Battery pack

Abstract

A battery pack according to one aspect of the present technology is provided with batteries, and a heat absorbing member having a heat absorbing agent and a container that accommodates the heat absorbing agent. The heat absorbing member is disposed at a position adjacent to the batteries. The container has a laminate including a resin layer and a metal layer in this order from the heat-absorbing agent side. The laminate has a hole penetrating the resin layer and the metal layer. The periphery of the hole is sealed by a resin layer around the hole.

Description

Battery pack

[0001] The present technology relates to battery packs.

[0002] As electronic devices have become widespread, development of batteries as power sources for these devices has progressed. In this case, battery packs containing multiple batteries have been proposed to facilitate easy and safe handling of the batteries.

[0003] Various studies have been conducted on technologies related to the configuration of battery packs. For example, Patent Document 1 discloses a method in which a heat-absorbing member is brought into contact with a battery in a battery unit and the heat-absorbing member is used to cool the battery when it generates abnormal heat.

[0004] International Publication No. 2010 / 098067

[0005] However, in battery packs, depending on the arrangement and structure of the heat-absorbing member, it may be difficult to sufficiently cool a battery that has generated abnormal heat with the heat-absorbing member. It is desirable to provide a battery pack that can sufficiently cool a battery that has generated abnormal heat with the heat-absorbing member.

[0006] A battery pack according to a first aspect of the present technology includes a battery, a heat-absorbing agent, and a heat-absorbing member having a container for accommodating the heat-absorbing agent. The heat-absorbing member is disposed adjacent to the battery. The container has a laminate including a resin layer and a metal layer, in this order from the heat-absorbing agent side. The laminate has a hole penetrating the resin layer and the metal layer. The periphery of the hole is sealed by the resin layer surrounding the hole.

[0007] A battery pack according to a second aspect of the present technology includes a battery, a heat-absorbing member having a heat-absorbing agent and a container for accommodating the heat-absorbing agent. Both the battery and the container are flat. The container has a first surface disposed adjacent to the battery, a second surface facing the first surface across the heat-absorbing agent, and a through hole penetrating the first surface and the second surface. The periphery of the through hole is sealed by a peripheral portion of the first surface and a peripheral portion of the second surface.

[0008] According to the battery pack according to the first aspect of the present technology, the container containing the heat-absorbing agent is formed of a laminate including a resin layer and a metal layer, and the periphery of a hole penetrating the laminate is sealed with the resin layer surrounding the hole. Therefore, the heat of a battery that has generated abnormal heat causes the welded portion of the resin layer to peel off, and the heat-absorbing agent released from the hole comes into contact with the battery that has generated abnormal heat, thereby cooling the battery that has generated abnormal heat. Thus, by providing the welded portion of the resin layer at a desired location on the container, the battery that has generated abnormal heat can be effectively cooled. Therefore, the battery that has generated abnormal heat can be sufficiently cooled by the heat-absorbing member.

[0009] According to a battery pack according to a second aspect of the present technology, the periphery of a through hole penetrating the first and second surfaces of a container containing a heat-absorbing agent is sealed by the portion of the first surface surrounding the through hole and the portion of the second surface surrounding the through hole. Therefore, the heat of an abnormally heated battery causes the welded portion of the container to peel off, allowing the heat-absorbing agent released from the container to come into contact with the abnormally heated battery and cool the abnormally heated battery. Thus, by providing the welded portion at a desired location on the container, the abnormally heated battery can be effectively cooled. Therefore, the abnormally heated battery can be sufficiently cooled by the heat-absorbing member.

[0010] Note that the effects of the present technology are not necessarily limited to the effects described here, but may be any of a series of effects related to the present technology described below.

[0011] FIG. 1 is a diagram illustrating an example of a perspective configuration of a battery pack according to an embodiment of the present technology. FIG. 2 is a diagram illustrating an example of a perspective configuration of a battery module accommodated in the battery pack of FIG. 1. FIG. 3 is a diagram illustrating an example of an exploded perspective configuration of the battery pack of FIG. 1. FIG. 4 is a diagram illustrating an example of a cross-sectional configuration of the battery module of FIG. 2. FIG. 5 is a diagram illustrating an example of a perspective configuration of the heat absorption module of FIG. 4. FIG. 6(A) is a diagram illustrating an example of a perspective configuration of the heat absorption member of FIG. 5. FIG. 6(B) is a diagram illustrating an example of a cross-sectional configuration of the heat absorption member of FIG. 6(A) taken along line A-A. FIG. 6(C) is a diagram illustrating an example of a cross-sectional configuration of the heat absorption member of FIG. 6(A) taken along line B-B. FIG. 7 is a diagram illustrating an example of a cross-sectional configuration of a portion of the heat absorption member of FIG. 6(A). FIG. 8(A) is a diagram illustrating an enlarged view of an example of a cross-sectional configuration of a portion of FIG. 6(B). FIG. 8(B) is a diagram illustrating an enlarged view of an example of a cross-sectional configuration of a portion of FIG. 6(C). FIG. 8(C) is an enlarged view of an example cross-sectional configuration of a portion of the flange portion of FIG. 6(A). FIG. 9 is a view showing an example side configuration of the heat-absorbing member of FIG. 6(A). FIG. 10 is an enlarged view of an example perspective configuration of a portion of the heat-absorbing member of FIG. 6(A). FIG. 11(A) is a view showing an example of a manufacturing process for holes. FIG. 11(B) is a view showing an example of a manufacturing process subsequent to FIG. 11(A). FIG. 11(C) is a view showing an example of a manufacturing process subsequent to FIG. 11(B). FIG. 12 is a view showing a modified cross-sectional configuration of the heat-absorbing member of FIG. 8(B). FIG. 13(A) is a view showing a modified perspective configuration of the heat-absorbing member of FIG. 6(A). FIG. 13(B) is a view showing an example cross-sectional configuration of the heat-absorbing member of FIG. 13(A) taken along line A-A. FIG. 13(C) is a view showing an example cross-sectional configuration of the heat-absorbing member of FIG. 13(A) taken along line B-B. Fig. 14 is a diagram showing a modified planar configuration of the battery module of Fig. 2. Fig. 15 is a diagram showing an example of an expanded perspective configuration of the battery module of Fig. 14. Fig. 16 is a diagram showing an example of a perspective configuration of the heat-absorbing member of Fig. 15. Fig. 17 is a diagram showing an example of a cross-sectional configuration of the heat-absorbing member of Fig. 16 taken along line A-A. Fig. 18 is a diagram showing a modified cross-sectional configuration of the heat-absorbing member of Fig. 15. Fig. 19 is a diagram showing a modified cross-sectional configuration of the heat-absorbing member of Fig. 17. Fig. 20 is a diagram showing a modified cross-sectional configuration of the heat-absorbing member of Fig. 18.

