Battery and method for manufacturing the same

Abstract

To provide a highly reliable battery and a method for manufacturing the same.SOLUTION: A battery of the present disclosure includes a power generating element 400 including: a first electrode layer 100; a second electrode layer 200; and a solid electrolyte layer 300 disposed between the first electrode layer 100 and the second electrode layer 200. The first electrode layer 100 includes: a first active material layer 120; a first current collector layer 110 disposed on a main surface of the first active material layer 120; and a first insulating layer 130 covering at least part of a first side surface of the first current collector layer 110. The second electrode layer 200 includes: a second active material layer 220; a second current collector layer 210 disposed on a main surface of the second active material layer 220; and a second insulating layer 230 covering at least part of a second side surface of the second current collector layer 210. The first insulating layer 130 and the first current collector layer 110 include a first glass component.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] For the purpose of miniaturization and high performance of batteries, technologies related to battery lamination and surface mounting compatibility are in demand. As technologies related to such batteries, for example, Patent Document 1 and Patent Document 2 disclose batteries in which a glass component is contained in a current collector layer to reduce structural defects and interfacial resistance. Also, as a technology related to battery lamination and surface mounting compatibility, terminal electrodes are known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a highly reliable battery.

Means for Solving the Problems

[0005] The battery of the present disclosure includes a power generation element including a first electrode layer, a second electrode layer, and a solid electrolyte layer disposed between the first electrode layer and the second electrode layer, the first electrode layer including a first active material layer, a first current collector layer disposed on a main surface of the first active material layer, and a first insulating layer covering at least a part of a first side surface of the first current collector layer. The second electrode layer includes a second active material layer, a second current collector layer disposed on the main surface of the second active material layer, and a second insulating layer covering at least a part of the second side surface of the second current collector layer. The first insulating layer and the first current collector layer contain a first glass component.

Advantages of the Invention

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

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present disclosure will be specifically described with reference to the drawings.

[0009] Note that all of the embodiments described below show comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, manufacturing processes, order of manufacturing processes, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. In addition, among the components in the following embodiments, components not described in the independent claims indicating the most general concept are described as optional components.

[0010] Also, each figure is not necessarily drawn precisely. In each figure, substantially the same configurations are denoted by the same reference numerals, and duplicate explanations are omitted or simplified.

[0011] Also, in this specification and the drawings, the x-axis, y-axis, and z-axis indicate the three axes of a three-dimensional orthogonal coordinate system. In each embodiment, the z-axis direction is taken as the thickness direction of the battery. Also, in this specification, the "thickness direction" means the direction perpendicular to the plane on which the respective layers in the battery are laminated.

[0012] Also, in this specification, "plan view" means the case of viewing the battery along the lamination direction of the respective layers in the battery, and "thickness" in this specification means the length in the lamination direction of the battery, the power generation element, and each layer, unless otherwise specified.

[0013] In this specification, unless otherwise specified, in the battery, the power generation element, and each layer, "side surface" means the surface along the lamination direction of the respective layers in the power generation element, and "main surface" means the surface other than the side surface.

[0014] Also, in this specification, "inner" and "outer" in "inner side" and "outer side" etc. mean that when viewing the battery along the lamination direction of the respective layers in the power generation element, the center side of the battery is "inner" and the peripheral side of the battery is "outer".

[0015] Also, in this specification, the terms "upper" and "lower" in the configuration of the battery do not refer to the upward direction (vertically upward) and downward direction (vertically downward) in the absolute spatial recognition, but are used as terms defined by the relative positional relationship based on the lamination order in the laminated configuration. Also, the terms "upper" and "lower" are applicable not only when two components are spaced apart from each other and there is another component between the two components, but also when two components are in close contact with each other and the two components are in contact.

[0016] [Overview of the Battery] First, the battery according to this embodiment will be described.

[0017] The battery according to this embodiment includes a power generation element including a first electrode layer, a solid electrolyte layer, and a second electrode layer in this order. The first electrode layer includes a first current collector layer, a first active material layer, and a first insulating layer. The second electrode layer includes a second current collector layer, a second active material layer, and a second insulating layer. The first insulating layer covers at least a part of the first side surface of the first current collector layer. The second insulating layer covers at least a part of the second side surface of the second current collector layer.

[0018] The first insulating layer and the first current collector layer contain a first glass component.

[0019] With the above configuration, in the battery according to this embodiment, the side surface of the first current collector layer is covered by a dense first insulating layer containing an inorganic material excellent in barrier properties such as gas and moisture and high-temperature stability. Therefore, according to the battery of this embodiment, a battery excellent in environmental resistance such as gas resistance, moisture resistance, and temperature resistance can be realized. In addition, since the side surface of the first current collector layer can be protected by the first insulating layer having excellent mechanical strength, according to the battery of this embodiment, a battery excellent in impact resistance can also be realized. As described above, the battery according to this embodiment has high reliability.

[0020] Further, according to the battery of this embodiment, when connecting a lead-out terminal electrode such as a side electrode to the power generation element, the presence of the first insulating layer and the second insulating layer makes it difficult for the terminal electrode electrically connected to the first electrode layer to contact the second electrode layer, and it becomes difficult for the terminal electrode electrically connected to the second electrode layer to contact the first electrode layer. Therefore, the battery according to this embodiment is suitable for a highly reliable battery with short-circuit suppression.

[0021] In this specification, the "first side surface of the first current collector layer" means the side surface of the first current collector layer where the first insulating layer exists. The "second side surface of the second current collector layer" means the side surface of the second current collector layer where the second insulating layer exists. Also, in this specification, the side surface of the battery where the first side surface of the first current collector layer exists is referred to as the first side surface of the battery, and the side surface of the battery where the second side surface of the second current collector layer exists is referred to as the second side surface of the battery.

[0022] The first insulating layer may cover the entire first side surface of the first current collector layer. The second insulating layer may cover the entire second side surface of the second current collector layer.

[0023] The positions of the first side surface and the second side surface are not particularly limited. For example, the first side surface of the first current collector layer and the second side surface of the second current collector layer may face each other. According to the above configuration, a battery with excellent environmental resistance and shock resistance, and with short - circuit suppressed and high reliability can be realized. The first side surface of the first current collector layer and the second side surface of the second current collector layer may be perpendicular to each other.

[0024] The second insulating layer may contain at least one selected from the group consisting of an oxide of a metal contained in the second current collector layer and a second glass component. The second insulating layer and the second current collector layer may contain a second glass component.

[0025] With the above configuration, in the battery according to the present embodiment, the side surface of the second current collector layer is covered by a dense second insulating layer containing an inorganic material excellent in barrier properties such as gas and moisture, and high - temperature stability. Therefore, according to the battery of the present embodiment, a battery with more excellent environmental resistance such as gas resistance, moisture resistance, and temperature resistance can be realized. Also, since the side surfaces of the first current collector layer and the second current collector layer are each protected by the first insulating layer and the second insulating layer excellent in mechanical strength, according to the battery of the present embodiment, a battery with excellent shock resistance can be realized. As described above, the battery according to the present embodiment has high reliability.

[0026] The first glass component and the second glass component may have different compositions from each other. The first glass component and the second glass component may have different glass softening points from each other.

[0027] The first current collector layer includes a first metal sintered body portion, and the first metal sintered body portion may contain a first glass component. The first insulating layer may cover at least a part of the side surface of the first metal sintered body portion. According to such a configuration, a battery with high reliability can be realized. The first current collector layer may include a first metal sintered body portion and a first metal foil portion.

[0028] The battery of the present embodiment may further include at least one selected from the group consisting of a first side electrode and a second side electrode. The first side electrode is electrically connected to the second electrode layer and is in contact with the first electrode layer via the first insulating layer. The second side electrode is electrically connected to the first electrode layer and is in contact with the second electrode layer via the second insulating layer. According to the above configuration, while suppressing short circuit, the side electrodes respectively connected to the first electrode layer and the second electrode layer can be integrated, and a small and highly reliable battery can also be realized. The first side electrode is arranged, for example, so as to cover the entire side surface of the power generation element on the first side of the battery. The second side electrode is arranged, for example, so as to cover the entire side surface of the power generation element on the second side of the battery.

[0029] The battery of the present embodiment may include a first side electrode and a second side electrode. By providing the first side electrode and the second side electrode, surface mounting can be supported. Further, when a plurality of power generation elements are stacked to form a stacked battery, the power generation elements can be connected to each other by the first side electrode and the second side electrode. Therefore, according to the battery according to the present embodiment, a large-capacity battery that can support surface mounting and is applicable to a stacked battery and has excellent reliability can also be realized.

[0030] [First Embodiment] Hereinafter, as an example of a configuration of a battery according to the first embodiment, a battery including a power generation element including a first electrode layer, a second electrode layer, and a solid electrolyte layer, a first side electrode, and a second side electrode will be described, in which the first current collector layer is composed of a first metal foil portion and a first metal sintered body portion.

[0031] FIG. 1 is a cross-sectional view and a plan view showing a schematic configuration of a battery 1000 according to the first embodiment.

[0032] FIG. 1(a) shows a cross-sectional view of a battery 1000 according to the first embodiment. FIG. 1(b) is a plan view of the battery 1000 according to the first embodiment as viewed from above in the z-axis direction. FIG. 1(a) shows a cross-section at the position indicated by the line I-I in FIG. 1(b).

[0033] As shown in FIG. 1, the battery 1000 includes a power generation element 400 which is a laminate including a first electrode layer 100, a solid electrolyte layer 300, and a second electrode layer 200 in this order. The first electrode layer 100 includes a first active material layer 120, a first current collector layer 110 disposed on the main surface of the first active material layer 120, and a first insulating layer 130 covering at least a part of the first side surface 11 of the first current collector layer 110. The second electrode layer 200 includes a second active material layer 220, a second current collector layer 210 disposed on the main surface of the second active material layer 220, and a second insulating layer 230 covering at least a part of the second side surface 22 of the second current collector layer 210.

[0034] As shown in FIG. 1, the first side surface 11 of the first current collector layer 110 and the second side surface 22 of the second current collector layer 210 face each other. That is, the battery 1000 includes a first side surface 10 and a second side surface 20 facing the first side surface 10. Here, in this specification, the main surface on the first electrode layer 100 side of the battery 1000 is referred to as the first main surface, and the main surface facing the first main surface is referred to as the second main surface. For the power generation element 400 and each layer constituting the battery 1000, the main surface on the first main surface side of the battery 1000 is referred to as the first main surface, and the main surface on the second main surface side of the battery 1000 is referred to as the second main surface.

[0035] The first electrode layer 100 is composed of a first current collector layer 110, a first active material layer 120 disposed in contact with the second main surface 32 of the first current collector layer 110, and a first insulating layer 130. The second electrode layer 200 is composed of a second current collector layer 210, a second active material layer 220 disposed in contact with the first main surface 41 of the second current collector layer 210, and a second insulating layer 230. In the power generation element 400, the first current collector layer 110, the first active material layer 120, the solid electrolyte layer 300, the second active material layer 220, and the second current collector layer 210 are laminated in this order.

[0036] As shown in FIG. 1, the first insulating layer 130 covers the entire first side surface 11 of the first current collector layer 110 and a part of the first main surface 31 of the first current collector layer 110. That is, the first insulating layer 130 covers the surface of the first current collector layer 110 so as to wrap around from the first side surface 11 to a part of the first main surface 31.

[0037] As shown in FIG. 1, the second insulating layer 230 covers the entire second side surface 22 of the second current collector layer 210 and a part of the second main surface 42 of the second current collector layer 210. That is, the second insulating layer 230 covers the surface of the second current collector layer 210 so as to wrap around from the second side surface 22 to a part of the second main surface 42.

[0038] In the battery 1000, the first current collector layer 110 is composed of a first metal foil portion 110a and a first metal sintered body portion 110b. The first current collector layer 110 is plate-shaped. In the battery 1000, the first metal foil portion 110a and the first metal sintered body portion 110b are located in the same plane as each other. The first metal sintered body portion 110b is disposed at a position on the first side surface 11 side in the first current collector layer 110, and the first metal foil portion 110a is disposed at a position on the second side surface side in the first current collector layer 110. Therefore, the side surface of the first metal sintered body portion 110b is covered by the first insulating layer 130. The first metal foil portion 110a and the first metal sintered body portion 110b are in contact with each other.

[0039] The battery 1000 further includes a first side electrode 500 that is electrically connected to the second electrode layer 200 and in contact with the first electrode layer 100 via the first insulating layer 130, and a second side electrode 600 that is electrically connected to the first electrode layer 100 and in contact with the second electrode layer 200 via the second insulating layer 230. The first side electrode 500 is electrically connected to the second electrode layer 200 without being electrically connected to the first electrode layer 100. The second side electrode 600 is electrically connected to the first electrode layer 100 without being electrically connected to the second electrode layer 200. The first side electrode 500 covers a part of the surface of the first insulating layer 130, and the second side electrode 600 covers a part of the surface of the second insulating layer 230. Due to the presence of the first insulating layer 130, the first side electrode 500 and the first electrode layer 100 can be electrically separated. Due to the presence of the second insulating layer 230, the second side electrode 600 and the second electrode layer 200 can be electrically separated. As described above, in the battery 1000, short circuits are suppressed.

