Battery and method for manufacturing a battery

Abstract

A battery (1) comprises: a power generation element (5) that has a structure that is formed by layering a plurality of power generation layers (100) and a plurality of collectors (50); and a counter electrode terminal (31). Each of the plurality of power generation layers (100) is sandwiched between two adjacent collectors (50) from among the plurality of collectors (50). The plurality of collectors (50) do not contact each other. At least one collector (50) from among the plurality of collectors (50) has: a protruding part (51) that protrudes beyond end surfaces (80) of the power generation layers (100) at a side surface part (11) of the power generation element (5); and a layering part (55) that is where the plurality of power generation layers (100) are layered. When the protruding part (51) and the layering part (55) are projected onto a projection plane (P1) that is orthogonal to the principal surfaces of the plurality of power generation layers (100), the projected area of the protruding part (51) is larger than the projected area of the layering part (55). The counter electrode (31) is connected to a principal surface of the protruding part (51).

Description

【Technical Field】 【0008】 , , , , , , 【0006】 , , , , , , 【0005】 , , , , , , 【0007】 , , 【0009】 , , , 【0001】 The present disclosure relates to a battery and a method for manufacturing the same. 【Background Art】 【0002】 Patent Document 1 discloses a battery in which a plurality of unit cells connected in series and stacked are connected in parallel at end faces. 【0003】 Patent Document 2 discloses a battery in which a current collector is protruded to connect a plurality of unit cells connected in series and stacked in parallel at end faces. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2013-120717 【Patent Document 2】 Japanese Patent Application Laid-Open No. 2008-198492 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 In the prior art, further improvement in the high-current characteristics and reliability of the battery is desired. 【0006】 In a stacked battery, it is important to achieve a high energy density while making a highly convenient and reliable connection using single cells, which are the stacked unit cells. 【0007】 On the other hand, since the unit cells constituting the stacked battery are thin, it is difficult to secure a connection area at the end faces. 【0008】 Therefore, the present disclosure provides a high-performance battery and a method for manufacturing the same. 【Means for Solving the Problems】 【0009】 A battery according to one aspect of the present disclosure comprises a power generation element having a structure in which a plurality of power generation layers and a plurality of current collectors are stacked, and a conductive member, each of the plurality of power generation layers having an electrode layer, a counter electrode layer and a solid electrolyte layer located between the electrode layer and the counter electrode layer, and sandwiched between two adjacent current collectors of the plurality of current collectors, the two adjacent power generation layers of the plurality of power generation layers are stacked via one of the current collectors of the plurality of current collectors, the plurality of current collectors are not in contact with each other, and at least one of the plurality of current collectors is located on the side surface of the power generation element, the plurality of power generation The device includes a protruding portion that extends from the end face of the electrostatic layer, and a laminated portion located on the end face side of the protruding portion and connected to the protruding portion, which is a portion where the plurality of power generation layers are laminated. When the protruding portion and the laminated portion are projected from the outside of the side portion along a direction parallel to the main faces of the plurality of power generation layers with respect to a projection plane perpendicular to the main faces of the plurality of power generation layers, the projected area of ​​the protruding portion is larger than the projected area of ​​the laminated portion, the conductive member is connected to the main face of the protruding portion, and the conductive member is in contact with the end face of the electrode layer or counter electrode layer adjacent to the at least one current collector on the side portion. 【0010】 A method for manufacturing a battery according to one aspect of the present disclosure includes: a first step of preparing a plurality of unit cells, each having a structure in which a power generation layer having an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, and a current collector layer are laminated; and a second step of forming a power generation element in which a plurality of power generation layers and a plurality of current collectors, each containing the current collector layer, are laminated, wherein the power generation layer is sandwiched between two adjacent current collectors from the plurality of current collectors, and the two adjacent power generation layers are laminated via one of the plurality of current collectors, and the plurality of current collectors are not in contact with each other, wherein the plurality of unit cells are laminated, and at least one of the plurality of current collectors has a side portion of the power generation element The process includes a second step of forming a protrusion that protrudes from the end face of the power generation layer, and a third step of forming a conductive member connected to the main surface of the protrusion and in contact with the end face of the electrode layer or the counter electrode layer adjacent to the at least one current collector on the side surface, wherein in the second step, when projecting the protrusion and the stacked portion of the at least one current collector, which is located on the end face side of the protrusion and connected to the protrusion and where the power generation layer is stacked, from the outside of the side surface along a direction parallel to the main surface of the power generation layer, onto a projection plane perpendicular to the main surface of the power generation layer, the projected area of ​​the protrusion is formed such that it is larger than the projected area of ​​the stacked portion. [Effects of the Invention] 【0011】 This disclosure provides a high-performance battery and a method for manufacturing the same. [Brief explanation of the drawing] 【0012】 [Figure 1] Figure 1 is a cross-sectional view 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 3] Figure 3 is a cross-sectional view illustrating the detailed structure of the current collector of the battery according to Embodiment 1. [Figure 4]FIG. 4 is a diagram for explaining the projected area of the current collector of the battery according to Embodiment 1. [Figure 5] FIG. 5 is a plan view of the power generation element of the battery according to Embodiment 1 as viewed from the side. [Figure 6] FIG. 6 is a cross-sectional view of the power generation element of the battery according to Embodiment 1. [Figure 7] FIG. 7 is another plan view of the power generation element of the battery according to Embodiment 1 as viewed from the side. [Figure 8] FIG. 8 is a plan view showing the positional relationship between the side surface portion of the power generation element according to Embodiment 1 and the electrode insulating layer provided on the side surface portion. [Figure 9] FIG. 9 is a plan view showing the positional relationship between the side surface portion of the power generation element according to Embodiment 1, the electrode insulating layer provided on the side surface portion, and the counter electrode terminal. [Figure 10] FIG. 10 is a plan view showing the positional relationship between the side surface portion of the power generation element according to a modification of Embodiment 1 and the electrode insulating layer provided on the side surface portion. [Figure 11] FIG. 11 is a plan view of the battery according to a modification of Embodiment 1 as viewed from the side. [Figure 12] FIG. 12 is a cross-sectional view of the battery according to Embodiment 2. [Figure 13] FIG. 13 is a cross-sectional view of the battery according to Embodiment 3. [Figure 14] FIG. 14 is a cross-sectional view of the battery according to Embodiment 4. [Figure 15] FIG. 15 is a cross-sectional view for explaining the detailed structure of the current collector of the battery according to Embodiment 4. [Figure 16] FIG. 16 is a cross-sectional view of the battery according to Embodiment 5. [Figure 17] FIG. 17 is a cross-sectional view for explaining the detailed structure of the current collector of the battery according to Embodiment 5. [Figure 18] FIG. 18 is a cross-sectional view of the battery according to Embodiment 6. [Figure 19] FIG. 19 is a cross-sectional view for explaining the detailed structure of the current collector of the battery according to Embodiment 6. [Figure 20]FIG. 20 is a cross-sectional view of the battery according to Embodiment 7. [Figure 21] FIG. 21 is a cross-sectional view of the battery according to Embodiment 8. [Figure 22] FIG. 22 is a plan view showing the positional relationship between the side surface portion of the power generation element according to Embodiment 8, the insulating layer provided on the side surface portion, and the connection terminals. [Figure 23] FIG. 23 is a plan view when the battery according to the modified example of Embodiment 8 is viewed from the side. [Figure 24] FIG. 24 is a flowchart showing Manufacturing Method Example 1 of the battery according to the embodiment. [Figure 25A] FIG. 25A is a cross-sectional view of an example of a unit cell according to the embodiment. [Figure 25B] FIG. 25B is a cross-sectional view of another example of a unit cell according to the embodiment. [Figure 25C] FIG. 25C is a cross-sectional view of another example of a unit cell according to the embodiment. [Figure 26] FIG. 26 is a flowchart showing Manufacturing Method Example 2 of the battery according to the embodiment. [Figure 27] FIG. 27 is a flowchart showing Manufacturing Method Example 3 of the battery according to the embodiment. 【Embodiments for Carrying Out the Invention】 【0013】 (Summary of the Present Disclosure) Examples of the battery and the manufacturing method of the battery according to the present disclosure are shown below. 【0014】 A battery according to a first aspect of the present disclosure comprises a power generation element having a structure in which a plurality of power generation layers and a plurality of current collectors are stacked, and a conductive member, each of the plurality of power generation layers having an electrode layer, a counter electrode layer and a solid electrolyte layer located between the electrode layer and the counter electrode layer, and sandwiched between two adjacent current collectors of the plurality of current collectors, the two adjacent power generation layers of the plurality of power generation layers are stacked via one of the current collectors of the plurality of current collectors, the plurality of current collectors are not in contact with each other, and at least one of the plurality of current collectors is located on the side surface of the power generation element, the plurality of power generation The device includes a protruding portion that extends from the end face of the electrostatic layer, and a laminated portion located on the end face side of the protruding portion and connected to the protruding portion, which is a portion where the plurality of power generation layers are laminated. When the protruding portion and the laminated portion are projected from the outside of the side portion along a direction parallel to the main faces of the plurality of power generation layers with respect to a projection plane perpendicular to the main faces of the plurality of power generation layers, the projected area of ​​the protruding portion is larger than the projected area of ​​the laminated portion, the conductive member is connected to the main face of the protruding portion, and the conductive member is in contact with the end face of the electrode layer or counter electrode layer adjacent to the at least one current collector on the side portion. 【0015】 This makes it possible to create high-performance batteries. For example, batteries with improved reliability, energy density, and high-current characteristics can be realized. 【0016】 Specifically, because the protrusion extends beyond the end face of the power generation layer, a conductive member for extracting current can be connected to the main surface of the protrusion. Therefore, compared to the case where the conductive member is connected to the end face of the current collector, the connection area between the conductive member and the current collector can be increased, and the resistance of the connection part can be reduced, thereby suppressing voltage drop and heat generation at the connection part and improving high-current characteristics. In addition, the increased connection area between the conductive member and the current collector increases the mechanical connection strength between the conductive member and the current collector, thereby improving the reliability of the battery. Furthermore, because the conductive member is in contact with the electrode layer or counter electrode layer, the reliability of the battery's electrical connection is improved, and the protrusion is stably held by the conductive member, improving the mechanical strength of the battery. 【0017】 Furthermore, the projected area of ​​the protruding portion is larger than the projected area of ​​the laminated portion, resulting in a structure where the protruding portion extends further in the laminated direction than the laminated portion. Therefore, when the protruding portion is connected to a conductive member, the protruding portion can bite into the conductive member, strengthening the mechanical connection between the current collector and the conductive member through an anchoring effect. Also, when comparing cases where the height from the end face of the power generation layer to the tip of the protruding portion is the same, the area of ​​the main surface of the protruding portion is larger than when the projected area of ​​the protruding portion is the same as the projected area of ​​the laminated portion. As a result, the connection area when connecting a conductive member to the main surface of the protruding portion can be increased. In other words, the connection area when connecting a conductive member to the main surface of the protruding portion can be increased without increasing the overall size of the battery. Thus, both high energy density and high current characteristics can be achieved. 【0018】 Furthermore, for example, in a second embodiment of this disclosure, the battery according to the first embodiment may have the protruding portion bent or curved. 【0019】 This makes it easy to form protrusions with a large projected area. 【0020】 Furthermore, for example, in a third embodiment of this disclosure, in the battery according to the second embodiment, the maximum angle of bending or curvature in the protruding portion may be 90 degrees or less with respect to the stacked portion. 【0021】 This makes it easy to form conductive members that connect to the protruding parts. 【0022】 Furthermore, for example, in a fourth embodiment of this disclosure, in the battery according to the second embodiment, the maximum angle of bending or curvature in the protruding portion may be 1 degree or more and 45 degrees or less with respect to the stacked portion. 【0023】 This allows for easy formation of conductive members connected to the protruding portions, and also increases the mechanical connection strength between the current collector and the conductive members. 【0024】 Furthermore, for example, in a fifth embodiment of this disclosure, in the battery according to the first embodiment, the protruding portion may have a portion that is thicker than the laminated portion. 【0025】 This makes it possible to increase the projected area of ​​the protrusion while reducing the electrical resistance of the protrusion itself. 【0026】 Furthermore, for example, in the sixth aspect of this disclosure, in the battery according to the fifth aspect, the maximum thickness of the portion with a large thickness in the protruding portion may be 1.5 times or more the thickness of the laminated portion. 【0027】 This effectively increases the mechanical connection strength and connection area between the current collector and the conductive member. 【0028】 Furthermore, for example, in the seventh aspect of this disclosure, the battery according to the first aspect may have branched projections. 【0029】 This makes it easier to increase the surface area of ​​the protruding portion, and effectively increases the contact area between the protruding portion and the conductive member. 【0030】 Furthermore, for example, in the eighth aspect of this disclosure, in a battery according to any one of the first to seventh aspects, the side portion may have regions on both sides of the protruding portion in a direction parallel to the main surfaces of the plurality of power generation layers on the side portion, in which at least one current collector does not protrude beyond the end faces of the plurality of power generation layers. 【0031】 As a result, both sides of the protrusion are supported by the power generation layer, making it difficult for the protrusion to move and moderately restricting its degree of freedom of movement. Therefore, short circuits caused by the protrusion moving and coming into contact with each other during the battery manufacturing process are suppressed. 【0032】 Furthermore, for example, in the ninth embodiment of this disclosure, in a battery according to any one of the first to eighth embodiments, the protruding length of the protruding portion may be twice or more the thickness of the laminated portion. 【0033】 As a result, when the entire protruding portion is connected to the conductive member, it is possible to secure a connection area more than five times larger compared to when only the end face portion of the current collector is connected to the conductive member. 【0034】 Furthermore, for example, in the tenth embodiment of this disclosure, in a battery according to any one of the first to ninth embodiments, the height of the tip of the protrusion from the end face of the plurality of power generation layers may be less than or equal to the thickness of the power generation element. Furthermore, for example, in the eleventh embodiment of this disclosure, in a battery according to any one of the first to ninth embodiments, the height of the tip of the protrusion from the end face of the plurality of power generation layers may be less than or equal to twice the thickness of one of the plurality of power generation layers. 【0035】 This allows for miniaturization of the connection points of conductive components in the battery, thereby increasing the energy density of the battery. 【0036】 Furthermore, for example, in the twelfth aspect of this disclosure, in a battery according to any one of the first to eleventh aspects, the plurality of power generation layers may be electrically connected in parallel. 【0037】 This makes it possible to create high-capacity batteries. 【0038】 Furthermore, for example, in the 13th aspect of this disclosure, in a battery according to any one of the first to 11 aspects, the plurality of power generation layers may be electrically connected in series. 【0039】 This makes it possible to create high-voltage batteries. 【0040】 Furthermore, for example, in a 14th embodiment of the present disclosure, in a battery according to the 12th embodiment, the plurality of current collectors include a counter electrode current collector electrically connected to the counter electrode layer and an electrode current collector electrically connected to the electrode layer, wherein at least one current collector is the counter electrode current collector, and the battery further comprises an insulating member covering the electrode layer and the electrode current collector on the side surface, and the conductive member covering the insulating member on the side surface and connected to the protrusion of the counter electrode current collector. 【0041】 As a result, the insulating material covers the electrode layer and the electrode current collector on the side surface, which suppresses the occurrence of short circuits between the counter electrode layer and the electrode layer via the conductive material. 