Battery and method for manufacturing a battery

Abstract

A battery according to one aspect of the present disclosure comprises: a power generation element that has a plurality of battery cells each including an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, said plurality of battery cells being electrically connected in parallel and layered; an electrode insulation member that covers the electrode layers at a first side surface of the power generation element; a counter electrode extraction part that covers the first side surface and the electrode insulation member, and is electrically connected to the counter electrode layers; a counter electrode insulation member that covers the counter electrode layers at a second side surface of the power generation element; an electrode extraction part that covers the second side surface and the counter electrode insulation member, and is electrically connected to the electrode layers; a counter electrode power collection terminal that is connected to the counter electrode extraction part; and an electrode power collection terminal that is connected to the electrode extraction part; wherein the counter electrode power collection terminal and the electrode power collection terminal are provided to the same main surface of the power generation element.

Description

Technical Field

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

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] For conventional batteries, further improvement in battery characteristics is required.

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

Means for Solving the Problems

[0006] A battery according to one aspect of the present disclosure comprises a plurality of battery cells, each containing an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, wherein the plurality of battery cells are electrically connected in parallel and stacked to form a power generation element; an electrode insulating member covering the electrode layer on a first side surface of the power generation element; a counter electrode extraction portion covering the first side surface and the electrode insulating member and electrically connected to the counter electrode layer; an electrode insulating member covering the counter electrode layer on a second side surface of the power generation element; an electrode extraction portion covering the second side surface and the counter electrode insulating member and electrically connected to the electrode layer; a counter electrode current collector terminal connected to the counter electrode extraction portion; and an electrode current collector terminal connected to the electrode extraction portion, wherein the counter electrode current collector terminal and the electrode current collector terminal are provided on the same main surface of the power generation element.

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

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

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

[0010] (Summary of the Present Disclosure) A battery according to one aspect of the present disclosure includes a plurality of battery cells each including an electrode layer, a counter electrode layer, and a solid electrolyte layer positioned between the electrode layer and the counter electrode layer. The plurality of battery cells are electrically connected in parallel and stacked to form a power generation element. An electrode insulating member covers the electrode layer on a first side surface of the power generation element. A counter electrode extraction portion covers the first side surface and the electrode insulating member and is electrically connected to the counter electrode layer. A counter electrode insulating member covers the counter electrode layer on a second side surface of the power generation element. An electrode extraction portion covers the second side surface and the counter electrode insulating member and is electrically connected to the electrode layer. A counter electrode current collecting terminal is connected to the counter electrode extraction portion, and an electrode current collecting terminal is connected to the electrode extraction portion. The counter electrode current collecting terminal and the electrode current collecting terminal are provided on the same main surface of the power generation element.

[0011] Thereby, a high-performance battery can be realized. For example, a battery excellent in mounting property and reliability can be realized.

[0012] Specifically, since the electrode insulating member covers the electrode layer on the first side surface of the power generation element, the occurrence of a short circuit between the electrode layer and the counter electrode layer can be suppressed. Similarly, on the second side surface, since the counter electrode insulating member covers the counter electrode layer, the occurrence of a short circuit between the electrode layer and the counter electrode layer can be suppressed. Further, for example, by electrically connecting all the battery cells in parallel, it is possible to suppress a specific battery cell from being overcharged or overdischarged due to the capacity variation of each battery cell. In this way, the reliability of the battery can be enhanced.

[0013] Moreover, since the counter electrode current collecting terminal and the electrode current collecting terminal are provided on the same main surface, the mounting of the battery becomes easy. For example, the main surface of the power generation element has a larger area than the side surface of the power generation element. Since the current collecting terminals are provided on the surface with a large area, the battery can be mounted over a large area, and the reliability of the connection can be enhanced. Further, for example, according to the wiring layout of the mounting substrate, the shape and arrangement of the current collecting terminals can also be adjusted, so that the degree of freedom in connection can be enhanced.

[0014] Furthermore, since both the positive and negative terminals are located on the same main surface, the battery can be mounted compactly. For example, the pattern of connection terminals (also called the footprint) formed on the mounting substrate can be reduced. In addition, mounting becomes possible with the main surface of the power generation element and the mounting substrate arranged parallel to each other, enabling low-profile mounting on the substrate.

[0015] Furthermore, for example, a battery according to one aspect of the present disclosure may further include an intermediate layer disposed between at least one of the counter electrode current collector terminal and the electrode current collector terminal and the main surface.

[0016] As a result, by providing an intermediate layer, it is possible to achieve effects such as aligning the heights of the counter electrode current collector terminal and the electrode current collector terminal, or ensuring electrical insulation.

[0017] Furthermore, for example, the intermediate layer may be an insulating layer.

[0018] This ensures insulation between the electrode layer or counter electrode layer that constitutes the main surface of the power generation element and the counter electrode current collector terminal or electrode current collector terminal.

[0019] Furthermore, for example, the heights of the counter electrode current collector terminal and the electrode current collector terminal from the main surface may be the same.

[0020] This makes it easier to mount the device on flat surfaces such as circuit boards, and also improves the reliability of the mounting process.

[0021] Furthermore, for example, one of the counter electrode current collector terminal and the electrode current collector terminal may be a different member from the member constituting the main surface, and the other of the counter electrode current collector terminal and the electrode current collector terminal may be a member constituting the main surface.

[0022] This allows for a reduction in the number of parts by utilizing the components that make up the main surface as current collection terminals. Thus, in this specification, "current collection terminals are provided on the main surface" means not only when components different from those that make up the main surface are arranged on the main surface as current collection terminals, but also when the components that make up the main surface themselves are current collection terminals.

[0023] Furthermore, for example, the first side and the second side may face away from each other, and the counter electrode current collector terminal and the electrode current collector terminal may be arranged in this order along the direction from the first side to the second side.

[0024] This allows the widths of the electrode current collector terminal and the counter current collector terminal to be the same as the widths of the electrode extraction section and the counter electrode extraction section. As a result, electrical resistance can be reduced, and it becomes possible to extract large currents.

[0025] Furthermore, for example, the counter electrode layer may include a counter electrode current collector and a counter electrode active material layer located between the counter electrode current collector and the solid electrolyte layer. In the first side surface, the counter electrode current collector may protrude beyond the counter electrode active material layer, and the counter electrode extraction portion may be in contact with the main surface of the counter electrode current collector.

[0026] As a result, the counter electrode extraction portion contacts not only the end face but also the main face of the counter electrode current collector at the protruding portion of the counter electrode current collector, thus increasing the contact area between the counter electrode extraction portion and the counter electrode current collector. This reduces the connection resistance between the counter electrode extraction portion and the counter electrode current collector, improving high-current characteristics. For example, it enables rapid charging of batteries.

[0027] Furthermore, for example, in the first side surface, the counter electrode active material layer may be recessed compared to the electrode layer.

[0028] This allows for an even larger contact area between the counter electrode extraction section and the counter electrode current collector, thereby further reducing the connection resistance between the counter electrode extraction section and the counter electrode current collector.

[0029] Furthermore, for example, the end face on the first side of the counter electrode current collector and the end face on the first side of the electrode layer may coincide when viewed from a direction perpendicular to the main surface.

[0030] This allows for the easy formation of a power generation element by, for example, cutting multiple stacked battery cells together. By using simultaneous cutting, the area of ​​each layer—electrode layer, counter electrode layer, and solid electrolyte layer—is precisely determined, without, for example, a gradual increase or decrease in film thickness at the beginning or end of the coating of each layer. This reduces the variation in battery cell capacity, thereby improving the accuracy of the battery capacity.

[0031] Furthermore, for example, the electrode insulating member may cover at least a portion of the solid electrolyte layer on the first side surface.

[0032] This allows the electrode insulating member to be formed so as to cover a portion of the solid electrolyte layer, thereby preventing the electrode layer from being exposed even if there are variations in the size of the electrode insulating member. Furthermore, since the solid electrolyte layer is generally made of powdered material, its edges have very fine irregularities. This improves the adhesion strength of the electrode insulating member and enhances insulation reliability. In this way, the reliability of the battery can be further enhanced.

[0033] Furthermore, for example, the electrode insulating member may cover at least a portion of the electrode layer to the counter electrode layer on the first side surface.

[0034] This effectively prevents the electrode layer from being exposed without being covered by the electrode insulating material, by covering even a portion of the counter electrode layer. Furthermore, since the counter electrode active material layer is generally made of powdered material, its edge surface has very fine irregularities. This further improves the adhesion strength of the electrode insulating material and enhances insulation reliability. Therefore, the reliability of the battery can be further increased.

[0035] Furthermore, for example, the electrode insulating member may cover the electrode layer of each of the plurality of battery cells on its first side surface, and the counter electrode extraction portion may be electrically connected to the counter electrode layer of each of the plurality of battery cells.

[0036] This allows the counter electrode extraction section to be used for parallel connection of multiple battery cells. Since the counter electrode extraction section can be closely attached to the first side surface and the electrode insulating member, the volume of the parts involved in parallel connection can be reduced. Therefore, the energy density of the battery can be increased.

[0037] Furthermore, for example, the electrode insulating member may have a striped shape in a plan view of the first side surface.

[0038] This allows the end face of the electrode layer, which is exposed in a stripe pattern on the first side surface, to be effectively covered by a stripe-shaped electrode insulating member.

[0039] Furthermore, for example, the electrode layer may include an electrode current collector and an electrode active material layer located between the electrode current collector and the solid electrolyte layer. In the second side view, the electrode current collector may protrude beyond the electrode active material layer, and the electrode extraction portion may be in contact with the main surface of the electrode current collector.

[0040] As a result, the electrode take-off portion contacts not only the end face but also the main face of the electrode current collector at the protruding portion of the electrode current collector, thus increasing the contact area between the electrode take-off portion and the electrode current collector. This reduces the connection resistance between the electrode take-off portion and the electrode current collector, improving high-current characteristics. For example, it enables rapid charging of batteries.

[0041] Furthermore, for example, in the second side surface, the electrode active material layer may be recessed compared to the counter electrode layer.

[0042] This allows for an even larger contact area between the electrode extraction section and the electrode current collector, thereby further reducing the connection resistance between the electrode extraction section and the electrode current collector.

[0043] Furthermore, for example, the counter electrode insulating member may cover the counter electrode layer of each of the plurality of battery cells on its second side surface, and the electrode extraction portion may be electrically connected to the electrode layer of each of the plurality of battery cells.

[0044] This allows the electrode extraction section to be used for parallel connection of multiple battery cells. Since the electrode extraction section can be closely attached to the second side surface and the counter electrode insulating member, the volume of the part involved in parallel connection can be reduced. Therefore, the energy density of the battery can be increased.

[0045] Furthermore, for example, the counter electrode extraction portion may include a first conductive member that contacts the counter electrode layer and a second conductive member that covers the first conductive member.

