Battery and method for manufacturing a battery

Abstract

This battery (1) is provided with: an electric power generation element (10) that comprises a plurality of battery cells (100), each of which comprises an electrode layer (110), a counter electrode layer (120) and a solid electrolyte layer (130) that is arranged between the electrode layer (110) and the counter electrode layer (120), wherein the plurality of battery cells (100) are stacked upon each other, while being electrically connected in parallel to each other; an electrode insulating layer (21) which covers the electrode layer (110) at a lateral surface (11) of the electric power generation element (10); and a counter electrode terminal (31) which covers the lateral surface (11) and the electrode insulating layer (21), while being electrically connected to the counter electrode layer (120).

Description

Technical Field

[0001] The present disclosure relates to a battery and a method for manufacturing a battery.

Background Art

[0002] Conventionally, a battery in which a plurality of serially connected battery cells are connected in parallel is known (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is a demand for further improvement in battery characteristics for conventional batteries.

[0005] Therefore, the present disclosure provides a high-performance battery and a method for manufacturing the same.

Means for Solving the Problems

[0006] A battery according to an aspect of the present disclosure includes a plurality of battery cells each including an electrode layer, a counter electrode layer, and a solid electrolyte layer positioned between the electrode layer and the counter electrode layer, the plurality of battery cells being electrically connected in parallel and stacked to form a power generation element, a first insulating member covering the electrode layer on a first side surface of the power generation element, and a first terminal electrode covering the first side surface and the first insulating member and being electrically connected to the counter electrode layer.

[0007] A method for manufacturing a battery according to one aspect of the present disclosure includes: a first step of preparing a plurality of battery cells, each containing an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer; a second step of forming a laminate by sequentially stacking the plurality of battery cells such that the order of the electrode layer, the counter electrode layer, and the solid electrolyte layer alternates; a third step of covering the electrode layer with an insulating member on one side of the laminate; and a fourth step of covering the one side and the insulating member with terminal electrodes electrically connected to the counter electrode layer. [Effects of the Invention]

[0008] This disclosure provides a high-performance battery and a method for manufacturing the same. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a cross-sectional view showing the cross-sectional configuration of a battery according to Embodiment 1. [Figure 2] Figure 2 is a top view of the power generation element of the battery according to Embodiment 1. [Figure 3A] Figure 3A is a cross-sectional view of an example of a battery cell included in the power generation element according to Embodiment 1. [Figure 3B] Figure 3B is a cross-sectional view of another example of a battery cell included in the power generation element according to Embodiment 1. [Figure 3C] Figure 3C is a cross-sectional view of another example of a battery cell included in the power generation element according to Embodiment 1. [Figure 4] Figure 4 is a cross-sectional view of the power generation element according to Embodiment 1. [Figure 5] Figure 5 is a side view showing the positional relationship between the first side surface of the power generation element according to Embodiment 1 and the electrode insulating layer provided on the first side surface. [Figure 6] Figure 6 is a side view showing the positional relationship between the second side surface of the power generation element according to Embodiment 1 and the counter electrode insulating layer provided on the second side surface. [Figure 7] Figure 7 is a cross-sectional view showing the cross-sectional configuration of the battery according to Embodiment 2. [Figure 8] FIG. 8 is a cross-sectional view showing a cross-sectional configuration of the battery according to Embodiment 3. [Figure 9] FIG. 9 is a cross-sectional view showing a cross-sectional configuration of the battery according to Embodiment 4. [Figure 10] FIG. 10 is a cross-sectional view showing a cross-sectional configuration of the battery according to Embodiment 5. [Figure 11] FIG. 11 is a cross-sectional view showing a cross-sectional configuration of the battery according to Modification 1. [Figure 12] FIG. 12 is a cross-sectional view showing a cross-sectional configuration of the battery according to Modification 2. [Figure 13] FIG. 13 is a cross-sectional view showing a cross-sectional configuration of the battery according to Modification 3. [Figure 14] FIG. 14 is a flowchart showing an example of a method for manufacturing the battery according to an embodiment or a modification. [Figure 15] FIG. 15 is a flowchart showing another example of a method for manufacturing the battery according to an embodiment or a modification.

MODE FOR CARRYING OUT THE INVENTION

[0010] (SUMMARY OF THE DISCLOSURE) A battery according to an aspect of the present disclosure includes a plurality of battery cells each including an electrode layer, a counter electrode layer, and a solid electrolyte layer positioned between the electrode layer and the counter electrode layer, the plurality of battery cells being electrically connected in parallel and stacked to form a power generation element, a first insulating member covering the electrode layer on a first side surface of the power generation element, and a first terminal electrode covering the first side surface and the first insulating member and being electrically connected to the counter electrode layer.

[0011] As a result, a high-performance battery can be realized. For example, since the first insulating member covers the electrode layer on the first side surface, the occurrence of a short circuit between the counter electrode layer and the electrode layer through the first terminal electrode can be suppressed. Further, for example, by electrically connecting all the battery cells in parallel, it is possible to suppress a specific battery cell from being overcharged or overdischarged due to the variation in the capacity of each battery cell. Thus, since the reliability of the battery can be enhanced, a high-performance battery can be realized.

[0012] Further, for example, the counter electrode layer includes a counter electrode current collector and a counter electrode active material layer positioned between the counter electrode current collector and the solid electrolyte layer. On the first side surface, the counter electrode current collector protrudes more than the counter electrode active material layer, and the first terminal electrode may contact the main surface of the counter electrode current collector.

[0013] As a result, at the protruding portion of the counter electrode current collector, the first terminal electrode contacts not only the end surface but also the main surface of the counter electrode current collector, so that the contact area between the first terminal electrode and the counter electrode current collector becomes larger. For this reason, the connection resistance between the first terminal electrode and the counter electrode current collector becomes smaller, and the high-current characteristics can be improved. For example, rapid charging of the battery becomes possible.

[0014] Further, for example, on the first side surface, the counter electrode active material layer may be recessed more than the electrode layer.

[0015] As a result, the contact area between the first terminal electrode and the counter electrode current collector can be further increased, so that the connection resistance between the first terminal electrode and the counter electrode current collector can be further reduced.

[0016] Further, for example, the end surface of the counter electrode current collector on the first side surface side and the end surface of the electrode layer on the first side surface side may coincide when viewed from a direction perpendicular to the main surface of the power generation element.

[0017] This allows for the easy formation of a power generation element by, for example, cutting multiple stacked battery cells simultaneously. By using simultaneous cutting, the area of ​​each layer—electrode layer, counter electrode layer, and solid electrolyte layer—is precisely determined without, for example, a gradual increase or decrease in film thickness at the beginning or end of the coating process. This reduces the variation in battery cell capacity, thereby improving the accuracy of the battery capacity.

[0018] Furthermore, for example, the thickness of the counter electrode current collector may be 20 μm or less.

[0019] This makes it possible to improve energy density, increase power density, and reduce material costs.

[0020] Furthermore, for example, the first insulating member may cover at least a portion of the solid electrolyte layer on its first side surface.

[0021] This allows the first insulating member to be formed so as to cover a portion of the solid electrolyte layer, thereby preventing the electrode layer from being exposed even if there are variations in the size of the first insulating member. Furthermore, since the solid electrolyte layer is generally made of powdered material, its edge surface has very fine irregularities. This improves the adhesion strength of the first insulating member and enhances insulation reliability. In this way, the reliability of the battery can be further enhanced.

[0022] Furthermore, for example, the first insulating member may, on its first side surface, cover from the electrode layer to a portion of the counter electrode layer along the stacking direction of the power generation element.

[0023] This effectively prevents the electrode layer from being exposed without being covered by the first insulating material, by covering even a portion of the counter electrode layer. Furthermore, since the counter electrode active material layer is generally made of powdered material, its edge surface has very fine irregularities. Therefore, the adhesion strength of the first insulating material is further improved, enhancing insulation reliability. This, in turn, further increases the reliability of the battery.

[0024] Furthermore, for example, a battery according to one aspect of the present disclosure further comprises a conductive member covering at least a portion of the counter electrode layer on the first side surface, and the first terminal electrode may further cover the conductive member.

[0025] This allows for the use of materials with different properties for the conductive component and the first terminal electrode. For example, the material used for the conductive component can be selected primarily based on its high conductivity and its suitability for alloying with the metal contained in the current collector. Similarly, the material used for the first terminal electrode can be selected primarily based on its flexibility, impact resistance, chemical stability, cost, and ease of application during installation. In this way, suitable materials can be selected for each component, improving battery performance and ease of manufacturing.

[0026] Furthermore, for example, the first insulating member may cover the electrode layer of each of the plurality of battery cells on its first side surface, and the first terminal electrode may be electrically connected to the counter electrode layer of each of the plurality of battery cells.

[0027] This allows the first terminal electrode to be used for parallel connection of multiple battery cells. Since the first terminal electrode can be brought into close contact with the first side surface and the first insulating member, the volume of the part involved in the parallel connection can be reduced. As a result, the energy density of the battery can be increased.

[0028] Furthermore, for example, the first insulating member may have a striped shape in a plan view of the first side surface.

[0029] This allows the end face of the electrode layer exposed in a stripe pattern on the first side surface to be covered by a stripe-shaped first insulating member.

[0030] Furthermore, for example, a battery according to one aspect of the present disclosure may further include, on the second side surface of the power generation element, a second insulating member covering the counter electrode layer, and a second terminal electrode covering the second side surface and the second insulating member, and electrically connected to the electrode layer.

[0031] This makes it possible to realize a higher-performance battery. Specifically, since the second insulating material covers the counter electrode layer on the second side surface, it is possible to suppress the occurrence of short circuits between the electrode layer and the counter electrode layer via the second terminal electrode. In this way, the reliability of the battery can be improved, and a high-performance battery can be realized.