【0042】 Furthermore, for example, in the 15th embodiment of this disclosure, in the battery according to the 14th embodiment, the insulating member may be in contact with at least a portion of the solid electrolyte layer on the side surface. 【0043】 This allows the insulating material to be formed so that it makes contact with a portion of the solid electrolyte layer, thus preventing the electrode layer from being exposed without being covered by the insulating material, even if there are variations in the size of the insulating material. Furthermore, since the solid electrolyte layer is generally made of powdered material, there are very fine irregularities on its sides. This improves the adhesion strength of the insulating material and enhances the insulation reliability. 【0044】 Furthermore, for example, in a 16th aspect of this disclosure, in a battery according to the 14th or 15th aspect, the insulating member may, on its side surface, cover the electrode layer of each of the plurality of power generation layers and the electrode current collector that is electrically connected to the electrode layer of each of the plurality of power generation layers, and the conductive member may, on its side surface, be connected to the counter electrode current collector that is electrically connected to the counter electrode layer of each of the plurality of power generation layers. 【0045】 This allows conductive materials to be used for the parallel connection of multiple power generation layers. Since the conductive materials can be closely attached to the side surfaces and insulating materials, the volume of the parts involved in the parallel connection can be reduced. As a result, the energy density of the battery can be increased. 【0046】 Furthermore, a method for manufacturing a battery according to a 17th aspect of this disclosure includes a first step of preparing a plurality of unit cells, each having a structure in which a power generation layer having an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, and a current collector layer are laminated; and a second step of forming a power generation element in which a plurality of power generation layers and a plurality of current collectors, each containing the current collector layer, are laminated, wherein the power generation layer is sandwiched between two adjacent current collectors from the plurality of current collectors, and the two adjacent power generation layers are laminated via one of the plurality of current collectors, and the plurality of current collectors are non-contact with each other, wherein the plurality of unit cells are laminated, and the side of the power generation element is attached to at least one of the plurality of current collectors. The process includes a second step of forming a protrusion that protrudes from the end face of the power generation layer in a portion of the material, and a third step of forming a conductive member that is connected to the main surface of the protrusion and in contact with the end face of the electrode layer or the counter electrode layer adjacent to the at least one current collector in the side portion, wherein in the second step, when projecting the protrusion and the stacked portion of the at least one current collector, which is located on the end face side of the protrusion and connected to the protrusion and where the power generation layer is stacked, from the outside of the side portion along a direction parallel to the main surface of the power generation layer, with respect to a projection plane perpendicular to the main surface of the power generation layer, the projected area of ​​the protrusion is formed such that it is larger than the projected area of ​​the stacked portion. 【0047】 This makes it possible to manufacture the high-performance batteries mentioned above. 【0048】 Furthermore, for example, in the 17th aspect of this disclosure, in the battery manufacturing method according to the 16th aspect, the protrusion may be formed in the second step by using at least one of the following methods: dissolving the material, partial cutting, polishing, sandblasting, brushing, etching, plasma irradiation, laser irradiation, mechanical cutting, ultrasonic cutting, and pressing. 【0049】 This makes it easy to form protrusions. 【0050】 Embodiments of the present disclosure will be described below with reference to the drawings. 【0051】 The embodiments described below are all general 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. 【0052】 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. 【0053】 Furthermore, in this specification, terms indicating relationships between elements such as parallelism, terms indicating the shape of elements such as rectangles, and numerical ranges do not represent only strict meanings, but also include substantially equivalent ranges, such as differences of a few percent. 【0054】 In this specification and in the drawings, the x, y, and z axes represent the three axes of a three-dimensional Cartesian coordinate system. The x and y axes are the directions parallel 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 is the stacking direction of the multiple power generation layers included in the power generation element. In this specification, the "stacking direction" coincides with the direction normal to the main surface of the current collector and the active material layer. In this specification, "plan view" means a view from a direction perpendicular to the main surface, unless otherwise specified. 【0055】 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." 【0056】 Furthermore, in this specification, unless otherwise specified, "protruding" means protruding outward from the center of the power generation element in a cross-sectional view perpendicular to the main surface of the power generation layer. "Element A protrudes from element B" means that, outward, the tip of element A protrudes further than the portion of element B adjacent to element A, that is, the tip of element A is further from the center of the power generation element than the portion of element B adjacent to element A. Elements include, for example, electrode layers, counter electrode layers, solid electrolyte layers, and current collectors. 【0057】 Furthermore, in this specification, ordinal numbers such as "first," "second," etc., do not mean the number or order of components unless otherwise specified, but are used to avoid confusion and to distinguish similar components. 【0058】 (Embodiment 1) First, the configuration of the battery according to Embodiment 1 will be described. 【0059】 Figure 1 is a cross-sectional view of a battery 1 according to Embodiment 1. As shown in Figure 1, the battery 1 comprises a power generation element 5, 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. 【0060】 First, the specific configuration of the power generation element 5 will be explained using Figures 1 and 2. Figure 2 is a top view of the power generation element 5 of the battery 1 according to this embodiment. Figure 1 is a cross-sectional view corresponding to the cross-section shown by line II in Figure 2. 【0061】 As shown in Figures 1 and 2, the power generation element 5 has a structure in which a plurality of power generation layers 100 and a plurality of current collectors 50 are stacked along the thickness direction of the plurality of power generation layers 100. 【0062】 As shown in Figure 2, the plan view shape of the power generation element 5 is, for example, rectangular. In other words, the approximate shape of the power generation element 5 is a flattened rectangular parallelepiped. Here, flattening means that the thickness (i.e., the length in the z-axis direction) is shorter than the length of each side of the main surface (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 5 may also be a square, hexagon, or octagon, or it may be circular or elliptical. Furthermore, the outer edge of the power generation element 5 in plan view may have irregularities. Note that in the drawings relating to this specification, in cross-sectional views such as Figure 1 and the side view described later, the thickness of each layer is exaggerated to make the layer structure of the power generation element 5 easier to understand. 【0063】 As shown in Figure 2, the power generation element 5 includes four side portions 11, 12, 13, and 14 and two main surfaces 15 and 16. The side portions 11, 12, 13, and 14 correspond to the side portions that connect the main surfaces when the power generation element 5 is viewed as a plate-like body. The side portions 11, 12, 13, and 14 are exposed on the lateral side in the direction of extension of the main surface of the power generation layer 100 (the direction perpendicular to the stacking direction) when the power generation element 5 is in a standalone state (in this embodiment, when the electrode insulating layer 21, counter electrode insulating layer 22, counter electrode terminal 31, and electrode terminal 32 are absent). Furthermore, the side portions 11, 12, 13, and 14 correspond to the ends of the multiple power generation layers 100 and multiple current collectors 50 in a direction perpendicular to the stacking direction. 【0064】 Side portions 11 and 12 face away from each other. Each side portion 11 and 12 includes each of the two parallel long sides of the main surface 15. 【0065】 Side sections 13 and 14 face away from each other. Each side section 13 and 14 includes each of the two parallel short sides of the main surface 15. 【0066】 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 5. Main surface 16 is the lowermost surface of the power generation element 5. Both main surfaces 15 and 16 are flat except at the ends. 【0067】 The details of each component included in power generation element 5 are described below. 【0068】 As shown in Figures 1 and 2, the power generation element 5 has a plurality of power generation layers 100 and a plurality of current collectors 50. The power generation layer 100 is the minimum configuration of the power generation section of the battery and is also called a unit cell. In some cases, the power generation layer 100 and the current collector 50 connected to the power generation layer 100 are collectively referred to as a unit cell. The plurality of power generation layers 100 are stacked so as to be electrically connected in parallel. In this embodiment, the plurality of power generation layers 100 are stacked so as to be electrically connected in parallel to all of the power generation layers 100 of the power generation element 5. In the illustrated example, the power generation element 5 has eight power generation layers 100, but is not limited to this. For example, the number of power generation layers 100 of the power generation element 5 may be an even number such as two or four, or an odd number such as three or five. 【0069】 Each of the multiple power generation layers 100 includes an electrode layer 110, a counter electrode layer 120, and a solid electrolyte layer 130. The electrode layer 110 and the counter electrode layer 120 each contain an active material and are also referred to as the electrode active material layer and the counter electrode active material layer. In each of the multiple power generation layers 100, the electrode layer 110, the solid electrolyte layer 130, and the counter electrode layer 120 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 power generation layer 100. The counter electrode layer 120 is the other of the positive and negative electrode layers of the power generation layer 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 power generation layers 100 are substantially identical to each other. In two adjacent power generation layers 100, the order of the layers constituting the power generation layer 100 is reversed. In other words, the multiple power generation layers 100 are stacked along the z-axis with the order of the layers constituting the power generation layer 100 alternating. As a result, the multiple power generation layers 100 are stacked so as to be electrically connected in parallel. In this embodiment, since the number of power generation layers 100 is even, the bottom layer and the top layer of the power generation element 5 are layers of the same polarity. 【0072】 Two adjacent power generation layers 100 of the multiple power generation layers 100 are stacked via one of the multiple current collectors 50. In addition, each of the multiple power generation layers 100 of the power generation element 5 is sandwiched between two adjacent current collectors 50 from the multiple current collectors 50. 【0073】 The multiple current collectors 50 include an electrode current collector 61 electrically connected to the electrode layer 110 and a counter electrode current collector 62 electrically connected to the counter electrode layer 120. In this specification, "electrically connected" means electrically connected so that they are substantially at the same potential, unless otherwise specified. The electrode layer 110 is laminated on at least one main surface of the electrode current collector 61 without an intervening solid electrolyte layer 130. The counter electrode layer 120 is laminated on at least one main surface of the counter electrode current collector 62 without an intervening solid electrolyte layer 130. 【0074】 Multiple current collectors 50 are not in contact with each other. Therefore, the electrode current collectors 61 are not in direct contact with each other, and multiple electrode current collectors 61 are electrically connected via electrode terminals 32 in order to connect multiple power generation layers 100 in parallel. Similarly, the counter electrode current collectors 62 are not in direct contact with each other, and multiple counter electrode current collectors 62 are electrically connected via counter electrode terminals 31 in order to connect multiple power generation layers 100 in parallel. As a result, compared to the case where the ends of the current collectors 50 are bundled together to form a parallel connection, there is no need to extend the ends of the current collectors 50, and therefore the connection structure can be made smaller. 【0075】 The current collector 50 is a conductive foil, plate, or mesh-like member. The current collector 50 may be, for example, a conductive thin film. In the example shown in Figure 1, the current collector 50 is composed of a single metal foil. The current collector 50 may have a multilayer structure of multiple current-collecting layers made of multiple metal foils or the like. In this case, the multiple current-collecting layers are laminated directly or via an intermediate layer. 【0076】 For example, metals such as stainless steel (SUS), aluminum (Al), copper (Cu), and nickel (Ni) can be used as materials for the current collector 50. The electrode current collector 61 and the counter electrode current collector 62 in multiple current collectors 50 may be formed using different materials. 【0077】 The thickness of the current collector 50 is, for example, 5 μm or more and 200 μm or less, but is not limited to this. 【0078】 The electrode layer 110 is in contact with the main surface of the electrode current collector 61. The electrode current collector 61 may also include a connecting layer containing a conductive material in the portion that contacts the electrode layer 110. The counter electrode layer 120 is in contact with the main surface of the counter electrode current collector 62. The counter electrode current collector 62 may also include a connecting layer containing a conductive material in the portion that contacts the counter electrode layer 120. 【0079】 The electrode layer 110 is located on the main surface of the electrode current collector 61. The electrode layer 110 includes, for example, a negative electrode active material as the electrode material. The electrode layer 110 is located opposite the counter electrode layer 120. 【0080】 As the negative electrode active material contained in the electrode layer 110, for example, graphite, metallic lithium, and other negative electrode active materials 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. 【0081】 Furthermore, as the material contained in the electrode layer 110, a solid electrolyte such as an inorganic solid electrolyte may be used. As the inorganic solid electrolyte, for example, a sulfide solid electrolyte or an oxide solid electrolyte may be used. As the sulfide solid electrolyte, for example, a mixture of lithium sulfide (Li2S) and phosphorus pentasulfide (P2S5) may be used. Furthermore, as the material contained in the electrode layer 110, a conductive agent such as acetylene black, or a binding binder such as polyvinylidene fluoride may be used. 【0082】 The electrode layer 110 is produced by applying a paste-like coating, which is made by kneading the materials containing the electrode layer 110 together with a solvent, onto the main surface of, for example, an electrode current collector 61, and drying it. In order to increase the density of the electrode layer 110, the electrode current collector 61 (also called an electrode plate) to which the electrode layer 110 has been coated may be pressed after drying. The thickness of the electrode layer 110 is, for example, 5 μm to 300 μm, but is not limited to this. 【0083】 The counter electrode layer 120 is located on the main surface of the counter electrode current collector 62. The counter electrode layer 120 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 layer 120 contains, for example, a positive electrode active material. 【0084】 As the positive electrode active material contained in the counter electrode layer 120, 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. 【0085】 Furthermore, as the material containing the counter electrode layer 120, 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 layer 120, a conductive agent such as acetylene black, or a binding binder such as polyvinylidene fluoride may be used. 【0086】 The counter electrode layer 120 is produced by kneading the materials containing the counter electrode layer 120 together with a solvent to create a paste-like coating, which is then applied to the main surface of, for example, the counter electrode current collector 62 and dried. To increase the density of the counter electrode layer 120, the counter electrode current collector 62 (also called the counter electrode plate) coated with the counter electrode layer 120 may be pressed after drying. The thickness of the counter electrode layer 120 is, for example, 5 μm to 300 μm, but is not limited to this. 【0087】 The solid electrolyte layer 130 is placed between the electrode layer 110 and the counter electrode layer 120. The solid electrolyte layer 130 is in contact with both the electrode layer 110 and the counter electrode layer 120. 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. 【0088】 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. 【0089】 In this embodiment, the electrode layer 110, the counter electrode layer 120, 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 layer 110, the counter electrode layer 120, and the solid electrolyte layer 130 may be smoothly curved together. 【0090】 Furthermore, in the power generation layer 100, for example, in a plan view, the shape and size of the electrode layer 110, the solid electrolyte layer 130, and the counter electrode layer 120 are all the same, and their contours coincide. Also, multiple power generation layers 100 are substantially the same size as each other. Specifically, after the laminate corresponding to the power generation element 5 is formed, the multiple power generation layers 100 are cut together, and then the side portions 11 and 12 are formed by processing the power generation layer 100 to recede from the current collector 50 and processing the ends of the current collector 50 to bend or curve. By aligning the cutting direction with the lamination direction and performing the receding process uniformly, multiple power generation layers 100 of the same size as each other can be formed. By using the single cutting and receding process, for example, there is no gradual increase or decrease in film thickness at the beginning and end of the coating of each layer, and the area of ​​the electrode layer 110, the counter electrode layer 120, and the solid electrolyte layer 130 is precisely determined. As a result, the capacity variation among the multiple power generation layers 100 is reduced, and the accuracy of the battery capacity can be improved. 【0091】 Here, the end structures of the power generation layer 100 and the current collector 50 will be described in detail using Figures 1, 3, and 4. 