g does not overlap with the insulating layer 13, and the electrode active material layer 12h overlaps with the insulating layer 13.

[0115] The void 14b is located between the insulating layer 13 and the solid electrolyte layer 30 and between the insulating layer 13 and the electrode active material layer 12g, and is in contact with the insulating layer 13. Specifically, the void 14b is in contact with the upper surface of the insulating layer 13 and the inner side surface of the insulating layer 13. Further, the void 14b is also in contact with the current collector 11 and the solid electrolyte layer 30. The void 14b extends between the insulating layer 13 and the solid electrolyte layer 30 and between the current collector 11 and the solid electrolyte layer 30, exposing the current collector 11, the insulating layer 13, and the solid electrolyte layer 30.

[0116] Also, in plan view, the void 14b overlaps with the inner end 13b of the joint surface 13a between the insulating layer 13 and the current collector 11.

[0117] Thus, also in the battery 50b according to this modification example, the presence of the void 14b relaxes the stress during the expansion and contraction of the electrode active material layer 12f, and the region outside the region 1B including the region 1A does not function as a battery, and the region 1B functions as a battery. As a result, an effect similar to that of the battery 50 in improving reliability can be obtained.

[0118] [Modification Example 3] Hereinafter, Modification Example 3 of Embodiment 1 will be described. In the following description of Modification Example 3, the differences from Embodiment 1 will be mainly described, and the description of the common points will be omitted or simplified.

[0119] FIG. 7 is a schematic cross-sectional view showing an example of the battery according to this modification example. In FIG. 7, a cross-section of the battery 50c at the same position as in FIG. 2 is shown. As shown in FIG. 7, the battery 50c according to this modification example is different from the battery 50 in Embodiment 1 in that it has a void 14c instead of the void 14.

[0120] The battery 50c according to this modification example includes an electrode layer 10c, a counter electrode layer 20 disposed opposite to the electrode layer 10c, and a solid electrolyte layer 30 positioned between the electrode layer 10c and the counter electrode layer 20. Further, the battery 50c has a void 14c that is located between the current collector 11 and the solid electrolyte layer 30 and is in contact with the insulating layer 13.

[0121] The electrode layer 10c has a current collector 11, an electrode active material layer 12i positioned between the current collector 11 and the solid electrolyte layer 30, and an insulating layer 13 that is located between the current collector 11 and the solid electrolyte layer 30 at the end of the electrode layer 10 in plan view and is joined to the current collector 11.

[0122] The lower surface of the electrode active material layer 12i is in contact with the current collector 11. Also, the electrode active material layer 12i and the insulating layer 13 are not in contact with each other.

[0123] The gap 14c is located between the insulating layer 13 and the solid electrolyte layer 30, and between the insulating layer 13 and the electrode active material layer 12i, and is in contact with the insulating layer 13. Specifically, the gap 14c is in contact with the upper surface of the insulating layer 13 and the entire inner side surface of the insulating layer 13. That is, the gap 14c exposes the entire upper surface and the inner side surface of the insulating layer 13, and the electrode active material layer 12i and the insulating layer 13 are not in contact. Thereby, the gap in the battery 50c becomes larger, and the stress of the expansion and contraction of the electrode active material layer 12i during charge and discharge can be further relaxed.

[0124] Further, in plan view, the gap 14c overlaps with the inner end portion 13b of the joint surface 13a between the insulating layer 13 and the current collector 11.

[0125] Thus, also in the battery 50c according to this modification example, the stress during the expansion and contraction of the electrode active material layer 12i is relaxed due to the presence of the gap 14c, and the region outside the region 1B does not function as a battery, and the region 1B functions as a battery, etc., so that the same effect of improving the reliability as that of the battery 50 can be obtained.

[0126] [Modification Example 4] Hereinafter, Modification Example 4 of Embodiment 1 will be described. In the following description of Modification Example 4, the description will focus on the differences from Embodiment 1, and the description of the common points will be omitted or simplified.

[0127] FIG. 8 is a schematic cross-sectional view showing an example of the battery according to this modification example. In FIG. 8, a cross-section of the battery 50d at the same position as in FIG. 2 is shown. As shown in FIG. 8, the battery 50d according to this modification example is different from the battery 50 in Embodiment 1 in that it has a gap 14d instead of the gap 14.

[0128] The battery 50d according to this modification example includes an electrode layer 10d, a counter electrode layer 20 disposed opposite to the electrode layer 10d, and a solid electrolyte layer 30 located between the electrode layer 10d and the counter electrode layer 20. Further, the battery 50d has a gap 14d located between the current collector 11 and the solid electrolyte layer 30 and in contact with the insulating layer 13.

[0129] The electrode layer 10d has a current collector 11, an electrode active material layer 12j positioned between the current collector 11 and the solid electrolyte layer 30, and an insulating layer 13 positioned between the current collector 11 and the solid electrolyte layer 30 and joined to the current collector 11 at the end of the electrode layer 10 in plan view. The electrode active material layer 12j is composed of an electrode active material layer 12k and an electrode active material layer 12l that are spaced apart via a void 14d.

