Battery and manufacturing method thereof

Abstract

This battery is provided with: an electric power generation element which comprises at least one cell that contains a positive electrode, a negative electrode and a solid electrolyte layer; and an insulating member which is in contact with the lateral surface of the electric power generation element so as to cover the lateral surface. The insulating member has a wrap-around part which is continuously in contact with the lateral surface and the main surface of the electric power generation element so as to cover the lateral surface and the main surface.

Description

[Technical Field]

[0001] The present disclosure relates to batteries and methods for manufacturing the same. [Background technology]

[0002] Patent Document 1 discloses a lithium-ion battery in which insulating spacers are placed at the corners of a rectangular power generating element in a laminate film. Patent Document 2 discloses a battery in which a pressurized substance containing a fluid and a resin material such as polyethylene are placed between an exterior material and the power generating element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-39271 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-221608 Summary of the Invention [Problem to be solved by the invention]

[0004] Highly reliable batteries are needed. [Means for solving the problem]

[0005] A battery according to one embodiment of the present disclosure includes a power generating element having at least one battery cell including a positive electrode, a negative electrode, and a solid electrolyte layer, and an insulating member that contacts and covers a side surface of the power generating element, and the insulating member has a wraparound portion that contacts and covers each of the side surface and the main surface continuously from the side surface to the main surface of the power generating element. [Effects of the Invention]

[0006] According to the present disclosure, a highly reliable battery can be realized. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 1 of Embodiment 1. FIG. [Figure 3] FIG. 3 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 2 of Embodiment 1. In FIG. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing a part of an insulating member included in a battery according to a second modification of the first embodiment. [Figure 5] FIG. 5 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 3 of Embodiment 1. In FIG. [Figure 6] FIG. 6 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 4 of Embodiment 1. In FIG. [Figure 7] FIG. 7 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to the second embodiment. [Figure 8] FIG. 8 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to the third embodiment. [Figure 9] FIG. 9 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a first modification of the third embodiment. [Figure 10] FIG. 10 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to Modification 2 of Embodiment 3. In FIG. [Figure 11] FIG. 11 is a cross-sectional view illustrating a method for manufacturing a battery according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] (Summary of the Disclosure) A battery according to one aspect of the present disclosure comprises a power generating element having at least one battery cell including a positive electrode, a negative electrode, and a solid electrolyte layer, and an insulating member that contacts and covers a side surface of the power generating element, the insulating member having a wraparound portion that extends from the side surface to a main surface of the power generating element and contacts and covers each of the side surface and the main surface.

[0009] This configuration can prevent short circuits on the side surfaces of the power generating element and prevent contact with foreign objects. It also has the effect of fixing the outer periphery of the power generating element, which is prone to becoming the starting point for peeling of layers when external stress such as bending is applied. This allows for a highly reliable battery. Furthermore, it is possible to thin the battery while improving reliability against vibration and cold and heat, which can result in a battery with high energy density and large capacity, for example.

[0010] Furthermore, for example, the outer surface of the wraparound portion may be rounded.

[0011] This can prevent damage such as chipping at the corners or ridges of the power-generating element due to handling or impact. Furthermore, when the battery is sealed with a laminate film, the battery can be set in the laminate film while preventing the battery from getting caught on the inner wall of the laminate film and being damaged. Furthermore, even when a shock is applied, the occurrence of defects such as pinholes originating from the corners or ridges of the power-generating element can be prevented, resulting in high sealing reliability.

[0012] Furthermore, for example, the insulating member may have a side wall portion that contacts and covers the center of the side surface, and the wraparound portion may have a thickness greater than the thickness of the side wall portion. In other words, the wraparound portion is raised, protrudes, or bulges out more than other parts of the insulating member.

[0013] This allows the positive electrode, negative electrode, and solid electrolyte layer to be more firmly fixed together. For example, the current collector of the positive electrode or negative electrode can be fixed to the active material layer at the outer periphery of the power generating element. Furthermore, the insulating member also functions as a skeletal structure, improving the strength of the thin-layered battery. Furthermore, the provision of the wraparound portion reduces the risk of rubbing and damage to the main surface of the power generating element when the battery is placed. As a result, a more reliable battery can be obtained.

[0014] Furthermore, for example, the insulating member may have a side wall portion that contacts and covers the center of the side surface, and the thickness of the side wall portion may be greater than the thickness of the wraparound portion.

[0015] This makes it possible to more firmly protect the central portion of the side surface and to prevent the solid electrolyte layer from peeling off, etc. This results in a more reliable battery.

[0016] Furthermore, for example, the wraparound portion may have a shape that is curved convexly toward the center of the main surface when viewed in plan.

[0017] This suppresses the problem of opening at the end face of the central region due to external stress that causes bending, which is particularly likely to occur in large-sized batteries, and therefore makes it possible to obtain a highly reliable large-sized battery.

[0018] Furthermore, for example, the wraparound portion may be provided at least at one of the four corners of the main surface.

[0019] This can prevent damage such as chipping at the corners of the power generating element that can occur during handling or impact. Furthermore, when the battery is sealed with a laminate film, the battery can be set in the laminate film while preventing the battery from getting caught on the inner wall of the laminate film and causing damage. Furthermore, even when impact occurs, defects such as pinholes originating from the corners of the power generating element can be prevented, resulting in high sealing reliability.

[0020] Furthermore, for example, the side surface may have a step.

[0021] Even with this configuration, the bonding strength between the insulating member and the side surface of the power generating element is improved, and the resistance to bending is also improved, so a more reliable battery can be obtained.

[0022] Furthermore, for example, at least one of the positive electrode and the negative electrode may have a current collector and an active material layer located between the current collector and the solid electrolyte layer, and the main surface may be a surface of the current collector opposite to a surface on which the solid electrolyte layer is provided.

[0023] In this way, the current collector can be more firmly bonded to the active material layer and the solid electrolyte layer, resulting in a more reliable battery. Furthermore, the edges of the active metal surface exposed by cutting the current collector can be covered with an insulating material. An active metal surface is a surface that is free of adsorbed substances that can react with metals, such as oxygen, nitrogen, moisture, and organic components. This prevents the current collector from reacting with atmospheric components or surrounding substances, resulting in a more reliable battery.

[0024] Furthermore, for example, the insulating member may be softer than the solid electrolyte layer and the active material layer.

[0025] This allows the stress generated at the interface between the insulating member and the side surface of the power generating element during thermal stress or impact to be absorbed, ensuring the bonding strength of the insulating member and protecting the power generating element from impact, resulting in a highly reliable battery.

[0026] Furthermore, for example, the insulating member may be filled into an end portion of at least one of the solid electrolyte layer and the active material layer that contacts the side surface.

[0027] This improves the bonding strength between the insulating member and the side surface of the power generating element, resulting in a more reliable battery.

[0028] Furthermore, for example, the insulating member may include a resin.

[0029] This makes it possible to suppress the occurrence of voids in the insulating member and form a dense and strongly adhered insulating member, thereby obtaining a more reliable battery.

[0030] Furthermore, for example, the insulating member may have a laminated structure of a plurality of insulating films, and the plurality of insulating films may contain different resin materials.

[0031] This makes it possible to obtain an insulating member with properties that cannot be obtained with a single layer film, for example, the reliability and airtightness of the insulating member can be improved compared to a single layer film.

[0032] Furthermore, for example, the plurality of insulating films may have different hardnesses.

[0033] This allows, for example, the insulating film on the bonding surface side with the side of the power generating element to be soft and the insulating film on the surface layer side to be hard, thereby ensuring high adhesion against thermal cycling, etc. By using such multiple resin materials, a more reliable battery can be realized.

[0034] Furthermore, for example, the plurality of insulating films may include a first film in contact with the side surface, and the first film may be softer than the solid electrolyte layer.

[0035] This improves the thermal cycle resistance, particularly in terms of the adhesiveness of the insulating material and the sealing property.

[0036] Furthermore, for example, the first film may be softer than the solid electrolyte layer at or below the lower limit temperature of the operating temperature range.

[0037] This improves the thermal cycling resistance, particularly of the adhesiveness of the insulating material and the sealing property, in the environment in which the battery is used.

[0038] Furthermore, for example, the plurality of insulating films may include a first film in contact with the side surface, and a second film covering the entire surface of the first film opposite to the side surface.

[0039] This allows the formation of an insulating film with better sealing properties, resulting in a highly reliable battery.

[0040] Furthermore, for example, the at least one battery cell may be a plurality of battery cells, and the plurality of battery cells may be stacked.

[0041] This results in a battery with high capacity or high energy density and high reliability.

[0042] Furthermore, for example, the solid electrolyte layer may include a solid electrolyte having lithium ion conductivity.

[0043] This results in a battery with high capacity and energy.

[0044] Furthermore, a method for manufacturing a battery according to an embodiment of the present disclosure may include a step of immersing a side surface of a power generating element having at least one battery cell including a positive electrode, a negative electrode, and a solid electrolyte layer in an insulating material.

[0045] This allows the insulating member to be easily formed on the side surface of the battery.

[0046] As described above, the batteries according to the embodiments of the present disclosure can improve reliability by suppressing short circuits between electrodes, which tend to occur as all-solid-state batteries become thinner, and by improving shock absorption, etc. This makes it possible to thin the battery, and to realize a battery with high energy density, large capacity, and high reliability.

[0047] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0048] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components not described in the independent claims are described as optional components.

[0049] Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, for example, the scales of the figures do not necessarily match. Furthermore, in each figure, substantially the same components are given the same reference numerals, and redundant explanations are omitted or simplified.