[0032] Furthermore, for example, the electrode layer comprises an electrode current collector and an electrode active material layer located between the electrode current collector and the solid electrolyte layer, wherein, on the second side surface, the electrode current collector protrudes more than the electrode active material layer, and the second terminal electrode may be in contact with the main surface of the electrode current collector.

[0033] As a result, the second terminal electrode contacts not only the end face but also the main face of the electrode current collector at the protruding portion of the electrode current collector, thus increasing the contact area between the second terminal electrode and the electrode current collector. This reduces the connection resistance between the second terminal electrode and the electrode current collector, improving high-current characteristics. For example, it enables rapid charging of batteries.

[0034] Furthermore, for example, in the second side surface, the electrode active material layer may be recessed compared to the counter electrode layer.

[0035] This allows for an even larger contact area between the second terminal electrode and the electrode current collector, thereby further reducing the connection resistance between the second terminal electrode and the electrode current collector.

[0036] Furthermore, for example, the thickness of the electrode current collector may be 20 μm or less.

[0037] This makes it possible to improve energy density, increase power density, and reduce material costs.

[0038] Furthermore, for example, the second insulating member may cover the counter electrode layer of each of the plurality of battery cells on its second side surface, and the second terminal electrode may be electrically connected to the electrode layer of each of the plurality of battery cells.

[0039] This allows the use of a second terminal electrode for parallel connection of multiple battery cells. Since the second terminal electrode can be brought into close contact with the second side and second insulating member, the volume of the parts involved in the parallel connection can be reduced. Therefore, the energy density of the battery can be increased.

[0040] Furthermore, for example, the first insulating member may contain resin.

[0041] This improves the shock resistance of the battery. It also reduces the stress on the battery caused by temperature changes or expansion and contraction during charging and discharging.

[0042] Furthermore, for example, a battery according to one aspect of the present disclosure may further include a sealing member that exposes at least a portion of the first terminal electrode and seals the power generation element.

[0043] This protects the power generation elements from the outside air and water, thereby further enhancing the reliability of the battery.

[0044] Furthermore, a method for manufacturing a battery according to one aspect of the present disclosure includes: a first step of preparing a plurality of battery cells, each containing an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer; a second step of forming a laminate by sequentially stacking the plurality of battery cells such that the order of the electrode layer, the counter electrode layer, and the solid electrolyte layer alternates; a third step of covering the electrode layer with an insulating member on one side of the laminate; and a fourth step of covering the one side and the insulating member with terminal electrodes electrically connected to the counter electrode layer.

[0045] This makes it possible to manufacture the high-performance batteries mentioned above.

[0046] Furthermore, for example, a method for manufacturing a battery according to one aspect of the present disclosure may further include a fifth step of causing a portion of the counter electrode layer to protrude from another portion of the counter electrode layer on one side.

[0047] This increases the contact area between the terminal electrode and the counter electrode layer, thereby reducing the connection resistance between the terminal electrode and the counter electrode layer and improving the high-current characteristics of the battery.

[0048] Furthermore, for example, the fifth step may be performed after the third step and before the fourth step.

[0049] This allows the insulating member formed in the third step to function as a protective member in the fifth step.

[0050] Furthermore, for example, the fifth step may be performed by partial cutting, polishing, sandblasting, brushing, etching, or plasma irradiation of the one side surface.

[0051] As a result, for example, the insulating member functions as a protective member against sandblasting or plasma irradiation, so that the portion not covered by the insulating member is recessed, while the portion covered by the insulating member is made to protrude relatively. Alternatively, for example, the difference in strength between the current collector and the active material layer can be used to easily make the current collector protrude relative to the active material layer.

[0052] The embodiments will be described in detail below with reference to the drawings.

[0053] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, steps, and the order of steps shown in the following embodiments are examples only and are not intended to limit this disclosure. Furthermore, any components in the following embodiments that are not described in an independent claim will be described as optional components.

[0054] Furthermore, each figure is a schematic diagram and not necessarily a strictly accurate representation. Therefore, for example, the scale may not necessarily match in each figure. Also, in each figure, substantially identical components are given the same reference numerals, and redundant explanations are omitted or simplified.

[0055] Furthermore, in this specification, terms indicating relationships between elements such as parallel or orthogonal, terms indicating the shape of elements such as rectangles or cuboids, and numerical ranges do not represent only strict meanings, but also include substantially equivalent ranges, such as differences of a few percent.

[0056] Furthermore, in this specification and the drawings, the x, y, and z axes represent the three axes of a three-dimensional Cartesian coordinate system. The x and y axes correspond to the first side and the second side perpendicular to the first side of a rectangle, respectively, when the plan view shape of the power generation element of the battery is rectangular. The z axis corresponds to the stacking direction of the multiple battery cells included in the power generation element.

[0057] Furthermore, in this specification, the "stacking direction" coincides with the direction normal to the main surface of the current collector and the active material layer. Also, in this specification, "plan view" refers to the view from a direction perpendicular to the main surface of the power generation element, unless otherwise specified, such as when used alone. When it is written as "plan view of a certain surface," such as "plan view of the first side," it refers to the view of that "certain surface" from the front.

[0058] Furthermore, in this specification, the terms "upper" and "lower" do not refer to the upward (vertically upward) and downward (vertically downward) directions in absolute spatial perception, but rather to terms defined by the relative positional relationship based on the stacking order in a stacked configuration. In addition, the terms "upper" and "lower" apply not only when two components are spaced apart and another component exists between them, but also when two components are placed in close proximity and touching each other. In the following description, the negative side of the z-axis is referred to as "lower" or "bottom," and the positive side of the z-axis is referred to as "upper" or "top."

[0059] Furthermore, in this specification, ordinal numbers such as "first" and "second" do not mean the number or order of components unless otherwise specified, but are used to avoid confusion between similar components and to distinguish them.

[0060] (Embodiment 1) The configuration of the battery according to Embodiment 1 will be described below.

[0061] Figure 1 is a cross-sectional view showing the cross-sectional configuration of a battery 1 according to this embodiment. As shown in Figure 1, the battery 1 comprises a power generation element 10, an electrode insulating layer 21, a counter electrode insulating layer 22, a counter electrode terminal 31, and an electrode terminal 32. The battery 1 is, for example, an all-solid-state battery.

[0062] [1. Power generation elements] First, the specific configuration of the power generation element 10 will be explained using Figures 1 and 2. Figure 2 is a top view of the power generation element 10 of the battery 1 according to this embodiment. Figure 1 shows a cross-section along line II in Figure 2.

[0063] The plan view shape of the power generation element 10 is rectangular, as shown in Figure 2, for example. In other words, the shape of the power generation element 10 is a flattened rectangular parallelepiped. Here, "flattened" means that the thickness (i.e., the length in the z-axis direction) is shorter than the length of each side of the main face (i.e., the respective lengths in the x-axis and y-axis directions) or the maximum width. The plan view shape of the power generation element 10 may also be other polygons such as a square, hexagon, or octagon, or it may be circular or elliptical. Note that in cross-sectional views such as Figure 1, the thickness of each layer is exaggerated to make the layered structure of the power generation element 10 easier to understand.

[0064] The power generation element 10 includes four side surfaces 11, 12, 13, and 14 and two main surfaces 15 and 16, as shown in Figures 1 and 2. In this embodiment, the side surfaces 11, 12, 13, and 14, as well as the main surfaces 15 and 16, are all flat surfaces.

[0065] Side 11 is an example of a first side. Side 12 is an example of a second side. Sides 11 and 12 are opposite each other and parallel to each other. Sides 11 and 12 are sides that include the short side of the main surface 15.

[0066] Sides 13 and 14 are opposite each other and parallel to each other. Sides 13 and 14 each include the long side of the main surface 15.

[0067] The main surfaces 15 and 16 are opposite each other and parallel to each other. Main surface 15 is the uppermost surface of the power generation element 10. Main surface 16 is the lowermost surface of the power generation element 10.

[0068] As shown in Figure 1, the power generation element 10 has a plurality of battery cells 100. A battery cell 100 is the smallest battery configuration and is also called a unit cell. The plurality of battery cells 100 are electrically connected in parallel and stacked. In this embodiment, all of the battery cells 100 of the power generation element 10 are electrically connected in parallel. In the example shown in Figure 1, the power generation element 10 has 8 battery cells 100, but is not limited to this. For example, the number of battery cells 100 of the power generation element 10 may be an even number such as 2 or 4, or an odd number such as 3 or 5.

[0069] Each of the multiple battery cells 100 includes an electrode layer 110, a counter electrode layer 120, and a solid electrolyte layer 130. The electrode layer 110 has an electrode current collector 111 and an electrode active material layer 112. The counter electrode layer 120 has a counter electrode current collector 121 and a counter electrode active material layer 122. In each of the multiple battery cells 100, the electrode current collector 111, the electrode active material layer 112, the solid electrolyte layer 130, the counter electrode active material layer 122, and the counter electrode current collector 121 are stacked in this order along the z-axis.

[0070] The electrode layer 110 is one of the positive and negative electrode layers of the battery cell 100. The counter electrode layer 120 is the other of the positive and negative electrode layers of the battery cell 100. In the following explanation, we will describe the case where the electrode layer 110 is the negative electrode layer and the counter electrode layer 120 is the positive electrode layer as an example.

[0071] The configurations of the multiple battery cells 100 are substantially identical to each other. In two adjacent battery cells 100, the order of the layers constituting the battery cell 100 is reversed. In other words, the multiple battery cells 100 are stacked along the z-axis, with the order of the layers constituting the battery cell 100 alternating. In this embodiment, since the number of battery cells 100 is even, the bottom and top layers of the power generation element 10 become current collectors of the same polarity.

[0072] In the following section, Figure 3A will be used to describe each layer of the battery cell 100. Figure 3A is a cross-sectional view of the battery cell 100 included in the power generation element 10 according to this embodiment.

