Battery

Abstract

A battery according to the present disclosure comprises a battery cell stack and a housing that accommodates the battery cell stack. The surface of the battery cell stack includes a first main surface, a second main surface, and a side surface horizontal to a first direction that is a stacking direction. The housing includes: a first housing part having a first plate-shaped part facing the first main surface and a first side wall portion facing the side surface; and a second housing part having a second plate-shaped part facing the second main surface and a second side wall portion facing the side surface. The first side wall portion includes a first convex region, the second side wall portion includes a second convex region, the first side wall portion and the second side wall portion do not overlap each other when viewed from a second direction that is a direction perpendicular to the side surface, and the first convex region and the second convex region at least partially overlap each other when viewed from a third direction that is a direction perpendicular to the first direction and along the side surface.

Description

[Technical field]

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

[0002] Batteries such as lithium ion secondary batteries are used as in-vehicle batteries, which are required to have high capacity, safety, and light weight.

[0003] Conventional batteries using organic electrolytes, such as lithium ion secondary batteries, have the risk of fire, explosion, and ignition due to leakage, etc. For this reason, all-solid-state secondary batteries (hereinafter referred to as all-solid-state batteries), which use solid electrolytes instead of organic electrolytes, have been attracting attention.

[0004] Conventional automotive batteries have mainly been housed in a metal can exterior using a metal plate. However, to reduce weight and size, research is underway into the use of laminate film exteriors made of metal foil and resin.

[0005] Patent Document 1 discloses an all-solid-state battery that houses an electrode body (cell laminate), which is a power generating element, inside an exterior body made of a laminate film.

[0006] Patent Document 2 discloses a battery that contains an all-solid-state battery laminate, which is a power generating element, and is contained in a laminate film so as to cover a pair of housings having side walls extending toward each other in the thickness direction of the all-solid-state battery laminate. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 5648747 [Patent Document 2] JP 2019-57436 A Summary of the Invention [Problem to be solved by the invention]

[0008] There is a need in the art for a highly reliable battery. Accordingly, the present disclosure provides a battery with improved reliability. [Means for solving the problem]

[0009] A battery according to one aspect of the present disclosure includes a power generating element including a structure in which a positive electrode, an electrolyte, and a negative electrode are stacked, and a housing that houses the power generating element, wherein a surface of the power generating element includes a first main surface that is a plane perpendicular to a first direction that is a stacking direction in the power generating element, a second main surface that is a surface opposite to the first main surface, and a side surface that is a plane parallel to the first direction, and the housing includes a first housing portion having a first plate-shaped portion facing the first main surface and a first side wall portion extending from an end of the first plate-shaped portion towards the power generating element and facing the side surface, a second plate-shaped portion facing the second main surface, and a second plate-shaped portion extending from an end of the second plate-shaped portion towards the power generating element and facing the side surface. and a second housing portion having a second side wall portion extending toward the power generating element side of the second plate-shaped portion and facing the side surface, wherein the first side wall portion includes at least one first convex region that is convex in the direction in which the first side wall portion extends, and the second side wall portion includes at least one second convex region that is convex in the direction in which the second side wall portion extends, wherein the first side wall portion and the second side wall portion do not overlap when viewed from a second direction that is perpendicular to the side surface, and the at least one first convex region and the at least one second convex region at least partially overlap when viewed from a third direction that is perpendicular to the first direction and along the side surface. Effect of the Invention

[0010] According to the present disclosure, the reliability of the battery can be improved. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of a battery according to a comparative example. [Diagram 2] FIG. 2 is a perspective view showing a schematic configuration of a battery according to an embodiment. [Diagram 3]FIG. 3 is a top view showing a schematic configuration of a battery according to an embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 5 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is a cross-sectional view showing a schematic configuration of a casing of a battery according to a first modification of the embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a schematic configuration of a casing of a battery according to a second modification of the embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a schematic configuration of a casing of a battery according to a third modification of the embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a schematic configuration of a casing of a battery according to a fourth modification of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (Findings that have led to one aspect of the present disclosure) The present inventors have found that when the reliability of a battery, particularly an all-solid-state battery, is increased by protecting it with a case or the like, the following problems arise.

[0013] In the configuration described in Patent Document 1 mentioned above, an exterior body made of a film material is used, which means that the electrode body inside the exterior body is not sufficiently protected, and there is a problem that the electrode body may be damaged or peeled off due to external forces such as impact and vibration.

[0014] In the configuration described in the above-mentioned Patent Document 2, there is a problem that stress is concentrated on the laminate film at the end of the side wall of the housing, causing a decrease in the mechanical strength of the laminate film, resulting in the laminate film being torn or having defects. Furthermore, there is also a problem that the side walls of the pair of housings overlap in a direction toward the outside of the all-solid-state battery stack, increasing the volume that does not contribute to the power generation capacity, thereby decreasing the volumetric energy density.

[0015] The problems in Patent Document 2 will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing a schematic configuration of a battery 900 according to a comparative example of the present disclosure. The battery 900 according to the comparative example includes an all-solid-state battery laminate 920 (i.e., a power generating element) including a stack of multiple all-solid-state battery cells, an upper housing part 930 and a lower housing part 940 disposed on the upper and lower surfaces of the all-solid-state battery laminate 920, and a flexible exterior body 950 covering the upper housing part 930 and the lower housing part 940.

[0016] When the sealed space in the flexible exterior body 950 is depressurized, the upper housing part 930 and the lower housing part 940 are uniformly pressurized by atmospheric pressure. At this time, the flexible exterior body 950 is in close contact with the end part 900C of the upper housing part 930, and the stress from the upper housing part 930 to the flexible exterior body 950 is concentrated on the end part 900C. Therefore, there is a risk that the flexible exterior body 950 will break or become defective at the point where the end part 900C and the flexible exterior body 950 contact each other. This reduces the reliability of the battery 900.

[0017] Furthermore, the side walls of the upper housing part 930 and the lower housing part 940 overlap in a direction toward the outside of the all-solid-state battery stack, generating a space 900S that does not contribute to the power generation capacity, thereby reducing the volumetric energy density of the battery 900. Thus, in the battery 900, the effect of increasing reliability provided by the housing and the flexible exterior body 950 is insufficient, and the volumetric energy density is also reduced.

[0018] In view of the above problems, the present disclosure provides a battery having improved reliability and energy density by covering the power generating element of the battery with a case and suppressing a decrease in the volumetric energy density of the battery. In addition, when the case is covered with an exterior body such as a laminate film, the battery has further improved reliability by suppressing the occurrence of breakage or defects in the exterior body.

[0019] An outline of one aspect of the present disclosure is as follows.

