Batteries and stacked batteries

Abstract

This battery comprising: a power generation element having at least one battery cell including an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer; a first insulating film; an electrode terminal electrically connected to the electrode layer; and a counter electrode terminal electrically connected to the counter electrode layer, wherein the power generation element has an electrode main surface which is a main surface configured of a surface of the electrode layer, a counter electrode main surface which faces the electrode main surface and is a main surface that is configured of a surface of the counter electrode layer, and a side surface which connects the electrode main surface and the counter electrode main surface, the first insulating film has a first side surface covering portion that covers the side surface, and a first main surface covering portion that is connected to the first side surface covering portion and covers the counter electrode main surface, the electrode terminal has a second side surface covering portion that covers the first side surface covering portion, and an electrode contact portion that is connected to the second side surface covering portion and is joined to the electrode main surface, the counter electrode terminal is joined to the counter electrode main surface, and the electrode terminal further has a second main surface covering portion that is connected to the second side surface covering portion and covers the first main surface covering portion.

Description

[Technical Field]

[0001] The present disclosure relates to batteries and stacked batteries. [Background technology]

[0002] In batteries, various voltages, outputs, and battery capacities are achieved by extracting current from the power generating element of the battery using lead wires and connecting the batteries in series and / or parallel. As a technology related to such battery structures and battery connections, for example, Patent Document 1 discloses an all-solid-state battery structure in which an insulating material is used on the side walls of the power generating element and current is extracted using tab leads. Furthermore, Patent Document 2 discloses a battery pack in which multiple batteries are connected with tab leads. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-335294 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-216631 Summary of the Invention [Problem to be solved by the invention]

[0004] The prior art requires highly reliable batteries. [Means for solving the problem]

[0005] A battery according to one aspect of the present disclosure includes a power generating element having at least one battery cell including an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, a first insulating film, an electrode terminal electrically connected to the electrode layer, and a counter electrode terminal electrically connected to the counter electrode layer, wherein the power generating element has an electrode principal surface which is a main surface formed by the surface of the electrode layer, a counter electrode principal surface which faces the electrode principal surface and is a main surface formed by the surface of the counter electrode layer, and a contact between the electrode principal surface and the counter electrode principal surface. the first insulating film has a first side surface covering portion covering the side surface and a first main surface covering portion connected to the first side surface covering portion and covering the counter electrode main surface; the electrode terminal has a second side surface covering portion covering the first side surface covering portion and an electrode contact portion connected to the second side surface covering portion and joined to the electrode main surface; the counter electrode terminal is joined to the counter electrode main surface, and the electrode terminal further has a second main surface covering portion connected to the second side surface covering portion and covering the first main surface covering portion.

[0006] A battery according to one aspect of the present disclosure includes a power generating element having at least one battery cell including an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, a first insulating film, a second insulating film, and an electrode terminal electrically connected to the electrode layer, wherein the power generating element has an electrode principal surface which is a main surface formed by the surface of the electrode layer, a counter electrode principal surface which faces the electrode principal surface and is a main surface formed by the surface of the counter electrode layer, and a side surface connecting the electrode principal surface and the counter electrode principal surface, and the first insulating film is formed by the side the second insulating film covers the counter electrode main surface, and an opening is formed in the second insulating film to expose a portion of the counter electrode main surface; the electrode terminal has a second side surface covering portion covering the first side surface covering portion, and an electrode contact portion connected to the second side surface covering portion and joined to the electrode main surface; and the electrode terminal further has a second main surface covering portion connected to the second side surface covering portion and covering the first main surface covering portion.

[0007] A stacked battery according to one embodiment of the present disclosure includes a first battery and one or more second batteries stacked on the first battery, the first battery being the battery described above, and the one or more second batteries being stacked on the electrode main surfaces of the first battery. [Effects of the Invention]

[0008] According to the present disclosure, a highly reliable battery or the like can be realized. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 1 of Embodiment 1. FIG. [Figure 3] FIG. 3 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 2 of Embodiment 1. In FIG. [Figure 4] FIG. 4 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 3 of Embodiment 1. In FIG. [Figure 5] FIG. 5 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 4 of Embodiment 1. In FIG. [Figure 6] FIG. 6 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 5 of Embodiment 1. In FIG. [Figure 7] FIG. 7 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 6 of Embodiment 1. In FIG. [Figure 8] FIG. 8 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a seventh modification of the first embodiment. [Figure 9A] FIG. 9A is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 8 of Embodiment 1. FIG. [Figure 9B] FIG. 9B is a cross-sectional view showing a schematic configuration of another battery according to Modification 8 of Embodiment 1. As shown in FIG. [Figure 10] FIG. 10 is a cross-sectional view showing a schematic configuration of a battery according to Modification 9 of Embodiment 1. As shown in FIG. [Figure 11] FIG. 11 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to the second embodiment. [Figure 12] FIG. 12 is a cross-sectional view showing a schematic configuration of another battery according to the second embodiment. [Figure 13] FIG. 13 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Summary of the Disclosure) A battery according to an embodiment of the present disclosure includes a power generating element having at least one battery cell including an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, a first insulating film, an electrode terminal electrically connected to the electrode layer, and a counter electrode terminal electrically connected to the counter electrode layer, and the power generating element includes an electrode main surface which is a main surface formed by the surface of the electrode layer, a counter electrode main surface which faces the electrode main surface and is a main surface formed by the surface of the counter electrode layer, and a contact between the electrode main surface and the counter electrode main surface. the first insulating film has a first side surface covering portion covering the side surface and a first main surface covering portion connected to the first side surface covering portion and covering the counter electrode main surface; the electrode terminal has a second side surface covering portion covering the first side surface covering portion and an electrode contact portion connected to the second side surface covering portion and joined to the electrode main surface; the counter electrode terminal is joined to the counter electrode main surface, and the electrode terminal further has a second main surface covering portion connected to the second side surface covering portion and covering the first main surface covering portion.

[0011] This configuration allows for a highly reliable battery, even when the battery is thinned and / or enlarged. Conventional connection structures that use lead wire terminals to extract current have drawbacks, such as the risk of short circuits and vulnerability to deformation due to impact. These problems become even more pronounced when the battery is made smaller, thinner, larger, or multilayered. Furthermore, because the electrode terminal wraps around to cover the counter electrode principal surface, the first insulating film can be sandwiched and covered from the outside. Furthermore, both the electrode terminal and the counter electrode terminal can be bonded to a substrate or the like on the counter electrode principal surface side of the power generating element.

[0012] According to the battery configuration of this aspect, the electrode terminal and the counter electrode terminal are bonded to the power generating element, which has each layer restrained from the side of the power generating element by the first insulating film. This allows for miniaturization, and the power generating element, the first insulating film, and each terminal are integrated, making short circuits and damage to the terminals less likely to occur compared to when lead wires are drawn out. Furthermore, the counter electrode terminal bonded to the counter electrode main surface can be bonded to a substrate or the like. Therefore, bonding to a substrate or the like can improve the battery's resistance to bending. This results in a highly reliable battery.

[0013] Furthermore, for example, the counter electrode terminal may be plate-shaped and may entirely overlap the counter electrode main surface in a plan view.

[0014] This structure prevents the counter electrode terminal from protruding from the counter electrode main surface in a plan view, allowing for a more compact battery. Furthermore, the plate-shaped counter electrode terminal allows the electrode terminal and the counter electrode main surface to be bonded over a wide area, ensuring a strong bond even when the battery is mounted on a substrate. Furthermore, the resistance of the counter electrode terminal, which serves as a conductive path when bonded to the substrate, is reduced, reducing localized heat generation.

[0015] Furthermore, for example, the battery may include a plurality of counter electrode terminals.

[0016] This can further improve the durability to bending stress and thermal cycles when a battery is mounted on the substrate. Furthermore, when the counter electrode terminal is enlarged, defects due to residual air, solvent, binder, etc. when forming the counter electrode terminal can be reduced by dividing the counter electrode terminal.

[0017] Furthermore, for example, at least one of the electrode terminal and the counter electrode terminal may contain a conductive resin.

[0018] This allows the buffering properties of the conductive resin to absorb stress on the power generating element, and also prevents deformation when the electrode terminal and counter electrode terminal are joined to the mounting substrate, absorbing bending stress and thermal shocks such as those caused by thermal cycling, thereby improving the durability of the battery.

[0019] Furthermore, for example, the device may further include an electrode solder layer that covers the electrode terminal and contains solder as a main component, and a counter electrode solder layer that covers the counter electrode terminal and contains solder as a main component.

[0020] This allows the battery to be soldered to the substrate when mounted on the board, providing high adhesion and enabling the battery to be joined to the board with good productivity in mass production processes such as reflow mounting.

[0021] Furthermore, for example, the electrode solder layer and the counter electrode solder layer may each be made of a solder plating film.

[0022] As a result, for example, when the terminals contain metal components such as silver particles contained in the conductive resin, the solder plating film can suppress the movement of the metal components, which tend to migrate, thereby improving the reliability of the battery.

[0023] Furthermore, for example, the solder plating film may include a nickel plating base film and a tin plating film formed on the nickel plating base film.

[0024] This nickel-plated undercoat prevents migration of metal components such as silver particles in the conductive resin. The tin-plated surface layer also improves solder wettability at the joint with the substrate, improving adhesion of the battery to the substrate. This, in turn, improves the reliability of the battery.

[0025] Furthermore, for example, the power generating element may further include a substrate disposed opposite the power generating element, the counter electrode terminal being located between the substrate and the counter electrode layer, and the substrate having an electrode connection part joined to the electrode terminal and electrically connected to the electrode layer, and a counter electrode connection part joined to the counter electrode terminal and electrically connected to the counter electrode layer.

[0026] This allows the power generating element to be bonded to the substrate, improving the battery's resistance to bending.

[0027] Furthermore, for example, the counter electrode may further include a second insulating film covering a part of the counter electrode main surface, and the second insulating film may cover the outer periphery of the counter electrode terminal in a plan view.

[0028] As a result, the outer periphery of the counter electrode terminal, which is the starting point for peeling of the counter electrode terminal due to flexural deformation of the power-generating element, can be protected by the second insulating film, thereby suppressing peeling of the counter electrode terminal. This improves the adhesion of the counter electrode terminal to the power-generating element and further improves the battery's resistance to flexing. Furthermore, even if local stress acts on the outer periphery of the counter electrode terminal, the stress can be dispersed to the second insulating film. Furthermore, since the outer periphery of the counter electrode terminal is covered by the second insulating film, the isolation between the counter electrode terminal and the electrode terminal is improved.

[0029] Furthermore, for example, an outer peripheral edge portion of the counter electrode terminal in plan view may be sandwiched between the counter electrode main surface and the second insulating film.

[0030] As a result, the outer peripheral edge of the counter electrode terminal is covered with the second insulating film from the side opposite to the counter electrode main surface, which prevents the counter electrode terminal from peeling off from the outer periphery due to flexural deformation and improves adhesion to the power generating element, thereby improving the flexural resistance of the battery.

[0031] A battery according to an aspect of the present disclosure includes a power generating element having at least one battery cell including an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer, a first insulating film, a second insulating film, and an electrode terminal electrically connected to the electrode layer, wherein the power generating element has an electrode principal surface which is a main surface formed by the surface of the electrode layer, a counter electrode principal surface which faces the electrode principal surface and is a main surface formed by the surface of the counter electrode layer, and a side surface connecting the electrode principal surface and the counter electrode principal surface, and the first insulating film is the electrode terminal has a second side surface covering portion that covers the first side surface covering portion and a first main surface covering portion that is connected to the first side surface covering portion and covers the counter electrode main surface, the second insulating film covers the counter electrode main surface and an opening that exposes a part of the counter electrode main surface is formed in the second insulating film, the electrode terminal has a second side surface covering portion that covers the first side surface covering portion and an electrode contact portion that is connected to the second side surface covering portion and joined to the electrode main surface, and the electrode terminal further has a second main surface covering portion that is connected to the second side surface covering portion and covers the first main surface covering portion.

[0032] As a result, the electrode terminal is bonded to the power generating element, whose layers are bound by the first insulating film from the side of the power generating element, making it possible to reduce the size. Furthermore, the power generating element, the first insulating film, and the electrode terminal are integrated, making short circuits and damage to the terminal less likely to occur compared to when lead wires are drawn out. Furthermore, the battery can be bonded to a substrate or the like at the location exposed by the opening in the second insulating film. Therefore, bonding to a substrate or the like improves the battery's resistance to flexing. Furthermore, the electrode terminal wraps around to cover the counter electrode main surface, so that the first insulating film can be sandwiched and covered from the outside. Furthermore, both the electrode terminal and the counter electrode terminal can be bonded to a substrate or the like on the counter electrode main surface side of the power generating element. This results in a highly reliable battery.

[0033] Furthermore, for example, the power generating element may further include a substrate disposed opposite the power generating element, the second insulating film being located between the substrate and the counter electrode layer, and the substrate may have an electrode connecting portion joined to the electrode terminal and electrically connected to the electrode layer, and a counter electrode connecting portion joined to a portion of the counter electrode main surface exposed by the opening and electrically connected to the counter electrode layer.

[0034] This allows the power generating element to be bonded to the substrate, improving the battery's resistance to bending.

[0035] Furthermore, for example, the first insulating film and the second insulating film may be connected to each other.

[0036] This allows the first insulating film and the second insulating film to form a continuous coating film, which further enhances the reinforcement and improves the flexural strength of the battery, thereby improving the battery's resistance to bending.

[0037] Furthermore, for example, the second insulating film may include a resin.

[0038] This allows the buffering properties of the resin to absorb stresses caused by differences in the thermal expansion coefficients between the power-generating element and the counter electrode terminal, preventing the counter electrode terminal from peeling off. Furthermore, the resin also functions as a protective layer that covers the main surface of the counter electrode and provides a buffering function, reducing the occurrence of damage and scratches to the power-generating element during handling.

[0039] Furthermore, for example, in a plan view, the length of the electrode contact portion from the side surface may be longer than the length of the second principal surface covering portion from the side surface.

[0040] This increases the bonding area between the electrode contact portion and the electrode main surface, thereby enabling the electrode terminal and the electrode main surface to be firmly bonded together and reducing the resistance at the bonding portion between the electrode terminal and the electrode main surface.

[0041] Furthermore, for example, the first insulating film may cover the end of the electrode terminal.

[0042] This makes it possible to prevent the electrode terminals from peeling off from the ends of the electrode terminals due to stress caused by bending and thermal shock during solder mounting.

[0043] Furthermore, for example, the side surface may include a first side surface and a second side surface facing the first side surface, and the first insulating film may cover the first side surface and the second side surface.