[0040] The first electrode layer 100 may be a positive electrode, and the second electrode layer 200 may be a negative electrode. Specifically, the first current collector layer 110 may be a positive current collector layer, and the first active material layer 120 may be a positive active material layer. The second current collector layer 210 may be a negative current collector layer, and the second active material layer 220 may be a negative active material layer.

[0041] In this specification, the first current collector layer 110 and the second current collector layer 210 may be collectively referred to simply as "current collector".

[0042] In this specification, the first active material layer 120 and the second active material layer 220 may be collectively referred to simply as "active material layer".

[0043] In this specification, the first side electrode 500 and the second side electrode 600 may be collectively referred to simply as "side electrode".

[0044] Hereinafter, each component of the battery 1000 will be described.

[0045] (The first current collector layer 110) The first current collector layer 110 is formed of a material having a first glass component and conductivity. The material having conductivity is, for example, a metal. The metal is, for example, aluminum (Al), iron (Fe), nickel (Ni), copper (Cu), or an alloy thereof. A conductor metal with high conductivity is preferable because it can reduce the resistance loss and heat generation of the battery. Any conductor metal that satisfies electrochemical stability and mechanical strength can be selected and used as the material of the first current collector layer 110.

[0046] The first metal foil portion 110a constituting the first current collector layer 110 can be a foil-like body, a plate-like body, or a mesh-like body made of the above metal. Further, the first metal foil portion 110a may be a laminated foil made of a plurality of metals such as a clad material.

[0047] The first metal foil portion 110a may not contain the first glass component.

[0048] The first metal sintered body portion 110b constituting the first current collector layer 110 is a sintered body of conductor metal powder and contains the first glass component. The first metal sintered body portion 110b can be formed, for example, by heat-treating a mixture containing conductor metal powder and the first glass component.

[0049] As the conductor metal powder, the metal powder of the metal described above can be used.

[0050] As the metal powder, metal powder of any shape such as spherical, elliptical, or flaky can be used. The particle diameter of the metal powder may be, for example, from 0.1 μm to 10 μm, or may be from 0.1 μm to 5 μm. When the metal powder contains powder having a fine particle diameter of, for example, 1 μm or less, the surface roughness of the first metal sintered body portion 110b decreases. As a result, the concave portions where stress concentrates are reduced, the flexural strength is improved, and the impact resistance of the first metal sintered body portion 110b is enhanced. On the other hand, when the metal powder contains powder having a large particle diameter of, for example, 3 μm or more, the particle interfaces in the first metal sintered body portion 110b are reduced, so the interface resistance is reduced, the resistance loss in the battery performance is suppressed, and the charge-discharge performance is improved.

[0051] Note that the metal powder may include a plurality of metal components and powders having different particle diameters. Thereby, the sinterability, electrochemical stability, bondability with the first metal foil portion 110a, the aforementioned flexural strength, and the interfacial resistance of the metal powder can be controlled. Therefore, the performance and reliability of the battery can be adjusted. From the viewpoint of the bondability between the first metal foil portion 110a and the first metal sintered body portion 110b, the first metal foil portion 110a and the first metal sintered body portion 110b may include a common metal component. Thereby, since the thermal expansion coefficients become close, the bondability is improved.

[0052] The first metal sintered body portion 110b can be formed, for example, using a paste containing metal powder, glass component, solvent, binder, plasticizer, etc. The shape and thickness of the first metal sintered body portion 110b can be arbitrarily controlled by controlling the properties of the above paste and the printing conditions. The printing conditions are, for example, a screen or a metal mask. The thickness is, for example, from 0.1 μm to 20 μm for a single layer. The first metal sintered body portion 110b may be thickened by repeatedly printing and film-forming. Also, by printing different metal conductors during formation, the first metal sintered body portion 110b may include a laminated film in which a plurality of metal layers are laminated. Also, in the first metal sintered body portion 110b, different metal conductor materials can be arranged in a pattern on the same plane. Thus, by including a plurality of metal conductors in the first metal sintered body portion 110b as a laminated film and a plurality of patterns, the electrochemical stability and thermal shock resistance can be adjusted, and the battery characteristics can be improved. Note that the pattern corners may be cut like a C-plane cut or may be configured with a smooth curve without protrusions. Thereby, when transferring the printing pattern, defects such as cracking and peeling of the printing pattern generated from locations where stress is likely to concentrate, such as around the pattern corners, can be reduced. The first metal sintered body portion 110b can be formed, for example, by heat-treating the above paste printed on the first active material layer 120 and sintering the metal powder.

[0053] The first metal foil portion 110a and the first metal sintered body portion 110b may have the same thickness as each other. The first metal sintered body portion 110b may be thinner or thicker than the first metal foil portion 110a. By controlling the thickness of the first metal sintered body portion 110b and adjusting the thickness relationship with the first metal foil portion 110a, warping of the first electrode layer 100 due to expansion and contraction during charge and discharge and thermal cycling can be suppressed. According to the above, structural defects such as peeling and cracking can be suppressed, so that a highly reliable battery can be obtained.

[0054] The first metal sintered body portion 110b contains a first glass component. As the first glass component, for example, various known glass frit powders having a glass softening point of 300°C to 900°C can be used. The first glass component can be, for example, a chalcogenide-based, Bi2O3 - B2O3 - ZnO - SiO2-based, PbO - B2O3-based, PbO - B2O3 - SiO2-based, etc. The softening point of the chalcogenide-based is 200°C to 500°C depending on the composition system, the softening point of the Bi2O3 - B2O3 - ZnO - SiO2-based is 400°C to 550°C, the softening point of the PbO - B2O3-based is 300°C to 350°C, and the softening point of the PbO - B2O3 - SiO2-based is 500°C to 600°C. Note that the first glass component may have an arbitrary softening point and an arbitrary viscosity in a softened state as long as it can exude onto the surface of the power generation element 400 during sintering of the metal powder in the formation of the first metal sintered body portion 110b.

[0055] The first metal sintered body portion 110b may contain a plurality of glass components. The first metal sintered body portion 110b may be formed using a plurality of different glass frit powders. Thereby, the sinterability of the metal powder when the first metal sintered body portion 110b is formed, the degree of exudation of the glass component, and the wettability of the glass component with the metal powder or the metal sintered body can be adjusted according to metal materials having various compositions and particle physical properties.

[0056] In the first metal sintered body portion 110b, the content of the glass component with respect to the metal powder is, for example, from 0.5% by mass to 10% by mass. In the first metal sintered body portion 110b, the content of the first glass component with respect to the metal powder is, for example, from 0.5% by mass to 10% by mass. In view of the conductivity of the first metal sintered body portion 110b, the sinterability of the metal powder, and the insulation coating state by the first insulating layer 130, it can be set to an appropriate content.

[0057] The particle size of the glass frit powder used is not particularly limited. For example, the particle size of the glass frit powder may be from 0.1 μm to 10 μm. An appropriate one may be selected from the viewpoints of the sinterability of the metal powder and the meltability of the glass by heat treatment. Further, as the shape of the glass frit powder, any shape such as spherical, elliptical, or flaky can be used.

[0058] As described above, the first metal sintered body portion 110b can be formed by heat treatment. For example, the above paste is pattern-printed, for example, with a width of 100 μm at an end on the main surface on the first active material layer 120 side of the laminate in which the first active material layer 120 and the solid electrolyte layer 300 are laminated, and further heat-treated, so that the metal powder particles form a sintered structure that is densified while necking by heat treatment. When heat treatment is performed at a temperature equal to or higher than the softening point of the first glass component, the softened first glass component partly enters the voids of the sintered structure, and the rest exudes to the exposed surface of the first metal sintered body portion 110b, that is, the side surface of the first current collector layer 110. Note that by cooling the first glass component that has exuded to this exposed surface, the first insulating layer 130 is formed on the first side surface 11 of the first current collector layer 110.

[0059] Note that the heat treatment is performed, for example, in an inert atmosphere such as an N2 atmosphere or an Ar atmosphere, or in a reducing atmosphere containing hydrogen. The heat treatment may be carried out by adjusting the oxygen partial pressure. Thereby, selective softening of the first glass component and sintering of the metal powder can be achieved without oxidizing the first metal foil portion 110a.

[0060] The glass frit powder preferably acts as a sintering aid for the metal powder and facilitates the formation of a sintered structure of the metal powder by heat treatment. As a result, the voids in the sintered structure are reduced, making it easier for the first glass component melted during heat treatment to be discharged to the outside of the first current collector layer 110, that is, to the first side surface 11 of the first current collector layer 110. Therefore, it becomes easier to form the first insulating layer 130.

[0061] The glass softening point of the first glass component may be a temperature at which the first current collector layer 110 is not oxidized. That is, the glass softening point of the first glass component may be lower than the temperature at which the first current collector layer 110 is oxidized. The temperature at which the first current collector layer 110 is oxidized is the oxidation temperature of the metal contained in the first current collector layer 110. When the first current collector layer 110 contains a plurality of metals, the temperature at which the first current collector layer 110 is oxidized is the oxidation temperature of the metal having the lowest oxidation temperature.

[0062] The thickness of the sintered structure of the first metal sintered body portion 110b can be confirmed, for example, by mechanically polishing or ion polishing the cross-section of the first metal sintered body portion 110b and observing it with a scanning electron microscope (SEM).

[0063] (The first insulating layer 130) The first insulating layer 130 contains the first glass component. The first insulating layer 130 covers the entire first side surface 11 of the first current collector layer 110 and a part of the first main surface 31 continuous from the first side surface 11.

[0064] The first glass component is as described above for the first metal sintered body portion 110b. As described above, the first insulating layer 130 is formed, for example, by heat-treating a material containing the metal powder and the first glass component at a temperature equal to or higher than the softening point of the first glass component when the first metal sintered body portion 110b is formed, so that the first glass component exuded to the outside of the first current collector layer 110 solidifies and covers the first side surface 11 (the surface of the first metal sintered body portion 110b) of the first current collector layer 110. That is, the first insulating layer 130 is formed by the first glass component oozing out to the exposed surface of the first metal sintered body portion 110b covering the first side surface 11 of the first current collector layer 110.

[0065] The first insulating layer 130 may contain a plurality of glass components. The first insulating layer 130 may contain a plurality of different glass frit components. Thereby, the sinterability during the heat treatment when the first metal sintered body portion 110b is formed can be adjusted, and the wettability with the metal powder can be widely controlled. As a result, the density of the first insulating layer 130 can be improved.

[0066] The thickness of the first insulating layer 130 may be, for example, from 1.0 μm to 100 μm, or from 0.1 μm to 30 μm, but is not limited thereto. The thickness of the first insulating layer 130 may be any thickness as long as it can ensure insulation. Note that if the first insulating layer 130 is made too thick, it is likely to peel off from the side surface of the first current collector layer 110 due to thermal cycling, so it is set to an appropriate thickness. Here, the thickness of the first insulating layer 130 means the length from the surface of the first insulating layer 130 facing the first side surface 11 of the first current collector layer 110 to the surface constituting the surface of the power generation element 400, that is, the length in the direction perpendicular to the lamination direction of the portion covering the first side surface 11 of the first current collector layer 110 in the first insulating layer 130.

[0067] The thickness of the first insulating layer 130 can be confirmed, for example, by mechanically polishing or ion polishing the cross section of the first insulating layer 130 and observing it by SEM. The insulation resistance of the first insulating layer 130 can be confirmed, for example, by evaluating the electrical characteristics of the microstructure using a commercially available nanoprobing device used in semiconductor failure analysis.

[0068] In addition, the film quality of the first insulating layer 130 can be set by adjusting the particle diameters, composition ratios, heat treatment profiles, etc. of the metal powder and the powder of the first glass component in order to reduce structural defects such as voids and cracks.

[0069] As described above, the first insulating layer 130 can be formed by heat-treating a paste containing, for example, metal powder and powder of a first glass component to soften the first glass component and then re-solidifying the first glass component on the side surface of the first current collector layer 110. Therefore, the first insulating layer 130 can be formed by solidifying a first glass component having insulation properties such that it exhibits a DC resistance value of, for example, 1 MΩ / cm or less. Therefore, the first insulating layer 130 has a connection with the first glass component contained in the sintered metal structure constituting the first metal sintered body portion 110b and has a strong anchor effect. Therefore, the first insulating layer 130 firmly adheres to the first metal sintered body portion 110b. Such a microstructure in which the first metal sintered body portion 110b and the first insulating layer 130 are connected can be confirmed, for example, by observing a cross-section polished mechanically or by ion polishing with SEM.