[0020] A battery according to one aspect of the present disclosure includes a power generating element including a structure in which a positive electrode, an electrolyte, and a negative electrode are stacked, and a housing that houses the power generating element, wherein a surface of the power generating element includes a first main surface that is a plane perpendicular to a first direction that is a stacking direction in the power generating element, a second main surface that is a surface opposite to the first main surface, and a side surface that is a plane parallel to the first direction, and the housing includes a first housing portion having a first plate-shaped portion facing the first main surface and a first side wall portion extending from an end of the first plate-shaped portion towards the power generating element and facing the side surface, a second plate-shaped portion facing the second main surface, and a second plate-shaped portion extending from an end of the second plate-shaped portion towards the power generating element and facing the side surface. and a second housing portion having a second side wall portion extending toward the power generating element side of the second plate-shaped portion and facing the side surface, wherein the first side wall portion includes at least one first convex region that is convex in the direction in which the first side wall portion extends, and the second side wall portion includes at least one second convex region that is convex in the direction in which the second side wall portion extends, wherein the first side wall portion and the second side wall portion do not overlap when viewed from a second direction that is perpendicular to the side surface, and the at least one first convex region and the at least one second convex region at least partially overlap when viewed from a third direction that is perpendicular to the first direction and along the side surface.

[0021] As a result, the power generating element is covered by the housing, and the power generating element is protected from external impacts and the like. In addition, the first convex region of the first side wall portion and the second convex region of the second side wall portion overlap at least partially when viewed from the third direction, so that one of the first side wall portion and the second side wall portion is less likely to protrude outward from the power generating element than the other. Therefore, a space that does not contribute to the power generating capacity, which occurs when the first side wall portion or the second side wall portion protrudes outward from the power generating element, is less likely to be formed, and the volumetric energy density of the battery is improved. In addition, since one of the first side wall portion and the second side wall portion is less likely to protrude outward from the power generating element than the other, even when the housing is further covered with an exterior body and the exterior body comes into contact with the housing, the stress on the exterior body due to contact between the end of the first side wall portion and the end of the second side wall portion and the exterior body can be reduced. As a result, the occurrence of breakage or defects in the exterior body is suppressed. Therefore, in the battery according to this embodiment, the reliability can be improved and the energy density can be increased.

[0022] Also, for example, a surface of the first side wall portion opposite to the side surface and a surface of the second side wall portion opposite to the side surface may be flush with each other.

[0023] As a result, there is no step between the surface opposite the side surface of the first side wall and the surface opposite the side surface of the second side wall. Therefore, no space that does not contribute to the power generation capacity is formed due to the step, and the volumetric energy density of the battery can be further improved. In addition, the structure is such that one of the first side wall and the second side wall does not protrude further outward from the power generation element than the other. Therefore, even if the housing is further covered with an exterior body and the exterior body comes into contact with the housing, the ends of the first side wall and the second side wall, where stress is likely to concentrate, are less likely to come into contact with the exterior body, and the occurrence of breakage or defects in the exterior body is further suppressed.

[0024] Furthermore, for example, of the at least one first convex region and the at least one second convex region, a first convex region and a second convex region adjacent to each other in the third direction may be in contact with each other.

[0025] As a result, when an external impact is applied in the third direction, the first convex region and the second convex region adjacent to each other in the third direction act as stoppers to prevent the first housing part and the second housing part from shifting in the third direction, thereby preventing damage to the power generating element.

[0026] Furthermore, for example, of the at least one first convex region and the at least one second convex region, a gap may exist between a first convex region and a second convex region that are adjacent to each other in the third direction.

[0027] This suppresses dust generation caused by scraping of the housing material due to friction between the first convex region and the second convex region, etc. This reduces the possibility of the housing material adhering to the power generating element and causing performance degradation or a short circuit, etc., thereby improving the reliability of the battery.

[0028] Furthermore, for example, when viewed from the second direction, a gap may exist between the at least one first convex region and the second plate-shaped portion, and between the at least one second convex region and the first plate-shaped portion.

[0029] As a result, when pressure is applied by covering the battery cell with an exterior body and reducing the pressure of the sealed space inside the exterior body, the pressure is applied to the battery cell stack via the first and second housing parts, and the power generating element is compressed in the stacking direction. As a result, if particles such as a solid electrolyte are present in the power generating element, the relatively soft solid electrolyte is deformed, and the particles move to fill the gaps, thereby reducing the gaps between the particles of the material present inside the power generating element. This increases the density of the power generating element, improving the volumetric energy density, while reducing the resistance between the particles and improving the battery characteristics.

[0030] Also, for example, the at least one first convex region may include a plurality of first convex regions aligned along the third direction, and the at least one second convex region may include a plurality of second convex regions aligned along the third direction.

[0031] As a result, the side surfaces of the power generating element are covered by the multiple first convex regions and the multiple second convex regions, thereby enhancing the effect of protecting the side surfaces of the power generating element.

[0032] Furthermore, for example, the first convex regions and the second convex regions of each of the plurality of first convex regions and the plurality of second convex regions may be arranged alternately along the third direction.

[0033] This results in a structure in which the first convex region and the second convex region interlock, thereby preventing the first housing part and the second housing part from shifting in the third direction in the event of an impact from the third direction.

[0034] Furthermore, for example, at least one of the length in the third direction of each of the plurality of first convex regions and the length in the third direction of each of the plurality of second convex regions may not be uniform.

[0035] As a result, for example, in the multiple first convex regions, there are first convex regions with a large length in the third direction and first convex regions with a small length in the third direction. The first convex regions with a large length in the third direction are likely to come into contact with the second convex regions adjacent thereto in the third direction, and the first housing part and the second housing part are prevented from being displaced in the third direction in response to an impact from the third direction. On the other hand, the first convex regions with a small length in the third direction are unlikely to come into contact with the second convex regions adjacent thereto in the third direction. Therefore, dust generation caused by the material of the housing being scraped off due to friction between the first convex region and the second convex region is prevented. Therefore, both the prevention of the displacement in the third direction between the first housing part and the second housing part and the prevention of dust generation are achieved. The same is true in the case where the multiple second convex regions have second convex regions with different lengths in the third direction.

[0036] Also, for example, at least one of the length in the first direction of each of the plurality of first convex regions and the length in the first direction of each of the plurality of second convex regions may not be uniform.

[0037] As a result, for example, in the multiple first convex regions, there are first convex regions with a large length in the first direction and first convex regions with a small length in the first direction. Therefore, when the housing is compressed from both sides in the first direction, the first convex region with a large length in the first direction comes into contact with the second housing part (for example, the second plate-shaped part of the second housing part) and functions as a stopper, so that the power generating element is prevented from being compressed beyond a certain level. On the other hand, the first convex region with a small length in the first direction is unlikely to come into contact with the second housing part. Therefore, dust generation caused by the material of the housing being scraped off due to friction between the second housing part and the first convex region, etc. is prevented. The same applies when multiple second convex regions have second convex regions with different lengths in the first direction.

[0038] Also, for example, the length of the first side wall portion in the second direction may be different from the length of the second side wall portion in the second direction.

[0039] As a result, one of the first side wall portion and the second side wall portion has a small thickness, so that the battery can be made lighter and the weight energy density of the battery can be improved.