[0046] This allows the counter electrode extraction section to be formed using multiple materials with different properties. For example, the material used for the first conductive member in contact with the counter electrode layer can be selected based on its high conductivity and alloying with the metal contained in the current collector. The material used for the second conductive member can be selected based on its flexibility, impact resistance, chemical stability, cost, and ease of spreading during installation. In this way, suitable materials can be selected for each component, improving battery performance and ease of manufacturing.

[0047] Furthermore, for example, the electrode insulating member or the counter electrode insulating member may contain resin.

[0048] This improves the shock resistance of the battery. It also reduces the stress on the battery caused by temperature changes or expansion and contraction during charging and discharging.

[0049] Furthermore, for example, the system may further include a sealing member that exposes at least a portion of each of the counter electrode current collector terminal and the electrode current collector terminal, and seals the power generation element, the electrode extraction portion, and the counter electrode extraction portion.

[0050] This protects the power generation elements from the outside air and water, further enhancing the reliability of the battery.

[0051] Furthermore, a battery according to one aspect of the present disclosure includes the steps of: preparing a plurality of battery cells, each containing an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer; forming a laminate by sequentially stacking the plurality of battery cells such that the order of the electrode layer, the counter electrode layer, and the solid electrolyte layer alternates for each battery cell; covering the electrode layer with an electrode insulating member on a first side surface of the laminate, and covering the counter electrode layer with a counter electrode insulating member on a second side surface of the laminate; covering the first side surface and the electrode insulating member with a counter electrode extraction portion electrically connected to the counter electrode layer, and covering the second side surface and the counter electrode insulating member with an electrode extraction portion electrically connected to the electrode layer; and providing a counter electrode current collector terminal connected to the counter electrode extraction portion and an electrode current collector terminal connected to the electrode extraction portion on the same main surface of the laminate.

[0052] This makes it possible to manufacture the high-performance batteries mentioned above.

[0053] The embodiments will be described in detail below with reference to the drawings.

[0054] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, steps, and the order of steps shown in the following embodiments are examples only and are not intended to limit this disclosure. Furthermore, any components in the following embodiments that are not described in an independent claim will be described as optional components.

[0055] The embodiments will be described in detail below with reference to the drawings.

[0056] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, steps, and the order of steps shown in the following embodiments are examples only and are not intended to limit this disclosure. Furthermore, any components in the following embodiments that are not described in an independent claim will be described as optional components.

[0057] 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.

[0058] Furthermore, in this specification, terms indicating relationships between elements such as parallel or orthogonal, terms indicating the shape of elements such as rectangles or cuboids, and numerical ranges do not represent only strict meanings, but also include substantially equivalent ranges, such as differences of a few percent.

[0059] Furthermore, in this specification and the drawings, the x, y, and z axes represent the three axes of a three-dimensional Cartesian coordinate system. The x and y axes correspond to the first side and the second side perpendicular to the first side of a rectangle, respectively, when the plan view shape of the power generation element of the battery is rectangular. The z axis corresponds to the stacking direction of the multiple battery cells included in the power generation element.

[0060] Furthermore, in this specification, the "stacking direction" coincides with the direction normal to the main surface of the current collector and the active material layer. Also, in this specification, "plan view" refers to the view from a direction perpendicular to the main surface of the power generation element, unless otherwise specified, such as when used alone. When it is written as "plan view of a certain surface," such as "plan view of the first side," it refers to the view of that "certain surface" from the front.

[0061] 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."

[0062] Furthermore, in this specification, the expression "cover A" means to cover at least a part of "A". In other words, "cover A" includes not only the case of "covering all of A" but also the case of "covering only a part of A". "A" is, for example, the side and main surface of a predetermined member such as a layer or terminal.

[0063] Furthermore, in this specification, ordinal numbers such as "first" and "second" do not mean the number or order of components unless otherwise specified, but are used to avoid confusion between similar components and to distinguish them.

[0064] (Embodiment 1) The configuration of the battery according to Embodiment 1 will be described below.

[0065] Figure 1 is a cross-sectional view of a battery 1 according to this embodiment. As shown in Figure 1, the battery 1 comprises a power generation element 10, an electrode insulating layer 21, a counter electrode insulating layer 22, a counter electrode extraction section 31, an electrode extraction section 32, a counter electrode current collector terminal 41, an electrode current collector terminal 42, a counter electrode intermediate layer 51, and an electrode intermediate layer 52. The battery 1 is, for example, an all-solid-state battery.

[0066] [1. Power generation elements] First, the specific configuration of the power generation element 10 will be explained using Figures 1 and 2. Figure 2 is a top view of the battery 1 according to this embodiment. Figure 1 shows a cross-section along line II in Figure 2.

[0067] The plan view shape of the power generation element 10 is rectangular, as shown in Figure 2, for example. In other words, the shape of the power generation element 10 is a flattened rectangular parallelepiped. Here, "flattened" means that the thickness (i.e., the length in the z-axis direction) is shorter than the length of each side of the main face (i.e., the respective lengths in the x-axis and y-axis directions) or the maximum width. The plan view shape of the power generation element 10 may also be other polygons such as a square, hexagon, or octagon, or it may be circular or elliptical. Note that in cross-sectional views such as Figure 1, the thickness of each layer is exaggerated to make the layered structure of the power generation element 10 easier to understand.

[0068] The power generation element 10 includes four side surfaces 11, 12, 13, and 14 and two main surfaces 15 and 16, as shown in Figures 1 and 2. In this embodiment, the side surfaces 11, 12, 13, and 14, as well as the main surfaces 15 and 16, are all flat surfaces.

[0069] Side 11 is an example of a first side. Side 12 is an example of a second side. Sides 11 and 12 are facing away from each other and are parallel to each other. Sides 13 and 14 are facing away from each other and are parallel to each other. Sides 11, 12, 13 and 14 are cross-sections formed, for example, by cutting a stack of multiple battery cells 100 all at once.

[0070] The main surfaces 15 and 16 are opposite each other and parallel to each other. Main surface 15 is the uppermost surface of the power generation element 10. Main surface 16 is the lowermost surface of the power generation element 10. The areas of main surfaces 15 and 16 are larger than the areas of the sides 11, 12, 13, and 14, respectively.

[0071] As shown in Figure 1, the power generation element 10 has a plurality of battery cells 100. A battery cell 100 is the smallest battery configuration and is also called a unit cell. The plurality of battery cells 100 are electrically connected in parallel and stacked. In this embodiment, all of the battery cells 100 of the power generation element 10 are electrically connected in parallel. In the example shown in Figure 1, the power generation element 10 has 8 battery cells 100, but is not limited to this. For example, the number of battery cells 100 of the power generation element 10 may be an even number such as 2 or 4, or an odd number such as 3 or 5.

[0072] Each of the multiple battery cells 100 includes an electrode layer 110, a counter electrode layer 120, and a solid electrolyte layer 130. The electrode layer 110 has an electrode current collector 111 and an electrode active material layer 112. The counter electrode layer 120 has a counter electrode current collector 121 and a counter electrode active material layer 122. In each of the multiple battery cells 100, the electrode current collector 111, the electrode active material layer 112, the solid electrolyte layer 130, the counter electrode active material layer 122, and the counter electrode current collector 121 are stacked in this order along the z-axis.

[0073] The electrode layer 110 is one of the positive and negative electrode layers of the battery cell 100. The counter electrode layer 120 is the other of the positive and negative electrode layers of the battery cell 100. In the following explanation, we will describe the case where the electrode layer 110 is the negative electrode layer and the counter electrode layer 120 is the positive electrode layer as an example.

[0074] The configurations of the multiple battery cells 100 are substantially identical to each other. In two adjacent battery cells 100, the order of the layers constituting the battery cell 100 is reversed. In other words, the multiple battery cells 100 are stacked along the z-axis, with the order of the layers constituting the battery cell 100 alternating. In this embodiment, since the number of battery cells 100 is even, the bottom and top layers of the power generation element 10 become current collectors of the same polarity.

[0075] In the following section, Figure 3A will be used to describe each layer of the battery cell 100. Figure 3A is a cross-sectional view of the battery cell 100 included in the power generation element 10 according to this embodiment.

[0076] The electrode current collector 111 and the counter electrode current collector 121 are each conductive foil-shaped, plate-shaped, or mesh-shaped members. The electrode current collector 111 and the counter electrode current collector 121 may each be, for example, conductive thin films. As materials for constituting the electrode current collector 111 and the counter electrode current collector 121, metals such as stainless steel (SUS), aluminum (Al), copper (Cu), and nickel (Ni) can be used. The electrode current collector 111 and the counter electrode current collector 121 may be formed using different materials.

[0077] The thickness of the electrode current collector 111 and the counter electrode current collector 121 is, for example, 5 μm to 100 μm, but is not limited to this. The main surface of the electrode current collector 111 is in contact with the electrode active material layer 112. The electrode current collector 111 may also include a current collector layer containing a conductive material, provided in the portion that is in contact with the electrode active material layer 112. The main surface of the counter electrode current collector 121 is in contact with the counter electrode active material layer 122. The counter electrode current collector 121 may also include a current collector layer containing a conductive material, provided in the portion that is in contact with the counter electrode active material layer 122.

[0078] The electrode active material layer 112 is located on the main surface of the electrode current collector 111, on the side facing the counter electrode layer 120. The electrode active material layer 112 includes, for example, a negative electrode active material as the electrode material. The electrode active material layer 112 is located opposite the counter electrode active material layer 122.

[0079] As the negative electrode active material contained in the electrode active material layer 112, for example, negative electrode active materials such as graphite and metallic lithium can be used. As the material for the negative electrode active material, various materials that can release and insert ions such as lithium (Li) or magnesium (Mg) can be used.

[0080] Furthermore, as the material containing the electrode active material layer 112, a solid electrolyte such as an inorganic solid electrolyte may be used. As an inorganic solid electrolyte, for example, a sulfide solid electrolyte or an oxide solid electrolyte may be used. As a sulfide solid electrolyte, for example, a mixture of lithium sulfide (Li2S) and phosphorus pentasulfide (P2S5) may be used. In addition, as the material containing the electrode active material layer 112, a conductive material such as acetylene black, or a binding binder such as polyvinylidene fluoride may be used.

[0081] The electrode active material layer 112 is produced by applying a paste-like coating, which is made by kneading the materials containing the electrode active material layer 112 together with a solvent, onto the main surface of the electrode current collector 111 and drying it. In order to increase the density of the electrode active material layer 112, the electrode layer 110 (also called an electrode plate), which includes the electrode active material layer 112 and the electrode current collector 111, may be pressed after drying. The thickness of the electrode active material layer 112 is, for example, 5 μm to 300 μm, but is not limited to this.