[0070] (Second current collector layer 210) The second current collector layer 210 is formed of a material having conductivity. The second current collector layer 210 contains a metal. The second current collector layer 210 may be made of, for example, a plate-shaped or foil-shaped metal.

[0071] The first current collector layer 110 may contain a metal different from that of the second current collector layer 210. The metal contained in the first current collector layer 110 may have an oxidation temperature different from that of the metal contained in the second current collector layer 210. The oxidation temperature is the temperature at which a metal oxide formation reaction occurs. For the second current collector layer 210, for example, a conductor metal that is more easily oxidized than the metal contained in the first current collector layer 110 can be used. Here, when the first current collector layer 110 contains a plurality of metals, it means that the lowest oxidation temperature among the plurality of metals is different from the oxidation temperature of the metal contained in the second current collector layer 210. When the second current collector layer 210 contains a plurality of metals, it means that the lowest oxidation temperature among the plurality of metals is different from the oxidation temperature of the metal contained in the first current collector layer 110. The same applies when both the first current collector layer 110 and the second current collector layer 210 contain a plurality of metals.

[0072] Specifically, the oxidation temperature of the metal contained in the second current collector layer 210 may be a temperature at which the metal contained in the first current collector layer 110 does not oxidize. The temperature at which the second current collector layer 210 is oxidized may be a temperature at which the first glass component does not soften. That is, the glass softening point of the first glass component may be higher than the temperature at which the second current collector layer 210 is oxidized. Here, the temperature at which the second current collector layer 210 is oxidized is the oxidation temperature of the metal having the highest oxidation temperature among the metals contained in the second current collector layer 210.

[0073] The equilibrium oxygen partial pressure of the second current collector layer 210 may be lower than the equilibrium oxygen partial pressure of the first current collector layer 110. That is, the equilibrium oxygen partial pressure of the first current collector layer 110 may be greater than the equilibrium oxygen partial pressure of the second current collector layer 210. "The equilibrium oxygen partial pressure of the first current collector layer 110 is greater than the equilibrium oxygen partial pressure of the second current collector layer 210" means that at the same temperature, the equilibrium oxygen partial pressure of the metal contained in the first current collector layer 110 is greater than the equilibrium oxygen partial pressure of the metal contained in the second current collector layer 210. When the first current collector layer 110 and the second current collector layer 210 contain a plurality of metals, it means that the smallest equilibrium oxygen partial pressure among the metals in the first current collector layer 110 is greater than the smallest equilibrium oxygen partial pressure among the metals in the second current collector layer 210. The equilibrium oxygen partial pressure of a metal is a value determined for the oxide formation reaction of the metal and is the oxygen partial pressure at the boundary where the metal is oxidized or not oxidized at the treatment temperature T. The smaller the equilibrium oxygen partial pressure, the easier it is to oxidize.

[0074] At a temperature below the glass softening point of the first glass component contained in the first metal sintered body portion 110b and the first insulating layer 130, the equilibrium oxygen partial pressure of the second current collector layer 210 may be lower than the equilibrium oxygen partial pressure of the first current collector layer 110. By setting the equilibrium oxygen partial pressure relationship in this way, without causing oxidation of the first current collector layer 110, remelting of the first glass component of the first insulating layer 130, and excessive shrinkage deformation of the first metal sintered body portion 110b, the second current collector layer 210 can be heat-treated at a temperature lower than the softening point of the first glass component, and as will be described later, the second insulating layer 230 can be formed.

[0075] The metal used for the second current collector layer 210 can be selected based on the relationship between the oxidation temperature and the equilibrium oxygen partial pressure with the above-described first current collector layer 110. For example, a metal foil of a metal with excellent conductivity such as Al, Fe, Ni, Cu, or an alloy thereof can be used. Note that, in ascending order of low equilibrium oxygen partial pressure, that is, in ascending order of ease of oxidation, they are Al, Fe, Ni, and Cu. For example, when the metal contained in the first current collector layer 110 is Cu, Ni, Fe, or Al may be used for the second current collector layer 210. Thereby, even if the second current collector layer 210 is oxidized to form the second insulating layer 230 described later, the first current collector layer 110 will not be oxidized. For example, the first current collector layer 110 may contain a Cu metal foil and metal powder, and the second current collector layer 210 may be made of a Ni metal foil.

[0076] Note that the first current collector layer 110 and the second current collector layer 210 may contain the same metal material.

[0077] In order to reduce the resistance loss of the battery and, in particular, the heat generation during high-rate operation, it is preferable that the second current collector layer 210 has high conductivity. For the second current collector layer 210, a conductor can be selected in consideration of the electrochemical stability, impact resistance, and mechanical strength against impact in the manufacturing process during battery operation.

[0078] The oxidizability and equilibrium oxygen partial pressure of such metal conductors used for the first current collector layer 110 and the second current collector layer 210 can be obtained experimentally. For example, by heat-treating the metal conductor while adjusting the oxygen partial pressure PO2 by controlling the ratio of the CO2 and H2 mixed gas in the processing environment, the conditions for forming the respective metal oxides of the metal conductors used for the first current collector layer 110 and the second current collector layer 210 can be obtained. For example, when heat-treating at 700 °C, the oxygen partial pressure PO2 may be adjusted from 1×10 -10 Pa to 1×10 -4 Pa and then performing the heat treatment. Note that the metal oxide can be analyzed by subjecting the heat-treated metal conductor to elemental analysis using energy-dispersive spectroscopy (EDS) or an electron probe microanalyzer (EPMA).

[0079] (Second insulating layer 230) The second insulating layer 230 covers the second side surface 22 of the second current collector layer 210. The second insulating layer 230 may contain an oxide of a metal contained in the second current collector layer 210. Here, when the metal contained in the second current collector layer 210 is an alloy, the "oxide of the metal contained in the second current collector layer 210" means an oxide of at least one of the metal elements constituting the alloy. The second insulating layer 230 can be formed, for example, by oxidizing the second side surface 22 of the second current collector layer 210 through heat treatment in an environment with an oxygen partial pressure equal to or higher than the equilibrium oxygen partial pressure of the second current collector layer 210. The formation temperature of the above-mentioned oxide of the second insulating layer 230 may be lower than the glass softening point of the first glass component.

[0080] The heat treatment is carried out under conditions that satisfy the temperature and oxygen partial pressure at which the second current collector layer 210 is oxidized and that do not adversely affect the first current collector layer 110 and the first glass component. For example, the heat treatment is carried out at a temperature lower than the glass softening point of the first glass component so that the first glass component does not melt, and at a temperature and oxygen partial pressure at which the first current collector layer 110 is not oxidized.

[0081] On the surface of the second current collector layer 210, at locations where the second insulating layer 230 is not to be formed, a paste obtained by mixing a material with a high sintering temperature such as aluminum oxide and an organic solvent is applied in advance for resist, and then heat treatment is carried out. The resist can be removed by brushing after the heat treatment. Alternatively, after heat treatment without resist, the oxide film of the oxide obtained at unnecessary locations can also be removed by selectively removing it with a reutter or polishing. Alternatively, oxidation may be suppressed by applying an anti-rust agent to locations where the second insulating layer 230 is not to be formed and then carrying out heat treatment.

[0082] The thickness of the second insulating layer 230 may be, for example, from 0.1 μm to 30 μm. The thickness of the second insulating layer 230 may be any thickness as long as it has insulating properties and is not limited to the above numerical range. If the second insulating layer 230 is made excessively thick, it is likely to peel off from the side surface of the second current collector layer 210 due to thermal cycling, so it is set to an appropriate thickness. Here, the thickness of the second insulating layer 230 means the length from the surface of the second insulating layer 230 facing the second side surface 22 of the second current collector layer 210 to the surface constituting the surface of the power generation element 400, that is, the length in the direction perpendicular to the lamination direction of the portion covering the second side surface 22 of the second current collector layer 210 in the second insulating layer 230.

[0083] The second insulating layer 230 may be composed of a polycrystalline structure. The crystal grain size of the polycrystalline structure is, for example, from 0.3 μm to 10 μm. The crystal grain size can be controlled by adjusting the temperature, heating rate, and heat treatment time during the formation of the second insulating layer 230. The heating rate is, for example, from 10 °C / h to 100 °C / h. The heat treatment time is, for example, from 0.1 h to 10 h. For example, when the temperature is increased, the heating rate is slowed down, and the heat treatment time is lengthened, the crystal grain size tends to increase due to grain growth. A fine crystal grain size such as, for example, 3 μm or less of the second insulating layer 230 is preferable in terms of obtaining mechanical strength. Also, when the particles are of the above size, when forming a side electrode, uniform wettability when applying a paste for forming the side electrode can be obtained, which is preferable in terms of suppressing defects in the coating film.

[0084] The bonding interface between the second insulating layer 230 and the second current collector layer 210 may not be clear. The bonding interface between the second insulating layer 230 and the second current collector layer 210 may have a region where the second insulating layer 230 and the second current collector layer 210 are mixed. The above region may be, for example, from 10 μm to 200 μm. When the second insulating layer 230 is formed by oxidizing the second current collector layer 210, since oxidation proceeds from the surface of the second current collector layer 210, such a gradational region can be formed. For example, on the second side surface 22 side of the second current collector layer 210, there is a large amount of oxide of the second current collector layer 210, and as it goes from the surface of the second current collector layer 210 toward the inside of the second current collector layer 210, the amount of oxide decreases and the metal component of the second current collector layer 210 increases, showing a change with respect to the depth from the surface. When the second insulating layer 230 and the second current collector layer 210 are bonded so as to have the above gradational bonding region, compared with the case of interface bonding without the above gradational region, the anchor effects of both and, for example, stress are dispersed, so the adhesion becomes strong and the bonding reliability of the second insulating layer 230 becomes high.

[0085] The state change of the amount of oxide and metal component between the second insulating layer 230 and the second current collector layer 210, and the shape of the crystal particles of the second insulating layer 230 can be observed, for example, from the compositional mapping analysis of the cross section of the battery 1000 using EDS or EPMA.

[0086] (Active material layer) The first active material layer 120 is disposed in contact with one surface of the first current collector layer 110. The first active material layer 120 is, for example, a positive electrode active material layer.

[0087] The second active material layer 220 constitutes the second electrode layer 200 as the counter electrode of the first electrode layer 100. The second active material layer 220 is disposed in contact with one surface of the second current collector layer 210.

[0088] The positive electrode active material layer contains a positive electrode active material. The positive electrode active material layer is, for example, a layer composed of a positive electrode material containing 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 or removed into or 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 may be any material that can maintain its characteristics as a positive electrode active material in the battery manufacturing process such as heat treatment, and can be appropriately selected according to the type of the battery, and known positive electrode active materials can be used.

[0089] The positive electrode active material is, for example, a compound containing lithium and a transition metal element. Examples of the compound include an oxide containing lithium and a transition metal element, or a phosphate compound containing lithium and a transition metal element.

[0090] Examples of the oxide containing lithium and a transition metal element include x M 1-x lithium nickel composite oxides such as LiNiMO2 (where M is at least one selected from the group consisting of Co, Al, Mn, V, Cr, Mg, Ca, Ti, Zr, Nb, Mo, and W, and x satisfies 0 < x ≤ 1), layered oxides such as lithium cobalt oxide (LiCoO2) and lithium nickel oxide (LiNiO2), or lithium manganate having a spinel structure (for example, LiMn2O4, Li2MnO3, or LiMO2).

[0091] Examples of the phosphate compound containing lithium and a transition metal element include lithium iron phosphate (LiFePO4) having an olivine structure.

[0092] As the positive electrode active material, sulfides such as sulfur (S) and lithium sulfide (Li2S) may be used. In this case, lithium niobate (LiNbO3) or the like may be coated on or added to the positive electrode active material particles.

[0093] For the positive electrode active material, only one of these materials may be used, or two or more of these materials may be used in combination.

[0094] In addition to the positive electrode active material, the positive electrode active material layer may contain materials other than the positive electrode active material. That is, the positive electrode active material layer may be a composite layer composed of a composite of the positive electrode active material and other materials. The other materials are, for example, solid electrolytes such as inorganic solid electrolytes and sulfide solid electrolytes, conductive aids such as acetylene black, or binders for binding such as polyethylene oxide and polyvinylidene fluoride. By mixing the positive electrode active material and other materials such as solid electrolytes at a predetermined ratio, the lithium ion conductivity in the positive electrode active material layer can be improved, and the electron conductivity can also be improved.

[0095] The positive electrode active material layer may have a thickness of, for example, 5 μm or more and 300 μm or less.