【0092】 Figure 3 is a cross-sectional view illustrating the detailed structure of the current collector 50 of the battery 1 according to this embodiment. Figure 4 is a diagram illustrating the projected area of ​​the current collector 50 of the battery 1 according to this embodiment. Figure 3 is a diagram showing one power generation layer 100 and two adjacent current collectors 50 on either side of the power generation layer 100 from among the multiple power generation layers 100 and multiple current collectors 50 in the power generation element 5 of the battery 1. Figure 4 also shows an enlarged view of the region of the current collector 50 outside of a hypothetical projection plane P1. 【0093】 As shown in Figures 1 and 3, the current collector 50 includes a protruding portion 51 that extends beyond the end face 80 of the multiple power generation layers 100 on its side surface 11, and a laminated portion 55 where the multiple power generation layers 100 are stacked. The protruding portion 51 and the laminated portion 55 are names given to different regions of a single current collector 50. At the end face 80, most of the electrode layer 110, solid electrolyte layer 130, and counter electrode layer 120 (e.g., 90% or more) are terminated. The end face 80 is, for example, a flat surface, but may have irregularities resulting from the manufacturing process of the battery 1, such as the stacking of the power generation layers 100 and the current collector 50, the cutting of the stacked laminate, and the formation of the protruding portion 51. 【0094】 Furthermore, the current collector 50 also includes protruding portions 51 that extend beyond the end faces 80 of the multiple power generation layers 100 in the side portion 12. In the following description, the protruding portion 51 in the side portion 11 will be explained as a representative example, but the protruding portion 51 in the side portion 12 has the same configuration as, for example, the protruding portion 51 in the side portion 11 to which the same description applies. 【0095】 Specifically, the protrusion 51 protrudes beyond the end face of the electrode layer 110 or counter electrode layer 120 at the end face 80 of the power generation layer 100 adjacent to the current collector 50. The protrusion 51 is, for example, a region of the current collector 50 that, when viewed along the stacking direction, is outside the end face of the electrode layer 110 or counter electrode layer 120 at the end face 80 of the power generation layer 100 adjacent to the current collector 50. The end face of the electrode layer 110 or counter electrode layer 120 at the end face 80 of the power generation layer 100 adjacent to the current collector 50 is the end face of the layer in the power generation layer 100 closest to the current collector 50. Specifically, the end face of the electrode layer 110 or counter electrode layer 120 at the end face 80 of the power generation layer 100 adjacent to the current collector 50 is the end face of the electrode layer 110 when the current collector 50 is an electrode current collector 61, and is the end face of the counter electrode layer 120 when the current collector 50 is a counter electrode current collector 62. 【0096】 The protruding portion 51 is bent. The protruding portion 51 may also be curved. The protruding portion 51 has an anchor portion 52 that extends beyond the laminated portion 55 in a direction perpendicular to the main surface of the power generation layer 100 (in the illustrated example, the z-axis direction) when the side portion 11 is viewed from the front along a direction parallel to the main surface of the power generation layer 100. The anchor portion 52 includes a portion of the protruding portion 51 that does not overlap with the laminated portion 55 when the side portion 11 or 12 is viewed from the outside along a direction parallel to the main surface of the power generation layer 100. The anchor portion 52 is formed by the bending or curving of the protruding portion 51. The anchor portion 52 may extend on the positive side in the z-axis direction, on the negative side in the z-axis direction, or on both the positive and negative sides in the z-axis direction. 【0097】 The protrusion 51 is bent at one point inward from its center. The center of the protrusion 51 is the position where the distance to the boundary between the protrusion 51 and the laminated portion 55 is the same as the distance to the tip of the protrusion 51. Note that the location and number of bent or curved points on the protrusion 51 are not limited to this example. For example, the current collector 50 may include protrusions 51a that are bent or curved at two or more points, as shown in Figure 1. The current collector 50 may also include protrusions 51b that are not bent or curved and extend in the same direction as the laminated portion 55, as shown in Figure 1. 【0098】 The main surface of the protrusion 51 is exposed when the power generation element 5 is in a standalone state. This allows the counter electrode terminal 31 or the electrode terminal 32 to be connected to the main surface of the protrusion 51. The main surface of the protrusion 51 may be covered by the electrode layer 110 or the counter electrode layer 120. In this case, the thickness of the electrode layer 110 or the counter electrode layer 120 is, for example, one-fifth or less of the thickness of the electrode layer 110 or the counter electrode layer 120 in the area laminated on the laminated portion 55. 【0099】 The laminated portion 55 is, for example, a region of the current collector 50 that is located on the end face 80 side of the protruding portion 51, connected to the protruding portion 51, and overlaps with the electrode layer 110 or counter electrode layer 120 of the power generation layer 100 adjacent to the current collector 50. The boundary between the protruding portion 51 and the laminated portion 55 is the position of the end face of the electrode layer 110 or counter electrode layer 120 at the end face 80 of the power generation layer 100 adjacent to the current collector 50, when viewed along the lamination direction. In this embodiment, if the main surface of the protruding portion 51 is thinly covered by the electrode layer 110 or counter electrode layer 120 as described above, the end of the electrode layer 110 or counter electrode layer 120 at the covered portion is not included in the end face 80. 【0100】 As shown in Figures 1, 3, and 4, when projecting the protruding portion 51 and the stacked portion 55 from the outside of the side portion 11 along a direction parallel to the main surface of the multiple power generation layers 100 onto a virtual projection plane P1 perpendicular to the main surface of the multiple power generation layers 100, the projected area 51s of the protruding portion 51 is larger than the projected area of ​​the stacked portion 55. In the examples shown in Figures 1, 2, and 4, the projection plane P1 is parallel to the z-axis and the y-axis. In other words, the projection plane P1 is perpendicular to the main surface of the multiple power generation layers 100 and parallel to the direction in which the side portion 11 extends in a direction parallel to the main surface of the multiple power generation layers 100. The white arrows shown in Figures 3 and 4 are examples of projection directions. In the illustrated examples, the projection direction is parallel to the x-axis, that is, perpendicular to the projection plane P1. 【0101】 As shown in Figure 4, the projected area of ​​the laminated portion 55 is equal to the cross-sectional area when the laminated portion 55 is cut in the thickness direction. On the other hand, the protruding portion 51 has an anchor portion 52 that extends beyond the laminated portion 55 and is formed by bending. It can also be said that the projected area of ​​the laminated portion 55 is the projected area of ​​the boundary between the laminated portion 55 and the protruding portion 51. Therefore, the projected area 51s of the protruding portion 51 is larger than the projected area of ​​the laminated portion 55 by the amount of the area onto which the anchor portion 52 is projected. In other words, the protruding portion 51 protrudes from the end face 80 such that its projected area is larger than that of the laminated portion 55. 【0102】 Thus, because the projected area 51s of the protrusion 51 is larger than the projected area of ​​the laminated portion 55, when the protrusion 51 is connected to the terminal, the protrusion 51 can bite into the terminal, and the mechanical connection between the current collector 50 and the terminal can be strengthened by the anchoring effect. Furthermore, when comparing the case where the height from the end face 80 of the power generation layer 100 to the tip of the protrusion 51 is the same, the surface area of ​​the protrusion 51 is larger than when the projected area 51s of the protrusion 51 is the same as the projected area of ​​the laminated portion 55. As a result, the connection area when connecting the protrusion 51 and the terminal can be increased. In other words, the connection area when connecting the protrusion 51 and the terminal can be increased without increasing the overall size of the battery 1. This results in the effect of reducing the electrical connection resistance and improving the mechanical connection strength between the protrusion 51 and the terminal. In addition, since the anchor portion 52 is formed by bending, a protrusion 51 with a large projected area 51s can be easily formed. 【0103】 Furthermore, when the protruding portion 51 is connected to an insulating member, the mechanical connection can be strengthened in the same way as when it is connected to a terminal, thereby improving the reliability of the battery 1. 【0104】 The maximum angle of bending or curvature at the protruding portion 51 is, for example, 90 degrees or less with respect to the laminated portion 55. This allows for easy formation of the counter electrode terminal 31 and the electrode terminal 32. Alternatively, the maximum angle of bending or curvature at the protruding portion 51 may be between 1 degree and 45 degrees with respect to the laminated portion. This allows for easy formation of the counter electrode terminal 31 and the electrode terminal 32, and also increases the mechanical connection strength between the counter electrode terminal 31 and the electrode terminal 32. 【0105】 The length of the protruding portion 51 that extends beyond the end face 80 is, for example, more than twice the thickness of the laminated portion 55. This ensures that when the entire protruding portion 51 is connected to the terminal, a connection area of ​​more than five times the size can be secured compared to when only the end face portion of the current collector 50 is connected to the terminal. Thus, the high-current characteristics of the battery 1 can be improved. Alternatively, the length of the protruding portion 51 that extends beyond the end face 80 may be more than 4.5 times the thickness of the laminated portion 55. This ensures that when the entire protruding portion 51 is connected to the terminal, a connection area of ​​more than ten times the size can be secured compared to when only the end face portion of the current collector 50 is connected to the terminal. In detail, the length of the protruding portion 51 that extends beyond the end face 80 is the shortest distance on the surface of the protruding portion 51 from the boundary between the protruding portion 51 and the laminated portion 55 to the tip of the protruding portion 51. 【0106】 The height of the tip of the projection 51 from the end face 80 of the power generation layer 100 is, for example, less than or equal to the thickness of the power generation element 5. This makes it possible to miniaturize the terminal connection points in the battery 1 and increase the energy density of the battery 1. The height of the tip of the projection 51 from the end face 80 of the power generation layer 100 may be less than or equal to twice the thickness of the power generation layer 100, or less than or equal to the thickness of the power generation layer 100. This further increases the energy density of the battery 1. Also, from the viewpoint of increasing the connection strength and connection area with the terminal, the height of the tip of the projection 51 from the end face 80 of the power generation layer 100 is, for example, more than half the thickness of the power generation layer 100. In the illustrated example, the height of the tip of the projection 51 from the end face 80 of the power generation layer 100 is the maximum distance between the end face 80 of the power generation layer 100 and the tip of the projection 51 in the x-axis direction. 【0107】 Next, the arrangement of the protrusions 51 on the side portion 11 will be described. Figure 5 is a plan view of the power generation element 5 of the battery 1 according to this embodiment, viewed from the side (positive side in the x-axis direction). Specifically, Figure 5 is a front view of the side portion 11 of the power generation element 5, viewed from the front. Also, Figure 5 is the same shape as when projected in the projection direction described above. Figure 6 is a cross-sectional view of the power generation element 5 of the battery 1 according to this embodiment. Figure 6 is a cross-sectional view at the position where the continuous region 92, which will be described later, is cut. Figure 6 shows the cross-section along the line VI-VI in Figure 5. Note that in Figure 5, the end faces of each layer appearing on the side portion 11 are given the same shading as the shading of each layer shown in the cross-section of Figure 1. This is also the case for the plan views from other sides, which will be described later. 【0108】 As shown in Figure 5, the side portion 11 has a protruding region 91 on which the protruding portion 51 of the current collector 50 is provided, and continuous regions 92 located on both sides of the protruding region 91 in a direction parallel to the main surfaces of the multiple power generation layers 100 on the side portion 11. As shown in Figure 6, the continuous region 92 is a region in which the current collector 50 does not protrude beyond the end faces 80a of the multiple power generation layers 100. In this way, by providing continuous regions 92 on both sides of the protruding portion 51, both sides of the protruding portion 51 are supported by the power generation layers 100, making it difficult for the protruding portion 51 to move, and the degree of freedom of movement of the protruding portion 51 is appropriately restricted. Therefore, in the manufacturing process of the battery 1, etc., the protruding portion 51, which is exposed before the terminals etc. are formed, moves in the stacking direction, and it is suppressed that the protruding portions 51 come into contact with each other and cause a short circuit. In addition, even if they do not come into contact, there is a possibility that a discharge short circuit may occur as the protruding portions 51 come close to each other, but for the same reason, a discharge short circuit can be suppressed. 【0109】 In the protruding region 91, each of the multiple power generation layers 100 is set back from the multiple current collectors 50, forming an end face 80 that is recessed from the multiple current collectors 50. As a result, in the protruding region 91, a region is formed where there is no power generation layer 100 between adjacent current collectors 50. 【0110】 Furthermore, in the protruding region 91, the end faces 80 formed by the recession of each power generation layer 100 are aligned along the stacking direction (z-axis direction) of the power generation element 5. This makes it easier to form the protruding region 91. 【0111】 In the continuous region 92, for example, when viewed from the z-axis direction, the end faces 80a of each of the multiple power generation layers 100, specifically the end faces of the electrode layer 110, solid electrolyte layer 130, and counter electrode layer 120 of each of the multiple power generation layers 100, coincide with the end faces of each of the multiple current collectors 50. Therefore, in the continuous region 92, power generation layers 100 exist between adjacent current collectors 50. In the continuous region 92, for example, the end faces 80a of each of the multiple power generation layers 100 and the end faces of each of the multiple current collectors 50 form a continuous, flat surface perpendicular to the main surface of the multiple power generation layers 100, and are flush. Note that forming a flat surface means that it is substantially a flat surface, and for example, fine irregularities caused by cutting of the laminate formed by stacking the multiple power generation layers 100 and the multiple current collectors 50 may exist on the flat surface. 【0112】 Furthermore, the continuous region 92 is, for example, a region that includes the end portion of the side portion 11 in a direction perpendicular to the stacking direction of the power generation elements 5. As a result, the power generation layer 100 is positioned on adjacent current collectors 50 at the ridge portions of the power generation elements 5, suppressing contact between the current collectors 50 at the ridge portions of the power generation elements 5 where the influence of external forces is large. In addition, since the power generation layer 100 is positioned up to the same position as the end face of the current collector 50 in the continuous region 92, the volume of the power generation layer 100 can be increased compared to when the entire side portion 11 is the protruding region 91, while ensuring connection between the current collector 50 and the terminals in the protruding region 91, thereby further increasing the volumetric energy density of the battery 1. 【0113】 The side portion 12 also has a protruding region 91 and a continuous region 92, similar to the side portion 11. The side portions 13 and 14, for example, do not include a protruding region 91 and consist only of a continuous region 92, but are not limited to this and may include both a protruding region 91 and a continuous region 92. Furthermore, the structures of the side portions 11 and 12 are not limited to being formed on side portions 11 and 12 that are in opposite positions. For example, instead of side portions 11 and 12, the structures of side portions 11 and 12 may be formed on two adjacent (orthogonal) side portions, such as side portion 11 and side portion 13. 【0114】 Note that the side portions 11 and 12 do not necessarily have a continuous region 92. Also, in the side portions 11 and 12, the protruding region 91 may be separated into multiple parts by the continuous region 92. Figure 7 is another plan view of the power generation element 5 of the battery 1 according to this embodiment, viewed from the side. Figure 7 is a front view of the side portion 11, viewed from the front, similar to Figure 5. As shown in Figure 7, the protruding region 91 is separated into two parts by the continuous region 92 in the side portion 11. The protruding region 91 may be separated into three or more parts. Each of the separated protruding regions 91 is sandwiched on both sides by the continuous region 92 in a direction parallel to the main surfaces of the multiple power generation layers 100 in the side portion 11. As a result, the individual widths of the protruding parts 51 in the separated protruding regions 91 are reduced, making it more difficult for the protruding parts 51 to move. Therefore, short circuits caused by the protruding parts 51 moving and coming into contact with each other during the manufacturing process of the battery 1 are further suppressed. 【0115】 Next, the electrode insulating layer 21, the counter electrode insulating layer 22, the counter electrode terminal 31, and the electrode terminal 32 will be described in detail. 【0116】 The electrode insulating layer 21 is an example of an insulating member, and as shown in Figure 1, it covers the electrode layer 110 and the electrode current collector 61 on the side portion 11. Specifically, the electrode insulating layer 21 completely covers the electrode current collector 61 and the electrode layer 110 on the side portion 11. 【0117】 Figure 8 is a plan view showing the positional relationship between the side surface 11 of the power generation element 5 according to this embodiment and the electrode insulating layer 21 provided on the side surface 11. 【0118】 Figure 8 shows the side portion 11 shown in Figure 5 and the electrode insulating layer 21 provided on the side portion 11. In other words, Figure 8 is a plan view of the battery 1 in Figure 1 as seen from the positive side of the x-axis, with the counter electrode terminal 31 visible through it. 