Storage battery, battery module, and laminated film

Abstract

This storage battery comprises a power generation element and an exterior body covering the power generation element. The exterior body is formed by folding a member forming the exterior body into two at a folding portion. The exterior body comprises: a storage portion that stores the power generation element; and an outer edge portion that surrounds the storage portion and includes the folding portion. In the outer edge portion, a first portion between the folding portion and a side of the storage portion is folded along the side that is adjacent to the folding portion.

Description

Storage batteries, battery modules and laminate films

[0001] The present invention relates to a storage battery, a battery module, and a laminate film.

[0002] In order to reduce CO2 emissions from climate-related disasters, the electrification of industrial machinery is being promoted, and research is also being conducted on storage batteries as an energy source for vehicles and other applications. In battery modules composed of such storage batteries, temperature can affect the performance or life of the storage battery, so a device for regulating the temperature of the storage battery is sometimes provided. As an example of a temperature regulation structure, Patent Document 1 describes a cooling structure including a thermally conductive material that is in contact with the storage battery and a cooling plate.

[0003] Japanese Patent Application Laid-Open No. 2015-225765

[0004] In the cooling and heating of the storage battery described above, it is desirable to efficiently transfer heat from the storage battery. However, in cases where a thermally conductive material is provided between the storage battery and the cooling structure as in the above-mentioned conventional technology, the efficiency of cooling and heating may decrease depending on the state of contact between the storage battery and the thermally conductive material.

[0005] The present invention provides a technology for suppressing a decrease in the efficiency of cooling and heating a storage battery.

[0006] According to one aspect of the present invention, there is provided a storage battery comprising: a power generating element; and an exterior body encasing the power generating element; the exterior body is formed by folding a member forming the exterior body in half at a folded portion; the exterior body includes a housing section that houses the power generating element; and a peripheral portion around the housing section including the folded portion; and a first portion of the peripheral portion that is closer to the folded portion than a side surface of the housing section adjacent to the folded portion is folded along the side surface.

[0007] According to the present invention, it is possible to suppress a decrease in the cooling efficiency of the storage battery.

[0008] The accompanying drawings are included in and constitute a part of the specification, illustrate embodiments of the present invention, and are used to explain the principles of the present invention together with the description thereof. A cross-sectional view schematically showing a battery module according to an embodiment. A front view of an all-solid-state battery according to an embodiment. A cross-sectional view taken along line A-A in FIG. 2A. A plan view showing the configuration of a laminate film. A view taken along arrow C in FIG. 3A. A cross-sectional view taken along line B-B in FIG. 2A, showing the structure of the lower part of the all-solid-state battery. A front view of the all-solid-state battery, showing the state before the lower part of the exterior body is folded. A view showing a modified exterior body. A view showing a modified exterior body. A view showing a modified structure of the lower part of the all-solid-state battery.

[0009] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be arbitrarily combined. Furthermore, the same reference numerals are used for the same or similar components, and redundant explanations will be omitted.

[0010] <First embodiment> <Battery module BM> Fig. 1 is a cross-sectional view schematically showing a battery module BM according to one embodiment. The battery module BM is mounted on an electric vehicle such as a hybrid vehicle or an EV (not shown), for example. The battery module BM includes a plurality of all-solid-state batteries 1, a plurality of separators 101, a cooling / heating unit 102, and a plurality of heat transfer members 103.

[0011] A plurality of all-solid-state batteries 1 (battery cells) are stacked in their thickness direction (Z direction) to form a battery group. The all-solid-state batteries 1 are arranged in an upright position and stacked alternately with insulating separators 101 in the Z direction. The configuration of the all-solid-state battery 1 will be described later.

[0012] The cooling and heating unit 102 cools or heats the all-solid-state battery 1. In this embodiment, the cooling and heating unit 102 is a water-cooled heat sink in which a refrigerant passes through fluid passages 102b formed in a plate-shaped member 102a. That is, the cooling and heating unit 102 has a structure for cooling the all-solid-state battery 1. However, the cooling and heating unit 102 may also have a structure for heating the all-solid-state battery 1. Alternatively, the cooling and heating unit 102 may have both a cooling structure and a heating structure for the all-solid-state battery 1. An example of the heating structure is a structure in which an electric heating wire is disposed on the plate-shaped member 102a. Furthermore, as the cooling structure, the cooling and heating unit 102 may employ, for example, an air-cooled cooling and heating structure that introduces wind generated when the vehicle is traveling, or other known techniques may be used as appropriate.