[0044] This allows the first insulating film to sandwich and bind the layers in the power generating element from the opposing side surfaces, effectively preventing the layers from peeling off, improving the reliability of the battery.

[0045] Furthermore, for example, the first insulating film may include a resin.

[0046] As a result, when stress occurs in the electrode terminals due to bending or expansion and contraction during charge and discharge cycles, the stress can be absorbed by the cushioning properties of the resin, which prevents peeling and cracking of the electrode terminals and improves the reliability of the battery.

[0047] Furthermore, for example, the at least one battery cell may be a plurality of battery cells, and the plurality of battery cells may be electrically connected in series and stacked.

[0048] This allows for a high voltage to be achieved, resulting in a highly reliable, high-energy battery.

[0049] Furthermore, for example, the solid electrolyte layer may contain a solid electrolyte having lithium ion conductivity.

[0050] This makes it possible to realize a highly reliable lithium ion battery containing a solid electrolyte.

[0051] Also, for example, the battery may include one first battery and one or more second batteries stacked on the first battery, the first battery being the above-mentioned battery, and the one or more second batteries being stacked on the electrode main surface of the first battery.

[0052] As a result, since the above battery is included as the first battery, the reliability of the high voltage and / or large capacity stacked battery can be improved.

[0053] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0054] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in the independent claims are described as optional components.

[0055] Furthermore, in this specification, terms indicating the relationship between elements, such as parallelism, terms indicating the shape of elements, such as rectangle, and numerical ranges are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0056] In addition, the drawings are not necessarily strict illustrations, and the same reference numerals are used to designate substantially the same components in the drawings, and redundant explanations are omitted or simplified.

[0057] In this specification and drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional Cartesian coordinate system. In each embodiment, the z-axis direction is the thickness direction of the battery. In this specification, the "thickness direction" refers to the direction perpendicular to the plane on which each layer is stacked.

[0058] In addition, in this specification, "plan view" means a view of the battery in the stacking direction of the battery, and "thickness" in this specification means the length of the battery and each layer in the stacking direction. In other words, the direction in which each layer is stacked is the thickness direction of each layer.

[0059] In addition, in this specification, the terms "inside" and "outside" refer to the inside and outside of the battery when the center side is the inside.

[0060] Furthermore, in this specification, the terms "upper" and "lower" in the battery configuration do not refer to the upper direction (vertically upper) and lower direction (vertically lower) in absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in the stacking configuration. Furthermore, the terms "upper" and "lower" are applied not only to a case where two components are arranged with a gap between them and another component exists between the two components, but also to a case where two components are arranged closely together and the two components are in contact with each other.

[0061] (Embodiment 1) First, the battery according to the first embodiment will be described.

[0062] Fig. 1 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to the present embodiment. Specifically, Fig. 1(a) is a cross-sectional view of a battery 100 according to the present embodiment, and Fig. 1(b) is a plan view of the battery 100 as seen from below in the z-axis direction. Fig. 1(a) shows a cross section taken along line Ia-Ia in Fig. 1(b).

[0063] As shown in FIG. 1 , the battery 100 has a thin rectangular parallelepiped structure. The battery 100 includes a power generating element 1 having at least one battery cell 50 including an electrode layer 10, a counter electrode layer 20, and a solid electrolyte layer 30, a first insulating film 70, an electrode terminal 80, and a counter electrode terminal 90. The battery 100 is, for example, an all-solid-state battery. The battery 100 is used, for example, mounted on a substrate. When the battery 100 is mounted on a substrate, for example, the electrode terminal 80 and the counter electrode terminal 90 of the battery 100 are joined to conductive connections such as wiring on the substrate. In this way, the battery 100 can be mounted on a rigid substrate, thereby improving the flex resistance of the battery 100.

[0064] In this embodiment, the power generating element 1 is composed of one battery cell 50. The shape of the power generating element 1 is, for example, a rectangular parallelepiped. The shape of the power generating element 1 is not limited to a rectangular parallelepiped, and may be other shapes such as a cylindrical or polygonal prism. The power generating element 1 has an electrode principal surface 2 which is a main surface formed by the surface of the electrode layer 10, a counter electrode principal surface 3 which is a main surface opposite to the electrode principal surface 2 and formed by the surface of the counter electrode layer 20, and a side surface connecting the electrode principal surface 2 and the counter electrode principal surface 3. In this embodiment, the side surface of the power generating element 1 is composed of four surfaces, which are two pairs of opposing surfaces, and includes a first side surface 6 and a second side surface 7 which are surfaces on the shorter sides of the power generating element 1 in a plan view.

[0065] The electrode principal surface 2 and the counter electrode principal surface 3 are surfaces perpendicular to the stacking direction in the power generating element 1. The electrode principal surface 2 is formed by the principal surface of the electrode layer 10 opposite to the solid electrolyte layer 30 side. The counter electrode principal surface 3 is formed by the principal surface of the counter electrode layer 20 opposite to the solid electrolyte layer 30 side.

[0066] The first side surface 6 and the second side surface 7 extend from the ends of the electrode principal surface 2 and the counter electrode principal surface 3 in a direction intersecting the electrode principal surface 2 and the counter electrode principal surface 3, and are surfaces that connect the electrode principal surface 2 and the counter electrode principal surface 3. In this embodiment, the first side surface 6 and the second side surface 7 are surfaces parallel to the stacking direction of the power generating element 1. The first side surface 6 and the second side surface 7 are positioned opposite each other. Furthermore, the first side surface 6 and the second side surface 7 are parallel to each other.

[0067] At least a portion of the main surface and side surface of the power generating element 1 may be processed to have an uneven, rough surface to improve adhesion with the first insulating film 70. For example, at least a portion of the main surface and side surface of the power generating element 1 may be polished with abrasive paper of #800 to #1000 to have an uneven, rough surface, and then the first insulating film 70 may be applied. In this case, the surface roughness may be, for example, a maximum height Rz of 10 μm to 20 μm. This allows the surface energy of the power generating element 1 to be dispersed, reducing the effects of surface tension, improving wettability during application of the first insulating film 70 and increasing shape accuracy. This improves the positional accuracy between the first insulating film 70 and the electrode terminals 80 formed on the first insulating film 70, thereby suppressing short circuits. Furthermore, the increased surface roughness increases the surface area of ​​the power generating element 1, which improves adhesion between the surface of the power generating element 1 and the first insulating film 70.

[0068] The battery cell 50 includes an electrode layer 10, a counter electrode layer 20, and a solid electrolyte layer 30 located between the electrode layer 10 and the counter electrode layer 20. The electrode layer 10 includes an electrode current collector 11 and an electrode active material layer 12 located between the electrode current collector 11 and the solid electrolyte layer 30. The counter electrode layer 20 includes a counter electrode current collector 21 and a counter electrode active material layer 22 located between the counter electrode current collector 21 and the solid electrolyte layer 30. In other words, the battery cell 50 includes the electrode current collector 11, the electrode active material layer 12 arranged in contact with the electrode current collector 11, the counter electrode current collector 21, the counter electrode active material layer 22 arranged in contact with the counter electrode current collector 21, and the solid electrolyte layer 30 located between the electrode active material layer 12 and the counter electrode active material layer 22 and including a solid electrolyte. The electrode active material layer 12 and the counter electrode active material layer 22 are disposed between the electrode current collector 11 and the counter electrode current collector 21. The battery cell 50 has a structure in which the electrode layer 10, the solid electrolyte layer 30, and the counter electrode layer 20 are stacked in this order. More specifically, the battery cell 50 has a structure in which the electrode current collector 11, the electrode active material layer 12, the solid electrolyte layer 30, the counter electrode active material layer 22, and the counter electrode current collector 21 are stacked in this order.

[0069] The electrode current collector 11, the electrode active material layer 12, the solid electrolyte layer 30, the counter electrode active material layer 22, and the counter electrode current collector 21 are each rectangular in plan view. The shapes of the electrode current collector 11, the electrode active material layer 12, the solid electrolyte layer 30, the counter electrode active material layer 22, and the counter electrode current collector 21 in plan view are not particularly limited, and may be shapes other than rectangular, such as circular, elliptical, or polygonal.

[0070] The electrode current collector 11, the electrode active material layer 12, the solid electrolyte layer 30, the counter electrode active material layer 22, and the counter electrode current collector 21 have the same shape, position, and size in a planar view. The electrode current collector 11, the electrode active material layer 12, the solid electrolyte layer 30, the counter electrode active material layer 22, and the counter electrode current collector 21 may have different shapes, positions, and sizes in a planar view. For example, the counter electrode active material layer 22 may be larger than the electrode active material layer 12 in a planar view. Furthermore, the solid electrolyte layer 30 may be larger than the electrode active material layer 12 and the counter electrode active material layer 22, cover the side surfaces of the electrode active material layer 12 and the counter electrode active material layer 22, and be in contact with the electrode current collector 11 and the electrode active material layer 12.

[0071] In this embodiment, the main surface of the electrode current collector 11 opposite to the electrode active material layer 12 side constitutes the electrode main surface 2.

[0072] The electrode active material layer 12 is laminated in contact with one main surface of the electrode current collector 11. Note that another layer, such as a bonding layer made of a conductive material, may be provided between the electrode current collector 11 and the electrode active material layer 12. The electrode layer 10 does not need to include the electrode current collector 11. For example, a current collector of another electrode layer 10 or counter electrode layer 20, a terminal for extraction, or a connection layer with another battery may function as a current collector for the electrode active material layer 12. In other words, the electrode layer 10 may include only the electrode active material layer 12 of the electrode current collector 11 and the electrode active material layer 12.

[0073] In this embodiment, the main surface of counter electrode current collector 21 opposite to counter electrode active material layer 22 constitutes counter electrode main surface 3.

[0074] Furthermore, the counter electrode active material layer 22 is laminated in contact with one main surface of the counter electrode current collector 21. Note that another layer, such as a bonding layer made of a conductive material, may be provided between the counter electrode current collector 21 and the counter electrode active material layer 22. Furthermore, the counter electrode layer 20 does not need to include the counter electrode current collector 21, and for example, the counter electrode terminal 90 or the like may function as a current collector for the counter electrode active material layer 22. In other words, of the counter electrode current collector 21 and the counter electrode active material layer 22, the counter electrode layer 20 may include only the counter electrode active material layer 22.

[0075] In the present disclosure, one of the electrode layer 10 and the counter electrode layer 20 is, for example, a positive electrode layer having a positive electrode active material layer and a positive electrode current collector as the electrode active material layer 12 and the electrode current collector 11, and the other is a negative electrode layer having a negative electrode active material layer and a negative electrode current collector as the counter electrode active material layer 22 and the counter electrode current collector 21. Hereinafter, the positive electrode active material layer and the negative electrode active material layer may be collectively referred to simply as "active material layer." Furthermore, the positive electrode current collector and the negative electrode current collector may be collectively referred to simply as "current collector."

[0076] The current collector may be made of any conductive material, and the material is not particularly limited. For example, a foil, plate, or mesh-like material made of stainless steel, nickel, aluminum, iron, titanium, copper, palladium, gold, platinum, or an alloy of two or more of these metals may be used. The current collector material may be appropriately selected taking into consideration the manufacturing process, the operating temperature, and the operating pressure, and the battery operating potential and conductivity applied to the current collector. The current collector material may also be selected according to the required tensile strength and heat resistance. For example, the current collector may be a high-strength electrolytic copper foil or a clad material in which different metal foils are laminated.

[0077] The thickness of the current collector is, for example, in the range of 10 μm to 100 μm, but even if it is less than 10 μm, it is set within a range that satisfies characteristics such as handling during the manufacturing process, current flow, and reliability.

[0078] The positive electrode active material layer contains at least a positive electrode active material. The positive electrode active material layer is mainly a layer composed of a positive electrode material such as a positive electrode active material. The positive electrode active material is a substance in which metal ions such as lithium (Li) ions or magnesium (Mg) ions are inserted into or detached from the crystal structure at a potential higher than that of the negative electrode, and oxidation or reduction occurs accordingly. The type of the positive electrode active material can be appropriately selected according to the type of the battery, and known positive electrode active materials can be used.

[0079] Examples of the positive electrode active material include compounds containing lithium and transition metal elements. More specifically, oxides containing lithium and transition metal elements, and phosphate compounds containing lithium and transition metal elements can be mentioned. Examples of the oxide containing lithium and transition metal elements include, for example, LiNi x M 1-x O2 (where M is at least one element among Co, Al, Mn, V, Cr, Mg, Ca, Ti, Zr, Nb, Mo, and W, and x is 0 < x ≤ 1), such as lithium nickel composite oxides, layered oxides such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), and lithium manganate (LiMn2O4), and lithium manganate (LiMn2O4, Li2MnO3, LiMnO2) having a spinel structure are used. Examples of the phosphate compound containing lithium and transition metal elements include, for example, lithium iron phosphate (LiFePO4) having an olivine structure. In addition, sulfides such as sulfur (S) and lithium sulfide (Li2S) can also be used as the positive electrode active material. In that case, a material in which lithium niobate (LiNbO3) or the like is coated on or added to the positive electrode active material particles can be used as the positive electrode active material. Note that only one of these materials may be used as the positive electrode active material, or two or more of these materials may be combined and used.

[0080] As described above, the positive electrode active material layer may contain at least a positive electrode active material. The positive electrode active material layer may be a mixture layer composed of a mixture of a positive electrode active material and other additive materials. Examples of other additive materials include solid electrolytes such as inorganic solid electrolytes or sulfide-based solid electrolytes, conductive additives such as acetylene black, and adhesive binders such as polyethylene oxide or polyvinylidene fluoride. By mixing the positive electrode active material with other additive materials, such as a solid electrolyte, in a predetermined ratio, the positive electrode active material layer can improve both lithium ion conductivity and electronic conductivity within the positive electrode active material layer. Examples of solid electrolytes that can be used include those exemplified as the solid electrolyte of the solid electrolyte layer 30 described below.

[0081] The thickness of the positive electrode active material layer is, for example, 5 μm or more and 300 μm or less.

[0082] The negative electrode active material layer contains at least a negative electrode active material. The negative electrode active material layer is a layer mainly composed of a negative electrode material such as a negative electrode active material. The negative electrode active material is a material in which metal ions such as lithium (Li) ions or magnesium (Mg) ions are inserted or extracted into or from the crystal structure at a potential lower than that of the positive electrode, and oxidation or reduction occurs accordingly. The type of negative electrode active material can be appropriately selected depending on the type of battery, and known negative electrode active materials can be used.

