Battery

Abstract

This battery comprises: a power generation element including a first electrode layer, a second electrode layer, and a solid electrolytic layer positioned between the first electrode layer and the second electrode layer; and an insulating member, wherein at least a portion of corner sections of the power generation element is provided with a chamfered section, and the insulating member covers at least a portion of the chamfered section.

Description

[Technical field]

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

[0002] Patent Document 1 discloses an electricity storage device having a C-shaped corner at the intersection of the side and bottom surfaces of an electrode assembly. Patent Document 2 discloses a battery having an inclined portion in which an active material layer is inclined toward an exposed portion, and an exposed portion at an end of a current collector, and the inclined portion and exposed portion are covered with an insulating member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-32386 A [Patent Document 2] International Publication No. 2015-064586 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a need in the art for highly reliable batteries.

[0005] Therefore, the present disclosure provides a highly reliable battery. [Means for solving the problem]

[0006] A battery according to one aspect of the present disclosure includes a power generating element including a first electrode layer, a second electrode layer, and a solid electrolyte layer located between the first electrode layer and the second electrode layer, and an insulating member, wherein at least a portion of a corner of the power generating element is provided with a chamfered portion, and the insulating member covers at least a portion of the chamfered portion. Effect of the Invention

[0007] According to the present disclosure, a highly reliable battery can be provided. [Brief description of the drawings]

[0008] [Figure 1A] FIG. 1A is a side view showing a schematic configuration of a battery according to an embodiment. [Figure 1B] FIG. 1B is a top view showing a schematic configuration of a battery according to an embodiment. [Figure 1C] FIG. 1C is a diagram for explaining a method of forming a chamfered portion according to an embodiment. [Figure 2A] FIG. 2A is a side view showing a schematic configuration of a battery according to a first modification of the embodiment. [Figure 2B] FIG. 2B is a top view showing a schematic configuration of a battery according to the first modification of the embodiment. [Figure 3A] FIG. 3A is a side view showing a schematic configuration of a battery according to a second modification of the embodiment. [Figure 3B] FIG. 3B is a top view showing a schematic configuration of a battery according to Modification 2 of the embodiment. [Figure 4A] FIG. 4A is a side view showing a schematic configuration of a battery according to a third modification of the embodiment. [Figure 4B] FIG. 4B is a top view showing a schematic configuration of a battery according to Modification 3 of the embodiment. [Figure 5A] FIG. 5A is a side view showing a schematic configuration of a battery according to a fourth modification of the embodiment. [Figure 5B] FIG. 5B is a top view showing a schematic configuration of a battery according to the fourth modification of the embodiment. [Figure 6A] FIG. 6A is a side view showing a schematic configuration of a battery according to a fifth modification of the embodiment. [Figure 6B] FIG. 6B is a top view showing a schematic configuration of a battery according to Modification 5 of the embodiment. [Figure 7A] FIG. 7A is a side view showing a schematic configuration of a battery according to a sixth modification of the embodiment. [Figure 7B] FIG. 7B is a top view showing a schematic configuration of a battery according to Modification 6 of the embodiment. [Figure 8A]FIG. 8A is a side view showing a schematic configuration of a battery according to a seventh modification of the embodiment. [Figure 8B] FIG. 8B is a top view showing a schematic configuration of a battery according to Modification 7 of the embodiment. [Figure 9A] FIG. 9A is a side view showing a schematic configuration of a battery according to an eighth modification of the embodiment. [Figure 9B] FIG. 9B is a top view showing a schematic configuration of a battery according to Modification 8 of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Summary of the Disclosure) A battery in one aspect of the present disclosure includes a power generating element including a first electrode layer, a second electrode layer, and a solid electrolyte layer located between the first electrode layer and the second electrode layer, and an insulating member, wherein at least a portion of a corner of the power generating element is chamfered, and the insulating member covers at least a portion of the chamfered portion.

[0010] As a result, the corners of the power generating element are covered with the insulating material, which can prevent foreign objects from coming into contact with the corners of the power generating element. Also, the corners of the power generating element are prone to deformation during handling of the battery, which can lead to defects such as short circuits, but the insulating material also acts as a protective material and a buffer material. Also, the insulating material covers the chamfered portion, which has a lower surface energy than the corners when no chamfered portion is provided, so the corners are more likely to be covered with the insulating material. This makes it possible to realize a highly reliable battery.

[0011] Furthermore, for example, the shape of the power generating element may be a rectangular parallelepiped.

[0012] This makes it possible to realize a battery in which the corners of the rectangular parallelepiped power generating element are protected.

[0013] Furthermore, for example, the chamfered portions may be located at each of the four corners of the rectangular parallelepiped in a plan view of the power generating element.

[0014] As a result, the four corners of the rectangular parallelepiped, which are particularly susceptible to deformation and peeling due to handling, impact, etc. of the battery, are covered with an insulating material, which makes it possible to suppress the occurrence and spread of peeling at the four corners of the rectangular parallelepiped, as well as deformation due to impact, etc. Thus, a more reliable battery can be realized.

[0015] Furthermore, for example, the chamfered portion may be inclined with respect to the stacking direction in the power generating element.

[0016] This increases the distance on the surface of the power generating element between the main surface of the first electrode layer side and the main surface of the second electrode layer side at the location where the chamfer is provided. This makes it difficult for the part of the power generating element near the main surface of the first electrode layer side and the part of the power generating element near the main surface of the second electrode layer side to come into contact with each other, thereby suppressing short circuits. This makes it possible to realize a more reliable battery.

[0017] Furthermore, for example, the chamfered portion may be a curved surface.

[0018] In this way, by making the chamfered portion a curved surface, the surface area becomes larger compared to when the same area is chamfered to make the chamfered portion flat, and it becomes easier to cover the chamfered portion with the insulating member.

[0019] Also, for example, the first electrode layer may have a current collector and an active material layer located between the current collector and the solid electrolyte layer, the chamfered portion may be provided across the current collector and the active material layer, and the insulating member may cover the current collector and the active material layer at the chamfered portion.

[0020] As a result, the current collector and the active material layer are covered together with the insulating member, which suppresses the occurrence and spread of peeling between the current collector and the active material layer caused by thermal cycles and external impacts, etc., and improves resistance to thermal cycles and impact resistance.

[0021] Also, for example, the chamfered portion may be provided across the current collector, the active material layer, and the solid electrolyte layer, and the insulating member may cover the current collector, the active material layer, and the solid electrolyte layer at the chamfered portion.

[0022] As a result, the current collector, the active material layer, and the solid electrolyte layer are covered collectively by the insulating member, which suppresses the occurrence and spread of peeling between the current collector and the active material layer and between the active material layer and the solid electrolyte layer caused by thermal cycles, external impacts, and the like, and further improves resistance to thermal cycles and impact resistance.

[0023] Also, for example, the insulating member may cover the outer periphery of the chamfered portion.

[0024] This allows the insulating member to wrap around at least one of the top and side surfaces of the power generating element, improving the sealing ability of the insulating member around the outer periphery of the chamfered portion and the adhesion between the insulating member and the power generating element.

[0025] Furthermore, for example, the insulating member may be softer than the first electrode layer, the solid electrolyte layer, and the second electrode layer.

[0026] This makes it easier for the insulating member to absorb stress that occurs at the interface between the insulating member and the chamfered portion due to thermal stress and impact, thereby effectively protecting the power generating element and achieving a more reliable battery.

[0027] For example, the insulating member may include a resin.

[0028] In this way, since the insulating member contains a resin that can be applied and cured, the insulating member that covers the chamfered portion can be easily formed.

[0029] For example, the insulating member may include a structure in which a plurality of insulating films are stacked.

[0030] As a result, by including a structure in which multiple insulating films are stacked, compared to the case in which an insulating member of the same thickness is formed in one layer, multiple thin insulating films are stacked on the chamfered portion, making the insulating member less likely to peel off from the chamfered portion when the insulating member is formed and hardened. In addition, defects such as thin areas due to voids and uneven thickness are less likely to occur in the insulating member, and a dense insulating member is formed. Therefore, a battery with higher reliability can be realized.

[0031] Furthermore, for example, the types of materials contained in the insulating films may be different from each other.

[0032] This allows the properties of a plurality of insulating films made of different materials to be combined, thereby realizing an insulating member with high functionality.

[0033] Furthermore, for example, the hardness of the insulating films may be lower among the insulating films closer to the chamfered portion.

[0034] As a result, since the relatively soft insulating film is located near the chamfered portion of the power generating element, even if the power generating element expands and contracts due to thermal cycling or charging and discharging, the insulating film deforms to easily follow the expansion and contraction, and the insulating member is less likely to peel off from the chamfered portion, thereby achieving a battery with higher reliability.

[0035] Furthermore, for example, the power generating element may have a structure in which a plurality of unit cells, each of which includes the first electrode layer, a solid electrolyte layer, and the second electrode layer, are stacked.

[0036] This makes it possible to realize a highly reliable battery even in the case of a high-capacity or high-voltage stacked battery.

[0037] For example, the solid electrolyte layer may include a solid electrolyte having lithium ion conductivity.