[0050] In this specification and drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional Cartesian coordinate system. In each embodiment, the z-axis direction is the thickness direction of the battery. In this specification, the "thickness direction" refers to the direction perpendicular to the surface on which each layer is stacked.

[0051] In addition, in this specification, "plan view" means a view of the battery along the stacking direction of the battery, and "thickness" in this specification means the length of the battery and each layer in the stacking direction.

[0052] In addition, in this specification, the terms "inside" and "outside" refer to the center side of the battery as "inside" and the peripheral side of the battery as "outside" when the battery is viewed along the stacking direction of the battery.

[0053] In this specification, the terms "upper" and "lower" in the battery configuration do not refer to the upper direction (vertically upper) and lower direction (vertically lower) in absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in the stacking configuration. Furthermore, the terms "upper" and "lower" are used not only when two components are arranged with a gap between them and another component exists between them, but also when two components are arranged closely together and the two components are in contact with each other.

[0054] (Embodiment 1) [Battery Overview] First, the battery according to the present embodiment will be described.

[0055] FIG. 1 is a diagram showing a schematic configuration of a battery according to this embodiment. Specifically, FIG. 1(a) is a cross-sectional view of a battery 100 according to this embodiment, and FIG. 1(b) is a plan view of the battery 100 as viewed from the positive side in the z-axis direction. FIG. 1(a) shows a cross section taken along line Ia-Ia in FIG. 1(b). In addition, in FIG. 1(b), the insulating member 40 is shaded with diagonal lines to make the planar shape easier to understand. This also applies to the other plan views described below.

[0056] 1, the battery 100 includes a power generating element 1 and an insulating member 40. The battery 100 is an all-solid-state battery.

[0057] The power generating element 1 is a flat rectangular parallelepiped laminate. As shown in (a) of Figure 1, the power generating element 1 has a main surface 2, a main surface 3 opposite to the main surface 2, and a side surface 4.

[0058] The insulating member 40 contacts and covers the side surface 4 of the power-generating element 1. Specifically, the insulating member 40 continuously contacts and covers each of the main surface 2 and the side surface 4 of the power-generating element 1 from the main surface 2 to the side surface 4. More specifically, the insulating member 40 continuously contacts and covers each of the main surface 2, the side surface 4, and the main surface 3 of the power-generating element 1 from the main surface 2 to the main surface 3. The insulating member 40 covers each of the main surfaces 2 and 3 along their edges. In other words, the insulating member 40 exposes at least the central portion of each of the main surfaces 2 and 3.

[0059] This configuration, according to the present embodiment, can prevent short circuits at the side surface 4 of the power generating element 1 and contact with foreign objects. It also has the effect of fixing the outer periphery, which is a likely starting point for peeling of each layer when external stress such as bending is applied. This allows for a highly reliable battery 100. Furthermore, since it is possible to thin the battery 100 while improving its reliability against vibration and cold and heat, it is possible to obtain a battery 100 with a high energy density and large capacity, for example.

[0060] [Configuration of power generation elements] The specific configuration of the power generating element 1 will be described below.

[0061] The power generating element 1 has a battery cell 1a including an electrode layer 10, a counter electrode layer 20, and a solid electrolyte layer 30 located between and in contact with the electrode layer 10 and the counter electrode layer 20. In this embodiment, the power generating element 1 has only one battery cell 1a. In other words, the power generating element 1 according to this embodiment is the same as the battery cell 1a.

[0062] The electrode layer 10 has a current collector 11 and an active material layer 12. The counter electrode layer 20 has a current collector 21 and an active material layer 22. The solid electrolyte layer 30 is located between the active material layer 12 and the active material layer 22 and is in contact with each other.

[0063] Current collector 11, active material layer 12, solid electrolyte layer 30, active material layer 22, and current collector 21 each have a rectangular shape in a plan view. The planar shapes of current collector 11, active material layer 12, solid electrolyte layer 30, active material layer 22, and current collector 21 are not particularly limited and may be square, or may be a shape other than a rectangle, such as a circle, an ellipse, or a polygon.

[0064] In the present embodiment, current collector 11, active material layer 12, solid electrolyte layer 30, active material layer 22, and current collector 21 are all the same size and have the same outline in a plan view, but this is not limiting. For example, active material layer 12 may be smaller than active material layer 22. Active material layer 12 and active material layer 22 may be smaller than solid electrolyte layer 30. For example, a portion of solid electrolyte layer 30 may be in contact with at least one of current collector 11 and current collector 21.

[0065] The main surface 2 of the power generating element 1 is the surface of the current collector 11 opposite to the surface on which the active material layer 12 is provided. The main surface 2 is part of the outer surface of the power generating element 1. The shape of the main surface 2 in plan view is rectangular.

[0066] The main surface 3 of the power generating element 1 is the surface of the current collector 21 opposite to the surface on which the active material layer 22 is provided. The main surface 2 is part of the outer surface of the power generating element 1. The main surface 3 has a rectangular shape in plan view.

[0067] In (b) of Figure 1, ridgelines 5a, 5b, 5c, and 5d of the power-generating element 1 are indicated by dashed lines. Each of the ridgelines 5a, 5b, 5c, and 5d corresponds to the sides of the rectangular parallelepiped and is a connection between the main surface 2 and the side surface 4. Because the shape of the main surface 2 is rectangular in plan view, the ridgelines 5a and 5b are parallel to each other, and the ridgelines 5c and 5d are parallel to each other. In the following description, when there is no need to distinguish between the ridgelines 5a, 5b, 5c, and 5d, they will be described as ridgeline 5.

[0068] The shape of the power generating element 1 may be a flattened prism such as a hexagonal or octagonal prism, or a flattened circular or elliptical cylinder. Flat means that the thickness is smaller than the width of the base.

[0069] In this embodiment, the electrode layer 10 is a positive electrode, and the counter electrode layer 20 is a negative electrode. Specifically, the current collector 11 is a positive electrode current collector, and the active material layer 12 is a positive electrode active material layer. The current collector 21 is a negative electrode current collector, and the active material layer 22 is a negative electrode active material layer.

[0070] The electrode layer 10 may be a negative electrode and the counter electrode layer 20 may be a positive electrode. Specifically, the current collector 11 may be a negative electrode current collector and the active material layer 12 may be a negative electrode active material layer. The current collector 21 may be a positive electrode current collector and the active material layer 22 may be a positive electrode active material layer.

[0071] In the following description, the positive electrode active material layer and the negative electrode active material layer may be simply referred to as "active material layers." Furthermore, the positive electrode current collector and the negative electrode current collector may be simply referred to as "current collectors."

[0072] The current collectors 11 and 21 may each be formed of an electrically conductive material, and are not particularly limited. The current collectors 11 and 21 may be, for example, a foil, plate, or mesh-like material made of stainless steel, nickel (Ni), aluminum (Al), iron (Fe), titanium (Ti), copper (Cu), palladium (Pd), gold (Au), platinum (Pt), or an alloy of two or more of these metals. The material of the current collectors 11 and 21 may be selected appropriately based on the manufacturing process, the operating temperature, or the operating pressure, and the operating potential and conductivity of the battery applied to the current collectors 11 and 21. The material of the current collectors 11 and 21 may also be selected depending on the required tensile strength or heat resistance. The current collectors 11 and 21 may be a high-strength electrolytic copper foil or a clad material made by laminating different metal foils.

[0073] The thickness of each of the current collectors 11 and 21 is, for example, 10 μm or more and 100 μm or less, but is not limited to this. The surface of the current collector 11 or 21 may be processed to have an uneven, rough surface in order to improve adhesion with the active material layer 12 or 22. The surface of the current collector 11 or 21 may also be coated with an adhesive component such as an organic binder. This strengthens the bonding at the interface between the current collector 11 or 21 and other layers, thereby improving the mechanical and thermal reliability and cycle characteristics of the battery 100.

[0074] The active material layer 12 is located between the current collector 11 and the solid electrolyte layer 30. Specifically, the active material layer 12 is disposed in contact with the main surface of the current collector 11 on the solid electrolyte layer 30 side. In the present embodiment, the active material layer 12 covers the entire main surface of the current collector 11. The active material layer 12 is a positive electrode active material layer, and therefore contains at least a positive electrode active material. In other words, the active material layer 12 is a layer mainly composed of a positive electrode material such as a positive electrode active material.

[0075] The positive electrode active material is a substance in which metal ions such as lithium (Li) ions or magnesium (Mg) ions are inserted into or removed from the crystal structure at a potential higher than that of the negative electrode, and oxidation or reduction occurs accordingly. The type of the positive electrode active material can be appropriately selected according to the type of the battery 100, and known positive electrode active materials can be used.

[0076] As the positive electrode active material, a compound containing lithium and a transition metal element is used. For example, oxides containing lithium and a transition metal element, or phosphate compounds containing lithium and a transition metal element can be mentioned. Examples of the oxide containing lithium and a transition metal element include lithium nickel composite oxides such as LiNi x M 1-x O2 (where M is at least one element among Co, Al, Mn, V, Cr, Mg, Ca, Ti, Zr, Nb, Mo, and W, and x is 0 < x ≦ 1), layered oxides such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganate (LiMn2O4), or lithium manganate having a spinel structure (LiMn2O4, Li2MnO3, LiMnO2) are used. Examples of the phosphate compound containing lithium and a transition metal element include lithium iron phosphate (LiFePO4) having an olivine structure. In addition, sulfides such as sulfur (S) and lithium sulfide (Li2S) can also be used as the positive electrode active material. In this case, a material coated with or added with lithium niobate (LiNbO3) or the like to the positive electrode active material particles can be used as the positive electrode active material. Note that only one kind of these materials may be used as the positive electrode active material, or two or more kinds of these materials may be combined and used.