【0119】 As shown in Figures 1 and 8, the electrode insulating layer 21 covers each electrode layer 110 of the multiple power generation layers 100 on the side portion 11. The electrode insulating layer 21 also covers the electrode current collector 61 that is electrically connected to each electrode layer 110 of the multiple power generation layers 100 on the side portion 11. Furthermore, the electrode insulating layer 21 covers the protruding portion 51 of the electrode current collector 61 that is electrically connected to each electrode layer 110 of the multiple power generation layers 100. The main surface and end surface on both sides of the protruding portion 51 of the electrode current collector 61 are covered by the electrode insulating layer 21, and the protruding portion 51 of the electrode current collector 61 is completely embedded in the electrode insulating layer 21. This prevents the protruding portion 51 of the electrode current collector 61 from contacting the counter electrode current collector 62 and the counter electrode terminal 31, etc., and from discharging in close proximity to the counter electrode current collector 62 and the counter electrode terminal 31, etc. Therefore, the occurrence of a short circuit between the electrode layer 110 and the counter electrode layer 120 can be suppressed. 【0120】 Furthermore, the electrode insulating layer 21 does not cover at least a portion of each of the counter electrode layers 120 of the multiple power generation layers 100 on the side portion 11. The electrode insulating layer 21 does not cover the multiple counter electrode current collectors 62 on the side portion 11. In the example shown in Figure 8, the electrode insulating layer 21 does not cover at least a portion of each of the counter electrode layers 120 of the multiple power generation layers 100 and the multiple counter electrode current collectors 62 over the entire area of ​​the side portion 11, from the protruding region 91 to the continuous region 92. As a result, the electrode insulating layer 21 has a stripe shape when the side portion 11 is viewed from the front. 【0121】 In this configuration, the electrode insulating layer 21 continuously covers the electrode layers 110 of two adjacent power generation layers 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 power generation layers 100, and at least a portion of the solid electrolyte layer 130 of the other adjacent power generation layer 100. The electrode insulating layer 21 covers, for example, the electrode layer 110, the solid electrolyte layer 130, and the electrode current collector 61 by contact. 【0122】 Thus, the electrode insulating layer 21 covers at least a portion of the solid electrolyte layer 130 on the side portion 11. Specifically, when the side portion 11 is viewed from the front, 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. 【0123】 In this embodiment, the electrode insulating layer 21 may cover the entire solid electrolyte layer 130 on the side portion 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 layer 120. 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 layer 110. Furthermore, the electrode insulating layer 21 may cover not only the electrode layer 110, but also the entire solid electrolyte layer 130 and at least a portion of the counter electrode layer 120 on the side portion 11. 【0124】 As shown in Figure 1, the counter electrode insulating layer 22 covers the counter electrode layer 120 on the side portion 12. Specifically, the counter electrode insulating layer 22 completely covers the counter electrode current collector 62 and the counter electrode layer 120 on the side portion 12. 【0125】 The counter electrode insulating layer 22 covers each of the counter electrode layers 120 of the multiple power generation layers 100 on the side portion 12. The counter electrode insulating layer 22 also covers the counter electrode current collector 62 that is electrically connected to each of the counter electrode layers 120 of the multiple power generation layers 100 on the side portion 12. Furthermore, the counter electrode insulating layer 22 covers the protruding portion 51 of the counter electrode current collector 62 that is electrically connected to each of the counter electrode layers 120 of the multiple power generation layers 100. The main and end faces on both sides of the protruding portion 51 of the counter electrode current collector 62 are covered by the counter electrode insulating layer 22, and the protruding portion 51 of the counter electrode current collector 62 is completely embedded in the counter electrode insulating layer 22. This prevents the protruding portion 51 of the counter electrode current collector 62 from coming into contact with the electrode current collector 61 and electrode terminals 32, etc., causing a short circuit, and prevents discharge in close proximity to the electrode current collector 61 and electrode terminals 32, etc. 【0126】 The counter electrode insulating layer 22 does not cover at least a portion of each electrode layer 110 of the multiple power generation layers 100 on the side portion 12. The counter electrode insulating layer 22 does not cover the electrode current collector 61 on the side portion 12. For example, the counter electrode insulating layer 22 does not cover at least a portion of each electrode layer 110 of the multiple power generation layers 100 and the multiple electrode current collectors 61 over the entire area of ​​the side portion 12. Therefore, when the side portion 12 is viewed from the front (specifically, in this embodiment, viewed from the negative side in the x-axis direction), the counter electrode insulating layer 22 has a stripe shape, similar to the electrode insulating layer 21 shown in Figure 8. 【0127】 In this configuration, the counter electrode insulating layer 22 continuously covers the counter electrode layers 120 of two adjacent power generation layers 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 power generation layers 100, and at least a portion of the solid electrolyte layer 130 of the other adjacent power generation layer 100. The counter electrode insulating layer 22 covers, for example, the counter electrode layer 120, the solid electrolyte layer 130, and the counter electrode current collector 62 by contact. 【0128】 Thus, the counter electrode insulating layer 22 covers at least a portion of the solid electrolyte layer 130 on the side portion 12. Specifically, when the side portion 12 is viewed from the front, 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 on the end face of the solid electrolyte layer 130, thereby improving insulation reliability. 【0129】 In this embodiment, the counter electrode insulating layer 22 may cover the entire solid electrolyte layer 130 on its side portion 12. Specifically, the contour of the counter electrode insulating layer 22 may overlap with the boundary between the solid electrolyte layer 130 and the electrode layer 110. 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 with the boundary between the solid electrolyte layer 130 and the counter electrode layer 120. Furthermore, the counter electrode insulating layer 22 may cover not only the counter electrode layer 120, but also the entire solid electrolyte layer 130 and at least a portion of the electrode layer 110 on its side portion 12. 【0130】 Furthermore, in the power generation element 5 according to this embodiment, the uppermost and lowermost parts are counter electrode current collectors 62. As shown in Figure 1, near the upper and lower ends of the side portion 12, the counter electrode insulating layer 22 covers a portion of the main surface (i.e., main surfaces 15 and 16) of the counter electrode current collector 62 located at the uppermost and lowermost parts. As a result, the counter electrode insulating layer 22 is resistant to external forces from the z-axis direction and detachment is suppressed. Also, even if the electrode terminals 32 wrap around to the main surfaces 15 and 16 of the power generation element 5, they can contact the counter electrode current collector 62 and prevent short circuits. In this way, the reliability of the battery 1 can be improved by having the counter electrode insulating layer 22 cover a portion of the main surfaces 15 and 16. 【0131】 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. 【0132】 As shown in Figure 1, the counter electrode terminal 31 is an example of a conductive member that covers the side portion 11 and the electrode insulating layer 21 and is electrically connected to the counter electrode layer 120 directly and via the counter electrode current collector 62. Specifically, the counter electrode terminal 31 covers the electrode insulating layer 21 and the portion of the side portion 11 that is not covered by the electrode insulating layer 21. 【0133】 Figure 9 is a plan view showing the positional relationship between the side portion 11 of the power generation element 5 according to this embodiment, the electrode insulating layer 21 provided on the side portion 11, and the counter electrode terminal 31. Figure 9 is a plan view of the battery 1 in Figure 1 when viewed from the positive side of the x-axis. 【0134】 As shown in Figure 8, the ends of the counter electrode current collector 62 and the counter electrode layer 120 are exposed in the portion of the side surface 11 that is not covered by the electrode insulating layer 21. Therefore, as shown in Figures 1 and 9, the counter electrode terminal 31 contacts the ends of the counter electrode current collector 62 and the counter electrode layer 120, and is electrically connected to the counter electrode layer 120. 【0135】 Specifically, the counter electrode terminal 31 is connected to the protrusion 51 of the counter electrode current collector 62. For example, the counter electrode terminal 31 covers both the main surfaces and end surfaces of the protrusion 51 of the counter electrode current collector 62. The protrusion 51 of the counter electrode current collector 62 is completely embedded in the counter electrode terminal 31. Alternatively, the counter electrode terminal 31 may be connected to only one of the main surfaces of the protrusion 51. 【0136】 Furthermore, the counter electrode terminal 31 is in contact with and covers the end face of the counter electrode layer 120 adjacent to the counter electrode current collector 62 at the end face 80 of the power generation layer 100. Since the counter electrode layer 120 is made of a powdery material, it has very fine irregularities, similar to the solid electrolyte layer 130. The counter electrode terminal 31 fits into the irregularities of the end face of the counter electrode layer 120, improving the connection strength of the counter electrode terminal 31 and enhancing the reliability of the electrical connection. In addition, the counter electrode terminal 31 is connected to the main surface of the protrusion 51 of the counter electrode current collector 62 and the end face of the counter electrode layer 120, so no gap is formed between the protrusion 51 and the end face of the counter electrode layer 120. Therefore, the protrusion 51 is stably held by the counter electrode terminal 31, suppressing the wobbling of the protrusion 51, which is prone to wobbling due to its large projected area, thereby improving the mechanical strength of the battery 1. Note that a gap may be formed between the protrusion 51 and the end face of the counter electrode layer 120. For example, the boundary between the protrusion 51 on the end face 80 and the counter electrode layer 120 may not contact the counter electrode terminal 31, and a gap may be formed on the boundary. Even in this case, the effect of stably holding the protrusion 51 can be obtained by the counter electrode terminal 31 contacting the end face of the counter electrode layer 120. 【0137】 The counter electrode terminal 31 is electrically connected to the counter electrode current collector 62, which is electrically connected to each of the counter electrode layers 120 of the multiple power generation layers 100. As a result, each counter electrode current collector 62 is at the same potential as the counter electrode terminal 31. Consequently, the counter electrode terminal 31 is electrically connected to each of the counter electrode layers 120 of the multiple power generation layers 100. In other words, the counter electrode terminal 31 functions to electrically connect each of the power generation layers 100 in parallel. 【0138】 As shown in Figures 1 and 9, the counter terminal 31 covers almost the entire side portion 11 from the lower end to the upper end. 【0139】 In the power generation element 5 according to this embodiment, the uppermost and lowermost parts are counter electrode current collectors 62. As shown in Figure 1, at the upper and lower ends of the side portion 11, the counter electrode terminal 31 covers a portion of the main surface of the counter electrode current collector 62 located at the uppermost and lowermost parts, i.e., the main surfaces 15 and 16 of the power generation element 5. As a result, the counter electrode terminal 31 is resistant to external forces from the z-axis direction, and detachment is suppressed. In addition, since the connection area between the counter electrode terminal 31 and the counter electrode current collector 62 is increased, the connection resistance between the counter electrode terminal 31 and the counter electrode current collector 62 is reduced, and the high-current characteristics can be improved. For example, rapid charging of the battery 1 becomes possible. Note that if the uppermost and lowermost parts are electrode current collectors 61, the counter electrode terminal 31 may cover the main surfaces 15 and 16 via an insulating layer covering the electrode current collector 61. 【0140】 Furthermore, as shown in Figure 9, the counter electrode terminal 31 may cover the counter electrode current collector 62 and the counter electrode layer 120 in the continuous region 92. 【0141】 As shown in Figure 1, the electrode terminal 32 is an example of a conductive member that covers the side portion 12 and the counter electrode insulating layer 22 and is electrically connected to the electrode layer 110 directly and via the electrode current collector 61. Specifically, the electrode terminal 32 covers the counter electrode insulating layer 22 and the portion of the side portion 12 that is not covered by the counter electrode insulating layer 22. 【0142】 In the portion of the side surface 12 not covered by the counter electrode insulating layer 22, the ends of the electrode current collector 61 and the electrode layer 110 are exposed. As a result, as shown in Figure 1, the electrode terminal 32 contacts the ends of the electrode current collector 61 and the electrode layer 110, and is electrically connected to the electrode layer 110. 【0143】 Specifically, the electrode terminal 32 is connected to the protrusion 51 of the electrode current collector 61. For example, the electrode terminal 32 covers both the main surfaces and end surfaces of the protrusion 51 of the electrode current collector 61. The protrusion 51 of the electrode current collector 61 is completely embedded in the electrode terminal 32. Alternatively, the electrode terminal 32 may be connected to only one of the main surfaces of the protrusion 51. 【0144】 Furthermore, the electrode terminal 32 covers the end face 80 of the power generation layer 100, in contact with the end face of the electrode layer 110 adjacent to the electrode current collector 61. Since the electrode layer 110 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 layer 110, improving the adhesion strength of the electrode terminal 32 and enhancing the reliability of the electrical connection. In addition, since the electrode terminal 32 is connected to the main surface of the protrusion 51 of the electrode current collector 61 and the end face of the electrode layer 110, no gap is formed between the protrusion 51 and the end face of the electrode layer 110. Therefore, the protrusion 51 is stably held by the electrode terminal 32, suppressing the wobbling of the protrusion 51, which is prone to wobbling due to its large projected area, thereby improving the mechanical strength of the battery 1. Note that a gap may be formed between the protrusion 51 and the end face of the electrode layer 110. For example, the boundary between the protrusion 51 on the end face 80 and the electrode layer 110 may not contact the electrode terminal 32, and a gap may be formed on the boundary. Even in this case, the effect of stably holding the protrusion 51 can be obtained by the electrode terminal 32 contacting the end face of the electrode layer 110. 【0145】 The electrode terminal 32 is electrically connected to the electrode current collector 61, which is electrically connected to each electrode layer 110 of the multiple power generation layers 100. As a result, each electrode current collector 61 is at the same potential as the electrode terminal 32. Consequently, the electrode terminal 32 is electrically connected to each electrode layer 110 of the multiple power generation layers 100. In other words, the electrode terminal 32 functions to electrically connect each power generation layer 100 in parallel. 【0146】 As shown in Figure 1, the electrode terminal 32 covers almost the entire side portion 12 from the lower end to the upper end. 【0147】 Furthermore, similar to the counter electrode terminal 31 described using Figure 9, the electrode terminal 32 may cover the electrode current collector 61 and the electrode layer 110 in the continuous region 92. 【0148】 The counter electrode terminal 31 and the electrode terminal 32 are formed using a conductive resin material or the like. The conductive resin material includes, for example, a resin and a conductive material composed of metal particles or the like that filled in the resin. Alternatively, the counter electrode terminal 31 and the electrode terminal 32 may be formed using a metal 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 be formed using different materials. 【0149】 Furthermore, external electrodes may be formed on the counter electrode terminal 31 and electrode terminal 32 by other methods such as plating, printing, or soldering. Forming external electrodes can improve, for example, the mountability of the battery 1. 【0150】 As described above, the battery 1 comprises a power generation element 5 having a structure in which a plurality of power generation layers 100 and a plurality of current collectors 50 are stacked, and a counter electrode terminal 31. At least one of the plurality of current collectors 50 includes a protruding portion 51 that protrudes from the end face 80 of the power generation layer 100 and a stacked portion 55 which is the region in which the power generation layers 100 are stacked, on its side surface 11. When the protruding portion 51 and the stacked portion 55 are projected onto the projection plane P1, the projected area 51s of the protruding portion 51 is larger than the projected area of ​​the stacked portion 55. The counter electrode terminal 31 is connected to the protruding portion 51 and, on its side surface 11, is in contact with the end face of the counter electrode layer 120 adjacent to the at least one current collector 50. 【0151】 As a result, the protrusion 51 protrudes beyond the end face 80 of the power generation layer 100, allowing the counter electrode terminal 31 for extracting current to be connected to the main surface of the protrusion 51. Therefore, compared to the case where the terminal is connected to the end face of the current collector 50, the contact area between the counter electrode terminal 31 and the current collector 50 can be increased, reducing the resistance at the connection point. This suppresses voltage drop and heat generation at the connection point, improving high-current characteristics. Furthermore, the increased contact area between the counter electrode terminal 31 and the current collector 50 enhances the mechanical connection strength between the counter electrode terminal 31 and the current collector 50, improving the reliability of the battery 1. Additionally, the contact of the counter electrode terminal 31 with the counter electrode layer 120 improves the reliability of the electrical connection of the battery 1, and the protrusion 51 is stably held by the counter electrode terminal 31, improving the mechanical strength of the battery 1. 