[0130] The lower surface of the electrode active material layer 12k is in contact with the current collector 11. Also, the electrode active material layer 12k is in contact with a part of the upper surface of the insulating layer 13 and the side surface of the insulating layer 13. The electrode active material layer 12l is in a frame shape in plan view and surrounds the electrode active material layer 12k. A part of the electrode active material layer 12k and the electrode active material layer 12l are laminated above the current collector 11 so as to cover the insulating layer 13 on the current collector 11. The electrode active material layer 12j has a region that does not overlap with the insulating layer 13 in plan view. Specifically, in plan view, a part of the electrode active material layer 12k does not overlap with the insulating layer 13, and the electrode active material layer 12l overlaps with the insulating layer 13.

[0131] The void 14d is positioned between the insulating layer 13 and the solid electrolyte layer 30 and is in contact with the insulating layer 13. Also, the void 14d is formed at a position overlapping with the insulating layer 13 along the direction in which the frame-shaped insulating layer 13 extends in plan view.

[0132] Thus, also in the battery 50d according to this modification example, the presence of the void 14d relaxes the stress during expansion and contraction of the electrode active material layer 12k, and the region outside the region 1B including the region 1A does not function as a battery, and the region 1B functions as a battery, etc., so that the same effect of improving reliability as that of the battery 50 is obtained.

[0133] [Manufacturing method] Next, a manufacturing method of the battery according to the present embodiment will be described. Hereinafter, the manufacturing method of the battery 50 according to the above-described Embodiment 1 will be mainly described. The other batteries 50a, 50b, 50c, and 50d can also be manufactured by the same method. Note that the manufacturing method of the battery 50 described below is an example, and the manufacturing method of the battery 50 is not limited to the following example.

[0134] The manufacturing method of the battery 50 includes an insulating layer laminating step, a power generation element laminating step, a cutting step, and a current collector laminating step. Hereinafter, each step will be described in detail.

[0135] (1) Insulating layer laminating step First, the insulating layer laminating step will be described. FIG. 9 is a flowchart for explaining the manufacturing method of the battery according to the present embodiment.

[0136] In the insulating layer laminating step, the insulating layer 13 is laminated on at least one surface of the current collector 11. Specifically, first, the current collector 11 is prepared (step S11 in FIG. 9). Then, the insulating layer 13 is laminated on at least one surface of the prepared current collector 11 (step S12 in FIG. 9). For example, the insulating layer 13 is laminated on the current collector 11 by forming the insulating layer 13 on the upper surface of the current collector 11.

[0137] FIG. 10A, FIG. 10B, and FIG. 10C are schematic diagrams showing examples of the current collector 11 with the insulating layer 13 laminated thereon. (a) of FIG. 10A is a schematic top view showing an example of the current collector 11 with the insulating layer 13 laminated thereon, and (b) of FIG. 10A is a schematic cross-sectional view at the position indicated by the line Xa(b)-Xa(b) in (a) of FIG. 10A. The insulating layer 13 is formed in a lattice shape, for example, as shown in FIG. 10A. Further, FIG. 10B is a schematic top view showing another example of the current collector 11 with the insulating layer 13 laminated thereon. Although a cross-sectional view is not shown in FIG. 10B, the current collector 11 with the insulating layer 13 laminated thereon shown in FIG. 10B has the same cross-sectional structure as (b) of FIG. 10A. The insulating layer 13 may be formed in a stripe shape as shown in FIG. 10B. By laminating the insulating layer 13 in a relatively simple planar shape having a long portion such as a lattice or a stripe, the insulating layer 13 can be easily formed on the current collector 11. Further, in the cutting step described later, by dividing the insulating layer 13 along the long direction of the insulating layer 13, the battery 50 with the insulating layer 13 formed along the end of the battery 50 can be easily formed. In FIGS. 10A and 6B, the rectangular regions 1E and 1F described by the dotted lines correspond to the size of one battery 50. Thus, the current collector 11 may have the insulating layer 13 laminated thereon so that it can be divided into a plurality of batteries in a later manufacturing process.

[0138] Further, (a) of FIG. 10C is a schematic top view showing still another example of the current collector 11 with the insulating layer 13 laminated thereon, and (b) of FIG. 10C is a schematic cross-sectional view at the position indicated by the line Xc(b)-Xc(b) in (a) of FIG. 10C. As shown in FIG. 10C, a lattice-shaped insulating layer 13 of a plurality of types of patterns (for example, lattice intervals) may be formed on the current collector 11.

[0139] Thus, by laminating the insulating layer 13 in a lattice shape or a stripe shape and dividing the insulating layer 13 along the long direction of the lattice or stripe of the insulating layer 13 in the cutting step described later, a plurality of batteries 50 having the same shape or different shapes can be manufactured simultaneously. Thereby, the manufacturing efficiency of the battery 50 is improved.

[0140] Regarding the method of forming the insulating layer 13, various processes can be considered. From the perspective of mass productivity, for example, a coating process is used. For example, in a continuous process such as a roll-to-roll method, a paint in which an insulating substance (for example, an inorganic filler) is dispersed in a solvent as the material of the insulating layer 13 is applied onto the current collector 11 by a high-precision coating method such as a gravure roll method or an inkjet method, and then dried to evaporate the solvent, thereby obtaining the insulating layer 13. As a result, an insulating layer 13 with a uniform thickness and good positional accuracy is formed. Also, by using such a high-precision coating method, the accuracy of the area of the electrode active material layer 12 that is substantially effective as an electrode is improved.