[0040] Also, for example, the battery may further include an exterior body that covers the casing.

[0041] This allows the power generating element to be covered by the exterior body from the outside of the casing, thereby protecting the power generating element from moisture, air, etc. This further increases the reliability of the battery.

[0042] For example, the exterior body may be flexible.

[0043] This allows the housing to more easily conform to the outer surface shape, improving the sealing performance of the exterior body.

[0044] Also, for example, the exterior body may be made of a laminate film.

[0045] As a result, the exterior body has a layered structure of a metal layer and a resin layer, and therefore the power generating element is protected by the exterior body, which has high flexibility due to the resin layer and high barrier properties against air and water due to the metal layer.

[0046] For example, the electrolyte may include a solid electrolyte having lithium ion conductivity.

[0047] This makes it possible to improve the reliability and energy density of a lithium ion battery containing a solid electrolyte.

[0048] Hereinafter, the embodiment will be described in detail with reference to the drawings.

[0049] 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.

[0050] Furthermore, in this specification, terms indicating the relationship between elements, such as "parallel," terms indicating the shape of elements, such as "flat" and "rectangle," 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.

[0051] 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.

[0052] In the present specification and drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional Cartesian coordinate system. In each embodiment, the z-axis direction is the stacking direction of each layer of the power generating element. The positive direction of the z-axis is the upper side in the z-axis direction, and the negative direction of the z-axis is the lower side in the z-axis direction.

[0053] In addition, in this specification, the terms "above" and "below" in the configuration of a battery and a stacked battery do not refer to the upward direction (vertically upward) and downward 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 stacked configuration. In addition, the terms "above" and "below" are applied not only to the case where two components are arranged with a gap between them and another component is present between the two components, but also to the case where two components are arranged closely together and are in contact with each other.

[0054] (Embodiment) [composition] First, a schematic configuration of a battery according to an embodiment will be described. Fig. 2 is a perspective view showing a schematic configuration of a battery 1 according to the present embodiment. In Fig. 2, an exterior body 50, which will be described later, is omitted in order to show the structure of a housing 20.

[0055] As shown in Fig. 2, the battery 1 according to the present embodiment includes a battery cell stack 10 including a battery cell 10a, and a housing 20 that houses the battery cell stack 10. In this specification, the battery cell 10a is an example of a structure, and the battery cell stack 10 is an example of a power generating element. Although not shown in Fig. 2, the battery 1 may further include an exterior body 50 that covers the housing 20. The battery 1 is, for example, an all-solid-state battery.

[0056] The battery cell 10a has a structure in which a positive electrode, an electrolyte, and a negative electrode are laminated in this order. The electrolyte is, for example, a solid electrolyte layer. The positive electrode is, for example, a positive electrode collector and a positive electrode active material layer located between the positive electrode collector and the solid electrolyte layer. The negative electrode is, for example, a negative electrode collector and a negative electrode active material layer located between the negative electrode collector and the solid electrolyte layer. That is, the battery cell 10a may have a structure in which a positive electrode collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode collector are laminated in this order. The plurality of battery cells 10a may have a structure in which adjacent battery cells 10a share a positive electrode collector or a negative electrode collector. In the plurality of battery cells 10a, the side surface of each layer may be covered with a sealing member made of a sealing resin or the like.

[0057] 2, the multiple battery cells 10a are stacked so as to be electrically connected in parallel. The multiple battery cells 10a may be stacked in any manner so long as they function as a battery, and may be stacked, for example, so as to be electrically connected in series.

[0058] The battery cell stack 10 has a structure in which multiple battery cells 10a are stacked in the z-axis direction. The battery cell stack 10 does not need to include multiple battery cells 10a, and the battery cell stack 10 may be composed of a single battery cell 10a. In the battery cell stack 10, terminals 16 and 17 that are electrically connected to the positive electrode current collector or the negative electrode current collector of the battery cell 10a are drawn out from the side surfaces.

[0059] The positive electrode current collector and the negative electrode current collector may be made of any known material, such as a foil, plate, or mesh made of copper, aluminum, nickel, iron, stainless steel, platinum, gold, or an alloy of two or more of these metals.

[0060] The positive electrode active material layer contains at least a positive electrode active material, and may contain at least one of a solid electrolyte, a conductive assistant, and a binding agent (binder) as necessary.

[0061] As the positive electrode active material, a known material capable of absorbing and releasing (inserting and desorbing, or dissolving and depositing) lithium ions, sodium ions, or magnesium ions can be used. As the positive electrode active material, in the case of a material capable of extracting and inserting lithium ions, for example, lithium cobalt oxide composite oxide (LCO), lithium nickel oxide composite oxide (LNO), lithium manganese oxide composite oxide (LMO), lithium-manganese-nickel composite oxide (LMNO), lithium-manganese-cobalt composite oxide (LMCO), lithium-nickel-cobalt composite oxide (LNCO), or lithium-nickel-manganese-cobalt composite oxide (LNMCO) can be used.

[0062] As the solid electrolyte, known materials such as lithium ion conductors, sodium ion conductors, or magnesium ion conductors can be used. As the solid electrolyte, both inorganic solid electrolytes and polymer solid electrolytes (including gel-like solid electrolytes) can be used. As the inorganic solid electrolyte, for example, a sulfide solid electrolyte or an oxide solid electrolyte is used. As the sulfide solid electrolyte, in the case of a material capable of conducting lithium ions, for example, a composite of lithium sulfide (Li2S) and diphosphorus pentasulfide (P2S5) is used. As the sulfide solid electrolyte, sulfides such as Li2S-SiS2, Li2S-B2S3, or Li2S-GeS2 may be used, and sulfides obtained by adding at least one of Li3N, LiCl, LiBr, Li3PO4, and Li4SiO4 as an additive to the above sulfides may be used.

[0063] As an oxide solid electrolyte, materials that can conduct lithium ions include, for example, Li7La3Zr2O 12 (LLZ), Li 1.3 Al 0.3 Ti 1.7 (PO4)3(LATP) or (La,Li)TiO3(LLTO) are used.

[0064] The conductive assistant may be, for example, a conductive material such as acetylene black, carbon black, graphite, or carbon fiber, etc. The binder may be, for example, a bonding binder such as polyvinylidene fluoride.

[0065] The negative electrode active material layer contains at least a negative electrode active material, and may contain at least one of a solid electrolyte, a conductive assistant, and a binder, as necessary, similar to the positive electrode active material layer.

[0066] As the negative electrode active material, a known material capable of occluding and releasing (inserting and desorbing, or dissolving and precipitating) lithium ions, sodium ions, or magnesium ions can be used. As the negative electrode active material, in the case of a material capable of extracting and inserting lithium ions, for example, a carbon material such as natural graphite, artificial graphite, graphite carbon fiber, or resin-baked carbon, metallic lithium, a lithium alloy, or an oxide of lithium and a transition metal element can be used.