[0038] This makes it possible to realize a highly reliable lithium ion battery that includes a solid electrolyte.

[0039] Hereinafter, the embodiment will be described in detail with reference to the drawings.

[0040] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in an independent claim showing a top concept are described as optional components.

[0041] Furthermore, in this specification, terms indicating the relationship between elements, such as "parallel," terms indicating the shape of an element, such as "cuboid," and numerical ranges are not expressions that only express a strict meaning, but are expressions that include a substantially equivalent range, for example, a difference of about a few percent.

[0042] In addition, the drawings are not necessarily strict illustrations. In the drawings, the same reference numerals are used for substantially the same configurations, and duplicated explanations are omitted or simplified.

[0043] In this specification and the drawings, the x-axis, y-axis, and z-axis indicate 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, unless otherwise specified, the "thickness direction" refers to the direction perpendicular to the surface on which each layer is laminated.

[0044] Furthermore, unless otherwise specified, in this specification, "planar view" means when the battery is viewed along the stacking direction of the power generating element, and "thickness" in this specification means the length of the power generating element and each layer in the stacking direction.

[0045] In this specification, the terms "upper" and "lower" in the battery configuration do not refer to the upper direction (vertically upward) and lower direction (vertically downward) in absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in the stacking configuration. In addition, the terms "upper" and "lower" are applied not only to the case where two components are arranged in close contact with each other and are in contact with each other, but also to the case where two components are arranged with a gap between them and another component is present between the two components.

[0046] (Embodiment) [Battery configuration] First, the configuration of the battery according to this embodiment will be described.

[0047] Fig. 1A is a side view showing a schematic configuration of a battery 1000 according to the present embodiment. Specifically, Fig. 1A is a side view showing the battery 1000 from the negative side in the y-axis direction. Fig. 1B is a top view showing a schematic configuration of the battery 1000 according to the present embodiment. Specifically, Fig. 1B is a plan view showing the battery 1000 from the positive side in the z-axis direction.

[0048] As shown in FIG. 1A and FIG. 1B, the battery 1000 includes a power generating element 500 including an electrode layer 100, a counter electrode layer 200, and a solid electrolyte layer 300 located between the electrode layer 100 and the counter electrode layer 200, and an insulating member 900. A chamfered portion 800 is provided at a corner of the power generating element 500. In other words, the power generating element 500 has the chamfered portion 800 at at least a part of the corner of the power generating element 500. The insulating member 900 covers the chamfered portion 800 and is in contact with the chamfered portion 800. The battery 1000 is, for example, an all-solid-state battery. The electrode layer 100 is an example of a first electrode layer, and the counter electrode layer 200 is an example of a second electrode layer.

[0049] FIG. 1C is a diagram for explaining a method for forming the chamfered portion 800. FIG. 1C shows a side surface of the power generating element 500 before chamfering. The chamfered portion 800 is a surface newly exposed at a corner of the power generating element 500, for example, by cutting the power generating element 500 at the position of the dashed line C1, that is, by chamfering the power generating element 500 at the position of the dashed line C1. As a result, a portion including the apex 500C of the power generating element 500 is removed. The thus formed chamfered portion 800 is covered with an insulating member 900 to form the battery 1000 shown in FIG. 1A and FIG. 1B. The chamfered portion 800 may be a surface newly exposed at a corner of the power generating element 500 by chamfering the power generating element 500 so as to remove a portion including the ridge line.

[0050] 1A and 1B, each of the components of battery 1000 will now be described in detail.

[0051] The power generating element 500 has a structure in which an electrode layer 100, a solid electrolyte layer 300, and a counter electrode layer 200 are laminated in this order. More specifically, the power generating element 500 has a structure in which an electrode collector 110, an electrode active material layer 120, a solid electrolyte layer 300, a counter electrode active material layer 220, and a counter electrode collector 210 are laminated in this order. The shape of the power generating element 500 is a rectangular parallelepiped. The shape of the power generating element 500 is not limited to a rectangular parallelepiped, and may be other shapes such as a cylinder or a polygonal prism. In this specification, the shape being a rectangular parallelepiped means that the general shape is a rectangular parallelepiped, and is a concept that also includes a shape obtained by chamfering a rectangular parallelepiped. The same applies to other shapes expressed in this specification.

[0052] The power generating element 500 contacts the insulating member 900 at the chamfered portion 800. The side and main surfaces (i.e., the upper and lower surfaces) of the power generating element 500 are not covered by the insulating member 900 and are not in contact with the insulating member 900. It is sufficient that at least a portion of the side and main surfaces of the power generating element 500, for example, half or more of the surface of the power generating element 500, are not covered by the insulating member 900, and the side and main surfaces of the power generating element 500 may each have an area that is covered by the insulating member 900 and an area that is not covered by the insulating member 900.

[0053] The electrode layer 100 has an electrode current collector 110 and an electrode active material layer 120 located between the electrode current collector 110 and the solid electrolyte layer 300. The electrode current collector 110 is an example of a current collector, and the electrode active material layer 120 is an example of an active material layer. The electrode active material layer 120 is in contact with the surface of the electrode current collector 110 facing the solid electrolyte layer 300.

[0054] Note that another layer such as a bonding layer made of a conductive material may be provided between the electrode current collector 110 and the electrode active material layer 120. The electrode layer 100 does not need to have the electrode current collector 110. For example, a current collector of another electrode layer 100 or counter electrode layer 200, an electrode for extraction, or a substrate supporting the battery 1000 may function as a current collector for the electrode active material layer 120. In other words, the electrode layer 100 may have only the electrode active material layer 120 out of the electrode current collector 110 and the electrode active material layer 120.

[0055] The counter electrode layer 200 is disposed opposite the electrode layer 100 via the solid electrolyte layer 300, and serves as a counter electrode of the electrode layer 100. The counter electrode layer 200 has a counter electrode current collector 210 and a counter electrode active material layer 220 located between the counter electrode current collector 210 and the solid electrolyte layer 300. The counter electrode active material layer 220 is in contact with the surface of the counter electrode current collector 210 on the solid electrolyte layer 300 side.

[0056] Note that another layer such as a bonding layer made of a conductive material may be provided between the counter electrode current collector 210 and the counter electrode active material layer 220. The counter electrode layer 200 may not have the counter electrode current collector 210, and for example, another electrode layer 100 or a current collector of the counter electrode layer 200, an electrode for extraction, or a substrate supporting the battery 1000 may function as a current collector for the counter electrode active material layer 220. In other words, the counter electrode layer 200 may include only the counter electrode active material layer 220 out of the counter electrode current collector 210 and the counter electrode active material layer 220.

[0057] In this embodiment, for example, one of the electrode layer 100 and the counter electrode layer 200 is a positive electrode layer having a positive electrode active material layer and a positive electrode current collector as the electrode active material layer 120 and the electrode current collector 110, and the other is a negative electrode layer having a negative electrode active material layer and a negative electrode current collector as the counter electrode active material layer 220 and the counter electrode current collector 210. Hereinafter, 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".

[0058] The positive electrode active material layer includes at least a positive electrode active material. That is, the positive electrode active material layer is a layer mainly composed of a positive electrode material such as a positive electrode active material. The positive electrode active material is a material in which metal ions such as lithium (Li) or magnesium (Mg) are inserted 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 positive electrode active material can be appropriately selected according to the type of battery, and a known positive electrode active material can be used. Examples of the positive electrode active material include compounds containing lithium and a transition metal element, and more specifically, oxides containing lithium and a transition metal element, and phosphate compounds containing lithium and a transition metal element. Examples of oxides containing lithium and a transition metal element include LiNi x M 1-xLithium nickel composite oxides such as O2 (where M is at least one element among Co, Al, Mn, V, Cr, Mg, Ca, Ti, Zr, Nb, Mo, and W, and x satisfies 0 < x ≤ 1), layered oxides such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganate (LiMn2O4), and lithium manganate having a spinel structure (LiMn2O4, Li2MnO3, LiMO2), etc. are used. As the phosphate compound containing lithium and a transition metal element, for example, lithium iron phosphate (LiFePO4) having an olivine structure is used. Further, sulfides such as sulfur (S) and lithium sulfide (Li2S) can also be used as the positive electrode active material. In that case, a material coated or added with lithium niobate (LiNbO3) or the like on the positive electrode active material particles can be used as the positive electrode active material. Note that only one of these materials may be used as the positive electrode active material, or two or more of these materials may be combined and used.

[0059] As described above, the positive electrode active material layer only needs to contain at least the positive electrode active material. The positive electrode active material layer may be a composite layer composed of a composite of the positive electrode active material and other additive materials. As the additive materials, for example, solid electrolytes such as inorganic solid electrolytes or sulfide solid electrolytes, conductive aids such as acetylene black, binders for binding such as polyethylene oxide or polyvinylidene fluoride, etc. can be used. By mixing the positive electrode active material with other additive materials such as a solid electrolyte and a conductive aid at a predetermined ratio, the ionic conductivity in the positive electrode active material layer can be improved, and the electron conductivity can also be improved. As the solid electrolyte, for example, the solid electrolyte exemplified as the solid electrolyte of the solid electrolyte layer 300 described later can be used.