[0013] The heat transfer member 103 transfers heat from the all-solid-state battery 1 to the cooling / heating unit 102. The heat transfer member 103 is disposed between the all-solid-state battery 1 and the cooling / heating unit 102. A thermally conductive gel such as silicone gel may be used as the heat transfer member 103. Alternatively, for example, a urethane-based, epoxy-based, modified silane-based, or acrylic-based heat dissipation adhesive may be used as the heat transfer member 103. Alternatively, for example, a clay-like silicone putty sheet for heat dissipation that adheres well to uneven surfaces, or silicone grease for heat dissipation may be used as the heat transfer member 103. Note that, in this embodiment, a plurality of heat transfer members 103 are provided corresponding to a plurality of all-solid-state batteries 1, respectively, but the heat transfer member 103 may be provided across a plurality of all-solid-state batteries 1.

[0014] Approximately flat end plates 104 are arranged on both ends in the stacking direction of the stack of all-solid-state batteries 1 and separators 101. The end plates 104 are formed with holes through which fastening bolts 105a for fixing the battery module BM to an installation site 201 can pass. The installation site 201 is made of, for example, sheet metal for an electric vehicle, and is formed with a pair of female threaded portions 201a into which the pair of fastening bolts 105a are threaded.

[0015] <All-Solid-State Battery> Figure 2A is a front view of an all-solid-state battery 1 according to one embodiment of the present invention, and Figure 2B is a cross-sectional view taken along line A-A in Figure 2A. In the figure, arrow X indicates the longitudinal direction of the all-solid-state battery 1 (or the direction in which the lead tabs extend), arrow Y indicates the width direction of the all-solid-state battery 1 (or the direction perpendicular to the direction in which the lead tabs extend), and arrow Z indicates the thickness direction of the all-solid-state battery 1 (the stacking direction of the laminate 2), with the X direction, Y direction, and Z direction being perpendicular to one another. Figure 2A is a view of the all-solid-state battery 1 viewed in the Z direction.

[0016] The all-solid-state battery 1 includes a laminate 2 which is an electricity storage element, lead tabs 3 and 4, current collecting tabs 5 and 6, and an exterior body 8 which encases the laminate 2, and has the form of a battery cell suitable for an assembled battery.

[0017] The laminate 2 has a rectangular parallelepiped shape as a whole and has a two-layer structure of positive electrode layers 21A and 21B and two negative electrode layers 24A and 24B. However, the positive electrode layer and the negative electrode layer of the laminate 2 may be one layer or three or more layers. A solid electrolyte layer 27 is provided between the positive electrode layer 21A and the negative electrode layer 24A, and between the positive electrode layer 21B and the negative electrode layer 24B.

[0018] The positive electrode layers 21A and 21B each include a positive electrode active material layer 22, and the two positive electrode layers 21A and 21B share a positive electrode current collector 23. The positive electrode current collector 23 is arranged in a layered form in the center of the stack 2 in the Z direction, and the positive electrode active material layers 22 are stacked on the front and back sides of the positive electrode current collector 23.

[0019] The negative electrode layers 24A and 24B are disposed on one side of the positive electrode layers 21A and 21B in the Z direction, and are stacked such that the positive electrode layers 21A and 21B are sandwiched between the negative electrode layers 24A and 24B. However, a configuration opposite to the configuration of this embodiment, in which two positive electrode layers sandwich two negative electrode layers, may also be employed. The negative electrode layers 24A and 24B each include a negative electrode active material layer 25 and a negative electrode current collector 26. The two negative electrode current collectors 26 are each formed in a layered form on the outermost layers of the laminate 2.

[0020] Examples of active materials constituting the positive electrode active material layer 22 include lithium cobalt oxide, lithium nickel oxide, lithium manganate, lithium metal phosphate, lithium nickel-cobalt manganate, and lithium nickel-cobalt aluminate. Examples of active materials constituting the negative electrode active material layer 25 include lithium-based materials and silicon-based materials. Examples of lithium-based materials include Li metal and Li alloys. Examples of silicon-based materials include Si and SiO. Other examples of active materials constituting the negative electrode active material layer 25 include carbon materials such as graphite, soft carbon, and hard carbon, tin-based materials (Sn, SnO, etc.), and lithium titanate.

[0021] The solid electrolyte layer 27 is made of, for example, a solid electrolyte having ion conductivity, and examples of such materials include a sulfide-based solid electrolyte material, an oxide-based solid electrolyte material, a nitride-based solid electrolyte material, and a halide-based solid electrolyte material. The positive electrode current collector 23 and the negative electrode current collector 26 are made of, for example, a metal foil, a metal sheet, or a metal plate made of aluminum, copper, SUS, or the like. The positive electrode active material layer 22, the negative electrode active material layer 25, and the solid electrolyte layer 27 may be formed by binding particles of the materials that make them up with an organic polymer compound binder.