[0082] The counter electrode active material layer 122 is located on the main surface of the counter electrode current collector 121 on the electrode layer 110 side. The counter electrode active material layer 122 is a layer containing a positive electrode material, such as an active material. The positive electrode material is the material that constitutes the counter electrode of the negative electrode material. The counter electrode active material layer 122 contains, for example, a positive electrode active material.

[0083] As the positive electrode active material contained in the counter electrode active material layer 122, for example, positive electrode active materials such as lithium cobalt oxide composite oxide (LCO), lithium nickel oxide composite oxide (LNO), lithium manganese oxide composite oxide (LMO), lithium-manganese-nickel oxide composite oxide (LMNO), lithium-manganese-cobalt oxide composite oxide (LMCO), lithium-nickel-cobalt oxide composite oxide (LNCO), and lithium-nickel-manganese-cobalt oxide composite oxide (LNMCO) can be used. As the material for the positive electrode active material, various materials that can release and insert ions such as Li or Mg can be used.

[0084] Furthermore, as the material containing the counter electrode active material layer 122, a solid electrolyte such as an inorganic solid electrolyte may be used. As the inorganic solid electrolyte, sulfide solid electrolytes or oxide solid electrolytes may be used. As the sulfide solid electrolyte, for example, a mixture of Li2S and P2S5 may be used. The surface of the positive electrode active material may be coated with a solid electrolyte. Furthermore, as the material containing the counter electrode active material layer 122, a conductive material such as acetylene black, or a binding binder such as polyvinylidene fluoride may be used.

[0085] The counter electrode active material layer 122 is manufactured by applying a paste-like coating, in which the materials containing the counter electrode active material layer 122 are kneaded together with a solvent, onto the main surface of the counter electrode current collector 121 and drying it. In order to increase the density of the counter electrode active material layer 122, the counter electrode layer 120 (also called the counter electrode plate), which includes the counter electrode active material layer 122 and the counter electrode current collector 121, may be pressed after drying. The thickness of the counter electrode active material layer 122 is, for example, 5 μm to 300 μm, but is not limited to this.

[0086] The solid electrolyte layer 130 is placed between the electrode active material layer 112 and the counter electrode active material layer 122. The solid electrolyte layer 130 is in contact with both the electrode active material layer 112 and the counter electrode active material layer 122. The solid electrolyte layer 130 is a layer containing an electrolyte material. As the electrolyte material, generally known electrolytes for batteries can be used. The thickness of the solid electrolyte layer 130 may be 5 μm or more and 300 μm or less, or 5 μm or more and 100 μm or less.

[0087] 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.

[0088] In this embodiment, the electrode active material layer 112, the counter electrode active material layer 122, and the solid electrolyte layer 130 are maintained in a parallel plate shape. This suppresses the occurrence of cracks or collapse due to bending. Alternatively, the electrode active material layer 112, the counter electrode active material layer 122, and the solid electrolyte layer 130 may be smoothly curved together.

[0089] Furthermore, in this embodiment, the end face of the counter electrode layer 120 on the side surface 11 and the end face of the electrode layer 110 on the side surface 11 coincide when viewed from the z-axis direction. Specifically, the end face of the counter electrode current collector 121 on the side surface 11 and the end face of the electrode current collector 111 on the side surface 11 coincide when viewed from the z-axis direction. The same applies to the end faces of the respective side surfaces 12 of the counter electrode current collector 121 and the electrode current collector 111.

[0090] More specifically, in the battery cell 100, the electrode current collector 111, electrode active material layer 112, solid electrolyte layer 130, counter electrode active material layer 122, and counter electrode current collector 121 are all the same in shape and size, and their contours match. In other words, the shape of the battery cell 100 is a flat, rectangular parallelepiped.

[0091] As shown in Figure 1, in this embodiment, two adjacent battery cells 100 share a current collector. For example, the bottommost battery cell 100 and the battery cell 100 above it share one electrode current collector 111.

[0092] Specifically, as shown in Figure 1, in multiple battery cells 100, two adjacent electrode layers 110 share each other's electrode current collectors 111. Electrode active material layers 112 are provided on both sides of the main surface of the shared electrode current collector 111. Similarly, two adjacent counter electrode layers 120 share each other's counter electrode current collectors 121. Counter electrode active material layers 122 are provided on both sides of the main surface of the shared counter electrode current collector 121.

[0093] Such a battery 1 is formed by stacking not only the battery cell 100 shown in Figure 3A, but also battery cells 100B and 100C shown in Figures 3B and 3C. Here, the battery cell 100 shown in Figure 3A will be referred to as battery cell 100A.

[0094] The battery cell 100B shown in Figure 3B has the same configuration as the battery cell 100A shown in Figure 3A, but without the electrode current collector 111. In other words, the electrode layer 110B of the battery cell 100B consists only of the electrode active material layer 112.

[0095] The battery cell 100C shown in Figure 3C has the same configuration as the battery cell 100A shown in Figure 3A, but without the counter electrode current collector 121. In other words, the counter electrode layer 120C of the battery cell 100C consists only of the counter electrode active material layer 122.

[0096] Figure 4 is a cross-sectional view showing the power generation element 10 according to this embodiment. Figure 4 is a view showing only the power generation element 10 from Figure 1. As shown in Figure 4, a battery cell 100A is placed in the bottom layer, and battery cells 100B and 100C are stacked alternately upwards. At this time, the battery cells 100B are stacked in the opposite orientation to that shown in Figure 3B. This forms the power generation element 10.

[0097] The method for forming the power generation element 10 is not limited to this. For example, a battery cell 100A may be placed on the top layer. Alternatively, a battery cell 100A may be placed at a position different from both the top and bottom layers. Multiple battery cells 100A may also be used. Furthermore, by applying double-sided coating to a single current collector, two units of battery cells 100 sharing a current collector may be formed, and these formed units may be stacked.

[0098] As described above, in the power generation element 10 according to this embodiment, all battery cells 100 are connected in parallel, and no battery cells are connected in series. Therefore, when charging and discharging the battery 1, it is less likely that unevenness in the charge and discharge state will occur due to variations in the capacity of the battery cells 100. As a result, the risk of some of the multiple battery cells 100 becoming overcharged or over-discharged can be greatly reduced, and the reliability of the battery 1 can be improved.

[0099] [2. Insulating layer] Next, the electrode insulating layer 21 and the counter electrode insulating layer 22 will be described.

[0100] The electrode insulating layer 21 is an example of an electrode insulating member, and as shown in Figure 1, it covers the electrode layer 110 on the side surface 11. Specifically, the electrode insulating layer 21 completely covers the electrode current collector 111 and the electrode active material layer 112 on the side surface 11.

[0101] Figure 5 is a side view showing the positional relationship between the side surface 11 of the power generation element 10 according to this embodiment and the electrode insulating layer 21 provided on the side surface 11. In Figure 5, the end faces of each layer visible on the side surface 11 are shaded in the same way as the shading shown for each layer in the cross-section of Figure 1. The same applies to Figure 6, which will be described later.

[0102] Figure 5(a) is a side view of the power generation element 10, and a plan view of the side 11 as seen from the front. Figure 5(b) shows the side 11 of Figure 5(a) and the electrode insulating layer 21 provided on the side 11. In other words, Figure 5(b) is a side view of the battery 1 of Figure 1 as seen from the negative side of the x-axis, with the counter electrode extraction part 31 visible through it.

[0103] As shown in Figure 5(b), the electrode insulating layer 21 covers each electrode layer 110 of the multiple battery cells 100 on the side surface 11. The electrode insulating layer 21 does not cover at least a portion of each counter electrode layer 120 of the multiple battery cells 100. For example, the electrode insulating layer 21 does not cover the counter electrode current collector 121. Therefore, the electrode insulating layer 21 has a striped shape in a plan view of the side surface 11.

[0104] In this configuration, the electrode insulating layer 21 continuously covers the electrode layers 110 of two adjacent battery cells 100. Specifically, the electrode insulating layer 21 continuously covers at least a portion of the solid electrolyte layer 130 of one of the two adjacent battery cells 100, and at least a portion of the solid electrolyte layer 130 of the other of the two adjacent battery cells 100.

[0105] Thus, the electrode insulating layer 21 covers at least a portion of the solid electrolyte layer 130 on the side surface 11. Specifically, when the side surface 11 is viewed from above, the contour of the electrode insulating layer 21 overlaps with the solid electrolyte layer 130. This reduces the risk of exposing the electrode layer 110 even if the width (length in the z-axis direction) of the electrode insulating layer 21 fluctuates due to manufacturing variations. Therefore, it is possible to suppress short circuits between the electrode layer 110 and the counter electrode layer 120 via the counter electrode take-up portion 31 which is 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.

[0106] In this embodiment, the electrode insulating layer 21 may cover the entire solid electrolyte layer 130 on its side surface 11. Specifically, the contour of the electrode insulating layer 21 may overlap with the boundary between the solid electrolyte layer 130 and the counter electrode active material layer 122. It is not essential that the electrode insulating layer 21 covers only a portion of the solid electrolyte layer 130. For example, the contour of the electrode insulating layer 21 may overlap with the boundary between the solid electrolyte layer 130 and the electrode active material layer 112.

[0107] In Figure 5(b), the electrode insulating layer 21 is provided separately for each electrode layer 110, but this is not limited to this. For example, the electrode insulating layer 21 may be provided not only in the stripe-shaped portion but also along the z-axis direction at the end of the side surface 11 in the y-axis direction. In other words, the shape of the electrode insulating layer 21 may be ladder-shaped in a plan view of the side surface 11. Thus, the electrode insulating layer 21 may cover a part of the counter electrode current collector 121.

[0108] The counter electrode insulating layer 22 is an example of a counter electrode insulating member, and as shown in Figure 1, it covers the counter electrode layer 120 on the side surface 12. Specifically, the counter electrode insulating layer 22 completely covers the counter electrode current collector 121 and the counter electrode active material layer 122 on the side surface 12.

[0109] Figure 6 is a side view showing the positional relationship between the side surface 12 of the power generation element 10 according to this embodiment and the counter electrode insulating layer 22 provided on the side surface 12. Figure 6(a) is a side view of the power generation element 10, and is a plan view of the side surface 12 as seen from the front. Figure 6(b) shows the side surface 12 of Figure 6(a) and the counter electrode insulating layer 22 provided on the side surface 12. In other words, Figure 6(b) is a side view of the battery 1 in Figure 1 as seen from the positive x-axis side, with the electrode extraction portion 32 visible through it.

[0110] As shown in Figure 6(b), the counter electrode insulating layer 22 covers each of the counter electrode layers 120 of the multiple battery cells 100 on the side surface 12. The counter electrode insulating layer 22 does not cover at least a portion of each of the electrode layers 110 of the multiple battery cells 100. For example, the counter electrode insulating layer 22 does not cover the electrode current collector 111. Therefore, the counter electrode insulating layer 22 has a striped shape in a plan view of the side surface 12.