[0083] Examples of the negative electrode active material include carbon materials such as natural graphite, artificial graphite, graphite carbon fiber, and resin-baked carbon, as well as alloy materials that are mixed with a solid electrolyte. Examples of alloy materials include LiAl, LiZn, LiBi, LiCd, LiSb, LiSi, and Li. 4.4 Pb, Li 4.4 Sn, Li 0.17 C, lithium alloys such as LiC6, lithium titanate (Li4Ti5O 12 ), oxides of lithium and transition metal elements such as zinc oxide (ZnO) and silicon oxide (SiO x) and other metal oxides can be used. The negative electrode active material may be made of only one of these materials, or a combination of two or more of these materials.

[0084] As described above, the negative electrode active material layer may contain at least a negative electrode active material. The negative electrode active material layer may be a mixture layer composed of a mixture of a negative electrode active material and other additive materials. Examples of other additive materials include solid electrolytes such as inorganic solid electrolytes or sulfide-based solid electrolytes, conductive additives such as acetylene black, and adhesive binders such as polyethylene oxide or polyvinylidene fluoride. By mixing the negative electrode active material with other additive materials, such as a solid electrolyte, in a predetermined ratio, the negative electrode active material layer can improve both lithium ion conductivity and electronic conductivity. Examples of solid electrolytes that can be used include those exemplified as the solid electrolyte of the solid electrolyte layer 30 described below.

[0085] The thickness of the negative electrode active material layer is, for example, 5 μm or more and 300 μm or less.

[0086] The solid electrolyte layer 30 is disposed between the electrode active material layer 12 and the counter electrode active material layer 22 and is in contact with the electrode active material layer 12 and the counter electrode active material layer 22 .

[0087] The solid electrolyte layer 30 includes at least a solid electrolyte. The solid electrolyte layer 30 includes, for example, a solid electrolyte as a main component. The solid electrolyte may be any known solid electrolyte for batteries that does not have electronic conductivity but has ionic conductivity. For example, a solid electrolyte that conducts metal ions such as lithium ions or magnesium ions may be used. The type of solid electrolyte may be selected appropriately depending on the type of conductive ions. For example, an inorganic solid electrolyte such as a sulfide-based solid electrolyte or an oxide-based solid electrolyte may be used. For example, a lithium-containing sulfide such as a Li2S-P2S5-based, Li2S-SiS2-based, Li2S-B2S3-based, Li2S-GeS2-based, Li2S-SiS2-LiI-based, Li2S-SiS2-Li3PO4-based, Li2S-Ge2S2-based, Li2S-GeS2-P2S5-based, or Li2S-GeS2-ZnS-based solid electrolyte may be used as the sulfide-based solid electrolyte. Examples of oxide-based solid electrolytes include lithium-containing metal oxides such as Li2O-SiO2 and Li2O-SiO2-P2O5; x P y O 1-z N z Lithium-containing metal nitrides such as lithium phosphate (LiPO), lithium-containing transition metal oxides such as lithium titanium oxide, etc. As the solid electrolyte, only one of these materials may be used, or two or more of these materials may be used in combination.

[0088] In addition to the solid electrolyte, the solid electrolyte layer 30 may contain an adhesive binder such as polyethylene oxide or polyvinylidene fluoride.

[0089] The thickness of the solid electrolyte layer 30 is, for example, not less than 5 μm and not more than 150 μm.

[0090] The solid electrolyte material may be composed of an aggregate of particles or a sintered structure.

[0091] As described above, the battery 100 includes a first insulating film 70, an electrode terminal 80, and a counter electrode terminal 90. In the example shown in FIG. 1 , two first insulating films 70 and two electrode terminals 80 are provided along two opposing sides of the power generating element 1 in a planar view, i.e., along the first side surface 6 and the second side surface 7. The first insulating films 70 cover the first side surface 6 and the second side surface 7, which are both short side surfaces of the power generating element 1 in a planar view. That is, one of the two first insulating films 70 covers the first side surface 6, and the other covers the second side surface 7. The two electrode terminals 80 are in contact with the two first insulating films 70 arranged opposite each other. In this way, by covering the first side surface 6 and the second side surface 7, which are both ends of the power generating element 1 in a planar view, with the first insulating film 70, the layers in the power generating element 1 can be bound from both ends in a planar view, effectively suppressing peeling of the layers.

[0092] The following mainly describes the first insulating film 70 and the electrode terminal 80 provided along the first side surface 6, out of the two first insulating films 70 and the two electrode terminals 80. The first insulating film 70 and the electrode terminal 80 provided along the second side surface 7 have the same configuration as the first insulating film 70 and the electrode terminal 80 provided along the first side surface 6, and the same description applies thereto.

[0093] When the power generating element 1 has four side surfaces, as in the battery 100, the first insulating film 70 only needs to cover at least one of the side surfaces. For example, the first insulating film 70 may cover adjacent sides of the side surfaces of the power generating element 1, rather than the opposing sides. Furthermore, the first insulating film 70 may cover all of the side surfaces of the power generating element 1. Furthermore, the number of first insulating films 70 is not particularly limited, and it is sufficient that the side surfaces of the power generating element 1 are covered by one or more first insulating films 70.

[0094] The first insulating film 70 has a first side surface covering portion 71 that covers the side surface of the power generating element 1, and a first main surface covering portion 72 that covers the counter electrode main surface 3. In this embodiment, the first insulating film 70 does not cover the electrode main surface 2. This makes it easier to connect the electrode terminal 80 to the electrode layer 10. The first insulating film 70 may cover a portion of the electrode main surface 2.

[0095] The first side surface covering portion 71 is, for example, in contact with the first side surface 6 to cover the first side surface 6 and is joined to the first side surface 6. The first side surface covering portion 71 continuously covers, for example, the first side surface 6 from the end of the first side surface 6 on the electrode principal surface 2 side to the end of the first side surface 6 on the counter electrode principal surface 3 side. In the example shown in FIG. 1 , the first side surface covering portion 71 covers the entire first side surface 6. The first side surface covering portion 71 also covers a portion of the side surface on the long side of the power generating element 1 in a plan view (i.e., the XZ plane of the power generating element 1), which is a surface adjacent to the first side surface 6. The first side surface covering portion 71 may cover the entire side surface on the long side of the power generating element 1 in a plan view. The first side surface covering portion 71 may also cover a portion of the electrode principal surface 2.

[0096] The first main surface covering portion 72 is in contact with, for example, the counter electrode main surface 3 and is bonded to the counter electrode main surface 3. The first main surface covering portion 72 covers the end portion of the counter electrode main surface 3. The first main surface covering portion 72 covers, for example, the surface of the counter electrode current collector 21.

[0097] The first side surface covering portion 71 and the first main surface covering portion 72 are continuous and connected. That is, the first insulating film 70 extends from the first side surface 6 onto the counter electrode main surface 3 which is formed by the main surface of the counter electrode current collector 21, and continuously covers the ridge line between the first side surface 6 and the counter electrode main surface 3.

[0098] As described above, in this embodiment, the first insulating film 70 also covers part of the side surface end portions of the long sides of the power-generating element 1 in a plan view, continuously from the corners and ridges located at the ends of the first side surface 6 and the second side surface 7 of the power-generating element 1. This configuration of the first insulating film 70 covering the corners and ridges provides the effect of more firmly protecting the power-generating element 1 while also fixing the corners of the power-generating element 1, which are prone to peeling, and further improves the reliability of the battery 100.

[0099] The first insulating film 70 may be any material as long as it is an electrical insulator. The first insulating film 70 includes, for example, a resin. The first insulating film 70 includes, for example, an insulating resin as a main component. Examples of resins include epoxy resins, acrylic resins, polyimide resins, and silsesquioxane. Specifically, the first insulating film 70 includes, for example, a coatable thermosetting resin, such as a liquid or powder thermosetting epoxy resin. By applying such a coatable thermosetting resin in liquid or powder form to the side surfaces and main surfaces of the power generating element 1 and thermally curing it, the side surfaces and main surfaces of the power generating element 1 can be covered with the first insulating film 70, bonded, and fixed. The first insulating film 70 may also have a stacked structure of multiple insulating layers made of the same or different materials.

[0100] The first insulating film 70 may be made of a material softer than the components of the power generating element 1 (e.g., the current collector, the active material, and the solid electrolyte). The Young's modulus of the first insulating film 70 is, for example, 10 GPa or more and 40 GPa or less. Specifically, the first insulating film 70 may be made of an epoxy resin having a Young's modulus in this range. This allows the first insulating film 70 to absorb impacts on the areas covered with the first insulating film 70 and protect the battery 100. Furthermore, even in a thermal cycle environment, the relatively soft first insulating film 70 absorbs stress acting on the interface between the first insulating film 70 and the side surface of the power generating element 1, etc., due to the difference in the thermal expansion coefficients between the first insulating film 70 and the power generating element 1. This prevents adverse effects on the structure of each component of the battery 100, such as cracking or peeling.

[0101] The softness of the constituent material of the power generating element 1 and the first insulating film 70 (for example, elastic modulus such as Young's modulus) can be measured by applying a rigid indenter in the same manner as in measuring Vickers hardness, and by comparing the size of the traces, the relative softness of the constituent material of the power generating element 1 and the first insulating film 70 can be compared. For example, when the indenter is pressed with the same force against each part of the cross section of the power generating element 1, if the first insulating film 70 is in a state where it is more deeply depressed than the constituent material of the power generating element 1, it can be determined that the first insulating film 70 is softer than the constituent material of the power generating element 1.

[0102] Furthermore, in terms of alleviating stress on the power generating element 1 caused by expansion or contraction due to temperature changes, easing thermal stress, and ensuring reliability of bonding with the side walls, the first insulating film 70 may be made of a material that is softer than the current collector and contains various resin materials.

[0103] For example, the Young's modulus of the first insulating film 70 is lower than the Young's modulus of the metals constituting the electrode current collector 11 and the counter electrode current collector 21. As a result, the stress on the power generating element 1 caused by temperature changes of the current collectors is alleviated by deformation of the first insulating film 70.

[0104] Furthermore, from the viewpoint of alleviating stress on the power generating element 1 caused by expansion or contraction of the solid electrolyte layer 30 due to temperature changes and repeated charging and discharging, and improving the reliability of the battery 100, the Young's modulus of the first insulating film 70 may be lower than the Young's modulus of the solid electrolyte layer 30.

[0105] Furthermore, from the viewpoint of alleviating stress on the power generating element 1 caused by expansion or contraction of the electrode active material layer 12 and the counter electrode active material layer 22 due to temperature changes and improving the reliability of the battery 100, the Young's modulus of the first insulating film 70 may be lower than the Young's modulus of the electrode active material layer 12 and the counter electrode active material layer 22. The relative relationship between these Young's moduli can be compared, for example, from the displacement characteristics with respect to pressure when a probe is pressed into them, the size relationship of the depressions, or the like.

[0106] The two first insulating films 70 may be made of the same material or different materials. When the two first insulating films 70 are made of different materials, at least one of the two first insulating films 70 may satisfy the material, physical properties, etc. of the insulating film described above.

[0107] The thickness of the first insulating film 70 may be uniform or non-uniform. From the viewpoint of electrical insulation, the thickness of the thinnest portion of the first insulating film 70 may be 10 μm or more. From the viewpoint of shock absorption, the thickness of the thinnest portion of the first insulating film 70 may be 100 μm or more. From the viewpoint of blocking air and moisture, the thickness of the thinnest portion of the first insulating film 70 may be 1 mm or more. There is no particular upper limit to the thickness of the first insulating film 70. The thickness of the first insulating film 70 may be set to an appropriate thickness that satisfies both the weight energy density and volume energy density of the battery 100 and the protective effect of the first insulating film 70. From the viewpoint of reducing the thickness of the battery 100, which has a large effect on the volume energy density, and protecting the side surfaces of the power generating element 1, which are easily damaged by impact, the thickness of the first main surface covering portion 72 may be smaller than the thickness of the first side surface covering portion 71.

[0108] The first insulating film 70 may have a laminated structure of multiple insulating layers. The laminated structure of multiple insulating layers is formed, for example, by applying and curing an insulating resin, such as an epoxy resin, multiple times. For example, by applying and curing an additional epoxy resin on top of a cured epoxy resin, defects such as voids and thin areas due to thickness variations can be reduced, resulting in a dense and strong first insulating film 70. Forming the electrode terminal 80 on a first insulating film 70 with reduced defects reduces the problem of conductive material penetrating the first insulating film 70 and causing a short circuit. Furthermore, if a thick first insulating film 70 is formed by applying and curing an insulating resin all at once, there is a risk of peeling due to stress during curing. In particular, if a bent portion exists between the first side surface covering portion 71 and the first main surface covering portion 72, contraction stress during resin curing acts on the end opposite the bent portion, easily leading to peeling in the form of peeling from the end. Therefore, if thin insulating layers are applied and cured multiple times to form a laminate, even if the first insulating film 70 is formed to a thickness of, for example, 100 μm, strong curing stress is unlikely to act, and peeling is suppressed. This makes it possible to form a first insulating film 70 with a laminated structure of multiple insulating layers while suppressing cracking and peeling. Of course, it is also possible to form a first insulating film 70 with a thickness of 1 mm. This type of laminated structure of multiple insulating layers can be observed as a laminated structure that has been repeatedly applied and cured multiple times by general observation of a polished cross section using an optical microscope or a scanning electron microscope (SEM).

[0109] The number of insulating layers included in the first insulating film 70 is not particularly limited, and may be two or more, or may be three or more.

[0110] The thickness of each of the plurality of insulating layers is, for example, 30 μm or less. From the viewpoint of forming a denser first insulating film 70, the thickness of each of the plurality of insulating layers may be 10 μm or less.

[0111] The insulating layers constituting the multiple insulating layers may be composed of the same material or different materials. In other words, when forming insulating layers multiple times, different insulating materials may be used for each layer. For example, by repeatedly applying and curing insulating resins so that their curing temperatures, melting points, or glass transition points decrease from high to low, a dense and thick first insulating film 70 can be formed without degrading the properties of the previously formed insulating layers due to the heat during curing. In this case, the outermost insulating layers have higher curing temperatures, melting points, or glass transition points of the resins contained therein. The thermal curing conditions, such as temperature and time, may be set within a range that does not adversely affect battery characteristics.

[0112] The electrode terminal 80 is a film-like member that covers the first insulating film 70 from the outside and is electrically connected to the electrode layer 10. Specifically, the electrode terminal 80 extends from the outer surface of the first insulating film 70 around to the electrode main surface 2, which is the main surface of the electrode current collector 11, and continuously covers the first insulating film 70 and at least a portion of the electrode main surface 2. The electrode terminal 80 covers both sides in the stacking direction and the ends of the power generating element 1 from the outside of the power generating element 1. The electrode terminal 80 does not contact the side surface of the power generating element 1 or the counter electrode main surface 3. The electrode terminal 80 may contact the side surface of the power generating element 1 as long as it does not contact the counter electrode layer 20. Note that two electrode terminals 80 are provided along the first side surface 6 and the second side surface 7, but only one of the two electrode terminals 80 may be provided. In other words, one of the first side surface 6 and the second side surface 7 may be covered by only the first insulating film 70 of the first insulating film 70 and the electrode terminal 80.