[0012] Hereinafter, embodiments of the present technology will be described in detail with reference to the drawings.

[0013] First, a battery pack according to an embodiment of the present technology will be described.

[0014] The battery pack described here is a power supply including multiple batteries, and is applicable to a variety of uses, such as electronic devices. The uses of the battery pack will be described in detail below. The type of battery is not particularly limited, and may be a primary battery or a secondary battery. The type of secondary battery is not particularly limited, and specifically, may be a lithium-ion secondary battery, which obtains battery capacity by utilizing the absorption and release of lithium ions. The number of batteries is not particularly limited, and may be set as desired. The following describes the case where the batteries are secondary batteries (lithium-ion secondary batteries). In other words, the battery pack described below is a power supply including multiple secondary batteries.

[0015] Fig. 1 illustrates an example of a perspective configuration of a battery pack 1 according to an embodiment of the present technology. Fig. 2 illustrates an example of a perspective configuration of a battery module 20 housed in the battery pack 1. Fig. 3 illustrates an example of an exploded perspective configuration of the battery pack 1. Fig. 4 illustrates an example of a cross-sectional configuration of the battery module 20.

[0016] 1 to 3, the battery pack 1 includes an outer case 10, a battery module 20, a plurality of metal tabs 60, and a control board 70. The control board 70 is connected to the positive and negative terminals of the battery module 20 via the plurality of metal tabs 60, for example, and has circuits that measure the voltage of the battery and the battery module 20, detect the remaining capacity of the battery module 20, and measure the current output from the battery module 20 to detect the presence or absence of an overcurrent.

[0017] The exterior case 10 houses the battery modules 20, the plurality of metal tabs 60, and the control board 70. For example, as shown in FIG. 3 , the exterior case 10 is composed of a lower case 10a and an upper case 10b. The lower case 10a and the upper case 10b are stacked together to form a housing space for housing the battery modules 20, the plurality of metal tabs 60, and the control board 70. The exterior case 10 (for example, the lower case 10a) is provided with external terminals 11 connected to the control board 70. The battery modules 20 are connected to the external terminals 11 via the control board 70.

[0018] The battery pack 1 has a discharge mode in which it supplies power output from the battery module 20 to a load via the external terminal 11. The battery pack 1 may also have a charge mode in which it stores power supplied via the external terminal 11 from a power source connected to the external terminal 11 in the battery module 20. When the battery 30 described below is a secondary battery, the control board 70 switches between the discharge mode and the charge mode depending on the type of connection object connected to the external terminal 11. When the battery 30 described below is a primary battery, the control board 70 operates only in the discharge mode.

[0019] The battery module 20 includes a plurality of batteries 30, as shown in FIGS. 2 and 3 , for example. The batteries 30 are electrically connected via a plurality of metal tabs 60. Each battery 30 includes a positive electrode 31 and a negative electrode 32, as shown in FIG. 2 , for example. Each battery 30 is a cylindrical battery in which the positive electrode 31 and the negative electrode 32 extend in directions facing each other. In the battery module 20, for example, some of the plurality of batteries 30 are connected in series with each other via a plurality of metal tabs 60. Furthermore, when the plurality of batteries 30 connected in series are referred to as a series unit, the series units are connected in parallel with each other via a plurality of metal tabs 60. Note that the connection of the plurality of batteries 30 is not limited to the above.

[0020] Each metal tab 60 is formed, for example, by a metal lead plate. Each battery 30 is a primary battery or a secondary battery. If each battery 30 is a secondary battery, the type of secondary battery is not particularly limited, but specifically, it may be a lithium-ion secondary battery that obtains battery capacity by utilizing the absorption and release of lithium ions. The following describes a case where each battery 30 is a secondary battery (lithium-ion secondary battery). In other words, the battery pack 1 described below is a power source including multiple secondary batteries.

[0021] 2 and 3, the battery module 20 further includes a battery holder 40 that supports the plurality of batteries 30, and a plurality of heat-absorbing members 50 arranged between the plurality of batteries 30. The battery holder 40 has a structure that supports the plurality of batteries 30 in a tiered manner with a predetermined gap between them. The heat-absorbing members 50 will be described in detail later.

[0022] Fig. 4 shows an example of the cross-sectional configuration of the battery module 20. The battery holder 40 is composed of a pair of holders 40a and 40b, as shown in Fig. 3 and Fig. 4. Both holders 40a and 40b have a common structure.

[0023] Each of the holders 40a and 40b has a side plate 41, as shown in Fig. 4 . The side plate 41 of the holder 40a and the side plate 41 of the holder 40b are arranged opposite each other with the plurality of batteries 30 between them in the extension direction of each battery 30 (the direction in which the positive electrodes 31 and negative electrodes 32 face each other). In the holders 40a and 40b, the side plate 41 has openings 42 at locations facing the positive electrodes 31 and negative electrodes 32 of each battery 30. Therefore, the positive electrodes 31 or negative electrodes 32 are exposed in the openings 42.

[0024] Each of the holders 40a, 40b further includes a support portion 43 that supports multiple batteries 30 in a tiered configuration with a predetermined gap between them, as shown in FIG. 4 . A side plate portion 41 is connected to each end of the support portion 43. Assume that the support portion 43 supports four or more cylindrical batteries 30 in a tiered configuration with a predetermined gap between them. In this case, the support portion 43 has an opening 44 at a location surrounded by four adjacent cylindrical batteries 30, as shown in FIG. 4 . A heat absorption module 50m, consisting of two overlapping heat absorption members 50, is positioned in a location surrounded by the four adjacent cylindrical batteries 30, as shown in FIGS. 4 and 5 , and contacts the outer peripheries of the four cylindrical batteries 30 through the opening 44.