[0022] The lead tabs 3 and 4 are connected to a charger or an electrical load to charge or discharge the laminate 2. One end of the lead tabs 3 and 4 is located outside the exterior body 8, and the other end is located inside the exterior body 8. Here, the inside of the exterior body 8 refers to the space formed by a housing portion 81 of the exterior body 8, which will be described later.

[0023] The other end of the lead tab 3 is connected to the positive electrode current collector 23 inside the exterior housing 8 via a current collecting tab 5, and the lead tab 3 forms a tab for the positive electrode. The lead tab 3 and the current collecting tab 5 are formed, for example, from a conductive metal sheet or metal plate. Meanwhile, the other end of the lead tab 4 is connected to the negative electrode current collector 26 inside the exterior housing 8 via a current collecting tab 6, and the lead tab 4 forms a tab for the negative electrode. The lead tab 4 and the current collecting tab 6 are formed, for example, from a conductive metal sheet or metal plate.

[0024] The exterior body 8 wraps the laminate 2. In this embodiment, the exterior body 8 is formed by folding a laminate film 301 that forms the exterior body 8 in half. Here, FIG. 3A is a plan view showing the configuration of the laminate film 301, and FIG. 3B is a view taken from the arrow C in FIG. 3A. The laminate film 301 is formed, for example, by covering the front and back surfaces of a metal layer with a resin layer (insulating layer). The exterior body 8 formed by this laminate film 301 has flexibility that can follow the expansion and contraction of the laminate 2. The flexibility that can follow the expansion and contraction of the laminate 2 can be obtained by the way the laminate 2 is wrapped, the shape and structure of the exterior body 8, etc.

[0025] In this embodiment, the exterior body 8 has a rectangular shape with four sides 8a to 8d when viewed in the Z direction. When viewed in the Z direction, the exterior body 8 includes a housing section 81 that houses the stack 2 and a peripheral section 82 around the housing section 81. Note that, although the housing section 81 is disposed in the center of the exterior body 8 when viewed in the Z direction, it may be disposed offset to the left and right and / or top and bottom.

[0026] The storage section 81 is formed by overlapping recesses 311 and 321 formed in portions 310 and 320 on both sides of the folded-back section 301a when the laminate film 301 is in an open state. The storage section 81 includes main surfaces 81e and 81f that extend in a plane (XY plane) intersecting the stacking direction (Z direction) of the laminate 2 and face each other, and side surfaces 81a to 81d that are arranged to connect the main surfaces 81e and 81f.

[0027] The peripheral edge portion 82 is formed by overlapping the portions of the laminate film 301 that do not have the recesses 311 and 321 when the laminate film 301 is in an open state. In this embodiment, the side 8a, one of the four outer sides of the peripheral edge portion 82, includes a folded portion 82a that is folded back when the laminate film 301 is folded in half. As will be described in more detail later, in this embodiment, the portion of the peripheral edge portion 82 between the folded portion 82a and the side surface 81a is folded along the side surface 81a.

[0028] The other three sides 8b to 8d include sealing portions 82b to 82d. The sealing portions 82b to 82d are formed by bonding the material of the exterior body 8 (laminate film 301) together by adhesive bonding, welding, or the like. On the opposing sides 8b and 8d of the three sides 8b to 8d, the lead tabs 3 and 4 are provided so as to cross the sealing portions 82b and 82d, respectively.

[0029] 1 , when the all-solid-state battery 1 is used in a battery module BM, the all-solid-state battery 1 is arranged so that a predetermined surface of the all-solid-state battery 1 is in contact with the heat transfer member 103. In this embodiment, in order to efficiently release heat from the all-solid-state battery 1 from the heat transfer member 103, a folded structure of the exterior body 8 described below is adopted.

[0030] Fig. 4 is a cross-sectional view taken along line B-B in Fig. 2A, showing the structure of the lower part of the all-solid-state battery 1. Fig. 5 is a front view of the all-solid-state battery 1, showing the state before the lower part of the exterior body 8 is folded. Note that in Fig. 4 (and Figs. 6A to 6C described below), the thicknesses and spacing of components are exaggerated in some places to make the structure easier to understand.