【0152】 Furthermore, the projected area 51s of the protrusion 51 is larger than the projected area of ​​the stacked portion 55, resulting in a structure where the protrusion 51 extends further in the stacking direction than the stacked portion 55. Therefore, when the protrusion 51 is connected to the counter electrode terminal 31, the protrusion 51 can bite into the counter electrode terminal 31, strengthening the mechanical connection between the current collector 50 and the counter electrode terminal 31 through an anchoring effect. Also, when comparing cases where the height from the end face 80 of the power generation layer 100 to the tip of the protrusion 51 is the same, the area of ​​the main surface of the protrusion 51 is larger than when the projected area 51s of the protrusion 51 is the same as the projected area of ​​the stacked portion 55. As a result, the connection area when connecting the counter electrode terminal 31 to the main surface of the protrusion 51 can be increased. In other words, the connection area when connecting the counter electrode terminal 31 to the main surface of the protrusion 51 can be increased without increasing the overall size of the battery 1. Thus, a high-performance battery 1 with improved reliability, energy density, and high-current characteristics can be realized. 【0153】 Furthermore, in battery 1, the counter electrode terminal 31 and the electrode terminal 32 each serve the function of parallel connection of multiple power generation layers 100. As shown in Figure 1, the counter electrode terminal 31 and the electrode terminal 32 are formed to closely cover the electrode insulating layer 21 and the counter electrode insulating layer 22, as well as the side portions 11 and 12 of the power generation element 5. This reduces the height of the terminals on the side portions 11 and 12, thereby reducing their volume. In other words, compared to the case where terminals are formed by stretching and joining or crimping protruding current collectors, the volume of the terminals is reduced, which improves the energy density per unit volume of battery 1. 【0154】 [Differentiation] In the example shown in Figure 8 above, the electrode insulating layer 21 is provided separately for every two adjacent electrode layers 110 with the electrode current collector 61 in between, but 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 portion 11 in the y-axis direction. Figure 10 is a plan view showing the positional relationship between the side portion 11 of the power generation element 5 according to a modified example of Embodiment 1 and the electrode insulating layer 21 provided on the side portion 11. Figure 10 shows the side portion 11 and the electrode insulating layer 21 provided on the side portion 11 as shown in Figure 5. Figure 11 is a plan view of the battery 1a according to a modified example of Embodiment 1 when viewed from the side (positive x-axis direction). Figure 10 is a plan view of the battery 1a in Figure 11 when viewed from the positive x-axis direction with the counter electrode terminal 31 visible through it. The battery 1a shown in Figure 11 has the same power generation element 5 as battery 1, but the shape of the electrode insulating layer 21 and the counter electrode terminal 31 are different from battery 1. 【0155】 As shown in Figure 10, in this modified example, the electrode insulating layer 21 covers all of the continuous regions 92 located on both sides of the protruding region 91 on the side portion 11. In other words, the shape of the electrode insulating layer 21 in this modified example is ladder-shaped when the side portion 11 is viewed from the front. Thus, the electrode insulating layer 21 may cover a part of the counter electrode current collector 62. Note that the electrode insulating layer 21 does not have to cover a part of the continuous region 92. 【0156】 Furthermore, in this modified example, the electrode insulating layer 21 is provided along the z-axis direction in a part of the protruding region 91 on the side surface 11. In other words, the electrode insulating layer 21 covers a part of the counter electrode current collector 62 even in the protruding region 91 on the side surface 11. 【0157】 As shown in Figure 11, in this modified example, the counter electrode terminal 31 covers both the electrode insulating layer 21 and the entire portion of the side surface 11 that is not covered by the electrode insulating layer 21. In other words, in battery 1a, the entire side surface 11 is covered by at least one of the electrode insulating layer 21 and the counter electrode terminal 31, and is not exposed. 【0158】 Thus, in the battery 1a, in the continuous region 92 where the counter electrode current collector 62 can only form an electrical connection at its end face, the counter electrode layer 120 and the counter electrode current collector 62 are covered by the electrode insulating layer 21. This suppresses a decrease in high-current characteristics while also suppressing collapse and short circuits of the power generation layer 100 in the continuous region 92, thereby improving reliability. 【0159】 Although not shown in the figures, the counter electrode insulating layer 22 may also be provided along the z-axis direction at the end of the side portion 12 in the y-axis direction, similar to the electrode insulating layer 21 on the side portion 11. In other words, the shape of the counter electrode insulating layer 22 may be ladder-shaped when the side portion 12 is viewed from the front. 【0160】 (Embodiment 2) Next, Embodiment 2 will be described. In the following, the differences from Embodiment 1 will be the main focus of the explanation, and the similarities will be omitted or simplified. 【0161】 Figure 12 is a cross-sectional view of the battery 201 according to Embodiment 2. As shown in Figure 12, the battery 201 according to Embodiment 1 differs from the battery 1 according to Embodiment 1 in that, of the electrode current collector 61 and the counter electrode current collector 62, only the counter electrode current collector 62 protrudes from the side portion 11, and only the electrode current collector 61 protrudes from the side portion 12. 【0162】 In the battery 201, on the side portion 11, each counter electrode current collector 62 protrudes beyond the end face 80 of the power generation layer 100, while each electrode current collector 61 does not protrude beyond the end face 80 of the power generation layer 100. In other words, each counter electrode current collector 62 includes a protruding portion 51 that extends beyond the end face 80 on the side portion 11. Also, each electrode current collector 61 does not include a protruding portion that extends beyond the end face 80 on the side portion 11. For example, when viewed from the z-axis direction on the side portion 11, the end face of the electrode current collector 61 coincides with the end face 80 of the power generation layer 100 adjacent to the electrode current collector 61. In this way, on the side portion 11, the electrode current collector 61 that is not connected to the counter electrode terminal 31 does not protrude, thus preventing contact and short circuits between the electrode current collector 61 and the counter electrode current collector 62 during the manufacturing process, etc. 【0163】 In the battery 201, on the side portion 12, each electrode current collector 61 protrudes beyond the end face 80 of the power generation layer 100, while each counter electrode current collector 62 does not protrude beyond the end face 80 of the power generation layer 100. In other words, each electrode current collector 61 includes a protruding portion 51 that extends beyond the end face 80 on the side portion 12. On the other hand, each counter electrode current collector 62 does not include a protruding portion that extends beyond the end face 80 on the side portion 12. For example, when viewed from the z-axis direction on the side portion 12, the end face of the counter electrode current collector 62 coincides with the end face 80 of the power generation layer 100 adjacent to the counter electrode current collector 62. In this way, since the counter electrode current collector 62, which is not connected to the electrode terminals 32, does not protrude on the side portion 12, contact between the electrode current collector 61 and the counter electrode current collector 62 and short-circuiting during the manufacturing process, etc., is suppressed. 【0164】 The electrode insulating layer 21 covers the electrode current collector 61 and the electrode layer 110 on the side portion 11 and is in contact with the electrode current collector 61 and the electrode layer 110. Specifically, the electrode insulating layer 21 continuously covers the end face of the electrode current collector 61 and the end face of the electrode layer 110 adjacent to the electrode current collector 61 on the side portion 11. In the battery 201, the end face of the electrode current collector 61 and the end face 80 of the power generation layer 100 are aligned and flush, so the electrode insulating layer 21 can be easily formed. In addition, since the electrode current collector 61 does not protrude from the electrode insulating layer 21, contact between the electrode current collector 61 and the counter electrode terminal 31 and short-circuiting are suppressed. 【0165】 The counter electrode insulating layer 22 covers the counter electrode current collector 62 and the counter electrode layer 120 on the side portion 12 and is in contact with the counter electrode current collector 62 and the counter electrode layer 120. Specifically, the counter electrode insulating layer 22 continuously covers the end face of the counter electrode current collector 62 and the end face of the counter electrode layer 120 adjacent to the counter electrode current collector 62 on the side portion 12. In the battery 201, the end face of the counter electrode current collector 62 and the end face 80 of the power generation layer 100 are aligned and flush, so the counter electrode insulating layer 22 can be easily formed. In addition, since the counter electrode current collector 62 does not protrude from the counter electrode insulating layer 22, contact between the counter electrode current collector 62 and the electrode terminal 32 and short-circuiting are suppressed. 【0166】 (Embodiment 3) Next, Embodiment 3 will be described. In the following, the differences from Embodiments 1 and 2 will be the main focus of the explanation, and the common points will be omitted or simplified. 【0167】 Figure 13 is a cross-sectional view of a battery 301 according to Embodiment 3. As shown in Figure 13, the battery 301 according to this embodiment differs from the battery 201 according to Embodiment 2 in that each of the multiple power generation layers 100 has, instead of an end face 80, an end face 380a where the counter electrode layer 120 is set back from the electrode layer 110 and an end face 380b where the electrode layer 110 is set back from the counter electrode layer 120. 【0168】 In the battery 301, on the side portion 11, each power generation layer 100 has an end face 380a formed where the end face of the counter electrode layer 120 is recessed compared to the end face of the electrode layer 110. Also, on the side portion 11, only the counter electrode layer 120 and the solid electrolyte layer 130 of the power generation layer 100 are recessed compared to the counter electrode current collector 62. Each counter electrode current collector 62 includes a protruding portion 51 that protrudes from the end face 380a on the side portion 11. Specifically, on the side portion 11, the protruding portion 51 of each counter electrode current collector 62 protrudes from the end face of the counter electrode layer 120 on the end face 380a. In other words, the counter electrode current collector 62 includes a protruding portion 51 that protrudes from the end face 380a on the side portion 11. Also, at least a portion of the solid electrolyte layer 130 is recessed compared to the electrode layer 110 on the end face 380a. Specifically, the portion of the end face of the solid electrolyte layer 130 that is not covered by the electrode insulating layer 21 is inclined diagonally with respect to the z-axis direction. Note that at the end face 380a, the solid electrolyte layer 130 does not necessarily have to be recessed compared to the electrode layer 110. 【0169】 In the side portion 11, when viewed from the z-axis direction, the end face of the electrode current collector 61 coincides with the end face of the electrode layer 110 adjacent to the electrode current collector 61 on the end face 380a. Therefore, each electrode current collector 61 does not have any protrusions that extend beyond the end face 380a in the side portion 11. In this way, since the electrode current collector 61 does not protrude in the side portion 11, contact between the electrode current collector 61 and the counter electrode current collector 62 and short-circuiting during the manufacturing process, etc., is suppressed. 【0170】 Furthermore, for example, at the side portion 11, the entire electrode current collector 61 is sandwiched between the electrode layer 110, so the electrode current collector 61 is firmly held. As a result, it becomes easy to bend or curve only the counter electrode current collector 62 that is connected to the counter electrode terminal 31 among the multiple current collectors 50. Thus, when bending or curving the counter electrode current collector 62, deformation of the electrode current collector 61 and contact between the electrode current collector 61 and the counter electrode current collector 62 are suppressed. 【0171】 Furthermore, in the side portion 12, each power generation layer 100 has an end face 380b formed where the end face of the electrode layer 110 is recessed compared to the end face of the counter electrode layer 120. Also, in the side portion 12, only the electrode layer 110 and the solid electrolyte layer 130 of the power generation layer 100 are recessed compared to the electrode current collector 61. Each electrode current collector 61 includes a protruding portion 51 that protrudes from the end face 380b in the side portion 12. Specifically, in the side portion 12, the protruding portion 51 of each electrode current collector 61 protrudes from the end face of the electrode layer 110 on the end face 380b. In other words, the electrode current collector 61 includes a protruding portion 51 that protrudes from the end face 380b in the side portion 12. Also, at least a portion of the solid electrolyte layer 130 is recessed compared to the counter electrode layer 120 on the end face 380b. Specifically, the portion of the end face of the solid electrolyte layer 130 that is not covered by the counter electrode insulating layer 22 is inclined at an angle with respect to the z-axis direction. Note that at the end face 380b, the solid electrolyte layer 130 does not need to be recessed compared to the counter electrode layer 120. 【0172】 In the side portion 12, when viewed from the z-axis direction, the end face of the counter electrode current collector 62 coincides with the end face of the counter electrode layer 120 adjacent to the counter electrode current collector 62 on the end face 380b. Therefore, each counter electrode current collector 62 does not have any protrusions that extend beyond the end face 380b in the side portion 12. In this way, since the counter electrode current collector 62 does not protrude in the side portion 12, contact between the electrode current collector 61 and the counter electrode current collector 62 and short-circuiting during the manufacturing process, etc., is suppressed. 【0173】 Furthermore, for example, at the side portion 12, the entire counter electrode current collector 62 is sandwiched by the counter electrode layer 120, so the counter electrode current collector 62 is firmly held. As a result, it becomes easy to bend or curve only the electrode current collector 61 that is connected to the electrode terminal 32 among the multiple current collectors 50. Thus, when bending or curving the electrode current collector 61, deformation of the counter electrode current collector 62 and contact between the electrode current collector 61 and the counter electrode current collector 62 are suppressed. 【0174】 The electrode insulating layer 21 covers the electrode current collector 61 and the electrode layer 110 on the side surface 11 and is in contact with the electrode current collector 61 and the electrode layer 110. Specifically, on the side surface 11, the electrode insulating layer 21 continuously covers the end face of the electrode current collector 61 and the portion of the end face 380a of the power generation layer 100 adjacent to the electrode current collector 61 that is not recessed from the electrode current collector 61. 【0175】 The counter electrode insulating layer 22 covers the counter electrode current collector 62 and the counter electrode layer 120 on the side portion 12 and is in contact with the counter electrode current collector 62 and the counter electrode layer 120. Specifically, on the side portion 12, the counter electrode insulating layer 22 continuously covers the end face of the counter electrode current collector 62 and the portion of the end face 380b of the power generation layer 100 adjacent to the counter electrode current collector 62 that is not recessed from the counter electrode current collector 62. 【0176】 For example, after forming the electrode insulating layer 21 and the counter electrode insulating layer 22 on the side portion 11 and the side portion 12, respectively, the side portion 11 and the side portion 12 are processed in various ways to recede the electrode layer 110, the counter electrode layer 120, and the solid electrolyte layer 130 that are not covered by the electrode insulating layer 21 and the counter electrode insulating layer 22, causing the current collector 50 to protrude relatively. At this time, a portion of the electrode insulating layer 21 and the counter electrode insulating layer 22 is scraped away, slightly reducing the thickness of the electrode insulating layer 21 and the counter electrode insulating layer 22, and the electrode layer 110 and the counter electrode layer 120, which are made of powder material, recede faster than the current collector 50, causing the current collector 50 to protrude. Therefore, since the electrode insulating layer 21 and the counter electrode insulating layer 22 can be formed on the flat side portion 11 and the side portion 12 before the current collector 50 protrudes, the manufacturing process can be simplified. 【0177】 (Embodiment 4) Next, Embodiment 4 will be described. In the following, the differences from Embodiments 1 to 3 will be the main focus of the explanation, and the explanation of the common points will be omitted or simplified. 【0178】 Figure 14 is a cross-sectional view of a battery 401 according to Embodiment 4. Figure 15 is a cross-sectional view illustrating the detailed structure of the current collector 50 of the battery 401 according to this embodiment. Figure 15 is a diagram showing one power generation layer 100 and two adjacent current collectors 50 on either side of the power generation layer 100 from among the multiple power generation layers 100 and multiple current collectors 50 in the power generation element 5 of the battery 401. As shown in Figures 14 and 15, the battery 401 according to this embodiment differs from the battery 1 according to Embodiment 1 in that the current collector 50 includes a protrusion 451 which has a different shape from the protrusion 51. 【0179】 As shown in Figures 14 and 15, the current collector 50 includes a protruding portion 451 that protrudes from the end faces 80 of the multiple power generation layers 100 on the side portion 11, and a stacked portion 55 where the multiple power generation layers 100 are stacked. 【0180】 Furthermore, the current collector 50 also includes protruding portions 451 that protrude from the end faces 80 of the multiple power generation layers 100 in the side portion 12. In the following description, the protruding portion 451 in the side portion 11 will be described as a representative example, but the protruding portion 451 in the side portion 12 has the same configuration as, for example, the protruding portion 451 in the side portion 11 to which the same description applies. 【0181】 Specifically, the protrusion 451 protrudes beyond the end face of the electrode layer 110 or the counter electrode layer 120 at the end face 80 of the power generation layer 100 adjacent to the current collector 50. The protrusion 451 is, for example, a region of the current collector 50 that, when viewed along the stacking direction, is outside the end face of the electrode layer 110 or the counter electrode layer 120 at the end face 80 of the power generation layer 100 adjacent to the current collector 50. 