[0073] The electrode current collector 111 and the counter electrode current collector 121 are each conductive foil-shaped, plate-shaped, or mesh-shaped members. The electrode current collector 111 and the counter electrode current collector 121 may each be, for example, conductive thin films. As materials for constituting the electrode current collector 111 and the counter electrode current collector 121, metals such as stainless steel (SUS), aluminum (Al), copper (Cu), and nickel (Ni) can be used. The electrode current collector 111 and the counter electrode current collector 121 may be formed using different materials.

[0074] The thickness of the electrode current collector 111 and the counter electrode current collector 121 is, for example, 5 μm to 100 μm, but is not limited to this. The thickness of the electrode current collector 111 and the counter electrode current collector 121 may be 20 μm or less. By reducing the thickness of the current collector to 20 μm or less, improvements in energy density, power density, and material costs can be achieved. In this embodiment, since a single battery cell 100 is connected in parallel and stacked, the thickness of the power generation element 10 can be kept small even if the number of parallel connections is increased, contributing to an improvement in energy density. As the number of parallel connections increases, the number of current collectors also increases, so reducing the thickness of the current collectors is useful in suppressing the increase in the thickness of the power generation element 10.

[0075] The electrode active material layer 112 is in contact with the main surface of the electrode current collector 111. The electrode current collector 111 may also include a current collector layer containing a conductive material in the portion that is in contact with the electrode active material layer 112. The counter electrode current collector 121 is in contact with the counter electrode active material layer 122. The counter electrode current collector 121 may also include a current collector layer containing a conductive material in the portion that is in contact with the counter electrode active material layer 122.

[0076] The electrode active material layer 112 is located on the main surface of the electrode current collector 111, on the side facing the counter electrode layer 120. The electrode active material layer 112 includes, for example, a negative electrode active material as the electrode material. The electrode active material layer 112 is located opposite the counter electrode active material layer 122.

[0077] As the negative electrode active material contained in the electrode active material layer 112, for example, negative electrode active materials such as graphite and metallic lithium can be used. As the material for the negative electrode active material, various materials that can release and insert ions such as lithium (Li) or magnesium (Mg) can be used.

[0078] Furthermore, as the material containing the electrode active material layer 112, a solid electrolyte such as an inorganic solid electrolyte may be used. As an inorganic solid electrolyte, for example, a sulfide solid electrolyte or an oxide solid electrolyte may be used. As a sulfide solid electrolyte, for example, a mixture of lithium sulfide (Li2S) and phosphorus pentasulfide (P2S5) may be used. In addition, as the material containing the electrode active material layer 112, a conductive material such as acetylene black, or a binding binder such as polyvinylidene fluoride may be used.

[0079] The electrode active material layer 112 is produced by applying a paste-like coating, which is made by kneading the materials containing the electrode active material layer 112 together with a solvent, onto the main surface of the electrode current collector 111 and drying it. In order to increase the density of the electrode active material layer 112, the electrode layer 110 (also called an electrode plate), which includes the electrode active material layer 112 and the electrode current collector 111, may be pressed after drying. The thickness of the electrode active material layer 112 is, for example, 5 μm to 300 μm, but is not limited to this.

[0080] The counter electrode active material layer 122 is located on the main surface of the counter electrode current collector 121 on the electrode layer 110 side. The counter electrode active material layer 122 is a layer containing a positive electrode material, such as an active material. The positive electrode material is the material that constitutes the counter electrode of the negative electrode material. The counter electrode active material layer 122 contains, for example, a positive electrode active material.

[0081] As the positive electrode active material contained in the counter electrode active material layer 122, for example, positive electrode active materials such as lithium cobalt oxide composite oxide (LCO), lithium nickel oxide composite oxide (LNO), lithium manganese oxide composite oxide (LMO), lithium-manganese-nickel oxide composite oxide (LMNO), lithium-manganese-cobalt oxide composite oxide (LMCO), lithium-nickel-cobalt oxide composite oxide (LNCO), and lithium-nickel-manganese-cobalt oxide composite oxide (LNMCO) can be used. As the material for the positive electrode active material, various materials that can release and insert ions such as Li or Mg can be used.

[0082] Furthermore, as the material containing the counter electrode active material layer 122, a solid electrolyte such as an inorganic solid electrolyte may be used. As the inorganic solid electrolyte, sulfide solid electrolytes or oxide solid electrolytes may be used. As the sulfide solid electrolyte, for example, a mixture of Li2S and P2S5 may be used. The surface of the positive electrode active material may be coated with a solid electrolyte. Furthermore, as the material containing the counter electrode active material layer 122, a conductive material such as acetylene black, or a binding binder such as polyvinylidene fluoride may be used.

[0083] The counter electrode active material layer 122 is manufactured by applying a paste-like coating, in which the materials containing the counter electrode active material layer 122 are kneaded together with a solvent, onto the main surface of the counter electrode current collector 121 and drying it. In order to increase the density of the counter electrode active material layer 122, the counter electrode layer 120 (also called the counter electrode plate), which includes the counter electrode active material layer 122 and the counter electrode current collector 121, may be pressed after drying. The thickness of the counter electrode active material layer 122 is, for example, 5 μm to 300 μm, but is not limited to this.

[0084] The solid electrolyte layer 130 is placed between the electrode active material layer 112 and the counter electrode active material layer 122. The solid electrolyte layer 130 is in contact with both the electrode active material layer 112 and the counter electrode active material layer 122. The solid electrolyte layer 130 is a layer containing an electrolyte material. As the electrolyte material, generally known electrolytes for batteries can be used. The thickness of the solid electrolyte layer 130 may be 5 μm or more and 300 μm or less, or 5 μm or more and 100 μm or less.

[0085] The solid electrolyte layer 130 contains a solid electrolyte. As the solid electrolyte, for example, an inorganic solid electrolyte may be used. As an inorganic solid electrolyte, sulfide solid electrolytes or oxide solid electrolytes may be used. As a sulfide solid electrolyte, for example, a mixture of Li2S and P2S5 may be used. In addition to the electrolyte material, the solid electrolyte layer 130 may also contain a binding binder, such as polyvinylidene fluoride.

[0086] In this embodiment, the electrode active material layer 112, the counter electrode active material layer 122, and the solid electrolyte layer 130 are maintained in a parallel plate shape. This suppresses the occurrence of cracks or collapse due to bending. Alternatively, the electrode active material layer 112, the counter electrode active material layer 122, and the solid electrolyte layer 130 may be smoothly curved together.

[0087] Furthermore, in this embodiment, the end face of the counter electrode current collector 121 on the side surface 11 and the end face of the electrode layer 110 on the side surface 11 coincide when viewed from the z-axis direction. Specifically, the end face of the counter electrode current collector 121 on the side surface 11 and the end face of the electrode current collector 111 on the side surface 11 coincide when viewed from the z-axis direction. The same applies to the end faces of the respective side surfaces 12 of the counter electrode current collector 121 and the electrode current collector 111.

[0088] More specifically, in the battery cell 100, the electrode current collector 111, electrode active material layer 112, solid electrolyte layer 130, counter electrode active material layer 122, and counter electrode current collector 121 are all the same in shape and size, and their contours match. In other words, the shape of the battery cell 100 is a flat, rectangular parallelepiped.

[0089] As shown in Figure 1, in this embodiment, two adjacent battery cells 100 share a current collector. For example, the bottommost battery cell 100 and the battery cell 100 above it share an electrode current collector 111.

[0090] Specifically, as shown in Figure 1, in multiple battery cells 100, two adjacent electrode layers 110 share each other's electrode current collectors 111. Electrode active material layers 112 are provided on both sides of the main surface of the shared electrode current collector 111. Similarly, two adjacent counter electrode layers 120 share each other's counter electrode current collectors 121. Counter electrode active material layers 122 are provided on both sides of the main surface of the shared counter electrode current collector 121.

[0091] Such a battery 1 is formed by stacking not only the battery cell 100 shown in Figure 3A, but also battery cells 100B and 100C shown in Figures 3B and 3C. Here, the battery cell 100 shown in Figure 3A will be referred to as battery cell 100A.

[0092] The battery cell 100B shown in Figure 3B has the same configuration as the battery cell 100A shown in Figure 3A, but without the electrode current collector 111. In other words, the electrode layer 110B of the battery cell 100B consists only of the electrode active material layer 112.

[0093] The battery cell 100C shown in Figure 3C has the same configuration as the battery cell 100A shown in Figure 3A, but without the counter electrode current collector 121. In other words, the counter electrode layer 120C of the battery cell 100C consists only of the counter electrode active material layer 122.

[0094] Figure 4 is a cross-sectional view showing the power generation element 10 according to this embodiment. Figure 4 is a view showing only the power generation element 10 from Figure 1. As shown in Figure 4, a battery cell 100A is placed in the bottom layer, and battery cells 100B and 100C are stacked alternately upwards. At this time, the battery cells 100B are stacked in the opposite orientation to that shown in Figure 3B. This forms the power generation element 10.

[0095] The method for forming the power generation element 10 is not limited to this. For example, a battery cell 100A may be placed on the top layer. Alternatively, a battery cell 100A may be placed at a position different from both the top and bottom layers. Multiple battery cells 100A may also be used. Furthermore, by applying double-sided coating to a single current collector, two units of battery cells 100 sharing a current collector may be formed, and these formed units may be stacked.

[0096] As described above, in the power generation element 10 according to this embodiment, all battery cells 100 are connected in parallel, and no battery cells are connected in series. Therefore, when charging and discharging the battery 1, it is less likely that unevenness in the charge and discharge state will occur due to variations in the capacity of the battery cells 100. As a result, the risk of some of the multiple battery cells 100 becoming overcharged or over-discharged can be greatly reduced, and the reliability of the battery 1 can be improved.

[0097] [2. Insulating layer] Next, the electrode insulating layer 21 and the counter electrode insulating layer 22 will be described.

[0098] The electrode insulating layer 21 is an example of a first insulating member, and as shown in Figure 1, it covers the electrode layer 110 on the side surface 11. Specifically, the electrode insulating layer 21 completely covers the electrode current collector 111 and the electrode active material layer 112 on the side surface 11.