[0141] When a resin is used as the material of the insulating layer 13, a solution in which the resin is dissolved or dispersed may be applied onto the current collector 11, or an ultraviolet curable resin or a thermosetting resin may be applied onto the current collector 11 and then cured. Also, a resin containing an inorganic filler may be applied. Note that the formation of the insulating layer 13 is not limited to a continuous process such as a roll-to-roll method, and a batch process in which the insulating layer 13 is formed for each single current collector 11 may be used.

[0142] Also, as the material of the insulating layer 13, for example, materials such as inorganic fillers having a larger linear expansion coefficient than the material of the electrode active material layer 12 are included. Also, the material of the insulating layer 13 may include a material having poor wettability with the slurry of the material of the electrode active material layer 12 described later, that is, a material that repels the slurry, such as a fluorine-containing resin. Also, the surface of the insulating layer 13 may be coated with a coating agent such as a fluorine-based coating agent in order to adjust the surface tension so as to repel the slurry.

[0143] As the solvent used for forming the insulating layer 13, general organic solvents or aqueous solvents that disperse or dissolve inorganic fillers and / or resins can be used.

[0144] (2) Power generation element lamination step Next, the power generation element lamination process will be described. In the power generation element lamination process, the power generation element portion 40 having voids 14 formed therein is formed, for example, by sequentially laminating an electrode active material layer 12, a solid electrolyte layer 30, and a counter electrode active material layer 22 on a current collector 11. For example, an electrode active material layer 12 is laminated on the current collector 11 on which an insulating layer 13 is laminated so as to cover the insulating layer 13, heat treatment is performed to form voids 14, and then the solid electrolyte layer 30 and the counter electrode active material layer 22 are sequentially laminated (steps S13, S14, S15, and S16 in FIG. 9). Further, if necessary, high-pressure pressing treatment is performed on the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 laminated in steps S13, S15, and S16 (step S17 in FIG. 9). Further, if necessary, heat treatment is performed on the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 laminated in steps S13, S15, and S16. As a result, a laminated electrode plate is obtained in which the power generation element portion 40 is laminated on the current collector 11 on which the insulating layer 13 is laminated, and voids 14 are formed that divide the electrode active material layer 12 into an electrode active material layer 12a and an electrode active material layer 12b.

[0145] The electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 constituting the power generation element portion 40 are each formed in order, for example, using a wet coating method. By using the wet coating method, the power generation element portion 40 can be easily laminated on the current collector 11. As the wet coating method, coating methods such as a die coating method, a doctor blade method, a roll coater method, a screen printing method, or an inkjet method are used, but are not limited to these methods.

[0146] When using the wet coating method, a coating process is performed in which the materials for forming each of the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 (the materials for the positive electrode active material layer, the solid electrolyte layer 30, and the negative electrode active material layer described above) and a solvent are appropriately mixed to obtain a slurry.

[0147] As the solvent used in the coating process, known solvents used when manufacturing known all-solid-state batteries (for example, lithium-ion all-solid-state batteries) can be used.

[0148] The slurry of each layer obtained in the coating process is laminated and coated on the current collector 11 on which the insulating layer 13 is formed in the order of the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22. First, in steps S13 and S14, the electrode active material layer 12 is laminated to form the void 14. For example, the slurry of the electrode active material layer 12 is coated, and after coating, for example, a heat treatment for removing the solvent and the binder material and a high-pressure pressing treatment for promoting the filling of the materials of each layer are performed. At this time, for example, the void 14 is formed by the surface tension of the insulating layer 13 and / or the expansion and contraction of the insulating layer 13 during the heat treatment. Further, when the insulating layer 13 has a shape having a long portion such as a lattice shape or a stripe shape, the void 14 is formed, for example, along the long direction of the insulating layer 13.

[0149] The process of forming the void 14 in steps S13 and S14 will be described in detail.

[0150] FIG. 11A is a diagram for explaining an example of a method of forming the gap 14. First, in step S13, as shown in FIG. 11A(a), a slurry of the material of the electrode active material layer 12 is applied so as to cover the insulating layer 13 on the current collector 11 on which the insulating layer 13 is laminated, thereby laminating the electrode active material layer 12. Then, in step S14, the current collector 11 on which the electrode active material layer 12 is laminated is heat-treated, so that the current collector 11, the electrode active material layer 12, and the insulating layer 13 expand. At this time, as the material of the insulating layer 13, a material having a larger coefficient of linear expansion than the material of the electrode active material layer 12 is used, so that the electrode active material layer 12 is less likely to expand than the insulating layer 13. Therefore, a force acts to separate between the electrode active material layer 12 on the insulating layer 13 and the electrode active material layer 12 on the current collector 11 at a position where the insulating layer 13 is not laminated. As a result, as shown in FIG. 11A(b), a gap 14 is formed that divides the electrode active material layer 12 into an electrode active material layer 12a and an electrode active material layer 12b. In this way, when the electrode active material layer 12 is formed using the wet coating method, if the insulating layer 13 contains an inorganic filler, by selecting an inorganic filler having a larger coefficient of linear expansion than the electrode active material layer 12, an insulating layer 13 having a larger coefficient of linear expansion than the electrode active material layer 12 can be formed, so that the gap 14 can be easily formed.