[0031] In this embodiment, a portion P1 of the peripheral edge portion 82 that is closer to the folded portion 82a than the side surface 81a of the storage portion 81 adjacent to the folded portion 82a is folded along the side surface 81a. Before the portion P1 is folded, the portion P1 on the folded portion 82a side is surrounded by the folded portion 82a, portions of the sealing portions 82b and 82d that are closer to the folded portion 82a than the side surface 81a in the Y direction, and a connection portion 82e between the side surface 81a and the peripheral edge portion 82. In other words, the portion P1 on the folded portion 82a side is the portion closer to the folded portion 82a than the connection portion 82e when viewed along the extension direction of the laminate film 301 that forms the exterior body 8. As a result, the peripheral edge portion 82 extends from the side surfaces 81b to 81d of the storage portion 81 in a direction substantially normal to the surface, whereas the peripheral edge portion 82 extends from the side surface 81a in a direction parallel to the surface. Therefore, the lower surface of the exterior body 8 in the direction shown in the drawing is flat.

[0032] That is, in the present embodiment, when the all-solid-state battery 1 is used in the battery module BM shown in Fig. 1 , the contact surface of the all-solid-state battery 1 with the heat transfer member 103 (here, the surface formed by the side surface 81a) is flat. This allows the heat transfer member 103 to be thinner than when the contact surface is uneven, and the heat transfer properties of the heat transfer member 103 can be improved (the thermal resistance of the heat transfer member 103 can be reduced). Therefore, heat from the all-solid-state battery 1 can be efficiently transferred to the cooling / heating element, and a decrease in the cooling / heating efficiency of the all-solid-state battery 1 can be suppressed.

[0033] Furthermore, in this embodiment, the portion P1 on the folded portion 82a side includes a region R1 extending from the connection portion 82e with the housing portion 81 to one side (positive side) in the stacking direction (Z direction) of the laminate 2, and a region R2 extending from the end of the region R1 on the positive side in the Z direction to the other side (negative side in the Z direction). By folding back the portion P1 on the folded portion 82a side to form the multiple regions R1 and R2, the unevenness of the contact surface between the all-solid-state battery 1 and the heat transfer member 103 is easily reduced. This reduces the likelihood of gaps or the like occurring between the all-solid-state battery 1 and the heat transfer member 103, making it easier for the all-solid-state battery 1 and the heat transfer member 103 to be in closer contact with each other, thereby efficiently transferring heat from the all-solid-state battery 1 to the cooling / heating element. This prevents a decrease in the efficiency of cooling or heating the all-solid-state battery 1.

[0034] Furthermore, in this embodiment, region R2 extends from an end on one side (positive side) to an end on the other side (negative side in the Z direction) in the stacking direction (Z direction) of the laminate 2. Therefore, region R2 is provided extending over substantially the entire stacking direction below the laminate 2, and therefore region R2 can form the contact surface with the heat transfer member 103 in the all-solid-state battery 1. Therefore, it is possible to further reduce unevenness on the contact surface between the all-solid-state battery 1 and the heat transfer member 103.

[0035] In the present embodiment, the portion P1 on the folded portion 82a side includes a region R3 that extends from the end of the region R2 on the negative side in the Z direction to the folded portion 82a on the positive side in the Z direction. This stabilizes the height of the portion P1 on the folded portion 82a side, and makes it possible to further reduce unevenness on the contact surface between the all-solid-state battery 1 and the heat transfer member 103.

[0036] Furthermore, in this embodiment, regions R1 and R3 are located closer to the laminate 2 than region R2. That is, region R2 is the region where portion P1 is folded back downward (toward the laminate 2) at the end of region R1 on the positive side in the Z direction. Region R3 is the region where portion P1 is folded back upward (toward the laminate 2) at the end of region R2 on the negative side in the Z direction. As a result, portion P1 on the folded portion 82a side and the heat transfer member 103 are in contact only in region R2, making it less likely that steps or the like will be formed on their contact surfaces. This further reduces unevenness on the contact surface between the all-solid-state battery 1 and the heat transfer member 103.

[0037] Furthermore, the length L1 (see FIG. 5) from the side surface 81a to the folded portion 82a is approximately twice the length Z1 (see FIG. 4) of the laminate 2 in the stacking direction. In other words, the length L1 is approximately twice the length Z1 of the accommodation portion 81 in the stacking direction. As a result, in the stacking direction (Z direction) of the laminate 2, the sum of the lengths of the regions R1 and R3 is approximately equal to the length of the region R2. Therefore, the thickness of the portion P1 on the folded portion 82a side in the Y direction is made uniform throughout the stacking direction (Z direction) of the laminate 2, thereby further reducing unevenness on the contact surface between the all-solid-state battery 1 and the heat transfer member 103. Here, approximately twice may indicate, for example, 1.95 to 2.05 times, 1.9 to 2.1 times, 1.8 to 2.2 times, or 1.7 to 2.3 times. That is, the relationship between the total length of the regions R1 and R3 and the length of the region R2 may be such that the unevenness of the contact surface between the all-solid-state battery 1 and the heat transfer member 103 can be easily reduced.