【0182】 The protruding portion 451 has an anchor portion 452 which is a part that is thicker than the laminated portion 55. The anchor portion 452 protrudes from the laminated portion 55 in a direction perpendicular to the main surface of the power generation layer 100. In addition, the anchor portion 452 protrudes in a stepped manner from the main surface of the protruding portion 451 along the lamination direction. When the side portion 11 or 12 is viewed from the outside in a direction parallel to the main surface of the power generation layer 100, the anchor portion 452 includes a part of the protruding portion 451 that does not overlap with the laminated portion 55. The anchor portion 452 is formed by increasing the thickness of a part of the protruding portion 451. It should be noted that the anchor portion 452 is not a part whose thickness is increased due to the surface roughness of the material of the current collector 50, but rather a part in which the current collector 50 has been intentionally treated to increase its thickness, resulting in a thickness greater than that of the laminated portion 55. 【0183】 The protruding portion 451 has an anchor portion 452 at its tip. The anchor portion 452 in the protruding portion 451 is formed, for example, by bending the tip of the protruding portion 451 once or more in the direction along the lamination direction, or by welding a metal piece thicker than the lamination portion 55 to the tip of the protruding portion 451. 【0184】 Note that the location and number of thicker portions in the protrusion 451 are not limited to this example. For example, the current collector 50 may include a protrusion 451a having an anchor portion 452a located inside the tip of the protrusion 451a, which is thicker than the laminated portion 55, as shown in Figures 14 and 15. In the protrusion 451a, for example, by applying a large pressure across the tip of the protrusion 451a, a portion thicker than the laminated portion 55 is formed slightly inside the tip. Also, the current collector 50 may have protrusions having two or more portions thicker than the laminated portion 55. 【0185】 Furthermore, when projecting the protruding portion 451 and the stacked portion 55 onto the projection surface P1 using the projection direction (white arrow in the figure) and projection surface P1 described in Embodiment 1, the projected area of ​​the protruding portion 451 is larger than the projected area of ​​the stacked portion 55. In detail, since the protruding portion 451 has an anchor portion 452 that extends beyond the stacked portion 55, the projected area of ​​the protruding portion 451 is larger than the projected area of ​​the stacked portion 55 by the amount of the area onto which the anchor portion 452 is projected. 【0186】 Thus, because the projected area of ​​the protrusion 451 is larger than the projected area of ​​the laminated portion 55, the mechanical connection between the current collector 50 and the terminal can be strengthened by the anchoring effect, similar to the battery 1, and the connection area between the protrusion 451 and the terminal can be increased without increasing the overall size of the battery 401. In addition, having a portion of the protrusion 451 that is thicker reduces the electrical resistance of the protrusion 451 itself. Therefore, the high-current characteristics can be improved. 【0187】 The maximum thickness of the anchor portion 452 in the protruding portion 451 is, for example, 1.5 times or more the thickness of the laminated portion 55. This effectively increases the mechanical connection strength and connection area between the current collector 50 and the terminal. Furthermore, the maximum thickness of the anchor portion 452 in the protruding portion 451 is, for example, less than the thickness of the power generation layer 100. 【0188】 In addition, batteries 201 and 301, as well as batteries 701 and 801 described later, which include a current collector 50 with a protruding portion 51, may also have a current collector 50 with a protruding portion 451 instead of the protruding portion 51. 【0189】 (Embodiment 5) Next, Embodiment 5 will be described. In the following, the differences from Embodiments 1 to 4 will be the main focus of the explanation, and the common points will be omitted or simplified. 【0190】 Figure 16 is a cross-sectional view of a battery 501 according to Embodiment 5. Figure 17 is a cross-sectional view illustrating the detailed structure of the current collector 50 of the battery 501 according to this embodiment. Figure 17 is a diagram showing one power generation layer 100 and two adjacent current collectors 50 on either side of the power generation layer 100 from among the multiple power generation layers 100 and multiple current collectors 50 in the power generation element 5 of the battery 501. As shown in Figures 16 and 17, the battery 501 according to this embodiment differs from the battery 1 according to Embodiment 1 in that the current collector 50 includes a protrusion 551 which has a different shape from the protrusion 51. 【0191】 As shown in Figures 16 and 17, the current collector 50 includes a protruding portion 551 that extends from the end faces 80 of the multiple power generation layers 100 on the side portion 11, and a stacked portion 55 where the multiple power generation layers 100 are stacked. 【0192】 Furthermore, the current collector 50 also includes protruding portions 551 that protrude from the end faces 80 of the multiple power generation layers 100 in the side portion 12. In the following description, the protruding portion 551 in the side portion 11 will be described as a representative example, but the protruding portion 551 in the side portion 12 has the same configuration as, for example, the protruding portion 551 in the side portion 11 to which the same description applies. 【0193】 Specifically, the protrusion 551 protrudes beyond the end face of the electrode layer 110 or the counter electrode layer 120 at the end face 80 of the power generation layer 100 adjacent to the current collector 50. The protrusion 551 is, for example, a region of the current collector 50 that, when viewed along the stacking direction, is outside the end face of the electrode layer 110 or the counter electrode layer 120 at the end face 80 of the power generation layer 100 adjacent to the current collector 50. 【0194】 The protruding portion 551 has an anchor portion 552 which is a part that is thicker than the laminated portion 55. The anchor portion 552 protrudes from the laminated portion 55 in a direction perpendicular to the main surface of the power generation layer 100. When the side portion 11 or 12 is viewed from the outside along a direction parallel to the main surface of the power generation layer 100, the anchor portion 552 includes a portion of the protruding portion 551 that does not overlap with the laminated portion 55. The anchor portion 552 is formed by the thickness of the protruding portion 551 increasing as it proceeds toward the tip of the protruding portion 551. 【0195】 Furthermore, when projecting the protruding portion 551 and the stacked portion 55 onto the projection surface P1 using the projection direction (white arrow in the figure) and projection surface P1 described in Embodiment 1, the projected area of ​​the protruding portion 551 is larger than the projected area of ​​the stacked portion 55. In detail, since the protruding portion 551 has an anchor portion 552 that extends beyond the stacked portion 55, the projected area of ​​the protruding portion 551 is larger than the projected area of ​​the stacked portion 55 by the amount of the area onto which the anchor portion 552 is projected. 【0196】 Thus, because the projected area of ​​the protrusion 551 is larger than the projected area of ​​the laminated portion 55, the mechanical connection between the current collector 50 and the terminal can be strengthened by the anchoring effect, similar to the battery 1, and the connection area between the protrusion 551 and the terminal can be increased without increasing the overall size of the battery 501. In addition, having a portion of the protrusion 551 that is thicker reduces the electrical resistance of the protrusion 551 itself. Therefore, the high-current characteristics can be improved. 【0197】 The maximum thickness of the anchor portion 552 in the protruding portion 551 is, for example, 1.5 times or more the thickness of the laminated portion 55. This effectively increases the mechanical connection strength and connection area between the current collector 50 and the terminal. Furthermore, the maximum thickness of the anchor portion 552 in the protruding portion 551 is, for example, less than the thickness of the power generation layer 100. 【0198】 In addition, batteries 201 and 301, as well as batteries 701 and 801 described later, which include a current collector 50 with a protruding portion 51, may also have a current collector 50 with a protruding portion 551 instead of the protruding portion 51. 【0199】 (Embodiment 6) Next, Embodiment 6 will be described. In the following, the differences from Embodiments 1 to 5 will be the main focus of the explanation, and the common points will be omitted or simplified. 【0200】 Figure 18 is a cross-sectional view of a battery 601 according to Embodiment 6. Figure 19 is a cross-sectional view illustrating the detailed structure of the current collector 650 of the battery 601 according to this embodiment. Figure 19 is a diagram showing one power generation layer 100 and two adjacent current collectors 650 on either side of the power generation layer 100 from among the multiple power generation layers 100 and multiple current collectors 650 in the power generation element 605 of the battery 601. As shown in Figures 18 and 19, the battery 601 according to this embodiment differs from the battery 1 according to Embodiment 1 in that it has a power generation element 605 in which, instead of a power generation element 5, some of the multiple current collectors 50 in the power generation element 5 are replaced with current collectors 650. 【0201】 The power generation element 605 has multiple power generation layers 100 and multiple current collectors 50 and 650. In the power generation element 605, two adjacent power generation layers 100 are stacked via one of the multiple current collectors 650. In addition, current collectors 50 are positioned at the top and bottom of the power generation element 605. In other words, the power generation element 605 has a configuration in which the current collectors 50 other than the top and bottom current collectors 50 in the power generation element 5 are replaced by current collectors 650. 【0202】 The current collector 650 has a multilayer structure in which two current collector layers 50a are stacked. The two current collector layers 50a are stacked directly or via an intermediate layer (not shown) and are at the same potential. The current collector layers 50a are made of the same material as the current collector 50 described above. The intermediate layer is, for example, conductive, but may also be insulating. The intermediate layer is made of, for example, a conductive resin material. 【0203】 The current collector 650 includes a protruding portion 651 that extends beyond the end faces 80 of the multiple power generation layers 100 on the side portion 11, and a stacked portion 655 where the multiple power generation layers 100 are stacked. The current collector 650 also includes a protruding portion 651 that extends beyond the end faces 80 of the multiple power generation layers 100 on the side portion 12. In the following description, the protruding portion 651 on the side portion 11 will be described as a representative example, but the protruding portion 651 on the side portion 12 has the same configuration to which the same description applies as, for example, the protruding portion 651 on the side portion 11. 【0204】 Specifically, the protrusion 651 protrudes beyond the end face of the electrode layer 110 or the counter electrode layer 120 at the end face 80 of the power generation layer 100 adjacent to the current collector 650. The protrusion 651 is the region of the current collector 650 that, when viewed along the stacking direction, is outside the end face of the electrode layer 110 or the counter electrode layer 120 at the end face 80 of the power generation layer 100 adjacent to the current collector 650. 【0205】 The protrusion 651 is branched. Specifically, the protrusion 651 is branched by the bending and separation of the ends of the two stacked current collector layers 50a so that they separate from each other. If the current collector layers 50a are stacked with an intermediate layer in between, the intermediate layer may be present on the surface of the separated current collector layers 50a. 【0206】 The protruding portion 651 has an anchor portion 652 that extends beyond the laminated portion 655 in a direction perpendicular to the main surface of the power generation layer 100. The anchor portion 652 includes a portion of the protruding portion 651 that does not overlap with the laminated portion 655 when viewed from the outside along the side portion 11 or 12 in a direction parallel to the main surface of the power generation layer 100. The anchor portion 652 is formed by the branching of the protruding portion 651. 【0207】 The protrusion 651 branches at one point inward from its center. Note that the number and location of branching points on the protrusion 651 are not limited to this example. 【0208】 The laminated portion 655 is located on the end face 80 side of the protruding portion 651 of the current collector 650, is connected to the protruding portion 651, and is an area that overlaps with the electrode layer 110 or counter electrode layer 120 of the power generation layer 100 adjacent to the current collector 650. The boundary between the protruding portion 651 and the laminated portion 655 is the position of the end face of the electrode layer 110 or counter electrode layer 120 of the power generation layer 100 adjacent to the current collector 650, when viewed along the lamination direction. 【0209】 Furthermore, when projecting the protruding portion 651 and the stacked portion 655 onto the projection surface P1 using the projection direction (white arrow in the figure) and projection surface P1 described in Embodiment 1, the projected area of ​​the protruding portion 651 is larger than the projected area of ​​the stacked portion 655. In detail, since the protruding portion 651 has an anchor portion 652 that extends beyond the stacked portion 655, the projected area of ​​the protruding portion 651 is larger than the projected area of ​​the stacked portion 655 by the amount of the area onto which the anchor portion 652 is projected. 【0210】 Thus, because the projected area of ​​the protrusion 651 is larger than the projected area of ​​the stacked portion 655, the mechanical connection between the current collector 650 and the terminal can be strengthened by the anchoring effect, similar to the battery 1, and the connection area between the protrusion 651 and the terminal can be increased without increasing the overall size of the battery 601. 【0211】 Furthermore, because the protrusion 651 is branched, the connection area between the current collector 650 and the terminal can be effectively increased compared to the case where the current collector without a laminated structure is bent. Specifically, the protrusion 651 is exposed when the power generation element 605 is alone, and the entire exposed protrusion 651 is covered by the counter electrode terminal 31 or electrode terminal 32. In addition to the main surfaces on both sides corresponding to the upper and lower surfaces when the two current collector layers 50a are not separated, the protrusion 651 is also connected to the counter electrode terminal 31 or electrode terminal 32 on the surface formed when the two current collector layers 50a are separated. Therefore, the connection area between the current collector 650 and the terminal is increased. 【0212】 Furthermore, the protruding portion 651 is not limited to a structure in which it branches due to the separation of two current-collecting layers 50a. For example, the current collector 650 may be composed of a single current-collecting layer 50a, and the protruding portion 651 may branch due to the bonding of a metal foil or the like to the main surface of the current-collecting layer 50a. 【0213】 Furthermore, batteries equipped with a current collector 50 including a protruding portion 51, such as the batteries 201 and 301 described above, and batteries 701 and 801 described later, may also be equipped with a current collector 650 instead of the current collector 50. 【0214】 (Embodiment 7) Next, Embodiment 7 will be described. In the following, the differences from Embodiments 1 to 6 will be the main focus of the explanation, and the common points will be omitted or simplified. 【0215】 Figure 20 is a cross-sectional view of the battery 701 according to Embodiment 7. As shown in Figure 20, the battery 701 according to this modified example differs from the battery 1 according to Embodiment 1 in that it further comprises a sealing member 700. 【0216】 The sealing member 700 exposes at least a portion of each of the counter electrode terminal 31 and the electrode terminal 32, and seals the power generation element 5. The sealing member 700 is provided, for example, so that the power generation element 5 is not exposed. 【0217】 The sealing member 700 is formed using, for example, an electrically insulating insulating material. As the insulating material, a generally known material for sealing members of batteries, such as a encapsulant, 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. 【0218】 The sealing member 700 may include multiple different insulating materials. For example, the sealing member 700 may have a multilayer structure. Each layer of the multilayer structure may be formed using a different material and have different properties. 【0219】 The sealing member 700 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 700 may be formed using a resin material in which multiple particles made of metal oxide material are dispersed. 【0220】 The particle size of the metal oxide material is, for example, less than or equal to the spacing between the current collectors 50. The particle shape of the metal oxide material is, for example, spherical, ellipsoidal, or rod-shaped, but is not limited to these. 【0221】 The provision of the sealing member 700 improves the reliability of the battery 701 in various aspects, including mechanical strength, short-circuit prevention, and moisture resistance. 【0222】 In the case of battery 701, the battery 1 according to Embodiment 1 further includes a sealing member 700, but other batteries such as the batteries according to Embodiments 2 to 6 described above and Embodiment 8 described later may also further include a sealing member 700. 【0223】 (Embodiment 8) Next, Embodiment 8 will be described. In the following, the differences from Embodiments 1 to 7 will be the main focus of the explanation, and the common points will be omitted or simplified. 【0224】 Figure 21 is a cross-sectional view of a battery 801 according to Embodiment 8. Figure 22 is a plan view showing the positional relationship between the side portion 811 of the power generation element 805 according to this embodiment, the insulating layer 28 provided on the side portion 811, and the connection terminal 38. Figure 22 is a plan view of the battery 801 of Figure 21 when viewed from the positive side of the x-axis. 【0225】 As shown in Figure 21, the battery 801 according to this embodiment differs from the battery 1 according to Embodiment 1 in that it includes a power generation element 805, an insulating layer 28, and a connection terminal 38 instead of a power generation element 5, an electrode insulating layer 21, and a counter electrode insulating layer 22, as well as a counter electrode terminal 31 and an electrode terminal 32. 【0226】 The power generation element 805, like the power generation element 5, has multiple power generation layers 100 and multiple current collectors 50. Also, in the power generation element 805, like the power generation element 5, two adjacent power generation layers 100 are stacked via one of the multiple current collectors 50. Furthermore, each of the multiple power generation layers 100 in the power generation element 5 is sandwiched between two adjacent current collectors 50. The power generation element 805 differs from the power generation element 5 in that the multiple power generation layers 100 are stacked so that they are electrically connected in series. In the power generation element 805, the multiple power generation layers 100 are stacked aligned along the z-axis so that the order of each layer constituting the power generation layer 100 is the same. As a result, the multiple power generation layers 100 are stacked so that they are electrically connected in series. 