[0025] The heat absorption module 50m extends in a direction parallel to the extension direction of each battery 30 (the direction in which the positive electrodes 31 and negative electrodes 32 face each other). Each heat absorption member 50 constituting the heat absorption module 50m also extends in a direction parallel to the extension direction of each battery 30 (the direction in which the positive electrodes 31 and negative electrodes 32 face each other). In the heat absorption module 50m, one heat absorption member 50 contacts the outer peripheral surfaces of two upper batteries 30 of the four adjacent cylindrical batteries 30, and the other heat absorption member 50 contacts the outer peripheral surfaces of two lower batteries 30 of the four adjacent cylindrical batteries 30. In the heat absorption module 50m, the flat surfaces (flat surface S4 (see FIG. 6B ) described below) of the two heat absorption members 50 overlap each other. The opening 44 contacts the side plate portion 41 of the holder 40a and the side plate portion 41 of the holder 40b, and the heat absorption member 50 contacts the side plate portion 41 of the holder 40a and the side plate portion 41 of the holder 40b through the opening 44.

[0026] FIG. 6A shows an example of a perspective configuration of the heat absorption member 50. FIG. 6B shows an example of a cross-sectional configuration of the heat absorption member 50 taken along line A-A. FIG. 6C shows an example of a cross-sectional configuration of the heat absorption member 50 taken along line B-B. The heat absorption member 50 has a shape corresponding to the shape of the gaps between the multiple batteries 30 supported by the battery holder 40 (support portion 43). The heat absorption member 50 has an elongated columnar shape. Assume that four or more cylindrical batteries 30 are supported in a tiered configuration by the battery holder 40 (support portion 43) with a predetermined gap between them. A heat absorption module 50m, consisting of two overlapping heat absorption members 50, contacts the surfaces (outer peripheral surfaces) of the four adjacent cylindrical batteries 30 and has a shape corresponding to the shape of the gaps between the four adjacent cylindrical batteries 30, for example. The cross section of the heat absorption module 50m taken perpendicular to the extension direction of the heat absorption module 50m is generally diamond-shaped. At this time, for example, as shown in FIG. 6B, the cross section of the heat absorbing member 50 in a direction perpendicular to the extending direction of the heat absorbing member 50 has a substantially triangular shape.

[0027] Here, the two adjacent cylindrical batteries 30 are referred to as the first battery 30 and the second battery 30. In this case, the heat absorption member 50 has an arc wall W1 (arc surface S1) extending along the outer circumferential surface of the first battery 30 and an arc wall W2 (arc surface S2) extending along the outer circumferential surface of the second battery 30. The arc wall W2 is disposed adjacent to the arc wall W1. The two arc walls W1, W2 (or the two arc surfaces S1, S2) have a concave shape following the outer circumferential surfaces of the batteries 30. The arc wall W1 corresponds to a specific example of a "first stacked portion" of the present technology. The arc wall W2 corresponds to a specific example of a "second stacked portion" of the present technology. The heat absorption member 50 further has end walls W3 at both longitudinal ends of the heat absorption member 50 that constitute part of the longitudinal ends of the heat absorption member 50, and has flat walls W4 (flat surfaces S4) at locations facing the arc walls W1 and W2 across the heat absorption agent 54 described below. The end walls W3 are disposed in positions adjacent to both the arc walls W1 and W2. The end walls W3 correspond to a specific example of a "third stacked portion" of the present technology.

[0028] The heat absorbing member 50 includes, for example, a heat absorbing agent 54 and a container 51 that covers the heat absorbing agent 54, as shown in FIG. 6B.

[0029] The container 51 covers the heat-absorbing agent 54. The container 51 is formed, for example, by heat-sealing a laminated portion 52A (described later) and a laminated portion 52B (described later) on one side of the container, filling the container with the heat-absorbing agent 54, and then heat-sealing the filling port on the remaining side. Thus, the container 51 contains the heat-absorbing agent 54. The molded laminate 52 is composed of the laminated portion 52A and the laminated portion 52B, for example, as shown in FIG. 6B . The laminated portion 52A forms the arc walls W1 and W2 and the end wall W3, and the laminated portion 52B forms the flat wall W4. The laminated portion 52A and the laminated portion 52B are, for example, integrally formed with each other and connected to each other at a flange portion 51B (described later).

[0030] 5 and 6A, the container 51 has a storage section 51A that stores the heat-absorbing agent 54, and a flange section 51B formed around the storage section 51A. The storage section 51A corresponds to a substantially triangular prism-shaped portion of the container 51 that is formed by the arc walls W1 and W2, the end wall W3, and a portion of the flat wall W4. The flange section 51B corresponds to a plate-shaped portion of the container 51 that is formed to surround the storage section 51A when viewed from the normal direction of the flat wall W4.

[0031] The container 51 (laminate 52, laminated portion 52A, laminated portion 52B) is configured to include a resin layer formed of a thermoplastic material. The container 51 (laminate 52, laminated portion 52A, laminated portion 52B) is configured to include, for example, a resin layer 52a as shown in Fig. 7. The resin layer 52a is configured from a resin material such as polyethylene, polystyrene, polypropylene, polycarbonate, or the like.

[0032] The container 51 (laminate 52, laminated portion 52A, laminated portion 52B) may be made of, for example, a laminate film. For example, as shown in FIG. 7 , the container 51 (laminate 52, laminated portion 52A, laminated portion 52B) is made of a resin layer 52a and a metal layer 52b in this order from the heat-absorbing agent 54 side. In this case, the container 51 (laminate 52, laminated portion 52A, laminated portion 52B) is made of a resin layer 52a. The metal layer 52b is made of, for example, a metal foil such as aluminum foil.