[0038] As will be described in the <Modification>, the length L1 may be equal to or greater than the length from the connecting portion 82e to either end in the Z direction of the housing portion 81. This allows the portion P1 on the folded-back portion 82a side to extend at least to the end in the Z direction of the housing portion 81, thereby preventing the portion P1 on the folded-back portion 82a side from being interrupted at a position where it overlaps with the side surface 81a in the Z direction, thereby preventing a step from occurring.

[0039] 3A and 3B, the structure of laminate film 301, which is a member forming exterior body 8, will be described. Laminate film 301 has an overall sheet-like shape, and as described above, recesses 311 and 321 are formed on both sides of folded portion 301a (corresponding to folded portion 82a of exterior body 8).

[0040] Recess 311 is a recess with a depth d1 relative to portion 310. Recess 321 is a recess with a depth d2 relative to portion 320. Note that, although depth d1 = depth d2 here, recesses 311 and 321 may have different depths. Recess 311 and recess 321 are spaced apart by a distance L2 in a direction intersecting the extension direction of folded portion 301a.

[0041] In this embodiment, the recesses 311 and 321 are arranged so that the distance L2 is equal to or greater than the sum of the depths d1 and d2. This allows the length of the portion P1 on the folded-back portion 82a side to be relatively long, making it easier to fold the portion P1 along the folded-back portion 82a. Furthermore, by making the distance L2 equal to or greater than the sum of the depths d1 and d2, the portion P1 on the folded-back portion 82a side can extend in the Z direction from the connecting portion 82e to the end of the housing portion 81 on the positive or negative side in the Z direction. Therefore, when the exterior body 8 is formed using the laminate film 301, the unevenness of the contact surface between the all-solid-state battery 1 and the heat transfer member 103 can be reduced.

[0042] Furthermore, in this embodiment, the recesses 311 and 321 are arranged so that the distance L2 is approximately four times the sum of the depths d1 and d2. This allows the regions R1 to R3 to be formed by folding the portion P1 on the folded-back portion 82a side when forming the exterior body 8 using the laminate film 301.

[0043] As a comparative example to this embodiment, first consider a case where all four sides 8a to 8d of the exterior body 8 are sealed (four-side sealing). In this case, the laminate film 301 is also sealed by adhesion, welding, or the like at the side 8a that forms the contact surface between the exterior body 8 and the heat transfer member 103. However, because the sealed area is harder than other areas, it may be difficult to fold the portion P1 on the folded portion 82a side along the side surface 81a. Therefore, in the case of four-side sealing, it may be difficult to flatten the contact surface with the heat transfer member 103 compared to the all-solid-state battery 1 of this embodiment.

[0044] Next, as a comparative example to this embodiment, consider a case where the distance L2 between the recess 311 and the recess 321 is short (insufficient). For example, if the distance L2 is only sufficient for folding back the laminate film 301, the portion P1 on the folded back portion 82a side will not be formed, or will be formed only to a length insufficient for folding. However, the sealed portions of the sides 8b and 8d may extend below the side surface 81a, resulting in large irregularities on the contact surface between the all-solid-state battery 1 and the heat transfer member 103.

[0045] In contrast to these comparative examples, in the present embodiment, the contact surface of the all-solid-state battery 1 with the heat transfer member 103 can be made relatively flat, so that the contact surface between the all-solid-state battery 1 and the heat transfer member 103 can be made larger, and the heat of the all-solid-state battery 1 can be more efficiently transferred to the cooling / heating element.

[0046] Furthermore, if there are irregularities at the contact portion between the all-solid-state battery 1 and the heat transfer member 103, it is necessary to make the heat transfer member 103 thicker in the Y direction to absorb the irregularities. In the present embodiment, the irregularities at the contact surface between the all-solid-state battery 1 and the heat transfer member 103 are suppressed, so the heat transfer member 103 can be made thinner in the Y direction compared to the comparative example described above. Furthermore, since the heat transfer member 103 is made thinner, the laminate 2 can be made larger in the Y direction in a battery module BM of the same size, which can also contribute to improving the energy density of the battery module BM.