[0096] The negative electrode active material layer contains a negative electrode active material.

[0097] The negative electrode active material layer is, for example, a layer composed of a negative electrode material containing a negative electrode active material.

[0098] The negative electrode active material refers to a substance in which metal ions such as lithium (Li) ions or magnesium (Mg) ions are inserted or removed 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 the negative electrode active material may be any material that can maintain the characteristics as the negative electrode active material in the manufacturing process of the battery such as heat treatment, and can be appropriately selected according to the type of the battery, and known negative electrode active materials can be used.

[0099] The negative electrode active material is, for example, a carbon material such as natural graphite, artificial graphite, graphite carbon fiber, and resin-fired carbon, or an alloy-based material that is made into a composite with a solid electrolyte. The alloy-based material is, for example, LiAl, LiZn, Li3Bi, Li3Cd, Li3Sb, Li4Si, Li 4.4 Pb, Li 4.4 Sn, Li0.17 C, and lithium alloys such as LiC6, titanium niobium oxide (TiNb2O7), lithium titanate (Li4Ti5O 12 ), oxides of lithium and transition metal elements such as zinc oxide (ZnO), or metal oxides such as silicon oxide (SiO x ).

[0100] As the negative electrode active material, only one of these materials may be used, or two or more of these materials may be combined and used.

[0101] The negative electrode active material layer may contain materials other than the negative electrode active material in addition to the negative electrode active material. That is, the negative electrode active material layer may be a composite layer composed of a composite of the negative electrode active material and other materials. Other materials are, for example, solid electrolytes such as inorganic solid electrolytes and sulfide solid electrolytes, conductive aids such as acetylene black, or binders for binding such as polyethylene oxide and polyvinylidene fluoride.

[0102] By mixing the negative electrode active material and other materials such as a solid electrolyte at a predetermined ratio, the lithium ion conductivity in the negative electrode active material layer can be improved, and the electron conductivity can also be improved.

[0103] The negative electrode active material layer may have a thickness of, for example, 5 μm or more and 300 μm or less.

[0104] In FIG. 1, the first active material layer 120 and the second active material layer 220 are rectangular in plan view, but are not limited thereto. The active material layer only needs to include a portion in contact with the current collector layer, and may be circular or elliptical, or may be larger or smaller than the current collector layer in contact.

[0105] (Solid electrolyte layer 300) The solid electrolyte layer 300 contains a solid electrolyte.

[0106] The solid electrolyte layer 300 contains, for example, a solid electrolyte as a main component. Here, the main component refers to the component that is most contained in the solid electrolyte layer 300 in terms of mass ratio. The solid electrolyte layer 300 may consist only of the solid electrolyte.

[0107] Note that the solid electrolyte layer 300 of the battery 1000 is disposed between the first active material layer 120 (for example, the positive electrode active material layer) and the second active material layer 220 (for example, the negative electrode active material layer), and is in contact with each of them.

[0108] The solid electrolyte may be any known solid electrolyte having ion conductivity for a battery. As the solid electrolyte, for example, a solid electrolyte that conducts metal ions such as lithium ions or magnesium ions can be used.

[0109] The type of the solid electrolyte may be appropriately selected according to the type of conductive ions. As the solid electrolyte, for example, an inorganic solid electrolyte such as an oxide solid electrolyte, a halide solid electrolyte, or a sulfide solid electrolyte can be used.

[0110] Examples of the oxide solid electrolyte include lithium-containing metal oxides such as Li7La3Zr2O 12 , Li7Pr3Zr2O 12 , Li2O - SiO2, and Li2O - SiO2 - P2O5, lithium-containing metal nitrides such as Li x P y O 1-z N z , and lithium-containing transition metal oxides such as lithium phosphate (Li3PO4) or lithium titanate oxide can be used.

[0111] The halide solid electrolyte is, for example, a compound containing Li, M, and X. Here, M is at least one selected from the group consisting of metal elements and semi-metal elements other than Li. X is at least one selected from the group consisting of F, Cl, Br, and I.

[0112] The "semi-metal elements" are B, Si, Ge, As, Sb, and Te. The "metal elements" are all the elements included in Groups 1 to 12 of the periodic table (excluding hydrogen), and all the elements included in Groups 13 to 16 of the periodic table (excluding B, Si, Ge, As, Sb, Te, C, N, P, O, S, and Se).

[0113] In order to improve the ionic conductivity of the halide solid electrolyte, M may contain Y. M may be Y.

[0114] The halide solid electrolyte is, for example, Li a Me b Y c It may be a compound represented by X6. Here, the mathematical formulas: a + mb + 3c = 6, and c > 0 are satisfied. The value of m represents the valence of Me.

[0115] In order to improve the ionic conductivity of the halide solid electrolyte, Me may be at least one selected from the group consisting of Mg, Ca, Sr, Ba, Zn, Sc, Al, Ga, Bi, Zr, Hf, Ti, Sn, Ta, and Nb.

[0116] In order to improve the ionic conductivity of the halide solid electrolyte, X may contain at least one selected from the group consisting of Cl and Br.

[0117] The halide solid electrolyte may contain at least one selected from the group consisting of Li3AlF6 and Li2TiF6.

[0118] As the sulfide solid electrolyte, for example, lithium-containing sulfides such as Li2S-P2S5 system, Li2S-SiS2 system, Li2S-B2S3 system, Li2S-GeS2 system, Li2S-SiS2-LiI system, Li2S-SiS2-Li3PO4 system, Li2S-Ge2S2 system, Li2S-GeS2-P2S5 system, or Li2S-GeS2-ZnS system can be used.

[0119] As the solid electrolyte, only one of these materials may be used, or two or more of these materials may be combined and used.

[0120] In addition to the solid electrolyte, the solid electrolyte layer 300 may contain a binder for binding such as polyethylene oxide or polyvinylidene fluoride.

[0121] The thickness of the solid electrolyte layer 300 may be, for example, 5 μm or more and 150 μm or less.

[0122] The material of the solid electrolyte may be composed of an aggregate of particles. Alternatively, the material of the solid electrolyte may be composed of a sintered structure.

[0123] (Side electrode) The first side electrode 500 covers the first side of the power generation element 400. The first side electrode 500 is in contact with the first electrode layer 100 via the first insulating layer 130. The first side electrode 500 is electrically connected to the second current collector layer 210 without being electrically in contact with the first current collector layer 110. The second side electrode 600 covers the second side of the power generation element 400. The second side electrode 600 is in contact with the second electrode layer 200 via the second insulating layer 230. The second side electrode 600 is electrically connected to the first current collector layer 110 without being electrically in contact with the second current collector layer 210. In this way, the first side electrode 500 and the second side electrode 600 are formed on the first side 10 and the second side 20 of the battery 1000, respectively. Here, the first side of the power generation element 400 means the side of the power generation element 400 on the first side 10 side of the battery 1000, and the second side of the power generation element 400 means the side of the power generation element 400 on the second side 20 side of the battery 1000.

[0124] The side electrode only needs to have electrical conductivity. For example, a conductive resin containing a metal component or a baked electrode material can be used. It is preferable that the side electrode is formed of a material with high conductivity because it can suppress the resistance loss at the connection portion between the side electrode and the current collector layer.

[0125] At least one selected from the group consisting of the first side electrode 500 and the second side electrode 600 may contain a metal sintered body. That is, at least one selected from the group consisting of the first side electrode 500 and the second side electrode 600 may contain a baked metal conductor.

[0126] At least one selected from the group consisting of the first side electrode 500 and the second side electrode 600 may contain a metal sintered body and a conductive resin, and at least a part of the surface of the metal sintered body may be coated with the conductive resin.

[0127] At least one selected from the group consisting of the first side electrode 500 and the second side electrode 600 may contain a conductive resin.

[0128] At least one selected from the group consisting of the first side electrode 500 and the second side electrode 600 may have a multilayer structure. For example, the side electrode may be a multilayer film formed by laminating a plurality of electrode materials or a plurality of metals. Such a multilayer film may include, for example, an underlayer in contact with the first insulating layer 130 or the second insulating layer 230, which generally contains a low-resistance baked electrode material, and a surface layer that may contain a soft and sealing conductive resin. By forming such a multilayer film, the connection resistance with the current collector layer can be reduced. In addition, due to the softness of the resin, the impact resistance during battery substrate mounting can be improved. Furthermore, due to the sealing property of the surface layer resin, the intrusion of moisture and gas, which are factors causing deterioration of battery characteristics, into the power generation element can be suppressed.

[0129] As the conductive resin, for example, a thermosetting resin such as an epoxy resin can be used.

[0130] The conductive resin may contain powders of common metal conductors such as Au, Ag, Cu, Al, Ni, Fe, Pd, or Pt as metal components. As the powders of the metal conductor, particles of any shape such as spherical, elliptical, or flaky can be used. The particle size of the particles is, for example, from 0.1 μm to 10 μm.

[0131] The conductive resin may further contain a low melting point metal such as Sn, Zn, Al, Au, or an alloy thereof. As a result, when the side electrode is a multilayer film as described above, a diffusion layer is formed in the surface layer of the side electrode on the baking electrode material during the thermosetting of the conductive resin, and a strong fixation can be formed, so that the mechanical reliability of the side electrode is enhanced.

[0132] The side electrode may further contain a glass component. As a result, when baking the side electrode by heat treatment, the molten glass component can seal the pores in the microstructure of the side electrode, thereby improving the sealing property of the side electrode. In addition, the glass component diffuses into the first insulating layer 130 or the second insulating layer 230, and the adhesion is strengthened. The diffusion depth of the glass component is, for example, from 0.1 μm to 30 μm.

[0133] Also, from the viewpoints of the resistance of the side electrode, the adhesion strength with the power generation element 400, and the electrochemical stability, the side electrode may contain metal particles of a plurality of shapes and further a plurality of metals. When the side electrode is a multilayer film as described above, when a diffusion layer is formed from the base layer to the first insulating layer 130 or the second insulating layer 230 by heat treatment and baking of the side electrode, the side electrode is in a state of being embedded in the first insulating layer 130 or the second insulating layer 230, and strong adhesion is obtained. At this time, the portion of the diffusion layer becomes the embedded portion. That is, at least a part of the first side electrode 500 may be embedded in the first insulating layer 130. At least a part of the second side electrode 600 may be embedded in the second insulating layer 230.

[0134] The thickness of the side electrode is, for example, from 0.5 μm to 100 μm, but is not limited thereto and may be set to any thickness. If the side electrode is excessively thin, the resistance loss becomes large. On the other hand, if the side electrode is excessively thick, it is likely to peel off from the power generation element 400 due to a thermal cycle or a thermal shock, or the weight energy density decreases. Therefore, it is set to an appropriate thickness. The thickness of the side electrode means the length from the surface facing the side of the power generation element 400 to the surface constituting the side of the battery 1000, that is, the length of the side electrode in a direction perpendicular to the stacking direction of the power generation element 400.

[0135] (Others) The battery according to the first embodiment may further include members other than those described above. For example, the battery 1000 may include an insulating layer that covers its surface. For example, the battery 1000 may further include a third insulating layer that covers at least a part of the surface of the power generation element 400.

[0136] The third insulating layer may cover the surface of the power generation element 400 except for the side surfaces where the first side electrode 500 and the second side electrode 600 of the power generation element 400 are disposed.

[0137] The third insulating layer may contain a resin. The resin may be a thermosetting resin. The thermosetting resin is, for example, an epoxy resin.

[0138] The third insulating layer may have a multilayer structure.

[0139] As shown in FIG. 1, the first electrode layer 100, the first current collector layer 110, the first active material layer 120, the solid electrolyte layer 300, the second current collector layer 210, the second active material layer 220, and the second electrode layer 200 are each rectangular in plan view, but other shapes are also acceptable.

[0140] According to the above configuration, it is possible to provide a surface-mountable battery that is small in size, large in capacity, and excellent in reliability, and a method for manufacturing the same.

[0141] When comparing the configuration of the battery 1000 according to the first embodiment with the configurations of the batteries described in Patent Document 1 and Patent Document 2, there are the following differences.