[0067] The solid electrolyte layer includes at least a solid electrolyte, and may include a binder as necessary. The solid electrolyte layer may include a solid electrolyte having lithium ion conductivity.

[0068] As the solid electrolyte and the binder, the above-mentioned solid electrolyte and binder can be used.

[0069] The housing 20 is a housing for covering the surface of the battery cell stack 10 and protecting the battery cell stack 10 from external impacts and the like. The housing 20 has a first housing section 30 and a second housing section 40. The battery 1 may have a cushioning material between the battery cell stack 10 and at least one of the first housing section 30 and the second housing section 40 for absorbing impacts. The corners of the housing 20 may be chamfered, that is, the housing 20 may have a structure in which the corners are cut. The battery cell stack 10 may be joined to the first housing section 30 and the second housing section 40 by an adhesive, solder, or the like. The first housing section 30 and the second housing section 40 may be joined to each other by an adhesive, solder, or the like.

[0070] The material of the housing 20 is, for example, a conductive material such as metal, or an insulating material such as ceramic or resin. From the viewpoint of ease of processing into a shape, the material of the housing 20 may be a conductive material such as metal. When the material of the housing 20 is a conductive material such as metal, the housing 20 and the battery cell stack 10 are electrically insulated from each other by isolating them with an insulating member, or by covering the housing 20 or the battery cell stack 10 with an insulating layer, for example.

[0071] Next, the details of each component of the battery 1 according to this embodiment will be described with reference to Figs. 3 to 5. Fig. 3 is a top view showing a schematic configuration of the battery 1 according to this embodiment. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3. Fig. 5 is a cross-sectional view taken along line VV in Fig. 3. Note that Fig. 5 shows only the structure of the housing 20 out of the cross-sectional structure taken along line VV in Fig. 3. In other words, the battery cell stack 10 and the exterior body 50 are omitted from Fig. 5.

[0072] The battery cell stack 10 has, for example, a rectangular parallelepiped or cubic shape. The surfaces of the battery cell stack 10 include a first main surface 11 which is a plane perpendicular to a first direction (z-axis direction in this embodiment) which is the stacking direction of the battery cell stack 10, a second main surface 12 which is the surface opposite to the first main surface 11, and a side surface 14 which is a plane parallel to the first direction and connects ends of the first main surface 11 and the second main surface 12.

[0073] The housing 20 has a first housing section 30 that covers the first main surface 11 and a portion of the side surface 14, and a second housing section 40 that covers the second main surface 12 and a portion of the side surface 14. The housing 20 is located between the battery cell stack 10 and the exterior body 50.

[0074] The first housing section 30 has a first plate-shaped section 32 facing the first main surface 11, and a first side wall section 34 extending from an end of the first plate-shaped section 32 toward the battery cell stack 10 of the first plate-shaped section 32 and facing the side surface 14. The second housing section 40 has a second plate-shaped section 42 facing the second main surface 12, and a second side wall section 44 extending from the end of the second plate-shaped section 42 toward the battery cell stack 10 of the second plate-shaped section 42 and facing the side surface 14.

[0075] The first plate-shaped portion 32 has, for example, a rectangular plate shape when viewed from the first direction, and is disposed parallel to the first main surface 11. The first plate-shaped portion 32 completely covers the first main surface 11, and overlaps with the battery cell stack 10 when viewed from the first direction.

[0076] The first side wall portions 34 are plate-shaped side walls that stand perpendicular to the first plate-shaped portion 32, and are disposed parallel to the side surfaces 14. The first side wall portions 34 are provided in four locations so as to face all of the side surfaces 14 of the battery cell stack 10. The first side wall portions 34 and the side surfaces 14 may be separated from each other or in contact with each other.

[0077] The first side wall 34 includes a first convex region 35 that is convex in the direction in which the first side wall 34 extends. The first side wall 34 includes a plurality of first convex regions 35. The number of first convex regions 35 included in the first side wall 34 is not particularly limited, and may be one or may be two or more. The first convex region 35 is a region that is directly connected to the end of the first plate-shaped portion 32. Therefore, the first side wall 34 is composed of a plurality of first convex regions 35. When viewed from a second direction (the x-axis direction in the example shown in FIG. 5) that is a direction perpendicular to the side surface 14 facing the first side wall 34 and the second side wall 44, the first convex region 35 has two sides perpendicular to the first main surface 11 and is rectangular. The length in the first direction from the first plate-shaped portion 32 to the tip of the first convex region 35 is equal to or less than the length in the first direction of the battery cell stack 10.

[0078] The second plate-shaped portion 42 has, for example, a rectangular plate shape when viewed from the first direction, and is disposed parallel to the second main surface 12. The second plate-shaped portion 42 completely covers the second main surface 12, and overlaps with the battery cell stack 10 when viewed from the first direction. Furthermore, the second plate-shaped portion 42 has, for example, the same shape and position as the first plate-shaped portion 32 when viewed from the first direction.

[0079] The second side wall portion 44 is a plate-shaped side wall that stands perpendicular to the second plate-shaped portion 42, and is disposed parallel to the side surface 14. In other words, the first side wall portion 34 and the second side wall portion 44 are configured to extend mutually in the first direction. The second side wall portion 44 is provided in four locations so as to face each of all of the side surfaces 14 of the battery cell stack 10. The second side wall portion 44 and the side surface 14 may be spaced apart or in contact with each other.

[0080] The second side wall 44 includes a second convex region 45 that is convex in the direction in which the second side wall 44 extends. The second side wall 44 includes a plurality of second convex regions 45. The number of second convex regions 45 included in the second side wall 44 is not particularly limited, and may be one or may be two or more. The second convex region 45 is a region that is directly connected to the end of the second plate-shaped portion 42. Therefore, the second side wall 44 is composed of a plurality of second convex regions 45. When viewed from the second direction, the second convex region 45 has two sides perpendicular to the second main surface 12 and is rectangular. The length in the first direction from the second plate-shaped portion 42 to the tip of the second convex region 45 is equal to or less than the length in the first direction of the battery cell stack 10.

[0081] The first side wall portion 34 and the second side wall portion 44 do not overlap when viewed from the second direction. Furthermore, the first convex region 35 and the second convex region 45 at least partially overlap when viewed from a third direction (the y-axis direction in the example shown in FIG. 5 ) that is a direction perpendicular to the first direction and along the side surface 14 facing the first side wall portion 34 and the second side wall portion 44. This allows the side surface 14 of the battery cell stack 10 to be protected by the first side wall portion 34 and the second side wall portion 44. Furthermore, one of the first side wall portion 34 and the second side wall portion 44 is less likely to protrude outward from the battery cell stack 10 than the other. Therefore, when the sealed space in the exterior body 50 is decompressed, the housing 20 is uniformly pressurized by atmospheric pressure through the exterior body 50, and even if the housing 20 and the exterior body 50 come into contact with each other, the stress on the exterior body 50 due to contact between the end of the first side wall portion 34 and the end of the second side wall portion 44 and the exterior body 50 can be reduced. As a result, the occurrence of breakage or defects in the exterior body 50 is suppressed. Thus, the reliability of the battery 1 can be improved. In addition, since the first side wall portion 34 and the second side wall portion 44 overlap when viewed from the second direction, a space that does not contribute to the power generation capacity, which is generated when the first side wall portion 34 or the second side wall portion 44 protrudes toward the outside of the battery cell stack 10 (for example, the above-mentioned space 900S) is unlikely to be formed, and the volumetric energy density of the battery 1 is improved.