[0077] As described above, the active material layer 12, which is a positive electrode active material layer, only needs to contain at least a positive electrode active material. The active material layer 12 may also be a mixture layer composed of a mixture of a positive electrode active material and other additive materials. Examples of other additive materials that can be used include solid electrolytes such as inorganic solid electrolytes or sulfide-based solid electrolytes, conductive additives such as acetylene black, and adhesive binders such as polyethylene oxide or polyvinylidene fluoride. By mixing the positive electrode active material with other additive materials such as a solid electrolyte in a predetermined ratio, the active material layer 12 can improve both ionic conductivity and electronic conductivity.

[0078] The thickness of active material layer 12 is, for example, not less than 5 μm and not more than 300 μm, but is not limited to this.

[0079] The active material layer 22 is located between the current collector 21 and the solid electrolyte layer 30. Specifically, the active material layer 22 is disposed in contact with the main surface of the current collector 21 facing the solid electrolyte layer 30. In the present embodiment, the active material layer 22 covers the entire main surface of the current collector 21. The active material layer 22 is a negative electrode active material layer, and therefore contains at least a negative electrode active material. In other words, the active material layer 22 is a layer mainly composed of a negative electrode material such as a negative electrode active material.

[0080] The negative electrode active material is a material in which metal ions such as lithium (Li) ions or magnesium (Mg) ions are inserted or extracted into or from the crystalline structure at a potential lower than that of the positive electrode, and oxidation or reduction occurs accordingly. The type of negative electrode active material can be appropriately selected depending on the type of battery 100, and known negative electrode active materials can be used.

[0081] Examples of the negative electrode active material include carbon materials such as natural graphite, artificial graphite, graphite carbon fiber, and resin-baked carbon, as well as alloy materials that are mixed with a solid electrolyte. Examples of alloy materials include LiAl, LiZn, LiBi, LiCd, LiSb, LiSi, and Li. 4.4 Pb, Li 4.4 Sn, Li 0.17C, lithium alloys such as LiC6, lithium titanate (Li4Ti5O 12 ), zinc oxide (ZnO), or silicon oxide (SiO x ) and other metal oxides can be used. The negative electrode active material may be made of only one of these materials, or a combination of two or more of these materials.

[0082] As described above, the active material layer 22, which is the negative electrode active material layer, only needs to contain at least a negative electrode active material. The active material layer 22 may also be a mixture layer composed of a mixture of a negative electrode active material and other additive materials. Examples of other additive materials that can be used include solid electrolytes such as inorganic solid electrolytes or sulfide solid electrolytes, conductive additives such as acetylene black, and adhesive binders such as polyethylene oxide or polyvinylidene fluoride. By mixing the negative electrode active material with other additive materials such as a solid electrolyte in a predetermined ratio, the active material layer 22 can improve both ionic conductivity and electronic conductivity.

[0083] The thickness of the active material layer 22 is, for example, not less than 5 μm and not more than 300 μm, but is not limited to this.

[0084] The solid electrolyte layer 30 is disposed between and in contact with the active material layer 12 and the active material layer 22. The solid electrolyte layer 30 includes at least a solid electrolyte.

[0085] The solid electrolyte may be any known ion-conductive solid electrolyte for batteries. For example, a solid electrolyte that conducts metal ions such as lithium ions or magnesium ions may be used. The type of solid electrolyte may be selected appropriately depending on the type of ions to be conducted.

[0086] Examples of the solid electrolyte that can be used include inorganic solid electrolytes such as sulfide-based solid electrolytes and oxide-based solid electrolytes. Examples of the sulfide-based solid electrolyte include lithium-containing sulfides such as Li2S-P2S5-based, Li2S-SiS2-based, Li2S-B2S3-based, Li2S-GeS2-based, Li2S-SiS2-LiI-based, Li2S-SiS2-Li3PO4-based, Li2S-Ge2S2-based, Li2S-GeS2-P2S5-based, and Li2S-GeS2-ZnS-based. Examples of the oxide-based solid electrolyte include lithium-containing metal oxides such as Li2O-SiO2 or Li2O-SiO2-P2O5, Li x P y O 1-z N z Lithium-containing metal nitrides such as lithium phosphate (LiPO), lithium-containing transition metal oxides such as lithium titanium oxide, etc., can be used. As the solid electrolyte, only one of these materials may be used, or two or more of these materials may be used in combination. In the present embodiment, the solid electrolyte layer 30 includes, as an example, a solid electrolyte having lithium ion conductivity.

[0087] In addition to the above solid electrolyte material, the solid electrolyte layer 30 may contain a bonding binder such as polyethylene oxide or polyvinylidene fluoride.

[0088] The thickness of solid electrolyte layer 30 is, for example, not less than 5 μm and not more than 150 μm, but is not limited to this.

[0089] The solid electrolyte layer 30 may be formed as an aggregate of solid electrolyte particles, or may be formed as a sintered structure of the solid electrolyte.

[0090] [Insulating material] Next, a specific configuration of the insulating member 40 will be described.

[0091] The insulating member 40 contacts and covers the side surface 4 of the power-generating element 1. It is preferable that the insulating member 40 covers as much of the side surface 4 of the power-generating element 1 as possible. For example, the insulating member 40 covers the entire side surface 4 of the power-generating element 1. In other words, the side surface 4 is not exposed. Specifically, the insulating member 40 covers all of the end surfaces of the current collectors 11 and 21, the end surfaces of the active material layers 12 and 22, and the end surface of the solid electrolyte layer 30. By having the insulating member 40 cover the side surface 4, atmospheric gas can be blocked, resulting in a highly reliable battery 100.

[0092] In particular, the processed portion of the current collector, i.e., the highly active fracture surface exposed immediately after cutting, is prone to react with atmospheric gas components or components of the battery 100. For example, if the current collector 11 or 21 is made of Cu, copper sulfide is easily formed. This reactive portion can act as a starting point, and over time or during battery operation, the reaction can progress to the surrounding area or inside the battery to a level that causes performance degradation.

[0093] To address this problem, the battery 100 according to this embodiment covers the active surfaces of the end faces of the current collectors 11 and 21 with insulating members 40 to block contact with external gases or substances. This makes it possible to suppress corrosion of the current collectors 11 and 21 or reaction with surrounding substances.

[0094] The adsorption state on the surface of current collector 11 or 21 can be analyzed by a surface analysis method such as X-ray photoelectron spectroscopy (XPS) or Electron Spectroscopy for Chemical Analysis (ESCA).

[0095] The insulating member 40 may be provided regardless of its thickness as long as it is capable of preventing short circuits caused by the adhesion of foreign matter. The insulating member 40 can sufficiently prevent short circuits of the power generating element 1 by contacting and covering the entire surface of the side surface 4.

[0096] In this case, if the thickness of the insulating member 40 is 10 μm or more, the electrical insulation can be sufficiently improved. Furthermore, if the thickness of the insulating member 40 is, for example, 100 μm or more, the shock absorption can be improved. Furthermore, if the thickness of the insulating member 40 is, for example, 1 mm or more, the air or moisture blocking performance can be improved. There is no particular upper limit on the thickness of the insulating member 40, but it is set to an appropriate thickness in order to suppress a decrease in the energy density or volume capacity density of the battery 100.

[0097] These thicknesses are merely examples and may be changed as appropriate depending on the type of material contained in the insulating member 40. For example, in the case of epoxy-based resin, a thickness of 50 μm or more can provide a gas and moisture blocking effect. As a simple test of the blocking ability of the insulating member 40, the power generating element 1 using an LPS-based sulfide-based solid electrolyte, which is susceptible to moisture, can be left in the atmosphere and its operation confirmed, thereby estimating the practical blocking ability of the insulating member 40.

[0098] For example, when the side surfaces 4 of a power generating element 1 containing a sulfide-based solid electrolyte and measuring 20 mm long x 20 mm wide x 0.2 mm thick were covered with a 50 μm thick epoxy resin, the battery maintained charge / discharge characteristics without any problems for approximately 5 hours. In contrast, when the side surfaces 4 of a power generating element 1 containing a sulfide-based solid electrolyte and of the same size were left exposed, a short circuit was confirmed 30 minutes after being left in the air. In other words, it was confirmed that the durability of the battery 100 was improved by covering it with the insulating member 40. This method allows us to estimate the actual moisture and gas barrier effect.

[0099] Furthermore, the thickness of the insulating member 40 may be 150 μm or more. In this case, the aforementioned simple test showed a durability of 300 hours or more. By conducting simple tests with various thicknesses, it is possible to determine the thickness that provides a stronger blocking effect. For example, by conducting simple tests in advance depending on the properties of the insulating member 40 or the environment in which durability is desired, the material and thickness of the insulating member 40 can be appropriately determined.

[0100] It should be noted that the thicker the insulating member 40, the more preferable it is for achieving high reliability. However, since this naturally leads to an increase in volume, it is desirable to set the thickness appropriately at a required level in order to achieve both capacity and energy density and reliability.

[0101] The insulating member 40 may be any electrical insulator. Specifically, the insulating member 40 includes an insulating resin. For example, the insulating member 40 may be a liquid or powder thermosetting epoxy resin.

[0102] In the present embodiment, insulating member 40 is softer than solid electrolyte layer 30 and active material layers 12 and 22. In addition, insulating member 40 is softer than current collectors 11 and 21. For example, insulating member 40 can be made of a general epoxy-based material with a hardness and an elastic modulus of 10 GPa or more and 40 GPa or less.