[0142] Patent Document 1 discloses an all-solid-state battery using a glass material as the material of the current collector layer. However, the current collector layer containing the glass material disclosed in Patent Document 1 is formed entirely of a material containing a glass material for the purpose of controlling the firing shrinkage behavior of the current collector layer to adjust the difference in sintering behavior with the active material layer, and improving the adhesion with the active material to reduce structural defects and junction resistance at the interface of the active material layer. In the battery described in Patent Document 1, an insulating layer that covers the side surface of the current collector layer and contains a glass component is not provided. Therefore, the battery described in Patent Document 1 is different from the battery 1000 according to the first embodiment, which includes a first insulating layer 130 that covers the first side surface 11 of the first current collector layer 110 and contains a first glass component, and a second insulating layer 230 that covers the second side surface 22 of the second current collector layer 210. Due to such a configuration, the battery 1000 according to the first embodiment can suppress the electrical contact between the current collector layer that should not be short-circuited and the terminal electrode due to the presence of the first insulating layer 130 and the second insulating layer 230, even if a terminal electrode is provided on the side surface of the power generation element 400. Furthermore, the reliability of the side electrode, such as the bonding property and the sealing property, can be enhanced. As a result, the current collector layer and the side electrode that need to be electrically connected can be selectively and electrically connected with high reliability, so that a small and highly reliable surface-mountable battery with an integrated structure can be realized. On the other hand, the battery described in Patent Document 1 will cause a problem of short-circuiting with the counter electrode current collector layer when a terminal electrode is provided. Patent Document 2 discloses a multilayer all-solid-state lithium-ion secondary battery in which a lead-out electrode is formed using a paste containing glass frit, but an insulating layer that covers the side surface of the current collector layer and contains a glass component is not provided. Therefore, the battery described in Patent Document 2 is also different from the battery 1000 according to the first embodiment, which includes a first insulating layer 130 that covers the first side surface 11 of the first current collector layer 110 and contains a first glass component, and a second insulating layer 230 that covers the second side surface 22 of the second current collector layer 210.

[0143] Hereinafter, a modified example of the battery according to the first embodiment will be described. In the description of the following modified examples, the description will focus on the differences from the embodiment, and the description of the common points will be omitted or simplified.

[0144] [Modification Example 1] The first current collector layer 110 may be configured by laminating a layered first metal foil portion and a layered first metal sintered body portion. Further, in addition to the first side surface 11 of the first current collector layer 110, the first insulating layer 130 may cover the entire first main surface 31.

[0145] FIG. 2 is a cross-sectional view and a plan view showing a schematic configuration of a first modification of the battery according to the first embodiment. FIG. 2(a) shows a cross-sectional view of the battery 1001. FIG. 2(b) is a plan view of the battery 1001 as viewed from the upper side in the z-axis direction. In FIG. 2(a), a cross-section at the position indicated by the line II-II in FIG. 2(b) is shown.

[0146] The first current collector layer 111 of the battery 1001 is a two-layer laminated film in which a plate-like first metal sintered body portion 111b obtained by sintering a metal powder and a glass powder is laminated on a plate-like first metal foil portion 111a. Further, the first insulating layer 131 of the battery 1001 covers the entire first side surface 11 and the first main surface 31 of the first current collector layer 111. Furthermore, the second insulating layer 231 of the battery 1001 covers the entire second side surface 22 and the second main surface 42 of the second current collector layer 211.

[0147] Since the surfaces of the current collectors of the battery 1001 are covered by the first insulating layer 131 and the second insulating layer 231, which are dense inorganic insulating layers, the battery has excellent environmental resistance. Note that, if necessary, the first insulating layer or the second insulating layer disposed on the main surface of the current collector layer may be polished and removed in whole or in part.

[0148] In the first current collector layer 111, the layer in contact with the main surface of the first active material layer 120 is a layer composed of a plate-shaped first metal foil portion 111a. A plate-shaped first metal sintered body portion 111b is further laminated on the layer composed of the plate-shaped first metal foil portion 111a. These two-layer laminated films are sintered and fixed. The first metal foil portion 111a may be surface roughened on both the front and back. The surface roughness Rz is, for example, from 0.3 μm to 3 μm. Thereby, the bonding property with the first active material layer 120 is enhanced. Also, the wettability with the first metal sintered body portion 111b containing glass powder is improved, and the bonding property is improved by densification due to pore reduction at the bonding interface and an increase in the bonding area, making it difficult to peel off against charge-discharge cycles and thermal cycles. High reliability is obtained. The improvement in the wettability of the first metal sintered body portion 111b can homogenize the film thickness of the first active material layer 120, so that the in-plane characteristic distribution of the first active material layer 120 is made uniform, and the battery characteristics and reliability are improved.

[0149] Similar to the battery 1000, the first current collector layer 111 may contain, for example, a Cu metal foil and metal powder, and the second current collector layer 211 may be made of, for example, a Ni metal foil.

[0150] The first current collector layer 111, which is a two-layer laminated film, can be formed, for example, as follows. A paste containing a glass component and Cu powder is applied by screen printing to a thickness of about 20 μm on the surface of a Cu metal foil with a thickness of 10 μm or less and dried to produce a laminate. Note that it is not limited to screen printing, and other production methods such as metal mask printing or inkjet may be used. By heat-treating the laminate, the first current collector layer 111 in which the first metal foil portion 111a and the first metal sintered body portion 111b are laminated is formed. By performing the above heat treatment at a temperature equal to or higher than the softening point of the first glass component, the first glass component exuded from the first metal sintered body portion 110b wets and spreads from the main surface to the side surface of the first metal foil portion 111a. In this way, a first insulating layer 131 covering the first side surface 11 of the first current collector layer 111 is formed.

[0151] Thus, by forming the first current collector layer 111 from a laminate having a two-layer structure in which a layer containing a glass component and metallic Cu powder is laminated on a Cu metal foil, in addition to the above-described effects of improving battery characteristics and reliability, further, since the metal foil restrains the shrinkage of the metal powder, shrinkage of the outer shape of the current collector layer due to heat treatment is suppressed, and thus an effect is obtained in which the first insulating layer 131 can be formed on the side surface of the first current collector layer 111 while maintaining the outer shape. Therefore, peeling of the current collector layer from the active material layer and warping of the battery 1001 due to the difference in shrinkage between the current collector layer shape and the active material layer shape are suppressed, and a highly reliable battery can be realized.

[0152] Incidentally, the thickness and composition of the compacted structure of the current collector layer may be arbitrarily set from the viewpoints of electrochemical stability, corrosion resistance, and the like.

[0153] [Modification Example 2] The first current collector layer may be configured by laminating such that the first metal sintered body portion is sandwiched between two first metal foil portions.

[0154] FIG. 3 is a cross-sectional view and a plan view showing a schematic configuration of a second modification of the battery according to the first embodiment. FIG. 3(a) shows a cross-sectional view of the battery 1002. FIG. 3(b) is a plan view of the battery 1002 as viewed from above in the z-axis direction. In FIG. 3(a), a cross-section at the position indicated by the line III-III in FIG. 3(b) is shown.

[0155] In the battery 1002, the first current collector layer 112 is a three-layer laminated film in which a plate-shaped first metal sintered body portion 112b obtained by sintering a metal powder and a glass powder is laminated on a plate-shaped first metal foil portion 112a, and a plate-shaped first metal foil portion 112c is further laminated on the first metal sintered body portion 112b. That is, the first current collector layer 112 is configured such that the first metal sintered body portion 112b is disposed between the plate-shaped first metal foil portions 112a and 112c. The first insulating layer 132 covers the first side surface 11 of the first current collector layer 112.

[0156] Similar to the battery 1000 and the battery 1001, the first current collector layer 112 may contain, for example, a Cu metal foil and metal powder, and the second current collector layer 210 may be made of, for example, a Ni metal foil.

[0157] The first current collector layer 112, which is a three-layer laminated film, can be formed, for example, by applying a paste containing a glass component and Cu powder to the surface of a Cu metal foil with a thickness of 10 μm or less at a thickness of about 20 μm or less by a method such as screen printing, drying, then laminating another Cu metal foil, pressing, and heat-treating the resulting laminate. By performing the above heat treatment at a temperature equal to or higher than the softening point of the first glass component, the first glass component exudes and spreads from the first metal sintered body portion 112b between the first metal foil portions 112a and 112c to the first side surface 11 of the first current collector layer 112. When the exuded first glass component solidifies, the first insulating layer 132 is formed on the first side surface 11 of the first current collector layer 110. The bonding interfaces of the three layers in the laminated film may be blocked with glass.

[0158] In this way, by forming the first current collector layer 112 into a three-layer structure in which the first metal sintered body portion 112b of metal powder containing a glass component is sandwiched in layers between two metal foils, the metal foil restrains the shrinkage of the metal powder, thereby suppressing the shrinkage of the outer shape of the first current collector layer 112 due to heat treatment. As a result, the first insulating layer 132 can be formed on the side surface of the first current collector layer 112 while maintaining the outer shape. Therefore, the dimensional accuracy of the first current collector layer 112 in the manufacturing process is improved, the peeling from the first active material layer 120 in the heat treatment and the warping of the battery 1002 are suppressed, and a highly reliable battery can be realized. In addition, since no extra glass component exudes from the main surface of the first current collector layer 112, the labor of polishing or resist for removing the extra glass component is reduced.

[0159] [Modification Example 3] The first current collector layer is composed of a first metal foil portion located at the central portion in the first plan view and a first metal sintered body portion present, for example, in a U-shape at its outer peripheral portion, and the first metal foil portion and the first metal sintered body portion may be present in the same plane.

[0160] FIG. 4 is a cross-sectional view and a plan view showing a schematic configuration of a third modification of the battery according to the first embodiment. FIG. 4(a) shows a cross-sectional view of the battery 1003. FIG. 4(b) is a plan view of the battery 1003 as viewed from above in the z-axis direction. In FIG. 4(a), a cross-section at the position indicated by line IV-IV in FIG. 4(b) is shown.

[0161] The battery 1003 includes a first current collector layer 113 having a first metal foil portion 113a located at the center in plan view and a U-shaped first metal sintered body portion 113b at the outer periphery. Further, in the battery 1003, a first insulating layer 133 covers the first side surface 11A of the first current collector layer 113, the first side surfaces 11B and 11C that are perpendicular to the first side surface 11A, and a part of the first main surface 31 that is continuous from the covered side surfaces. In a plan view of the battery 1003, the first insulating layer 133 is present in a U-shape. The battery 1003 is different from the battery 1000 in that the first metal sintered body portion 113b covers all side surfaces of the first metal foil portion 113a except the second side surface (the side surface on the second side surface side of the first current collector layer), and the first insulating layer 133 covers the first side surfaces 11A, 11B, and 11C of the first current collector layer 113.

[0162] According to such a configuration, the first insulating layer 133, which is a solidified glass component harder than the metal foil, acts as a skeleton structure that supports the first current collector layer 113, thereby improving the bending resistance of the first current collector layer 113 against bending stress. Therefore, the impact resistance of the battery 1003 is improved and warping can be suppressed, so that a highly reliable battery can be obtained.

[0163] [Second Embodiment] Hereinafter, as a configuration example of the battery of the second embodiment, a battery including a power generation element including a first electrode layer, a second electrode layer, and a solid electrolyte layer, a first side electrode, and a second side electrode will be described, in which the first current collector layer is composed of a first metal foil portion and a first metal sintered body portion, and the second current collector layer is composed of a second metal foil portion and a second metal sintered body portion. Matters described in the first embodiment may be omitted as appropriate.

[0164] FIG. 5 is a cross-sectional view and a plan view showing a schematic configuration of the battery 2000 according to the second embodiment.

[0165] FIG. 5(a) is a cross-sectional view of the battery 2000 according to the second embodiment. FIG. 5(b) is a plan view of the battery 2000 according to the second embodiment as viewed from above in the z-axis direction. FIG. 5(a) shows a cross-sectional view taken along the dotted line V-V in FIG. 5(b).

[0166] In the battery 2000, the second insulating layer 234 may contain a second glass component. The second insulating layer 234 and the second current collector layer 214 may contain a second glass component. Further, the battery 2000 is different from the battery 1000 according to the first embodiment in that the second current collector layer 214 includes a second metal foil portion 214a and a second metal sintered body portion 214b.

[0167] Similar to the first metal foil portion 110a, the second metal foil portion 214a can be a foil-shaped body, a plate-shaped body, or a mesh-shaped body of metal. The second metal foil portion 214a may not contain a second glass component. Similar to the first metal sintered body portion 110b, the second metal sintered body portion 214b is a sintered body of conductive metal powder and contains a second glass component.

[0168] As the second glass component, various known glass frit powders can be used, similar to the first glass component. The second glass component may have a composition different from that of the first glass component. The second glass component may have a softening point different from that of the first glass component. The glass softening point of the second glass component may be a temperature at which the second current collector layer 214 is not oxidized.

[0169] The second insulating layer 234 contains a second glass component. The second insulating layer 234 covers the second side surface 22 of the second current collector layer 214 and a part of the second main surface 42 continuous from the second side surface 22.

[0170] The second insulating layer 234 is formed, for example, when the second metal sintered body portion 214b is formed, by heat-treating a material containing metal powder and a second glass component at a temperature equal to or higher than the softening point of the second glass component, so that the second glass component that has oozed out to the outside of the second current collector layer 214 solidifies to cover the second side surface 22 (the surface of the second metal sintered body portion 214b) of the second current collector layer 214. That is, the second insulating layer 234 is formed by the second glass component that has oozed out to the exposed surface of the second metal sintered body portion 214b covering and solidifying the second side surface 22 of the second current collector layer 214.