[0033] The heat-absorbing agent 54 is made of, for example, a liquid containing water or a hydrogel. When using a hydrogel as the heat-absorbing agent 161, it is preferable to use a synthetic polymer gel. Examples of materials for the synthetic polymer gel include sodium polyacrylate (PNaAA), polyvinyl alcohol (PVA), polyhydroxyethyl methacrylate (PHE-MA), and silicone hydrogel.

[0034] 8(A) and 8(B) are enlarged views of the folded portion of the storage section 51A provided in the stacked portion 52A. FIG. 8(A) is an enlarged view of the folded portion taken along line A-A in FIG. 6(A). FIG. 8(B) is an enlarged view of the folded portion taken along line B-B in FIG. 6(A). FIG. 8(C) is an enlarged view of the flange portion 51B. FIG. 9 shows an example of the side configuration of the heat absorption member 50. FIG. 10 is an enlarged view of a portion of the heat absorption member 50.

[0035] As shown in Figures 6(B) and 8(A), the laminated portion 52A has a shape bent at an acute angle at the boundary α between the arcuate wall W1 and the arcuate wall W2. At the boundary α (bent portion) between the arcuate wall W1 and the arcuate wall W2, a portion of the resin layer 52a of the arcuate wall W1 and a portion of the resin layer 52a of the arcuate wall W2 are welded to each other, as shown in Figures 8(A) and 9. At the boundary α (bent portion) between the arcuate wall W1 and the arcuate wall W2, a portion of the resin layer 52a of the arcuate wall W1 and a portion of the resin layer 52a of the arcuate wall W2 are sealed by adhesion, for example. The portion where the portion of the resin layer 52a of the arcuate wall W1 and the portion of the resin layer 52a of the arcuate wall W2 are welded (sealed) to each other is a welded portion 52C in Figures 8(A) and 9. At the end of the flange portion 51B, for example, as shown in Fig. 8(C), a portion of the resin layer 52a of the arcuate wall W2 and a portion of the resin layer 52a of the flat wall W4 are welded to each other. At the end of the flange portion 51B, for example, a portion of the resin layer 52a of the arcuate wall W2 and a portion of the resin layer 52a of the flat wall W4 are sealed by adhesion. In Fig. 8(C), the portion where a portion of the resin layer 52a of the arcuate wall W2 and a portion of the resin layer 52a of the flat wall W4 are welded (sealed) to each other is a welded portion 52D.

[0036] The flange portion 51B does not have any notches or through-holes, as shown in FIG. 8C . Therefore, the flange portion 51B is covered with a metal layer 52b, preventing the heat-absorbing agent 54 from being released to the outside from the flange portion 51B. Meanwhile, the stacked portion 52A has one or more notches 51C at the boundary α (bending portion) between the arc-shaped wall W1 and the arc-shaped wall W2, as shown in FIGS. 6C , 8B , 9 , and 10 . The one or more notches 51C are disposed adjacent to the circumferential surfaces of both the first battery 30 and the second battery 30. The one or more notches 51C are disposed at a position spaced apart from the end wall W3. Each notch 51C is disposed in the longitudinal center region of the container 51. Here, the "central region" refers to, for example, a region at the boundary α (folded portion) between the two end walls W3, which is separated from the end wall W3 by a length equal to the height of the end wall W3.

[0037] As shown in Figures 8(B) and 10, a welded portion 52C is exposed on the surface of each cutout portion 51C. That is, each cutout portion 51C penetrates the stacked portion 52A. Therefore, when the welded portion 52C in each cutout portion 51C melts due to the heat of, for example, an abnormally hot battery 30, the heat-absorbing agent 54 leaks out through each cutout portion 51C (e.g., to the periphery of the abnormally hot battery 30). Therefore, each cutout portion 51C has a hole 51D penetrating the stacked portion 52A. For example, as shown in Figure 9, the periphery of the hole 51D is welded by the welded portion 52C. Furthermore, as shown in Figure 10, for example, the hole 51D is welded by the welded portion 52C.

[0038] Next, a method for manufacturing the hole 51D will be described. Figures 11A to 11C illustrate an example of the manufacturing process for the hole 51D. First, a mountain-shaped laminate 52 is prepared (Figure 11A). Next, the ridge of the mountain-shaped portion of the laminate 52 is sandwiched between two flat mold pieces, and in this state, each mold piece is heated to a predetermined temperature. As a result, the heat from each mold piece is transmitted to the resin layer 52a in the laminate 52, welding a portion of the resin layer 52a to form a welded portion 52C (Figure 11B). Next, one or more cutout portions 51C are formed in the laminate 52 at the locations where the welded portion 52C is formed. This forms a hole 51D in the cutout portion 51C (Figure 11C). In this manner, the hole 51D is manufactured.

[0039] Next, the effects of the battery pack 1 will be described.

[0040] As electronic devices have become widespread, development of batteries as power sources for these devices has progressed. In this case, battery packs containing multiple batteries have been proposed to facilitate easy and safe handling of the batteries.

[0041] Various studies have been conducted on technologies related to the configuration of a battery pack. Specifically, a heat-absorbing member is in contact with the side surface of a battery unit, and the heat-absorbing member contains a heat-absorbing agent (gel-like fluid) inside an exterior film (see, for example, Patent Document 1).

[0042] However, in a battery pack, depending on the arrangement and structure of the heat absorbing member, it may be difficult for the heat absorbing member to sufficiently cool an abnormally heated battery.

[0043] On the other hand, in this embodiment, the container 51 containing the heat-absorbing agent 54 is composed of a laminate 52 including a resin layer 52a and a metal layer 52b, and the periphery of a hole 51D penetrating the laminate 52 is welded by a welded portion 52C. As a result, the heat from the abnormally heated battery 30 causes the welded portion of the resin layer 52a to peel off, and the heat-absorbing agent 54 released from the hole 51D comes into contact with the abnormally heated battery 30, cooling the abnormally heated battery 30. As a result, by providing the welded portion 52C of the resin layer 52a at a desired location on the container 51, the abnormally heated battery 30 can be effectively cooled. Therefore, the abnormally heated battery 30 can be sufficiently cooled by the heat-absorbing member 50.