[0060] The thickness of the positive electrode active material layer is, for example, 5 μm or more and 300 μm or less.

[0061] The negative electrode active material layer includes at least a negative electrode active material. That is, the negative electrode active material layer is a layer mainly composed of a negative electrode material such as a negative electrode active material. The negative electrode active material is a material in which metal ions such as lithium (Li) or magnesium (Mg) are inserted or removed into or from the crystal structure at a potential lower than that of the positive electrode, and oxidation or reduction occurs accordingly. The type of the negative electrode active material can be appropriately selected according to the type of battery, and a known negative electrode active material can be used. For example, a carbon material such as natural graphite, artificial graphite, graphite carbon fiber, or resin-baked carbon, or an alloy-based material mixed with a solid electrolyte can be used as the negative electrode active material. For example, LiAl, LiZn, Li3Bi, Li3Cd, Li3Sb, Li4Si, Li 4.4 Pb, Li 4.4 Sn, Li 0.17 C, lithium alloys such as LiC6, lithium titanate (Li4Ti5O 12 ), zinc oxide (ZnO) and silicon oxide (SiO x ) and other metal oxides can be used. For the negative electrode active material, only one of these materials may be used, or two or more of these materials may be used in combination.

[0062] As described above, the negative electrode active material layer may include at least the negative electrode active material. The negative electrode active material layer may be a mixture layer composed of a mixture of the negative electrode active material and other additive materials. As the additive materials, for example, a solid electrolyte such as an inorganic solid electrolyte or a sulfide solid electrolyte, a conductive assistant such as acetylene black, and a binding binder such as polyethylene oxide or polyvinylidene fluoride may be used. The negative electrode active material layer can improve the ionic conductivity in the negative electrode active material layer and also improve the electronic conductivity by mixing the negative electrode active material with the solid electrolyte and other additive materials such as the conductive assistant at a predetermined ratio. As the solid electrolyte, for example, a solid electrolyte exemplified as the solid electrolyte of the solid electrolyte layer 300 described later may be used.

[0063] The negative electrode active material layer has a thickness of, for example, 5 μm or more and 300 μm or less.

[0064] The current collector may be made of a material having electrical conductivity, and the material of the current collector is not particularly limited. For example, a foil, plate or mesh made of stainless steel, nickel, aluminum, iron, titanium, copper, palladium, gold and platinum, or an alloy of two or more of these metals, may be used as the current collector. The material of the current collector may be appropriately selected in consideration of the fact that it does not melt or decompose in the manufacturing process, the temperature at which it is used, and the pressure at which it is used, and the battery operating potential and electrical conductivity applied to the current collector. The material of the current collector may also be selected according to the required tensile strength and heat resistance. The current collector may be a high-strength electrolytic copper foil or a clad material in which different metal foils are laminated.

[0065] The thickness of the current collector is, for example, not less than 10 μm and not more than 100 μm.

[0066] The solid electrolyte layer 300 is located between the electrode active material layer 120 and the counter electrode active material layer 220. The solid electrolyte layer 300 contacts the lower surface of the electrode active material layer 120 and the upper surface of the counter electrode active material layer 220.

[0067] The solid electrolyte layer 300 includes at least a solid electrolyte. The solid electrolyte may be any known solid electrolyte for batteries having ion conductivity, and may be, for example, a solid electrolyte that conducts metal ions such as lithium ions and magnesium ions. The solid electrolyte may be appropriately selected according to the type of conductive ions, and may be, for example, an inorganic solid electrolyte such as a sulfide-based solid electrolyte or an oxide-based solid electrolyte. Examples of the sulfide-based solid electrolyte include lithium-containing sulfides such as Li2S-P2S5, Li2S-SiS2, Li2S-B2S3, Li2S-GeS2, Li2S-SiS2-LiI, Li2S-SiS2-Li3PO4, Li2S-Ge2S2, Li2S-GeS2-P2S5, and Li2S-GeS2-ZnS. Examples of the oxide-based solid electrolyte include lithium-containing metal oxides such as Li2O-SiO2 and Li2O-SiO2-P2O5, Li x P y O 1-z N zLithium-containing metal nitrides such as lithium phosphate (Li3PO4), lithium-containing transition metal oxides such as lithium titanium oxide, etc. As the solid electrolyte, only one of these materials may be used, or two or more of these materials may be used in combination.

[0068] In addition to the solid electrolyte, the solid electrolyte layer 300 may contain an adhesive binder such as polyethylene oxide or polyvinylidene fluoride.

[0069] The thickness of the solid electrolyte layer 300 is, for example, not less than 5 μm and not more than 150 μm.

[0070] The solid electrolyte layer 300 may be formed as an aggregate of solid electrolyte particles, or may be formed of a sintered structure of the solid electrolyte.

[0071] The chamfered portions 800 are located at the four corners of the rectangular parallelepiped shape of the power generating element 500 in a plan view. Specifically, the chamfered portions 800 are located at the four corners of the upper surface of the power generating element 500. Four chamfered portions 800 are provided on the power generating element 500. The number of chamfered portions 800 is not limited to four, and may be one to three or less, or may be five or more.

[0072] The chamfered portion 800 is provided on the electrode layer 100 in the power generating element 500, specifically, across the electrode current collector 110 and the electrode active material layer 120. The chamfered portion 800 is not provided on the solid electrolyte layer 300. The chamfered portion 800 is covered with an insulating member 900. The chamfered portion 800 is a flat surface inclined with respect to the stacking direction in the power generating element 500. By providing the chamfered portion 800 inclined with respect to the stacking direction across the electrode current collector 110 and the electrode active material layer 120, the distance between the main surface (i.e., upper surface) on the electrode layer 100 side and the main surface (i.e., lower surface) on the counter electrode layer 200 side in the power generating element 500, specifically, between the electrode current collector 110 and the counter electrode current collector 210, is increased. This suppresses short circuits caused by contact between the electrode current collector 110 and the counter electrode current collector 210. Furthermore, the chamfered portion 800 is covered with the insulating member 900, which further suppresses short circuits.

[0073] For example, when the power generating element 500 has a rectangular shape of 150 mm×100 mm in plan view, has a thickness of about 200 μm, and uses an electrode current collector 110 made of copper foil having a thickness of about 15 μm, the chamfered portion 800 is formed by cutting the thickness of the electrode current collector 110 or more, that is, about 15 μm or more, from the upper surface of the power generating element 500. In this way, the chamfered portion 800 inclined with respect to the stacking direction is provided over the electrode current collector 110 and the electrode active material layer 120, so that the end of the electrode current collector 110 at the chamfered portion 800 is located inside and recessed from the side surface of the power generating element 500 in plan view. Furthermore, the end of the electrode current collector 110 is covered with an insulating member 900. This makes it difficult for the electrode current collector 110 to come into contact with other members, thereby suppressing short circuits. The range in which the chamfered portion 800 is provided is set from the viewpoint of battery capacity, for example, so as not to significantly reduce the volume of the power generating element 500. The volume of the power generating element 500 reduced by providing the chamfered portion 800 is, for example, 3% or less, or may be 1% or less, or may be 0.5% or less, of the volume of the power generating element 500 before the chamfered portion 800 is provided.

[0074] The chamfered portion 800 may be provided only on the electrode current collector 110. This can reduce the effect on the battery capacity. The chamfered portion 800 may be provided not only on the electrode current collector 110 and the electrode active material layer 120, but also on the solid electrolyte layer 300 for the purpose of improving reliability, etc., within a range that does not cause problems in manufacturing and battery characteristics.

[0075] Moreover, the chamfered portion 800 is not provided on the counter electrode layer 200. In this manner, since the chamfered portion 800 is provided only on the electrode layer 100, the polarity of the battery 1000 can be determined from the appearance, and therefore, when a module or the like is produced by assembling batteries, the occurrence of electrical connection failures or the like due to assembly with incorrect polarity is suppressed even without going through the work and process of determining the polarity.

[0076] The surface roughness (Rz) of the chamfered portion 800 in contact with the insulating member 900 is, for example, 1 μm or more and 10 μm or less. In this way, the presence of fine irregularities in the chamfered portion 800 increases the bonding area between the chamfered portion 800 and the insulating member 900, and an anchor effect between the chamfered portion 800 and the insulating member 900 is obtained, thereby improving the bonding strength between the chamfered portion 800 and the insulating member 900. For example, by polishing the chamfered portion 800 with a polishing paper of #1200, fine irregularities having a surface roughness (Rz) of 1 μm or more and 2 μm or less can be formed. Also, for example, by polishing the chamfered portion 800 with a polishing paper of #800, fine irregularities having a surface roughness (Rz) of 3 μm or more and 5 μm or less can be formed. The surface roughness (Rz) of the chamfered portion 800 in contact with the insulating member 900 may be 3 μm or more and 10 μm or less. This disperses the surface energy, improving the wettability between the chamfered portion 800 and the insulating member 900, and making the insulating member 900 less likely to be repelled by the chamfered portion 800. This provides the effects of reducing the area of ​​the chamfered portion 800 and enabling the insulating member 900 to be applied accurately to a desired application area.