[0047] Furthermore, in this embodiment, when the all-solid-state battery 1 is used in a battery module BM, the portion P1 on the folded portion 82a side comes into contact with the heat transfer member 103, and therefore the side surface 81a of the housing portion 81 does not come into contact with the heat transfer member 103. Here, when the side surface 81a of the housing portion 81 comes into contact with the heat transfer member 103, the side surface 81a also expands and contracts in response to the expansion and contraction of the laminate 2. Therefore, when the gel-like heat transfer member 103 is adhered to the side surface 81a in consideration of heat transfer, it is necessary to ensure the thickness of the heat transfer member 103 so that the gel-like heat transfer member 103 expands in response to the expansion of the side surface 81a. However, in this embodiment, the portion P1 on the folded portion 82a side, which does not expand and contract with the laminate 2, comes into contact with the heat transfer member 103, and therefore it is not necessary to consider the expansion of the gel-like heat transfer member 103. From this perspective, the heat transfer member 103 can be made thinner in the Y direction in this embodiment.

[0048] 6A to 6C are diagrams showing modifications of the exterior body 8 of the above embodiment. Hereinafter, a description of the same configuration as the above embodiment will be omitted.

[0049] 6A differs from the exterior body 8 of the above embodiment mainly in that a portion P61 on the folded-back portion 682a side does not include region R3. That is, the portion P61 on the folded-back portion 682a side is folded back at two locations: the connection portion 82e with the housing portion 81, and the boundary between region R1 and region R2. Even with this configuration, it is possible to suppress unevenness on the contact surface with the heat transfer member 103 of the all-solid-state battery 1.

[0050] 6B differs from the exterior body 8 of the above embodiment mainly in that the portion P71 on the folded-back portion 782a side is provided so as to be wider than the width of the laminate 2 in the Z direction. According to this modification, the area of ​​the flat contact surface between the all-solid-state battery 1 and the heat transfer member 103 can be increased, thereby further improving heat transfer. In this manner, a part of the portion P71 on the folded-back portion 782a side may be folded along the side surface 81a, and the remaining part may be provided in a position that does not follow the side surface 81a, or the entire portion P1 may be folded along the side surface 81a as in the above embodiment.

[0051] The exterior body 808 in FIG. 6C differs from the exterior body 8 of the above embodiment mainly in that a connection portion 882e between the accommodation portion 881 and the portion P81 on the folded-back portion 882a side is provided at the Z-direction end of the accommodation portion 881. If the laminate film forming the exterior body 808 has only one recess forming the accommodation portion 881, folding the exterior body 808 results in the connection portion 882e being provided at the Z-direction end. In such a case, the portion P81 region R1 is formed in the Z direction from the end where the connection portion 882e is provided to the other end, thereby suppressing unevenness of the contact surface with the heat transfer member 103 of the all-solid-state battery 1. In other words, the Z-direction position of the connection portion 882e between the accommodation portion 81 of the exterior body 8 and the portion P1 on the folded-back portion 882a side can be changed as appropriate.

[0052] FIG. 7 is a diagram showing a modified lower structure of an all-solid-state battery. The all-solid-state battery 901 of this modified example differs from the all-solid-state battery 1 of the above embodiment in that grease 9, a highly viscous fluid, is applied to the portion P1 on the folded portion 82a side. For example, the all-solid-state battery 901 is folded with the grease 9 applied to the portion P1 on the folded portion 82a side before folding (see FIG. 5 ). Alternatively, the grease 9 may be applied to the portion P1 on the folded portion 82a side after folding. Note that, in this example, the grease 9 is present between the side surface 81a of the exterior body 8 and the regions R1 and R3, and between the regions R1 and R3 and the region R2. However, the arrangement of the grease 9 can be changed as appropriate. For example, in FIG. 7 , no grease is provided between the region R2 and the heat transfer member 103 because an air layer is unlikely to form between these two regions. However, grease 9 may be applied between these two regions.

[0053] In the all-solid-state battery 1 of the above embodiment, the folded laminates (e.g., regions R1 and R2) of the portion P1 on the folded-back portion 82a side come into contact with each other, but strictly speaking, an air layer exists between them. This air layer may hinder heat transfer from the all-solid-state battery 1 to the heat transfer member 103.

[0054] On the other hand, in this modification, the presence of grease 9 in the gaps of the folded portion P1 can prevent air from getting between the folded laminates, improving the adhesion between the laminates. Therefore, heat can be more effectively transferred from the all-solid-state battery 1 to the heat transfer member 103. Furthermore, the use of grease 9 makes it possible to follow the expansion of the laminate 2 and further reduce the thickness, thereby further improving heat transfer.

[0055] The base oil component of the grease, which is a highly viscous fluid, can be mineral oil, silicone, etc. When grease is used as the highly viscous fluid, it is possible to use grease with an ASTM (JIS) consistency of 1 to 6, for example, in order to reduce pump-out.

[0056] Furthermore, in the description of the above embodiment, an all-solid-state battery 1 having a laminate 2 including a solid electrolyte layer 27 as a power generating element is given as an example, but the features of the above embodiment can also be applied to other storage batteries in which a power generating element is pouched with a laminate material. For example, the features of the above embodiment can also be applied to storage batteries such as lithium ion batteries that include an electrolytic solution or a gel electrolyte as an electrolyte.