[0044] In this embodiment, an end wall W3 constituting a part of the end of the container 51 is provided adjacent to both of the arc walls W1 and W2, and the holes 51D are provided at a position spaced apart from the end wall W3. For example, each hole 51D is provided in a central region in the longitudinal direction of the container 51. This eliminates the risk of wrinkles being formed at the end of the container 51 and causing deformation when the holes 51D are formed during the manufacturing process of the heat absorption member 50.

[0045] In this embodiment, the laminate 52 has an acutely bent shape (bent portion) at the boundary between the arc-shaped wall W1 and the arc-shaped wall W2, and the hole 51D is formed in the bent portion. The hole 51D is disposed, for example, near the periphery of both the first battery 30 and the second battery 30. This allows the heat from the abnormally heated battery 30 to peel off the welded portion of the resin layer 52a, and the heat-absorbing agent 54 released from the hole 51D comes into contact with the abnormally heated battery 30, thereby cooling the abnormally heated battery 30. As a result, by providing the welded portion 52C of the resin layer 52a at a desired location on the container 51, the abnormally heated battery 30 can be effectively cooled. Therefore, the abnormally heated battery 30 can be sufficiently cooled by the heat-absorbing member 50.

[0046] In this embodiment, each battery 30 is a cylindrical battery, and a plurality of heat-absorbing members 50 are arranged in a position surrounded by four adjacent batteries 30. As a result, for example, when one battery 30 in the battery pack 1 generates abnormal heat, the heat generated by the abnormally heated battery 30 is absorbed by the heat-absorbing member 50, and the rate at which the heat is transmitted to the batteries 30 adjacent to the abnormally heated battery 30 can be significantly reduced.

[0047] In this embodiment, the heat absorption member 50 has four arc walls W1. This increases the contact area between the heat absorption member 50 and the four batteries 30 arranged around the heat absorption member 50. As a result, the heat generated by a battery 30 that is experiencing abnormal heat generation can be efficiently absorbed by the heat absorption member 50.

[0048] Next, a modification of the battery pack 1 according to the above embodiment will be described.

[0049] (Variation A) In the above embodiment, the laminate 52 may be configured, for example, as shown in FIG. 12 , in which a metal layer 52b is sandwiched between resin layers 52a and 52c. The resin layer 52c is made of a resin material such as polyethylene, polystyrene, polypropylene, or polycarbonate. In this case, the hole 51D penetrates the resin layer 52c. In this case, the metal layer 52b is covered with the resin layer 52c, which can prevent the metal layer 52b from shorting out with conductors in the battery module 20.

[0050] (Modification B) Fig. 13(A) shows a perspective view of a heat-absorbing member 50 according to this modification. Fig. 13(B) shows a cross-sectional view of the heat-absorbing member 50 of Fig. 13(A) taken along line A-A. Fig. 13(C) shows a cross-sectional view of the heat-absorbing member 50 of Fig. 13(A) taken along line B-B.

[0051] In the above-described embodiment and its modified examples, the heat-absorbing member 50 may have a cylindrical laminate 55, as shown in Figures 13(B) and 13(C), for example. The laminate 55 has, for example, arc walls W1 and W2, arc surfaces S1 and S2, arc walls W5 and W6, and arc surfaces S5 and S6. The two arc walls W5 and W6 and the two arc surfaces S5 and S6 have a concave shape conforming to the outer peripheral surface of the battery 30. The arc wall W6 is located adjacent to the arc wall W5. The arc surface S6 is located adjacent to the arc surface S5.

[0052] The laminate 55 corresponds to a specific example of a "first laminate portion" or "second laminate portion" in the present technology. The arc wall W5 corresponds to a specific example of a "fourth laminate portion" in the present technology. The arc wall W6 corresponds to a specific example of a "fifth laminate portion" in the present technology. The heat absorption member 50 further has an end wall W3 arranged adjacent to both the arc walls W1 and W2, and an end wall W3 arranged adjacent to both the arc walls W5 and W6.

[0053] The container 51 is formed, for example, by covering the heat-absorbing agent 54 with a cylindrical laminate 55 and then heating and molding the heat-absorbing agent 54 and the laminate 55. As shown in FIGS. 13(A), 13(B), and 13(C), the container 51 includes a storage section 51A that stores the heat-absorbing agent 54 and a flange section 51B formed around the storage section 51A. The storage section 51A corresponds to the approximately diamond-shaped columnar portion of the container 51 that is formed by the arc-shaped walls W1 and W2, the four end walls W3, and the arc-shaped walls W5 and W6. The flange section 51B corresponds to the plate-shaped portion of the container 51 that surrounds the storage section 51A when viewed from a direction that allows the arc-shaped walls W1 and W2 to be seen as a whole. The container 51 (laminate 55) is configured, for example, to include a resin layer 52a and a metal layer 52b in this order from the heat-absorbing agent 54 side.

[0054] As shown in Fig. 13(B), the laminate 55 has a shape bent at an acute angle at the boundary α between the arcuate wall W1 and the arcuate wall W2. At the boundary α (bent portion) between the arcuate wall W1 and the arcuate wall W2, a portion of the resin layer 52a of the arcuate wall W1 and a portion of the resin layer 52a of the arcuate wall W2 are welded to each other, as shown in Fig. 13(B). At the boundary α (bent portion) between the arcuate wall W1 and the arcuate wall W2, a portion of the resin layer 52a of the arcuate wall W1 and a portion of the resin layer 52a of the arcuate wall W2 are sealed by adhesion, for example. The portion where the portion of the resin layer 52a of the arcuate wall W1 and the portion of the resin layer 52a of the arcuate wall W2 are welded (sealed) to each other is a welded portion 52C in Fig. 13(B).

[0055] 13(B), the laminate 55 has a shape bent at an acute angle at the boundary β between the arc-shaped wall W5 and the arc-shaped wall W6. At the boundary β (bent portion) between the arc-shaped wall W5 and the arc-shaped wall W6, a portion of the resin layer 52a of the arc-shaped wall W5 and a portion of the resin layer 52a of the arc-shaped wall W6 are welded to each other, as shown in FIG. 13(B), for example. The portion where the portion of the resin layer 52a of the arc-shaped wall W5 and the portion of the resin layer 52a of the arc-shaped wall W6 are welded to each other is a welded portion 52F in FIG.