[0077] The insulating member 900 is bonded to the power generating element 500. Specifically, the insulating member 900 covers the chamfered portions 800, and is bonded to the electrode layer 100 of the power generating element 500 at the chamfered portions 800. The insulating member 900 also covers each of the chamfered portions 800 at the four corners of the power generating element 500 in a planar view. That is, the number of insulating members 900 included in the battery 1000 is four. Note that, among the chamfered portions 800 at the four corners, there may be some chamfered portions 800 that are not covered by the insulating member 900.

[0078] The insulating member 900 covers the ends of the electrode collector 110 and the electrode active material layer 120 exposed at the chamfered portion 800 at the same time, and is joined to the electrode collector 110 and the electrode active material layer 120. This makes it difficult for the electrode collector 110 and the electrode active material layer 120 to peel off from each other. Furthermore, the insulating member 900 covers the electrode active material layer 120, thereby suppressing contact between the active material and foreign matter. Furthermore, the insulating member 900 covers the electrode active material layer 120, thereby suppressing short circuit with the counter electrode layer 200 and characteristic deterioration caused by so-called powder fall, in which powder of the active material is detached. The insulating member 900 is formed, for example, by applying it to the chamfered portion 800. The shape of the insulating member 900 is not particularly limited as long as it covers the chamfered portion 800, and may be a block or a film.

[0079] The insulating member 900 covers the entire surface of each chamfered portion 800. The insulating member 900 covers only the chamfered portion 800 on the surface of the power generating element 500. The insulating member 900 only needs to cover the corners of the power generating element 500 (i.e., the chamfered portion 800) that are prone to deformation and peeling, and insulate the corners of the power generating element 500. The insulating member 900 may cover only a part of the chamfered portion 800, or may cover the power generating element 500 over a wider area than the chamfered portion 800. For example, the insulating member 900 may cover the ridge line from the electrode layer 100 to the counter electrode layer 200. This provides the effect of suppressing peeling of each layer of the power generating element 500.

[0080] For example, as a comparative example, when a battery 1000 without chamfered portion 800 and without covering the corners of power generating element 500 with insulating member 900 is placed on a hot plate heated to 100° C., the upper current collector begins to peel off from the outer periphery due to thermal stress after 5 minutes. On the other hand, when battery 1000 according to the present embodiment is placed on a similar hot plate, no peeling of the current collector occurs, and the peeling suppression effect was confirmed.

[0081] The material of the insulating member 900 may be any material as long as it is an electrical insulator. The insulating member 900 includes, for example, a resin. The insulating member 900 includes, for example, an insulating resin as a main component. Examples of the resin include epoxy resin, acrylic resin, polyimide resin, and silsesquioxane. Specifically, the insulating member 900 uses a coatable resin such as a liquid or powder thermosetting epoxy resin. By applying such a coatable resin in a liquid or powder form to the chamfered portion 800 and thermally curing it, the insulating member 900 can be covered and bonded to the chamfered portion 800.

[0082] The insulating member 900 may be softer than, for example, any of the constituent members of the power generating element 500, specifically, the electrode layer 100, the counter electrode layer 200, and the solid electrolyte layer 300. This allows the insulating member 900 to absorb impacts and the like on the portion where the chamfered portion 800 covered with the insulating member 900 is provided, and protect the power generating element 500. In addition, even in a thermal cycle environment, the relatively soft insulating member 900 absorbs the stress acting on the interface between the insulating member 900 and the chamfered portion 800 due to the difference in the thermal expansion coefficient between the insulating member 900 and the power generating element 500, and therefore adverse effects on the structure of each layer of the battery 1000, such as the occurrence of cracks, can be suppressed. The Young's modulus of the insulating member 900 is, for example, 10 GPa or more and 40 GPa or less. Specifically, the insulating member 900 may be made of an epoxy resin having a Young's modulus in this range. By using the insulating member 900 having such a Young's modulus, the battery 1000 can be appropriately protected.

[0083] Regarding the softness (e.g., elastic modulus such as Young's modulus) of the constituent members of the power generating element 500 and the insulating member 900, a rigid indenter can be applied in the same manner as in measuring Vickers hardness, and the relative relationship in softness between the constituent members of the power generating element 500 and the insulating member 900 can be compared by comparing the size relationship of the traces. For example, when an indenter is pressed against each portion of the cross section of the battery 1000 with the same force, if the insulating member 900 is in a state where it is dented more than any of the constituent materials of the power generating element 500, the insulating member 900 is softer than any of the constituent members of the power generating element 500.

[0084] From the viewpoint of electrical insulation, the thickness of the thickest part of the insulating member 900 may be 10 μm or more, and the thickness of the thinnest part of the insulating member 900 may be 10 μm or more. From the viewpoint of shock absorption, the thickness of the thickest part of the insulating member 900 may be 100 μm or more, and the thickness of the thinnest part of the insulating member 900 may be 100 μm or more. From the viewpoint of blocking air and moisture, the thickness of the thickest part of the insulating member 900 may be 1 mm or more, and the thickness of the thinnest part of the insulating member 900 may be 1 mm or more. The upper limit of the thickness of the insulating member 900 is not particularly limited. The thickness of the insulating member 900 may be set to an appropriate thickness that can achieve both the weight energy density and volume energy density of the battery 1000 and the effect of the insulating member 900. In this specification, the thickness of the insulating member 900 is the length of the insulating member 900 in the normal direction of the chamfered portion 800.

[0085] According to the above configuration, the insulating member 900 covers the corners of the power generating element 500, specifically the chamfered portion 800 provided on the electrode layer 100, and therefore it is possible to suppress short-circuiting between the electrode layer 100 and the counter electrode layer 200, and contact of foreign matter at the corners of the power generating element 500. In addition, the corners of the power generating element 500 are areas that are prone to deformation during handling of the battery 1000, leading to defects such as short-circuiting, but the insulating member 900 also acts as a protective member and a buffer member. This allows the battery to be structurally thinned, which is prone to short-circuiting and breakage, and it is possible to realize a battery 1000 that has high energy density and high reliability.

[0086] Furthermore, the functions of the chamfered portions 800 provided at the corners of the power generating element 500 and the insulating members 900 will be described in more detail.

[0087] With the above configuration, by providing the chamfered portion 800 at the corner of the power generating element 500 and covering the chamfered portion 800 with the insulating member 900, it is possible to solve the problem of the corner of the power generating element 500 being exposed from the insulating member 900. Furthermore, the corner of the power generating element 500, which is easily damaged by impact when handling the battery 1000, is protected by the insulating member 900, and the occurrence of structural defects such as peeling can also be suppressed.

[0088] For example, if the corners of the power generating element 500 are covered with the insulating member 900 by coating or the like without providing the chamfered portion 800, it is difficult to wet the ends of the corners of the power generating element 500, such as the apex and ridges, with the insulating member 900 due to the influence of surface tension. In other words, if the chamfered portion 800 is not provided, the surface energy of the corners of the power generating element 500 is high. For example, the apex or ridges of the corners repel the material of the liquid-based insulating member 900, making it extremely difficult to wet them. Therefore, the insulating member 900 is thinnest at the end of the corners of the power generating element 500, and the corners of the electrode current collector 110 may be exposed. In response to this, by removing the portion where the surface tension is concentrated at one point (i.e., the end of the corner of the electrode current collector 110) by chamfering and dispersing and reducing the surface energy, it becomes possible to cover even the end of the electrode current collector 110 with the insulating member 900.

[0089] That is, by chamfering the four corners of the power generating element 500 in a plan view of the power generating element 500, for example, the portions including the ends (vertices) of the four corners of the electrode current collector 110, which are prone to short-circuiting, delamination, and deformation, the surface energy of the portions can be dispersed, and the corners of the power generating element 500 can be covered with the insulating member 900. This solves the problems that arise when the four corners of the power generating element are exposed, and a highly reliable battery 1000 can be realized without impairing the battery characteristics.

[0090] Therefore, the range of the chamfered portion 800 is set, for example, so that the covering insulating member 900 does not expose the chamfered portion 800. For example, the range of the chamfered portion 800 may be set so that the electrode current collector 110 at the chamfered portion, that is, the electrode current collector 110 exposed at the chamfered portion 800, is not exposed by the insulating member 900 from the main surface (i.e., the upper surface) in a top view in the stacking direction of the power generating element 500 to the side surface. In other words, this means that the surface energy of the surface covered with the insulating member 900 is smaller than that of the edge of the corner of the power generating element 500 before chamfering.

[0091] The application state of the insulating member 900 also varies depending on the viscosity and surface tension of the material of the insulating member 900, and the wettability of the surface of the power generating element 500. For this reason, the range of the chamfered portion 800 may be set in accordance with the material of the insulating member 900 used and the material and surface of the power generating element 500 so that the corners of the power generating element 500 are not exposed.

[0092] When the configuration of battery 1000 according to the present embodiment is compared with the configurations of the batteries described in Patent Documents 1 and 2, there are the following differences.