[0099] Figure 5 is a side view showing the positional relationship between the side surface 11 of the power generation element 10 according to this embodiment and the electrode insulating layer 21 provided on the side surface 11. In Figure 5, the end faces of each layer visible on the side surface 11 are shaded in the same way as the shading shown for each layer in the cross-section of Figure 1. The same applies to Figure 6, which will be described later.

[0100] Figure 5(a) is a side view of the power generation element 10, and a plan view of the side 11 as seen from the front. Figure 5(b) shows the side 11 of Figure 5(a) and the electrode insulating layer 21 provided on the side 11. In other words, Figure 5(b) is a side view of the battery 1 in Figure 1 as seen from the negative side of the x-axis, with the counter electrode terminal 31 visible through it.

[0101] As shown in Figure 5(b), the electrode insulating layer 21 covers each electrode layer 110 of the multiple battery cells 100 on the side surface 11. The electrode insulating layer 21 does not cover at least a portion of each counter electrode layer 120 of the multiple battery cells 100. Therefore, the electrode insulating layer 21 has a striped shape in a plan view of the side surface 11.

[0102] In this configuration, the electrode insulating layer 21 continuously covers the electrode layers 110 of two adjacent battery cells 100. Specifically, the electrode insulating layer 21 continuously covers at least a portion of the solid electrolyte layer 130 of one of the two adjacent battery cells 100, and at least a portion of the solid electrolyte layer 130 of the other of the two adjacent battery cells 100.

[0103] Thus, the electrode insulating layer 21 covers at least a portion of the solid electrolyte layer 130 on the side surface 11. Specifically, when the side surface 11 is viewed from above, the contour of the electrode insulating layer 21 overlaps with the solid electrolyte layer 130. This reduces the risk of exposing the electrode layer 110 even if the width (length in the z-axis direction) of the electrode insulating layer 21 fluctuates due to manufacturing variations. Therefore, it is possible to suppress short circuits between the electrode layer 110 and the counter electrode layer 120 via the counter electrode terminal 31 formed to cover the electrode insulating layer 21. In addition, the end face of the solid electrolyte layer 130, which is made of powdered material, has very fine irregularities. Therefore, the electrode insulating layer 21 penetrates these irregularities, improving the adhesion strength of the electrode insulating layer 21 and improving insulation reliability.

[0104] In this embodiment, the electrode insulating layer 21 may cover the entire solid electrolyte layer 130 on its side surface 11. Specifically, the contour of the electrode insulating layer 21 may overlap with the boundary between the solid electrolyte layer 130 and the counter electrode active material layer 122. It is not essential that the electrode insulating layer 21 covers only a portion of the solid electrolyte layer 130. For example, the contour of the electrode insulating layer 21 may overlap with the boundary between the solid electrolyte layer 130 and the electrode active material layer 112.

[0105] In Figure 5(b), the electrode insulating layer 21 is provided separately for each electrode layer 110, but this is not limited to this. For example, the electrode insulating layer 21 may be provided not only in the stripe-shaped portion but also along the z-axis direction at the end of the side surface 11 in the y-axis direction. In other words, the shape of the electrode insulating layer 21 may be ladder-shaped in a plan view of the side surface 11. Thus, the electrode insulating layer 21 may cover a part of the counter electrode current collector 121.

[0106] The counter electrode insulating layer 22 is an example of a second insulating member, and as shown in Figure 1, it covers the counter electrode layer 120 on the side surface 12. Specifically, the counter electrode insulating layer 22 completely covers the counter electrode current collector 121 and the counter electrode active material layer 122 on the side surface 12.

[0107] Figure 6 is a side view showing the positional relationship between the side surface 12 of the power generation element 10 according to this embodiment and the counter electrode insulating layer 22 provided on the side surface 12. Figure 6(a) is a side view of the power generation element 10, and is a plan view of the side surface 12 as seen from the front. Figure 6(b) shows the side surface 12 of Figure 6(a) and the counter electrode insulating layer 22 provided on the side surface 12. In other words, Figure 6(b) is a side view of the battery 1 in Figure 1 as seen from the positive side of the x-axis, with the electrode terminal 32 visible through it.

[0108] As shown in Figure 6(b), the counter electrode insulating layer 22 covers each of the counter electrode layers 120 of the multiple battery cells 100 on the side surface 12. The counter electrode insulating layer 22 does not cover at least a portion of each of the electrode layers 110 of the multiple battery cells 100. Therefore, the counter electrode insulating layer 22 has a striped shape in a plan view of the side surface 12.

[0109] In this configuration, the counter electrode insulating layer 22 continuously covers the counter electrode layers 120 of two adjacent battery cells 100. Specifically, the counter electrode insulating layer 22 continuously covers at least a portion of the solid electrolyte layer 130 of one of the two adjacent battery cells 100, and at least a portion of the solid electrolyte layer 130 of the other of the two adjacent battery cells 100.

[0110] Thus, the counter electrode insulating layer 22 covers at least a portion of the solid electrolyte layer 130 on the side surface 12. Specifically, when the side surface 12 is viewed from above, the contour of the counter electrode insulating layer 22 overlaps with the solid electrolyte layer 130. This reduces the risk of exposing the counter electrode layer 120 even if the width (length in the z-axis direction) of the counter electrode insulating layer 22 fluctuates due to manufacturing variations. Therefore, it is possible to suppress short circuits between the counter electrode layer 120 and the electrode layer 110 via the electrode terminal 32 formed to cover the counter electrode insulating layer 22. In addition, the adhesion strength of the counter electrode insulating layer 22 is improved as the counter electrode insulating layer 22 fits into the irregularities of the end face of the solid electrolyte layer 130, thereby improving insulation reliability.

[0111] In this embodiment, the counter electrode insulating layer 22 may cover the entire solid electrolyte layer 130 on its side surface 12. Specifically, the contour of the counter electrode insulating layer 22 may overlap the boundary between the solid electrolyte layer 130 and the electrode active material layer 112. It is not essential that the counter electrode insulating layer 22 covers only a portion of the solid electrolyte layer 130. For example, the contour of the counter electrode insulating layer 22 may overlap the boundary between the solid electrolyte layer 130 and the counter electrode active material layer 122.

[0112] In Figure 6(b), the counter electrode insulating layer 22 is provided separately for each counter electrode layer 120, but this is not limited to this. For example, in addition to the stripe-shaped portion, the counter electrode insulating layer 22 may be provided along the z-axis direction at the end of the side surface 12 in the y-axis direction. In other words, the shape of the counter electrode insulating layer 22 may be ladder-shaped in a plan view of the side surface 12. Thus, the counter electrode insulating layer 22 may cover a part of the electrode current collector 111.

[0113] Furthermore, in the power generation element 10 according to this embodiment, the uppermost and lowermost layers are counter electrode current collectors 121, respectively. As shown in Figures 1 and 6(b), near the upper and lower ends of the side surface 12, the counter electrode insulating layer 22 covers a portion of the main surface of the counter electrode current collector 121 located in the uppermost and lowermost layers, respectively. As a result, the counter electrode insulating layer 22 is resistant to external forces from the z-axis direction, and detachment is suppressed. In addition, even if the electrode terminal 32 wraps around to the main surface 15 or 16 of the power generation element 10, it can contact the counter electrode current collector 121, preventing a short circuit. In this way, the reliability of the battery 1 can be improved.

[0114] The electrode insulating layer 21 and the counter electrode insulating layer 22 are each formed using an electrically insulating material. For example, the electrode insulating layer 21 and the counter electrode insulating layer 22 each contain a resin. The resin is, for example, an epoxy resin, but is not limited to this. Inorganic materials may also be used as the insulating material. The usable insulating material is selected based on various properties such as flexibility, gas barrier properties, impact resistance, and heat resistance. The electrode insulating layer 21 and the counter electrode insulating layer 22 are formed using the same material, but they may also be formed using different materials.

[0115] [3. Terminals] Next, the counter electrode terminal 31 and the electrode terminal 32 will be described.

[0116] The counter electrode terminal 31 is an example of a first terminal electrode, and as shown in Figure 1, it covers the side surface 11 and the electrode insulating layer 21, and is electrically connected to the counter electrode layer 120. Specifically, the counter electrode terminal 31 covers the electrode insulating layer 21 and the portion of the side surface 11 that is not covered by the electrode insulating layer 21.

[0117] As shown in Figure 5(b), the end faces of the counter electrode current collector 121 and the counter electrode active material layer 122 are exposed in the portion of the side surface 11 that is not covered by the electrode insulating layer 21. Therefore, the counter electrode terminal 31 contacts the end faces of the counter electrode current collector 121 and the counter electrode active material layer 122, and is electrically connected to the counter electrode layer 120. Since the counter electrode active material layer 122 is made of a powdered material, it has very fine irregularities, similar to the solid electrolyte layer 130. The contact strength of the counter electrode terminal 31 is improved as it fits into the irregularities of the end face of the counter electrode active material layer 122, thereby improving the reliability of the electrical connection.

[0118] The counter electrode terminal 31 is electrically connected to the counter electrode layer 120 of each of the multiple battery cells 100. In other words, the counter electrode terminal 31 plays a part in electrically connecting each battery cell 100 in parallel. As shown in Figure 1, the counter electrode terminal 31 covers almost the entire side surface 11. In this embodiment, since the counter electrode layer 120 is the positive electrode, the counter electrode terminal 31 functions as the positive electrode extraction electrode of the battery 1.