[0111] In this configuration, the counter electrode insulating layer 22 continuously covers the counter electrode layers 120 of two adjacent battery cells 100. Specifically, the counter electrode insulating layer 22 continuously covers at least a portion of the solid electrolyte layer 130 of one of the two adjacent battery cells 100, and at least a portion of the solid electrolyte layer 130 of the other of the two adjacent battery cells 100.

[0112] Thus, the counter electrode insulating layer 22 covers at least a portion of the solid electrolyte layer 130 on the side surface 12. Specifically, when the side surface 12 is viewed from above, the contour of the counter electrode insulating layer 22 overlaps with the solid electrolyte layer 130. This reduces the risk of exposing the counter electrode layer 120 even if the width (length in the z-axis direction) of the counter electrode insulating layer 22 fluctuates due to manufacturing variations. Therefore, it is possible to suppress short circuits between the counter electrode layer 120 and the electrode layer 110 via the electrode outlet portion 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.

[0113] In this embodiment, the counter electrode insulating layer 22 may cover the entire solid electrolyte layer 130 on its side surface 12. Specifically, the contour of the counter electrode insulating layer 22 may overlap the boundary between the solid electrolyte layer 130 and the electrode active material layer 112. It is not essential that the counter electrode insulating layer 22 covers only a portion of the solid electrolyte layer 130. For example, the contour of the counter electrode insulating layer 22 may overlap the boundary between the solid electrolyte layer 130 and the counter electrode active material layer 122.

[0114] In Figure 6(b), the counter electrode insulating layer 22 is provided separately for each counter electrode layer 120, but this is not limited to this. For example, in addition to the stripe-shaped portion, the counter electrode insulating layer 22 may be provided along the z-axis direction at the end of the side surface 12 in the y-axis direction. In other words, the shape of the counter electrode insulating layer 22 may be ladder-shaped in a plan view of the side surface 12. Thus, the counter electrode insulating layer 22 may cover a part of the electrode current collector 111.

[0115] Furthermore, in the power generation element 10 according to this embodiment, the uppermost and lowermost layers are counter electrode current collectors 121, respectively. As shown in Figures 1 and 6(b), near the upper and lower ends of the side surface 12, the counter electrode insulating layer 22 covers a portion of the main surface of the counter electrode current collector 121 located in the uppermost and lowermost layers, respectively. As a result, the counter electrode insulating layer 22 is resistant to external forces from the z-axis direction, and detachment is suppressed. In addition, even if the electrode extraction portion 32 wraps around to the main surface 15 or 16 of the power generation element 10, it can contact the counter electrode current collector 121, preventing a short circuit. In this way, the reliability of the battery 1 can be improved.

[0116] 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.

[0117] [3. Dispensing Section] Next, the counter electrode extraction section 31 and the electrode extraction section 32 will be described.

[0118] As shown in Figure 1, the counter electrode extraction portion 31 is a conductive portion that covers the side surface 11 and the electrode insulating layer 21 and is electrically connected to the counter electrode layer 120. Specifically, the counter electrode extraction portion 31 covers the electrode insulating layer 21 and the portion of the side surface 11 that is not covered by the electrode insulating layer 21.

[0119] As shown in Figure 5(b), the end faces of the counter electrode current collector 121 and the counter electrode active material layer 122 are exposed in the portion of the side surface 11 that is not covered by the electrode insulating layer 21. Therefore, the counter electrode take-up portion 31 contacts the end faces of the counter electrode current collector 121 and the counter electrode active material layer 122, and is electrically connected to the counter electrode layer 120. Since the counter electrode active material layer 122 is made of a powdered material, it has very fine irregularities, similar to the solid electrolyte layer 130. The contact strength of the counter electrode take-up portion 31 is improved by fitting into the irregularities of the end face of the counter electrode active material layer 122, thereby improving the reliability of the electrical connection.

[0120] The counter electrode extraction section 31 is electrically connected to the counter electrode layer 120 of each of the multiple battery cells 100. In other words, the counter electrode extraction section 31 is responsible for electrically connecting each battery cell 100 in parallel. As shown in Figure 1, the counter electrode extraction section 31 covers almost the entire surface from the lower end to the upper end of the side surface 11.

[0121] In the power generation element 10 according to this embodiment, the uppermost and lowermost layers are counter electrode current collectors 121, respectively. As shown in Figure 1, near the upper and lower ends of the side surface 11, the counter electrode extraction portion 31 covers a portion of the main surface of the counter electrode current collector 121 located in the uppermost and lowermost layers, respectively. As a result, the counter electrode extraction portion 31 is resistant to external forces from the z-axis direction, and detachment is suppressed. In addition, since the contact area between the counter electrode extraction portion 31 and the counter electrode current collector 121 is increased, the connection resistance between the counter electrode extraction portion 31 and the counter electrode current collector 121 is reduced, and the high-current characteristics can be improved. For example, rapid charging of the battery 1 becomes possible.

[0122] As shown in Figure 1, the electrode extraction portion 32 is a conductive portion that covers the side surface 12 and the counter electrode insulating layer 22 and is electrically connected to the electrode layer 110. Specifically, the electrode extraction portion 32 covers the counter electrode insulating layer 22 and the portion of the side surface 12 that is not covered by the counter electrode insulating layer 22.

[0123] As shown in Figure 6(b), the end faces of the electrode current collector 111 and the electrode active material layer 112 are exposed in the portion of the side surface 12 that is not covered by the counter electrode insulating layer 22. Therefore, the electrode take-off portion 32 contacts the end faces of the electrode current collector 111 and the electrode active material layer 112, and is electrically connected to the electrode layer 110. Since the electrode active material layer 112 is made of a powdered material, it has very fine irregularities, similar to the solid electrolyte layer 130. The electrode take-off portion 32 fits into the irregularities of the end face of the electrode active material layer 112, improving the adhesion strength of the electrode take-off portion 32 and improving the reliability of the electrical connection.

[0124] The electrode extraction section 32 is electrically connected to each electrode layer 110 of the multiple battery cells 100. In other words, the electrode extraction section 32 is responsible for electrically connecting each battery cell 100 in parallel. As shown in Figure 1, the electrode extraction section 32 covers almost the entire side surface 12 from the lower end to the upper end.

[0125] The counter electrode extraction section 31 and the electrode extraction section 32 are formed using a conductive resin material or the like. Alternatively, the counter electrode extraction section 31 and the electrode extraction section 32 may be formed using a metallic material such as solder. The usable conductive material is selected based on various properties such as flexibility, gas barrier properties, impact resistance, heat resistance, and solder wettability. The counter electrode extraction section 31 and the electrode extraction section 32 are formed using the same material, but they may be formed using different materials.

[0126] [4. Current collector terminal] Next, the counter electrode current collector terminal 41 and the electrode current collector terminal 42 will be described.

[0127] The counter electrode current collector terminal 41 is a conductive terminal connected to the counter electrode extraction section 31. The counter electrode current collector terminal 41 is one of the external connection terminals of the battery 1, and in this embodiment, it is the positive electrode extraction terminal. As shown in Figure 1, the counter electrode current collector terminal 41 is arranged on the main surface 15 of the power generation element 10 via a counter electrode intermediate layer 51. The counter electrode current collector terminal 41 is in contact with the upper end of the counter electrode extraction section 31.

[0128] The electrode current collector terminal 42 is a conductive terminal connected to the electrode extraction section 32. The electrode current collector terminal 42 is one of the external connection terminals of the battery 1, and in this embodiment, it is the negative electrode extraction terminal. As shown in Figure 1, the electrode current collector terminal 42 is arranged on the main surface 15 of the power generation element 10 via an electrode intermediate layer 52. The electrode current collector terminal 42 is in contact with the upper end of the electrode extraction section 32.

[0129] Thus, in this embodiment, the counter electrode current collector terminal 41 and the electrode current collector terminal 42 are provided on the same main surface 15 of the power generation element 10. As shown in Figure 2, the counter electrode current collector terminal 41 and the electrode current collector terminal 42 are arranged in this order along the direction from side surface 11 to side surface 12 (i.e., the positive direction of the x-axis). Specifically, when the main surface 15 is virtually divided into two regions by an imaginary line parallel to the y-axis, the counter electrode current collector terminal 41 is provided in the negative x-axis region, and the electrode current collector terminal 42 is provided in the positive x-axis region.

[0130] For example, the width (i.e., the length in the y-axis direction) of the counter electrode current collector terminal 41 is more than half the width (i.e., the length in the y-axis direction) of the side surface 11. The width of the counter electrode current collector terminal 41 can be made equal to the width (i.e., the length in the y-axis direction) of the counter electrode extraction section 31. This allows for a wider width in the direction in which current flows from the counter electrode extraction section 31 to the counter electrode current collector terminal 41, thereby reducing resistance and being effective for extracting large currents. The same applies to the electrode current collector terminal 42.

[0131] The counter current collector terminal 41 and the electrode current collector terminal 42 are each formed using a conductive material. For example, the counter current collector terminal 41 and the electrode current collector terminal 42 are metal foils or metal plates made of metals such as copper, aluminum, or stainless steel. Alternatively, the counter current collector terminal 41 and the electrode current collector terminal 42 may be hardened solder.

[0132] [5. Middle Class] Next, the counter electrode intermediate layer 51 and the electrode intermediate layer 52 will be described.

[0133] The counter electrode intermediate layer 51 is positioned between the counter electrode current collector terminal 41 and the main surface 15. In this embodiment, since the main surface 15 is the main surface of the counter electrode current collector 121, it is not necessary to ensure insulation between the counter electrode current collector terminal 41 and the main surface 15. For this reason, the counter electrode intermediate layer 51 may be a conductive layer. Furthermore, the counter electrode intermediate layer 51 may not be provided at all.

[0134] The electrode intermediate layer 52 is positioned between the electrode current collector terminal 42 and the main surface 15. In this embodiment, since the main surface 15 is the main surface of the counter electrode current collector 121, insulation between the electrode current collector terminal 42 and the main surface 15 must be ensured. For this reason, the electrode intermediate layer 52 is an insulating layer.

[0135] In this embodiment, since an electrode intermediate layer 52 is essential between the electrode current collector terminal 42 and the main surface 15, the height of the counter electrode current collector terminal 41 from the main surface 15 tends to differ from the height of the electrode current collector terminal 42 from the main surface 15. By providing the counter electrode intermediate layer 51 and adjusting its thickness, the heights of the electrode current collector terminal 42 and the counter electrode current collector terminal 41 from the main surface 15 can be easily made the same. Alternatively, the thickness of the counter electrode current collector terminal 41 may be the sum of the thickness of the electrode current collector terminal 42 and the electrode intermediate layer 52 without providing the counter electrode intermediate layer 51. By making the heights of the counter electrode current collector terminal 41 and the electrode current collector terminal 42 from the main surface 15 the same, the battery 1 can be easily mounted parallel to the substrate (not shown).