[0113] The electrode terminal 80 has a second side surface covering portion 81 that covers the first side surface covering portion 71 of the first insulating film 70, an electrode contact portion 82 that is joined to the electrode main surface 2, and a second main surface covering portion 83 that covers the first main surface covering portion 72 of the first insulating film 70. The second side surface covering portion 81, the electrode contact portion 82, and the second main surface covering portion 83 are continuous and connected.

[0114] The second side surface covering portion 81 covers the outside of the first insulating film 70, in other words, the surface of the first insulating film 70 opposite to the power generating element 1 side. The second side surface covering portion 81 is in contact with, for example, the outside surface of the first insulating film 70 and is joined to the first insulating film 70. The second side surface covering portion 81 covers the first side surface covering portion 71. Specifically, the second side surface covering portion 81 covers the first side surface covering portion 71 of the first insulating film 70 from the outside and is in contact with the first side surface covering portion 71.

[0115] The electrode contact portion 82 covers at least a portion of the electrode principal surface 2 and is joined to the electrode principal surface 2. The electrode contact portion 82 is electrically connected to, for example, the electrode current collector 11. The electrode contact portion 82 is in contact with an end portion of the electrode principal surface 2. As a result, the electrode contact portion 82 is in contact with the end portion of the electrode principal surface 2 on the electrode terminal 80 side, so that the electrode terminal 80 does not need to extend significantly inside the electrode principal surface 2, and the electrode terminal 80 and the electrode layer 10 can be easily electrically connected. In a plan view, the inner end portion of the second principal surface covering portion 83 and the inner end portion of the portion where the electrode contact portion 82 covers the electrode principal surface 2 are, for example, at the same position.

[0116] The second principal surface covering portion 83 covers the first principal surface covering portion 72 from the outside (i.e., the side opposite the counter electrode principal surface 3 side of the first principal surface covering portion 72) and is in contact with the first principal surface covering portion 72. In other words, the second side surface covering portion 81 and the second principal surface covering portion 83 wrap around from the outer surface of the first side surface covering portion 71 of the first insulating film 70 to the outer surface of the first principal surface covering portion 72, covering the first insulating film 70. In plan view, the inner end of the second principal surface covering portion 83 is located outward of the inner end of the first principal surface covering portion 72. In this way, the second principal surface covering portion 83 covers the first principal surface covering portion 72, thereby forming a structure in which the electrode terminal 80 sandwiches the end of the power generating element 1 in the stacking direction, thereby preventing peeling of the layers of the power generating element 1. Furthermore, both the electrode terminal 80 and the counter electrode terminal 90 can be joined to a substrate or the like on the counter electrode principal surface 3 side of the power generating element 1. The electrode terminal 80 does not necessarily have to have the second main surface covering portion 83.

[0117] The thickness of the electrode terminal 80 is not particularly limited. From the viewpoint of the volumetric energy density of the battery 100, the thickness of the electrode terminal 80, particularly the thickness of the electrode contact portion 82, may be thinner than the thickness of the current collector. The thickness of the electrode terminal 80, particularly the thickness of the electrode contact portion 82, may be, for example, 1 μm or more and 50 μm or less, or 2 μm or more and 40 μm or less. When the thickness of the electrode terminal 80 is within the above range, stress caused by expansion or contraction of the current collector due to temperature changes can be easily alleviated while suppressing a decrease in volumetric energy density, and the characteristics of the battery 100 can be stably obtained.

[0118] Furthermore, if the surface facing in the direction from the electrode main surface 2 toward the counter electrode main surface 3 is the bottom surface, the distance from the counter electrode main surface 3 to the bottom surface of the electrode terminal 80 is, for example, the same as the distance from the counter electrode main surface 3 to the bottom surface of the second main surface covering portion 83.

[0119] The counter electrode terminal 90 is a pad-shaped, or in other words, plate-shaped, member bonded to the counter electrode principal surface 3 and electrically connected to the counter electrode layer 20. This allows the counter electrode terminal 90 and the counter electrode principal surface 3 to be bonded over a wide area, ensuring a strong bond even when the battery 100 is mounted on a substrate. Furthermore, the resistance of the counter electrode terminal 90, which serves as a conductive path when bonded to a substrate, is reduced, thereby reducing localized heat generation. In the example shown in FIG. 1 , one main surface of the counter electrode terminal 90 is in contact with the counter electrode principal surface 3, which is the surface of the counter electrode current collector 21. The counter electrode terminal 90 is disposed opposite the counter electrode layer 20 and is layered on the counter electrode principal surface 3 of the counter electrode layer 20. In plan view, the counter electrode terminal 90 is entirely located inside the outer periphery of the counter electrode principal surface 3 and overlaps with the counter electrode principal surface 3. In other words, the counter electrode terminal 90 entirely overlaps with the counter electrode current collector 21 in plan view. This results in a structure in which the counter electrode terminal 90 does not protrude from the counter electrode main surface 3 in plan view, allowing the battery 100 to be further miniaturized.

[0120] Furthermore, the counter electrode terminal 90 is located, for example, in the center of the counter electrode main surface 3 in plan view. The center of the counter electrode main surface 3 is, for example, a region that is 5% or more inward from the outer periphery of the counter electrode main surface 3 of the distance between the opposing sides of the counter electrode main surface 3. The center of the counter electrode main surface 3 may also be a region that is 10% or more inward from the outer periphery of the counter electrode main surface 3 of the distance between the opposing sides of the counter electrode main surface 3. Furthermore, in the example shown in FIG. 1 , the center of the counter electrode terminal 90 and the center of the counter electrode main surface 3 overlap in plan view.

[0121] The counter electrode terminal 90 has a circular shape in a plan view, but is not particularly limited thereto, and may have a shape other than a circle, such as a rectangle, an ellipse, or a polygon. The thickness of the counter electrode terminal 90 is not particularly limited as long as it does not cause any problems in use. The thickness of the counter electrode terminal 90 is, for example, 1 μm or more and 50 μm or less, and may be 2 μm or more and 40 μm or less. When the thickness of the counter electrode terminal 90 is within the above range, stress caused by expansion or contraction of the current collector due to temperature changes can be easily alleviated while suppressing a decrease in volumetric energy density, and the characteristics of the battery 100 can be stably obtained.

[0122] Furthermore, the size of the counter electrode terminal 90 in plan view is not particularly limited, but from the viewpoint of increasing the bonding area between the battery 100 and the substrate when mounting the battery 100 on the substrate, the size may be, for example, 5% or more, or 10% or more, of the area of ​​the counter electrode main surface 3.

[0123] By providing the counter electrode terminal 90, for example, the electrode layer 10 side and the counter electrode layer 20 side of the power generating element 1 can be easily distinguished from each other by visual inspection or by an automatic machine.

[0124] As will be described in detail later, the electrode terminal 80 and the counter electrode terminal 90 may be covered with a solder layer made of a solder plating film or the like so that they can be easily mounted on a substrate by soldering.

[0125] Hereinafter, the electrode terminal 80 and the counter electrode terminal 90 may be collectively referred to simply as "terminals."

[0126] The terminals are made of a conductive material that has electronic conductivity. From the viewpoint of alleviating stress on the power generating element 1 caused by expansion or contraction of each layer of the power generating element 1 due to temperature changes, the terminals are made of, for example, a conductive resin material containing resin. Furthermore, when a solder plating film is formed on the terminals, for example, a relatively hard nickel plating base film used as a base film is prone to cracking due to the stress difference between the nickel base film and the terminal in contact with it during thermal cycles. However, when the film is formed on a terminal that serves as a soft buffer material such as a conductive material containing resin, cracking is suppressed, thereby improving thermal durability.

[0127] For example, the Young's modulus of the terminal is lower than that of the metals constituting the electrode current collector 11 and the counter electrode current collector 21. As a result, stress on the terminal caused by temperature changes is alleviated by deformation of the terminal itself. Furthermore, in the electrode terminal 80, stress on the electrode terminal 80 is also alleviated by deformation of the first insulating film 70 underlying the electrode terminal 80. Because the terminal can deform together with the insulating film, it can follow deformation of the power generating element 1 caused by thermal shock and charge / discharge cycles, thereby suppressing peeling and damage to the power generating element 1. Furthermore, from the viewpoint of alleviating stress on the power generating element 1 and improving the reliability of the battery 100, the Young's modulus of the terminal may be lower than that of the solid electrolyte layer 30. Furthermore, from the viewpoint of alleviating stress on the power generating element 1 caused by expansion or contraction of the electrode active material layer 12 and the counter electrode active material layer 22 due to temperature changes and improving the reliability of the battery 100, the Young's modulus of the terminal may be lower than that of the electrode active material layer 12 and the counter electrode active material layer 22. The relative relationship between these Young's moduli can be compared, for example, from the displacement characteristics relative to the pressure when the probe is pressed in, or the size of the depression.

[0128] The conductive material constituting the terminals includes, for example, at least one of silver, copper, nickel, zinc, aluminum, palladium, gold, platinum, and alloys of these metals.

[0129] The terminals may also be made of a material in which conductive particles or particles of a semiconductor material are contained in a solid electrolyte, which, as described above, can reduce the stress caused by the expansion or contraction of the current collector due to temperature changes while also reducing the resistance component, thereby achieving a high-capacity battery with low loss.

[0130] Furthermore, the terminals may be made of a material in which a solid electrolyte or the like is contained in a conductive resin paste, from the viewpoint of being able to adjust the coefficient of thermal expansion and softness (Young's modulus).

[0131] The resin contained in the conductive material constituting the terminal may be a thermoplastic resin or a thermosetting resin, and among these, from the viewpoint of easily forming the terminal, the terminal may contain a thermosetting resin.

[0132] Here, when both the electrode terminal 80 and the first insulating film 70 contain resin, the processing temperature of the resin contained in the electrode terminal 80 is, for example, lower than the processing temperature of the resin contained in the first insulating film 70. In the case of a thermosetting resin, the processing temperature is, for example, a curing temperature for accelerating the thermosetting of the resin. In the case of a thermoplastic resin, the processing temperature is, for example, a phase transition temperature (for example, a glass transition point or melting point) for the flow of the resin. In the case of a first insulating film 70 containing a first thermosetting resin and a second thermosetting resin containing the electrode terminal 80 containing a second thermosetting resin, for example, the curing temperature of the first thermosetting resin is equal to or higher than the curing temperature of the second thermosetting resin. This allows the curing temperature during the formation of the electrode terminal 80 to be equal to or lower than the curing temperature of the first thermosetting resin contained in the first insulating film 70. Therefore, the electrode terminal 80 can be formed while suppressing deterioration in the properties of the first insulating film 70 and suppressing peeling and cracking of the first insulating film 70.

[0133] Examples of thermoplastic resins include polyethylene resins, polypropylene resins, acrylic resins, polystyrene resins, vinyl chloride resins, silicone resins, polyamide resins, polyimide resins, fluorinated hydrocarbon resins, polyether resins, butadiene rubber, isoprene rubber, styrene-butadiene rubber (SBR), styrene-butadiene-styrene copolymer (SBS), styrene-ethylene-butadiene-styrene copolymer (SEBS), ethylene-propylene rubber, butyl rubber, chloroprene rubber, and acrylonitrile-butadiene rubber.

[0134] Examples of thermosetting resins include (i) amino-based resins such as urea-based resins, melamine-based resins, and guanamine-based resins; (ii) epoxy-based resins such as bisphenol A-type, bisphenol F-type, phenol novolac-type, and alicyclic-type; (iii) oxetane-based resins; (iv) phenol-based resins such as resol-type and novolac-type; and (v) silicone-modified organic resins such as silicone epoxy and silicone polyester.

[0135] Specifically, the terminals may be made of a conductive paste containing conductive particles such as silver and resin, which is applied using a metal mask or screen printing and then cured. Alternatively, the conductive paste may contain a low-melting-point metal, which is then subjected to a thermal curing process to form an alloy layer at the interface with the current collector, thereby integrating and adhering the paste to the current collector. This results in a terminal with strong adhesion. Examples of low-melting-point metals include powders of tin, tin-zinc alloy, tin-silver alloy, tin-copper alloy, tin-aluminum alloy, tin-lead alloy, indium, indium-silver alloy, indium-zinc alloy, indium-tin alloy, bismuth, bismuth-silver alloy, bismuth-nickel alloy, bismuth-tin alloy, bismuth-zinc alloy, or bismuth-lead alloy. The type of low-melting-point metal is selected taking into consideration the heat resistance of the components of the battery 100. In particular, when a low-melting-point metal is crushed to 10 μm or less, sintering proceeds even during a curing process at approximately half the melting point, resulting in strong adhesion between the terminal and the current collector. Furthermore, The terminals may be configured by attaching plate-shaped conductors made of stainless steel, copper, nickel, or the like with a conductive adhesive or solder.

[0136] The terminals may be made of a material having pores or bubbles containing air, etc. Such a structure allows the softness (e.g., Young's modulus) to be controlled over a wide range, thereby further reducing stress on the power generating element 1 caused by expansion or contraction of each layer of the power generating element 1 due to temperature changes.

[0137] The terminals may also contain non-flammable materials such as metals, ceramics, solid electrolytes, etc. When the terminals contain a non-flammable material, it also has the effect of acting as a layer wall that prevents the battery from spreading when it generates abnormal heat.

[0138] The terminal may also have a laminated structure of multiple conductive layers each made of a conductive material, and the conductive materials of the multiple conductive layers may be the same or different.

[0139] The electrode terminal 80 and the counter electrode terminal 90 may be made of the same material or different materials. When the electrode terminal 80 and the counter electrode terminal 90 are made of different materials, at least one of the electrode terminal 80 and the counter electrode terminal 90 may satisfy the material, physical properties, etc. of the terminals described above.

[0140] With the above configuration, a highly reliable battery 100 can be realized.

[0141] When the configuration of battery 100 according to this embodiment is compared with the configurations of the batteries described in Patent Documents 1 and 2, the following differences are found.