[0151] In the example of FIG. 11A, the gap 14 is formed at both ends of the upper surface of the insulating layer 13, but the position where the gap is formed is not limited to such an example. The position where the gap is formed can be adjusted, for example, by the difference in the coefficient of linear expansion between the insulating layer 13 and the electrode active material layer 12, the adhesion strength between the current collector 11 and the electrode active material layer 12, and the coefficient of linear expansion of the current collector 11.

[0152] Further, the voids can also be formed by using a material that repels the slurry (i.e., a material with poor wettability with the slurry) for the insulating layer 13. FIG. 11B is a diagram for explaining another example of a method for forming voids. First, in step S13, as shown in FIG. 11B(a), the electrode active material layer 12 is laminated by applying a slurry of the material of the electrode active material layer 12 so as to cover the insulating layer 13 on the current collector 11 on which the insulating layer 13 is laminated. At this time, as shown in FIG. 11B(b), since the insulating layer 13 contains a material that repels the slurry of the material of the electrode active material layer 12, the slurry in contact with the insulating layer 13 flows, and the insulating layer 13 is exposed. Thereby, for example, the void 14c in the battery 50c is formed. Thus, when forming the electrode active material layer 12 using the wet coating method, if the insulating layer contains a resin, it is possible to adjust the surface tension of the resin to form the insulating layer 13 having a surface tension that repels the slurry, so that the void 14c can be easily formed.

[0153] In the example of FIG. 11B, the void 14c is formed such that the upper surface and both side surfaces of the insulating layer 13 are exposed. However, the position where the voids are formed is not limited to such an example. The position where the voids are formed can be adjusted, for example, by the wettability of the slurry with respect to the insulating layer 13, the thickness of the slurry of the material of the electrode active material layer 12 that covers the insulating layer 13, and the like.

[0154] Further, the method for forming the voids is not limited to the methods described in FIGS. 11A and 11B, and may be a method of applying the material of the electrode active material layer 12 in a pattern such that the electrode active material layer 12 is divided by the voids.

[0155] Subsequently, lamination coating is performed in the order of the solid electrolyte layer 30 and the counter electrode active material layer 22. At this time, the lamination coating of the next layer may be performed after the lamination coating of the previously laminated layer is completed, or the lamination coating of the next layer may be started during the lamination coating of the previously laminated layer. That is, steps S15 and S16 may be performed simultaneously in parallel. The slurries of each layer are sequentially coated, and after the coating of all layers, for example, a heat treatment for removing the solvent and the binder material and a high-pressure pressing treatment for promoting the filling of the materials of each layer are performed. Note that the heat treatment and the high-pressure pressing treatment may be performed for each coating of each layer. That is, step S17 may also be performed between steps S15 and S16 respectively. The heat treatment and the high-pressure pressing treatment may be performed for each coating lamination of one layer in the coating lamination of the solid electrolyte layer 30 and the counter electrode active material layer 22, or may be performed collectively after the coating lamination of all two layers. In addition, for the high-pressure pressing treatment, for example, a roll press or a flat press is used. Note that at least one of the heat treatment and the high-pressure pressing treatment may not be performed.

[0156] By performing the lamination coating method in this way, it is possible to improve the bonding property at the interface of each layer of the current collector 11, the insulating layer 13, the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 and reduce the interface resistance. In addition, it is possible to improve the bonding property and reduce the grain boundary resistance in the powder materials used for the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22. That is, a good interface is formed between the layers of the power generation element unit 40 and between the powder materials inside each layer.

[0157] Note that the insulating layer lamination step and the power generation element lamination step may be performed in a continuous process such as a roll-to-roll method.

[0158] Further, in the power generation element lamination step, the solid electrolyte layer 30 and the counter electrode active material layer 22 were formed by being sequentially laminated on the current collector 11 on which the insulating layer 13 and the electrode active material layer 12 were laminated, but it is not limited thereto. For example, in the power generation element lamination step, at least one layer of the solid electrolyte layer 30 and the counter electrode active material layer 22 is formed by laminating on a sheet-like substrate, and the formed solid electrolyte layer 30 and counter electrode active material layer 22 are removed from the substrate and laminated on the current collector 11 on which the insulating layer 13 and the electrode active material layer 12 are laminated.

[0159] Figs. 12A, 12B, and 12C are schematic cross-sectional views showing examples of the laminated electrode plate according to the present embodiment. As shown in Fig. 12A, in the laminated electrode plate 41, a power generation element portion 40 in which the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 are laminated in this order is laminated on the current collector 11 on which the insulating layer 13 is laminated. Further, the electrode active material layer 12 is divided into an electrode active material layer 12a and an electrode active material layer 12b, and a gap 14 in contact with the insulating layer 13 is formed inside the power generation element portion 40. Also, the upper surface of the counter electrode active material layer 22 is exposed.