[0082] When viewed from the second direction, the total area of ​​the overlapping area between the first side wall portion 34 and the side surface 14 and the area of ​​the overlapping area between the second side wall portion 44 and the side surface 14 may be 25% or more of the area of ​​the side surface 14, may be 40% or more of the area of ​​the side surface 14, or may be 60% or more of the area of ​​the side surface 14. Moreover, when viewed from the second direction, the total area of ​​the overlapping area between the first side wall portion 34 and the side surface 14 and the area of ​​the overlapping area between the second side wall portion 44 and the side surface 14 may be 100% or less of the area of ​​the side surface 14, or may be 80% or less.

[0083] Furthermore, when viewed from the third direction, the second-direction length of the portion where the first convex region 35 and the second convex region 45 overlap may be 50% or more of the shorter of the second-direction length of the first convex region 35 and the second-direction length of the second convex region 45, or may be 75% or more, or may be 100%.

[0084] In addition, the first convex regions 35 and the second convex regions 45 are arranged so as to interlock with each other in a comb-like shape. That is, the first side wall portion 34 and the second side wall portion 44 have a comb-like structure. The first convex regions 35 are arranged at equal intervals along the third direction. The second convex regions 45 are arranged at equal intervals along the third direction, and at the same intervals as the intervals at which the first convex regions 35 are arranged. In addition, one second convex region 45 is positioned so as to be sandwiched between two first convex regions 35, and one first convex region 35 is positioned so as to be sandwiched between two second convex regions 45. Therefore, the first convex regions 35 and the second convex regions 45 are arranged alternately along the third direction. As a result, the first convex region 35 and the second convex region 45 are interlocked, so that the first housing part 30 and the second housing part 40 are prevented from shifting in the third direction in response to an impact from the third direction. Also, the first convex region 35 and the second convex region 45 are alternately arranged, so that an external impact is easily dispersed to the first side wall part 34 and the second side wall part 44.

[0085] In addition, the surface 36 of the first side wall portion 34 opposite the side surface 14 and the surface 46 of the second side wall portion 44 opposite the side surface 14 are flush with each other. In other words, the surfaces 36 and 46 are not stepped and are located on the same flat plane. Here, in this specification, being flush with each other means being substantially flush with each other, and for example, the size of the step between the surfaces 36 and 46 is smaller than the thickness of the exterior body 50. In addition, for example, the size of the step between the surfaces 36 and 46 is 5% or less of the length in the second direction of the shorter of the first side wall portion 34 and the second side wall portion 44. By making the surfaces 36 and 46 flush with each other, a structure is formed in which one of the first side wall portion 34 and the second side wall portion 44 does not protrude further outward from the battery cell stack 10 than the other. As a result, when the sealed space in the exterior body 50 is decompressed, the housing 20 is uniformly pressurized by atmospheric pressure through the exterior body 50, and even if the housing 20 and the exterior body 50 come into contact with each other, the ends of the first side wall portion 34 and the second side wall portion 44, where stress is likely to concentrate, are unlikely to come into contact with the exterior body 50. As a result, defects or tears, etc., of the exterior body 50 originating from the ends of the first side wall portion 34 or the second side wall portion 44 are unlikely to occur. This can improve the reliability of the battery 1. In addition, since there is no step between the surface 36 and the surface 46, no space that does not contribute to the power generation capacity is formed due to the step, and the volumetric energy density of the battery 1 can be further improved. Note that the surface 36 and the surface 46 do not need to be flush with each other as long as the first convex region 35 and the second convex region 45 partially overlap when viewed from the third direction.

[0086] Additionally, the first convex regions 35 and second convex regions 45 adjacent to each other in the third direction are in contact with each other. This prevents the first housing portion 30 and the second housing portion 40 from being displaced in the third direction. This prevents damage to the battery cell stack 10 when an external impact is applied in the third direction. This improves the reliability of the battery 1. In the illustrated example, all of the first convex regions 35 and second convex regions 45 adjacent to each other in the third direction are in contact with each other, but some of the adjacent first convex regions 35 and second convex regions 45 may be in contact with each other.

[0087] The length of each of the first convex region 35 and the second convex region 45 in the first direction is smaller than the length of the battery cell stack 10 in the first direction. That is, in the battery 1, the length of the battery cell stack 10 in the first direction is designed to be larger than the length of each of the first convex region 35 and the second convex region 45 in the first direction. In other words, when viewed from the second direction, a gap 22 exists between the first convex region 35 and the second plate-shaped portion 42, and the end of the first convex region 35 on the second plate-shaped portion 42 side and the second housing portion 40 are not in contact. Also, when viewed from the second direction, a gap 23 exists between the second convex region 45 and the first plate-shaped portion 32, and the end of the second convex region 45 on the first plate-shaped portion 32 side and the first housing portion 30 are not in contact. As a result, when the sealed space in the exterior body 50 is decompressed, a pressure equivalent to atmospheric pressure is applied to the battery cell stack 10 via the first housing portion 30 and the second housing portion 40. In detail, the battery cell stack 10 is compressed from both sides in the first direction by a pressure equivalent to atmospheric pressure via the first plate-shaped portion 32 and the second plate-shaped portion 42. As a result, the solid electrolyte, which is relatively soft among the materials constituting the battery cell stack 10, is deformed, and the gaps between the particles of the material present inside the battery cell stack 10 can be reduced. In addition, the particles move to fill the gaps between the particles of the material present inside the battery cell stack 10. As a result, the density of the battery cell stack 10 increases, the volumetric energy density improves, and at the same time, the resistance between the particles can be reduced, and the battery characteristics improve. In addition, the end of the first convex region 35 on the second plate-shaped portion 42 side and the second housing portion 40, and the end of the second convex region 45 on the first plate-shaped portion 32 side and the first housing portion 30 are not in contact with each other, so that dust generation caused by the material of the housing 20 being scraped off due to contact between the first housing portion 30 and the second housing portion 40, etc. is suppressed.