[0056] As shown in Figures 13(A) and 13(C), the laminate 55 has one or more cutouts 51C at the boundary α (folded portion) between the arcuate wall W1 and the arcuate wall W2. The one or more cutouts 51C are disposed adjacent to the circumferential surfaces of both the first battery 30 and the second battery 30. The one or more cutouts 51C are located at a distance from the end wall W3. Each cutout 51C is located in the central region of the container 51 in the longitudinal direction. Here, the "central region" refers to, for example, a region at the boundary α (folded portion) between the two end walls W3, separated from the end wall W3 by a length equal to the height of the end wall W3. As shown in Figure 13(C), a welded portion 52C is exposed on the surface of each cutout 51C. In other words, each cutout 51C penetrates the laminate 55. Therefore, when the welded portion 52C in each cutout 51C melts due to the heat of, for example, an abnormally heated battery 30, the heat-absorbing agent 54 leaks out through each cutout 51C (for example, to the periphery of the abnormally heated battery 30). Therefore, each cutout 51C is provided with a hole 51D penetrating the stack 55.

[0057] The laminate 55 further includes one or more cutouts 51E at the boundary β (folded portion) between the arcuate wall W5 and the arcuate wall W6, as shown in FIG. 13C . The cutouts 51E are disposed adjacent to the circumferential surfaces of both the first battery 30 and the second battery 30. The cutouts 51E are located at a distance from the end wall W3. Each cutout 51E is located in the central region of the longitudinal direction of the container 51. Here, the "central region" refers to, for example, a region at the boundary β (folded portion) between the two end walls W3, separated from the end wall W3 by a length equal to the height of the end wall W3. As shown in FIG. 13C , a welded portion 52F is exposed on the surface of each cutout 51E. In other words, each cutout 51E penetrates the laminate 55. Therefore, when the welded portion 52F in each cutout 51E melts due to the heat of, for example, an abnormally heated battery 30, the heat-absorbing agent 54 leaks out through each cutout 51E (for example, to the periphery of the abnormally heated battery 30). Therefore, each cutout 51E is provided with a hole 51F penetrating the stack 55.

[0058] Next, a method for manufacturing holes 51D and 51F will be described. First, a mountain-shaped laminate 55 is prepared. Next, the ridge of the mountain-shaped portion of laminate 55 is sandwiched between two flat mold pieces, and in this state, each mold piece is heated to a predetermined temperature. As a result, heat from each mold piece is transmitted to resin layer 52a in laminate 55, and a portion of resin layer 52a is welded to form welded portion 52C. Next, one or more notches 51C and 51E are formed in laminate 55 at the locations where welded portion 52C is formed. As a result, hole 51D is formed in notch 51C, and hole 51F is formed in notch 51E. In this manner, holes 51D and 51F are manufactured.

[0059] In this modification, the container 51 containing the heat-absorbing agent 54 is composed of a laminate 52 including a resin layer 52a and a metal layer 52b, and the peripheries of holes 51D and 51F penetrating the laminate 52 are welded with welded portions 52C and 52F. As a result, the heat from the abnormally heated battery 30 causes the welded portions of the resin layer 52a to peel off, and the heat-absorbing agent 54 released from the holes 51D and 51F comes into contact with the abnormally heated battery 30, thereby cooling the abnormally heated battery 30. As a result, by providing the welded portions 52C and 52F of the resin layer 52a at desired locations on the container 51, the abnormally heated battery 30 can be effectively cooled. Therefore, the abnormally heated battery 30 can be sufficiently cooled by the heat-absorbing member 50.

[0060] In this modification, the laminate 55 has an acutely bent shape (bent portion) formed at the boundary α between the arc-shaped wall W1 and the arc-shaped wall W2, and the hole 51D is formed in the bent portion. The hole 51D is disposed, for example, near the circumferential surface of both the first battery 30 and the second battery 30. This causes the heat from the abnormally heated battery 30 to peel off the welded portion of the resin layer 52a, and the heat-absorbing agent 54 released from the hole 51D comes into contact with the abnormally heated battery 30, thereby cooling the abnormally heated battery 30. Therefore, by providing the welded portion 52C of the resin layer 52a at a desired location on the container 51, the abnormally heated battery 30 can be effectively cooled.

[0061] In this modification, the laminate 55 further includes an acutely bent shape (bent portion) at the boundary β between the arc-shaped wall W5 and the arc-shaped wall W6, and the hole 51F is formed in the bent portion. The hole 51F is disposed, for example, near the periphery of both the first battery 30 and the second battery 30. This causes the heat from the abnormally heated battery 30 to peel off the welded portion of the resin layer 52a, and the heat-absorbing agent 54 released from the hole 51F comes into contact with the abnormally heated battery 30, thereby cooling the abnormally heated battery 30. Therefore, by providing the welded portion 52F of the resin layer 52a at a desired location on the container 51, the abnormally heated battery 30 can be effectively cooled.

[0062] In this modified example, an end wall W3 constituting a part of the end of the container 51 is provided adjacent to both of the arc walls W1 and W2, and the holes 51D are provided at a position spaced apart from the end wall W3. For example, each hole 51D is provided in a central region in the longitudinal direction of the container 51. In this modified example, an end wall W3 constituting a part of the end of the container 51 is provided adjacent to both of the arc walls W5 and W6, and the holes 51F are provided at a position spaced apart from the end wall W3. For example, each hole 51F is provided in a central region in the longitudinal direction of the container 51. This prevents wrinkles from forming at the end of the container 51 and causing deformation when the holes 51D and 51F are formed during the manufacturing process of the heat absorption member 50.

[0063] In this modification, the laminate 55 may have a configuration in which the metal layer 52b is sandwiched between the resin layers 52a and 52c. In this case, the holes 51D and 51F penetrate the resin layer 52c. In this case, the metal layer 52b is covered with the resin layer 52c, which more reliably prevents the metal layer 52b from shorting out with the conductors in the battery module 20.