[0119] In the power generation element 10 according to this embodiment, the uppermost and lowermost layers are counter electrode current collectors 121, respectively. As shown in Figure 1, near the upper and lower ends of the side surface 11, the counter electrode terminals 31 cover a portion of the main surface of the counter electrode current collectors 121 located in the uppermost and lowermost layers, respectively. As a result, the counter electrode terminals 31 are resistant to external forces from the z-axis direction, and detachment is suppressed. In addition, since the contact area between the counter electrode terminals 31 and the counter electrode current collectors 121 is increased, the connection resistance between the counter electrode terminals 31 and the counter electrode current collectors 121 is reduced, and the high-current characteristics can be improved. For example, rapid charging of the battery 1 becomes possible.

[0120] The electrode terminal 32 is an example of a second terminal electrode, and as shown in Figure 1, it covers the side surface 12 and the counter electrode insulating layer 22, and is electrically connected to the electrode layer 110. Specifically, the electrode terminal 32 covers the counter electrode insulating layer 22 and the portion of the side surface 12 that is not covered by the counter electrode insulating layer 22.

[0121] As shown in Figure 6(b), the end faces of the electrode current collector 111 and the electrode active material layer 112 are exposed in the portion of the side surface 12 that is not covered by the counter electrode insulating layer 22. Therefore, the electrode terminal 32 contacts the end faces of the electrode current collector 111 and the electrode active material layer 112, and is electrically connected to the electrode layer 110. Since the electrode active material layer 112 is made of a powdery material, it has very fine irregularities, similar to the solid electrolyte layer 130. The electrode terminal 32 fits into the irregularities of the end face of the electrode active material layer 112, improving the adhesion strength of the electrode terminal 32 and improving the reliability of the electrical connection.

[0122] The electrode terminal 32 is electrically connected to the electrode layer 110 of each of the multiple battery cells 100. In other words, the electrode terminal 32 plays a part in electrically connecting each battery cell 100 in parallel. As shown in Figure 1, the electrode terminal 32 covers almost the entire side surface 12. In this embodiment, since the electrode layer 110 is the negative electrode, the electrode terminal 32 functions as the negative electrode extraction electrode of the battery 1.

[0123] The counter electrode terminal 31 and the electrode terminal 32 are formed using a conductive resin material or the like. Alternatively, the counter electrode terminal 31 and the electrode terminal 32 may be formed using a metallic material such as solder. The usable conductive material is selected based on various properties such as flexibility, gas barrier properties, impact resistance, heat resistance, and solder wettability. The counter electrode terminal 31 and the electrode terminal 32 are formed using the same material, but they may also be formed using different materials.

[0124] As described above, the counter electrode terminal 31 and the electrode terminal 32 not only function as the positive electrode extraction electrode or the negative electrode extraction electrode of the battery 1, respectively, but also serve the function of parallel connection of multiple battery cells 100. As shown in Figure 1, the counter electrode terminal 31 and the electrode terminal 32 are formed to closely cover the sides 11 and 12 of the power generation element 10, respectively, so that their volumes can be reduced. In other words, the volume of the terminal electrodes is smaller than that of conventionally used tab electrodes for current collection, so that the energy density per unit volume of the battery 1 can be improved.

[0125] (Embodiment 2) Next, Embodiment 2 will be described.

[0126] The battery according to Embodiment 2 differs from the battery according to Embodiment 1 in that a different conductive member is connected to the end face of the current collector than the extraction terminal. Below, we will mainly explain the differences from Embodiment 1, and the explanation of the common points will be omitted or simplified.

[0127] Figure 7 is a cross-sectional view showing the cross-sectional configuration of the battery 201 according to this embodiment. As shown in Figure 7, the battery 201 further comprises a plurality of counter electrode conductive members 231 and a plurality of electrode conductive members 232, compared to the battery 1 shown in Figure 1.

[0128] The counter electrode conductive member 231 is a conductive member that covers at least a portion of the counter electrode layer 120 on the side surface 11. Specifically, the counter electrode conductive member 231 covers the end face of the counter electrode current collector 121 and a portion of the end face of the counter electrode active material layer 122. For example, the counter electrode conductive member 231 is provided for each counter electrode current collector 121 and covers the entire end face of the counter electrode current collector 121. In a plan view of the side surface 11, the counter electrode conductive member 231 and the electrode insulating layer 21 are arranged alternately one by one along the z-axis.

[0129] Each of the multiple counter electrode conductive members 231 is covered by the counter electrode terminal 31 and electrically connected. In other words, each counter electrode layer 120 of the multiple battery cells 100 is electrically connected to the counter electrode terminal 31 via each counter electrode conductive member 231 and electrically connected in parallel via the counter electrode terminal 31.

[0130] The counter electrode conductive member 231 has different properties from the counter electrode terminal 31. For example, the counter electrode conductive member 231 and the counter electrode terminal 31 are formed using different materials. Specifically, the counter electrode conductive member 231 is formed using a material selected primarily for its high conductivity and alloying with the counter electrode current collector 121. The counter electrode terminal 31 is formed using a material selected primarily for its flexibility, impact resistance, chemical stability, cost, and ease of spreading during installation.

[0131] The electrode conductive member 232 is a conductive member that covers at least a portion of the electrode layer 110 on the side surface 12. Specifically, the electrode conductive member 232 covers the end face of the electrode current collector 111 and a portion of the end face of the electrode active material layer 112. For example, the electrode conductive member 232 is provided for each electrode current collector 111 and covers the entire end face of the electrode current collector 111. In a plan view of the side surface 12, the electrode conductive member 232 has a stripe shape. On the side surface 12, the electrode conductive member 232 and the counter electrode insulating layer 22 are arranged alternately one by one along the z-axis direction.

[0132] Each of the multiple electrode conductive members 232 is covered by the electrode terminals 32 and electrically connected. In other words, each electrode layer 110 of the multiple battery cells 100 is electrically connected to the electrode terminals 32 via each electrode conductive member 232, and is electrically connected in parallel via the electrode terminals 32.

[0133] The electrode conductive member 232 has different properties from the electrode terminal 32. For example, the electrode conductive member 232 and the electrode terminal 32 are formed using different materials. Specifically, the considerations for the materials used for the electrode conductive member 232 and the electrode terminal 32 are the same as those for the counter electrode conductive member 231 and the counter electrode terminal 31, respectively.

[0134] As described above, an appropriate material can be used for the extraction terminals of the battery 201, thereby improving the battery's performance and enhancing the ease of manufacturing the battery.

[0135] In Figure 7, an example is shown in which all counter electrode current collectors 121 are connected to the counter electrode conductive member 231. However, there may be counter electrode current collectors 121 to which the counter electrode conductive member 231 is not connected. The same applies to the electrode current collector 111. Furthermore, one of the counter electrode conductive member 231 and the electrode conductive member 232 may be omitted.

[0136] (Embodiment 3) Next, Embodiment 3 will be described.

[0137] The battery according to Embodiment 3 differs from the battery according to Embodiment 1 in that the current collector protrudes from the active material layer on the side of the power generation element. Below, we will mainly explain the differences from Embodiment 1, and the explanation of the common points will be omitted or simplified.

[0138] Figure 8 is a cross-sectional view showing the cross-sectional configuration of the battery 301 according to this embodiment. As shown in Figure 8, the power generation element 10 of the battery 301 has battery cells 300 instead of battery cells 100, compared to the battery 1 shown in Figure 1.

[0139] Each of the multiple battery cells 300 includes an electrode layer 310, a counter electrode layer 320, and a solid electrolyte layer 130. The electrode layer 310 has an electrode current collector 311 and an electrode active material layer 112. The counter electrode layer 320 has a counter electrode current collector 321 and a counter electrode active material layer 122.

[0140] As shown in Figure 8, on the side surface 11, the counter electrode current collector 321 protrudes beyond the counter electrode active material layer 122. In this embodiment, on the side surface 11, the end faces of the counter electrode active material layer 122, the solid electrolyte layer 130, the electrode active material layer 112, and the electrode current collector 311 are flush and form a flat surface. The counter electrode current collector 321 protrudes outward from this flat surface. "Outward" refers to the direction away from the center of the power generation element 10, and for example, when the side surface 11 is used as the reference, it corresponds to the negative direction of the x-axis.

[0141] The protrusion of the counter electrode current collector 321 causes the counter electrode terminal 31 to contact the main surface of the protruding portion 321a of the counter electrode current collector 321. The protruding portion 321a is a part of the counter electrode current collector 321 and is located on the negative side of the x-axis, further than the end face on the negative x-axis side of the counter electrode active material layer 122. This increases the contact area between the counter electrode terminal 31 and the counter electrode current collector 321, thereby reducing the connection resistance.

[0142] The amount of protrusion of the counter electrode current collector 321, that is, the length of the protrusion 321a in the x-axis direction, is not particularly limited. For example, the amount of protrusion of the counter electrode current collector 321 is 4.5 times or more the thickness of the counter electrode current collector 321 (i.e., the length in the z-axis direction). As a result, in this embodiment, the counter electrode terminals 31 are in contact with both main surfaces of the protrusion 321a, so the contact area can be increased to more than 10 times compared to the case where the counter electrode current collector 321 does not protrude.

[0143] Alternatively, the amount of protrusion of the counter electrode current collector 321 may be 9 times or more the thickness of the counter electrode current collector 321. This makes it possible to increase the contact area by more than 10 times compared to the case where the counter electrode terminal 321 does not protrude, even when the counter electrode terminal 31 is in contact with only one side of the main surface of the protrusion 321a.

[0144] In this embodiment, the electrode current collector 311 has a similar configuration on the side surface 12. That is, on the side surface 12, the electrode current collector 311 protrudes beyond the electrode active material layer 112. In this embodiment, on the side surface 12, the end faces of the electrode active material layer 112, the solid electrolyte layer 130, the counter electrode active material layer 122, and the counter electrode current collector 321 are flush and form a flat surface. The electrode current collector 311 protrudes outward from this flat surface (specifically, in the positive direction of the x-axis).

[0145] The protrusion of the electrode current collector 311 causes the electrode terminal 32 to contact the main surface of the protruding portion 311a of the electrode current collector 311. The protruding portion 311a is a part of the electrode current collector 311 and is located on the positive x-axis side of the end face of the electrode active material layer 112 on the positive x-axis side. This increases the contact area between the electrode terminal 32 and the electrode current collector 311, thereby reducing the connection resistance.