[0136] The shape and size of the counter electrode intermediate layer 51 in plan view are the same as, but not limited to, the counter electrode current collector terminal 41. For example, the counter electrode intermediate layer 51 may be larger or smaller than the counter electrode current collector terminal 41 in plan view. A portion of the counter electrode current collector terminal 41 may be in contact with the main surface 15.

[0137] The shape and size of the electrode intermediate layer 52 in plan view are the same as, but not limited to, the electrode current collector terminal 42. For example, the electrode intermediate layer 52 may be larger than the electrode current collector terminal 42 in plan view.

[0138] The counter electrode intermediate layer 51 and the electrode intermediate layer 52 are formed using, for example, an electrically insulating material. For example, the counter electrode intermediate layer 51 and the electrode intermediate layer 52 each contain a resin. The resin is, for example, an epoxy resin, but is not limited thereto. Inorganic materials may also be used as the insulating material. The counter electrode intermediate layer 51 and the electrode intermediate layer 52 are formed using the same material, but they may also be formed using different materials.

[0139] Furthermore, if the counter electrode intermediate layer 51 is an insulating layer, the counter electrode intermediate layer 51 and the electrode intermediate layer 52 may be a single insulating layer. For example, an insulating layer covering the entire main surface 15 may be provided as the counter electrode intermediate layer 51 and the electrode intermediate layer 52. If the counter electrode intermediate layer 51 is a conductive layer, it can be formed using metal or a conductive resin.

[0140] The counter electrode intermediate layer 51 and the electrode intermediate layer 52 may have additional functions such as impact resistance, corrosion resistance, and waterproofing, in addition to ensuring insulation. Materials suitable for these functions can be used for the counter electrode intermediate layer 51 and the electrode intermediate layer 52. The counter electrode intermediate layer 51 and the electrode intermediate layer 52 may each have a laminated structure of multiple different materials.

[0141] [6. Summary] As described above, in the battery 1 according to this embodiment, a counter electrode current collector terminal 41 and an electrode current collector terminal 42 are provided on the main surface 15 of the power generation element 10. That is, both the positive and negative electrode terminals necessary for extracting current from the power generation element 10 are provided on the same main surface 15. For example, the main surface 15 has a larger area than the sides 11, 12, 13, and 14. Since the terminals are provided on a larger surface, the battery 1 can be mounted over a large area, thereby improving connection reliability. In addition, the shape and arrangement of the terminals can be adjusted according to the wiring layout of the substrate to be mounted, thus increasing the degree of connection flexibility.

[0142] Furthermore, since both the positive and negative terminals are located on the same main surface, the battery 1 can be compactly mounted. For example, the pattern of connection terminals (also called the footprint) formed on the mounting board can be reduced. In addition, mounting is possible with the main surface 15 of the battery 1 and the mounting board positioned parallel to each other, enabling low-profile mounting on the mounting board. Reflow soldering connections can be used for mounting. In this way, a battery 1 with excellent mountability can be realized.

[0143] Furthermore, the counter electrode extraction section 31 and the electrode extraction section 32 each serve the function of connecting multiple battery cells 100 in parallel. As shown in Figure 1, the counter electrode extraction section 31 and the electrode extraction section 32 are formed to closely cover the sides 11 and 12 of the power generation element 10, respectively, so their volumes can be reduced. In other words, since the volume of the extraction section is smaller compared to the tab electrodes used for current collection in the past, the energy density per unit volume of the battery 1 can be improved.

[0144] Furthermore, since the counter electrode current collector terminal 41, which is a different component from the counter electrode current collector 121 located in the uppermost layer, is provided via the counter electrode intermediate layer 51, which is an insulating layer, current concentration on the uppermost counter electrode current collector 121 can be suppressed. If current concentration occurs on the counter electrode current collector 121, the temperature rise due to the heat generated by the current may cause the counter electrode current collector 121 to peel off, and the deterioration of the uppermost battery cell 100 may be accelerated. According to this embodiment, the counter electrode extraction section 31 and the counter electrode current collector terminal 41, as well as the electrode extraction section 32 and the electrode current collector terminal 42, are used as current paths from each battery cell 100. Therefore, current concentration on the uppermost counter electrode current collector 121 can be suppressed, and the reliability of the battery 1 can be improved.

[0145] (Embodiment 2) Next, Embodiment 2 will be described.

[0146] In the battery according to Embodiment 2, the arrangement of the counter electrode current collector terminal and the electrode current collector terminal differs from that of the battery according to Embodiment 1. Below, we will focus on explaining the differences from Embodiment 1, and will omit or simplify the explanation of the common points.

[0147] Figure 7 is a top view of the battery 201 according to this embodiment. As shown in Figure 7, compared to the battery 1 according to Embodiment 1, the battery 201 is equipped with a counter electrode current collector terminal 241 and an electrode current collector terminal 242 instead of the counter electrode current collector terminal 41 and the electrode current collector terminal 42. Also, the battery 201 is equipped with an electrode intermediate layer 252 instead of the electrode intermediate layer 52. The battery 201 does not have a counter electrode intermediate layer 51.

[0148] The counter electrode current collector terminal 241 and the electrode current collector terminal 242 are arranged along a direction parallel to the side surface 11 (i.e., in the y-axis direction). Specifically, when the main surface 15 is virtually divided into two regions by an imaginary line parallel to the x-axis, the counter electrode current collector terminal 241 is provided in the negative y-axis region, and the electrode current collector terminal 242 is provided in the positive y-axis region.

[0149] For example, the width (i.e., length in the y-axis direction) of the counter electrode current collector terminal 241 is less than half the width of the side surface 11. On the other hand, the length (i.e., length in the x-axis direction) of the counter electrode current collector terminal 241 is, for example, more than half the length of the side surface 14. The same applies to the electrode current collector terminal 242. In this embodiment, since the counter electrode intermediate layer 51 is not provided, the counter electrode current collector terminal 241 is provided in contact with the main surface 15.

[0150] The electrode intermediate layer 252 is larger than the electrode current collector terminal 242 in a plan view of the main surface 15. For example, if the main surface 15 is virtually divided into two regions by an imaginary line parallel to the x-axis, the electrode intermediate layer 252 occupies almost the entire region on the positive side of the y-axis. Part of the contour of the electrode intermediate layer 252 in a plan view coincides with the side surface 13. In other words, the end face of the electrode intermediate layer 252 on the positive side of the y-axis is flush with the side surface 13.

[0151] As will be described in detail later, the side surface 13 can be formed by cutting a stack of multiple battery cells 100 all at once. By forming an insulating material corresponding to the electrode intermediate layer 252 on the main surface 15 before cutting, the electrode intermediate layer 252 can also be cut all at once. This makes it easy to form the end face of the electrode intermediate layer 252 flush with the side surface 13. In other words, since the electrode intermediate layer 252, which is an insulating layer, can be easily formed on the main surface 15 without any gaps, the possibility of the electrode current collector terminal 242 contacting the uppermost counter electrode current collector 121 can be sufficiently reduced. That is, even if the electrode current collector terminal 242 is formed to be slightly larger due to manufacturing variations, it will be less likely to protrude from the electrode intermediate layer 252 and contact the counter electrode current collector 121. In this way, a highly reliable battery 201 can be realized.

[0152] (Embodiment 3) Next, Embodiment 3 will be described.

[0153] The battery according to Embodiment 3 differs from the battery according to Embodiment 1 in that it uses the uppermost counter electrode current collector as the counter electrode current collector terminal. Below, we will mainly explain the differences from Embodiment 1, and the explanation of the common points will be omitted or simplified.

[0154] Figure 8 is a cross-sectional view of the battery 301 according to this embodiment. As shown in Figure 8, the battery 301 does not have a counter electrode current collector terminal 41 and a counter electrode intermediate layer 51 compared to the battery 1 according to Embodiment 1.

[0155] In the battery 301 according to this embodiment, a portion of the uppermost counter electrode current collector 121 functions as a counter electrode current collector terminal 341. In other words, the counter electrode current collector terminal 341 is a component that constitutes the main surface 15, i.e., the uppermost counter electrode current collector 121. On the other hand, the electrode current collector terminal 42 is a component different from the uppermost counter electrode current collector 121 that constitutes the main surface 15, similar to Embodiment 1.

[0156] In this way, by having the uppermost counter-pole current collector 121 function as the counter-pole current collector terminal 341, the number of parts can be reduced.

[0157] Furthermore, the thickness of the uppermost counter electrode current collector 121 may be greater than that of the other counter electrode current collectors 121. This reduces the resistance of the uppermost counter electrode current collector 121, thereby suppressing heat generation due to current concentration. Alternatively, in addition to thickness, a highly conductive material may be used for the uppermost counter electrode current collector 121.

[0158] (Embodiment 4) Next, Embodiment 4 will be described.

[0159] The battery according to Embodiment 4 differs from the battery according to Embodiment 1 in that the extraction portion is formed using multiple different materials. Below, we will focus on explaining the differences from Embodiment 1, and omit or simplify the explanation of the common points.

[0160] Figure 9 is a cross-sectional view of the battery 401 according to this embodiment. As shown in Figure 9, compared to the battery 1 according to Embodiment 1, the battery 401 is equipped with a counter electrode extraction section 431 and an electrode extraction section 432 instead of a counter electrode extraction section 31 and an electrode extraction section 32.

[0161] The counter electrode extraction section 431 includes a first conductive member 431a and a second conductive member 431b. The second conductive member 431b is the same as the counter electrode extraction section 31 according to Embodiment 1, except that it covers the first conductive member 431a. In this embodiment, the second conductive member 431b is connected to the counter electrode current collector terminal 41.

[0162] The first conductive member 431a is a conductive member that covers at least a portion of the counter electrode layer 120 on the side surface 11. Specifically, the first conductive member 431a covers the end face of the counter electrode current collector 121 and a portion of the end face of the counter electrode active material layer 122 in contact with each other. For example, the first conductive member 431a is provided for each counter electrode current collector 121 and covers the entire end face of the counter electrode current collector 121. In a plan view of the side surface 11, the first conductive member 431a and the electrode insulating layer 21 are arranged alternately one by one along the z-axis direction on the side surface 11.

[0163] Each of the multiple first conductive members 431a is covered by and electrically connected to the second conductive member 431b. In other words, each counter electrode layer 120 of the multiple battery cells 100 is electrically connected to the second conductive member 431b via each first conductive member 431a, and electrically connected in parallel via the second conductive member 431b.