[0088] The exterior body 50 is an exterior body that covers the housing 20 and protects the battery cell stack 10 from moisture, air, and the like. In the illustrated example, a gap exists between the exterior body 50 and the housing 20, but for example, after covering the housing 20, the sealed space of the exterior body 50 is depressurized, so that the exterior body 50 adheres closely to the housing 20. The exterior body 50 may have flexibility from the viewpoint of conformity to the outer surface shape of the housing 20. The exterior body 50 is composed of, for example, a laminate film. The laminate film is a film having a laminate structure of a resin such as a polyethylene resin or a polypropylene resin and a metal such as aluminum, and a known laminate film can be used. The laminate film has, for example, a three-layer structure in which a resin layer, a metal layer, and a resin layer are laminated in this order. The number of layers of the laminate film is not limited to three layers, and a laminate film with a number of layers according to the specification purpose can be used. The exterior body 50 is composed of a laminate film, so that it is an exterior body that is highly flexible and has excellent barrier properties against air and water. The battery 1 does not necessarily have to include the exterior body 50. The battery 1 may also be sealed from the outside of the housing 20 by a sealing member or the like made of a sealing resin or the like, instead of the exterior body 50.

[0089] [Manufacturing method] Next, a method for manufacturing the battery 1 according to the present embodiment will be described. Note that the method for manufacturing the battery 1 described below is just an example, and the method for manufacturing the battery 1 is not limited to the following example.

[0090] First, a battery cell stack 10 in which multiple battery cells 10a are stacked is prepared. The battery cells 10a can be produced by a known method, such as stacking a positive electrode active material, a solid electrolyte, and a negative electrode active material on a current collector by coating or the like. The battery cells 10a are stacked so as to be connected in series or in parallel to form the battery cell stack 10.

[0091] Next, the first housing section 30 and the second housing section 40 of the housing 20 are prepared. For example, the first housing section 30 and the second housing section 40 are formed into the shapes of the first housing section 30 and the second housing section 40 by processing the material of the housing 20 described above using a general processing method such as bending, pressing, or molding.

[0092] Next, as the exterior body 50, for example, an upper laminate film and a lower laminate film having a three-layer structure in which a resin layer, an aluminum layer, and a resin layer are laminated in this order are prepared.

[0093] The second housing portion 40 is placed on the lower laminate film prepared in this manner. Furthermore, the battery cell stack 10 is placed in the space surrounded by the second plate-shaped portion 42 and the second side wall portion 44 of the second housing portion 40. At this time, the second plate-shaped portion 42 and the second main surface 12 of the battery cell stack 10 are placed so that they face each other.

[0094] Next, the first housing part 30 is placed on top of the battery cell stack 10 placed on the second housing part 40. At this time, the first plate-shaped part 32 and the first main surface 11 of the battery cell stack 10 face each other, and the first convex region 35 and the second convex region 45 do not overlap when viewed from the second direction, but overlap when viewed from the third direction. In this way, the battery cell stack 10 is covered by the housing 20.

[0095] Next, the upper laminate film is further placed so as to sandwich and cover the housing 20 with the lower laminate film.

[0096] Then, the outer peripheries of the upper laminate film and the lower laminate film except for some end portions are bonded by thermocompression bonding to form a bag-shaped laminate film.

[0097] The sealed space of the bag-shaped laminate film containing the battery cell stack 10 covered by the housing 20 is depressurized, and in a state where the pressure is sufficiently reduced, the non-bonded portions are thermocompressed, thereby sealing the battery cell stack 10 covered by the housing 20 with the laminate film. By reducing the pressure of the sealed space of the laminate film and pressurizing the battery cell stack 10 to atmospheric pressure, it is possible to reduce the interfacial resistance at the interface within the solid electrolyte contained in the battery cell stack 10 and improve the battery characteristics.

[0098] [Variation 1] The following describes Modification 1 of the embodiment. In the following description of Modification 1 of the embodiment, differences from the embodiment will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0099] The battery according to the first modification of the embodiment includes a housing 120 instead of the housing 20 of the battery 1 according to the embodiment. Fig. 6 is a cross-sectional view showing a schematic configuration of the housing 120 of the battery according to this modification. Fig. 6 shows a cross-section of the housing 120 at the same position as Fig. 5.

[0100] As shown in FIG. 6, the housing 120 includes a first housing portion 30 and a second housing portion 140. The second housing portion 140 has a second plate-shaped portion 42 and a second side wall portion 144 extending from an end of the second plate-shaped portion 42. The second side wall portion 144 includes a plurality of second convex regions 145 that are convex in the direction in which the second side wall portion 144 extends. The length of the second convex region 145 in the third direction is different from the length of the first convex region 35 in the third direction. The length of the second convex region 145 in the third direction is smaller than the length of the first convex region 35 in the third direction.

[0101] The first side wall portion 34 and the second side wall portion 144 do not overlap when viewed from the second direction. Also, the first convex region 35 and the second convex region 145 overlap when viewed from the third direction. This provides the same effects as the battery 1 according to the embodiment.

[0102] The multiple first convex regions 35 and the multiple second convex regions 145 are arranged to interdigitate with each other in a comb-like shape, that is, the first convex regions 35 and the second convex regions 145 are alternately arranged along the third direction.

[0103] Furthermore, in the housing 120, a gap exists between the first convex region 35 and the second convex region 145 adjacent to each other in the third direction. This suppresses dust generation caused by scraping of the material of the housing 120 due to friction between the first convex region 35 and the second convex region 145, etc. This reduces the possibility that the material of the housing 20 will adhere to the battery cell stack 10, causing a performance degradation or a short circuit in the battery cell stack 10, and improves the reliability of the battery. Furthermore, when the housing 120 is made of an insulating material, it is possible to suppress charging due to friction between the first convex region 35 and the second convex region 145, which may affect the battery cell stack 10.

[0104] [Variation 2] The following describes Modification 2 of the embodiment. In the following description of Modification 2 of the embodiment, differences from the embodiment will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0105] The battery according to the second modification of the embodiment includes a housing 220 instead of the housing 20 of the battery 1 according to the embodiment. Fig. 7 is a cross-sectional view showing a schematic configuration of the housing 220 of the battery according to this modification. Fig. 7 shows a cross section of the housing 220 at the same position as Fig. 5.

[0106] 7, the housing 220 includes a first housing portion 30 and a second housing portion 240. The second housing portion 240 has a second plate-shaped portion 42 and a second side wall portion 244 extending from an end portion of the second plate-shaped portion 42. The second side wall portion 244 includes a plurality of second convex regions 245a and 245b that are convex in the direction in which the second side wall portion 244 extends.

[0107] The first side wall 34 and the second side wall 244 do not overlap when viewed from the second direction. The first convex region 35 and the second convex regions 245a and 245b overlap when viewed from the third direction. This provides the same effects as the battery 1 according to the embodiment.

[0108] The multiple first convex regions 35 and the multiple second convex regions 245a and 245b are arranged to interdigitate with each other, i.e., the first convex regions 35 and the second convex regions 245a or 245b are alternately arranged along the third direction.