[0171] With the above-described configuration, a highly reliable battery compatible with surface mounting can be obtained.

[0172] The configuration of the battery according to the second embodiment is not limited to the battery 2000 shown in FIG. 5. For example, as described as a modification of the battery according to the first embodiment, also in the battery according to the second embodiment, the second current collector layer 214 may be a multilayer film in which a second metal foil portion 214a and a second metal sintered body portion 214b are laminated. Further, the configuration of each first electrode layer described in the first embodiment and the configuration of the second electrode layer described in the second embodiment may be combined with each other.

[0173] [Method for manufacturing a battery] The method for manufacturing a battery according to the present embodiment may include forming a first insulating layer by heat-treating a first current collector layer forming composition containing a first glass component at a temperature equal to or higher than the glass softening point of the first glass component.

[0174] By the above heat treatment, the first insulating layer and the first current collector layer may be formed. By the above heat treatment, the first insulating layer and the first metal sintered body portion may be formed.

[0175] The first current collector layer forming composition may contain metal powder and powder of the first glass component, and the first insulating layer may be formed by causing at least a part of the first glass component to ooze out to the side surface of the first current collector layer by the above heat treatment.

[0176] According to such a configuration, for example, without requiring a difficult printing pattern such as coating only on the side surface of the current collector, a part of the side surface of the current collector layer can be insulated, and the battery according to the present embodiment can be manufactured.

[0177] The temperature of the heat treatment may be equal to or higher than the glass softening point of the first glass component and a temperature at which the metal contained in the first current collector layer forming composition does not oxidize.

[0178] As described above, the heat treatment is performed, for example, in an inert atmosphere such as N2, Ar, or in a reducing atmosphere containing hydrogen. The heat treatment may be carried out by adjusting the oxygen partial pressure. Thereby, without oxidizing the first current collector layer, that is, without oxidizing the first metal foil portion, the softening of the first glass component and the sintering of the metal powder can be selectively performed.

[0179] The above metal powder may be sintered by the above heat treatment. That is, the metal powder particles may be necked and shrunk by the above heat treatment.

[0180] As the metal powder, the metal described as the metal constituting the first current collector layer in the first embodiment is used. The metal powder may contain Cu.

[0181] Among the first insulating layers formed on the surface of the first current collector layer, for example, unnecessary portions such as the main surface or the second side surface of the first current collector layer can be removed by polishing. Further, before the heat treatment, for example, by resist coating the surface of the first current collector layer with an alumina plate coated with a release agent, the exudation of the first glass component and the formation of the first insulating layer to unnecessary portions can be suppressed.

[0182] The manufacturing method of the present disclosure may include preparing a first active material layer, applying the above-mentioned binder for forming the first current collector layer on the first active material layer, and heat-treating the binder for forming the first current collector layer at a temperature equal to or higher than the glass softening point of the first glass component to form a first insulating layer and a first metal sintered body portion. The manufacturing method of the present disclosure may include preparing a laminate in which a solid electrolyte layer and a first active material layer are laminated, applying the above-mentioned binder for forming the first current collector layer on the surface of the laminate on the first active material layer side, and heat-treating the binder for forming the first current collector layer at a temperature equal to or higher than the glass softening point of the first glass component to form a first insulating layer and a first metal sintered body portion.

[0183] The manufacturing method of the present disclosure may include preparing a first active material layer, applying the above-mentioned binder for forming the first current collector layer on the first active material layer and disposing a metal foil, and heat-treating the binder for forming the first current collector layer at a temperature equal to or higher than the glass softening point of the first glass component to form a first insulating layer and a first current collector layer. The manufacturing method of the present disclosure may include preparing a laminate in which a solid electrolyte layer and a first active material layer are laminated, applying the above-mentioned binder for forming the first current collector layer on the surface of the laminate on the first active material layer side and disposing a metal foil, and heat-treating the binder for forming the first current collector layer at a temperature equal to or higher than the glass softening point of the first glass component to form a first insulating layer and a first current collector layer.

[0184] The manufacturing method of the present disclosure may include preparing a first active material layer, disposing a metal foil on the first active material layer, applying the above-mentioned binder for forming the first current collector layer on the metal foil, and heat-treating the binder for forming the first current collector layer at a temperature equal to or higher than the glass softening point of the first glass component to form a first insulating layer and a first current collector layer. The manufacturing method of the present disclosure may include preparing a laminate in which a solid electrolyte layer and a first active material layer are laminated, disposing a metal foil on the surface of the laminate on the first active material layer side, applying the above-mentioned binder for forming the first current collector layer on the metal foil, and heat-treating the binder for forming the first current collector layer at a temperature equal to or higher than the glass softening point of the first glass component to form a first insulating layer and a first current collector layer.

[0185] The manufacturing method of the above battery may further include preparing a second current collector precursor layer and heat-treating the second current collector precursor layer to oxidize at least a part of the side surface of the second current collector precursor layer to form a second insulating layer and a second current collector layer.

[0186] The second current collector precursor layer may be a layer containing a metal. The second insulating layer may be formed by oxidizing the metal contained in the second current collector precursor layer.

[0187] The manufacturing method of the present disclosure may include preparing a laminate in which a first active material layer, a solid electrolyte layer, and a second active material layer are laminated in this order, forming a second current collector precursor layer on the surface of the laminate on the second active material layer side, and heat-treating the second current collector precursor layer to oxidize at least a part of the side surface of the second current collector precursor layer to form a second insulating layer and a second current collector layer.

[0188] The above oxidation is carried out, for example, by heat treatment. The temperature of the heat treatment may be equal to or higher than the temperature at which the second current collector precursor layer oxidizes and lower than the glass softening point of the first glass component. After forming the first insulating layer, the second current collector precursor layer can be heat-treated and oxidized without melting the first glass component. As described above, the heat treatment is carried out, for example, in an inert atmosphere such as N2, Ar, or in a reducing atmosphere containing hydrogen. The heat treatment may be carried out by adjusting the oxygen partial pressure. Thereby, the surface of the second current collector precursor layer can be selectively oxidized without oxidizing the first current collector layer, that is, without oxidizing the first metal foil part.

[0189] The method for manufacturing the above battery may further include forming a second insulating layer by heat-treating a composition for forming a second current collector layer containing a second glass component at a temperature equal to or higher than the glass softening point of the second glass component.

[0190] The second insulating layer and the second current collector layer may be formed by the above heat treatment. The second insulating layer and the second metal sintered body part may be formed by the above heat treatment.

[0191] The composition for forming the second current collector layer may contain metal powder and powder of the second glass component, and the second insulating layer may be formed by causing at least a part of the second glass component to exude to the side surface of the second current collector layer by the above heat treatment.

[0192] The temperature of the heat treatment for forming the second insulating layer may be equal to or higher than the glass softening point of the second glass component and a temperature at which the metal contained in the composition for forming the second current collector layer does not oxidize. Thereby, the second insulating layer can be formed by melting the second glass component without oxidizing the second current collector layer.

[0193] The metal powder contained in the composition for forming the second current collector layer may be sintered by the above heat treatment. That is, the metal powder particles may neck and shrink by the above heat treatment.

[0194] The metal powder contained in the binder for forming the second current collector layer is the metal described as the metal constituting the second current collector layer in the first embodiment. The metal powder may contain Ni.

[0195] Among the second insulating layers formed on the surface of the second current collector layer, for example, unnecessary portions such as the main surface or the first side surface of the second current collector layer can be removed by polishing, for example. Further, before the heat treatment, for example, by applying a release agent to an alumina plate and resist the surface of the second current collector layer, it is possible to suppress the infiltration of the second glass component and the formation of the second insulating layer to unnecessary portions.

[0196] The order of forming the first current collector layer and the first insulating layer and the order of forming the second current collector layer and the second insulating layer are not particularly limited. For example, the second current collector layer and the second insulating layer may be formed after the first current collector layer and the first insulating layer are formed. In this case, the heat treatment for forming the second insulating layer may be performed at a temperature below the glass softening point of the first glass component, and at a temperature and oxygen partial pressure at which the first current collector layer is not oxidized. Alternatively, the first current collector layer and the first insulating layer may be formed after the second current collector layer is formed, and then the second insulating layer may be formed. In this case, the heat treatment for forming the first insulating layer may be performed at a temperature and oxygen partial pressure at which the second current collector layer is not oxidized.

[0197] When the first glass component and the second glass component have different softening points from each other, heat treatment can be performed at an appropriate temperature according to the metals used for the first current collector layer and the second current collector layer respectively, and the first insulating layer and the second insulating layer with appropriately adjusted bondability and insulating properties with respect to the current collector layer or the active material layer can be formed. In some cases, the first glass component and the second glass component may have the same softening point as each other. In this case, the first insulating layer and the second insulating layer can be formed simultaneously by heat treatment.

[0198] When the metal materials constituting the positive electrode and the negative electrode in a battery are different, since the sintering characteristics and oxidation characteristics of each metal material are different, it is difficult to form appropriate insulating layers on the positive electrode and the negative electrode by the same treatment. According to the method for manufacturing a battery of the present disclosure, for example, after forming the first insulating layer on the side surface of the first current collector layer, the second insulating layer can be formed on the side surface of the second current collector layer, so that a highly reliable battery can be easily manufactured.

[0199] Note that the first current collector layer and the second current collector layer may contain the same metal material, and the first insulating layer and the second insulating layer may be formed simultaneously.

[0200] The method for manufacturing a battery according to the present embodiment may further include forming the first side electrode and the second side electrode on the side surface of the battery after forming the first insulating layer and the second insulating layer.

[0201] Regarding the materials of each member in the method for manufacturing a battery according to the present embodiment, the materials described in the first embodiment and the second embodiment can be used.

[0202] Next, an example of the method for manufacturing a battery according to the present embodiment will be described in detail. Hereinafter, the method for manufacturing the battery 1000 according to the first embodiment described above will be described.

[0203] Hereinafter, an example in which the first electrode layer 100 is a positive electrode and the second electrode layer 200 is a negative electrode will be described.

[0204] First, each paste used for printing and forming the positive electrode active material layer and the negative electrode active material layer, the paste for the solid electrolyte layer, and the alumina paste for the resist of the negative electrode current collector layer are prepared.

[0205] As the solid electrolyte used in the composition of the positive electrode active material layer and the negative electrode active material layer, for example, a powder of the Li7Pr3Zr2O system having an average particle diameter of about 1 μm and mainly composed of garnet crystals is prepared. 12 This powder of the solid electrolyte is, for example, from 1×10 -3 S / cm to 2×10 -3Those having high ionic conductivity of S / cm can be used.

[0206] As the positive electrode active material, for example, a powder of Li·Ni·Co·Al composite oxide (LiNi 0.8 Co 0.15 Al 0.05 O2) with an average particle diameter of about 2 μm and a layered structure is used.

[0207] By dispersing a mixture containing the above-mentioned positive electrode active material and the powder of the above-mentioned solid electrolyte in an organic solvent or the like, a paste for the positive electrode active material layer is produced.

[0208] By dispersing a mixture containing the powder of the above-mentioned solid electrolyte in an organic binder component, an organic solvent or the like, a paste for the solid electrolyte layer used for forming the solid electrolyte layer is produced.

[0209] As the negative electrode active material, for example, a powder of TiNb2O7 with an average particle diameter of about 3 μm is used. By dispersing a mixture containing the above-mentioned negative electrode active material and the powder of the above-mentioned solid electrolyte in an organic solvent or the like, a paste for the negative electrode active material layer is produced.

[0210] The positive electrode active material, the negative electrode active material, and the solid electrolyte are not limited to the above-mentioned ones. As the positive electrode active material, the negative electrode active material, and the solid electrolyte, those that can exhibit their respective characteristics even after going through the heat treatment history for forming the first insulating layer and the second insulating layer described later can be used.

[0211] The alumina paste is produced, for example, by dispersing alumina with a particle diameter of about 1.5 μm in an organic binder, an organic solvent or the like. As the alumina, ordinary commercially available alumina can be used. The alumina only needs to have a sintering temperature higher than the heat treatment temperatures for forming the first insulating layer and the second insulating layer in the production of the battery, and the heat treatment temperature for forming the side electrode. Thereby, the resist can be removed without being fused.

[0212] Note that the material used for the resist is not limited to alumina, and a material with a sintering temperature higher than the heat treatment temperatures for forming the first insulating layer and the second insulating layer described later in the fabrication of the battery, and the heat treatment temperature for forming the side electrodes can be used. Thereby, the resist can be removed without being fused.