[0142] Patent Document 1 discloses an all-solid-state battery with a structure in which an insulating material is used on the side walls of a power generating element and current is extracted using tab leads. Therefore, when a terminal electrode is extracted using a lead wire such as a tab lead, the terminal electrode is likely to come into contact with other parts of the battery, causing a short circuit due to bending and deformation of the battery during charging and discharging. Furthermore, burrs (dust) that fall off during battery processing can adhere to the current collector, causing a short circuit. Furthermore, the exposed end of the current collector is prone to peeling from the active material layer. Thus, conventional configurations have had reliability issues. These problems become more pronounced as batteries become smaller and more multilayered. According to the configuration of the present embodiment, current can be extracted using an electrode terminal 80 and a counter electrode terminal 90 from a power generating element 1, each layer of which is constrained by a first insulating film 70 that forms the side walls. Furthermore, by joining the electrode terminal 80 and the counter electrode terminal 90 of the battery 100 to a substrate, a battery with excellent bending resistance can be obtained. Furthermore, since no lead wires are used, a small, highly reliable battery 100 can be realized that prevents short circuits.

[0143] Patent Document 2 also discloses a battery pack in which multiple batteries are connected with tab leads. However, the battery pack in Patent Document 2 has a structure in which the batteries are connected with lead wires and each layer of the power generating element is exposed at the side walls. As a result, it is prone to deformation and damage, and delamination is also likely to occur at the exposed side wall edges. As a result, it is prone to short circuits.

[0144] In contrast, it is clear that these problems do not occur with the battery 100 according to the present embodiment. Furthermore, Patent Documents 1 and 2 do not disclose or suggest the battery having terminals and insulating films or the stacked battery formed by stacking batteries, as described in the present embodiment.

[0145] [Variation 1] The following describes Variation 1 of Embodiment 1. In the following description of Variation 1, differences from Embodiment 1 will be mainly described, and explanations of commonalities will be omitted or simplified. The same applies to Variations 2 and onward described below; in the description of each variation, differences from Embodiment 1 and each variation will be mainly described, and explanations of commonalities will be omitted or simplified.

[0146] Figure 2 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 1 of Embodiment 1. Specifically, Figure 2(a) is a cross-sectional view of a battery 101 according to this modification, and Figure 2(b) is a plan view of the battery 101 as seen from below in the z-axis direction. Figure 2(a) shows a cross section taken along line IIa-IIa in Figure 2(b).

[0147] As shown in FIG. 2, the battery 101 according to the first modification of the first embodiment differs from the battery 100 in the embodiment in that it has two rectangular counter terminals 90a, one large and one small, instead of the counter terminal 90.

[0148] The battery 101 includes a plurality of counter electrode terminals 90a. The shape and number of the counter electrode terminals 90a are not particularly limited. The shapes of the plurality of counter electrode terminals 90a may be the same or different from each other.

[0149] In this way, by forming multiple counter electrode terminals 90a on the counter electrode main surface 3, the area of ​​each counter electrode terminal 90a can be made smaller than when a single counter electrode terminal is formed, thereby reducing problems such as voids due to air and residual solvent components and printing plate separation, and enabling the printing of a uniform film. Furthermore, by reducing the area of ​​each counter electrode terminal 90a, the influence of heat is dispersed, improving resistance to thermal shock and heat resistance. Furthermore, for example, in the configuration shown in FIG. 2, by forming counter electrode terminals 90a with different shapes in a plan view on the counter electrode main surface 3, the relative sizes of the two counter electrode terminals 90a can be used to visually indicate the direction of the power generating element 1.

[0150] [Variation 2] Next, a second modification of the first embodiment will be described. Fig. 3 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to the second modification of the first embodiment. Specifically, Fig. 3(a) is a cross-sectional view of a battery 102 according to this modification, and Fig. 3(b) is a plan view of the battery 102 as seen from below in the z-axis direction. Fig. 3(a) shows a cross section taken along line IIIa-IIIa in Fig. 3(b).

[0151] As shown in FIG. 3, a battery 102 according to the second modification of the first embodiment differs from the battery 100 in the first embodiment in that it further includes a second insulating film 75 that covers the counter electrode main surface 3.

[0152] As described above, the battery 102 includes, in addition to the components of the battery 100, the second insulating film 75 that covers a portion of the counter electrode main surface 3. The second insulating film 75 is in contact with the counter electrode main surface 3. The second insulating film 75 is connected to the first main surface covering portion 72 of the first insulating film 70. This allows the first insulating film 70 and the second insulating film 75 to form a continuous covering film, which further enhances reinforcement and improves the flexural strength of the battery 102. This improves the flexural resistance of the battery 102.

[0153] The second insulating film 75 also covers the outer periphery of the counter electrode terminal 90 in a planar view. The second insulating film 75 is disposed so as to surround the counter electrode terminal 90 in a planar view. This makes it possible to suppress peeling of the counter electrode terminal 90 starting from the outer periphery of the counter electrode terminal 90. Furthermore, by disposing the second insulating film 75 around the counter electrode terminal 90, the second insulating film 75 also acts as a structural reinforcing layer, thereby improving the flexural strength of the battery 102. Note that, in the example shown in FIG. 3, the second insulating film 75 covers the entire outer periphery of the counter electrode terminal 90 in a planar view, but it may also cover only a portion of the outer periphery. The first insulating film 70 and the second insulating film 75 may be spaced apart.

[0154] The second insulating film 75 covers the entire counter electrode principal surface 3 except for the region in contact with the counter electrode principal surface 3, the first principal surface covering portion 72, and the counter electrode terminal 90. An opening 77 is formed in the second insulating film 75. The opening 77 exposes the counter electrode terminal 90 to the outside. In other words, the second insulating film 75 does not cover at least a portion of the counter electrode terminal 90.

[0155] The height of the counter electrode terminal 90 from the counter electrode main surface 3 is lower than the height of the second insulating film 75 from the counter electrode main surface 3. The surface formed by the second insulating film 75 and the counter electrode terminal 90 is recessed at the location of the counter electrode terminal 90. In addition, in the battery 102, an outer peripheral edge portion 91 of the counter electrode terminal 90 in a plan view is sandwiched between the counter electrode main surface 3 and the second insulating film 75. That is, the outer peripheral edge portion 91 of the counter electrode terminal 90 is covered with the second insulating film 75 and is not exposed. By covering the lower surface of the outer peripheral edge portion 91 of the counter electrode terminal 90 with the second insulating film 75, peeling of the outer peripheral edge portion 91 of the counter electrode terminal 90 from the counter electrode main surface 3 is suppressed. The height of the counter electrode terminal 90 from the counter electrode main surface 3 may be the same as the height of the second insulating film 75 from the counter electrode main surface 3, or may be higher than the height of the second insulating film 75 from the counter electrode main surface 3. That is, the surface formed by the second insulating film 75 and the counter electrode terminal 90 may be a flat surface, or the portion of the counter electrode terminal 90 may be convex.

[0156] The material of the second insulating film 75 can be, for example, the material described above as the material of the first insulating film 70. The material of the second insulating film 75 may be the same as the material of the first insulating film 70, or may be different from the material of the first insulating film 70. When the first insulating film 70 and the second insulating film 75 are made of the same material, the first insulating film 70 and the second insulating film 75 may be integrally formed as a single insulating film.

[0157] [Variation 3] Next, a third modification of the first embodiment will be described. Fig. 4 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to the third modification of the first embodiment. Specifically, Fig. 4(a) is a cross-sectional view of a battery 103 according to this modification, and Fig. 4(b) is a plan view of the battery 103 as seen from below in the z-axis direction. Fig. 4(a) shows a cross section taken along line IVa-IVa in Fig. 4(b).

[0158] As shown in FIG. 4, the battery 103 according to the third modification of the first embodiment differs from the battery 102 according to the second modification of the first embodiment in that it includes a first insulating film 70c instead of the first insulating film 70.

[0159] The first insulating film 70c covers an end 84 of the second main surface covering portion 83 of the electrode terminal 80. The first insulating film 70c has a first side surface covering portion 71 and a first main surface covering portion 72c. The first main surface covering portion 72c covers the counter electrode main surface 3 and also extends around to the outer surface of the second main surface covering portion 83, contacting and covering the end 84 of the electrode terminal 80 (specifically, the second main surface covering portion 83). In this way, the first insulating film 70c covers the end 84 of the electrode terminal 80, thereby suppressing peeling of the electrode terminal 80 due to stress caused by bending and thermal shock, etc., during solder mounting.

[0160] [Variation 4] Next, a fourth modification of the first embodiment will be described. Fig. 5 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to the fourth modification of the first embodiment. Specifically, Fig. 5(a) is a cross-sectional view of a battery 104 according to this modification, and Fig. 5(b) is a plan view of the battery 104 as seen from below in the z-axis direction. Fig. 5(a) shows a cross section taken along the line Va-Va in Fig. 5(b).

[0161] As shown in FIG. 5, a battery 104 according to the fourth modification of the first embodiment differs from the battery 100 of the first embodiment in that it includes an electrode terminal 80d instead of the electrode terminal 80.

[0162] The electrode terminal 80d has a second side surface covering portion 81, an electrode contact portion 82d, and a second main surface covering portion 83. In the battery 104, in a plan view, the length of the electrode contact portion 82d from the first side surface 6 is longer than the length of the second main surface covering portion 83 from the first side surface 6. This increases the bonding area between the electrode terminal 80d and the electrode main surface 2, thereby suppressing peeling of the electrode terminal 80d at the electrode contact portion 82d and reducing the resistance for extracting current from the electrode layer 10.

[0163] [Variation 5] Next, a fifth variation of the first embodiment will be described. Fig. 6 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to the fifth variation of the first embodiment. Specifically, Fig. 6(a) is a cross-sectional view of a battery 105 according to this variation, and Fig. 6(b) is a plan view of the battery 105 as seen from below in the z-axis direction. Fig. 6(a) shows a cross section taken along line VIa-VIa in Fig. 6(b).

[0164] 6, the battery 105 according to the fifth modification of the first embodiment differs from the battery 100 in the first embodiment in that the first insulating film 70 and the electrode terminal 80 are provided only along the first side surface 6, rather than along both the first side surface 6 and the second side surface 7 that face each other. The battery 105 also differs from the battery 100 in the first embodiment in that the battery 105 includes a counter terminal 90e instead of the counter terminal 90.

[0165] The battery 105 includes one first insulating film 70 and one electrode terminal 80. In the battery 105, the one first insulating film 70 and the one electrode terminal 80 are provided along the first side surface 6. The second side surface 7 is not covered by the first insulating film 70 or the electrode terminal 80. This makes it possible to realize the battery 105 that is suitable for a small installation form in which current is extracted only from one side surface of the power generating element 1.

[0166] In a plan view, the distance from the second side surface 7 to the counter electrode terminal 90e is shorter than the distance from the first side surface 6 to the counter electrode terminal 90e. In other words, the counter electrode terminal 90e is disposed closer to the second side surface 7, on which the first insulating film 70 and the electrode terminal 80 are not provided, than to the first side surface 6, on which the first insulating film 70 and the electrode terminal 80 are provided. With this arrangement, when mounted on a substrate, the electrode terminal 80 closer to the first side surface 6 and the counter electrode terminal 90e closer to the second side surface 7 are bonded to the substrate, thereby strengthening the bonded structure.

[0167] In the battery 105, the first insulating film 70 and the electrode terminal 80 are provided along the first side surface 6 on the short side of the power generating element 1 in a planar view, but they may also be provided along the side surface on the long side of the power generating element 1 in a planar view.

[0168] [Variation 6] Next, a sixth variation of the first embodiment will be described. Fig. 7 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to the sixth variation of the first embodiment. Specifically, Fig. 7(a) is a cross-sectional view of a battery 106 according to this variation, and Fig. 7(b) is a plan view of the battery 106 as seen from below in the z-axis direction. Fig. 7(a) shows a cross section taken along line VIIa-VIIa in Fig. 7(b).

[0169] 7, the battery 106 according to the sixth modification of the first embodiment differs from the battery 105 according to the fifth modification of the first embodiment in that it further includes a second insulating film 75f. The battery 106 also differs from the battery 102 according to the second modification of the first embodiment in that it includes a second insulating film 75f and a counter electrode terminal 90e instead of the second insulating film 75 and the counter electrode terminal 90, and that the first insulating film 70 and the electrode terminal 80 are provided only along the first side surface 6, rather than along both the first side surface 6 and the second side surface 7 that face each other.

[0170] The second insulating film 75f covers the outer periphery of the counter electrode terminal 90e in plan view. The second insulating film 75f is disposed so as to surround the counter electrode terminal 90e in plan view. The second insulating film 75f also covers the side surfaces of the long sides of the power generating element 1 in plan view.

[0171] In this way, the battery 106 is configured by combining the battery 102 and the battery 106. Therefore, it is possible to realize the battery 106 which is suitable for a small installation form in which the current is extracted only from one side surface of the power generating element 1, while suppressing peeling of the counter electrode terminal 90e.

[0172] [Variation 7] Next, a seventh modification of the first embodiment will be described. Fig. 8 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to the seventh modification of the first embodiment. Specifically, Fig. 8(a) is a cross-sectional view of a battery 107 according to this modification, and Fig. 8(b) is a plan view of the battery 107 as seen from below in the z-axis direction. Fig. 8(a) shows a cross section taken along line VIIIa-VIIIa in Fig. 8(b).

[0173] 8, battery 107 according to Variation 7 of Embodiment 1 differs from battery 100 in the embodiment in that it includes a power generating element 1g having a structure in which a plurality of battery cells 50 are connected in series and stacked, instead of power generating element 1. Battery 107 also differs from battery 100 in the embodiment in that it includes a first insulating film 70g and an electrode terminal 80g, instead of first insulating film 70 and electrode terminal 80.

[0174] The power generating element 1g has a plurality of battery cells 50, specifically two battery cells 50. The number of battery cells 50 included in the power generating element 1g is not limited to two, and may be three or more. The power generating element 1g also has a conductive connection layer 40 between adjacent battery cells 50 among the plurality of battery cells 50.

[0175] The power generating element 1g has an electrode principal surface 2g which is a principal surface formed by the surface of the electrode layer 10 of the uppermost battery cell 50, a counter electrode principal surface 3g which is a principal surface formed by the surface of the counter electrode layer 20 of the lowermost battery cell 50, and side surfaces. The side surfaces include a first side surface 6g and a second side surface 7g which are both side surfaces on the shorter sides of the power generating element 1g in a plan view.