【0227】 Of the multiple current collectors 50, all current collectors 50 except for the uppermost and lowermost ones have an electrode layer 110 laminated and in contact with one main surface without an intervening solid electrolyte layer 130, and a counter electrode layer 120 laminated and in contact with the other main surface without an intervening solid electrolyte layer 130. In other words, of the multiple current collectors 50, all current collectors 50 except for the uppermost and lowermost ones are bipolar current collectors 68 in which one main surface is electrically connected to the electrode layer 110 and the other main surface is electrically connected to the counter electrode layer 120. Two adjacent power generation layers 100 are laminated via bipolar current collectors 68. In addition, in the power generation element 805, the uppermost current collector 50 is an electrode current collector 61, and the lowermost current collector 50 is a counter electrode current collector 62. 【0228】 The power generation element 805 includes four side surfaces at positions corresponding to the four side surfaces 11, 12, 13, and 14 of the power generation element 5, and two main surfaces at positions corresponding to the two main surfaces 15 and 16 of the power generation element 5. Specifically, as shown in Figure 21, the power generation element 805 includes a side surface 811 at a position corresponding to side surface 11, and a side surface 812 at a position corresponding to side surface 12. The power generation element 805 also includes a main surface 815 at a position corresponding to main surface 15, and a main surface 816 at a position corresponding to main surface 16. 【0229】 In the power generation element 805, each of the multiple current collectors 50 includes a protruding portion 51 or 51a that protrudes from the end face 80 of the power generation layer 100 on the side portion 811, and a laminated portion 55. The structure of the protruding portions 51 and 51a and the laminated portion 55 is the same as in Embodiment 1. 【0230】 Furthermore, in the power generation element 805, each of the multiple current collectors 50 does not include any protrusions that extend beyond the end face 80 of the power generation layer 100 on the side portion 812. Therefore, the side portion 812 is a flat surface where the positions of the multiple power generation layers 100 and the end faces of the multiple current collectors 50 are aligned when viewed from the z-axis direction. Note that even on the side portion 812, protrusions 51 may be formed on the current collectors 50. 【0231】 A connection terminal 38 is provided for each of the multiple current collectors 50 and is connected to the corresponding current collector 50. The connection terminal 38 is an example of a conductive member. Specifically, the connection terminal 38 covers the main surface and end surface of the projection 51 of the corresponding current collector 50 and is in contact with the main surface and end surface of the projection 51. In the illustrated example, the projection 51 of the current collector 50 is entirely embedded in the connection terminal 38. 【0232】 The connection terminal 38 may cover a portion of the end face 80 of the power generation layer 100 adjacent to the corresponding current collector 50. Specifically, the connection terminal 38 may be in contact with the end face of the electrode layer 110 or counter electrode layer 120 of the power generation layer 100 adjacent to the corresponding current collector 50. However, the connection terminal 38 is not in contact with the end face of the electrode layer 110 or counter electrode layer 120 that is laminated to the corresponding current collector 50 via the solid electrolyte layer 130. 【0233】 The connection terminal 38 can be made from the materials listed above as being used for the counter electrode terminal 31 and electrode terminal 32. Multiple connection terminals 38 are formed from the same material, but they may also be formed from different materials. Furthermore, external electrodes may be formed on the connection terminal 38 by other methods such as plating, printing, or soldering. Forming external electrodes can improve the mountability of the battery 801, for example. 【0234】 For example, the connection terminal 38 can be used to monitor the state of each power generation layer 100 by measuring the potential of the connection terminal 38, thereby preventing overcharging and over-discharging. Furthermore, if there are variations in the charge state among the power generation layers 100, the variations in the charge state can be reduced by using the connection terminal 38 for charging and discharging individual power generation layers 100. 【0235】 As shown in Figure 22, the side portion 811, like the battery 1, has a protruding region 91 and continuous regions 92 located on both sides of the protruding region 91. The multiple connection terminals 38 are arranged along the stacking direction in the protruding region 91 when the side portion 811 is viewed from the front. The multiple connection terminals 38 extend along a direction parallel to the main surfaces of the multiple power generation layers 100 when the side portion 811 is viewed from the front, and have a stripe shape. Note that the side portion 811 does not necessarily have continuous regions 92, and may be entirely composed of protruding regions 91. 【0236】 As shown in Figures 21 and 22, the insulating layer 28 covers the side portion 811 such that at least a portion of each of the multiple connection terminals 38 is exposed. The insulating layer 28 is an example of an insulating member. In this embodiment, the insulating layer 28 covers all of the area of ​​the side portion 811 that is not covered by the connection terminals 38. By covering the exposed portion of the side portion 811 of the power generation element 805 with the insulating layer 28, collapse and short circuits at the end faces of each layer can be suppressed. Note that the battery 801 does not necessarily have to be equipped with the insulating layer 28. 【0237】 Furthermore, the insulating layer 28 may continuously cover the main surface 815 to the main surface 816 of the power generation element 805. In this case, for example, a portion of the insulating layer 28 may be provided in contact with the main surface 815, and another portion may be provided in contact with the main surface 816. 【0238】 The insulating layer 28 can be made from the materials listed above as materials used for the electrode insulating layer 21 and the counter electrode insulating layer 22. 【0239】 Note that the arrangement of the multiple connection terminals 38 when the side portion 811 is viewed from the front is not limited to the example shown in Figure 22. For example, the multiple connection terminals 38 may be formed along the entire length of the end face of the current collector 50 when the side portion 811 is viewed from the front. Also, as shown in Figure 23, the multiple connection terminals 38 may be arranged along a direction inclined with respect to the stacking direction when the side portion 811 is viewed from the front. Figure 23 is a plan view of a modified example of Embodiment 8 of the battery 801a when viewed from the side (positive side in the x-axis direction). In the battery 801a, for example, when viewed along the stacking direction, the multiple connection terminals 38 do not overlap each other. This suppresses short circuits caused by contact between the multiple connection terminals 38. 【0240】 (Manufacturing method) Next, we will describe the manufacturing method of the battery according to each of the embodiments described above. Note that the manufacturing method described below is just one example, and the manufacturing method of the battery according to each of the embodiments described above is not limited to the following example. 【0241】 A battery manufacturing method according to each embodiment includes, for example, a first step of preparing a plurality of unit cells, a second step of forming a power generation element which is an example of a laminate, and a third step of forming a conductive member. 【0242】 [Manufacturing method example 1] First, we will describe Example 1 of a battery manufacturing method according to each embodiment. 【0243】 Figure 24 is a flowchart of Example 1 of a battery manufacturing method according to each embodiment. Example 1 of the manufacturing method is a method for manufacturing batteries 1, 401, 501, 601, 701 and 801, for example. The following description of Example 1 of the manufacturing method will focus on the manufacturing of battery 1. In Example 1 of the manufacturing method, step S11 corresponds to the first step, steps S12, S13 and S14 correspond to the second step, and step S16 corresponds to the third step. 【0244】 As shown in Figure 24, first, a plurality of unit cells are prepared, each having a structure in which a power generation layer and a current collection layer are stacked (step S11). Next, the plurality of unit cells are stacked to form a laminate (step S12). The power generation layer 100 includes, as described above, an electrode layer 110, a counter electrode layer 120 positioned opposite the electrode layer 110, and a solid electrolyte layer 130 located between the electrode layer 110 and the counter electrode layer 120. Figures 25A to 25C are cross-sectional views of an example of a unit cell, respectively. 【0245】 As shown in Figure 25A, a unit cell 100a has one power generation layer 100 and two current collector layers 50a. In the unit cell 100a, the power generation layer 100 is positioned between the two current collector layers 50a, and the power generation layer 100 is in contact with each of the two current collector layers 50a. Specifically, the electrode layer 110 of the power generation layer 100 is in contact with one of the two current collector layers 50a, and the counter electrode layer 120 of the power generation layer 100 is in contact with the other of the two current collector layers 50a. 【0246】 Furthermore, as shown in Figures 25B and 25C, unit cell 100b and unit cell 100c each have one power generation layer 100 and one current collection layer 50a. 【0247】 In unit cell 100b, the current collector layer 50a is positioned opposite the power generation layer 100 on the electrode layer 110 side of the power generation layer 100 and is in contact with the electrode layer 110. In unit cell 100b, the main surface of the counter electrode layer 120 of the power generation layer 100, on the side opposite to the solid electrolyte layer 130, is exposed. 【0248】 In unit cell 100c, the current collector layer 50a is positioned opposite the power generation layer 100 on the counter electrode layer 120 side of the power generation layer 100 and is in contact with the counter electrode layer 120. In unit cell 100c, the main surface of the electrode layer 110 of the power generation layer 100, on the side opposite to the solid electrolyte layer 130, is exposed. 【0249】 For example, in step S11, at least one of the above-mentioned unit cells 100a, 100b, and 100c is prepared in accordance with the stacked configuration of the power generation element of the battery to be manufactured. For example, one unit cell 100a, multiple unit cells 100b, and multiple unit cells 100c are prepared. Then, unit cell 100a is placed in the bottom layer, and unit cells 100b and unit cells 100c are stacked alternately upwards. At this time, the unit cells 100b are stacked upside down compared to the orientation shown in Figure 25B. This forms a stacked structure of a power generation element 5 having a stacked structure in which multiple power generation layers 100 and multiple current collectors 50, each consisting of a current collector layer 50a, are stacked. 【0250】 The method for forming the laminate having a laminated structure of power generation elements 5 is not limited to this. For example, a unit cell 100a may be placed in the uppermost layer. Alternatively, a unit cell 100a may be placed in a position different from both the uppermost and lowermost layers. Multiple unit cells 100a may also be used. Furthermore, by applying double-sided coating to a single current collector layer 50a, a unit cell unit in which the power generation layer 100 is laminated on both main surfaces of the current collector layer 50a may be formed, and the formed units may be laminated. In addition, a unit cell consisting only of the power generation layer 100 and without a current collector layer 50a may be used as the unit cell. 【0251】 Furthermore, when manufacturing a battery equipped with a power generation element 605, for example, multiple unit cells 100a are prepared and stacked while alternately reversing the orientation of each layer of the power generation layer 100. This forms a laminate having a stacked structure of a power generation element 605, in which multiple power generation layers 100 and multiple current collectors 650, each consisting of a multilayer structure of two current collection layers 50a, are stacked. In this case, the multiple unit cells 100a are stacked after, for example, a conductive resin material that will serve as an intermediate layer is applied to the main surface. This results in the multiple unit cells 100a being stacked via an intermediate layer. Note that the multiple unit cells 100a may be stacked via an insulating adhesive material that will serve as an intermediate layer, or they may be stacked directly. 【0252】 Furthermore, when manufacturing a battery equipped with a power generation element 805, one unit cell 100a, multiple unit cells 100b, or multiple unit cells 100c are prepared, and the multiple unit cells are stacked with each layer of the power generation layer 100 facing the same direction. This forms a laminate having a stacked structure of a power generation element 805, in which multiple power generation layers 100 and multiple current collectors 50, each consisting of a current collector layer 50a, are stacked. 【0253】 Next, the laminate formed in step S12 is cut (step S13). For example, by cutting the ends of a laminate of multiple unit cells together along the lamination direction, a power generation element 5, 605, or 805 can be formed with flat sides formed as the cut surface. For example, in the case of power generation element 5, a structure like that shown in Figure 6 is formed throughout. This makes it possible to equalize the area of ​​each layer without being affected by variations in the coating area of ​​each layer. As a result, variations in battery capacity are reduced, and the accuracy of battery capacity is improved. The cutting process can be carried out by mechanical cutting using a blade, ultrasonic cutting using an ultrasonic cutter, laser cutting, or jet cutting, for example. 【0254】 Step S13 may be omitted if the unit cell is already formed in a shape corresponding to the desired shape of the power generation element 5, 605, or 805. 【0255】 Next, a protrusion is formed on the current collector that extends beyond the end face of the power generation layer (step S14). At this time, when projecting the protrusion 51 and the laminated portion 55 from the outside of the side portion 11 along a direction parallel to the main surface of the power generation layer 100 with respect to a projection plane P1 perpendicular to the main surface of the power generation layer 100, the protrusion 51 is formed such that the projected area of ​​the protrusion 51 is larger than the projected area of ​​the laminated portion 55. 【0256】 For example, first, a recession process is performed on the side portions 11 and 12 of the power generation element 5 to recede the power generation layer 100 from the current collector 50, thereby causing the end of the current collector 50 to protrude beyond the end face 80 of the power generation layer 100. In the recession process, for example, the power generation layer 100 is receded from the current collector 50 by polishing, sandblasting, brushing, etching, laser irradiation, or plasma irradiation of each power generation layer 100. 【0257】 When the power generation layer 100 is recessed by polishing, sandblasting, or brushing, for example, the difference in processing speed between the current collector 50 and the power generation layer 100 is used to recess the power generation layer 100, which is easily worn away. 【0258】 Furthermore, when the power generation layer 100 is recessed by etching, for example, the etching is performed under conditions where the etching rate of the current collector 50 is smaller than the etching rate of each layer of the power generation layer 100, thereby recessing the power generation layer 100. For example, wet etching can be used for etching. 【0259】 Furthermore, when the power generation layer 100 is retracted by laser irradiation or plasma irradiation, for example, the irradiation process is performed under conditions where the processing speed of the current collector 50 is less than the processing speed of each layer of the power generation layer 100, thereby retracting the power generation layer 100. For example, oxygen plasma can be used for plasma irradiation. 【0260】 In the retraction process, for example, a protective member is provided in the area of ​​the side of the power generation element other than the area where the current collector 50 protrudes (for example, the continuous area 92 described above), and only the desired area is retracted. As a result, a power generation element 5 is obtained in which a protruding area 91 and a continuous area 92 are formed on the side portion 11 and the side portion 12. 【0261】 Next, the projection 51 of the current collector 50 that protrudes from the end face 80 of the power generation layer 100 is mechanically bent to enlarge its projection area, so that the projection area of ​​the projection 51 is larger than the projection area of ​​the stacked portion 55. As a result, an anchor portion 52 is formed on the projection 51 of at least one current collector 50 in the side portions 11 and 12 by bending. Mechanical bending can be performed by pressing a plate-shaped pressing member or the like against the end face of a unit cell, thereby bending the projection 51 of multiple current collectors 50 all at once. Alternatively, the projection 51 of multiple current collectors 50 may be bent individually by sandwiching and bending them. The projection 51 may also be bent by wind pressure, such as by blowing gas onto it. Furthermore, depending on the bending conditions, the current collector 50 may be bent so that an anchor portion 452 is formed at its tip, thereby forming the projection 451 in the battery 401. 【0262】 When manufacturing the battery 501, for example, in step S13, as an area expansion process, a portion of the edge of the power generation layer 100 is removed by cutting it all at once under conditions of high mechanical friction, such as using mechanical cutting or ultrasonic cutting, and the edge of the current collector 50 is pushed into the removed area. This forms an anchor portion 552 that increases in thickness towards the tip of the current collector 50, and in the subsequent step S14, a retraction process is performed to form a protruding portion 551. In other words, part of the process of forming the protruding portion 551 may be performed in parallel with step S13. 【0263】 Furthermore, the protrusions 51, 451, or 551 may be formed by forming the power generation element 5 using a unit cell having a current collector layer 50a that has been pre-processed to the shape of the anchor portion 52, 452, or 552, and then performing a recession process on the power generation layer 100. In other words, part of the process of forming the protrusions may be performed in parallel with step S11. 【0264】 Furthermore, when manufacturing the battery 601, for example, after performing a recession treatment of the power generation layer 100 on the power generation element 605, an area expansion treatment is performed to separate the ends of the two stacked current collector layers 50a to form a protruding portion 651. If the two current collector layers 50a are stacked with an intermediate layer in between, the two current collector layers 50a are separated by removing the intermediate layer, for example by dissolving the material with a solvent. Alternatively, the two current collector layers 50a may be separated by removing the intermediate layer at the separation point by heating, plasma irradiation, or laser irradiation. In addition, the recession treatment of the power generation layer 100 and the removal of the intermediate layer may be performed simultaneously using methods such as material dissolution, heating, plasma irradiation, or laser irradiation. 