[0164] The first conductive member 431a has different properties from the second conductive member 431b. For example, the first conductive member 431a and the second conductive member 431b are formed using different materials. Specifically, the first conductive member 431a is formed using a material selected primarily for its high conductivity and alloying with the counter electrode current collector 121. The second conductive member 431b is formed using a material selected primarily for its flexibility, impact resistance, chemical stability, cost, and ease of spreading during installation.

[0165] The electrode extraction section 432 includes a first conductive member 432a and a second conductive member 432b. The second conductive member 432b is the same as the electrode extraction section 32 according to Embodiment 1, except that it covers the first conductive member 432a. In this embodiment, the second conductive member 432b is connected to the electrode current collection terminal 42.

[0166] The first conductive member 432a is a conductive member that covers at least a portion of the electrode layer 110 on the side surface 12. Specifically, the first conductive member 432a covers the end face of the electrode current collector 111 and a portion of the end face of the electrode active material layer 112 in contact with it. For example, the first conductive member 432a is provided for each electrode current collector 111 and covers the entire end face of the electrode current collector 111. In a plan view of the side surface 12, the first conductive member 432a and the counter electrode insulating layer 22 are arranged alternately one by one along the z-axis direction on the side surface 12.

[0167] Each of the multiple first conductive members 432a is covered by and electrically connected to the second conductive member 432b. In other words, each electrode layer 110 of the multiple battery cells 100 is electrically connected to the second conductive member 432b via each first conductive member 432a, and electrically connected in parallel via the second conductive member 432b.

[0168] The first conductive member 432a has different properties from the second conductive member 432b. For example, the first conductive member 432a and the second conductive member 432b are formed using different materials. Specifically, the first conductive member 432a is formed using a material selected primarily for its high conductivity and alloying with the electrode current collector 111. The second conductive member 432b is formed using a material selected primarily for its flexibility, impact resistance, chemical stability, cost, and ease of spreading during installation.

[0169] As described above, an appropriate material can be used for the battery outlet of the battery 401, thereby improving the battery's performance and ease of manufacturing.

[0170] In Figure 9, an example is shown in which the first conductive member 431a is connected to all counter electrode current collectors 121. However, there may be counter electrode current collectors 121 to which the first conductive member 431a is not connected. The same applies to the electrode current collectors 111. Furthermore, one of the first conductive members 431a and 432a may be omitted.

[0171] (Embodiment 5) Next, Embodiment 5 will be described.

[0172] The battery according to Embodiment 5 differs from the battery according to Embodiment 1 in that it includes a sealing member. Below, we will focus on explaining the differences from Embodiment 1, and omit or simplify the explanation of the common points.

[0173] Figure 10 is a cross-sectional view of the battery 501 according to this embodiment. Figure 11 is a top view of the battery 501 according to this embodiment. Note that Figure 10 represents a cross-section along line XX in Figure 11. As shown in Figures 10 and 11, the battery 501 includes a sealing member 560 compared to the battery 1 according to Embodiment 1.

[0174] The sealing member 560 exposes at least a portion of each of the counter electrode current collector terminal 41 and the electrode current collector terminal 42, and seals the power generation element 10. The sealing member 560 is provided such that, for example, the power generation element 10, the electrode insulating layer 21, the counter electrode insulating layer 22, the counter electrode take-up portion 31, and the electrode take-up portion 32 are not exposed.

[0175] The sealing member 560 is formed using, for example, an electrically insulating insulating material. As the insulating material, generally known materials for sealing members of batteries, such as encapsulants, may be used. As the insulating material, for example, a resin material may be used. The insulating material may be an insulating material that does not have ionic conductivity. For example, the insulating material may be at least one of epoxy resin, acrylic resin, polyimide resin, and silsesquioxane.

[0176] The sealing member 560 may include multiple different insulating materials. For example, the sealing member 560 may have a multilayer structure. Each layer of the multilayer structure may be formed using a different material and have different properties.

[0177] The sealing member 560 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 560 may be formed using a resin material in which multiple particles made of metal oxide material are dispersed.

[0178] The particle size of the metal oxide material should be less than or equal to the distance between the electrode current collector 111 and the counter electrode current collector 121. The particle shape of the metal oxide material may be, for example, spherical, ellipsoidal, or rod-shaped, but is not limited to these.

[0179] The provision of the sealing member 560 improves the reliability of the battery 501 in various aspects, including mechanical strength, short-circuit prevention, and moisture resistance.

[0180] (Embodiment 6) Next, Embodiment 6 will be described.

[0181] The battery according to Embodiment 6 differs from the battery according to Embodiment 1 in that the current collector contained in the battery cell protrudes more than the active material layer. Below, we will mainly explain the differences from Embodiment 1, and the explanation of the common points will be omitted or simplified.

[0182] Figure 12 is a cross-sectional view of a battery 601 according to this embodiment. As shown in Figure 12, the power generation element 10 of the battery 601 has a battery cell 600 instead of a battery cell 100, compared to the battery 1 shown in Figure 1.

[0183] Each of the multiple battery cells 600 includes an electrode layer 610, a counter electrode layer 620, and a solid electrolyte layer 130. The electrode layer 610 has an electrode current collector 611 and an electrode active material layer 112. The counter electrode layer 620 has a counter electrode current collector 621 and a counter electrode active material layer 122.

[0184] As shown in Figure 12, on the side surface 11, the counter electrode current collector 621 protrudes beyond the counter electrode active material layer 122. In this embodiment, on the side surface 11, the end faces of the counter electrode active material layer 122, the solid electrolyte layer 130, the electrode active material layer 112, and the electrode current collector 611 are flush and form a flat surface. The counter electrode current collector 621 protrudes outward from this flat surface. "Outward" refers to the direction away from the center of the power generation element 10, and for example, when the side surface 11 is used as the reference, it corresponds to the negative direction of the x-axis.

[0185] The protrusion of the counter electrode current collector 621 causes the counter electrode take-up portion 31 to contact the main surface of the protruding portion 621a of the counter electrode current collector 621. The protruding portion 621a is a part of the counter electrode current collector 621 and is located on the negative side of the x-axis, further than the end face on the negative side of the x-axis of the counter electrode active material layer 122. This increases the contact area between the counter electrode take-up portion 31 and the counter electrode current collector 621, thereby reducing the connection resistance.

[0186] The amount of protrusion of the counter electrode current collector 621, that is, the length of the protrusion 621a in the x-axis direction, is not particularly limited. For example, the amount of protrusion of the counter electrode current collector 621 is 4.5 times or more the thickness of the counter electrode current collector 621 (i.e., the length in the z-axis direction). As a result, in this embodiment, since the counter electrode extraction portion 31 is in contact with both main surfaces of the protrusion 621a, the contact area can be increased to more than 10 times compared to the case where the counter electrode current collector 621 does not protrude.

[0187] Alternatively, the amount of protrusion of the counter electrode current collector 621 may be 9 times or more the thickness of the counter electrode current collector 621. This makes it possible to increase the contact area by more than 10 times compared to the case where the counter electrode take-up portion 31 is in contact with only one side of the main surface of the protrusion 621a.

[0188] In this embodiment, the electrode current collector 611 has a similar configuration on the side surface 12. That is, on the side surface 12, the electrode current collector 611 protrudes beyond the electrode active material layer 112. In this embodiment, on the side surface 12, the end faces of the electrode active material layer 112, the solid electrolyte layer 130, the counter electrode active material layer 122, and the counter electrode current collector 621 are flush and form a flat surface. The electrode current collector 611 protrudes outward from this flat surface (specifically, in the positive direction of the x-axis).

[0189] As the electrode current collector 611 protrudes, the electrode take-off portion 32 contacts the main surface of the protruding portion 611a of the electrode current collector 611. The protruding portion 611a is a part of the electrode current collector 611 and is located on the positive side of the x-axis, beyond the end face on the positive side of the x-axis of the electrode active material layer 112. This increases the contact area between the electrode take-off portion 32 and the electrode current collector 611, thereby reducing the connection resistance.

[0190] The amount of protrusion of the electrode current collector 611, that is, the length of the protrusion 611a in the x-axis direction, is not particularly limited. For example, the amount of protrusion of the electrode current collector 611 may be 4.5 times or more the thickness of the electrode current collector 611, or it may be 9 times or more, similar to the counter electrode current collector 621.

[0191] The protrusions 611a and 621a are formed by not placing the counter electrode active material layer 122 or the electrode active material layer 112 at the ends of the current collector, respectively. Alternatively, they are formed by forming the counter electrode active material layer 122 or the electrode active material layer 112 over the entire surface of the current collector and then removing the ends. Removal can be performed, for example, by cutting only the current collector, polishing, sandblasting, brushing, etching, or plasma irradiation. In this case, a portion of the counter electrode active material layer 122 or the electrode active material layer 112 may remain without being removed.

[0192] As described above, with the battery 601 according to this embodiment, the contact area between the current collector and the output section is increased, thus reducing the connection resistance. Therefore, the high-current characteristics of the battery 601 can be improved, and for example, rapid charging becomes possible.

[0193] In this embodiment, an example is shown in which the counter electrode current collector 621 and the electrode current collector 611 each protrude, but it is also possible for only one of them to protrude.

[0194] (Embodiment 7) Next, Embodiment 7 will be described.

[0195] The battery according to Embodiment 7 differs from the battery according to Embodiment 1 in that, on the side of the power generation element, the active material layer and other components not covered by the insulating layer are recessed relative to the current collector. Below, we will mainly explain the differences from Embodiment 1, and the explanation of the common points will be omitted or simplified.

[0196] Figure 13 is a cross-sectional view of a battery 701 according to this embodiment. As shown in Figure 13, the power generation element 10 of the battery 701 has a battery cell 700 instead of a battery cell 100, compared to the battery 1 shown in Figure 1.

[0197] Each of the multiple battery cells 700 includes an electrode layer 710, a counter electrode layer 720, and a solid electrolyte layer 730. The electrode layer 710 has an electrode current collector 111 and an electrode active material layer 712. The counter electrode layer 720 has a counter electrode current collector 121 and a counter electrode active material layer 722.

[0198] As shown in Figure 13, on the side surface 11, the counter electrode active material layer 722 is recessed compared to the electrode layer 710. Furthermore, the counter electrode active material layer 722 is recessed compared to the counter electrode current collector 121. Specifically, the counter electrode active material layer 722 is recessed inward compared to both the electrode layer 710 and the counter electrode current collector 121. "Inward" refers to the direction toward the center of the power generation element 10, and for example, when the side surface 11 is used as a reference, it corresponds to the positive x-axis direction.

[0199] In this embodiment, at least a portion of the solid electrolyte layer 730 is recessed from the electrode layer 710 on the side surface 11. Specifically, the portion of the end face of the solid electrolyte layer 730 that is not covered by the electrode insulating layer 21 is inclined obliquely with respect to the z-axis direction.