[0057] Summary of the Embodiments The above-described embodiments disclose at least the following storage battery, battery module, and laminate film.

[0058] 1. According to the above embodiment, there is provided a storage battery (1) comprising: a power generating element (2); and an exterior body (8) that encases the power generating element, wherein the exterior body is formed by folding a member (301) that forms the exterior body in half at a folded portion (82a, 320), and the exterior body includes a housing section (81) that houses the power generating element; and a peripheral portion (82) around the housing section that includes the folded portion, wherein a first portion (P1) of the peripheral portion that is closer to the folded portion than a side surface (81a) of the housing section that is adjacent to the folded portion is folded along the side surface.

[0059] According to this embodiment, the portion of the peripheral edge closer to the folded portion than the side surface of the housing adjacent to the folded portion is folded along the side surface, so that the exterior body tends to be flat at this folded portion. Therefore, when this portion comes into contact with the heat transfer member, the contact area can be increased, and heat from the storage battery can be efficiently transferred to the cooling / heating element.

[0060] 2. According to the above embodiment, there is provided a storage battery, wherein the first portion includes a first region (R1) extending from a connection portion (82e) with the housing portion to one side in the thickness direction of the power-generating element, and a second region (R2) extending from an end of the one side of the first region to the other side opposite to the one side.

[0061] According to this embodiment, the portion on the folded-back side is folded back to form multiple regions, which reduces the unevenness of the contact surface between the storage battery and the heat transfer member, making it less likely for gaps to form between the storage battery and the heat transfer member and allowing the storage battery and the heat transfer member to be in closer contact with each other, thereby enabling the storage battery's heat to be efficiently transferred to the cooling / heating element.

[0062] 3. According to the above embodiment, there is provided a storage battery, wherein the first portion includes a third region (R3) extending to the one side from the other end of the second region to the folded portion.

[0063] According to this embodiment, the height of the folded portion side is stable, and unevenness in the contact surface between the storage battery and the heat transfer member can be further reduced.

[0064] 4. According to the above embodiment, there is provided a storage battery, in which the first region and the third region are located closer to the power generating element than the second region.

[0065] According to this embodiment, the folded portion and the heat transfer member are in contact only in the second region, which makes it difficult for steps or the like to form on their contact surfaces, thereby further reducing unevenness on the contact surfaces between the storage battery and the heat transfer member.

[0066] 5. According to the above embodiment, there is provided a storage battery, in which the second region extends in the thickness direction from the position of the end on the one side of the power-generating element to the position of the end on the other side.

[0067] According to this embodiment, the second region extends substantially across the entire thickness of the stack below the stack, so that the contact surface of the storage battery with the heat transfer member can be configured by the second region, thereby further reducing unevenness on the contact surface between the storage battery and the heat transfer member.

[0068] 6. According to the above embodiment, there is provided a storage battery, in which the length (L1) from the side surface to the folded portion is approximately twice the length of the power-generating element in the thickness direction.

[0069] According to this embodiment, the total length of the first region and the third region is approximately equal to the total length of the second region in the thickness direction of the stack, thereby further reducing unevenness on the contact surface between the storage battery and the heat transfer member.

[0070] 7. According to the above embodiment, there is provided a storage battery, in which the length (L1) from the side surface to the folded-back portion is equal to or greater than the length from the connection portion of the first portion with the housing portion to either end of the housing portion in the thickness direction of the power-generating element.

[0071] According to this embodiment, the portion on the folded portion side can be extended at least to the end of the storage section in the thickness direction, thereby preventing the portion on the folded portion side from being interrupted at the position where it overlaps with the adjacent side surface in the thickness direction, thereby preventing a step from being created.

[0072] 8. According to the above embodiment, there is provided a storage battery, wherein the first portion is folded in a state in which a highly viscous fluid is applied to the first portion.

[0073] According to this embodiment, it is possible to prevent an air layer from being formed between the members when the portion on the folded-back side is folded, and it is possible to prevent a decrease in heat transfer.

[0074] 9. According to the above embodiment, there is provided a storage battery, wherein the power generating element is a laminate (2) in which positive electrode layers (21A, 21B), a solid electrolyte layer (27), and negative electrode layers (21B, 24B) are laminated.

[0075] According to this embodiment, the heat of the storage battery can be efficiently transferred to the cooling / heating element.

[0076] 10. According to the above embodiment, a battery module (BM) is provided, comprising: a storage battery according to any one of 1 to 8 above; and a heat transfer member (103) arranged to cool / heat the storage battery and to be in contact with the first portion of the storage battery.