[0146] The amount of protrusion of the electrode current collector 311, that is, the length of the protrusion 311a in the x-axis direction, is not particularly limited. For example, the amount of protrusion of the electrode current collector 311 may be 4.5 times or more the thickness of the electrode current collector 311, or it may be 9 times or more, similar to the counter electrode current collector 321.

[0147] The protrusions 311a and 321a are formed by not placing the counter electrode active material layer 122 or the electrode active material layer 112 at the ends of the current collector, respectively. Alternatively, they are formed by forming the counter electrode active material layer 122 or the electrode active material layer 112 over the entire surface of the current collector and then removing the ends. Removal can be performed, for example, by cutting only the current collector, polishing, sandblasting, brushing, etching, or plasma irradiation. Etching may be performed, for example, by laser etching, i.e., by laser irradiation. Alternatively, etching may be wet etching.

[0148] As described above, with the battery 301 according to this embodiment, the contact area between the current collector and the output terminal is increased, so the connection resistance between them is reduced. Therefore, the high-current characteristics of the battery 301 can be improved, and for example, rapid charging becomes possible.

[0149] In this embodiment, an example is shown in which the counter electrode current collector 321 and the electrode current collector 311 each protrude, but it is also possible for only one of them to protrude.

[0150] (Embodiment 4) Next, Embodiment 4 will be described.

[0151] The battery according to Embodiment 4 differs from the battery according to Embodiment 1 in that, on the side of the power generation element, the active material layer and other components not covered by the insulating layer are recessed relative to the current collector. Below, we will mainly explain the differences from Embodiment 1, and the explanation of the common points will be omitted or simplified.

[0152] Figure 9 is a cross-sectional view showing the cross-sectional configuration of the battery 401 according to this embodiment. As shown in Figure 9, the power generation element 10 of the battery 401 has a battery cell 400 instead of a battery cell 100, compared to the battery 1 shown in Figure 1.

[0153] Each of the multiple battery cells 400 includes an electrode layer 410, a counter electrode layer 420, and a solid electrolyte layer 430. The electrode layer 410 has an electrode current collector 111 and an electrode active material layer 412. The counter electrode layer 420 has a counter electrode current collector 121 and a counter electrode active material layer 422.

[0154] As shown in Figure 9, on the side surface 11, the counter electrode active material layer 422 is recessed compared to the electrode layer 410. Furthermore, the counter electrode active material layer 422 is recessed compared to the counter electrode current collector 121. Specifically, the counter electrode active material layer 422 is recessed inward compared to both the electrode layer 410 and the counter electrode current collector 121. "Inward" refers to the direction toward the center of the power generation element 10, and for example, when the side surface 11 is used as a reference, it corresponds to the positive x-axis direction.

[0155] In this embodiment, at least a portion of the solid electrolyte layer 430 is recessed from the electrode layer 410 on the side surface 11. Specifically, the portion of the end face of the solid electrolyte layer 430 that is not covered by the electrode insulating layer 21 is inclined obliquely with respect to the z-axis direction.

[0156] Because the counter electrode active material layer 422 is recessed, the counter electrode current collector 121 protrudes relatively. This protrusion of the counter electrode current collector 121 causes the counter electrode terminal 31 to contact the main surface of the protruding portion 421a of the counter electrode current collector 121. This increases the contact area between the counter electrode terminal 31 and the counter electrode current collector 121, thereby reducing their connection resistance.

[0157] The amount of recession of the counter electrode active material layer 422, that is, the amount of protrusion of the counter electrode current collector 121, is not particularly limited. For example, as in Embodiment 3, the amount of recession of the counter electrode active material layer 422 may be 4.5 times or more the thickness of the counter electrode current collector 121, or it may be 9 times or more.

[0158] In this embodiment, the electrode active material layer 412 has a similar configuration on the side surface 12. That is, on the side surface 12, the electrode active material layer 412 is recessed compared to the counter electrode layer 420. Furthermore, the electrode active material layer 412 is recessed compared to the electrode current collector 111. Specifically, the electrode active material layer 412 is recessed inward (specifically in the negative x-axis direction) compared to both the counter electrode layer 420 and the electrode current collector 111.

[0159] In this embodiment, at least a portion of the solid electrolyte layer 430 is recessed from the counter electrode layer 420 on the side surface 12. Specifically, the portion of the end face of the solid electrolyte layer 430 that is not covered by the counter electrode insulating layer 22 is inclined obliquely with respect to the z-axis direction.

[0160] Because the electrode active material layer 412 is recessed, the electrode current collector 111 protrudes relatively. This protrusion of the electrode current collector 111 causes the electrode terminal 32 to contact the main surface of the protruding portion 411a of the electrode current collector 111. This increases the contact area between the electrode terminal 32 and the electrode current collector 111, thereby reducing their connection resistance.

[0161] The amount of recession of the electrode active material layer 412, that is, the amount of protrusion of the electrode current collector 111, is not particularly limited. For example, as in Embodiment 3, the amount of recession of the electrode active material layer 412 may be 4.5 times or more the thickness of the electrode current collector 111, or 9 times or more.

[0162] The retreat of the active material layer is performed by the same method as the method used to make the current collector protrude in Embodiment 3. For example, the retreat of the active material layer is performed by cutting, polishing, sandblasting, brushing, etching, or plasma irradiation, leaving only the current collector. Etching may be performed, for example, by laser etching, i.e., by laser irradiation. Alternatively, etching may be performed by wet etching.

[0163] In this embodiment, in a plan view, the electrode current collector 111 and the counter electrode current collector 121 are the same size and shape, and their contours coincide. Therefore, as shown in Figure 9, in a cross-sectional view, the ends of the electrode current collector 111 and the counter electrode current collector 121 are aligned in the z-axis direction. As will be described in detail in the description of the manufacturing method, after forming a laminate by stacking multiple battery cells 100, the contours of the electrode current collector 111 and the counter electrode current collector 121 coincide by cutting the laminate all at once. Subsequently, the end faces of the active material layer are recessed to manufacture the battery 401 according to this embodiment. In this way, simultaneous processing of each battery cell 100, such as cutting all at once, can be performed, so that variations in the characteristics of each battery cell 100 can be suppressed.

[0164] As described above, with the battery 401 according to this embodiment, the contact area between the current collector and the output terminal is increased, so the connection resistance between them is reduced. Therefore, the high-current characteristics of the battery 401 can be improved, and for example, rapid charging becomes possible.

[0165] In this embodiment, an example is shown in which the counter electrode active material layer 422 and the electrode active material layer 412 are recessed, but only one of them may be recessed. Also, the solid electrolyte layer 430 does not need to be recessed on at least one of its sides 11 and 12.

[0166] (Embodiment 5) Next, Embodiment 5 will be described.

[0167] The battery according to Embodiment 5 differs from the battery according to Embodiment 1 in that it further includes a sealing member. Below, we will mainly explain the differences from Embodiment 1, and the explanation of the common points will be omitted or simplified.

[0168] Figure 10 is a cross-sectional view showing the cross-sectional configuration of the battery 501 according to this embodiment. As shown in Figure 10, the battery 501 includes a sealing member 540 in addition to the configuration of the battery 1 according to Embodiment 1.

[0169] The sealing member 540 exposes at least a portion of each of the counter electrode terminal 31 and the electrode terminal 32, and seals the power generation element 10. The sealing member 540 is provided such that, for example, the power generation element 10, the electrode insulating layer 21, and the counter electrode insulating layer 22 are not exposed.

[0170] The sealing member 540 is formed using, for example, an electrically insulating insulating material. As the insulating material, generally known materials for sealing members of batteries, such as encapsulants, may be used. As the insulating material, for example, a resin material may be used. The insulating material may be an insulating material that does not have ionic conductivity. For example, the insulating material may be at least one of epoxy resin, acrylic resin, polyimide resin, and silsesquioxane.

[0171] The sealing member 540 may include multiple different insulating materials. For example, the sealing member 540 may have a multilayer structure. Each layer of the multilayer structure may be formed using a different material and have different properties.

[0172] The sealing member 540 may contain particulate metal oxide material. Examples of metal oxide material include silicon oxide, aluminum oxide, titanium oxide, zinc oxide, cerium oxide, iron oxide, tungsten oxide, zirconium oxide, calcium oxide, zeolite, and glass. For example, the sealing member 540 may be formed using a resin material in which multiple particles made of metal oxide material are dispersed.

[0173] The particle size of the metal oxide material should be less than or equal to the distance between the electrode current collector 111 and the counter electrode current collector 121. The particle shape of the metal oxide material may be, for example, spherical, ellipsoidal, or rod-shaped, but is not limited to these.

[0174] The provision of the sealing member 540 improves the reliability of the battery 501 in various aspects, including mechanical strength, short-circuit prevention, and moisture resistance.

[0175] (modified version) Next, we will describe some variations of the embodiments described above.

[0176] In each modified example, the extent of the insulating layer covering the sides differs compared to the respective embodiments. Below, we will focus on explaining the differences from each embodiment, omitting or simplifying the explanation of the commonalities.

[0177] Figure 11 is a cross-sectional view showing the cross-sectional configuration of the battery 601 according to the first modified example. As shown in Figure 11, the battery 601, compared to the battery 1 according to the first embodiment, includes an electrode insulating layer 621 and a counter electrode insulating layer 622 instead of the electrode insulating layer 21 and the counter electrode insulating layer 22.