[0109] In addition, the second convex region 245a and the second convex region 245b have different lengths in the third direction. That is, the lengths of the multiple second convex regions 245a and 245b are not uniform in the third direction. Specifically, the length in the third direction of the second convex region 245b is greater than the length in the third direction of the second convex region 245a. In addition, the gap between the second convex region 245b and the first convex region 35 adjacent to each other in the third direction is smaller than the gap between the second convex region 245a and the first convex region 35 adjacent to each other in the third direction. As a result, the second convex region 245b is more likely to come into contact with the first convex region 35, and thus the misalignment in the third direction between the first housing unit 30 and the second housing unit 240 is suppressed. Furthermore, because the length of the second convex region 245a in the third direction is smaller than the length of the second convex region 245b in the third direction, the second convex region 245a is less likely to come into contact with the first convex region 35. This prevents dust generation caused by the material of the housing 220 being scraped off due to friction between the first convex region 35 and the second convex region 245a, etc. Furthermore, when the housing 220 is made of an insulating material, charging due to friction between the first convex region 35 and the second convex region 245a that would affect the battery cell stack 10 can be prevented.

[0110] In this modified example, the structure in which the lengths in the third direction of the multiple second convex regions 245a and 245b are not uniform has been described, but the lengths in the third direction of the multiple first convex regions may not be uniform. In other words, at least one of the lengths in the third direction of the multiple first convex regions and the lengths in the third direction of the multiple second convex regions may not be uniform. In addition, there may be no gap between the adjacent second convex regions 245b and first convex regions 35, and the adjacent second convex regions 245b and first convex regions 35 may be in contact with each other.

[0111] [Variation 3] The following describes Modification 3 of the embodiment. In the following description of Modification 3 of the embodiment, differences from the embodiment will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0112] The battery according to the third modification of the embodiment includes a housing 320 instead of the housing 20 of the battery 1 according to the embodiment. Fig. 8 is a cross-sectional view showing a schematic configuration of the housing 320 of the battery according to this modification. Fig. 8 shows a cross section of the housing 320 at the same position as Fig. 5.

[0113] 8, the housing 320 includes a first housing portion 30 and a second housing portion 340. The second housing portion 340 has a second plate-shaped portion 42 and a second side wall portion 344 extending from an end portion of the second plate-shaped portion 42. The second side wall portion 344 includes a plurality of second convex regions 345a, 345b, and 345c that are convex in the direction in which the second side wall portion 344 extends.

[0114] The first side wall 34 and the second side wall 344 do not overlap when viewed from the second direction. The first convex region 35 and the second convex regions 345a, 345b, and 345c overlap when viewed from the third direction. This provides the same effects as the battery 1 according to the embodiment.

[0115] The first convex regions 35 and the second convex regions 345a, 345b, and 345c are arranged to interdigitate with each other, i.e., the first convex regions 35 and the second convex regions 345a, 345b, and 345c are alternately arranged along the third direction.

[0116] In addition, the second convex region 345a, the second convex region 345b, and the second convex region 345c have different lengths in the first direction. That is, the lengths of the second convex regions 345a, 345, and 345c are not uniform in the first direction. Specifically, the lengths in the first direction are larger in the order of the second convex region 345a, the second convex region 345c, and the second convex region 345b. In addition, the size of the gap between the second convex region 345b and the first plate-shaped portion 32 when viewed from the second direction is smaller than the size of the gap between each of the second convex regions 345a and 345c and the first plate-shaped portion 32. As a result, when the housing 20 is compressed from both sides in the first direction, the second convex region 345b comes into contact with the first housing part 30 (the first plate-shaped part 32 of the first housing part 30 in this modified example) and functions as a stopper, preventing the battery cell stack 10 from being compressed beyond a certain level. At that time, the second convex regions 345a and 345c are each shorter in length in the first direction than the second convex region 345b, and therefore are less likely to come into contact with the first plate-shaped part 32. Therefore, dust generation caused by the material of the housing 320 being scraped off due to such contact is prevented.

[0117] In this modified example, the structure in which the lengths of the second convex regions 345a, 345b, and 345c in the first direction are not uniform has been described, but the lengths of the first convex regions may not be uniform. In other words, at least one of the lengths of the first direction of the first convex regions and the lengths of the second convex regions in the first direction may not be uniform. In addition, when the second side wall portion 344 includes regions other than the second convex regions 345a, 345b, and 345c, the lengths in the first direction from the second plate-shaped portion 42 to the tips of the second convex regions 345a, 345b, and 345c may not be uniform.

[0118] [Variation 4] The following describes Modification 4 of the embodiment. In the following description of Modification 4 of the embodiment, differences from the embodiment will be mainly described, and descriptions of commonalities will be omitted or simplified.

[0119] The battery according to the fourth modification of the embodiment includes a housing 420 instead of the housing 20 of the battery 1 according to the embodiment. Fig. 9 is a cross-sectional view showing a schematic configuration of the housing 420 of the battery according to this modification. Fig. 9 shows a cross-section of the housing 420 at the same position as in Fig. 4.

[0120] 9, the housing 420 includes a first housing portion 30 and a second housing portion 440. The second housing portion 440 includes a second plate-shaped portion 42 and a second side wall portion 444 extending from an end portion of the second plate-shaped portion 42.

[0121] Although not shown, in the housing 420, similarly to the embodiment and the first to third modified examples of the embodiment, the first side wall 34 and the second side wall 344 do not overlap when viewed from the second direction. Also, the first convex region of the first side wall 34 and the second convex region of the second side wall 444 overlap when viewed from the third direction.

[0122] In addition, in the housing 420, the length in the second direction of the first side wall portion 34 is different from the length in the second direction of the second side wall portion 444. Specifically, the length in the second direction of the first side wall portion 34 is greater than the length in the second direction of the second side wall portion 444. As a result, since one of the first side wall portion 34 and the second side wall portion 444 is thinner, the weight of the battery can be reduced and the weight energy density of the battery can be improved.

[0123] Furthermore, the surface 36 of the first side wall portion 34 opposite the side surface 14 and the surface 446 of the second side wall portion 444 opposite the side surface 14 are flush with each other. In other words, the surfaces 36 and 446 are not stepped and are located on the same flat plane. As a result, even if the length of the first side wall portion 34 in the second direction and the length of the second side wall portion 444 in the second direction are different, contact between the end of the first side wall portion 34 and the end of the second side wall portion 444 and the exterior body 50 is suppressed when the sealed space in the exterior body 50 is depressurized.

[0124] In this modified example, the case where the length in the second direction of the first side wall portion 34 is greater than the length in the second direction of the second side wall portion 444 has been described, but this is not limited thereto. The length in the second direction of the second side wall portion 444 may be greater than the length in the second direction of the first side wall portion 34.

[0125] In the housing 420, the first side wall portion 34 and the second side wall portion 444 are located on both sides of the battery cell stack 10 so as to sandwich the battery cell stack 10 in the x-axis direction. In both the first side wall portion 34 and the second side wall portion 444 on both sides, the length in the second direction of the first side wall portion 34 is greater than the length in the second direction of the second side wall portion 444, but this is not limited to this. In the housing 420, in the first side wall portion 34 and the second side wall portion 444 on either side, the length in the second direction of the first side wall portion 34 may be greater than the length in the second direction of the second side wall portion 444, or the length in the second direction of the second side wall portion 444 may be greater than the length in the second direction of the first side wall portion 34. In addition, in the housing 420, in the first side wall portion 34 and the second side wall portion 444 on either side, the length in the second direction of the first side wall portion 34 and the length in the second direction of the second side wall portion 444 may be the same.