[0103] This makes it possible to absorb impacts on the areas covered with the insulating member 40, maintain the reliability of the bonding interface, and protect the battery 100. Furthermore, even when a thermal cycle is applied, the softness of the insulating member 40 absorbs the stress acting on the interface with the insulating member 40 due to the difference in thermal expansion between the two. This makes it possible to suppress adverse effects such as cracking on the solid structure of the power generating element 1.

[0104] The relative softness of current collectors 11 and 21, active material layers 12 and 22, and solid electrolyte layer 30, relative to insulating member 40, can be determined by applying a rigid indenter to the object to be measured and comparing the magnitude of the marks, similar to Vickers hardness measurement. For example, when an indenter is pressed with the same force against each portion of the cross section of power generating element 1 and insulating member 40, insulating member 40 will be in a state where it is dented more than the others.

[0105] Furthermore, the above-described softness relationship may hold true throughout the operating temperature range of the battery 100. In general, the lower the temperature, the harder the resin contained in the insulating member 40 tends to be. Therefore, it is sufficient that the insulating member 40 is softer than the solid electrolyte layer 30 and the active material layers 12 and 22 at or below the lower limit of the operating temperature range. For example, at low temperatures such as 0 degrees Celsius to minus 25 degrees Celsius, the insulating member 40 is softer than the solid electrolyte layer 30 and the active material layers 12 and 22. This can particularly improve the cold and heat cycle resistance performance of the battery 100.

[0106] The insulating member 40 according to this embodiment covers not only the side surface 4 but also a portion of each of the main surface 2 and the main surface 3. Specifically, as shown in FIG. 1(a), the insulating member 40 has a side wall portion 41 that contacts and covers the center of the side surface 4, and two wraparound portions 42 and 43.

[0107] The side wall portion 41 is provided in an annular shape along the side surface 4 of the power generating element 1. The side wall portion 41 contacts and covers the side surfaces of the solid electrolyte layer 30 and the active material layers 12 and 22 of the power generating element 1.

[0108] The wraparound portion 42 extends continuously from the side surface 4 to the main surface 2 of the power generating element 1, contacting and covering each of the side surface 4 and the main surface 2. Specifically, the wraparound portion 42 contacts and covers all of the ridge lines 5a, 5b, 5c, and 5d. In other words, the wraparound portion 42 is provided in a ring shape along the edge of the main surface 2 of the power generating element 1, as shown in FIG. 1(b).

[0109] Wrapping portion 42 is, for example, a portion that continuously covers part of main surface 2, ridge line 5, and part of side surface 4. Specifically, wrapping portion 42 continuously covers the end face of current collector 11 and part of the end face of active material layer 12. In the present embodiment, the outer surface of wrapping portion 42 is rounded.

[0110] The wraparound portion 43 extends continuously from the side surface 4 to the main surface 3 of the power generating element 1, contacting and covering both the side surface 4 and the main surface 3. The wraparound portion 43 is the same as the wraparound portion 42 except that it covers the edge of the main surface 3 instead of the main surface 2. Therefore, the following description will focus on the wraparound portion 42. The features of the wraparound portion 42 are also applicable to the wraparound portion 43.

[0111] The provision of the wraparound portion 42 has the effect of more firmly bonding the current collector 11 and each layer of the power generating element 1. For example, it is possible to prevent the current collector 11 or each layer of the power generating element 1 from peeling off due to external stress such as cold, heat, or stress. In particular, it is possible to firmly fix even the center of the cell's side surface 4, which is prone to peeling, against bending stress, which is a problem in large-sized cells. This improves the bending resistance of the battery 100.

[0112] The wraparound width of the wraparound portion 42 is equal to the thickness of the power generating element 1. The wraparound width is the distance from the ridge line 5 to the end of the wraparound portion 42 in a plan view. Note that "equal" means, for example, that the difference is within ±10%.

[0113] This achieves a stress balance between the main surface 2 and the side surface 4, thereby achieving the effect of sufficiently improving the integration of the power generating element 1 and the insulating member 40. For example, if the power generating element 1 has long sides of 15 cm, short sides of 10 cm, and a thickness of 200 μm, the insulating member 40 has a thickness of approximately 150 μm, and the wraparound portion 42 has a wraparound width of approximately 200 μm. This configuration not only ensures the integrity of the battery 100, but also allows the wraparound portion 42 to block the intrusion path of air and other gases into the end face of the current collector 11. Specifically, the wraparound portion 42 can extend the intrusion path, thereby more reliably protecting the end face of the current collector 11. Of course, setting the wraparound width too large will result in a decrease in the capacity density of the battery 100, so it is preferable to set it within an appropriate range.

[0114] The side wall portion 41 and the wraparound portion 42 are continuously integrated via the ridge line 5. This allows the respective effects to be obtained simultaneously based on the principle of their action and effect. Furthermore, the rounded outer surface of the wraparound portion 42 can suppress cracking and chipping during handling during assembly. Furthermore, for example, when the battery 100 is placed in a sealing bag made of laminate film or the like, stress that could damage the wall surface of the sealing bag can be reduced. This allows a high airtight state to be maintained, improving the sealing reliability of the battery 100.

[0115] [Effects, etc.] According to the above configuration, the insulating member 40 having at least one of the wraparound portions 42 and 43 can firmly prevent short circuits between electrodes, contact with foreign matter, and corrosion and reaction of the current collector. Furthermore, the wraparound portions 42 and 43 also have the effect of firmly integrating all layers of the power generating element 1, even in a large, thin battery 100. This makes it possible to reduce the thickness of the battery 100, which is prone not only to short circuits but also to structural damage or defects, and results in a battery 100 with high energy density and high reliability.

[0116] As described above, according to this embodiment, a highly reliable battery 100 with a high energy density and large capacity can be realized.

[0117] Note that when comparing the battery 100 according to the present embodiment with the battery configurations described in Patent Documents 1 and 2, the following differences exist. Patent Document 1 discloses a lithium-ion battery in which insulating spacers are disposed at the corners of a rectangular power-generating element within a laminate film. However, this lithium-ion battery is a battery containing an electrolyte solution. Furthermore, the insulating spacers are not fixed to the power-generating element. Therefore, the battery disclosed in Patent Document 1 does not have a structure in which a power-generating element containing a solid electrolyte is fixed and integrated, and its purpose and configuration are different from those of battery 100 according to the present embodiment.

[0118] On the other hand, Patent Document 2 discloses a battery having a fluid-containing pressurized substance and a resin material member such as polyethylene between an exterior material and a power generating element. However, the fluid-containing pressurized substance and the resin material member are not fixed to the power generating element. This poses a problem in that external stresses such as thermal cycling or flexural stress can easily cause delamination between the current collector and separators such as solid electrolyte layers. As such, the battery disclosed in Patent Document 2 differs in purpose and configuration from the battery 100 according to the present embodiment.

[0119] In contrast, according to the present embodiment, the above-mentioned problems do not occur, and it is possible to realize a battery 100 that has a high energy density, a large capacity, and high reliability. Note that Patent Documents 1 and 2 do not disclose or suggest an all-solid-state battery including an insulating member 40 having at least one of the wraparound portions 42 and 43.

[0120] [Variation 1] The following describes Modification 1 of Embodiment 1. In the following description of Modification 1, differences from Embodiment 1 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0121] Fig. 2 is a diagram showing a schematic configuration of a battery 101 according to Modification 1 of Embodiment 1. Specifically, Fig. 2(a) is a cross-sectional view of the battery 101 according to this modification, and Fig. 2(b) is a plan view of the battery 101 as seen from the positive side in the z-axis direction. Fig. 2(a) shows a cross section taken along line IIa-IIa in Fig. 2(b).

[0122] As shown in FIG. 2, battery 101 according to this modification differs from battery 100 according to embodiment 1 in that it includes insulating member 40A instead of insulating member 40. Insulating member 40A includes wrapping portions 42A and 43A instead of wrapping portions 42 and 43. Wrapping portion 43A is the same as wrapping portion 42A except that it covers the edge of main surface 3 instead of main surface 2. Therefore, the following description will focus on wrapping portion 42A. The features of wrapping portion 42A are also applicable to wrapping portion 43A.

[0123] 2(b), in a plan view of the main surface 2, the wraparound portion 42A has a shape that is curved convexly toward the center of the main surface 2. Ends 42Aa, 42Ab, 42Ac, and 42Ad of the wraparound portion 42A are portions that face the ridgelines 5a, 5b, 5c, and 5d, respectively, and are smoothly curved in an elliptical arc or circular arc shape so as to be convex toward the center.

[0124] The curvature width of the end 42Aa is, for example, equivalent to the thickness of the battery 101. The curvature width of the end 42Aa is expressed as the distance between a straight line connecting both ends of the end 42Aa and the position on the end 42Aa that is farthest from the straight line. The position on the end 42Aa that is farthest from the straight line connecting both ends of the end 42Aa is, for example, the intersection of the perpendicular bisector of the ridge line 5a and the end 42Aa, but is not limited to this. The curvature width of each of the ends 42Ab, 42Ac, and 42Ad is also, for example, equivalent to the thickness of the battery 101.

[0125] With this configuration, a large, thin cell is subjected to a pressing force from the edge of the main surface of the current collector 11 to the inner region. Therefore, even when a bending stress is applied, the layers can be fixed together without peeling. Furthermore, the penetration path of moisture and the like that flows between the joint surfaces of the current collector 11 and the insulating member 40A can be blocked. This increases the penetration distance, thereby improving environmental resistance. In this way, this modification makes it possible to realize a thinner battery 101 with higher reliability.