[0093] Patent Document 1 describes a storage battery in which a C portion is provided in an electrode assembly and an insulating sheet that insulates the electrode assembly from a case that houses the electrode assembly. However, the insulating sheet is a bag-shaped sheet that houses the electrode assembly, and is not fixedly joined to the electrode assembly. For this reason, the insulating sheet moves and shifts due to vibration or impact, which is likely to cause a short circuit. In addition, the electrode assembly does not have a surface that is inclined with respect to the lamination direction. For this reason, when the battery is thinned, the distance between the positive and negative electrode collectors is likely to be narrowed, making it difficult to suppress a short circuit. In addition, since it is not a battery having a solid electrolyte layer, the insulating sheet is not fixed to the positive electrode, the negative electrode, and the separator, and its purpose and configuration are different from those of the present disclosure.

[0094] Patent Document 2 discloses a battery having an inclined portion where an active material layer is inclined toward an exposed portion, and an exposed portion where a part of a current collector is exposed, and the inclined portion and the exposed portion are covered with an insulating material. However, the current collector is exposed at the end, and the configuration is completely different from the configuration of the present embodiment related to a battery having a solid electrolyte layer, in which the corners of a power generating element 500 including an electrode current collector 110 and the like are chamfered. For this reason, when a battery having a solid electrolyte layer has such a configuration, the exposed end of the current collector is not fixed, and deformation caused by the application of stress causes damage around the end of the current collector and peeling between the current collector and the separator (solid electrolyte layer), so that the configuration is not practical, as damage and interlayer peeling easily occur.

[0095] In contrast, the battery 1000 according to the present embodiment does not cause the above-mentioned problems. Furthermore, Patent Documents 1 and 2 do not disclose or suggest the battery described in the present embodiment in which at least a part of the corner of the power generating element 500 has a chamfered portion 800 and the chamfered portion 800 is covered with an insulating member 900.

[0096] [Variations] In the following, a number of modified examples of the embodiment will be described. In the following description of the modified examples, the differences between the embodiment and the modified examples will be mainly described, and descriptions of commonalities between the embodiment and the modified examples will be omitted or simplified.

[0097] (1) Variation 1 First, the first modified example of the embodiment will be described.

[0098] Fig. 2A is a side view showing a schematic configuration of a battery 1100 according to a first modified example of the embodiment. Specifically, Fig. 2A is a side view showing the battery 1100 from the negative side in the y-axis direction. Fig. 2B is a top view showing a schematic configuration of the battery 1100 according to the first modified example of the embodiment. Specifically, Fig. 2B is a plan view showing the battery 1100 from the positive side in the z-axis direction.

[0099] 2A and 2B, the battery 1100 according to the first modification of the embodiment differs from the battery 1000 according to the embodiment in that the battery 1100 includes a power generating element 501 instead of the power generating element 500. The power generating element 501 differs from the power generating element 500 in that the four corners of the power generating element 501 on the counter electrode layer 200 side are also provided with chamfered portions 801 covered with insulating members 901.

[0100] The battery 1100 includes a power generating element 501, and insulating members 900 and 901. Chamfered portions 800 and 801 are provided at corners of the power generating element 501. The insulating member 900 covers the chamfered portion 800 and is in contact with the chamfered portion 800. The insulating member 901 covers the chamfered portion 801 and is in contact with the chamfered portion 801.

[0101] The chamfered portions 801 are located at the four corners of the rectangular parallelepiped shape of the power generating element 501 in a plan view. Specifically, the chamfered portions 801 are located at the four corners of the lower surface of the power generating element 501. Four chamfered portions 801 are provided on the power generating element 501. Note that the number of chamfered portions 801 is not limited to four, and may be one to three or less, or may be five or more.

[0102] The chamfered portion 801 is provided in the counter electrode layer 200 of the power generating element 501, and specifically, is provided across the counter electrode current collector 210 and the counter electrode active material layer 220. The chamfered portion 801 is a flat surface that is inclined with respect to the stacking direction in the power generating element 501. The entire surface of the chamfered portion 801 is covered with an insulating member 901.

[0103] The insulating member 901 is bonded to the power generating element 501. Specifically, the insulating member 901 covers the chamfered portion 801, and is bonded to the counter electrode layer 200 of the power generating element 501 at the chamfered portion 801. The insulating member 901 also covers each of the chamfered portions 801 at the four corners of the power generating element 501 in a planar view. That is, the battery 1100 includes four insulating members 901. Note that, among the chamfered portions 801 at the four corners, there may be some chamfered portions 801 that are not covered by the insulating member 901.

[0104] At the chamfered portion 801, the insulating member 901 collectively covers the end portions of the counter electrode collector 210 and the counter electrode active material layer 220 exposed at the chamfered portion 801, and is bonded to the counter electrode collector 210 and the counter electrode active material layer 220, respectively. This makes it difficult for the counter electrode collector 210 and the counter electrode active material layer 220 to peel off from each other. Furthermore, by covering the counter electrode active material layer 220, the insulating member 901 can suppress contact between the active material and foreign matter. Furthermore, by covering the counter electrode active material layer 220, the insulating member 901 can suppress short-circuiting with the electrode layer 100 and deterioration of characteristics due to so-called powder falloff, in which powder of the active material is detached.

[0105] With this configuration, the chamfered portions 800 and 801 provided at the four corners of the upper and lower surfaces of the power generating element 501, i.e., the four corners of the electrode layer 100 and the counter electrode layer 200, and the insulating members 900 and 901 can prevent foreign matter from coming into contact with the corners of the power generating element 501. In addition, the corners of the power generating element 501, which are prone to deformation during handling of the battery 1100 and cause defects such as short circuits, are effectively protected. This makes it possible to realize a battery 1100 with even higher reliability. In addition, because the corners of the power generating element 501 are effectively protected, the battery can be made even thinner.

[0106] (2) Variation 2 Next, a second modification of the embodiment will be described.

[0107] Fig. 3A is a side view showing a schematic configuration of a battery 1200 according to a second modification of the embodiment. Specifically, Fig. 3A is a side view showing the battery 1200 from the negative side in the y-axis direction. Fig. 3B is a top view showing a schematic configuration of the battery 1200 according to the second modification of the embodiment. Specifically, Fig. 3B is a plan view showing the battery 1200 from the positive side in the z-axis direction.

[0108] As shown in Figures 3A and 3B, battery 1200 according to the second embodiment of the present invention differs from battery 1000 according to the embodiment in that, instead of insulating member 900, battery 1200 according to the second embodiment of the present invention is provided with insulating member 902 that covers the outer periphery of chamfered portion 800.

[0109] The battery 1200 includes a power generating element 500 and an insulating member 902. A chamfered portion 800 is provided at a corner of the power generating element 500. The insulating member 902 covers the chamfered portion 800 up to the outside of the outer periphery of the chamfered portion 800 and is in contact with the chamfered portion 800.

[0110] The insulating member 902 is provided so as to wrap around the upper surface and side surface of the power generating element 500. The insulating member 902 is bonded to the surface of the power generating element 500 up to the outside of the outer periphery of the chamfered portion 800. That is, the insulating member 902 is bonded to both the upper surface and side surface of the power generating element 500. Specifically, the insulating member 902 is bonded to the upper surface of the electrode current collector 110 and the side surface of the solid electrolyte layer 300. The insulating member 902 may be provided so as to wrap around only one of the upper surface and the side surface of the power generating element 500.

[0111] By providing the insulating member 902 around the top and side surfaces of the power generating element 500 in this manner, the sealing performance of the outer periphery of the chamfered portion 800 by the insulating member 902 and the adhesion performance of the insulating member 902 to the power generating element 500 are improved. This improves reliability against stress caused by thermal cycles, impacts, and repeated charging and discharging. Furthermore, even against stress during hardening when the insulating member 902 is formed, the stress is distributed to the top and side surfaces of the power generating element 500, so peeling of the insulating member 902 is suppressed. Furthermore, even in an environment where air and moisture are present, their intrusion is suppressed, improving the environmental resistance of the battery. This makes it possible to realize a battery 1200 with even higher reliability.

[0112] (3) Variation 3 Next, a third modified example of the embodiment will be described.

[0113] Fig. 4A is a side view showing a schematic configuration of a battery 1300 according to a third modification of the embodiment. Specifically, Fig. 4A is a side view showing the battery 1300 from the negative side in the y-axis direction. Fig. 4B is a top view showing a schematic configuration of the battery 1300 according to the third modification of the embodiment. Specifically, Fig. 4B is a plan view showing the battery 1300 from the positive side in the z-axis direction.

[0114] 4A and 4B, battery 1300 according to the third modification of the embodiment differs from battery 1000 according to the embodiment in that it includes a power generating element 503 and an insulating member 903 instead of power generating element 500 and insulating member 900. Also, power generating element 503 differs from power generating element 500 in that it includes a chamfered portion 803 covered with insulating member 903 instead of chamfered portion 800 covered with insulating member 900.

[0115] The battery 1300 includes a power generating element 503 and an insulating member 903. A chamfered portion 803 is provided at the corner of the power generating element 503. The insulating member 903 covers the chamfered portion 803 and is in contact with the chamfered portion 803.

[0116] The chamfered portions 803 are located at the four corners of the rectangular parallelepiped when viewed in a plan view of the rectangular parallelepiped shape of the power generating element 503. The chamfered portions 803 are flat surfaces that are inclined with respect to the stacking direction of the power generating element 503.