[0126] (Other embodiments) Although the battery according to the present disclosure has been described above based on the embodiments, the present disclosure is not limited to these embodiments. As long as it does not deviate from the gist of the present disclosure, various modifications conceivable by a person skilled in the art to the embodiments and other forms constructed by combining some of the components in the embodiments are also included in the scope of the present disclosure.

[0127] For example, in the above embodiment, the first side wall portion and the second side wall portion are provided at four locations so as to face the four side surfaces of the battery cell stack, but this is not limited to the above. The first side wall portion and the second side wall portion may be provided at one or more locations and three or less locations. For example, the first side wall portion and the second side wall portion may be provided only at locations that are likely to receive external impacts.

[0128] In the above embodiment, the first convex regions are arranged at equal intervals along the third direction, but this is not limited to the above. The pitch at which the first convex regions are arranged along the third direction does not have to be equal, and for example, two second convex regions may be located between adjacent first convex regions.

[0129] In the above embodiment, the first convex region and the second convex region are rectangular when viewed from the second direction, but are not limited thereto. For example, the shape of the first convex region and the second convex region when viewed from the second direction may be a quadrangle other than a rectangle, such as a trapezoid, a triangle, or a polygon, such as a pentagon. The first convex region and the second convex region may have a rounded tip when viewed from the second direction. The rounded tip can suppress dust generation caused by the tip being scraped.

[0130] In the above embodiment, when viewed from the second direction, a gap exists between the first convex region and the second plate-shaped portion, and the end of the first convex region on the second plate-shaped portion side is not in contact with the second housing portion. However, this is not limited to the above. For example, there may be no gap between the first convex region and the second plate-shaped portion, and the end of the first convex region on the second plate-shaped portion side is in contact with the second housing portion. Even if the end of the first convex region on the second plate-shaped portion side is in contact with the second housing portion, the battery cell stack can be pressurized from both sides in the first direction by using a material with an elastic modulus that can be deformed at atmospheric pressure for the housing. The same applies to the gap between the second convex region and the first plate-shaped portion.

[0131] Also, for example, in the above embodiment, the side surface of the battery cell stack may have irregularities due to the sizes of the layers, etc. In this case, the direction connecting the ends of the first main surface and the second main surface that are in an overlapping position when viewed from the first direction may be the direction in which the side surface of the battery cell stack spreads.

[0132] In the above embodiment, the first side wall portion is composed of a plurality of first convex regions, but is not limited thereto. For example, the first side wall portion may have a region that is the same width as the width of the end of the first plate-shaped portion and stands from the end of the first plate-shaped portion, and at least one first convex region may be formed on the opposite side of the region from the first plate-shaped portion. The same applies to the second side wall portion.

[0133] In the above embodiment, the battery cell stack has a rectangular parallelepiped shape, but this is not limiting. For example, the battery cell stack may have a polygonal prism shape or a cylindrical shape.

[0134] Furthermore, the above-described embodiment can be modified, replaced, added, omitted, and the like in various ways within the scope of the claims or their equivalents. [Industrial Applicability]

[0135] The battery according to the present invention can be used in a battery having a housing that protects the battery cell stack from external impacts. [Explanation of symbols]

[0136] 1 battery 10 Battery cell stack 10a battery cell 11 First main surface 12 Second main surface 14 Side 16, 17 Terminals 20, 120, 220, 320, 420 housing 22, 23 void 30 First housing section 32 First plate-shaped portion 34 First side wall 35 1st convex region 36, 46, 446 sides 40, 140, 240, 340, 440 Second housing part 42 Second plate-shaped portion 44, 144, 244, 344, 444 Second side wall 45, 145, 245a, 245b, 345a, 345b, 345c Second convex region 50 Exterior body

Claims

1. a power generating element including a structure in which a positive electrode, an electrolyte, and a negative electrode are stacked; a housing that houses the power generating element; an exterior body that covers the housing; Equipped with The surface of the power generating element is a first main surface that is a plane perpendicular to a first direction that is a stacking direction of the power generating element; a second main surface that is the surface opposite to the first main surface; a side surface that is a plane parallel to the first direction; Including, The housing includes: a first housing portion including a first plate-shaped portion facing the first main surface and a first side wall portion extending from an end of the first plate-shaped portion toward the power generating element side of the first plate-shaped portion and facing the side surface; a second housing portion including a second plate-shaped portion facing the second main surface and a second side wall portion extending from an end of the second plate-shaped portion toward the power generating element side of the second plate-shaped portion and facing the side surface; and the first sidewall portion includes at least one first convex region that is convex in an extension direction of the first sidewall portion, the second side wall portion includes at least one second convex region that is convex in an extension direction of the second side wall portion, the first side wall portion and the second side wall portion do not overlap when viewed from a second direction that is a direction perpendicular to the side surface, the at least one first convex region and the at least one second convex region at least partially overlap each other when viewed from a third direction that is perpendicular to the first direction and along the side surface; battery.

2. a surface of the first side wall portion opposite to the side surface and a surface of the second side wall portion opposite to the side surface are flush with each other; The battery of claim 1 .

3. Among the at least one first convex region and the at least one second convex region, the first convex region and the second convex region adjacent to each other in the third direction are in contact with each other. The battery according to claim 1 or 2.

4. a gap exists between the first convex region and the second convex region adjacent to each other in the third direction, among the at least one first convex region and the at least one second convex region; The battery according to any one of claims 1 to 3.

5. When viewed from the second direction, a gap exists between the at least one first convex region and the second plate-shaped portion, and between the at least one second convex region and the first plate-shaped portion. The battery of any one of claims 1 to 4.

6. the at least one first convex region includes a plurality of first convex regions aligned along the third direction, the at least one second convex region includes a plurality of second convex regions aligned along the third direction; The battery of any one of claims 1 to 5.

7. the first convex regions and the second convex regions of each of the plurality of first convex regions and the plurality of second convex regions are alternately arranged along the third direction; The battery of claim 6.

8. At least one of the lengths of the first convex regions in the third direction and the lengths of the second convex regions in the third direction is not uniform. The battery of claim 7.

9. At least one of the lengths of the first direction of each of the plurality of first convex regions and the lengths of the first direction of each of the plurality of second convex regions is not uniform.

9. The battery of claim 6.

10. a length of the first side wall portion in the second direction is different from a length of the second side wall portion in the second direction; 10. The battery of claim 1.

11. The exterior body is flexible. The battery of any one of claims 1 to 10.

12. The exterior body is made of a laminate film.

12. The battery of claim 1.

13. The electrolyte includes a solid electrolyte having lithium ion conductivity.

13. The battery of any one of claims 1 to 12.

Images