[0126] Furthermore, since the wraparound portion 42A has a convexly curved shape, it is particularly effective in suppressing peeling at the center of each ridge line where stress tends to concentrate when bending stress acts on the battery 101. Even a slight curve from a straight line can be effective, but a curve width of about the thickness of the battery 101, for example, is sufficient to achieve a sufficient effect.

[0127] [Variation 2] Next, a description will be given of Modification 2 of Embodiment 1. In the following description of Modification 2, differences from Embodiment 1 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0128] Fig. 3 is a diagram showing a schematic configuration of a battery 102 according to a second modification of the first embodiment. Specifically, Fig. 3(a) is a cross-sectional view of the battery 102 according to this modification, and Fig. 3(b) is a plan view of the battery 102 as viewed from the positive side in the z-axis direction. Fig. 3(a) shows a cross section taken along line IIIa-IIIa in Fig. 3(b). Fig. 4 is an enlarged cross-sectional view showing a portion of an insulating member 40B included in the battery 102 according to this modification.

[0129] As shown in FIG. 3, battery 102 according to this modification differs from battery 100 according to embodiment 1 in that it includes insulating member 40B instead of insulating member 40. Insulating member 40B includes wraparound portions 42B and 43B instead of wraparound portions 42 and 43. Wraparound portion 43B is the same as wraparound portion 42B except that it covers the edge of main surface 3 instead of main surface 2. Therefore, the following description will focus on wraparound portion 42B. The features of wraparound portion 42B are also applicable to wraparound portion 43B.

[0130] In this modification, the side wall portion 41 and the wraparound portion 42B have different thicknesses. Specifically, as shown in FIG. 4, the thickness t1 of the side wall portion 41 is greater than the thickness t2 of the wraparound portion 42B. The side wall portion 41 has a uniform thickness t1. The thickness t2 of the wraparound portion 42B is expressed, for example, as the distance between the side surface 4 and the portion of the wraparound portion 42B that is farthest from the side surface 4.

[0131] Increasing the thickness t2 of the wraparound portion 42B can particularly improve the resistance to flexure, which is likely to become apparent in large, thin batteries. Specifically, the effect of strongly suppressing flexure can be exerted widely and strongly from the outer periphery of the main surface 2 to the inside by firmly sandwiching the power generating element 1 between the side wall portion 41 and the wraparound portion 42B. This can suppress peeling of the current collector 11.

[0132] The height of the wraparound portion 42B, i.e., the distance between the main surface 2 and the portion of the wraparound portion 42B that is farthest from the main surface 2, is also greater than the thickness t1 of the side wall portion 41. For example, the height of the wraparound portion 42B is equal to the thickness t2 of the wraparound portion 42B.

[0133] 4, the wraparound portion 42B is higher than the main surface 2. Therefore, when the battery 102 is placed on a predetermined installation surface, the wraparound portion 42A mainly supports the power generating element 1 instead of the current collector 11 that forms the bottom surface of the battery 102. This makes it less likely that the bottom surface of the current collector 11, i.e., the main surface 2 of the power generating element 1, will come into direct contact with the installation surface, thereby reducing scratches or damage.

[0134] In this modification, a portion of insulating member 40B fills the end portion of at least one of solid electrolyte layer 30, active material layer 12, and active material layer 22 that contacts side surface 4. Specifically, active material layer 12, solid electrolyte layer 30, and active material layer 22 of battery 102 generally have pores on the order of microns. That is, as shown in FIG. 4 , pores are formed between particles 13 that make up each layer. A portion of insulating member 40B fills the pores between particles 13.

[0135] Typically, the porosity of each layer at the end of side surface 4 is 10% or less. By filling some of the insulating material 40B into these pores, the anchoring effect between insulating material 40B and each layer is improved, thereby further strengthening the integrity of battery 102. As a result, even if microcracks or delamination exist on side surface 4, they are fixed by hardened insulating material 40B, which provides structural stability and prevents defects from expanding.

[0136] Furthermore, the provision of wraparound portions 42B and 43B strengthens the bond between the bonded surfaces, preventing voids from forming at the bonded interface due to external stress such as flexural stress, thereby further improving the reliability of the barrier effect against moisture and gas.

[0137] Such a microstructure in which a portion of the insulating member 40B fills the pores is formed, for example, by applying a liquid epoxy resin to the side surface 4 and thermally curing it in a vacuum dryer, thereby curing the resin in a state in which the resin has entered the open pores under reduced pressure. Note that such a microstructure in which the insulating member 40B has entered can be observed by a general cross-sectional observation method such as a cut cross section, a polished cross section, or ion milling. Note that such a microstructure is not limited to this modification, and may be similar in other modifications as well as in Embodiment 1 and other embodiments.

[0138] Note that, when part of the insulating member 40B fills the active material layer 12 and the solid electrolyte layer 30, the boundary between the insulating member 40B and the power generating element 1, i.e., the side surface 4, may become unclear. In this case, the side surface 4 can be regarded as a surface flush with the end surface of the current collector 11, as represented by the dashed line in Fig. 4. Alternatively, the side surface 4 may be regarded as a plane connecting the end surface of the current collector 11 and the end surface of the current collector 21.

[0139] In this modification, the wraparound portion 42B is provided at least at one of the four corners of the main surface 2. Specifically, as shown in Fig. 3(b), the wraparound portion 42B has corners 44a, 44b, 44c, and 44d that respectively cover the four corners 6a, 6b, 6c, and 6d of the main surface 2. Each of the corners 6a, 6b, 6c, and 6d is a connection portion between two adjacent ridges.

[0140] Corner portions 44a, 44b, 44c, and 44d are each slightly larger than the other portions. For example, the thickness and height of corner portion 44a are both greater than the thickness and height of the central portion of ridge line 5a of wraparound portion 42B (specifically, the portion on line IIIa-IIIa in FIG. 3(b)). In addition, in plan view, the edge of corner portion 44a on the center side of main surface 2 is curved concavely outward. Corner portions 44b, 44c, and 44d also have a similar shape. In other words, the inner contour of wraparound portion 42B in plan view is a rounded rectangular shape.

[0141] The shape of the wraparound portion 42B is not particularly limited. For example, the wraparound portion 42B may have only one of the corners 44a, 44b, 44c, and 44d. Furthermore, the wraparound portion 42B and the wraparound portion 43B may differ in at least one of their shapes and sizes.

[0142] [Variation 3] Next, a description will be given of Modification 3 of Embodiment 1. In the following description of Modification 3, differences from Embodiment 1 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0143] Fig. 5 is a diagram showing a schematic configuration of a battery 103 according to Modification 3 of Embodiment 1. Specifically, Fig. 5(a) is a cross-sectional view of the battery 103 according to this modification, and Fig. 5(b) is a plan view of the battery 103 as viewed from the positive side in the z-axis direction. Fig. 5(a) shows a cross section taken along line Va-Va in Fig. 5(b).

[0144] As shown in FIG. 5, battery 103 according to this modification differs from battery 100 according to embodiment 1 in that it includes insulating member 40C instead of insulating member 40. Insulating member 40C includes side wall portion 41C and wraparound portions 42C and 43C. Wraparound portion 43C is the same as wraparound portion 42C except that it covers the edge of main surface 3 instead of main surface 2. Therefore, the following description will focus on wraparound portion 42C. The features of wraparound portion 42C are also applicable to wraparound portion 43C.

[0145] In this modification, the thickness t1 of the side wall portion 41C is greater than the thickness t2 of the wraparound portion 42C. That is, the insulating member 40C is formed to be thicker toward the center in the thickness direction of the power generating element 1 and thinner toward the ends.

[0146] In the battery 103 according to this modification, short circuits between electrodes, contact with foreign matter, and corrosion and reaction of the current collector can also be effectively prevented. Furthermore, the wraparound portions 42C and 43C have the effect of firmly integrating all layers of the power generating element 1, even in a large, thin battery 103. This results in a highly reliable battery 103 with a high energy density and large capacity.

[0147] [Variation 4] Next, a fourth modification of the first embodiment will be described. In the following description of the fourth modification, differences from the first embodiment will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0148] Fig. 6 is a diagram showing a schematic configuration of a battery 104 according to Modification 4 of Embodiment 1. Specifically, Fig. 6(a) is a cross-sectional view of the battery 104 according to this modification, and Fig. 6(b) is a plan view of the battery 104 as viewed from the positive side in the z-axis direction. Fig. 6(a) shows a cross section taken along line VIa-VIa in Fig. 6(b).

[0149] 6, the battery 104 according to this modification differs from the battery 100 according to the first embodiment in that it includes an insulating member 140 instead of the insulating member 40. The insulating member 140 has a laminated structure of multiple insulating films. Specifically, the insulating member 140 includes a first film 140a and a second film 140b.

[0150] The first film 140a is in contact with the side surface 4 of the power-generating element 1. The first film 140a is in contact with and covers each of the main surface 2, the side surface 4, and the main surface 3 continuously from the main surface 2 via the side surface 4 to the main surface 3. In other words, the first film 140a is included in each of the side wall portion 141 and the wraparound portions 142 and 143 of the insulating member 140.

[0151] The second film 140b covers the entire surface of the first film 140a opposite the side surface 4. The second film 140b is formed to be slightly larger than the first film 140a so as not to expose the first film 140a. Specifically, the second film 140b continuously covers and contacts the main surface 2, the first film 140a, and the main surface 3 from the main surface 2 via the side surface 4 to the main surface 3. In other words, the second film 140b is included in each of the side wall portion 141 and the wraparound portions 142 and 143 of the insulating member 140. In this way, the second film 140b completely covers the first film 140a up to the edge, thereby improving the sealing performance of the insulating member 140.