[0077] According to this embodiment, a cooling / heating battery module is provided that can more efficiently release heat from the storage battery through the heat transfer member.

[0078] 11. According to the above embodiment, there is provided a battery module further comprising a cooling / heating means (102) for cooling or heating the storage battery, and the heat transfer member is disposed between the storage battery and the cooling / heating means.

[0079] 12. According to the above embodiment, there is provided a laminate film (301) forming an exterior body (8) that encases a power generating element (2), wherein the exterior body is formed by folding the laminate film in half at a folded portion (82a), the exterior body includes a storage section (81) that stores the power generating element, and a peripheral portion (82) around the storage section, the laminate film has: a first recess (311) that is provided on one side (310) of the folded portion and forms the storage section; and a second recess (321) that is provided on the other side (320) of the folded portion opposite the one side at a position corresponding to the first recess and forms the storage section, and a distance (L2) between the first recess and the second recess is equal to or greater than the sum of the depths (d1, d2) of the first recess and the second recess.

[0080] According to this embodiment, it is possible to form an exterior body that suppresses unevenness in the contact portion with the heat transfer member when used in a battery module.

[0081] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention.

[0082] 1: all-solid-state battery, 2: laminate, 8: exterior body, 81: housing portion, 82: peripheral portion, 82a: folded portion, 301: laminate film, BM: battery module

Claims

1. A power generation element; and an exterior body that encases the power generating element, The exterior body is formed by folding a member forming the exterior body in half at a folded-back portion, The exterior body is a housing section that houses the power generating element; a peripheral portion around the housing portion including the folded portion; a first portion of the peripheral portion, the first portion being closer to the folded-back portion than a side surface of the storage portion adjacent to the folded-back portion, is folded along the side surface; A storage battery characterized by:

2. 2. The battery of claim 1 , The first portion is a first region extending from a connection portion with the housing portion to one side in a thickness direction of the power generating element; a second region extending from an end of the first region on one side to an opposite side to the one side, A storage battery characterized by:

3. The storage battery according to claim 2, The first portion includes a third region extending to the one side from the other end of the second region to the folded portion. A storage battery characterized by:

4. The storage battery according to claim 3, the first region and the third region are located closer to the power generating element than the second region; A storage battery characterized by:

5. A storage battery according to any one of claims 2 to 4, The second region extends in the thickness direction from the end of the power generating element on one side to the end of the power generating element on the other side. A storage battery characterized by:

6. 2. The battery of claim 1 , The length from the side surface to the folded portion is approximately twice the length of the power generating element in the thickness direction. A storage battery characterized by:

7. 2. The battery of claim 1 , a length from the side surface to the folded portion is equal to or greater than a length from a connection portion of the first portion with the housing portion to any end portion of the housing portion in a thickness direction of the power generating element; A storage battery characterized by:

8. A storage battery as claimed in claim 5, The first portion is folded in a state in which a highly viscous fluid is applied thereto. A storage battery characterized by:

9. A storage battery according to any one of claims 1 to 4, 6 and 7, The first portion is folded in a state in which a highly viscous fluid is applied thereto. A storage battery characterized by:

10. A storage battery as claimed in claim 5, The power generating element is a laminate in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are laminated. A storage battery characterized by:

11. A storage battery according to any one of claims 1 to 4, 6 and 7, The power generating element is a laminate in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are laminated. A storage battery characterized by:

12. A storage battery according to claim 5, a heat transfer member disposed in contact with the first portion of the battery. A battery module comprising:

13. A storage battery according to any one of claims 1 to 4, 6 and 7, a heat transfer member disposed in contact with the first portion of the battery. A battery module comprising:

14. The battery module according to claim 12, The storage battery further includes a cooling / heating means for cooling or heating the storage battery, The heat transfer member is disposed between the storage battery and the cooling / heating means. A battery module comprising:

15. The battery module of claim 13, The storage battery further includes a cooling / heating means for cooling or heating the storage battery, The heat transfer member is disposed between the storage battery and the cooling / heating means. A battery module comprising:

16. A laminate film that forms an exterior body by wrapping a power generating element, The exterior body is formed by folding the laminate film in half at a folded portion, The exterior body is a housing section that houses the power generating element; a periphery around the housing; The laminate film is a first recess provided on one side of the folded portion and forming the storage portion; a second recess provided on the other side of the folded portion opposite to the one side and corresponding to the first recess, the second recess forming the storage portion; a distance between the first recess and the second recess is equal to or greater than a sum of the depths of the first recess and the second recess; A laminate film characterized by the above.