[0160] The structure of the laminated electrode plate 41 is not limited to this example. For example, as shown in Fig. 12B, the laminated electrode plate 41a is formed such that the side surface and the upper surface of the electrode active material layer 12 are covered with the solid electrolyte layer 30, and the side surface and the upper surface of the solid electrolyte layer 30 are covered with the counter electrode active material layer 22. Also, in the laminated electrode plate 41a, the electrode active material layer 12 is divided into an electrode active material layer 12a and an electrode active material layer 12b, and a gap 14 in contact with the insulating layer 13 is formed inside the power generation element portion 40. Thereby, since the electrode active material layer 12 is covered with the solid electrolyte layer 30, the occurrence of a short circuit due to the contact between the electrode active material layer 12 and the counter electrode active material layer 22 is suppressed in the power generation element lamination step.

[0161] Further, for example, as shown in FIG. 12C, the laminated electrode plate 41b is formed such that the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 have smaller areas in this order in plan view. Also, in plan view, the counter electrode active material layer 22 is located inside the solid electrolyte layer 30, and the solid electrolyte layer 30 is located inside the electrode active material layer 12. Further, in the laminated electrode plate 41b, the electrode active material layer 12 is divided into an electrode active material layer 12a and an electrode active material layer 12b, and a gap 14 in contact with the insulating layer 13 is formed inside the power generation element portion 40. Since the counter electrode active material layer 22 is designed to be located inside the solid electrolyte layer 30, even if the lamination position in plan view is shifted when laminating the counter electrode active material layer 22, the solid electrolyte layer 30 suppresses the occurrence of a short circuit due to contact between the electrode active material layer 12 and the counter electrode active material layer 22.

[0162] The laminated electrode plate in the present embodiment may have any of the structures of the laminated electrode plates 41, 41a, and 41b. The power generation element portion 40 is laminated on the current collector 11 on which the insulating layer 13 is laminated. As long as a gap is formed inside the power generation element portion 40, which is located between the current collector 11 and the solid electrolyte layer 30 and in contact with the insulating layer 13, a structure other than the laminated electrode plates 41, 41a, and 41b may be used.

[0163] (3) Cutting step and current collector lamination step Next, the cutting process and the current collector lamination process will be described. FIG. 13 is a diagram for explaining the cutting process in the method for manufacturing a battery according to the present embodiment. In the cutting process, the current collector 11 on which the power generation element portion 40 is laminated in the power generation element lamination process, that is, the laminated electrode plates 41, 41a, or 41b are collectively cut in the lamination direction at the position where the insulating layer 13 is divided (step S18 in FIG. 9). As shown in FIG. 13, the laminated electrode plate 41 is cut by a blade, a laser beam, or the like, for example, at the positions of the broken lines C1, C2, C3, and C4 where the insulating layer 13 is disposed. At the positions of the broken lines C1, C2, C3, and C4, the current collector 11, the insulating layer 13, the electrode active material layer 12b in the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 are laminated in this order, and these are collectively cut. As a result, it is not necessary to laminate each layer of the power generation element portion 40 in the shape after cutting, so that the battery 50 can be easily manufactured. For example, when the insulating layer 13 is laminated in a lattice shape or a stripe shape having a long portion as shown in FIGS. 10A, 10B, and 10C in plan view, the current collector 11 on which the power generation element portion 40 is laminated is collectively cut along the long direction of the lattice or stripe of the insulating layer 13. Thereby, the insulating layer 13 is located in the entire region of the end portion on the cut surface side of the manufactured battery 50, and a battery 50 having a gap 14 in contact with the insulating layer 13 is obtained.

[0164] Next, in the current collector lamination process, a current collector 21 is laminated as an additional current collector on the surface of the laminated electrode plate 41 on the side opposite to the current collector 11 side of the power generation element portion 40 after being cut in the cutting process (the surface of the plane perpendicular to the lamination direction of the power generation element portion 40 where the current collector 11 is not laminated) (step S19 in FIG. 9). Specifically, the current collector 21 is joined to the upper surface of the exposed counter electrode active material layer 22 of the cut laminated electrode plate 41 by press processing or the like. The press processing is performed at a pressure lower than, for example, the high-pressure press processing in step S17. Thereby, the battery 50 shown in FIGS. 1 and 2 is obtained.

[0165] Note that the cutting process and the current collector lamination process may be in reverse order. That is, after laminating the current collector 21 on the surface of the laminated electrode plate 41 opposite to the current collector 11 side of the power generation element portion 40 before being cut in the cutting process, the laminated electrode plate 41 on which the current collector 21 is laminated may be cut in the lamination direction at the position where the insulating layer 13 is divided. Further, in the current collector lamination process, as an additional current collector, a conductive substrate or housing may be laminated on the surface of the power generation element portion 40 opposite to the current collector 11 side instead of the current collector 21.

[0166] Thus, the method for manufacturing the battery 50 includes a cutting process of cutting the position where the current collector 11, the insulating layer 13, the electrode active material layer 12b in the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 are laminated. Thereby, on the end portion in the direction perpendicular to the lamination direction, the side surfaces of the current collector 11, the insulating layer 13, the electrode active material layer 12b, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 are exposed. Note that after cutting, in order to protect the exposed side surfaces, a sealing member or the like for covering the side surfaces may be disposed. That is, when covering the side surfaces with other members such as a sealing member, the side surfaces of all the layers may not be exposed.