[0152] The first film 140a and the second film 140b contain different resin materials. For example, the first film 140a and the second film 140b have different hardnesses. Specifically, the first film 140a is softer than the second film 140b. The first film 140a is also softer than the solid electrolyte layer 30 and the active material layers 12 and 22. Specifically, the first film 140a is softer than the solid electrolyte layer 30 and the active material layers 12 and 22 at or below the lower limit of the operating temperature range of the battery 104. This can particularly improve the cold-heat cycle resistance of the battery 104.

[0153] Generally, when a thick insulating resin material is applied and cured, peeling of the applied resin material due to curing stress is likely to occur. In contrast, according to this modification, the insulating member 140 can be easily thickened by stacking thin insulating films. For example, a thin, cured epoxy resin of about 10 μm to 50 μm is coated with additional epoxy resin and cured repeatedly. This fills pores, levels out thickness variations, and forms a dense, strong, thick insulating member 140 that does not peel. Specifically, an insulating member 140 with a thickness of 500 μm or more can be formed.

[0154] In this way, the thickness of the insulating member 140 is increased by the laminated structure compared to a single-layer film. This reduces defects of the single-layer film, such as voids. Furthermore, since it is possible to increase the thickness while suppressing the occurrence of cracks or peeling, a highly reliable battery 104 can be obtained. Furthermore, by forming a multilayer of insulating films with different properties, it is possible to form an insulating member 140 with desired properties, such as heat resistance, impact resistance, or airtightness.

[0155] In this modification, the second film 140b is formed so as to completely cover the underlying first film 140a. The insulating member 140 having such a layered structure improves passivation and further prevents the intrusion of external air. Of course, the insulating member 140 can also be formed with a thickness of 1 mm. The insulating member 140 having such a layered structure can be observed as a layered structure resulting from repeated application and curing processes through general observation of a polished cross section using an optical microscope or a scanning electron microscope (SEM).

[0156] For example, by repeatedly applying and curing insulating materials in the order of high to low curing temperatures or glass transition points, a dense and thick insulating member 140 can be formed without deteriorating the properties of the underlying insulating film due to the heat during curing. The thermal curing conditions are set to a temperature or time within a range that does not adversely affect the characteristics of the battery 104.

[0157] In this modification, the insulating films included in the insulating member 140 may be formed using the same material. This is easier to form than a single-layer structure, and allows for the formation of an insulating member 140 with fewer defects and high performance in protecting the side surface 4.

[0158] The number of laminated insulating films included in the insulating member 140 may be three or more. In this modification, the side wall portion 141 and the wraparound portions 142 and 143 may have different numbers of laminated layers, or may have different hardnesses. For example, if it is desired to improve the impact resistance of the battery 104 and the corrosion resistance and reactivity resistance of the current collectors, it is naturally effective to protect the side surfaces where the ends of the power generating element 1 and the current collectors are exposed. For this reason, the impact resistance, corrosion resistance, and reactivity resistance can be improved by thickening the insulating member 140.

[0159] (Embodiment 2) The following describes embodiment 2. In the following description of embodiment 2, differences from embodiment 1 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0160] Fig. 7 is a cross-sectional view and a plan view showing a schematic configuration of a battery 200 according to embodiment 2. Specifically, Fig. 7(a) is a cross-sectional view of the battery 200 according to this embodiment, and Fig. 7(b) is a plan view of the battery 200 as viewed from the positive side in the z-axis direction. Fig. 7(a) shows a cross section taken along line VIIa-VIIa in Fig. 7(b).

[0161] 7, the battery 200 according to the present embodiment includes a power generating element 201 and an insulating member 240. The power generating element 201 has only one battery cell 201a. The battery cell 201a differs from the battery cell 1a of the battery 100 according to the first embodiment in that the side surface 204 has a step.

[0162] 7, the solid electrolyte layer 30 is disposed so as to be offset from the electrode layer 10 and the counter electrode layer 20. Specifically, the solid electrolyte layer 30 is disposed so as to protrude toward the positive x-axis direction relative to the electrode layer 10 and the counter electrode layer 20. As a result, the side surface 204 of the power generating element 201 has a concave step on the negative x-axis direction and a convex step on the positive x-axis direction.

[0163] In this embodiment, the insulating member 240 covers the step on the side surface 204. Specifically, the side wall portion 241 of the insulating member 240 has a different thickness depending on the step on the side surface 204. For example, a concave step is formed on the negative side in the x-axis direction, so the thickness of the side wall portion 241 is thicker in the portion along the solid electrolyte layer 30 and thinner in the portion along the electrode layer 10 and the counter electrode layer 20. Conversely, a convex step is formed on the positive side in the x-axis direction, so the thickness of the side wall portion 241 is thinner in the portion along the solid electrolyte layer 30 and thicker in the portion along the electrode layer 10 and the counter electrode layer 20.

[0164] The formation of a step on the side surface 204 makes it easier for gases such as the atmosphere and moisture to penetrate through the gap between the side surface 204 and the insulating member 240. In contrast, according to the present embodiment, the insulating member 240 fits into the step on the side surface 204, improving the adhesiveness of the insulating member 240. In other words, the intrusion of gases, moisture, and the like can be more effectively blocked, improving the sealing of the power generating element 201. This suppresses the intrusion of these substances even in an environment where the atmosphere or moisture is present, improving the environmental resistance of the battery 200 and also improving reliability against stresses such as thermal cycles, impact resistance, or repeated charge and discharge. Furthermore, the step has the effect of suppressing peeling of the insulating member 240 against stresses generated when the insulating member 240 hardens, further improving the adhesiveness reliability.

[0165] The layer on which the step is provided may be any of the electrode layer 10, the solid electrolyte layer 30, and the counter electrode layer 20. For example, the solid electrolyte layer 30 may be configured as a stacked structure of two layers, and the two layers may be formed so as to be offset. Alternatively, the step may be formed by offsetting the active material layer 12 or 22, or the current collector 11 or 21.

[0166] The effect of providing the step is to increase the bonding area between the side surface 204 and the insulating member 240, thereby increasing the bonding strength between the power generating element 1 and the insulating member 240. Furthermore, the intrusion path of gas, moisture, and the like along the interface between the side surface 204 and the insulating member 240 is bent and its length is extended, thereby improving the protection performance against gas and moisture.

[0167] For example, a sufficient effect can be obtained by forming a step of approximately the same size as the thickness of each layer. For example, if the thickness of the solid electrolyte layer 30 is 30 μm, a step of approximately 30 μm may be provided. The size of the step corresponds to the amount of protrusion or recession when the side surface 204 is considered to be a flat surface. For example, in the example shown in FIG. 7(a), the amount of protrusion or recession of the solid electrolyte layer 30 is several μm or more and several mm or less, but is not particularly limited. Note that an excessively large step reduces the energy density or capacity of the battery 200, so an appropriate range is preferable.

[0168] Furthermore, the sizes of the layers constituting the battery cell 201a may be different. For example, the size of the solid electrolyte layer 30 in a planar view may be larger than the size of each of the electrode layer 10 and the counter electrode layer 20 in a planar view. As a result, the solid electrolyte layer 30 protrudes from the electrode layer 10 and the counter electrode layer 20, forming a convex step on the side surface 204. Alternatively, the size of the solid electrolyte layer 30 in a planar view may be smaller than the size of each of the electrode layer 10 and the counter electrode layer 20 in a planar view. As a result, the solid electrolyte layer 30 is recessed relative to the electrode layer 10 and the counter electrode layer 20, forming a concave step on the side surface 204.

[0169] (Embodiment 3) The following describes embodiment 3. In the following description of embodiment 3, differences from embodiment 1 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0170] Fig. 8 is a diagram showing a schematic configuration of a battery 300 according to embodiment 3. Specifically, Fig. 8(a) is a cross-sectional view of the battery 300 according to this embodiment, and Fig. 8(b) is a plan view of the battery 300 as seen from the positive side in the z-axis direction. Fig. 8(a) shows a cross section taken along line VIIIa-VIIIa in Fig. 8(b).

[0171] As shown in FIG. 8, the battery 300 includes a power generating element 301 and an insulating member 340. The power generating element 301 has a structure in which two battery cells 1a shown in FIG. 1 are stacked in the z-axis direction. The two battery cells 1a are electrically connected in series. In this embodiment, the positive electrode of one battery cell 1a is directly connected to the negative electrode of the other battery cell 1a. The connected current collector 11 and current collector 21 form a so-called bipolar electrode, with one being a positive electrode and the other being a negative electrode, for example.

[0172] The insulating member 340 contacts and covers the side surfaces 304 of the power generating element 301. The side surfaces 304 of the power generating element 301 correspond to the side surfaces of the two battery cells 1a. The side wall portions 341 of the insulating member 340 continuously cover the side surfaces of the two battery cells 1a together.

[0173] As described above, the battery 300 according to this embodiment has a plurality of stacked battery cells 1a, which makes it possible to achieve improved energy density and increased capacity.

[0174] The two battery cells 1a may be electrically connected in parallel. The power generating element 301 may include three or more battery cells 1a. The three or more battery cells 1a may be connected in parallel or in series. The electrical connection of the three or more battery cells 1a may be a combination of parallel and series connections.

[0175] In the present embodiment, the insulating member 340 may have a configuration similar to that of the insulating members 40A, 40B, 40C and 140 shown in the first to fourth modifications of the first embodiment.

[0176] [Variation 1] Next, a description will be given of Modification 1 of Embodiment 3. In the following description of Modification 1, differences from Embodiment 3 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0177] Fig. 9 is a diagram showing a schematic configuration of a battery 400 according to Modification 1 of Embodiment 3. Specifically, Fig. 9(a) is a cross-sectional view of the battery 400 according to this modification, and Fig. 9(b) is a plan view of the battery 400 as viewed from the positive side in the z-axis direction. Fig. 9(a) shows a cross section taken along line IX-IX in Fig. 9(b).