[0200] Because the counter electrode active material layer 722 is recessed, the counter electrode current collector 121 protrudes relatively. This protrusion of the counter electrode current collector 121 causes the counter electrode take-up portion 31 to contact the main surface of the protruding portion 721a of the counter electrode current collector 121. This increases the contact area between the counter electrode take-up portion 31 and the counter electrode current collector 121, thereby reducing their connection resistance.

[0201] The amount of recession of the counter electrode active material layer 722, that is, the amount of protrusion of the counter electrode current collector 121, is not particularly limited. For example, as in Embodiment 6, the amount of recession of the counter electrode active material layer 722 may be 4.5 times or more the thickness of the counter electrode current collector 121, or it may be 9 times or more.

[0202] In this embodiment, the electrode active material layer 712 has a similar configuration on the side surface 12. That is, on the side surface 12, the electrode active material layer 712 is recessed compared to the counter electrode layer 720. Furthermore, the electrode active material layer 712 is recessed compared to the electrode current collector 111. Specifically, the electrode active material layer 712 is recessed inward (specifically in the negative x-axis direction) compared to both the counter electrode layer 720 and the electrode current collector 111.

[0203] In this embodiment, at least a portion of the solid electrolyte layer 730 is recessed from the counter electrode layer 720 on the side surface 12. Specifically, the portion of the end face of the solid electrolyte layer 730 that is not covered by the counter electrode insulating layer 22 is inclined obliquely with respect to the z-axis direction.

[0204] Because the electrode active material layer 712 is recessed, the electrode current collector 111 protrudes relatively. This protrusion of the electrode current collector 111 causes the electrode take-off portion 32 to contact the main surface of the protruding portion 711a of the electrode current collector 111. This increases the contact area between the electrode take-off portion 32 and the electrode current collector 111, thereby reducing their connection resistance.

[0205] The amount of recession of the electrode active material layer 712, that is, the amount of protrusion of the electrode current collector 111, is not particularly limited. For example, as in Embodiment 6, the amount of recession of the electrode active material layer 712 may be 4.5 times or more the thickness of the electrode current collector 111, or 9 times or more.

[0206] Furthermore, the retreat of the active material layer is performed by the same method as the method used to make the current collector protrude in Embodiment 6. For example, the retreat of the active material layer is performed by cutting only the current collector, polishing, sandblasting, brushing, etching, or plasma irradiation.

[0207] In this embodiment, in a plan view, the electrode current collector 111 and the counter electrode current collector 121 are the same size and shape, and their contours coincide. Therefore, as shown in Figure 13, in a cross-sectional view, the ends of the electrode current collector 111 and the counter electrode current collector 121 are aligned in the z-axis direction. As will be described in detail in the description of the manufacturing method, after forming a laminate by stacking multiple battery cells 100, the contours of the electrode current collector 111 and the counter electrode current collector 121 coincide by cutting the laminate all at once. Subsequently, the end faces of the active material layer are recessed to manufacture the battery 701 according to this embodiment. In this way, simultaneous processing of each battery cell 700, such as cutting all at once, can be performed, so that variations in the characteristics of each battery cell 700 can be suppressed.

[0208] As described above, with the battery 701 according to this embodiment, the contact area between the current collector and the output section is increased, thus reducing the connection resistance. Therefore, the high-current characteristics of the battery 701 can be improved, and for example, rapid charging becomes possible.

[0209] In this embodiment, an example is shown in which the counter electrode active material layer 722 and the electrode active material layer 712 are recessed, but only one of them may be recessed. Also, the solid electrolyte layer 730 does not need to be recessed on at least one of its sides 11 and 12.

[0210] (Embodiment 8) Next, Embodiment 8 will be described.

[0211] The battery according to Embodiment 8 differs from the battery according to Embodiment 1 in the extent to which the electrode insulating layer and the counter electrode insulating layer cover. Below, we will focus on explaining the differences from Embodiment 1, and omit or simplify the explanation of the common points.

[0212] Figure 14 is a cross-sectional view of the battery 801 according to this embodiment. As shown in Figure 14, the battery 801 comprises an electrode insulating layer 821 and a counter electrode insulating layer 822 instead of the electrode insulating layer 21 and counter electrode insulating layer 22, compared to the battery 1 shown in Figure 1.

[0213] As shown in Figure 14, the electrode insulating layer 821 covers not only the electrode layer 110 but also a portion of the solid electrolyte layer 130 and the counter electrode layer 120 on the side surface 11. In other words, the electrode insulating layer 821 covers from the electrode layer 110 to a portion of the counter electrode layer 120. Specifically, the electrode insulating layer 821 covers a portion of the counter electrode active material layer 122. In this embodiment, the electrode insulating layer 821 continuously covers at least a portion of the counter electrode active material layer 122 of one of two adjacent battery cells 100 to at least a portion of the counter electrode active material layer 122 of the other of the two adjacent battery cells 100. For example, the electrode insulating layer 821 completely covers one electrode current collector 111, the electrode active material layers 112 located on both sides of one electrode current collector 111, and the two solid electrolyte layers 130. For example, when the side surface 11 is viewed from above, the contour of the electrode insulating layer 821 overlaps with the counter electrode active material layer 122.

[0214] As a result, even if the width (length in the z-axis direction) of the electrode insulating layer 821 fluctuates due to manufacturing variations, the risk of exposing the electrode layer 110 is extremely low. Therefore, it is possible to suppress short circuits between the electrode layer 110 and the counter electrode layer 120 via the counter electrode extraction section 31. In addition, as the electrode insulating layer 821 fits into the irregularities on the end face of the counter electrode active material layer 122, the adhesion strength of the electrode insulating layer 821 is improved, and the insulation reliability is enhanced.

[0215] Furthermore, the electrode insulating layer 821 may completely cover the counter electrode active material layer 122 on the side surface 11. Specifically, the contour of the electrode insulating layer 821 may overlap the boundary between the counter electrode active material layer 122 and the counter electrode current collector 121.

[0216] In this embodiment, the counter electrode insulating layer 822 has a similar configuration on the side surface 12. Specifically, on the side surface 12, the counter electrode insulating layer 822 covers not only the counter electrode layer 120 but also a portion of the solid electrolyte layer 130 and the electrode layer 110. In other words, the counter electrode insulating layer 822 covers from the counter electrode layer 120 to a portion of the electrode layer 110. Specifically, the counter electrode insulating layer 822 covers a portion of the electrode active material layer 112. In this embodiment, the counter electrode insulating layer 822 continuously covers from at least a portion of the electrode active material layer 112 of one of two adjacent battery cells 100 to at least a portion of the electrode active material layer 112 of the other of the two adjacent battery cells 100. For example, the counter electrode insulating layer 822 completely covers one counter electrode current collector 121, the counter electrode active material layers 122 located on both sides of one counter electrode current collector 121, and the two solid electrolyte layers 130.

[0217] For example, when the side surface 12 is viewed from above, the contour of the counter electrode insulating layer 822 overlaps with the electrode active material layer 112. As a result, even if the width (length in the z-axis direction) of the counter electrode insulating layer 822 fluctuates due to manufacturing variations, the risk of exposing the counter electrode layer 120 is extremely low. Therefore, it is possible to suppress short circuits between the counter electrode layer 120 and the electrode layer 110 via the electrode extraction section 32. In addition, as the counter electrode insulating layer 822 fits into the irregularities on the end face of the electrode active material layer 112, the adhesion strength of the counter electrode insulating layer 822 is improved, and the insulation reliability is enhanced.

[0218] Furthermore, the counter electrode insulating layer 822 may completely cover the electrode active material layer 112 on the side surface 12. Specifically, the contour of the counter electrode insulating layer 822 may overlap the boundary between the electrode active material layer 112 and the electrode current collector 111.

[0219] (Manufacturing method) Next, a description of the battery manufacturing method according to each of the embodiments described above will be provided.

[0220] Figure 15 is a flowchart showing an example of a battery manufacturing method according to each embodiment. Below, an example of battery 1 according to Embodiment 1 will be described.

[0221] As shown in Figure 15, first, several battery cells are prepared (S10). The battery cells to be prepared are, for example, battery cells 100A, 100B, and 100C shown in Figures 3A to 3C.

[0222] Next, multiple battery cells 100 are stacked (S20). Specifically, a laminate is formed by stacking multiple battery cells 100 in order such that the order of the electrode layer 110, counter electrode layer 120, and solid electrolyte layer 130 alternates. In this embodiment, a power generation element 10 shown in Figure 4 is formed by stacking battery cells 100A, 100B, and 100C in appropriate combinations. The power generation element 10 is an example of a laminate.

[0223] Furthermore, after stacking multiple battery cells 100, the sides of the power generation element 10 may be flattened. For example, by cutting the stack of multiple battery cells 100 all at once, a power generation element 10 with flat sides can be formed. The cutting process can be performed, for example, by a blade, laser, or jet.

[0224] Next, an insulating layer is formed on the side surface of the power generation element 10 (S30). Specifically, an electrode insulating layer 21 is formed on the side surface 11 to cover the electrode layer 110. Also, a counter electrode insulating layer 22 is formed on the side surface 12 to cover the counter electrode layer 120.

[0225] 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.

[0226] Furthermore, when forming the electrode insulating layer 21 and the counter electrode insulating layer 22, a protective member may be formed in areas where the insulating layer should not be formed, such as by masking with tape or by resist treatment, so that the end faces of the counter electrode current collector 121 and the end faces of the electrode current collector 111 are not insulated. After the formation of the electrode insulating layer 21 and the counter electrode insulating layer 22, the conductivity of each current collector can be ensured by removing the protective member.

[0227] Next, an extraction section is formed on the side surface of the power generation element 10 (S40). Specifically, a counter electrode extraction section 31 is formed so as to cover the side surface 11 and the electrode insulating layer 21, and is electrically connected to a plurality of counter electrode layers 120. An electrode extraction section 32 is formed so as to cover the side surface 12 and the counter electrode insulating layer 22, and is electrically connected to a plurality of electrode layers 110.

[0228] For example, the counter electrode outlet 31 is formed by applying a conductive paste, such as a conductive resin, to cover the electrode insulating layer 21 and the portion of the side surface 11 not covered by the electrode insulating layer 21, and then curing it. The electrode outlet 32 ​​is positioned by applying a conductive resin to cover the counter electrode insulating layer 22 and the portion of the side surface 12 not covered by the counter electrode insulating layer 22, and then curing it. The counter electrode outlet 31 and the electrode outlet 32 ​​may be formed by methods such as printing, plating, vapor deposition, sputtering, welding, soldering, joining, or other methods.