[0176] The plurality of battery cells 50 are electrically connected in series and stacked. The plurality of battery cells 50 are stacked such that the electrode layer 10 of one of the plurality of adjacent battery cells 50 and the counter electrode layer 20 of the other are adjacent to each other via the connection layer 40, without the solid electrolyte layer 30 sandwiched therebetween. In other words, the plurality of battery cells 50 are stacked such that the electrode layer 10 and the counter electrode layer 20 of each battery cell 50 are in the same up-down position. In this modification, the electrode layer 10 (specifically, the electrode current collector 11) of one of the adjacent battery cells 50 and the counter electrode layer 20 (specifically, the counter electrode current collector 21) are electrically connected by the connection layer 40, thereby stacking the plurality of battery cells 50 in an electrically connected series manner. In other words, the power generating element 1g has a bipolar electrode in which the electrode layer 10 and the counter electrode layer 20 are connected without the solid electrolyte layer 30 interposed therebetween.

[0177] The power generating element 1g may not include the connection layer 40, and the plurality of battery cells 50 may be stacked such that one electrode layer 10 and the other counter electrode layer 20 of adjacent battery cells 50 are adjacent to each other without the connection layer 40 interposed therebetween. For example, the plurality of battery cells 50 may be stacked while electrically connected in series, with one electrode layer 10 and the other counter electrode layer 20 of adjacent battery cells 50 being in direct contact with each other and electrically connected. Alternatively, one electrode layer 10 and the other counter electrode layer 20 of adjacent battery cells 50 may share a single current collector.

[0178] The connection layer 40 is made of, for example, a conductive material having electronic conductivity. The conductive material that constitutes the connection layer 40 is not particularly limited, but the conductive materials exemplified above as the conductive material that constitutes the terminals can be used as the conductive material.

[0179] The first insulating film 70g has a first side surface covering portion 71g that covers the side surface of the power generating element 1g, and a first main surface covering portion 72g that covers the counter electrode main surface 3g.

[0180] The first side surface covering portion 71g, for example, contacts the first side surface 6g, covers the first side surface 6g, and is joined to the first side surface 6g. The first side surface covering portion 71g continuously covers the first side surface 6g from the end on the electrode principal surface 2g side to the end on the counter electrode principal surface 3g side. In this way, the first side surface covering portion 71g collectively covers the side surfaces of the multiple battery cells 50.

[0181] The first principal surface covering portion 72g is in contact with, for example, the counter electrode principal surface 3g and is joined to the counter electrode principal surface 3g. The first principal surface covering portion 72g covers the end portion of the counter electrode principal surface 3g.

[0182] The first side surface covering portion 71g and the first main surface covering portion 72g are continuous and connected. That is, the first insulating film 70g extends from the first side surface 6g onto the counter electrode main surface 3g that is formed by the main surface of the counter electrode current collector 21, and continuously covers the ridge line between the first side surface 6g and the counter electrode main surface 3g.

[0183] The electrode terminal 80g has a second side surface covering portion 81g that covers the first side surface covering portion 71g of the first insulating film 70g, an electrode contact portion 82g that is joined to the electrode main surface 2g, and a second main surface covering portion 83g that covers the first main surface covering portion 72g of the first insulating film 70g. The second side surface covering portion 81g, the electrode contact portion 82g, and the second main surface covering portion 83g are continuous and connected.

[0184] The second side surface covering portion 81g covers the outside of the first insulating film 70g, in other words, the surface of the first insulating film 70g opposite to the power-generating element 1g side. The second side surface covering portion 81g is in contact with, for example, the outside surface of the first insulating film 70g and is joined to the first insulating film 70g. The second side surface covering portion 81g covers the first side surface covering portion 71g.

[0185] The electrode contact portion 82g covers at least a portion of the electrode principal surface 2g and is joined to the electrode principal surface 2g.

[0186] The second principal surface covering portion 83g covers the outside of the first insulating film 70g, in other words, the surface of the first insulating film 70g opposite to the power-generating element 1g side. The second principal surface covering portion 83g is in contact with, for example, the outside surface of the first insulating film 70g and is joined to the first insulating film 70g. The second principal surface covering portion 83g covers the first principal surface covering portion 72g from the outside and is in contact with the first principal surface covering portion 72g.

[0187] In the battery 107, the counter electrode terminal 90 is provided only on the counter electrode current collector 21 of the bottommost battery cell 50. The counter electrode terminal 90 may also be provided on the counter electrode current collector 21 of a battery cell 50 other than the bottommost battery cell 50, and for example, a plurality of battery cells 50 may be joined via the counter electrode terminal 90. In this case, the counter electrode terminal 90 formed on the counter electrode current collector 21 can also be used as an alignment reference for positioning when stacking the battery cells 50, eliminating the need to provide an alignment mark on the battery cell 50.

[0188] This structure, which integrates the terminal, the first insulating film 70g, and the power generating element 1g, which is formed by connecting and stacking multiple battery cells 50, enables high voltage to be generated and also suppresses short circuits and peeling of the layers of the power generating element 1g. This results in a high-energy, highly reliable battery 107. Furthermore, similar to the battery 100, by bonding the electrode terminal 80g and counter electrode terminal 90 of the battery 107 to a substrate, the battery 107 has excellent resistance to bending.

[0189] [Variation 8] Next, an eighth modification of the first embodiment will be described. Fig. 9A is a cross-sectional view and a plan view showing a schematic configuration of a battery according to the eighth modification of the first embodiment. Specifically, (a) of Fig. 9A is a cross-sectional view of a battery 108 according to this modification, and (b) of Fig. 9A is a plan view of the battery 108 as seen from below in the z-axis direction. (a) of Fig. 9A shows a cross section taken along line IXa-IXa in (b) of Fig. 9A.

[0190] 9A, the battery 108 according to the eighth modification of the first embodiment differs from the battery 100 according to the first embodiment in that it further includes an electrode solder layer 85 and a counter electrode solder layer 95. Hereinafter, the electrode solder layer 85 and the counter electrode solder layer 95 may be collectively referred to simply as the "solder layer."

[0191] The electrode solder layer 85 covers the electrode terminal 80 and is in contact with the electrode terminal 80. The electrode solder layer 85 covers, for example, the outer surface of the electrode terminal 80, specifically, the surface of the electrode terminal 80 that is not in contact with either the electrode main surface 2 or the first insulating film 70. The electrode solder layer 85 may cover the entire outer surface of the electrode terminal 80, or may cover only a part of that surface. The electrode solder layer 85 may, for example, cover only the outer surface of the second main surface covering portion 83.

[0192] The counter electrode solder layer 95 covers the counter electrode terminal 90 and is in contact with the counter electrode terminal 90. The counter electrode solder layer 95 covers, for example, the outer surface of the counter electrode terminal 90, specifically, the surface of the counter electrode terminal 90 that is not in contact with the counter electrode main surface 3. The counter electrode solder layer 95 may cover the entire outer surface of the counter electrode terminal 90, or may cover only a part of that surface. The counter electrode solder layer 95 may, for example, cover only the surface of the outer surface of the counter electrode terminal 90 that faces the counter electrode main surface 3.

[0193] The electrode solder layer 85 and the counter electrode solder layer 95 may cover the surfaces other than the electrode terminal 80 and the counter electrode terminal 90, respectively, as long as they do not electrically connect the electrode layer 10 and the counter electrode layer 20.

[0194] The solder layer contains solder as a main component, which allows the battery 108 to be easily solder-mounted to a substrate, etc. Furthermore, when a conductive paste containing silver is used for the terminals, the solder layer acts as a blocking layer, improving migration resistance.

[0195] The solder layer is formed, for example, by a solder plating film obtained by plating each terminal. The thickness of the solder plating film is, for example, 1 μm to 10 μm. This suppresses the occurrence of cracks due to film formation stress and thermal shock. Although not shown, from the viewpoint of improving mountability and reliability on a substrate, the solder plating film includes, for example, a nickel plating base film in contact with the surface of the terminal and a tin plating film formed on the nickel plating base film. The nickel plating base film contains nickel as a main component, and the tin plating film contains tin as a main component. From the viewpoint of mountability and reliability on a substrate, for example, the thickness of the nickel plating base film is, for example, 1 μm to 5 μm, and the thickness of the tin plating film is, for example, 0.5 μm to 5 μm. The thickness of the solder plating film can be measured by a common plating thickness evaluation method, for example, cross-sectional observation using an optical microscope or an electron microscope, or fluorescent X-ray measurement. The solder layer does not have to be formed by a solder plating film, but may be formed, for example, by solder paste or the like.

[0196] Furthermore, if the surface extending from the electrode principal surface 2 toward the counter electrode principal surface 3 is considered to be the bottom surface, the distance from the counter electrode principal surface 3 to the bottom surface of the electrode solder layer 85 is the same as, for example, the distance from the counter electrode principal surface 3 to the bottom surface of the counter electrode solder layer 95.

[0197] 9A, the configuration of the battery 100 according to the first embodiment further includes an electrode solder layer 85 and a counter electrode solder layer 95, but this is not limiting. The configuration of the batteries according to the first to seventh modifications of the first embodiment may further include an electrode solder layer 85 and a counter electrode solder layer 95.

[0198] Furthermore, for example, a second insulating film 75h may be further provided in the configuration of the battery 108. Fig. 9B is a cross-sectional view showing a schematic configuration of another battery 108A according to Variation 8 of the first embodiment.

[0199] As shown in FIG. 9B, the battery 108A includes a second insulating film 75h in addition to the configuration of the battery 108 described above.

[0200] The second insulating film 75h is in contact with the counter electrode main surface 3. The second insulating film 75h is connected to the first main surface covering portion 72 of the first insulating film 70. The second insulating film 75h also covers the outer periphery of the counter electrode terminal 90 in a plan view. As a result, when the battery 108A is solder-mounted on a substrate using the counter electrode solder layer 95, cracks that tend to occur in the counter electrode solder layer 95 due to sudden heating (for example, cracks that typically form an arc from the edge of the counter electrode solder layer 95) are suppressed by limiting solder wetting due to the second insulating film 75h covering the outer periphery of the counter electrode terminal 90. This makes it possible to achieve solder bonding to a substrate that is excellent in adhesion, electrical resistance, and heat dissipation.

[0201] Furthermore, the second insulating film 75h covers the outer periphery and outer edge of the counter electrode terminal 90 in a planar view via the counter electrode solder layer 95. That is, a portion of the counter electrode solder layer 95 is located between the counter electrode terminal 90 and the second insulating film 75h and is in contact with both the counter electrode terminal 90 and the second insulating film 75h. For example, when forming the solder layer, such a structure can be formed by infiltrating a plating liquid into the gap between the counter electrode terminal 90 and the second insulating film 75h by a decompression process or the like. This enhances the anchor effect of the counter electrode solder layer 95, thereby enhancing the effect of the second insulating film 75h in suppressing peeling of the counter electrode terminal 90, thereby forming a counter electrode terminal 90 that is more firmly bonded to the counter electrode main surface 3.

[0202] Furthermore, the second insulating film 75h covers the end of the electrode terminal 80 (specifically, the second main surface covering portion 83) via the electrode solder layer 85. This provides the electrode terminal 80 with the same effect as that achieved by covering the outer periphery and outer peripheral edge portion of the counter electrode terminal 90 with the counter electrode solder layer 95.

[0203] [Variation 9] Next, a description will be given of a ninth modification of the first embodiment. Fig. 10 is a cross-sectional view showing a schematic configuration of a battery according to the ninth modification of the first embodiment.

[0204] 10, battery 109 according to Variation 9 of Embodiment 1 has a configuration in which battery 100 according to the embodiment is mounted on a substrate 60. That is, battery 109 further includes substrate 60 in addition to the configuration of battery 100. Battery 109 is formed by mounting battery 100 on substrate 60 using solder or the like.

[0205] The substrate 60 is a mounting substrate for mounting the battery 100 including the power generating element 1. The substrate 60 is, for example, a ceramic substrate or a resin substrate. The substrate 60 is disposed on the counter electrode layer 20 side of the power generating element 1, facing the counter electrode main surface 3 of the power generating element 1. The counter electrode terminal 90 is located between the counter electrode layer 20 and the substrate 60. The bending strength of the substrate 60 is higher than the bending strength of the battery 100, for example.

[0206] The substrate 60 has an electrode connection part 61 , a counter electrode connection part 62 , and an insulator layer 63 .

[0207] The electrode connection portion 61 is disposed at a position overlapping the electrode terminal 80 in a plan view, and penetrates the insulator layer 63 in the thickness direction. The electrode connection portion 61 is joined to the electrode terminal 80 directly or by soldering or the like (not shown), and is electrically connected to the electrode layer 10. Note that if the electrode terminal 80 does not have the second principal surface covering portion 83, the electrode connection portion 61 may include a metal terminal or the like that protrudes toward the power generating element 1 side of the substrate 60 and is for connection to the electrode terminal 80.

[0208] The counter electrode connecting part 62 is disposed at a position overlapping with the counter electrode terminal 90 in a plan view, and penetrates the insulator layer 63 in the thickness direction. The counter electrode connecting part 62 is joined to the counter electrode terminal 90 directly or by soldering or the like (not shown), and is electrically connected to the counter electrode layer 20.

[0209] In this way, by joining the electrode connection part 61 to the electrode terminal 80 and the counter electrode connection part 62 to the counter electrode terminal 90, it is possible to extract a current from the side of the substrate 60 opposite to the power generating element 1.

[0210] Examples of materials for the electrode connecting part 61 and the counter electrode connecting part 62 include metals with high electrical conductivity, such as copper, silver, gold, and aluminum.

[0211] The insulator layer 63 is a plate-shaped member made of an insulator and serves as the base of the substrate 60. Examples of materials for the insulator layer 63 include ceramics such as alumina and resin materials such as epoxy resin or phenolic resin. When the insulator layer 63 is made of a material with high thermal conductivity such as alumina, the substrate 60 also functions as a heat sink.

[0212] The battery 109 can be manufactured by, for example, mounting the battery 100 on the substrate 60 using solder or the like.

[0213] In this way, in the battery 109, the electrode terminal 80 and the counter electrode terminal 90 are joined to the substrate 60, and thus the power generating element 1 is fixed by the substrate 60, improving the resistance to bending. In particular, by joining the power generating element 1 via the plate-shaped counter electrode terminal 90, a wide joining area between the substrate 60 and the counter electrode terminal 90 can be ensured, and therefore, even if stress that warps the power generating element 1 occurs due to a thermal cycle or the like, peeling of the power generating element 1 from the substrate 60 can be suppressed.

[0214] The electrode connecting part 61 and the counter electrode connecting part 62 do not have to penetrate the insulator layer 63, and may be, for example, a conductive pattern formed on the insulator layer 63. In this case, current can be extracted from the power generating element 1 side of the substrate 60.

[0215] Furthermore, in battery 109, instead of battery 100 according to embodiment 1, a substrate 60 may be further provided in the configuration of the batteries according to variations 1 to 8 of embodiment 1. For example, when a solder layer is provided as in battery 108, a battery including substrate 60 can be realized by directly reflow mounting battery 108.