[0213] Next, as the material used for the positive electrode current collector layer, a Cu foil with a thickness of 12 μm as the first metal foil part (hereinafter referred to as the "positive electrode metal foil part"), and a paste for forming the first metal sintered body part (hereinafter referred to as the "paste for forming the positive electrode metal sintered body part") are prepared. The paste for forming the positive electrode metal sintered body part is produced by dispersing Bi2O3-B2O3-ZnO-SiO2-based glass powder (softening point 450 °C) with an average particle diameter of 1.0 μm and Cu powder (average particle diameter 0.5 μm) with an average particle diameter of 0.5 μm in a binder component and an organic solvent using three rolls. The content of the glass powder with respect to the Cu powder is 1 mass%.

[0214] As the material used for the negative electrode current collector precursor layer, a Ni foil with a thickness of 12 μm is prepared.

[0215] Next, the solid electrolyte layer paste is formed into a film with a thickness of about 100 μm on a PET film (thickness 50 μm) coated with a Si release agent by the doctor blade method, and dried by blowing air at 80 °C to 130 °C, whereby a solid electrolyte layer sheet with a thickness of about 60 μm is obtained. After that, the PET film is peeled off from the solid electrolyte layer sheet.

[0216] On one surface of the solid electrolyte layer sheet, the positive electrode active material layer paste is applied by screen printing to a thickness of about 50 μm, and then dried by blowing air, whereby a positive electrode active material layer with a thickness of about 30 μm is formed. After that, on the surface of the solid electrolyte layer sheet on the side where the positive electrode active material layer is formed, in the region where the positive electrode active material layer does not exist, the solid electrolyte layer paste is applied by screen printing to a thickness of about 50 μm so as to eliminate the step of the positive electrode active material layer. Then, by drying by blowing air, it becomes a thickness of about 30 μm.

[0217] Next, on the surface of the solid electrolyte layer sheet opposite to the surface on which the positive electrode active material layer is formed, a paste for the negative electrode active material layer is applied and dried in the same manner as the positive electrode active material layer, whereby a negative electrode active material layer with a thickness of about 30 μm is formed. Further, on the surface of the solid electrolyte layer sheet on the side where the negative electrode active material layer is formed, in the region where the negative electrode active material layer does not exist, a paste for the solid electrolyte layer is applied in the same manner as on the positive electrode active material layer side so as to eliminate the step of the negative electrode active material layer and form a layer.

[0218] In this way, a laminate composed of a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer is formed.

[0219] Next, a paste for the positive electrode metal sintered body part is applied by screen printing at a predetermined position on the main surface of the laminate on the positive electrode active material layer side and dried by blowing air at about 90 °C, whereby a coating film of about 10 μm is obtained. Then, the above-mentioned Cu foil as the positive electrode metal foil part is pasted at a predetermined position on the positive electrode active material layer side of the laminate through a silicon sheet elastomer with a hardness of 80 and a thickness of 100 μm by heating press at 70 °C, 70 kg / cm, for 30 seconds. In this way, a positive electrode current collector layer is formed on the laminate.

[0220] Next, the above-mentioned Ni foil is pasted on the main surface of the laminate on the side opposite to the positive electrode current collector layer in the same manner by heating press at 70 °C, 70 kg / cm, for 30 seconds. In this way, a negative electrode current collector precursor layer is formed on the laminate.

[0221] Next, alumina paste is applied to the part of the main surface of the negative electrode current collector layer to be resist-coated with a thickness of about 5 μm and dried by blowing air at about 70 °C to perform resist coating.

[0222] Next, at a temperature equal to or higher than the glass softening point of the glass powder contained in the paste for the positive electrode metal sintered body portion and at a temperature at which the oxygen partial pressure in the heat treatment environment is lower than the equilibrium oxygen partial pressure of Ni so that Ni is not oxidized (for example, 500 °C), the laminate is heat-treated for 10 minutes. By the heat treatment, the glass powder is melted from the coating film and exuded to the side surface of the coating film. Then, by cooling, the melted glass component is re-solidified, and a first insulating layer covering the side surface of the positive electrode current collector layer is formed. At this time, the Cu powder in the coating film is sintered, and a positive electrode metal sintered body portion containing a glass component is also formed.

[0223] Next, the laminate is heat-treated at 400 °C, which is a temperature lower than the glass softening point of the glass powder used in the paste for the positive electrode metal sintered body portion, for 20 minutes. The oxygen partial pressure at this time is adjusted by a mixed gas of hydrogen and CO2 gas to an oxygen partial pressure at which Ni is oxidized and Cu is not oxidized (1×10 -18 Pa). By the heat treatment, Ni, which is the negative electrode current collector precursor layer, is oxidized to form a second insulating layer and a second current collector layer. Then, a resist coated with an alumina paste is removed by rubbing with a nylon brush.

[0224] In the above manner, a power generation element is obtained.

[0225] Next, side electrodes are formed on the side surfaces of the power generation element. First, a thermosetting conductor paste containing silver is applied to the first side surface of the power generation element. Then, a first side surface electrode is formed by thermosetting. At this time, the first side surface electrode and the positive electrode current collector layer are electrically separated by the first insulating layer and are electrically connected to the negative electrode current collector layer. Next, a thermosetting conductor paste containing silver is applied to the second side surface of the power generation element. Then, a second side surface electrode is formed by thermosetting. At this time, the second side surface electrode and the negative electrode current collector layer are electrically separated by the second insulating layer and are electrically connected to the positive electrode current collector layer. The thermosetting conductor paste containing silver may be, for example, a paste containing silver particles and a thermosetting resin, or a paste containing silver particles, low melting point metal particles, and a thermosetting resin.

[0226] In the above manner, the battery 1000 is obtained.

[0227] (Other embodiments) As described above, the battery according to the present disclosure has been described based on the embodiments. However, the present disclosure is not limited to these embodiments. Without departing from the gist of the present disclosure, various modifications conceived by those skilled in the art applied to the embodiments, and other forms constructed by combining some components in the embodiments are also included in the scope of the present disclosure.

[0228] Also, various changes, replacements, additions, omissions, etc. can be made within the scope of the claims or their equivalents in the above embodiments.

[0229] (Supplementary note) From the description of the above embodiments, the following technologies are disclosed.

[0230] (Technology 1) A power generation element including a first electrode layer, a second electrode layer, and a solid electrolyte layer disposed between the first electrode layer and the second electrode layer, The first electrode layer includes a first active material layer, a first current collector layer disposed on the main surface of the first active material layer, and a first insulating layer covering at least a part of the first side surface of the first current collector layer, The second electrode layer includes a second active material layer, a second current collector layer disposed on the main surface of the second active material layer, and a second insulating layer covering at least a part of the second side surface of the second current collector layer, The first insulating layer and the first current collector layer contain a first glass component, Battery.

[0231] According to this configuration, the side surface of the first current collector layer is covered with a dense first insulating layer containing a glass component, which is an inorganic material excellent in barrier properties such as gas and moisture, and high-temperature stability. According to the battery according to Technology 1, a battery excellent in environmental resistance such as gas resistance, moisture resistance, and temperature resistance can be realized. Further, since the side surface of the first current collector layer can be protected by the first insulating layer having excellent mechanical strength, according to the battery according to Technology 1, a battery excellent in impact resistance can be realized. Furthermore, when a side electrode is connected as a lead-out terminal electrode to the side surface of the power generation element, the presence of the first insulating layer and the second insulating layer makes it difficult to contact the current collector layers constituting the respective counter electrodes, and short circuits are suppressed. As described above, the battery according to Technology 1 has high reliability.

[0232] (Technology 2) The battery according to Technology 1, wherein the first side surface of the first current collector layer and the second side surface of the second current collector layer face each other.

[0233] According to the above configuration, a battery having high reliability, excellent in environmental resistance and impact resistance, and with short circuits suppressed can be realized.

[0234] (Technology 3) The battery according to Technology 1 or 2, wherein the second insulating layer contains at least one selected from the group consisting of a metal oxide contained in the second current collector layer and a second glass component. According to such a configuration, a battery having high reliability, excellent in environmental resistance and impact resistance, and with short circuits suppressed can be realized.

[0235] (Technology 4) The battery according to Technology 3, wherein the second insulating layer and the second current collector layer contain a second glass component. According to such a configuration, a battery having high reliability, excellent in environmental resistance and impact resistance, and with short circuits suppressed can be realized.

[0236] (Technology 5) The battery according to Technique 3 or 4, wherein the first glass component and the second glass component have different compositions. According to such a configuration, first insulating layers and second insulating layers, each having appropriate adhesion to the current collector layer or the active material layer and appropriate insulation properties, can be formed on each of the first electrode layer and the second electrode layer.

[0237] (Technique 6) The battery according to any one of Techniques 3 to 5, wherein the first glass component and the second glass component have different glass softening points. According to such a configuration, differences in behaviors such as thermal shrinkage of the first electrode layer and the second electrode layer during heat treatment in the battery manufacturing process can be adjusted by the glass components so as to be suitable for each of the first electrode layer and the second electrode layer. Therefore, appropriate first insulating layers and second insulating layers can be formed.

[0238] (Technique 7) The battery according to any one of Techniques 1 to 6, wherein the first current collector layer contains a metal different from that of the second current collector layer. According to such a configuration, the oxidizability of the metals constituting the first current collector layer and the second current collector layer can be separately controlled, so that the oxide can be appropriately formed only on the second current collector layer. Therefore, in the battery manufacturing process, the first insulating layer and the second insulating layer can be formed under conditions suitable for each of them by heat treatment, and a highly reliable battery can be obtained.

[0239] (Technique 8) The battery according to any one of Techniques 1 to 7, wherein the equilibrium oxygen partial pressure of the first current collector layer is higher than that of the second current collector layer. According to such a configuration, in the battery manufacturing process, by controlling the oxygen partial pressure, the second current collector layer can be oxidized without oxidizing the first current collector layer, and the second insulating layer can be formed.

[0240] (Technique 9) The glass softening point of the first glass component is a temperature at which the first current collector layer is not oxidized, the battery according to any one of Technologies 1 to 9. According to such a configuration, in the manufacturing process of the battery, by heat treatment, the first glass component can be melted without oxidizing the first current collector layer, and the first insulating layer can be formed on the side surface of the first current collector layer. For example, by including the powder of the first glass component in the powder of the metal constituting the first current collector layer and performing heat treatment, the powder of the metal is sintered and shrunk, and the first glass component melts. The melted first glass component exudes to the surface of the first current collector layer and becomes the first insulating layer.

[0241] (Technology 10) The glass softening point of the first glass component is higher than the temperature at which the second current collector layer is oxidized, the battery according to any one of Technologies 1 to 9. According to such a configuration, in the manufacturing process of the battery, after forming the first insulating layer, the second current collector layer can be heat-treated without melting the first glass component.

[0242] (Technology 11) The oxide formation temperature of the second insulating layer is lower than the glass softening point of the first glass component, the battery according to Technology 3. According to such a configuration, in the manufacturing process of the battery, after forming the first insulating layer, the side surface of the second current collector layer is oxidized without remelting the first glass component, thereby forming the second insulating layer. Since the second insulating layer formed in this way is firmly fixed to the second current collector layer, according to the battery according to Technology 11, a second insulating layer excellent in bonding reliability can be obtained.

[0243] (Technology 12) The first current collector layer includes a first metal sintered body portion containing the first glass component, The first insulating layer covers at least a part of the side surface of the first metal sintered body portion, The battery according to any one of Technologies 1 to 11.

[0244] According to the battery according to Technology 12, a battery having high reliability can be easily realized.

[0245] (Technology 13) Further comprising at least one selected from the group consisting of a first side electrode and a second side electrode, The first side electrode is electrically connected to the second electrode layer and is in contact with the first electrode layer via the first insulating layer, The second side electrode is electrically connected to the first electrode layer and is in contact with the second electrode layer via the second insulating layer. The battery according to any one of Technologies 1 to 12.

[0246] According to such a configuration, the first side electrode which is the terminal electrode of the second electrode layer and the second side electrode which is the terminal electrode of the first electrode layer are integrated respectively. Therefore, according to the battery according to Technology 12, a small and highly reliable battery can be realized. Further, the first side electrode and the second side electrode enable surface mounting. Also, a plurality of batteries can be multi-layered and connected by the first side electrode and the second side electrode. Therefore, according to the battery according to Technology 13, a large-capacity battery with surface mounting compatibility and excellent reliability can be configured.

[0247] (Technology 14) At least a part of the first side electrode is embedded in the first insulating layer. The battery according to Technology 13. According to such a configuration, the bonding property between the first side electrode and the first insulating layer becomes strong, so that the peeling of the first side electrode due to the expansion and contraction of the power generation element caused by the thermal cycle and the charge and discharge operation can be suppressed. Therefore, the battery according to Technology 14 has high reliability.