[0117] The chamfered portion 803 is provided across the electrode layer 100 and the solid electrolyte layer 300 in the power generating element 503, and more specifically, across the electrode current collector 110, the electrode active material layer 120, and the solid electrolyte layer 300. The chamfered portion 803 is entirely covered with an insulating member 903.

[0118] The insulating member 903 is joined to the power generating element 503. At the chamfered portion 803, the insulating member 903 collectively covers the ends of the electrode current collector 110, the electrode active material layer 120, and the solid electrolyte layer 300 exposed at the chamfered portion 803, and is joined to each of the electrode current collector 110, the electrode active material layer 120, and the solid electrolyte layer 300.

[0119] In this manner, the chamfered portion 803 is provided across the electrode collector 110, the electrode active material layer 120, and the solid electrolyte layer 300, and the insulating member 903 covers the chamfered portion 803, thereby protecting the corners of the power generating element 503 across the electrode collector 110, the electrode active material layer 120, and the solid electrolyte layer 300. In addition, the electrode collector 110, the electrode active material layer 120, and the solid electrolyte layer 300 are collectively covered by the insulating member 903, so that the occurrence and expansion of peeling between the electrode collector 110 and the electrode active material layer 120 and between the electrode active material layer 120 and the solid electrolyte layer 300 caused by thermal cycles, external impacts, and the like can be suppressed. Thus, a more reliable battery 1300 can be realized.

[0120] (4) Variation 4 Next, a fourth modified example of the embodiment will be described.

[0121] Fig. 5A is a side view showing a schematic configuration of a battery 1400 according to a fourth modification of the embodiment. Specifically, Fig. 5A is a side view showing the battery 1400 from the negative side in the y-axis direction. Fig. 5B is a top view showing a schematic configuration of the battery 1400 according to the fourth modification of the embodiment. Specifically, Fig. 5B is a plan view showing the battery 1400 from the positive side in the z-axis direction.

[0122] 5A and 5B, the battery 1400 according to the fourth modification of the embodiment differs from the battery 1000 according to the embodiment in that the battery 1400 includes a power generating element 504 and an insulating member 904 instead of the power generating element 500 and the insulating member 900. The power generating element 504 also differs from the power generating element 500 in that the power generating element 504 includes a chamfered portion 804 covered with an insulating member 904 instead of the chamfered portion 800 covered with the insulating member 900.

[0123] The battery 1400 includes a power generating element 504 and an insulating member 904. A chamfered portion 804 is provided at the corner of the power generating element 504. The insulating member 904 covers the chamfered portion 804 and is in contact with the chamfered portion 804.

[0124] The chamfered portions 804 are located at the four corners of the rectangular parallelepiped when viewed from above with respect to the power generating element 504, which has a rectangular parallelepiped shape. The chamfered portions 804 are curved. This increases the surface area compared to when the same area is chamfered to make the chamfered portion flat, making it easier to cover the chamfered portions 804 with the insulating member 904. At least a portion of the chamfered portions 804 is inclined with respect to the stacking direction in the power generating element 504.

[0125] The insulating member 904 is joined to the power generating element 504. At the chamfered portion 804, the insulating member 904 collectively covers the ends of the electrode current collector 110, the electrode active material layer 120, and the solid electrolyte layer 300 exposed at the chamfered portion 804, and is joined to each of the electrode current collector 110, the electrode active material layer 120, and the solid electrolyte layer 300.

[0126] (5) Variation 5 Next, a fifth modified example of the embodiment will be described.

[0127] Fig. 6A is a side view showing a schematic configuration of a battery 1500 according to a fifth modification of the embodiment. Specifically, Fig. 6A is a side view of the battery 1500 as viewed from the negative side in the y-axis direction. Fig. 6B is a top view showing a schematic configuration of the battery 1500 according to the fifth modification of the embodiment. Specifically, Fig. 6B is a plan view of the battery 1500 as viewed from the positive side in the z-axis direction.

[0128] As shown in Figures 6A and 6B, battery 1500 according to variant 5 of the embodiment differs from battery 1000 according to the embodiment in that, instead of insulating member 900, battery 1500 according to variant 5 includes insulating member 905 including multiple insulating films 905a and 905b.

[0129] The insulating member 905 has a structure in which a plurality of insulating films 905a and 905b are laminated. The insulating film 905a and the insulating film 905b are laminated in this order on the chamfered portion 800 from the chamfered portion 800 side. Note that a non-film-shaped insulating member may be further formed on the plurality of insulating films 905a and 905b.

[0130] The thickness of each of the insulating films 905a and 905b is, for example, 30 μm or less. From the viewpoint of forming a denser insulating member 905, the thickness of each of the insulating films 905a and 905b may be 10 μm or less.

[0131] The number of insulating films included in the insulating member 905 is two, but may be three or more. As a result, the insulating member 905 may have a thickness of 50 μm or more, or may have a thickness of 500 μm or more.

[0132] The laminated structure of the insulating films 905a and 905b in the insulating member 905 is formed by applying a resin such as an epoxy resin to the chamfered portion 800 multiple times. Such a laminated structure of the insulating films 905a and 905b of the insulating member 905 can be observed by general observation such as an optical microscope or a scanning electron microscope (SEM) of a polished cross section. In this way, by laminating the insulating films 905a and 905b on the chamfered portion 800, defects such as thin parts due to voids and uneven thickness are unlikely to occur, and a dense and strong insulating member 905 is formed. In addition, compared to the case where the insulating member 905 of the same thickness is formed in one layer, a plurality of thin insulating films 905a and 905b are laminated on the chamfered portion 800. Therefore, the stress generated when the insulating member 905 is formed and hardened is reduced, and the insulating member 905 is unlikely to peel off from the chamfered portion 800.

[0133] The types of materials contained in the insulating films 905a and 905b may be different from each other. As a result, the insulating member 905 includes the insulating films 905a and 905b with different properties, and therefore the insulating member 905 with high functionality can be realized. In this specification, the different types of materials means that, when the material is a resin, at least one of the molecular structure, molecular composition, and molecular weight is substantially different (for example, the product or manufacturing grade is different). Also, the types of materials contained in the insulating films 905a and 905b may be the same.

[0134] The hardness of the insulating films 905a and 905b may be lower for the insulating film 905a closer to the chamfered portion 800. In other words, the hardness of the insulating film 905a closer to the chamfered portion 800 than the insulating film 905b may be lower than that of the insulating film 905b. In this way, since the relatively soft insulating film 905a is located near the chamfered portion 800 of the power generating element 500, even if the power generating element 500 expands and contracts due to a cooling / heating cycle or charge / discharge, the insulating film 905a deforms and easily follows the expansion and contraction, and the insulating member 905 is less likely to peel off from the chamfered portion 800.

[0135] Furthermore, the curing temperature, such as the thermosetting temperature, the glass transition point, or the melting point, of the insulating films 905a and 905b may be higher for the insulating film 905a closer to the chamfered portion 800. This makes it difficult for the insulating film 905a formed first to deteriorate due to heat during the formation of the insulating film 905b.

[0136] (6) Variation 6 Next, a sixth modified example of the embodiment will be described.

[0137] Fig. 7A is a side view showing a schematic configuration of a battery 1600 according to a sixth modification of the embodiment. Specifically, Fig. 7A is a side view showing the battery 1600 from the negative side in the y-axis direction. Fig. 7B is a top view showing a schematic configuration of the battery 1600 according to the sixth modification of the embodiment. Specifically, Fig. 7B is a plan view showing the battery 1600 from the positive side in the z-axis direction.

[0138] 7A and 7B, the battery 1600 according to the sixth modification of the embodiment differs from the battery 1000 according to the embodiment in that the battery 1600 includes a power generating element 506 and an insulating member 906 instead of the power generating element 500 and the insulating member 900. The power generating element 506 also differs from the power generating element 500 in that the power generating element 506 includes a chamfered portion 806 covered with an insulating member 906 instead of the chamfered portion 800 covered with an insulating member 900.

[0139] The battery 1600 includes a power generating element 506 and an insulating member 906. A chamfered portion 806 is provided at the corner of the power generating element 506. The insulating member 906 covers the chamfered portion 806 and is in contact with the chamfered portion 806.

[0140] The chamfered portions 806 are located on two opposing sides of the rectangular parallelepiped in a plan view of the power generating element 506. The chamfered portions 806 are flat surfaces that are inclined with respect to the stacking direction of the power generating element 506. Two chamfered portions 806 are provided on the power generating element 506. The chamfered portions 806 may be located on one side of the rectangular parallelepiped or on three or more sides of the rectangular parallelepiped in a plan view of the power generating element 506.

[0141] The chamfered portion 806 is provided in the electrode layer 100 of the power generating element 506, and specifically, is provided across the electrode current collector 110 and the electrode active material layer 120. The entire surface of the chamfered portion 806 is covered with an insulating member 906. The chamfered portion 806 may be provided only in the electrode current collector 110, or may be provided across the electrode current collector 110, the electrode active material layer 120, and the solid electrolyte layer 300.