[0167] Thus, by including the cutting process of cutting the position where the current collector 11, the insulating layer 13, the electrode active material layer 12b, the solid electrolyte layer 30, and the counter electrode active material layer 22 are laminated, the end portions in the direction perpendicular to the lamination direction of the current collector 11, the insulating layer 13, the electrode active material layer 12b, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21 are exposed.

[0168] (4) Effects, etc. As described above, the method for manufacturing the battery 50 according to the present embodiment includes an insulating layer lamination step, a power generation element lamination step, a cutting step, and a current collector lamination step. In the insulating layer lamination step, the insulating layer 13 is laminated on a part of at least one surface of the current collector 11. In the power generation element lamination step, the power generation element part 40 in which the electrode active material layer 12, the solid electrolyte layer 30, and the counter electrode active material layer 22 are laminated in this order, and the current collector 11 on which the insulating layer 13 is formed are laminated. Further, in the power generation element lamination step, a gap 14 is formed inside the power generation element part 40, which is located between the current collector 11 and the solid electrolyte layer 30 and is in contact with the insulating layer 13. In the cutting step, the current collector 11 on which the power generation element part 40 is laminated is cut in the lamination direction at a position where the insulating layer 13 is divided. In the current collector lamination step, the current collector 21 is laminated on the surface of the power generation element part 40 opposite to the current collector 11 side before or after being cut in the cutting step.

[0169] As a result, the current collector 11 on which the power generation element part 40 is laminated is collectively cut in the lamination direction at a position where the insulating layer 13 is divided. Therefore, since it is not necessary to laminate the layers of the power generation element part 40 in the shape after cutting, the battery 50 can be easily manufactured.

[0170] Further, since the current collector 11 on which the power generation element part 40 is laminated is cut in the lamination direction at a position where the insulating layer 13 is divided, a battery is manufactured in which the insulating layer 13 is laminated at the end of the current collector 11 in plan view. Furthermore, at the end of the current collector 11 in the plan view of the manufactured battery 50, the current collector 11, the insulating layer 13, and the electrode active material layer 12b are laminated in this order. Therefore, even if the current collector 11 peels off at the end of the current collector 11 where peeling is likely to occur, the insulating layer 13 is exposed, and further, since the electrode active material layer 12b in contact with the upper surface of the insulating layer 13 also does not function as a battery, damage or short circuit due to contact with other members is less likely to occur. Thus, a highly reliable battery can be manufactured.

[0171] Moreover, by simply adjusting the cutting position, the dimensions of the insulating layer 13 and the electrode active material layer 12b can be determined. Therefore, although the presence of the gap 14 formed in contact with the insulating layer 13 blocks the transfer of electrons between the electrode active material layer 12b and the current collector 11 and the electrode active material layer 12b does not function as an electrode, this region can be minimized by adjusting the dimensions of the insulating layer 13 and the electrode active material layer 12b. Thus, a battery 50 with a high volumetric energy density can be easily manufactured.

[0172] Further, when the electrode active material layer 12 is a positive electrode active material layer and the counter electrode active material layer 22 is a negative electrode active material layer, the gap 14 divides the end portion of the positive electrode active material layer (electrode active material layer 12), so that the positive electrode active material layer (electrode active material layer 12b) at the end portion does not function as an electrode because electrons from the current collector 11 cannot reach it. That is, the substantial area of the positive electrode active material layer in plan view is reduced. Therefore, the positive electrode active material layer has a smaller substantial area (the area functioning as an electrode) than the negative electrode active material layer and is located inside the negative electrode active material layer in plan view. As a result, the deposition of metal on the negative electrode active material layer as described above is suppressed. Thus, the reliability of the manufactured battery 50 is further improved.

[0173] Also, by cutting in the stacking direction, a battery can be obtained in which the current collector 11 (for example, the stacked electrode plates 41, 41a, or 41b) on which the power generation element portions 40 are stacked are cut all at once, and a gap 14 in contact with the insulating layer 13 is formed at the end portion of the power generation element portion 40. Therefore, since it is not necessary to individually stack the positive electrode active material layer and the negative electrode active material layer having a shape with an area difference for each single battery, the battery 50 can be easily and efficiently manufactured.