[0178] As shown in Figure 11, the electrode insulating layer 621 covers not only the electrode layer 110 but also a portion of the solid electrolyte layer 130 and the counter electrode layer 120 on the side surface 11. In other words, the electrode insulating layer 621 covers from the electrode layer 110 to a portion of the counter electrode layer 120. Specifically, the electrode insulating layer 621 covers a portion of the counter electrode active material layer 122. In this modified example, the electrode insulating layer 621 continuously covers at least a portion of the counter electrode active material layer 122 of one of two adjacent battery cells 100 to at least a portion of the counter electrode active material layer 122 of the other of the two adjacent battery cells 100. For example, the electrode insulating layer 621 completely covers one electrode current collector 111, the electrode active material layers 112 located on both sides of one electrode current collector 111, and the two solid electrolyte layers 130. For example, when the side surface 11 is viewed from above, the contour of the electrode insulating layer 621 overlaps with the counter electrode active material layer 122.

[0179] As a result, even if the width (length in the z-axis direction) of the electrode insulating layer 621 fluctuates due to manufacturing variations, the risk of exposing the electrode layer 110 is extremely low. Therefore, it is possible to suppress short circuits between the electrode layer 110 and the counter electrode layer 120 via the counter electrode terminal 31. In addition, as the electrode insulating layer 621 fits into the irregularities on the end face of the counter electrode active material layer 122, the adhesion strength of the electrode insulating layer 621 is improved, and the insulation reliability is enhanced.

[0180] Furthermore, the electrode insulating layer 621 may completely cover the counter electrode active material layer 122 on the side surface 11. Specifically, the contour of the electrode insulating layer 621 may overlap the boundary between the counter electrode active material layer 122 and the counter electrode current collector 121.

[0181] In this modified example, the counter electrode insulating layer 622 has a similar configuration on side surface 12. Specifically, on side surface 12, the counter electrode insulating layer 622 covers not only the counter electrode layer 120 but also a portion of the solid electrolyte layer 130 and the electrode layer 110. In other words, the counter electrode insulating layer 622 covers from the counter electrode layer 120 to a portion of the electrode layer 110. Specifically, the counter electrode insulating layer 622 covers a portion of the electrode active material layer 112. In this modified example, the counter electrode insulating layer 622 continuously covers from at least a portion of the electrode active material layer 112 of one of two adjacent battery cells 100 to at least a portion of the electrode active material layer 112 of the other of the two adjacent battery cells 100. For example, the counter electrode insulating layer 622 completely covers one counter electrode current collector 121, the counter electrode active material layers 122 located on both sides of one counter electrode current collector 121, and the two solid electrolyte layers 130.

[0182] For example, when the side surface 12 is viewed from above, the contour of the counter electrode insulating layer 622 overlaps with the electrode active material layer 112. As a result, even if the width (length in the z-axis direction) of the counter electrode insulating layer 622 fluctuates due to manufacturing variations, the risk of exposing the counter electrode layer 120 is extremely low. Therefore, it is possible to suppress short circuits between the counter electrode layer 120 and the electrode layer 110 via the electrode terminal 32. In addition, the adhesion strength of the counter electrode insulating layer 622 is improved as the counter electrode insulating layer 622 fits into the irregularities of the end face of the electrode active material layer 112, thereby improving insulation reliability.

[0183] Furthermore, the counter electrode insulating layer 622 may completely cover the electrode active material layer 112 on the side surface 12. Specifically, the contour of the counter electrode insulating layer 622 may overlap the boundary between the electrode active material layer 112 and the electrode current collector 111.

[0184] Figure 11 shows a modified example of the battery 1 according to Embodiment 1, but the electrode insulating layer 621 and counter electrode insulating layer 622 described above may also be applied to the battery 201 according to Embodiment 2, as shown in the battery 602 in Figure 12.

[0185] Figure 12 is a cross-sectional view showing the cross-sectional configuration of a battery 602 according to modified example 2. In the battery 602 shown in Figure 12, the electrode insulating layer 621 and the counter electrode conductive member 231 are in contact on the side surface 11. Specifically, the side surface 11 is completely covered by the electrode insulating layer 621 and the counter electrode conductive member 231 without any gaps. Therefore, the counter electrode terminal 31 is not in direct contact with the side surface 11.

[0186] Similarly, on side surface 12, the counter electrode insulating layer 622 and the electrode conductive member 232 are in contact. Specifically, side surface 12 is completely covered by the counter electrode insulating layer 622 and the electrode conductive member 232 without any gaps. Therefore, the electrode terminal 32 does not directly contact side surface 12.

[0187] In this case as well, the possibility of a short circuit between the electrode layer 110 and the counter electrode layer 120 can be sufficiently reduced, similar to the battery 501, thereby improving the reliability of the battery 602.

[0188] Furthermore, as shown in Figure 13, the electrode insulating layer 621 and counter electrode insulating layer 622 described above may be applied to the battery 401 according to Embodiment 4.

[0189] Figure 13 is a cross-sectional view showing the cross-sectional configuration of a battery 603 according to modified example 3. In the battery 603 shown in Figure 13, on side surface 11, the electrode insulating layer 621 covers up to a portion of the recessed counter electrode active material layer 422. On side surface 12, the counter electrode insulating layer 622 covers up to a portion of the recessed electrode active material layer 412.

[0190] In this case as well, the possibility of a short circuit between the electrode layer 410 and the counter electrode layer 420 can be sufficiently reduced, thereby improving the reliability of the battery 603.

[0191] (Manufacturing method) Next, a method for manufacturing batteries according to each of the embodiments and modified examples described above will be explained.

[0192] Figure 14 is a flowchart showing an example of a battery manufacturing method according to each embodiment or modification. Specifically, Figure 14 shows an example of a manufacturing method for batteries 301, 401, or 603 shown in Figures 8, 9, or 13. Below, an example of battery 401 will be described.

[0193] As shown in Figure 14, first, several battery cells are prepared (S10, first step). The battery cells to be prepared are, for example, battery cells 100A, 100B, and 100C shown in Figures 3A to 3C.

[0194] Next, multiple battery cells 100 are stacked (S20, second step). Specifically, a laminate is formed by stacking multiple battery cells 100 in order such that the order of the electrode layer 110, counter electrode layer 120, and solid electrolyte layer 130 alternates. In this embodiment, a power generation element 10 shown in Figure 4 is formed by stacking battery cells 100A, 100B, and 100C in appropriate combinations. The power generation element 10 is an example of a laminate.

[0195] Furthermore, after stacking multiple battery cells 100, the sides of the power generation element 10 may be flattened. For example, by cutting the stack of multiple battery cells 100 all at once, a power generation element 10 with flat sides can be formed. The cutting process can be performed, for example, by a blade, laser, or jet.

[0196] Next, an insulating layer is formed on the side surface of the power generation element 10 (S30, third step). Specifically, an electrode insulating layer 21 is formed on the side surface 11 to cover the electrode layer 110. Also, a counter electrode insulating layer 22 is formed on the side surface 12 to cover the counter electrode layer 120.

[0197] The electrode insulating layer 21 and the counter electrode insulating layer 22 are formed, for example, by coating and curing a fluid resin material. Coating is carried out by methods such as inkjet printing, spray printing, screen printing, or gravure printing. Curing is carried out by drying, heating, light irradiation, etc., depending on the resin material used.

[0198] Furthermore, when forming the electrode insulating layer 21 and the counter electrode insulating layer 22, a protective member may be formed in areas where the insulating layer should not be formed, such as by masking with tape or by resist treatment, so that the end faces of the counter electrode current collector 121 and the end faces of the electrode current collector 111 are not insulated. After the formation of the electrode insulating layer 21 and the counter electrode insulating layer 22, the conductivity of each current collector can be ensured by removing the protective member.

[0199] Next, the end face is recessed (S40, fifth step). Specifically, the end face of the active material layer of the power generation element 10 is recessed to make the current collector protrude beyond the active material layer. More specifically, on the side surface 11 of the power generation element 10, the counter electrode current collector 121, which is part of the counter electrode layer 120, protrudes beyond the counter electrode active material layer 122, which is another part of the counter electrode layer 120.

[0200] For example, the side surface 11 may be polished, sandblasted, brushed, etched, or plasma irradiated. In this case, etching may be performed by laser etching, i.e., laser irradiation. Alternatively, the etching may be wet etching. In this case, the electrode insulating layer 21 functions as a protective member for each process. For example, when sandblasting is performed on the side surface 11, the portion covered by the electrode insulating layer 21 is not polished, and the portion not covered by the electrode insulating layer 21, specifically the end face of the counter electrode layer 120, is scraped off and replaced. In this case, since the counter electrode active material layer 122 is more brittle than the counter electrode current collector 121, more of it is removed than the counter electrode current collector 121. As a result, the counter electrode active material layer 122 recedes beyond the counter electrode current collector 121. That is, as shown in Figure 9, a counter electrode active material layer 422 with a receding end face is formed. In other words, the counter electrode current collector 121 protrudes beyond the counter electrode active material layer 422.

[0201] By performing the same process on the side surface 12, the electrode active material layer 112 recedes relative to the electrode current collector 111. That is, as shown in Figure 9, an electrode active material layer 412 with a receding end surface is formed. In other words, the electrode current collector 111 protrudes more than the electrode active material layer 412.

[0202] Next, extraction terminals are formed on the side surface of the power generation element 10 (S50, fourth step). Specifically, on side surface 11, a counter electrode terminal 31 is formed to electrically connect multiple counter electrode layers 120. On side surface 12, an electrode terminal 32 is formed to electrically connect multiple electrode layers 110.

[0203] For example, the counter electrode terminal 31 is formed by coating and curing a conductive resin so as to cover the electrode insulating layer 21 and the portion of the side surface 11 not covered by the electrode insulating layer 21. Similarly, the electrode terminal 32 is positioned by coating and curing a conductive resin so as to cover the counter electrode insulating layer 22 and the portion of the side surface 12 not covered by the counter electrode insulating layer 22. The counter electrode terminal 31 and electrode terminal 32 may also be formed by methods such as printing, plating, vapor deposition, sputtering, welding, soldering, joining, or other methods.

[0204] Through the above process, the battery 401 shown in Figure 9 can be manufactured.