[0142] The insulating member 906 is bonded to the power generating element 506. Specifically, the insulating member 906 covers the chamfered portions 806, and is bonded to the electrode layer 100 of the power generating element 506 at the chamfered portions 806. The insulating member 906 also covers each of the chamfered portions 806 on two sides of the power generating element 506 in a planar view. That is, the number of insulating members 906 included in the battery 1600 is two. Note that, among the chamfered portions 806 on the two sides, there may be some chamfered portions 806 that are not covered by the insulating member 906.

[0143] At the chamfered portion 806 , the insulating member 906 collectively covers the ends of the electrode current collector 110 and the electrode active material layer 120 exposed at the chamfered portion 806 , and is joined to the electrode current collector 110 and the electrode active material layer 120 .

[0144] In this way, the chamfered portion 806 is provided on the side of a rectangular parallelepiped in a plan view of the power generating element 506, and the chamfered portion 806 is covered with the insulating member 906, so that the entire side of the power generating element 506 is protected.

[0145] (7) Variation 7 Next, a seventh modification of the embodiment will be described.

[0146] Fig. 8A is a side view showing a schematic configuration of a battery 1700 according to the seventh modification of the embodiment. Specifically, Fig. 8A is a side view showing the battery 1700 from the negative side in the y-axis direction. Fig. 8B is a top view showing a schematic configuration of the battery 1700 according to the seventh modification of the embodiment. Specifically, Fig. 8B is a plan view showing the battery 1700 from the positive side in the z-axis direction.

[0147] 8A and 8B, battery 1700 according to the seventh modification of the embodiment differs from battery 1000 according to the embodiment in that it includes a power generating element 507 and an insulating member 907 instead of power generating element 500 and insulating member 900. Also, power generating element 507 differs from power generating element 500 in that it includes a chamfered portion 807 covered with insulating member 907 instead of chamfered portion 800 covered with insulating member 900.

[0148] The battery 1700 includes a power generating element 507 and an insulating member 907. A chamfered portion 807 is provided at the corner of the power generating element 507. The insulating member 907 covers the chamfered portion 807 and is in contact with the chamfered portion 807.

[0149] Chamfered portions 807 are located at each of the four corners of the rectangular parallelepiped shape of power generating element 507 when viewed in a plan view. Chamfered portions 807 are also flat surfaces parallel to the stacking direction of power generating element 507. That is, chamfered portions 807 are located at each of the four sides of the rectangular parallelepiped of power generating element 507 that are parallel to the stacking direction of power generating element 507.

[0150] The chamfered portion 807 is provided across the electrode layer 100, the solid electrolyte layer 300, and the counter electrode layer 200 in the power generating element 507, and more specifically, across the electrode current collector 110, the electrode active material layer 120, the solid electrolyte layer 300, the counter electrode active material layer 220, and the counter electrode current collector 210. The chamfered portion 807 is entirely covered with an insulating member 907.

[0151] The insulating member 907 is bonded to the power generating element 507. At the chamfered portion 807, the insulating member 907 collectively covers the ends of the electrode collector 110, the electrode active material layer 120, the solid electrolyte layer 300, the counter electrode active material layer 220, and the counter electrode collector 210 exposed at the chamfered portion 807, and is bonded to each of the electrode collector 110, the electrode active material layer 120, the solid electrolyte layer 300, the counter electrode active material layer 220, and the counter electrode collector 210. This suppresses peeling between the layers constituting the power generating element 507.

[0152] In this way, the chamfered portion 807 is located on a side of a rectangular parallelepiped parallel to the stacking direction of the power generating element 507, and the insulating member 907 covers the chamfered portion 807, thereby protecting the entire side of the rectangular parallelepiped parallel to the stacking direction of the power generating element 507. This makes it possible to realize a more reliable battery 1700.

[0153] (8) Variation 8 Next, an eighth modification of the embodiment will be described.

[0154] Fig. 9A is a side view showing a schematic configuration of a battery 1800 according to an eighth modification of the embodiment. Specifically, Fig. 9A is a side view showing the battery 1800 from the negative side in the y-axis direction. Fig. 9B is a top view showing a schematic configuration of the battery 1800 according to the eighth modification of the embodiment. Specifically, Fig. 9B is a plan view showing the battery 1800 from the positive side in the z-axis direction.

[0155] 9A and 9B, battery 1800 according to the eighth modification of the embodiment differs from battery 1000 according to the embodiment in that battery 1800 includes a power generating element 508 instead of power generating element 500. In addition, power generating element 508 includes a plurality of unit cells 408a and 408b each having a configuration similar to that of power generating element 500.

[0156] Battery 1800 includes power generating element 508 including a structure in which multiple unit cells 408a and 408b are stacked, and insulating members 900 and 901. Chamfered portions 800 and 801 are provided at corners of power generating element 508. Insulating member 900 covers chamfered portion 800 and is in contact with chamfered portion 800. Insulating member 901 covers chamfered portion 801 and is in contact with chamfered portion 801.

[0157] The power generating element 508 includes a structure in which two unit cells 408a and 408b, each of which has the same configuration as the power generating element 500 shown in FIG. 1A and FIG. 1B, are stacked in series in the z-axis direction. Each of the unit cells 408a and 408b includes an electrode layer 100, a counter electrode layer 200, and a solid electrolyte layer 300 located between the electrode layer 100 and the counter electrode layer 200, as in the power generating element 500. In the power generating element 508, the counter electrode current collector 210 of the unit cell 408a and the electrode current collector 110 of the unit cell 408b are electrically connected. This forms a bipolar electrode in which the counter electrode layer 200 and the electrode layer 100 are connected via the counter electrode current collector 210 and the electrode current collector 110. The unit cells 408a and 408b are bonded together by a conductive adhesive such as a thermosetting conductive paste. The number of unit cells included in the power generating element 508 is two, but the power generating element 508 may have a structure in which three or more unit cells are stacked.

[0158] The chamfered portions 800 are located at the four corners of the rectangular parallelepiped shape of the power generating element 508 in a plan view. Specifically, the chamfered portions 800 are located at the four corners of the upper surface of the power generating element 508. The chamfered portions 800 are provided in the electrode layer 100 of the upper unit cell 408a.

[0159] The chamfered portions 801 are located at the four corners of the rectangular parallelepiped shape of the power generating element 508 in a plan view. Specifically, the chamfered portions 801 are located at the four corners of the lower surface of the power generating element 508. The chamfered portions 801 are provided in the counter electrode layer 200 of the lower unit cell 408b.

[0160] In this manner, even in the stacked battery 1800 in which a plurality of unit cells 408a and 408b are stacked, the power generating element 508 is provided with the chamfered portion 800 covered with the insulating member 900 and the chamfered portion 801 covered with the insulating member 901, so that a high-voltage and highly reliable stacked battery 1800 can be realized.

[0161] In this modification, the counter electrode layer 200 of the upper unit cell 408a and the electrode layer 100 of the lower unit cell 408b constituting the bipolar electrode are not provided with a chamfered portion, but may be provided with a chamfered portion. By providing the bipolar electrode portion with a chamfered portion covered with an insulating material, it is possible to suppress short circuits between the upper and lower unit cells, and a highly reliable stacked battery can be realized.

[0162] Furthermore, the unit cells 408a and 408b may be stacked so as to be electrically connected in parallel, in which case a high-capacity and highly reliable stacked battery can be realized.

[0163] [Battery manufacturing method] Next, an example of a method for manufacturing a battery according to the present embodiment will be described. Below, a method for manufacturing a battery 1800 according to the eighth modified example of the above-mentioned embodiment will be described. In addition, in the following description of the manufacturing method, a case will be described in which the electrode layer 100 is a positive electrode layer having a positive electrode active material layer and a positive electrode current collector as the electrode active material layer 120 and the electrode current collector 110, and the counter electrode layer 200 is a negative electrode layer having a negative electrode active material layer and a negative electrode current collector as the counter electrode active material layer 220 and the counter electrode current collector 210.

[0164] First, pastes are prepared for use in printing the electrode active material layer 120 and the counter electrode active material layer 220. As the solid electrolyte raw material used for the mixture of the electrode active material layer 120 and the counter electrode active material layer 220, for example, a glass powder of Li2S-P2S5-based sulfide mainly composed of triclinic crystals and having an average particle size of about 10 μm is prepared. As the glass powder, for example, 2 to 3×10 -3 As the positive electrode active material, for example, a glass powder having a high ionic conductivity of about 1.0 S / cm can be used. 0.8 Co 0.15 Al 0.05A powder of O2) is used. A paste for a positive electrode active material layer (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. A paste for a negative electrode active material layer (counter electrode active material layer) is similarly 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.

[0165] Next, for example, copper foil having a thickness of about 15 μm is prepared as a material used for the electrode collector 110 and the counter electrode collector 210. For example, 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 a screen printing method in a predetermined shape and with a thickness of about 50 μm to 100 μm. The paste for a positive electrode active material layer and the paste for a negative electrode active material layer are dried at 80° C. to 130° C. to a thickness of 30 μm to 60 μm. As a result, a collector (copper foil) on which the electrode active material layer 120 and the counter electrode active material layer 220 are formed, that is, the electrode layer 100 and the counter electrode layer 200 are obtained.