[0229] Next, current collector terminals are formed on the main surface 15 of the power generation element 10 (S50). Specifically, a counter electrode current collector terminal 41 is formed on the main surface 15 via a counter electrode intermediate layer 51, and an electrode current collector terminal 42 is formed via an electrode intermediate layer 52. The counter electrode current collector terminal 41 and the electrode current collector terminal 42 are formed by placing a conductive material such as a metal material in a desired area by plating, printing, or soldering. Alternatively, the counter electrode current collector terminal 41 and the electrode current collector terminal 42 may be formed by welding or joining metal plates or the like.

[0230] The counter electrode intermediate layer 51 and the electrode intermediate layer 52 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.

[0231] Through the above process, the battery 1 shown in Figure 1 can be manufactured.

[0232] In addition, the process of pressing the multiple battery cells 100 prepared in step S10 individually, or after stacking the multiple battery cells, in the stacking direction may be performed.

[0233] Furthermore, the counter electrode intermediate layer 51 and the electrode intermediate layer 52 may be formed in step S30 following the formation of the electrode insulating layer 21 and the counter electrode insulating layer 22, or simultaneously with the formation of the electrode insulating layer 21 and the counter electrode insulating layer 22. Alternatively, the counter electrode intermediate layer 51 and the electrode intermediate layer 52 may be formed after the formation of the laminate (S20) but before the sides are cut.

[0234] Furthermore, after the formation of the laminate (S20) and before the formation of the removal section (S40), the first conductive members 431a and 432a shown in Figure 9 may be formed. The first conductive members 431a and 432a may be formed by, for example, printing, plating, vapor deposition, sputtering, welding, soldering, joining, or other methods.

[0235] Furthermore, the end face recession process may be performed after the formation of the laminate (S20) or after the formation of the insulating layer (S30). Specifically, the current collector is made to protrude beyond the active material layer by recessing the end face of the active material layer of the power generation element 10. More specifically, on the side surface 11 of the power generation element 10, the counter electrode current collector 121, which is part of the counter electrode layer 120, is made to protrude beyond the counter electrode active material layer 122, which is another part of the counter electrode layer 120.

[0236] In the end face recession process, for example, polishing, sandblasting, brushing, etching, or plasma irradiation of the side surface 11 is performed. In this case, the electrode insulating layer 21 functions as a protective member against each process. For example, when sandblasting is performed on the side surface 11, the portion covered by the electrode insulating layer 21 is not polished, while the portion not covered by the electrode insulating layer 21, specifically the end surface of the counter electrode layer 120, is scraped and recessed. At this time, since the counter electrode active material layer 122 is more brittle than the counter electrode current collector 121, more of it is removed than the counter electrode current collector 121. As a result, the counter electrode active material layer 122 recedes more than the counter electrode current collector 121. That is, as shown in Figure 13, a counter electrode active material layer 722 with a recessed end surface is formed. In other words, the counter electrode current collector 121 protrudes more than the counter electrode active material layer 722.

[0237] By performing the same process on the side surface 12, the electrode active material layer 112 recedes relative to the electrode current collector 111. That is, as shown in Figure 13, an electrode active material layer 712 with a receding end surface is formed. In other words, the electrode current collector 111 protrudes more than the electrode active material layer 712.

[0238] Furthermore, after the formation of the current collection terminals (S50), the sealing member 560 shown in Figures 10 and 11 may be formed. The sealing member 560 is formed, for example, by coating and curing a fluid resin material. Coating is carried out by methods such as inkjet printing, spray printing, screen printing, or gravure printing. Curing is carried out by drying, heating, light irradiation, etc., depending on the resin material used.

[0239] (Other embodiments) Although one or more embodiments of batteries and methods for manufacturing batteries have been described above based on embodiments, this disclosure is not limited to these embodiments. Within the scope of this disclosure, various modifications to each embodiment that a person skilled in the art could conceive, as well as forms constructed by combining components from different embodiments, are also included, as long as they do not depart from the spirit of this disclosure.

[0240] For example, while we have shown an example where both the uppermost and lowermost layers of the power generation element are counter electrode layers, at least one of the uppermost and lowermost layers may be an electrode layer. In this case, if a counter electrode current collector terminal is provided on the uppermost or lowermost electrode layer, an insulating counter electrode intermediate layer is required between it and the counter electrode current collector terminal. On the other hand, in this case, an electrode intermediate layer may not be provided between it and the electrode current collector terminal.

[0241] Furthermore, although the above embodiment shows an example where one current collector is shared between adjacent battery cells, the current collector does not necessarily have to be shared. Two counter electrode current collectors may be superimposed, or two electrode current collectors may be superimposed.

[0242] Furthermore, in the above embodiment, for example, the first side on which the counter electrode extraction section is provided and the second side on which the electrode extraction section is provided are shown to be opposite sides, but the invention is not limited to this. For example, the first side and the second side may be adjacent sides.

[0243] Furthermore, for example, the first side may be the same side as the second side. For example, if the power generation element is a rectangular parallelepiped, the power generation element has four sides. A portion of one of the four sides may be the first side, and the other regions may be the second side.

[0244] Furthermore, each of the above embodiments can be modified, replaced, added, or omitted in various ways within the scope of the claims or their equivalents. [Industrial applicability]

[0245] This disclosure can be used, for example, as a battery for electronic devices, electrical appliances, and electric vehicles. [Explanation of symbols]

[0246] 1, 201, 301, 401, 501, 601, 701, 801 batteries 10 Power generation elements 11, 12, 13, 14 Side view 15, 16 Main surface 21, 821 Electrode insulating layer 22, 822 Counter electrode insulating layer 31, 431 Counter electrode extraction section 32, 432 Electrode extraction section 41, 241, 341 Counter-pole current collector terminals 42, 242 electrode current collector terminals 51 Opposite Intermediate Layer 52, 252 electrode intermediate layer 100, 100A, 100B, 100C, 600, 700 battery cells 110, 110B, 610, 710 electrode layer 111, 611 Electrode current collector 112, 712 Electrode active material layer 120, 120C, 620, 720 counter pole layers 121, 621 Counter-pole current collector 122, 722 Counter electrode active material layer 130, 730 solid electrolyte layer 431a, 432a First conductive member 431b, 432b Second conductive member 560 Sealing member 611a, 621a, 711a, 721a protrusion

Claims

1. A power generation element having a plurality of battery cells, each containing an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, wherein the plurality of battery cells are electrically connected in parallel and stacked, On the first side surface of the power generation element, an electrode insulating member covering the electrode layer is provided, A counter electrode extraction portion that covers the first side surface and the electrode insulating member and is electrically connected to the counter electrode layer, On the second side of the power generation element, a counter electrode insulating member covering the counter electrode layer, The electrode extraction portion covers the second side surface and the counter electrode insulating member and is electrically connected to the electrode layer, The counter electrode current collector terminal connected to the counter electrode extraction section, It comprises an electrode current collector terminal connected to the electrode extraction section, The counter electrode current collector terminal and the electrode current collector terminal are provided on the same main surface of the power generation element. At least one of the first side surface and the second side surface is a flat surface. battery.

2. The system further comprises an intermediate layer disposed between at least one of the counter electrode current collector terminal and the electrode current collector terminal and the main surface. The battery according to claim 1.

3. The aforementioned intermediate layer is an insulating layer. The battery according to claim 2.

4. The heights of the counter electrode current collector terminal and the electrode current collector terminal from the main surface are the same. The battery according to claim 1.

5. One of the counter electrode current collector terminal and the electrode current collector terminal is a different member from the member constituting the main surface. The other of the counter electrode current collector terminal and the electrode current collector terminal is a member that constitutes the main surface. The battery according to claim 1.

6. The first side and the second side face away from each other, The counter electrode current collector terminal and the electrode current collector terminal are arranged in this order along the direction from the first side to the second side. The battery according to claim 1.

7. The aforementioned counter electrode layer is Counter electrode current collector and It comprises a counter electrode active material layer located between the counter electrode current collector and the solid electrolyte layer, In the first side, the counter electrode current collector protrudes more than the counter electrode active material layer. The counter electrode extraction portion is in contact with the main surface of the counter electrode current collector, The battery according to any one of claims 1 to 6.

8. In the first aspect, the counter electrode active material layer is recessed compared to the electrode layer. The battery according to claim 7.

9. The end face on the first side of the counter electrode current collector and the end face on the first side of the electrode layer coincide when viewed from a direction perpendicular to the main surface. The battery according to claim 7.

10. The electrode insulating member covers at least a portion of the solid electrolyte layer on the first side surface. The battery according to any one of claims 1 to 6.

11. The electrode insulating member covers, on the first side surface, from the electrode layer to at least a portion of the counter electrode layer. The battery according to claim 10.

12. The electrode insulating member covers the electrode layer of each of the plurality of battery cells on its first side surface. The counter electrode extraction unit is electrically connected to the counter electrode layer of each of the plurality of battery cells. The battery according to any one of claims 1 to 6.

13. The electrode insulating member has a stripe shape in a plan view of the first side surface. The battery according to any one of claims 1 to 6.

14. The electrode layer is Electrode current collector and It comprises an electrode active material layer located between the electrode current collector and the solid electrolyte layer, In the second side view, the electrode current collector protrudes more than the electrode active material layer. The electrode extraction portion is in contact with the main surface of the electrode current collector, The battery according to any one of claims 1 to 6.

15. In the second aspect, the electrode active material layer is recessed compared to the counter electrode layer. The battery according to claim 14.

16. The counter electrode insulating member covers the counter electrode layer of each of the plurality of battery cells on the second side surface. The electrode extraction section is electrically connected to the electrode layer of each of the plurality of battery cells. The battery according to any one of claims 1 to 6.

17. The aforementioned counter electrode extraction unit is, A first conductive member in contact with the counter electrode layer, A second conductive member covering the first conductive member is provided. The battery according to any one of claims 1 to 6.

18. The electrode insulating member or the counter electrode insulating member includes resin. The battery according to any one of claims 1 to 6.

19. The system further includes a sealing member that exposes at least a portion of each of the counter electrode current collector terminal and the electrode current collector terminal, and seals the power generation element, the electrode extraction portion, and the counter electrode extraction portion. The battery according to any one of claims 1 to 6.

20. The steps include preparing a plurality of battery cells, each containing an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, The steps include forming a laminate by sequentially stacking a plurality of battery cells such that the order of the electrode layer, the counter electrode layer, and the solid electrolyte layer alternates for each battery cell, The steps include cutting the laminate to flatten at least one of the first side surface and the second side surface of the laminate, The steps include covering the electrode layer with an electrode insulating member on the first side surface, and covering the counter electrode layer with a counter electrode insulating member on the second side surface, The first side surface and the electrode insulating member are covered with an electrode outlet electrically connected to the counter electrode layer, and the second side surface and the counter electrode insulating member are covered with an electrode outlet electrically connected to the electrode layer. The step includes providing a counter electrode current collector terminal connected to the counter electrode extraction portion and an electrode current collector terminal connected to the electrode extraction portion on the same main surface of the laminate, Battery manufacturing method.

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