[0205] In addition, the process of pressing the multiple battery cells 100 prepared in step S10 individually, or after stacking the multiple battery cells, in the stacking direction may be performed.

[0206] In the example shown in Figure 14, the end face setback process (S40) is performed after the formation of the insulating layer (S30) and before the formation of the extraction terminals (S50), but it is not limited to this. For example, after performing the end face setback process on each of the multiple battery cells 100 prepared in step S10, the stacking of each battery cell 100 (S20) may be performed. For example, the current collector can be made to protrude beyond the active material layer by partial cutting that leaves only the current collector.

[0207] Furthermore, as shown in Figure 15, the end face setback process (S40) may not be performed. Figure 15 is a flowchart showing another example of a battery manufacturing method according to each embodiment or each modified example. Specifically, Figure 15 shows an example of a manufacturing method for battery 1 shown in Figure 1 or battery 601 shown in Figure 11.

[0208] Furthermore, after the formation of the laminate (S20) and before the formation of the extraction terminals (S50), the counter electrode conductive member 231 and the electrode conductive member 232 shown in Figure 7 or Figure 12 may be formed. The counter electrode conductive member 231 and the electrode conductive member 232 may be formed by, for example, printing, plating, vapor deposition, sputtering, welding, soldering, joining, or other methods.

[0209] Furthermore, after forming the extraction terminals (S50), the sealing member 540 shown in Figure 10 may be formed. The sealing member 540 is formed, for example, by coating and curing a fluid resin material. Coating is carried out by methods such as inkjet printing, spray printing, screen printing, or gravure printing. Curing is carried out by drying, heating, light irradiation, etc., depending on the resin material used.

[0210] (Other embodiments) Although one or more embodiments of batteries and methods for manufacturing batteries have been described above based on embodiments, this disclosure is not limited to these embodiments. Within the scope of this disclosure, various modifications to these embodiments that a person skilled in the art could conceive, as well as forms constructed by combining components from different embodiments, are also included.

[0211] For example, in the above embodiment, an example was described in which terminal electrodes are provided on each of the sides 11 and 12, but terminal electrodes may also be provided on each of the sides 13 and 14. In other words, side 13 may be an example of a first side, and side 14 may be an example of a second side. Also, terminal electrodes may be provided on one of the sides 11 and 12 and on one of the sides 13 and 14. In other words, terminal electrodes may be provided along two adjacent sides of the main surface 15.

[0212] Furthermore, multiple terminal electrodes of the same polarity may be provided on each side. For example, terminal electrodes connected to the counter electrode layer may be provided on each of two adjacent sides, and terminal electrodes connected to the electrode layer may be provided on each of the remaining two adjacent sides. Alternatively, terminal electrodes connected to the counter electrode layer may be provided on two opposing sides, and terminal electrodes connected to the electrode layer may be provided on each of the remaining two opposing sides.

[0213] Furthermore, although the above embodiment describes an example in which two adjacent electrode cells share a current collector, the current collector does not necessarily have to be shared. Specifically, multiple battery cells 100A, as shown in Figure 3A, may be stacked side by side. In this case, two current collectors of the same polarity are superimposed. At this time, the two current collectors may be superimposed in direct contact, or they may be superimposed via a conductive material or an adhesive material.

[0214] Furthermore, external electrodes may be formed on the outermost surface of each of the electrode terminals and counter electrode terminals by methods such as plating, printing, or soldering. By including external electrodes in the battery, the mountability of the battery can be further improved.

[0215] Furthermore, although the above embodiment shows an example in which each battery has both a counter electrode terminal 31 and an electrode terminal 32, it may also have only one of them. In other words, the extraction of one of the positive or negative electrodes of the battery may be performed by a tab electrode.

[0216] Furthermore, each of the above embodiments may be modified, replaced, added, or omitted in various ways within the scope of the claims or their equivalents. [Industrial applicability]

[0217] This disclosure can be used, for example, as a battery for electronic devices, electrical appliances, and electric vehicles. [Explanation of Symbols]

[0218] 1, 201, 301, 401, 501, 601, 602, 603 batteries 10 Power generation elements 11, 12, 13, 14 Side view 15, 16 Main surface 21, 621 Electrode insulating layer 22,622 Counter electrode insulating layer 31 Counter terminal 32 Electrode terminal 100, 100A, 100B, 100C, 300, 400 battery cells 110, 110B, 310, 410 electrode layer 111, 311 Electrode current collector 112, 412 Electrode active material layer 120, 120C, 320, 420 Counter pole layers 121, 321 Counter-pole current collector 122, 422 Counter electrode active material layer 130, 430 solid electrolyte layer 231 Counter electrode conductive member 232 Electrode conductive material 311a, 321a, 411a, 421a protrusion 540 Sealing member

Claims

1. A power generation element having a plurality of battery cells, each containing an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, wherein the plurality of battery cells are electrically connected in parallel and stacked, On the first side surface of the power generation element, a first insulating member covering the electrode layer and The first side surface and the first insulating member are covered, and the first terminal electrode is electrically connected to the counter electrode layer, Equipped with, The aforementioned counter electrode layer is Counter electrode current collector and It comprises a counter electrode active material layer located between the counter electrode current collector and the solid electrolyte layer, In the first side, the counter electrode current collector protrudes more than the counter electrode active material layer. The first terminal electrode is in contact with the main surface of the counter electrode current collector. battery.

2. In the first aspect, the counter electrode active material layer is recessed compared to the electrode layer. The battery according to claim 1.

3. The end face on the first side of the counter electrode current collector and the end face on the first side of the electrode layer coincide when viewed from a direction perpendicular to the main surface of the power generation element. The battery according to claim 1 or 2.

4. The thickness of the counter electrode current collector is 20 μm or less. The battery according to any one of claims 1 to 3.

5. The first insulating member covers at least a portion of the solid electrolyte layer on the first side surface. The battery according to any one of claims 1 to 4.

6. A power generation element having a plurality of battery cells, each containing an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, wherein the plurality of battery cells are electrically connected in parallel and stacked, On the first side surface of the power generation element, a first insulating member covering the electrode layer and The first side surface and the first insulating member are covered, and the first terminal electrode is electrically connected to the counter electrode layer, Equipped with, The first insulating member covers at least a portion of the solid electrolyte layer on the first side surface, The first insulating member, on its first side surface, covers from the electrode layer to a portion of the counter electrode layer along the stacking direction of the power generation element, battery.

7. A power generation element having a plurality of battery cells, each containing an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, wherein the plurality of battery cells are electrically connected in parallel and stacked, On the first side surface of the power generation element, a first insulating member covering the electrode layer and The first side surface and the first insulating member are covered, and the first terminal electrode is electrically connected to the counter electrode layer, The first side surface comprises a conductive member covering at least a portion of the counter electrode layer, The first terminal electrode further covers the conductive member, battery.

8. The first insulating member covers the electrode layer of each of the plurality of battery cells on its first side surface. The first terminal electrode is electrically connected to the counter electrode layer of each of the plurality of battery cells. The battery according to any one of claims 1 to 7.

9. A power generation element having a plurality of battery cells, each containing an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, wherein the plurality of battery cells are electrically connected in parallel and stacked, On the first side surface of the power generation element, a first insulating member covering the electrode layer and The first side surface and the first insulating member are covered, and the first terminal electrode is electrically connected to the counter electrode layer, Equipped with, The first insulating member covers the electrode layer of each of the plurality of battery cells on its first side surface. The first terminal electrode is electrically connected to the counter electrode layer of each of the plurality of battery cells. The first insulating member has a stripe shape in a plan view of the first side surface. battery.

10. On the second side of the power generation element, a second insulating member covering the counter electrode layer, The system further comprises a second terminal electrode that covers the second side surface and the second insulating member and is electrically connected to the electrode layer, The battery according to any one of claims 1 to 9.

11. A power generation element having a plurality of battery cells, each containing an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, wherein the plurality of battery cells are electrically connected in parallel and stacked, On the first side surface of the power generation element, a first insulating member covering the electrode layer and The first side surface and the first insulating member are covered, and the first terminal electrode is electrically connected to the counter electrode layer, On the second side of the power generation element, a second insulating member covering the counter electrode layer, The second side surface and the second insulating member are covered, and the second terminal electrode is electrically connected to the electrode layer, Equipped with, The electrode layer is Electrode current collector and It comprises an electrode active material layer located between the electrode current collector and the solid electrolyte layer, In the second side view, the electrode current collector protrudes more than the electrode active material layer. The second terminal electrode is in contact with the main surface of the electrode current collector. battery.

12. In the second aspect, the electrode active material layer is recessed compared to the counter electrode layer. The battery according to claim 11.

13. The second insulating member covers the counter electrode layer of each of the plurality of battery cells on its second side surface. The second terminal electrode is electrically connected to the electrode layer of each of the plurality of battery cells. The battery according to any one of claims 10 to 12.

14. The first insulating member includes resin, The battery according to any one of claims 1 to 13.

15. The system further comprises a sealing member that exposes at least a portion of the first terminal electrode and seals the power generation element. The battery according to any one of claims 1 to 14.

16. A first step is to prepare a plurality of battery cells, each containing an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer. A second step is to form a laminate by sequentially stacking the plurality of battery cells such that the order of the electrode layer, the counter electrode layer, and the solid electrolyte layer alternates, A third step involves covering one side of the laminate with an insulating material, A fourth step involves covering the aforementioned side surface and the insulating member with terminal electrodes electrically connected to the counter electrode layer, The fifth step includes, in one of the aforementioned aspects, causing a portion of the counter electrode layer to protrude from another portion of the counter electrode layer, Battery manufacturing method.

17. The fifth step is performed after the third step and before the fourth step. The method for manufacturing a battery according to claim 16.

18. The fifth step is performed by partially cutting, polishing, sandblasting, brushing, etching, or plasma irradiation of one side surface. A method for manufacturing a battery according to claim 16 or 17.

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