[0178] 9, a battery 400 according to this modification includes a power generating element 401 and an insulating member 440. Compared to the power generating element 301 according to the third embodiment, the power generating element 401 further includes a conductive adhesive layer 50.

[0179] The conductive adhesive layer 50 is located between the two battery cells 1a and is in contact with each of them. Specifically, the conductive adhesive layer 50 is in contact with the current collector 21 of one battery cell 1a and the current collector 11 of the other battery cell 1a.

[0180] In a plan view, the conductive adhesive layer 50 is smaller than the current collectors 11 and 21. Therefore, a gap is provided between the current collectors 11 and 21 along the end face of the conductive adhesive layer 50. In other words, a step is formed on the side surface 404 of the power generating element 401. In this modification, an insulating member 440 is filled in to fill the step.

[0181] 9(a), the insulating member 440 includes a filling portion 444. The filling portion 444 is a portion that extends inward from the inside of the side wall portion 441 so as to fill the gaps between the battery cells 1a, i.e., the steps on the side surface 404.

[0182] In addition, in this modification, the conductive adhesive layer 50 is formed to be smaller than the current collectors 11 and 21, so that the conductive adhesive layer 50 does not protrude onto the side surfaces of the battery cells 1a, thereby preventing short circuits between the battery cells 1a.

[0183] Furthermore, because the conductive adhesive layer 50 is small, gaps are formed between the battery cells 1a, but these steps can be filled by the filling portions 444 of the insulating member 440. This provides the effect of forming strong anchors of the insulating member 440 between the battery cells 1a, thereby achieving high impact resistance.

[0184] [Variation 2] Next, a description will be given of Modification 2 of Embodiment 3. In the following description of Modification 2, differences from Modification 1 of Embodiment 3 will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0185] Fig. 10 is a diagram showing a schematic configuration of a battery 500 according to Modification 2 of Embodiment 3. Specifically, Fig. 10(a) is a cross-sectional view of the battery 500 according to this modification, and Fig. 10(b) is a plan view of the battery 500 as viewed from the positive side in the z-axis direction. Fig. 10(a) shows a cross section taken along line Xa-Xa in Fig. 10(b).

[0186] 10 , the battery 500 includes a power generating element 501 and an insulating member 540. The power generating element 501 differs from the power generating element 401 according to the first modification in that two battery cells 1a are stacked with their positions shifted. This results in a step being formed on a side surface 504 of the power generating element 501.

[0187] The insulating member 540 is provided to cover the side surface 504 of the power generating element 501, covering any steps. In this modification, the side wall portion 541 of the insulating member 540 is formed with a uniform thickness. That is, the outer surface of the side wall portion 541 is formed along the steps of the side surface 504 of the power generating element 501, and has steps. Also, as in the first modification, the insulating member 540 includes a filling portion 544 that fills the gaps between the battery cells 1a.

[0188] In this way, by stacking the battery cells 1a in a staggered manner and providing the insulating member 540 to cover the resulting steps, the adhesiveness of the insulating member 540 is improved. This prevents the intrusion of air or moisture, improving the environmental resistance of the battery 500 and improving reliability against stresses such as thermal cycles, impacts, and repeated charge and discharge. Furthermore, peeling of the insulating member 540 is prevented even when the insulating member 540 is hardened, further improving adhesiveness reliability.

[0189] The battery cells 1a stacked in a shifted manner may be any battery cells, and a plurality of battery cells 1a may be stacked together in a shifted manner.

[0190] Furthermore, the same effect can be obtained by providing a step on the outer peripheral side surface by changing the size of the battery or power generating element, for example, at the top or bottom.

[0191] The battery cells 1a may also be different in size. For example, the size of one battery cell 1a in a plan view may be larger than the size of the other battery cells 1a in a plan view. As a result, one battery cell 1a protrudes from the other battery cells 1a, forming a convex step on the side surface 504. Alternatively, the size of one battery cell 1a in a plan view may be smaller than the size of the other battery cells 1a in a plan view. As a result, one battery cell 1a is recessed relative to the other battery cells 1a, forming a concave step on the side surface 504.

[0192] [Battery manufacturing method] Next, an example of a method for manufacturing the battery according to each of the above-described embodiments and modifications will be described. Below, a method for manufacturing the battery 100 according to the above-described embodiment 1 shown in FIG. 1 will be described.

[0193] First, a method for manufacturing the battery cell 1a will be described.

[0194] First, pastes to be used for printing the active material layer 12 (specifically, the positive electrode active material layer) and the active material layer 22 (specifically, the negative electrode active material layer) are prepared. As the solid electrolyte raw material used for the mixture of each of the positive electrode active material layer and the negative electrode active material layer, for example, a glass powder of Li2S-P2S5-based sulfide having an average particle size of about 10 μm and containing triclinic crystals as the main component is prepared. As this glass powder, for example, 2×10 -3 S / cm or more 3×10 -3 As the positive electrode active material, for example, a Li·Ni·Co·Al composite oxide (specifically, LiNi 0.8 Co 0.15 Al 0.05 A powder of O2) is used. A paste for a positive electrode active material layer is prepared by dispersing a mixture containing the above-mentioned positive electrode active material and the above-mentioned glass powder in an organic solvent or the like. In addition, as the negative electrode active material, for example, a powder of natural graphite having an average particle size of about 10 μm is used. Similarly, a paste for a negative electrode active material layer is prepared by dispersing a mixture containing the above-mentioned negative electrode active material and the above-mentioned glass powder in an organic solvent or the like.

[0195] Next, copper foil with a thickness of, for example, about 15 μm is prepared as the material to be used for current collector 11 (specifically, a positive electrode current collector) and current collector 21 (specifically, a negative electrode current collector). A paste for a positive electrode active material layer and a paste for a negative electrode active material layer are printed on one surface of each copper foil by screen printing, each in a predetermined shape and with a thickness of about 50 μm to about 100 μm. The paste for a positive electrode active material layer and the paste for a negative electrode active material layer are dried at a temperature in the range of 80°C to 130°C, resulting in a thickness of 30 μm to 60 μm. This results in current collectors on which a positive electrode active material layer and a negative electrode active material layer are formed, i.e., electrode layer 10 (specifically, a positive electrode) and counter electrode layer 20 (specifically, a negative electrode).

[0196] Next, a paste for a solid electrolyte layer is prepared by dispersing the mixture containing the glass powder in an organic solvent or the like. The paste for a solid electrolyte layer is printed, for example, to a thickness of about 100 μm on the surfaces of the active material layers of the positive and negative electrodes using a metal mask. The positive and negative electrodes on which the paste for a solid electrolyte layer is printed are then dried at a temperature in the range of 80°C to 130°C.

[0197] Next, the solid electrolyte printed on the positive electrode active material layer of the positive electrode and the solid electrolyte printed on the negative electrode active material layer of the negative electrode are laminated so as to be in contact with and face each other.

[0198] Next, a pressure die plate was placed on the top surface of the current collector with an elastic modulus of 5 × 10 6 An elastic sheet having a pressure of about 300 MPa is inserted. The thickness of the elastic sheet is, for example, 70 μm. Thereafter, the pressure mold plate is pressed at a pressure of 300 MPa for 90 seconds while being heated to 50°C.

[0199] Through the above steps, the battery cell 1a is manufactured.

[0200] When stacking multiple battery cells 1a, a thermosetting conductive paste containing silver particles is screen-printed to a thickness of approximately 30 μm on the surface of the current collector to which the battery cells 1a are to be joined, and another battery is placed in a predetermined position and pressed. 2 The mixture is left standing while applying a pressure of 100°C to 300°C for 60 minutes to undergo a heat curing treatment, and then cooled to room temperature. This completes the formation of the power generating element 301, 401, or 501 including multiple battery cells 1a.

[0201] Next, a method for forming the insulating member 40 will be described. The insulating member 40 can be formed using, for example, an edge coating method, which is one of the edge electrode formation methods used for chip components such as MLCCs (Multilayer Ceramic Capacitors). A specific example of the edge coating method will be described below with reference to FIG. 11.

[0202] 11 is a cross-sectional view illustrating a method for manufacturing a battery according to an embodiment of the present invention, specifically showing an example of a method for forming an insulating member 40 on a power generating element 1.

[0203] 11(a), a thin film of resin material 40a is disposed on a predetermined flat plate 90. The flat plate 90 is, for example, a metal plate. The resin material 40a is a material that becomes the insulating member 40, and is, for example, an epoxy liquid.

[0204] As shown in FIG. 11(b), the side surface 4 of the power generating element 1 is immersed in the resin material 40a. Specifically, the side surface 4 of the power generating element 1 is pressed against the resin material 40a. As a result, as shown in FIG. 11(c), the resin material 40a adheres to the side surface 4 of the power generating element 1. The power generating element 1 is rotated to adhere the resin material 40a over the entire side surface 4. The adhered resin material 40a is cured to form the insulating member 40.

[0205] The application state of the resin material 40a also varies depending on the viscosity of the resin material 40a or the wettability of the side surface 4 and the main surfaces 2 and 3 of the power generating element 1. For this reason, the viscosity of the resin material 40a used or the state of the side surface 4 and the main surfaces 2 and 3 of the power generating element 1 may be adjusted. For example, by providing appropriate roughness to the side surface 4 and the main surfaces 2 and 3, the surface energy is dispersed, improving wettability and enabling better control of the application shape of the resin material 40a.