【0265】 Next, insulating material is formed on the side surface of the power generation element (step S15). Specifically, an electrode insulating layer 21 is formed on the side surface 11 of the power generation element 5, and a counter electrode insulating layer 22 is formed on the side surface 12 of the power generation element 5. 【0266】 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. 【0267】 Furthermore, when forming the electrode insulating layer 21 and the counter electrode insulating layer 22, a protective member may be formed in areas where insulating material should not be formed, such as by masking with tape or by resist treatment, so that the areas connected to the counter electrode terminal 31 and the electrode terminal 32 are not insulated. After the formation of the electrode insulating layer 21 and the counter electrode insulating layer 22, the conductivity of the connection points with the terminals can be ensured by removing the protective member. 【0268】 Next, a conductive member is formed on the side surface portion of the power generation element (step S16). Specifically, a counter electrode terminal 31 is formed on the side surface portion 11 of the power generation element 5, and an electrode terminal 32 is formed on the side surface portion 12 of the power generation element 5. Further, the counter electrode terminal 31 and the electrode terminal 32 are formed so as to be connected to the main surface of the protruding portion 51. Further, the counter electrode terminal 31 is formed so as to contact the end surface of the counter electrode layer 120 on the side surface portion 11, and the electrode terminal 32 is formed so as to contact the end surface of the electrode layer 110 on the side surface portion 12. 【0269】 For example, the counter electrode terminal 31 is formed by applying and curing a conductive resin so as to cover the electrode insulating layer 21 and the portion of the side surface portion 11 not covered by the electrode insulating layer 21. Thereby, the counter electrode terminal 31 is connected to the main surface of the protruding portion 51 of each counter electrode current collector 62 of the power generation element 5. Further, the electrode terminal 32 is formed by applying and curing a conductive resin so as to cover the counter electrode insulating layer 22 and the portion of the side surface portion 12 not covered by the counter electrode insulating layer 22. Thereby, the electrode terminal 32 is connected to the main surface of the protruding portion 51 of each electrode current collector 61 of the power generation element 5. Note that the counter electrode terminal 31 and the electrode terminal 32 may be formed by, for example, printing, plating, vapor deposition, sputtering, welding, soldering, bonding, or other methods. 【0270】 Through the above steps, the battery 1 shown in FIG. 1 can be manufactured. 【0271】 Note that a step of pressing the plurality of unit cells prepared in step S11 individually or after laminating the plurality of unit cells may be performed in the stacking direction. 【0272】 In addition, when manufacturing the battery 701, after forming the conductive member (step S16), a sealing member 700 shown in FIG. 20 may be formed (step S17). The sealing member 700 is formed, for example, by applying and curing a resin material having fluidity. The application is performed by an inkjet method, a spray method, a screen printing method, a gravure printing method, or the like. The curing is performed by drying, heating, light irradiation, or the like depending on the resin material used. 【0273】 [Manufacturing method example 2] Next, we will describe Example 2 of the battery manufacturing method according to each embodiment. In the following, we will focus on the differences from Manufacturing Method Example 1, and omit or simplify the explanation of the common points. 【0274】 Figure 26 is a flowchart showing an example 2 of a battery manufacturing method according to each embodiment. Manufacturing method example 2 is a manufacturing method for, for example, the production of a battery 201. In manufacturing method example 2, step S11 corresponds to the first step, steps S22 and S23 correspond to the second step, and step S16 corresponds to the third step. 【0275】 As shown in Figure 26, first, multiple unit cells are prepared, each having a structure in which a power generation layer and a current collection layer are stacked (step S11). 【0276】 Next, a protrusion is formed on the current collector that extends beyond the end face of the power generation layer (step S22). In step S22, a setback process is performed to set back the power generation layer 100 of the unit cell before stacking, so that the current collector 50, which consists of the current collection layer 50a, protrudes beyond the end face 80 of the power generation layer 100. In the setback process in step S22, in addition to the method described in step S14 of the above-mentioned manufacturing method example 1, the power generation layer 100 may be set back beyond the current collection layer 50a and the current collector 50 protrudes beyond the end face 80 of the power generation layer 100 by partially cutting the unit cell prepared in step S11, leaving only the current collection layer 50a of the unit cell in a predetermined area in a plan view, thereby setting back the power generation layer 100 beyond the current collection layer 50a. For example, the power generation layer 100 of the unit cell is cut and divided along the stacking direction, and the cutting is stopped before the current collection layer 50a. By removing one of the divided power generation layers 100, only the current collection layer 50a of the unit cell can be left in a predetermined area in a plan view. The current collector layer 50a in a predetermined region ultimately becomes the protruding portion 51 of the current collector 50. 【0277】 Next, a power generation element is formed by stacking multiple unit cells with protruding current collectors (step S23). For example, the protruding portions 51 are arranged such that only the counter electrode current collector 62 protrudes on the side portion 11, and only the electrode current collector 61 protrudes on the side portion 12, and multiple unit cells are stacked so that the positions of the power generation layer 100 are aligned when viewed along the stacking direction. After that, the power generation element 5 shown in Figure 12 is formed by mechanically bending the protruding portions 51 or performing other area expansion processing in the same manner as described above. In other words, part of the process of forming the protruding portions 51 may be performed in parallel with step S23. Note that the bending of the protruding portions 51 may be performed on the current collectors 50 of the unstacked unit cells before step S23. 【0278】 Next, insulating and conductive members are formed on the side surfaces of the power generation element (steps S15 and S16). Through these steps, the battery 201 shown in Figure 12 can be manufactured. Furthermore, a sealing member may be formed on the battery 201 if necessary (step S17). 【0279】 Furthermore, by applying manufacturing method example 2, batteries 1, 401, 501, 601, 701, and 801 can also be manufactured. In other words, in step S22, protrusions corresponding to the shapes of batteries 1, 401, 501, 601, 701, and 801 may be formed on the unit cells before stacking, and multiple unit cells with protrusions formed thereon may be stacked. 【0280】 [Manufacturing method example 3] Next, we will describe Example 3 of the battery manufacturing method according to each embodiment. In the following, we will focus on the differences from Manufacturing Method Example 1, and omit or simplify the explanation of the common points. 【0281】 Figure 27 is a flowchart of manufacturing method example 3 for each embodiment of a battery. Manufacturing method example 3 is a manufacturing method for, for example, manufacturing a battery 301. In manufacturing method example 3, step S11 corresponds to the first step, steps S12, S13, S34 and S35 correspond to the second step, and step S16 corresponds to the third step. 【0282】 As shown in Figure 27, first, multiple unit cells are prepared, each having a structure in which a power generation layer and a current collection layer are stacked (Step S11). Next, the multiple unit cells are stacked to form a laminate (Step S12). Then, the laminate is cut (Step S13). The steps up to this point are the same as in Manufacturing Method Example 1. 【0283】 Next, insulating material is formed on the side surface of the power generation element (step S34). Specifically, in the power generation element 5 before the protrusion 51 is formed on the current collector 50, an electrode insulating layer 21 is formed on the side surface 11 and a counter electrode insulating layer 22 is formed on the side surface 12. The same method as in step S15 described above can be used to form the electrode insulating layer 21 and the counter electrode insulating layer 22. 【0284】 Next, a protrusion is formed on the current collector that extends beyond the end face of the power generation layer (step S35). For example, first, at the side portions 11 and 12 of the power generation element 5, a recession process is performed to recede the power generation layer 100 behind the current collector 50. At this time, at the side portion 11, since the electrode layer 110 and the electrode current collector 61 are covered by the electrode insulating layer 21, the electrode insulating layer 21 functions as a protective member during the recession process. As a result, at the side portion 11, the counter electrode layer 120 and the solid electrolyte layer 130 of the power generation layer 100 recede to form an end face 380a, and a protrusion 51 is formed on the counter electrode current collector 62 that extends beyond the end face 380a. Also, at the side portion 12, since the counter electrode layer 120 and the counter electrode current collector 62 are covered by the counter electrode insulating layer 22, the counter electrode insulating layer 22 functions as a protective member during the recession process. As a result, at the side portion 12, the electrode layer 110 and the solid electrolyte layer 130 of the power generation layer 100 recede to form an end face 380b, and a protruding portion 51 is formed on the electrode current collector 61 that protrudes from the end face 380b. Subsequently, the protruding portion 51 is subjected to an area-enlarging process, such as mechanically bending it in the same manner as described above, to form the power generation element 5 shown in Figure 13. 【0285】 Further, if necessary, after performing the retreat process, the electrode insulating layer 21 and the counter electrode insulating layer 22 may be reformed. Thereby, even when a part of the electrode insulating layer 21 and the counter electrode insulating layer 22 is removed by the retreat process, the protection function of the power generation element 5 by the electrode insulating layer 21 and the counter electrode insulating layer 22 can be enhanced by the reformation. 【0286】 Next, a conductive member is formed on the side surface portion of the power generation element (step S16). Through the above steps, the battery 301 shown in FIG. 13 can be manufactured. Further, if necessary, a sealing member may be formed on the battery 301 (step S17). 【0287】 (Other embodiments) As described above, the battery and the method for manufacturing the battery according to one or more aspects have been described based on the embodiments. However, the present disclosure is not limited to these embodiments. As long as the gist of the present disclosure is not deviated, various modifications conceived by those skilled in the art applied to these embodiments, and forms constructed by combining components in different embodiments are also included in the scope of the present disclosure. 【0288】 For example, the connection relationship of the plurality of power generation layers 100 in the power generation element is not limited to the example described in the above embodiment. For example, all of the plurality of power generation layers 100 may be connected in parallel or in series, or may be combined in any combination of series connection and parallel connection. 【0289】 Also, various changes, replacements, additions, omissions, etc. can be made within the scope of the claims or their equivalents in each of the above embodiments. 【Industrial applicability】 【0290】 The battery according to the present disclosure can be used, for example, as a battery for electronic devices, electrical appliance devices, and electric vehicles. 【Explanation of reference numerals】 【0291】 1, 1a, 201, 301, 401, 501, 601, 701, 801, 801a batteries 5, 605, 805 power generation elements 11, 12, 13, 14, 811, 812 Side part 15, 16, 815, 816 Main surface 21 Electrode insulating layer 22 Counter electrode insulating layer 28 Insulating layer 31 Counter terminal 32 Electrode terminal 38 connection terminals 50, 650 current collector 50a current collector layer 51, 51a, 51b, 451, 451a, 551, 651 Protrusion 51s projected area 52, 452, 452a, 552, 652 Anchor section 55, 655 Laminated section 61 Electrode current collector 62 Counter electrode current collector 68 Bipolar current collector 80, 80a, 380a, 380b end face 91 Prominent area 92 continuous regions 100 power generation layers 100a, 100b, 100c unit cells 110 Electrode layer 120 Counterpolar layer 130 Solid electrolyte layer 700 Sealing member P1 projection plane

Claims

[Claim 1] A power generation element having a structure in which multiple power generation layers and multiple current collectors are stacked, A conductive member is provided, Each of the plurality of power generation layers has an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, and is sandwiched between two adjacent current collectors among the plurality of current collectors. Two adjacent power generation layers among the plurality of power generation layers are stacked via one of the plurality of current collectors. The aforementioned plurality of current collectors are not in contact with each other. At least one of the plurality of current collectors includes a protruding portion that extends from the end face of the plurality of power generation layers on the side surface of the power generation element, and a laminated portion located on the end face side of the protruding portion and connected to the protruding portion, which is a portion where the plurality of power generation layers are laminated. When projecting the protruding portion and the stacked portion from the outside of the side portion along a direction parallel to the main surface of the multiple power generation layers onto a projection plane perpendicular to the main surface of the multiple power generation layers, the projected area of ​​the protruding portion is larger than the projected area of ​​the stacked portion. The conductive member is connected to the main surface of the protruding portion, The conductive member, on its side surface, is in contact with the end face of the electrode layer or counter electrode layer adjacent to the at least one current collector. battery. [Claim 2] The aforementioned protrusion is bent or curved. The battery according to claim 1. [Claim 3] The maximum angle of bending or curvature in the protruding portion is 90 degrees or less with respect to the laminated portion. The battery according to claim 2. [Claim 4] The maximum angle of bending or curvature at the protruding portion is 1 degree or more and 45 degrees or less with respect to the laminated portion. The battery according to claim 2. [Claim 5] The protruding portion has a portion that is thicker than the laminated portion. The battery according to claim 1. [Claim 6] The maximum thickness of the portion with the greater thickness in the protruding portion is 1.5 times or more the thickness of the laminated portion. The battery according to claim 5. [Claim 7] The aforementioned protrusion is branched. The battery according to claim 1. [Claim 8] The side portion has regions on both sides of the protruding portion in a direction parallel to the main surface of the plurality of power generation layers on the side portion, in which at least one current collector does not protrude beyond the end surface of the plurality of power generation layers. The battery according to any one of claims 1 to 7. [Claim 9] The protruding length of the aforementioned protrusion is at least twice the thickness of the laminated portion. The battery according to any one of claims 1 to 7. [Claim 10] The height of the tip of the protrusion from the end face of the plurality of power generation layers is less than or equal to the thickness of the power generation element. The battery according to any one of claims 1 to 7. [Claim 11] The height of the tip of the protrusion from the end face of the plurality of power generation layers is no more than twice the thickness of one of the plurality of power generation layers. The battery according to any one of claims 1 to 7. [Claim 12] The aforementioned multiple power generation layers are electrically connected in parallel. The battery according to any one of claims 1 to 7. [Claim 13] The aforementioned multiple power generation layers are electrically connected in series. The battery according to any one of claims 1 to 7. [Claim 14] The plurality of current collectors include a counter electrode current collector electrically connected to the counter electrode layer and an electrode current collector electrically connected to the electrode layer. The at least one current collector is the counter electrode current collector, The battery further comprises an insulating member covering the electrode layer and the electrode current collector on its side surface. The conductive member covers the insulating member on its side surface and is connected to the protruding portion of the counter electrode current collector. The battery according to claim 12. [Claim 15] The insulating member, on its side surface, is in contact with at least a portion of the solid electrolyte layer. The battery according to claim 14. [Claim 16] The insulating member covers the electrode layer of each of the plurality of power generation layers and the electrode current collector that is electrically connected to the electrode layer of each of the plurality of power generation layers on its side surface. The conductive member is connected to the counter electrode current collector, which is electrically connected to the counter electrode layer of each of the plurality of power generation layers, at its side surface. The battery according to claim 14. [Claim 17] The first step is to prepare a plurality of unit cells, each having a structure in which a power generation layer having an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, and a current collector layer are stacked, A second step of forming a laminate in which a plurality of power generation layers and a plurality of current collectors, each containing a current collection layer, are stacked, wherein the power generation layers are sandwiched between two adjacent current collectors from the plurality of current collectors, the two adjacent power generation layers are stacked via one of the plurality of current collectors, and the plurality of current collectors are non-contact with each other, the second step of stacking the plurality of unit cells and forming a projection on at least one of the plurality of current collectors that protrudes from the end face of the power generation layer on the side surface of the laminate, The third step includes forming a conductive member connected to the main surface of the protruding portion and in contact with the end surface of the electrode layer or counter electrode layer adjacent to the at least one current collector on the side surface, In the second step, when projecting the protrusion and the stacked portion of the at least one current collector, which is located on the end face side of the protrusion and connected to the protrusion, and where the power generation layer is stacked, onto a projection plane perpendicular to the main surface of the power generation layer from the outside of the side portion along a direction parallel to the main surface of the power generation layer, the protrusion is formed such that the projected area of ​​the protrusion is larger than the projected area of ​​the stacked portion. Battery manufacturing method. [Claim 18] In the second step, the protrusion is formed using at least one of the following methods: dissolving the material, partial cutting, polishing, sandblasting, brushing, etching, plasma irradiation, laser irradiation, mechanical cutting, ultrasonic cutting, and pressing. A method for manufacturing a battery according to claim 17.