[0174] In the case where there is no insulating layer 13 and void 14, even if the current collector 11 with the power generation element portion 40 laminated thereon is cut all at once, since the electrode active material layer 12 that is not divided is also laminated on the end portion of the current collector 11, when the end portion of the current collector 11 peels off, the exposure of the electrode active material layer 12 that functions as a battery cannot be suppressed, and a battery in which there is no substantial difference in the area between the electrode active material layer 12 and the counter electrode active material layer 22 is manufactured. Therefore, even if the battery can be easily manufactured, the reliability of the battery decreases, making it difficult to adopt as a manufacturing method. On the other hand, in the manufacturing method according to the present embodiment, as described above, at the position where the insulating layer 13 is divided, the current collector 11 with the power generation element portion 40 laminated thereon is cut all at once. Therefore, by cutting the current collector 11 with the power generation element portion 40 laminated thereon all at once, in addition to being able to easily manufacture the battery, it is possible to reduce the area that functions as an electrode of the electrode active material layer 12 and adjust the areas of the insulating layer 13 and the electrode active material layer 12b. Further, by forming the void 14, the void 14 can relieve the stress caused by the expansion and contraction of the electrode active material layer 12, and can make it difficult to cause delamination between the electrode active material layer 12 and other components. In this way, by combining the current collector lamination step of laminating the insulating layer 13 on the current collector 11, the power generation element lamination step of laminating the power generation element portion 40 in which the void 14 in contact with the insulating layer 13 is formed inside, and the cutting step of cutting the current collector 11 with the power generation element portion 40 laminated thereon at the position where the insulating layer 13 is divided, it is possible to easily manufacture a battery with high reliability and high volumetric energy density.

[0175] (5) Other manufacturing methods The manufacturing method of the battery according to the present embodiment is not limited to the above example, and for example, it may be the manufacturing method shown below.

[0176] First, prepare a current collector 11 having the shape shown in FIGS. 1 and 2. Then, using a coating process or the like, laminate the insulating layer 13 on the current collector 11 in the shape shown in FIGS. 1 and 2. The electrode active material layer 12 is formed by coating on the entire surface of the current collector 11 on which the insulating layer 13 is laminated, and an electrode plate having the void 14 is obtained by the same method as the method described for the formation of the void 14 in steps S13 and S14 above.

[0177] Next, a current collector 21 having the shape shown in FIGS. 1 and 2 is prepared. Then, each layer of the counter electrode active material layer 22 and the solid electrolyte layer 30 is laminated on the entire surface of the current collector 21 in this order by laminating coating to obtain a counter electrode plate.

[0178] Next, the obtained electrode plate and counter electrode plate are laminated so that the electrode active material layer 12 of the electrode plate and the solid electrolyte layer 30 of the counter electrode plate are in contact with each other. The laminated body is pressed from both sides in the lamination direction using a flat press to obtain a battery 50.

[0179] (Embodiment 2) Hereinafter, Embodiment 2 will be described. In the following description of Embodiment 2, the differences from Embodiment 1 will be mainly described, and the description of the common points will be omitted or simplified.

[0180] FIG. 14 is a schematic cross-sectional view showing an example of a battery according to the present embodiment. As shown in FIG. 14, the battery 100 includes a plurality of batteries 50 according to Embodiment 1 and has a structure in which the plurality of batteries 50 are laminated. The plurality of batteries 50 are laminated such that one electrode layer 10 and the other counter electrode layer 20 of the batteries 50 adjacent to each other in the lamination direction face each other. That is, the battery 100 is a series-laminated type battery. Thereby, a high-voltage battery 100 can be realized using the battery 50 according to Embodiment 1.

[0181] The side surface of the battery 100 is a flat plane. In other words, the side surfaces of the plurality of batteries 50 are flush. Note that the plurality of batteries 50 may be laminated with a shift in a direction perpendicular to the lamination direction in order to connect leads or the like.

[0182] The battery 100 is manufactured, for example, by stacking a plurality of batteries 50 such that one electrode layer 10 and the other counter electrode layer 20 of the adjacent batteries 50 in the stacking direction face each other. Also, in the stacked electrode plate 41 (see FIG. 12A) before being cut, the current collector 21 is stacked on the side opposite to the current collector 11 of the power generation element portion 40, and after stacking a plurality of stacked electrode plates 41 on which the current collector 21 is stacked, the battery 100 may be manufactured by cutting in the stacking direction at the position where the insulating layer 13 is divided.

[0183] Note that when the batteries 50 are stacked, the two current collectors 11 and 21 are adjacent to each other. However, even a battery without one of the adjacent current collectors 11 and 21 may be used.

[0184] Also, although the battery 100 is a series-stacked type battery, it may be a parallel-stacked type battery having a structure in which the electrode layers 10 or the counter electrode layers 20 of the adjacent batteries 50 are stacked so as to face each other. In the parallel-stacked type battery, a high-capacity battery can be realized.

[0185] By stacking the single batteries 50 in this way, a high-capacity or high-voltage battery that can exhibit the same effects as the battery 50 can be realized.

[0186] (Other Embodiments) As described above, the battery and its manufacturing method according to the present disclosure have been described based on the embodiments. However, the present disclosure is not limited to these embodiments. As long as the gist of the present disclosure is not deviated from, various modifications conceived by those skilled in the art applied to the embodiments and other forms constructed by combining some components in the embodiments are also included in the scope of the present disclosure.

[0187] In the above embodiment, the battery 50 is composed of the current collector 11, the insulating layer 13, the electrode active material layer 12, the solid electrolyte layer 30, the counter electrode active material layer 22, and the current collector 21. However, the present disclosure is not limited thereto. For example, within the range where the battery characteristics are acceptable, a bonding layer or the like for reducing the electrical resistance and improving the bonding strength may be provided between the respective layers of the battery.