[0248] (Technology 15) At least a part of the second side electrode is embedded in the second insulating layer. The battery according to Technology 13 or 14. According to such a configuration, the bonding property between the second side electrode and the second insulating layer becomes strong, so that the peeling of the second side electrode due to the expansion and contraction of the power generation element caused by the thermal cycle and the charge and discharge operation can be suppressed. Therefore, the battery according to Technology 15 has high reliability. Also, high reliability can be obtained against the impact during surface mounting and the deflection of the mounting substrate.

[0249] (Technology 16) The battery according to any one of Technologies 13 to 15, wherein at least one selected from the group consisting of the first side electrode and the second side electrode includes a metal sintered body. According to such a configuration, the first side electrode and the second current collector layer, and the second side electrode and the first current collector layer can achieve low-resistance connection by the metal sintered structure. Therefore, the battery according to Technology 16 can realize a high-performance battery with small resistance loss.

[0250] (Technology 17) The battery according to any one of Technologies 13 to 16, wherein at least one selected from the group consisting of the first side electrode and the second side electrode includes a conductive resin. According to such a configuration, the charging and discharging operation of the power generation element and the expansion and contraction due to the thermal cycle can be absorbed by the softness of the conductive resin. Therefore, peeling of the first side electrode and the second side electrode due to repeated charging and discharging and thermal cycle is suppressed, and a battery with excellent durability can be obtained.

[0251] (Technology 18) The battery according to any one of Technologies 13 to 17, wherein at least one selected from the group consisting of the first side electrode and the second side electrode has a multilayer structure. According to such a configuration, the connection resistance between the first current collector layer and the second side electrode, the connection resistance between the second current collector layer and the first side electrode, and the resistance of the side electrode itself can be reduced. Also, the first side electrode and the second side electrode can be adjusted so as not to be easily peeled off. From the above, the battery according to Technology 18 can obtain a high-performance and highly reliable battery.

[0252] (Technology 19) The battery according to any one of Technologies 13 to 18, wherein at least one selected from the group consisting of the first side electrode and the second side electrode includes a metal sintered body and a conductive resin, and at least a part of the surface of the metal sintered body is coated with the conductive resin. According to such a configuration, intrusion of gas and moisture that deteriorate battery characteristics can be suppressed by the conductive resin having excellent sealing properties, so that a more high-performance and highly reliable battery can be obtained.

[0253] (Technology 20) The battery according to any one of claims 1 to 19, further comprising a third insulating layer covering at least a part of the surface of the power generation element. According to such a configuration, the power generation element can be protected from characteristic degradation, breakage, and short circuit due to foreign matter attachment or external stress.

[0254] (Technology 21) The battery according to Technology 20, wherein the third insulating layer contains a resin. According to such a configuration, the expansion and contraction due to the charge and discharge operation and the thermal cycle of the power generation element can be absorbed by the elasticity and softness of the resin. Therefore, peeling and cracking of the third insulating layer can be suppressed. From the above, a highly reliable battery can be obtained for the battery according to Technology 21.

[0255] (Technology 22) The battery according to Technology 21, wherein the resin is a thermosetting resin. According to such a configuration, in the manufacturing process of the battery, since the third insulating layer is formed by thermosetting, on the side surface of the power generation element, an organic binder or plasticizer component that is generally often included as a material constituting each layer of the third insulating layer or the power generation element becomes soft due to heating, so that the bonding interface between the third insulating layer and the power generation element is in close contact, and the fixing property between the third insulating layer and the side surface of the power generation element is improved. From the above, a highly reliable battery can be obtained for the battery according to Technology 22.

[0256] (Technology 23) The battery according to any one of Technologies 20 to 22, wherein the third insulating layer has a multilayer structure. According to such a configuration, for example, a structure in which different insulating materials are multilayered can improve the absorbability of the expansion and contraction stress of the power generation element, the bonding property with the side surface of the power generation element, the absorption performance of external stress, and the sealing performance against the intrusion of gas or moisture. From the above, a highly reliable battery can be obtained for the battery according to Technology 23.

[0257] (Technology 24) A method for manufacturing the battery according to any one of Technologies 1 to 23, Forming the first insulating layer by heat-treating a first current collector layer forming composition containing the first glass component at a temperature equal to or higher than the glass softening point of the first glass component, A method for manufacturing a battery.

[0258] According to the above configuration, the first insulating layer can be formed on the side surface of the first current collector layer by heat treatment. Thereby, a first side electrode that is electrically connected to the second current collector layer and not electrically connected to the first current collector layer can be formed on the side surface of the first current collector layer via the first insulating layer.

[0259] (Technology 25) The first current collector layer forming composition contains metal powder and powder of the first glass component, The first insulating layer is formed by exuding at least a part of the first glass component to the side surface of the first current collector layer by the heat treatment. The method for manufacturing a battery according to Technology 24.

[0260] According to the above configuration, the first glass component can be included at an arbitrary location of the first current collector layer (for example, a metal powder structure), for example, at a location where the first insulating layer is desired to be formed on its surface, and then heat-treated. By the heat treatment, the metal powder is sintered and the powder of the first glass component is melted. Due to such an action, the melted and softened first glass component is extruded and exuded from the sintered structure of the metal powder to the surface including the side surface of the first current collector layer, and the first insulating layer can be formed at an arbitrary location.

[0261] (Technology 26) The metal powder is sintered by the heat treatment, and the method for manufacturing a battery according to Technology 25. According to such a configuration, while the metal sintered structure as the first current collector layer is densified, the first glass component is exuded. Thereby, a uniform first insulating layer can be formed on the side surface of the first current collector layer that is densified and has high conductivity. Therefore, the manufacturing method according to Technology 26 can obtain a high-performance and highly reliable battery with low resistance loss.

[0262] (Technology 27) Prepare a second current collector precursor layer, and By heat-treating the second current collector precursor layer, at least a part of the side surface of the second current collector precursor layer is oxidized to form the second current collector layer and the second insulating layer, and The method for manufacturing a battery according to any one of Technologies 24 to 26, further comprising: According to such a configuration, for example, by heat treatment, a second insulating layer can be formed on the side surface of the second current collector layer. Thereby, a second side electrode that is electrically connected to the first current collector layer and not electrically connected to the second current collector layer can be formed on the side surface of the second current collector layer via the second insulating layer.

[0263] (Technology 28) The method for manufacturing a battery according to any one of Technologies 24 to 27, further comprising forming the second insulating layer by heat-treating a second current collector layer-forming composition containing a second glass component at a temperature equal to or higher than the softening point of the second glass component. According to such a configuration, by heat treatment, a second insulating layer can be formed on the side surface of the second current collector layer. Thereby, a second side electrode that is electrically connected to the first current collector layer and not electrically connected to the second current collector layer can be formed on the side surface of the second current collector layer via the second insulating layer.

[0264] (Technology 29) The second current collector layer-forming composition contains a metal powder and a powder of the second glass component, The method for manufacturing a battery according to Technology 28, wherein the second insulating layer is formed by causing at least a part of the second glass component to exude to the side surface of the second current collector layer by the heat treatment.

[0265] According to the above configuration, the second glass component can be included at an arbitrary location of the second current collector layer (for example, a metal powder structure), for example, at a location where it is desired to form the second insulating layer on its surface, and then heat-treated. By heat treatment, the metal powder is sintered and the powder of the second glass component is melted. Due to such an action, the melted and softened second glass component is extruded and exuded from the sintered structure of the metal powder to the surface including the side surface of the second current collector layer, and the second insulating layer can be formed at an arbitrary location.

Industrial Applicability

[0266] The battery according to the present disclosure can be used as a secondary battery such as an all-solid-state battery used in various electronic devices or automobiles, for example.

Explanation of Signs

[0267] 1000, 1001, 1002, 1003, 2000 Batteries 100 First Electrode Layer 110, 111, 112, 113 First Current Collector Layer 110a, 111a, 112a, 112c, 113a First Metal Foil Portion 110b, 111b, 112b, 113b First Metal Sintered Body Portion 120 First Active Material Layer 130, 131, 132, 133 First Insulating Layer 200 Second Electrode Layer 210, 211, 214 Second Current Collector Layer 214a Second Metal Foil Portion 214b Second Metal Sintered Body Portion 220 Second Active Material Layer 230, 231, 234 Second Insulating Layer 300 Solid Electrolyte Layer 400 Power Generation Element 500 First Side Electrode 600 Second Side Electrode

Claims

1. A power generation element including a first electrode layer, a second electrode layer, and a solid electrolyte layer disposed between the first electrode layer and the second electrode layer, The first electrode layer includes a first active material layer, a first current collector layer disposed on a main surface of the first active material layer, and a first insulating layer covering at least a part of a first side surface of the first current collector layer, The second electrode layer includes a second active material layer, a second current collector layer disposed on a main surface of the second active material layer, and a second insulating layer covering at least a part of a second side surface of the second current collector layer, The first insulating layer and the first current collector layer contain a first glass component, A battery.

2. The first side surface of the first current collector layer and the second side surface of the second current collector layer face each other, The battery according to claim 1.

3. The second insulating layer contains at least one selected from the group consisting of an oxide of a metal contained in the second current collector layer and a second glass component, The battery according to claim 1.

4. The second insulating layer and the second current collector layer contain the second glass component, The battery according to claim 3.

5. The first glass component and the second glass component have different compositions from each other, The battery according to claim 3.

6. The first glass component and the second glass component have different glass softening points from each other, The battery according to claim 3.

7. The first current collector layer contains a metal different from that of the second current collector layer, The battery according to claim 1.

8. The equilibrium oxygen partial pressure of the first current collector layer is higher than that of the second current collector layer, The battery according to claim 1.

9. The glass softening point of the first glass component is a temperature at which the first current collector layer is not oxidized, The battery according to claim 1.

10. The glass softening point of the first glass component is higher than the temperature at which the second current collector layer is oxidized, The battery according to claim 1.

11. The formation temperature of the oxide of the second insulating layer is lower than the glass softening point of the first glass component, The battery according to claim 3.

12. The first current collector layer includes a first metal sintered body portion containing the first glass component, The first insulating layer covers at least a part of a side surface of the first metal sintered body portion, The battery according to claim 1.

13. Further comprising at least one selected from the group consisting of a first side surface electrode and a second side surface electrode, The first side electrode is electrically connected to the second electrode layer and is in contact with the first electrode layer via the first insulating layer. The second side electrode is electrically connected to the first electrode layer and is in contact with the second electrode layer via the second insulating layer. The battery according to claim 1.

14. At least a part of the first side electrode is embedded in the first insulating layer. The battery according to claim 13.

15. At least a part of the second side electrode is embedded in the second insulating layer. The battery according to claim 13.

16. At least one selected from the group consisting of the first side electrode and the second side electrode includes a metal sintered body. The battery according to claim 13.

17. At least one selected from the group consisting of the first side electrode and the second side electrode includes a conductive resin. The battery according to claim 13.

18. At least one selected from the group consisting of the first side electrode and the second side electrode has a multilayer structure. The battery according to claim 13.

19. At least one selected from the group consisting of the first side electrode and the second side electrode includes a metal sintered body and a conductive resin, and at least a part of the surface of the metal sintered body is covered by the conductive resin. The battery according to claim 13.

20. The battery further includes a third insulating layer that covers at least a part of the surface of the power generation element. The battery according to claim 1.

21. The third insulating layer includes a resin. The battery according to claim 20.

22. The resin is a thermosetting resin. The battery according to claim 21.

23. The third insulating layer has a multilayer structure. The battery according to claim 20.

24. A method for manufacturing the battery according to any one of claims 1 to 23, including forming the first insulating layer by heat-treating a first current collector layer forming composition containing the first glass component at a temperature equal to or higher than the glass softening point of the first glass component. A method for manufacturing a battery.

25. The first current collector layer forming composition contains a metal powder and a powder of the first glass component, and the first insulating layer is formed by exuding at least a part of the first glass component to the side surface of the first current collector layer by the heat treatment. The method for manufacturing a battery according to claim 24.

26. The metal powder is sintered by the heat treatment. The method for manufacturing a battery according to claim 25.

27. The method for manufacturing a battery according to claim 26. ​

27. preparing a second current collector precursor layer, and further comprising forming the second current collector layer and the second insulating layer by heat-treating the second current collector precursor layer to oxidize at least a part of a side surface of the second current collector precursor layer, The method for manufacturing a battery according to claim 24.

28. further comprising forming the second insulating layer by heat-treating a composition for forming a second current collector layer containing a second glass component at a temperature equal to or higher than the softening point of the second glass component, The method for manufacturing a battery according to claim 24.

29. The composition for forming the second current collector layer contains a metal powder and a powder of the second glass component, and the second insulating layer is formed by causing at least a part of the second glass component to exude to the side surface of the second current collector layer by the heat treatment, The method for manufacturing a battery according to claim 28.

Images