[0216] [Battery manufacturing method] Next, an example of a method for manufacturing a battery according to the present embodiment will be described. The following description will focus on a method for manufacturing the battery 108 described in Modification 8 of Embodiment 1 above. In addition, the following description of the manufacturing method will be given for a case in which the electrode layer 10 is a positive electrode layer having an electrode active material layer 12 and a positive electrode current collector as a positive electrode active material layer and a positive electrode current collector, and the counter electrode layer 20 is a negative electrode layer having a counter electrode active material layer 22 and a negative electrode current collector as a negative electrode active material layer and a negative electrode current collector.

[0217] First, pastes to be used for printing the positive electrode active material layer and the negative electrode active material layer are prepared. As the solid electrolyte raw material used for the mixture of the positive electrode active material layer and the negative electrode active material layer, for example, a glass powder of Li2S-P2S5-based sulfide having an average particle size of about 10 μm and mainly composed of triclinic crystals is prepared. For example, the glass powder may have a particle size of 2 to 3 × 10 -3 A glass powder having a high ionic conductivity of about 1000 s / cm can be used as the positive electrode active material. For example, a Li·Ni·Co·Al composite oxide (LiNi 0.8 Co 0.15 Al 0.05 A powder of O2) is used. A paste for a positive electrode active material layer is prepared by dispersing a mixture containing the above-mentioned positive electrode active material and the above-mentioned glass powder in an organic solvent or the like. In addition, as the negative electrode active material, for example, a powder of natural graphite having an average particle size of about 10 μm is used. Similarly, a paste for a negative electrode active material layer is prepared by dispersing a mixture containing the above-mentioned negative electrode active material and the above-mentioned glass powder in an organic solvent or the like.

[0218] Next, copper foil with a thickness of, for example, approximately 30 μm is prepared as the material to be used as the positive electrode current collector and the negative electrode current collector. A paste for a positive electrode active material layer and a paste for a negative electrode active material layer are printed on one surface of each copper foil by screen printing, each in a predetermined shape and with a thickness of 50 μm to 100 μm. The paste for a positive electrode active material layer and the paste for a negative electrode active material layer are dried, for example, at 80°C to 130°C, to a thickness of 30 μm to 60 μm. This results in current collectors (copper foils) on which the positive electrode active material layer and the negative electrode active material layer are formed, i.e., the positive electrode layer and the negative electrode layer (i.e., the electrode layer 10 and the counter electrode layer 20), respectively.

[0219] Next, a paste for a solid electrolyte layer is prepared by dispersing the mixture containing the glass powder in an organic solvent or the like. The paste for a solid electrolyte layer is printed on the surfaces of the active material layers of the positive electrode layer and the negative electrode layer using a metal mask, for example, to a thickness of about 100 μm. Thereafter, the positive electrode layer and the negative electrode layer on which the paste for a solid electrolyte layer is printed are dried at a temperature of 80° C. or higher and 130° C. or lower.

[0220] Next, the solid electrolyte printed on the positive electrode active material layer of the positive electrode layer and the solid electrolyte printed on the negative electrode active material layer of the negative electrode layer are laminated so as to be in contact with and face each other.

[0221] Next, the laminated body is pressed with a pressing mold. Specifically, a 70 μm thick, 5×10 elastic modulus, or the like, is placed between the laminate and a pressing mold plate, i.e., on the top surface of the current collector. 6 An elastic sheet having a pressure of about 300 MPa is inserted. With this configuration, pressure is applied to the laminate via the elastic sheet. Thereafter, for example, the pressurizing mold is pressed at a pressure of 300 MPa for 90 seconds while being heated to 50°C. This results in a battery cell 50. In the battery 108, one battery cell 50 is used as the power generating element 1.

[0222] When manufacturing a battery having a power generating element 1g including multiple battery cells 50, such as battery 107, the same number of battery cells 50 fabricated in this manner as the number included in the power generating element 1g are prepared. Then, a thermosetting conductor paste containing silver particles with an average particle diameter of 0.5 μm is applied to one of the current collectors of the positive and negative electrode layers of the battery cells 50 by screen printing to a thickness of approximately 5 μm as the connection layer 40. The battery cells 50 and other battery cells 50 are then stacked so as to be connected in series via the applied conductor paste. Specifically, the battery cells 50 and other battery cells 50 are stacked so that the current collector serving as the counter electrode of the current collector to which the conductor paste is applied is positioned on the applied conductor paste, and the battery cells 50 and other battery cells 50 are pressure-bonded together. To increase the number of series connections, this process is repeated for the number of battery cells to be multi-layered. After this, the battery cells 50 and other battery cells 50 are pressurized with a pressure of, for example, approximately 1 kg / cm. 2 While the electrode is held stationary with a pressure of 0.01 mm, it is subjected to a heat curing treatment at 100°C to 130°C for 40 minutes to 100 minutes, and then cooled to room temperature. This yields 1 g of the power generating element.

[0223] Returning to the explanation of the manufacturing method of the battery 108, a thermosetting epoxy resin is applied by screen printing to a thickness of approximately 20 μm to 40 μm as the material for the first side surface covering portion 71 on the first side surface 6 and the second side surface 7, which are both side surfaces on the short sides of the power generating element 1 fabricated as described above in a plan view. At this time, the thermosetting epoxy resin is also simultaneously applied to a portion of the long side surface of the power generating element 1. The applied thermosetting epoxy resin is then cured at a temperature of 120°C to 150°C for 1 hour to 3 hours. Next, a thermosetting epoxy resin is applied by screen printing to a thickness of 10 μm to 40 μm as the material for the first main surface covering portion 72 on a portion of the counter electrode main surface 3. The applied thermosetting epoxy resin is then cured at a temperature of 120°C to 150°C for 1 hour to 3 hours. These coating and curing processes are repeated a number of times equal to the number of insulating layers, thereby forming a laminate of the first insulating film 70 having a thickness of, for example, 20 μm to 120 μm. When manufacturing a battery including the second insulating film 75, such as the battery 102, the second insulating film 75 is formed on the counter electrode main surface 3 by, for example, the same method as for the first insulating film 70.

[0224] Next, a thermosetting conductive paste containing, for example, silver particles with an average particle size of 0.5 μm is screen-printed on a portion of the electrode principal surface 2 and the counter electrode principal surface 3 to form a pattern with a thickness of approximately 10 μm as the terminal material. Next, the thermosetting conductive paste containing silver particles is applied by printing onto the surface of the first insulating film 70. The power generating element 1 with the applied conductive paste is then cured at a temperature equal to or lower than the curing temperature used to form the insulating film, for example, at a temperature of 100°C to 130°C for 0.5 hours to 3 hours, thereby forming the terminal. If necessary, the terminal may be formed by laminating the conductive paste in the same manner as the insulating film so that the terminal has the desired thickness.

[0225] Next, a solder layer is formed by plating. The plating process is performed after covering areas other than the desired solder plating film with a material that is resistant to plating solution penetration, such as polyimide tape, and then performing a resist treatment. For example, a nickel plating base film with a thickness of 0.5 μm to 10 μm is formed on the terminal as a base for the solder plating film, and then a tin plating film with a thickness of 0.5 μm to 10 μm is formed on the nickel plating base film. This solder plating process enables reflow mounting when mounting the battery 108 on a substrate 60, etc. In addition, from the perspective of the heat resistance of the solder plating film, for example, a relatively hard nickel plating base film is formed with a thickness equal to or less than the thickness of the terminal. In this case, the thickness of the nickel plating base film is, for example, 5 μm or less. This makes it less likely that the terminal will crack or peel due to stress generated by the nickel plating base film, even when subjected to sudden temperature changes during solder mounting. This improves the adhesion of the solder plating film. Furthermore, when the terminal contains silver, defects caused by cracks in the nickel-plated underlayer, such as open pores or interconnected voids, can cause the silver to dissolve in the solder components, potentially resulting in the terminal's loss. This phenomenon is also known as "solder erosion." For this reason, covering the terminal with a nickel underlayer with a thickness of 5 μm or less can prevent the terminal from being lost due to cracks in the nickel-plated underlayer. While high deposition rates of nickel-plated underlayers can cause high stress and cracks, this problem can be reduced by forming the film on a soft material such as resin. Therefore, using a conductive resin for the terminal, for example, can allow the nickel underlayer to be deposited at a high rate, improving productivity.

[0226] In this way, battery 108 is obtained. In manufacturing battery 107, the same conductive paste may be used for connection layer 40 and the terminal, or different conductive pastes with different curing temperatures or conductive particles may be used. For example, when a thin coating film is to be formed, finer conductive particles such as silver particles or scale-like particles may be used as the conductive particles. Furthermore, a material containing a low-melting point metal may be used for connection layer 40 or the terminal, with the aim of forming an alloy between connection layer 40 or the terminal and the current collector due to the heat generated during curing.

[0227] The manufacturing method of the battery and the order of the steps described above are not limited to the above example. For example, a part of the insulating film may be formed after the plating process. Specifically, when manufacturing a battery including the second insulating film 75, such as the battery 102, the second insulating film 75 may be formed after the plating process.

[0228] In the above-described manufacturing method, the positive electrode active material layer paste, the negative electrode active material layer paste, the solid electrolyte layer paste, and the conductor paste are applied by printing, but the present invention is not limited to this. Examples of printing methods that may be used include doctor blade printing, calendar printing, spin coating, dip coating, inkjet printing, offset printing, die coating, and spray printing.

[0229] The first side surface covering portion 71 and the first main surface covering portion 72 may be formed by applying a thermosetting epoxy resin or the like all at once. Terminals covered with a solder plating film may be joined to the power generating element 1. When manufacturing a battery including the second insulating film 75 or the like, such as the battery 102, the first insulating film 70 and the second insulating film 75 may be formed by applying a thermosetting epoxy resin or the like all at once.

[0230] Alternatively, the first insulating film 70 may be formed by immersing the side surface of the power generating element 1 in a liquid thermosetting resin, covering the side surface of the power generating element 1 with the liquid thermosetting resin, and then thermally curing the resin.

[0231] In the above-described manufacturing method, a thermosetting conductive paste containing silver metal particles is used as an example of the conductive paste, but this is not limiting. The conductive paste may be a thermosetting conductive paste containing highly conductive metal particles with a high melting point (e.g., 400°C or higher), low melting point metal particles (preferably below the hardening temperature of the conductive paste, e.g., 300°C or lower), and a resin. Examples of materials for the high-melting-point highly conductive metal particles include silver, copper, nickel, zinc, aluminum, palladium, gold, platinum, and alloys of these metals. Examples of materials for the low-melting-point metal particles with a melting point of 300°C or lower include tin, tin-zinc alloy, tin-silver alloy, tin-copper alloy, tin-aluminum alloy, tin-lead alloy, indium, indium-silver alloy, indium-zinc alloy, indium-tin alloy, bismuth, bismuth-silver alloy, bismuth-nickel alloy, bismuth-tin alloy, bismuth-zinc alloy, and bismuth-lead alloy. By using a conductor paste containing such low-melting-point metal particles, solid-phase and liquid-phase reactions proceed at the contact points between the metal particles in the conductor paste and the metal constituting the current collector, even at curing temperatures lower than the melting point of the high-melting-point, highly conductive metal particles. As a result, a diffusion region formed by solid-phase and liquid-phase reactions is formed around the contact points at the interface between the conductor paste and the surface of the current collector. Examples of the alloy formed include a highly conductive silver-copper alloy when silver or a silver alloy is used for the conductive metal particles and copper is used for the current collector. Furthermore, a silver-nickel alloy or a silver-palladium alloy can also be formed by combining the conductive metal particles with the current collector. This configuration provides a stronger bond between the conductor paste and the current collector, thereby preventing the bonded portion between the conductor paste and the current collector from peeling due to, for example, thermal cycling or impact.

[0232] The shapes of the high-melting-point highly conductive metal particles and the low-melting-point metal particles may be any shape, such as spherical, scaly, or needle-like. The particle sizes of the high-melting-point highly conductive metal particles and the low-melting-point metal particles are not particularly limited. For example, the smaller the particle size, the more the alloy reaction and diffusion proceed at low temperatures. Therefore, the particle size and shape are appropriately selected taking into account the process design and the influence of thermal history on battery characteristics.

[0233] The resin used in the thermosetting conductive paste may be any resin that functions as a binder for bonding, and may be selected appropriately depending on the manufacturing process to be adopted, such as printability and applicability. Examples of the resin used in the thermosetting conductive paste include thermosetting resins. Examples of the thermosetting resin include the thermosetting resins exemplified above as materials for the terminals. Only one of these materials may be used as the thermosetting resin, or two or more of these materials may be used in combination.

[0234] Furthermore, among the batteries according to embodiment 1 or each of the variations of embodiment 1, batteries not described in detail above can also be formed by applying the same method as above depending on the shape and number of components of each battery.

[0235] (Embodiment 2) Next, a description will be given of embodiment 2. In the following description of embodiment 2, differences from embodiment 1 and the modifications of embodiment 1 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0236] Fig. 11 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to embodiment 2. Specifically, Fig. 11(a) is a cross-sectional view of a battery 110 according to this embodiment, and Fig. 11(b) is a plan view of the battery 110 as seen from below in the z-axis direction. Fig. 11(a) shows a cross section taken along line XIa-XIa in Fig. 11(b).

[0237] 11 , the battery 110 according to the second embodiment differs from the battery 102 according to the second modification of the first embodiment in that the battery 110 does not include a counter electrode terminal 90. That is, the battery 110 includes a power generating element 1, a first insulating film 70, an electrode terminal 80, and a second insulating film 75.

[0238] In the battery 110, the opening 77 formed in the second insulating film 75 exposes the counter electrode principal surface 3 (specifically, the counter electrode current collector 21) to the outside. This allows the portion of the counter electrode principal surface 3 exposed by the opening 77 to be bonded to a substrate or the like. Therefore, as in the first embodiment, current can be extracted from the power generating element 1, whose layers are constrained by the first insulating film 70, using the electrode terminal 80 and the portion of the counter electrode principal surface 3 exposed by the opening 77. Furthermore, by bonding the electrode terminal 80 and the portion of the counter electrode principal surface 3 exposed by the opening 77 of the battery 110 to a substrate, the battery 110 has particularly excellent resistance to bending. Furthermore, because the battery 110 does not include a counter electrode terminal, defects such as peeling of the counter electrode terminal do not occur. Furthermore, the battery 110 can be manufactured based on the battery manufacturing methods according to the first embodiment and each of the modifications described above. However, simply forming the opening 77 in the second insulating film 75 provides a portion of the battery 110 that can be bonded to a substrate, thereby enabling the battery 110 to be manufactured with high productivity.