[0188] Further, in the above-described embodiment, the void 14 was in contact with the insulating layer 13 and the solid electrolyte layer 30, but it is not limited thereto. The void may be in contact with the insulating layer 13 and not in contact with the solid electrolyte layer 30.

[0189] In addition to the configuration of the battery 50 in the above-described embodiment, the battery 50 may have a second insulating layer located between the current collector 21 and the counter electrode active material layer 22 at the end of the counter electrode layer 20, and a second void located between the second insulating layer and the solid electrolyte layer 30 and in contact with the second insulating layer. In this case, the length of the second insulating layer from the outer periphery of the current collector 21 in plan view may be shorter than the length of the insulating layer 13 from the outer periphery of the current collector 11.

[0190] Further, in the above-described embodiment, the insulating layer 13 and the void 14 were located in the outer peripheral portion of the electrode layer 10 and were in a frame shape in plan view, but it is not limited thereto. For example, in the battery 50, there may be a region in the outer peripheral portion of the electrode layer 10 where the insulating layer 13 and / or the void 14 are not provided.

[0191] Further, for example, in the above-described embodiment, when the battery 50 is surrounded by a housing or a substrate or the like and a part of the housing or the substrate functions as a current collector, the current collector 21 on the counter electrode active material layer 22 side of the battery 50 may not be provided. In other words, the counter electrode layer 20 may be composed of the counter electrode active material layer 22.

[0192] Further, the above-described embodiment can be variously modified, replaced, added, omitted, etc. within the scope of the claims or the equivalent scope thereof.

Industrial Applicability

[0193] The battery according to the present disclosure can be used as a secondary battery such as an all-solid-state battery used in various electronic devices or automobiles, for example.

Explanation of Reference Numerals

[0194] 10, 10a, 10b, 10c, 10d Electrode layer 11, 21 Current collector 12, 12a, 12b, 12c, 12d, 12e, 12f, 12g, 12h, 12i, 12j, 12k, 12l Electrode active material layer 13 Insulating layer 13a Bonding surface 13b End portion 14, 14a, 14b, 14c, 14d Void 20 Counter electrode layer 22 Counter electrode active material layer 30 Solid electrolyte layer 40 Power generation element section 41, 41a, 41b Stacked electrode plate 50, 50a, 50b, 50c, 50d, 100 Battery

Claims

1. A battery, comprising: an electrode layer; a counter electrode layer disposed opposite to the electrode layer; a solid electrolyte layer positioned between the electrode layer and the counter electrode layer; wherein the electrode layer includes a current collector; an electrode active material layer located between the current collector and the solid electrolyte layer; and an insulating layer located between the current collector and the solid electrolyte layer at an end portion of the electrode layer and joined to the current collector; the electrode active material layer has a region that does not overlap with the insulating layer in plan view; the battery has a void located between the current collector and the solid electrolyte layer and in contact with the insulating layer; the side surfaces of the electrode layer, the counter electrode layer, and the solid electrolyte layer are flush; a battery.

2. A battery, comprising: an electrode layer; a counter electrode layer disposed opposite to the electrode layer; a solid electrolyte layer positioned between the electrode layer and the counter electrode layer; wherein the electrode layer includes a current collector; an electrode active material layer located between the current collector and the solid electrolyte layer; and an insulating layer located between the current collector and the solid electrolyte layer and between the current collector and the electrode active material layer at an end portion of the electrode layer and joined to the current collector; the electrode active material layer has a region that does not overlap with the insulating layer in plan view; the battery has a void located between the current collector and the solid electrolyte layer and in contact with the insulating layer; a battery.

3. The battery according to claim 1 or 2, wherein side surfaces of the insulating layer and the current collector are flush.

4. The battery according to claim 3, wherein the electrode layer is a positive electrode layer, and the counter electrode layer is a negative electrode layer.

5. The battery according to any one of claims 1 to 4, wherein the void further contacts the solid electrolyte layer.

6. The battery according to claim 5, wherein in plan view, the void overlaps with an inner end portion of a joint surface between the insulating layer and the current collector.

7. The battery according to any one of claims 1 to 6, wherein the void is located between the insulating layer and the solid electrolyte layer and between the insulating layer and the electrode active material layer, and the electrode active material layer and the insulating layer are not in contact.

8. The battery according to any one of claims 1 to 7, wherein the insulating layer contains a resin.

9. The battery according to any one of claims 1 to 8, wherein the insulating layer contains an inorganic filler.

10. The battery according to any one of claims 1 to 9, wherein the insulating layer has a larger coefficient of linear expansion than the electrode active material layer. the battery according to any one of claims 1 to 9.

11. The insulating layer is located in a region where the length from the outer periphery of the current collector in a plan view is 1 mm or less. The battery according to any one of claims 1 to 10.

12. The thickness of the insulating layer is 50% or more and 100% or less of the thickness of the electrode active material layer. The battery according to any one of claims 1 to 11.

13. The side surface of the battery is a cut surface. The battery according to any one of claims 1 to 12.

14. The insulating layer is provided at the outer peripheral portion of the electrode layer in a plan view and has a frame shape. The battery according to any one of claims 1 to 13.

15. The solid electrolyte layer contains a solid electrolyte having lithium ion conductivity. The battery according to any one of claims 1 to 14.

Images