[0064] (Variation C) In the above-described embodiment and variations thereof, a battery module 200 as shown in Fig. 14 and Fig. 15 may be provided instead of the battery module 20. Fig. 14 shows an example of a perspective configuration of the battery module 200. Fig. 15 shows an example of an exploded perspective configuration of the battery module 200. The battery module 200 includes, for example, a plurality of batteries 210 and a plurality of heat absorption members 220 as shown in Fig. 14 and Fig. 15.

[0065] The multiple batteries 210 are stacked in the thickness direction of the batteries 210. The thickness direction of the batteries 210 refers to the direction in which the top and bottom surfaces of the batteries 210 face each other. The top surface of the battery 210 refers to the top surface of the battery 210 when the battery module 200 is housed in the exterior case 10. The bottom surface of the battery 210 refers to the bottom surface of the battery 210 when the battery module 200 is housed in the exterior case 10. The multiple heat absorption members 220 are stacked in the same direction as the stacking direction of the multiple batteries 210. The multiple batteries 210 and the multiple heat absorption members 220 are arranged alternately in the stacking direction of the multiple batteries 210. One heat absorption member 220 is provided between two adjacent batteries 210. The heat absorption member 220 is in contact with each of the two batteries 210 arranged above and below the heat absorption member 220.

[0066] The plurality of batteries 210 are electrically connected via a plurality of metal tabs. The batteries 210 are flat, laminated film type batteries. For example, the batteries 210 have positive and negative electrodes on their side surfaces. In the battery module 200, for example, some of the plurality of batteries 210 are connected in series with each other via a plurality of metal tabs. Furthermore, when the plurality of batteries 210 connected in series with each other are referred to as a series unit, the plurality of series units are connected in parallel with each other via a plurality of metal tabs. Note that the connection of the plurality of batteries 210 is not limited to the above.

[0067] Each battery 210 is a primary battery or a secondary battery. When each battery 210 is a secondary battery, the type of secondary battery is not particularly limited, but specifically, it may be a lithium-ion secondary battery that obtains battery capacity by utilizing the absorption and release of lithium ions. The following describes a case where each battery 210 is a secondary battery (lithium-ion secondary battery). In other words, the battery pack 1 described below is a power source including multiple secondary batteries.

[0068] Fig. 16 shows an example of a perspective configuration of the heat absorption member 220. Fig. 17 shows an example of a cross-sectional configuration of the heat absorption member 220 taken along line A-A. The heat absorption member 220 has a flat plate shape, for example, as shown in Fig. 16. The heat absorption member 220 has a heat absorption agent 54 and a container 230 that covers the heat absorption agent 54, for example, as shown in Fig. 17.

[0069] 17 , the container 230 has a first surface Sa disposed adjacent to the first battery 210 and a second surface Sb facing the first surface Sa with the heat-absorbing agent 54 interposed therebetween. The second surface Sb is disposed adjacent to the second battery 210 adjacent to the first battery 210. As shown in FIG. 17 , the container 230 has one or more through holes 240 penetrating the first surface Sa and the second surface Sb. The periphery of each through hole 240 is sealed by a portion of the first surface Sa surrounding the through hole 240 and a portion of the second surface Sb surrounding the through hole 240.

[0070] 17 , the container 230 has a stack 56 having a first surface Sa and a stack 57 having a second surface Sb. Each of the stacks 56 and 57 includes a resin layer 52 a and a metal layer 52 b, in this order from the heat-absorbing agent 54 side. Each through-hole 240 penetrates the first surface Sa and the second surface Sb, and penetrates both the stack 56 and the stack 57.

[0071] The periphery of through hole 240 is sealed by the portion of first surface Sa surrounding through hole 240 and the portion of second surface Sb surrounding through hole 240. The periphery of through hole 240 is sealed by the portion of resin layer 52a of laminate 56 surrounding through hole 240 and the portion of resin layer 52a of laminate 57 surrounding through hole 240. In FIG. 17 , the portion where the portion of resin layer 52a of laminate 56 surrounding through hole 240 and the portion of resin layer 52a of laminate 57 surrounding through hole 240 are welded (sealed) to each other is welded portion 52G.

[0072] A welded portion 52G is exposed at the end face (inner surface) of each through hole 240. Therefore, when the welded portion 52G in each through hole 240 melts due to the heat of, for example, an abnormally heated battery 30, the heat-absorbing agent 54 is released to the outside (for example, the periphery of the abnormally heated battery 30) through each through hole 240. Therefore, a discharge portion 51G penetrating the end face (inner surface) of each through hole 240 is provided at the end face (inner surface) of each through hole 240. For example, as shown in FIG. 17 , the periphery of the discharge portion 51G is welded by a welded portion 52G. Furthermore, for example, as shown in FIG. 17 , the discharge portion 51G is welded by a welded portion 52G.

[0073] 17, the welded portion 52G and the discharge portion 51G are provided at a location closer to the first surface Sa than to the second surface Sb. In other words, the welded portion 52G and the discharge portion 51G are provided at a location closer to the battery 2220 provided on the first surface Sa side than to the battery 220 provided on the second surface Sb side.

[0074] In this modification, the container 230 has a first surface Sa, a second surface Sb, and one or more through holes 240. The periphery of each through hole 240 is sealed (welded) by the portion of the first surface Sa surrounding the through hole 230 and the portion of the second surface Sb surrounding the through hole 240. As a result, the heat from the abnormally heated battery 30 causes the welded portion 52G to peel off, and the heat-absorbing agent 54 released from the welded portion 52G comes into contact with the abnormally heated battery 30, thereby cooling the abnormally heated battery 30. As a result, by providing the through holes 240 and the welded portion 52G at desired locations on the container 230, the abnormally heated battery 30 can be effectively cooled. Therefore, the abnormally heated battery 30 can be sufficiently cooled by the heat-absorbing member 50.