[0239] 11, the shape of opening 77 in a plan view is circular, but is not particularly limited thereto and may be a shape other than circular, such as rectangular, elliptical, polygonal, etc. Furthermore, opening 77 may be a slit formed so as to divide second insulating film 75 into two or more parts.

[0240] The size and position of the opening 77 in plan view can be the same as those described for the counter electrode terminal 90 in the first embodiment, for example.

[0241] Battery 110 may be mounted on substrate 60, similar to Variation 10 of Embodiment 1. Fig. 12 is a cross-sectional view showing a schematic configuration of another battery according to the present embodiment. As shown in Fig. 12, battery 111 further includes a connection portion 45 and substrate 60 in addition to the configuration of battery 110.

[0242] In the battery 111 , the second insulating film 75 is located between the counter electrode layer 20 and the substrate 60 .

[0243] The connection part 45 electrically connects the counter electrode layer 20 and the counter electrode connecting part 62. The connection part 45 is made of a conductive member such as solder or conductive resin. The connection part 45 is in contact with the counter electrode main surface 3 and the counter electrode connecting part 62. The connection part 45 joins the portion of the counter electrode main surface 3 exposed by the opening 77 to the counter electrode connecting part 62. In other words, the counter electrode connecting part 62 is joined to the portion of the counter electrode main surface 3 exposed by the opening 77 via the connection part 45, and is electrically connected to the counter electrode layer 20.

[0244] In this way, the battery 111 also has a substrate 60 that is joined to the power generating element 1 via the electrode terminal 80 and the portion of the counter electrode main surface 3 exposed by the opening 77, thereby achieving the same effect as the battery 109 according to the ninth variant of the first embodiment.

[0245] (Embodiment 3) The following describes embodiment 3. In the following description of embodiment 3, differences from embodiment 1, each modification of embodiment 1, and embodiment 2 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0246] Fig. 13 is a cross-sectional view and a plan view showing a schematic configuration of a stacked battery according to embodiment 3. Specifically, Fig. 13(a) is a cross-sectional view of a stacked battery 112 according to this embodiment, and Fig. 13(b) is a plan view of the stacked battery 112 as seen from below in the z-axis direction. Fig. 13(a) shows a cross section taken along line XIIIa-XIIIa in Fig. 13(b).

[0247] As shown in FIG. 13 , the stacked battery 112 according to the third embodiment includes a battery 100, a battery 100m, and a connection layer 41. The battery 100 is an example of a first battery, and the battery 100m is an example of a second battery. The battery 100m has the same configuration as the battery 100 except that it does not include a counter electrode terminal 90. The stacked battery 112 includes the battery 100 and the battery 100m stacked together to form a stacked battery in which multiple power-generating elements 1 are stacked.

[0248] In the example shown in FIG. 13 , two power generating elements 1 are stacked, but the number may be two or more. The multiple power generating elements 1 are stacked such that the electrode principal surfaces 2 of adjacent power generating elements 1 are adjacent to each other with a connecting layer 41 interposed therebetween, without a power generating element 1 sandwiched between them. In other words, adjacent power generating elements 1 are stacked such that the electrode principal surface 2 and the counter electrode principal surface 3 of each power generating element 1 are upside down. This allows the power generating elements 1 of the stacked battery 112 to be connected in parallel. In this way, in the stacked battery 112, multiple battery cells 50 are stacked and electrically connected in parallel. Furthermore, by configuring a parallel-connected stacked battery 112 from a battery 100 and a battery 100m that are provided with the same power generating element 1, production controllability and productivity are improved.

[0249] The connection layer 41 is made of, for example, an electrically conductive material having electron conductivity. This electrically connects current collectors of the same polarity, making it easier to extract current from the power generating element 1. The conductive material that makes up the connection layer 41 is not particularly limited, but the conductive materials exemplified in the description of the terminals above can be used as the conductive material. The connection layer 41 may also be an electrical insulator. The connection layer 41 may also be made of, for example, a resin or the like exemplified in the description of the insulating film above. The stacked battery 112 may not have the connection layer 41.

[0250] In the stacked battery 112, one or more batteries 100m are stacked on the electrode main surface 2 of the battery 100. Therefore, in the stacked battery 112, the battery 100 equipped with the counter electrode terminal 90 is arranged in the bottom layer. This allows the stacked battery 112 to be easily mounted on a substrate.

[0251] In the example shown in FIG. 13 , battery 100m has the same configuration as battery 100 except that it does not include a counter electrode terminal 90, but this is not limited thereto. For example, stacked battery 112 may include battery 100 instead of battery 100m. Furthermore, as long as the stacked battery 112 is configured such that battery 100 is arranged in the lowest layer, there are no particular restrictions on the other batteries stacked thereon, and any battery other than battery 100m may be used as long as it includes a power generation element. Furthermore, electrode terminal 80 of battery 100 and electrode terminal 80 of battery 100m may be formed separately or integrally.

[0252] The stacked battery 112 can be manufactured by joining, via a connection layer 41, the batteries 100 and 100m manufactured based on the battery manufacturing methods according to the first embodiment and the modifications described above, for example.

[0253] In this way, the stacked battery 112 includes the battery 100 according to embodiment 1 and the battery 100m that includes the first insulating film 70 like the battery 100, and therefore provides the same effects as in embodiment 1. Furthermore, by connecting multiple power generating elements 1 in parallel, a large-capacity stacked battery 112 can be realized.

[0254] The stacked battery 112 may include the battery according to any of the modifications of the first embodiment or the second embodiment, instead of the battery 100 according to the first embodiment.

[0255] (Other embodiments) While the battery and stacked battery according to the present disclosure have been described above based on embodiments and modifications, the present disclosure is not limited to these embodiments and modifications. As long as they do not deviate from the gist of the present disclosure, various modifications that would occur to a person skilled in the art and other forms constructed by combining some of the components of the embodiments are also included within the scope of the present disclosure.

[0256] For example, in the seventh modification of the first embodiment, a plurality of battery cells are electrically connected in series and stacked, and in the third embodiment, a plurality of battery cells are electrically connected in parallel, but this is not limiting. A stacked battery may be realized by combining a battery or stacked battery in which a plurality of battery cells are electrically connected in series with a battery or stacked battery in which a plurality of battery cells are electrically connected in parallel.

[0257] Furthermore, for example, in the above-described embodiment and modified examples, the counter electrode terminal entirely overlaps with the counter electrode main surface in a plan view, but this is not limited thereto. A part of the counter electrode terminal may protrude from the counter electrode terminal in a plan view.

[0258] Furthermore, the above-described embodiments can be modified, replaced, added, omitted, and the like in various ways within the scope of the claims or their equivalents. [Industrial Applicability]

[0259] The battery and stacked battery according to the present disclosure can be used, for example, as a secondary battery such as an all-solid-state battery used in various electronic devices or automobiles. [Explanation of symbols]

[0260] 1. 1g power generation element 2, 2g electrode main surface 3, 3g Counter electrode principal surface 6, 6g 1st side 7, 7g 2nd side 10 electrode layer 11 Electrode current collector 12 Electrode active material layer 20 Opposite Layer 21 Counter electrode current collector 22 Counter electrode active material layer 30 Solid electrolyte layer 40, 41 Connection layer 45 Connection 50 battery cells 60 boards 61 Electrode connection part 62 Counter electrode connection part 63 Insulator Layer 70, 70c, 70g First insulating film 71, 71g First side covering part 72, 72c, 72g 1st main surface covering part 75, 75f, 75h Second insulating film 77 Aperture 80, 80d, 80g electrode terminal 81, 81g Second side covering part 82, 82d, 82g Electrode contact parts 83, 83g 2nd main surface covering part 84 End 85 Electrode solder layer 90, 90a, 90e Counter electrode terminal 91 Outer edge 95 Counter electrode solder layer 100, 100m, 101, 102, 103, 104, 105, 106, 107, 108, 108A, 109, 110, 111 Battery 112 Stacked battery

Claims

1. A battery, a power generating element having at least one battery cell including an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer; a first insulating film; an electrode terminal electrically connected to the electrode layer; a counter electrode terminal electrically connected to the counter electrode layer; Equipped with the power-generating element has an electrode principal surface which is a principal surface formed by the surface of the electrode layer, a counter electrode principal surface which faces the electrode principal surface and is a principal surface formed by the surface of the counter electrode layer, and a side surface which connects the electrode principal surface and the counter electrode principal surface, the first insulating film has a first side surface covering portion that covers the side surface, and a first main surface covering portion that is connected to the first side surface covering portion and covers the counter electrode main surface, the electrode terminal has a second side surface covering portion that covers the first side surface covering portion, and an electrode contact portion that is connected to the second side surface covering portion and joined to the electrode main surface, the counter electrode terminal is joined to the counter electrode main surface, the electrode terminal further includes a second main surface covering portion connected to the second side surface covering portion and covering the first main surface covering portion, the battery further includes a substrate disposed opposite the counter electrode main surface, the counter electrode terminal is located between the substrate and the counter electrode layer, The substrate is an electrode connection portion joined to the electrode terminal and electrically connected to the electrode layer; a counter electrode connecting portion joined to the counter electrode terminal and electrically connected to the counter electrode layer, battery.

2. A power generating element having at least one battery cell including an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer; a first insulating film; an electrode terminal electrically connected to the electrode layer; a counter electrode terminal electrically connected to the counter electrode layer; Equipped with the power-generating element has an electrode principal surface which is a principal surface formed by the surface of the electrode layer, a counter electrode principal surface which faces the electrode principal surface and is a principal surface formed by the surface of the counter electrode layer, and a side surface which connects the electrode principal surface and the counter electrode principal surface, the first insulating film has a first side surface covering portion that covers the side surface, and a first main surface covering portion that is connected to the first side surface covering portion and covers the counter electrode main surface, the electrode terminal has a second side surface covering portion that covers the first side surface covering portion, and an electrode contact portion that is connected to the second side surface covering portion and joined to the electrode main surface, the counter electrode terminal is joined to the counter electrode main surface, the electrode terminal further includes a second main surface covering portion connected to the second side surface covering portion and covering the first main surface covering portion, the first insulating film covers the end of the electrode terminal; battery.

3. A power generating element having at least one battery cell including an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer; a first insulating film; an electrode terminal electrically connected to the electrode layer; a counter electrode terminal electrically connected to the counter electrode layer; Equipped with the power-generating element has an electrode principal surface which is a principal surface formed by the surface of the electrode layer, a counter electrode principal surface which faces the electrode principal surface and is a principal surface formed by the surface of the counter electrode layer, and a side surface which connects the electrode principal surface and the counter electrode principal surface, the first insulating film has a first side surface covering portion that covers the side surface, and a first main surface covering portion that is connected to the first side surface covering portion and covers the counter electrode main surface, the electrode terminal has a second side surface covering portion that covers the first side surface covering portion, and an electrode contact portion that is connected to the second side surface covering portion and joined to the electrode main surface, the counter electrode terminal is joined to the counter electrode main surface, the electrode terminal further includes a second main surface covering portion connected to the second side surface covering portion and covering the first main surface covering portion, the side surface includes a first side surface and a second side surface opposite to the first side surface, the first insulating film covers the first side surface and the second side surface; battery.

4. The counter electrode terminal has a plate shape and is entirely overlapped with the counter electrode main surface in a plan view. The battery according to any one of claims 1 to 3.

5. A plurality of the counter electrode terminals are provided. The battery according to any one of claims 1 to 4.

6. At least one of the electrode terminal and the counter electrode terminal contains a conductive resin. The battery of any one of claims 1 to 5.

7. an electrode solder layer covering the electrode terminal and containing solder as a main component; A counter electrode solder layer covering the counter electrode terminal and containing solder as a main component is further provided. The battery of any one of claims 1 to 6.

8. The electrode solder layer and the counter electrode solder layer are each composed of a solder plating film. The battery of claim 7.

9. the solder plating film includes a nickel plating base film and a tin plating film formed on the nickel plating base film; The battery of claim 8.

10. a second insulating film covering a part of the counter electrode main surface, the second insulating film covers an outer periphery of the counter electrode terminal in a plan view; The battery of any one of claims 1 to 9.

11. an outer peripheral edge portion of the counter electrode terminal in a plan view is sandwiched between the counter electrode main surface and the second insulating film; The battery of claim 10.

12. a power generating element having at least one battery cell including an electrode layer, a counter electrode layer, and a solid electrolyte layer located between the electrode layer and the counter electrode layer; a first insulating film; A second insulating film; an electrode terminal electrically connected to the electrode layer; Equipped with the power-generating element has an electrode principal surface which is a principal surface formed by the surface of the electrode layer, a counter electrode principal surface which faces the electrode principal surface and is a principal surface formed by the surface of the counter electrode layer, and a side surface which connects the electrode principal surface and the counter electrode principal surface, the first insulating film has a first side surface covering portion that covers the side surface, and a first main surface covering portion that is connected to the first side surface covering portion and covers the counter electrode main surface, the second insulating film covers the counter electrode main surface, an opening exposing a portion of the counter electrode principal surface is formed in the second insulating film; the electrode terminal has a second side surface covering portion that covers the first side surface covering portion, and an electrode contact portion that is connected to the second side surface covering portion and joined to the electrode main surface, the electrode terminal further includes a second main surface covering portion connected to the second side surface covering portion and covering the first main surface covering portion, The first insulating film and the second insulating film are connected to each other. battery.

13. Further, a substrate is provided which is disposed opposite to the counter electrode main surface, the second insulating film is located between the substrate and the counter electrode layer, The substrate is an electrode connection portion joined to the electrode terminal and electrically connected to the electrode layer; a counter electrode connecting portion joined to a portion of the counter electrode principal surface exposed by the opening and electrically connected to the counter electrode layer, The battery of claim 12.

14. The first insulating film and the second insulating film are connected to each other.

12. The battery according to claim 10 or 11.

15. the second insulating film contains a resin; 15. The battery of any one of claims 10 to 14.

16. In a plan view, the length of the electrode contact portion from the side surface is longer than the length of the second principal surface covering portion from the side surface.

16. The battery of any one of claims 1 to 15.

17. the first insulating film contains a resin; 17. The battery of any one of claims 1 to 16.

18. the at least one battery cell is a plurality of battery cells; The plurality of battery cells are electrically connected in series and stacked.

18. The battery of any one of claims 1 to 17.

19. The solid electrolyte layer contains a solid electrolyte having lithium ion conductivity.

19. The battery of any one of claims 1 to 18.

20. a first battery and one or more second batteries stacked on the first battery; The first battery is a battery according to any one of claims 1 to 19, The one or more second batteries are stacked on the electrode main surfaces of the first battery. Stacked battery.

Images