[0206] For example, simply polishing the chamfered surface with #10000 abrasive paper can form a finely textured surface with a surface roughness Rz of approximately 0.5 μm. Meanwhile, the end faces of the current collectors 11 and 21 are also polished, exposing metal surfaces free of adsorbing components. Therefore, these end faces tend to repel the resin material 40a. However, by preforming a finely textured bonding surface, this repelling of the resin material 40a is suppressed, facilitating application. This allows the resin material 40a to be applied precisely to the desired application area. Furthermore, the increased bonding area due to the surface roughness further strengthens the anchoring effect of the insulating member 40, thereby improving the bonding strength between the insulating member 40 and the power generating element 1.

[0207] For example, by forming minute irregularities along the edges of the main surfaces 2 and 3, an insulating member 40A having a wraparound portion 42A as shown in Fig. 2 can be formed. Furthermore, with a typical edge coating method, the thickness of the wraparound portion 42B and corner portions 44a, 44b, 44c, and 44d increases, as in insulating member 40B shown in Fig. 3. By removing the thickened portions by polishing or the like, an insulating member 40 having a uniform thickness can be formed as shown in Fig. 1.

[0208] Alternatively, instead of using liquid epoxy, powder epoxy may be applied and thermally cured to form insulating member 40. Of course, side wall portion 41 and wraparound portions 42 and 43 may be formed separately and individually.

[0209] Through the above steps, the battery 100 can be manufactured.

[0210] The method and order of forming the battery are not limited to the above example.

[0211] For example, an insulating resin material may be applied by screen printing to the side surface 4 of the power generating element 1. The resin material applied by screen printing is cured to form the insulating member 40C shown in FIG.

[0212] Furthermore, for example, in the case of the power generating element 301, 401, or 501 including multiple battery cells 1a, the multiple battery cells 1a may be stacked, and then an insulating material may be applied to the side surface 4. Alternatively, the insulating material may be applied to each battery cell 1a, and then the multiple battery cells 1a to which the insulating material has been applied may be stacked.

[0213] In the above-described manufacturing method, the positive electrode active material layer paste, the negative electrode active material layer paste, the solid electrolyte layer paste, and the conductor paste are applied by printing, but the present invention is not limited to this. Examples of printing methods that may be used include doctor blade printing, calendar printing, spin coating, dip coating, inkjet printing, offset printing, die coating, and spray printing.

[0214] In the above-described manufacturing method, a thermosetting conductive paste containing silver metal particles is used as an example of the conductive paste, but this is not limiting. The resin used in the thermosetting conductive paste may be any resin that functions as a binder for adhesion, and may be selected appropriately depending on the manufacturing process being employed, such as printability and applicability. Examples of resins used in the thermosetting conductive paste include thermosetting resins. Examples of thermosetting resins include: (i) amino resins such as urea resin, melamine resin, and guanamine resin; (ii) epoxy resins such as bisphenol A, bisphenol F, phenol novolac, and alicyclic; (iii) oxetane resin; (iv) phenolic resins such as resol and novolac; and (v) silicone-modified organic resins such as silicone epoxy and silicone polyester. Only one of these materials may be used as the resin, or two or more of these materials may be used in combination.

[0215] (Other embodiments) While the battery and its manufacturing method according to the present disclosure have been described above based on the embodiments, the present disclosure is not limited to these embodiments. As long as they do not deviate from the gist of the present disclosure, various modifications conceivable by those skilled in the art to the respective embodiments and other forms constructed by combining some of the components of different embodiments are also included within the scope of the present disclosure.

[0216] For example, in the above embodiment, the wraparound portion 42 extending from the side surface 4 to the main surface 2 and the wraparound portion 43 extending from the side surface 4 to the main surface 3 have the same shape and size, but this is not limited to this. The wraparound portion 42 and the wraparound portion 43 may have different shapes and sizes. For example, the insulating member of the battery may include one selected from wraparound portions 42, 42A, 42B, 42C, and 142, and one selected from wraparound portions 43, 43A, 43B, 43C, and 143.

[0217] Furthermore, in each embodiment and each modified example, the side wall portion and the wraparound portion may have different hardnesses, for example, the side wall portion and the wraparound portion may be formed using different materials.

[0218] Furthermore, for example, the insulating member does not have to cover the entire side surface 4 of the power-generating element 1, and part of the side surface 4 may be exposed. This can improve the reliability of the battery compared to when no insulating member is provided at all. Furthermore, the wraparound portion is provided in an annular shape around the entire circumference of the main surface 2 or the main surface 3, but it may not be provided in part. For example, the wraparound portion may be provided intermittently along the circumference of the main surface 2 or the main surface 3. This can improve the reliability of the battery compared to when no wraparound portion is provided at all.

[0219] Furthermore, for example, the insulating member does not have to contain resin, and may be formed using an insulating inorganic material.

[0220] Furthermore, for example, at least one of the electrode layer and the counter electrode layer may not include a current collector. For example, when a plurality of electrode cells are stacked, one of the electrode layers or counter electrode layers of adjacent electrode cells may not include a current collector. For example, active material layers may be provided on both sides of one current collector so that one current collector is shared by two electrode cells.

[0221] Also, for example, the outer surface of the wraparound portion does not have to be rounded. The outer surface of the wraparound portion may include a plane parallel to the main surface 2 and a plane parallel to the side surface 4, and these two planes may be connected at a right angle.

[0222] Furthermore, various modifications, substitutions, additions, omissions, etc. can be made to each of the above-described embodiments within the scope of the claims or their equivalents. [Industrial Applicability]

[0223] The battery according to the present disclosure can be used, for example, as a secondary battery such as an all-solid-state battery used in various electronic devices or automobiles. [Explanation of symbols]

[0224] 1, 201, 301, 401, 501 Power generation elements 1a, 201a battery cells 2nd and 3rd main surfaces 4, 204, 304, 404, 504 Side 5, 5a, 5b, 5c, 5d ridgeline 6a, 6b, 6c, 6d corners 10 electrode layer 11, 21 Current collector 12, 22 Active material layer 13 particles 20 Opposite Layer 30 Solid electrolyte layer 40, 40A, 40B, 40C, 140, 240, 340, 440, 540 Insulating material 40a resin material 41, 41C, 141, 241, 341, 441, 541 Side wall part 42, 42A, 42B, 42C, 43, 43A, 43B, 43C, 142, 143 Wrapping portions 42Aa, 42Ab, 42Ac, 42Ad Ends 44a, 44b, 44c, 44d Corners 50 Conductive adhesive layer 90 Flat plate 100, 101, 102, 103, 104, 200, 300, 400, 500 Batteries 140a First film 140b Second film 444, 544 Filling portions

Claims

1. a power generating element having at least one battery cell including a positive electrode, a negative electrode, and a solid electrolyte layer; an insulating member that contacts and covers the side surface of the power generating element; Equipped with the insulating member has a wraparound portion that is continuous from the side surface to the main surface of the power-generating element and that contacts and covers each of the side surface and the main surface, The wraparound portion has a shape that is curved convexly toward the center of the main surface in a plan view of the main surface. battery.

2. The outer surface of the wraparound portion is rounded. The battery of claim 1 .

3. the insulating member has a sidewall portion that contacts and covers the center of the side surface, The thickness of the wraparound portion is greater than the thickness of the side wall portion. The battery according to claim 1 or 2.

4. the insulating member has a sidewall portion that contacts and covers the center of the side surface, The thickness of the side wall portion is greater than the thickness of the wraparound portion. The battery according to claim 1 or 2.

5. The wraparound portion is provided at least at one of the four corners of the main surface. The battery of any one of claims 1 to 4.

6. The side surface has a step. The battery of any one of claims 1 to 5.

7. At least one of the positive electrode and the negative electrode is A current collector; an active material layer located between the current collector and the solid electrolyte layer, the main surface is a surface of the current collector opposite to a surface on which the solid electrolyte layer is provided; The battery of any one of claims 1 to 6.

8. the insulating member is softer than the solid electrolyte layer and the active material layer; The battery of claim 7.

9. the insulating member is filled in an end portion of at least one of the solid electrolyte layer and the active material layer that is in contact with the side surface; The battery according to claim 7 or 8.

10. The insulating member includes a resin.

10. The battery of claim 1.

11. A power generating element having at least one battery cell including a positive electrode, a negative electrode, and a solid electrolyte layer; an insulating member that contacts and covers the side surface of the power generating element; Equipped with the insulating member has a wraparound portion that is continuous from the side surface to the main surface of the power-generating element and that contacts and covers each of the side surface and the main surface, the insulating member includes a resin, the insulating member has a laminated structure of a plurality of insulating films; battery.

12. the insulating films each contain a different resin material; The battery of claim 11.

13. The plurality of insulating films have different hardnesses.

13. The battery of claim 11 or 12.

14. the plurality of insulating films include a first film in contact with the side surface, the first membrane is softer than the solid electrolyte layer; 14. The battery of any one of claims 11 to 13.

15. the first film is softer than the solid electrolyte layer at a temperature equal to or lower than the lower limit of the operating temperature range; 15. The battery of claim 14.

16. The plurality of insulating films are a first film in contact with the side surface; A second film covering the entire surface of the first film opposite to the side surface, 16. The battery of any one of claims 11 to 15.

17. the at least one battery cell is a plurality of battery cells; The plurality of battery cells are stacked.

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

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

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

19. A method for manufacturing a battery according to any one of claims 1 to 18, comprising: The method includes a step of immersing a side surface of a power generating element having at least one battery cell including a positive electrode, a negative electrode, and a solid electrolyte layer in an insulating material; How batteries are manufactured.

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