[0166] Next, a paste for a solid electrolyte layer is prepared by dispersing the mixture containing the above-mentioned glass powder in an organic solvent or the like. The above-mentioned 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 electrode layer 100 and the counter electrode layer 200 using a metal mask. Thereafter, the electrode layer 100 and the counter electrode layer 200 on which the paste for a solid electrolyte layer is printed are dried at 80° C. or higher and 130° C. or lower.

[0167] Next, the solid electrolyte printed on the electrode active material layer 120 of the electrode layer 100 and the solid electrolyte printed on the counter electrode active material layer 220 of the counter electrode layer 200 are laminated so as to be in contact with and face each other.

[0168] Next, the laminated body is pressed with a pressing die. Specifically, a 70 μm thick, 5×10 elastic modulus SiO2 film is placed between the laminate and a pressing die plate, that is, on the top surface of the current collector of the laminate. 6An elastic sheet having a pressure of about 300 MPa is inserted. With this configuration, pressure is applied to the laminate via the elastic sheet. Thereafter, the laminate is pressurized for 90 seconds while the pressurizing die is heated to 50° C. at a pressure of 300 MPa. This results in a unit cell 408a before chamfering. Also, a unit cell 408b before chamfering is produced in a similar manner.

[0169] Thereafter, the four corners of the electrode layer 100 of the unit cell 408a and the four corners of the counter electrode layer 200 of the unit cell 408b are cut using a cutter to be chamfered. Then, the cut surfaces are polished with abrasive paper of #800. As a result, a chamfered portion 800 is formed on the electrode layer 100 of the unit cell 408a, and a chamfered portion 801 is formed on the counter electrode layer 200 of the unit cell 408b. In addition, in the chamfering, the four corners of the electrode layer 100 and the counter electrode layer 200 may be polished using abrasive paper instead of cutting with a cutter to form the chamfered portion 800 and the chamfered portion 801. Thereafter, polishing waste from the current collector and the active material layer is wiped off with a nonwoven fabric and washed.

[0170] Thereafter, as the material of the insulating member 900 and the insulating member 901, a thermosetting epoxy resin is applied to the chamfered portion 800 and the chamfered portion 801 in a thickness of about 10 μm to 30 μm, and after being thermally cured at about 100° C. to 200° C., it is cooled to room temperature at a rate of about 50° C. / min or less. By cooling at a cooling rate of 50° C. / min or less, the insulating member is unlikely to peel off. As a result, the insulating member 900 covers and adheres to the chamfered portion 800, and the insulating member 901 covers and adheres to the chamfered portion 801. At this time, the application and curing of the material of the insulating member 900 and the insulating member 901 may be repeated, for example, three times, and an insulating member of about 30 μm to 90 μm may cover and adhere to the chamfered portion 800 and the chamfered portion 801.

[0171] Next, a thermosetting conductive paste containing silver particles is screen-printed to a thickness of about 30 μm on the surface of the counter electrode collector 210 of the unit cell 408a prepared as described above. Then, the unit cell 408b is arranged and compressed so that the counter electrode collector 210 of the unit cell 408a and the electrode collector 110 of the unit cell 408b are joined by the conductive paste. Thereafter, the unit cells 408a and 408b are pressed together under a pressure of, for example, about 1 kg / cm. 2 The battery 1800 is then left to stand with a pressure of 1,000 MPa applied thereto, and then subjected to a heat curing treatment at a temperature of about 100° C. to 300° C. for 60 minutes, after which the battery 1800 is cooled to room temperature.

[0172] Since unit cell 408a has the same configuration as power generating element 500, batteries 1000, 1100, 1200, 1300, 1400, 1500, 1600 and 1700 can be manufactured by forming chamfered portions and insulating members according to the shape of each battery on unit cell 408a before chamfering.

[0173] The method and order of forming the battery are not limited to the above example.

[0174] In the above-mentioned 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 a doctor blade method, a calendar method, a spin coating method, a dip coating method, an inkjet method, an offset method, a die coating method, and a spray method.

[0175] In the above-mentioned manufacturing method, the thermosetting conductive paste containing silver metal particles is shown as an example of the conductive paste, but the conductive paste is not limited thereto. The resin used in the thermosetting conductive paste may be any resin that functions as a binder for bonding, and may be selected appropriately depending on the manufacturing process to be adopted, such as printability and coatability. The resin used in the thermosetting conductive paste may include, for example, a thermosetting resin. Examples of the thermosetting resin include (i) amino resins such as urea resin, melamine resin, and guanamine resin, (ii) epoxy resins such as bisphenol A type, bisphenol F type, phenol novolac type, and alicyclic type, (iii) oxetane resin, (iv) phenol resins such as resol type and novolac type, 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.

[0176] (Other embodiments) Although the battery according to the present disclosure has been described above based on the embodiment and each modified example, the present disclosure is not limited to these embodiment and each modified example. As long as it does not deviate from the gist of the present disclosure, various modifications conceived by a person skilled in the art to the embodiment and other forms constructed by combining some of the components in the embodiment and each modified example are also included in the scope of the present disclosure.

[0177] For example, in the above-described embodiment and each modified example, the solid electrolyte layer is in contact with the lower surface of the electrode active material layer and the upper surface of the counter electrode active material layer, but is not limited thereto. The solid electrolyte layer may be in contact with the side surfaces of the electrode active material layer and the counter electrode active material layer, the lower surface of the electrode current collector, and the upper surface of the counter electrode current collector so as to cover the respective side surfaces of the electrode active material layer and the counter electrode active material layer.

[0178] Also, for example, in the above embodiment and each modified example, the insulating member covers the entire surface of the chamfered portion, but this is not limited thereto. The insulating member may cover only a part of the chamfered portion.

[0179] Furthermore, the above-described embodiment and each modified example can be modified, substituted, added, omitted, and the like in various ways within the scope of the claims or their equivalents. [Industrial Applicability]

[0180] The battery according to the present disclosure can be used, for example, as a secondary battery such as an all-solid-state battery for use in various electronic devices or automobiles. [Explanation of symbols]

[0181] 100 electrode layers 110 Electrode current collector 120 Electrode active material layer 200 Polar Layer 210 Counter electrode current collector 220 Counter electrode active material layer 300 solid electrolyte layer 408a, 408b unit cell 500, 501, 503, 504, 506, 507, 508 Power generation elements 800, 801, 803, 804, 806, 807 Chamfered section 900, 901, 902, 903, 904, 905, 906, 907 Insulating material 905a, 905b Insulating film 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800 batteries

Claims

1. a power generating element including a first electrode layer, a second electrode layer, and a solid electrolyte layer located between the first electrode layer and the second electrode layer; An insulating member; Equipped with At least a part of the corners of the power generating element is provided with a chamfered portion, the insulating member covers at least a portion of the chamfered portion, The chamfered portion is inclined with respect to the stacking direction of the power generating element. battery.

2. A power generating element including a first electrode layer, a second electrode layer, and a solid electrolyte layer located between the first electrode layer and the second electrode layer; An insulating member; Equipped with At least a part of the corners of the power generating element is provided with a chamfered portion, the insulating member covers at least a portion of the chamfered portion, The insulating member includes a structure in which a plurality of insulating films are stacked. battery.

3. The types of materials contained in the insulating films are different from each other.

3. The battery of claim 2.

4. The hardness of the insulating films is lower in the insulating films closer to the chamfered portion. The battery according to claim 2 or 3.

5. The shape of the power generating element is a rectangular parallelepiped. The battery of any one of claims 1 to 4.

6. The chamfered portions are located at four corners of the rectangular parallelepiped in a plan view of the power generating element.

6. The battery of claim 5.

7. The chamfered portion is a curved surface. The battery of any one of claims 1 to 6.

8. The first electrode layer is A current collector; an active material layer located between the current collector and the solid electrolyte layer, the chamfered portion is provided across the current collector and the active material layer, the insulating member covers the current collector and the active material layer at the chamfered portion; The battery of any one of claims 1 to 7.

9. the chamfered portion is provided across the current collector, the active material layer, and the solid electrolyte layer, the insulating member covers the current collector, the active material layer, and the solid electrolyte layer at the chamfered portion; 9. The battery of claim 8.

10. The insulating member covers the outer periphery of the chamfered portion.

10. The battery of claim 1.

11. the insulating member is softer than the first electrode layer, the solid electrolyte layer, and the second electrode layer; The battery of any one of claims 1 to 10.

12. The insulating member includes a resin. The battery of any one of claims 1 to 11.

13. the power generating element includes a structure in which a plurality of unit cells, each of which includes the first electrode layer, the solid electrolyte layer, and the second electrode layer, are stacked.

13. The battery of claim 1.

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

14. The battery of claim 1.

15. a power generating element including a first electrode layer, a second electrode layer, and a solid electrolyte layer located between the first electrode layer and the second electrode layer; An insulating member; A method for manufacturing a battery comprising: providing a chamfered portion inclined with respect to a stacking direction of the power generating element on at least a part of a corner of the power generating element; covering at least a portion of the chamfered portion with the insulating member; Including, How batteries are manufactured.

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