[0075] In this modification, the periphery of each through-hole 240 is sealed (welded) by the portion of the resin layer 52a of the laminate 56 surrounding the through-hole 240 and the portion of the resin layer 52a of the laminate 57 surrounding the through-hole 240. As a result, the heat from the abnormally heated battery 30 causes the welded portion 52G to peel off, and the heat-absorbing agent 54 released from the welded portion 52G comes into contact with the abnormally heated battery 30, cooling the abnormally heated battery 30. As a result, by providing the through-holes 240 and the welded portion 52G at desired locations on the container 230, the abnormally heated battery 30 can be effectively cooled. Therefore, the abnormally heated battery 30 can be sufficiently cooled by the heat-absorbing member 50.

[0076] 18 , for example, the container 230 may be provided with a through-hole 240 in which a welded portion 52G and a discharge portion 51G are provided at a position closer to the first surface Sa than to the second surface Sb, and a through-hole 240 in which a welded portion 52G and a discharge portion 51G are provided at a position closer to the second surface Sb than to the first surface Sa. That is, in the present modification, the container 230 may be provided with a through-hole 240 in which a welded portion 52G and a discharge portion 51G are provided at a position closer to the battery 220 provided on the first surface Sa side than to the battery 220 provided on the second surface Sb side, and a through-hole 240 in which a welded portion 52G and a discharge portion 51G are provided at a position closer to the battery 220 provided on the second surface Sb side than to the battery 220 provided on the first surface Sa side. In this case, if either the battery 220 on the first surface Sa side or the battery 220 on the second surface Sb side abnormally heats up, the welded portion 52G provided near the abnormally heated battery 220 will peel off due to the heat of the abnormally heated battery 30, and the heat-absorbing agent 54 released from the welded portion 52G will come into contact with the abnormally heated battery 30, cooling the abnormally heated battery 30. As a result, by providing the through-holes 240 and the welded portions 52G in desired locations on the container 230, the abnormally heated battery 30 can be effectively cooled. Therefore, the abnormally heated battery 30 can be sufficiently cooled by the heat-absorbing member 50.

[0077] In this modification, the laminate 55 may have a configuration in which the metal layer 52b is sandwiched between the resin layers 52a and 52c, as shown in Figures 19 and 20. In this case, the holes 51D and 51F penetrate the resin layer 52c. In this case, the metal layer 52b is covered with the resin layer 52c, which can prevent the metal layer 52b from shorting out with the conductors in the battery module 20.

[0078] The present technology has been described above by giving embodiments and their modified examples, but the present technology is not limited to the aspects described in the above embodiments and their modified examples, and various modifications are possible with respect to the present technology.

[0079] For example, in the above-described embodiment and its modified examples, lithium is used as the electrode reactant of the secondary battery, but the type of the electrode reactant is not particularly limited. Specifically, the electrode reactant may be other Group 1 elements in the long periodic table, such as sodium and potassium, or Group 2 elements in the long periodic table, such as magnesium and calcium, or other light metals, such as aluminum.

[0080] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0081] The present technology may also be configured as follows: <1> A battery pack including: a battery; and a heat-absorbing member having a heat-absorbing agent and a container that accommodates the heat-absorbing agent, wherein the heat-absorbing member is disposed adjacent to the battery, and the container has a first laminate including a first resin layer and a first metal layer in this order from the heat-absorbing agent side, and the first laminate has a first hole that penetrates the first resin layer and the first metal layer, and the periphery of the first hole is sealed with the first resin layer that surrounds the first hole. <2> The battery pack according to <1>, wherein the battery is a cylindrical battery, a plurality of the batteries are arranged side by side, the container has a columnar shape extending in the longitudinal direction of the batteries, the first stack has a first stack portion along the circumferential surface of the first battery, and a second stack portion arranged adjacent to the first stack portion and along the circumferential surface of a second battery adjacent to the first battery, the first stack has the first hole at the boundary between the first stack portion and the second stack portion, and the periphery of the first hole is sealed by adhesion between the first resin layer of the first stack portion and the first resin layer of the second stack portion. <3> The battery pack according to <2>, wherein the first laminate further includes a third laminate portion disposed adjacent to both the first laminate portion and the second laminate portion and constituting a part of an end portion of the container, and the first hole is provided at the boundary at a position spaced apart from the third laminate portion. <4> The battery pack according to <3>, wherein the first hole is provided in a central region in the longitudinal direction of the container. <5> The battery pack according to any one of <2> to <4>, wherein the first laminate has a shape bent at an acute angle at the boundary, and the first hole is provided close to the peripheral surfaces of both the first battery and the second battery. <6> The battery pack according to <2>, wherein the container has a second laminate including a second resin layer and a second metal layer in this order from the heat-absorbing agent side, the second laminate has a second hole penetrating the second resin layer and the second metal layer, and the periphery of the second hole is sealed by the second resin layer surrounding the second hole.<7> The battery pack according to <6>, wherein the second laminate has a fourth laminate portion along the circumferential surface of the third battery, and a fifth laminate portion arranged adjacent to the fourth laminate portion and along the circumferential surface of the fourth battery adjacent to the third battery, the second laminate has the second hole at the boundary between the fourth laminate portion and the fifth laminate portion, and the periphery of the second hole is sealed by adhesion between the second resin layer of the fourth laminate portion and the second resin layer of the fifth laminate portion. <8> The battery pack according to <7>, wherein the second laminate has a shape bent at an acute angle at the boundary between the fourth laminate portion and the fifth laminate portion, and the second hole is arranged adjacent to the circumferential surfaces of both the third battery and the fourth battery. <9> The battery pack according to any one of <2> to <8>, wherein the first laminate includes a third resin layer on the outside of the first metal layer that covers the first metal layer, and the first hole also penetrates the third resin layer. <10> The battery pack according to any one of <6> to <9>, wherein the second laminate includes a fourth resin layer on the outside of the second metal layer that covers the second metal layer, and the second hole also penetrates the fourth resin layer. <11> A battery pack comprising: a first battery; and a heat-absorbing member having a heat-absorbing agent and a container that accommodates the heat-absorbing agent, wherein the first battery and the container are both flat-plate shaped; the container has: a first surface disposed adjacent to the first battery; a second surface facing the first surface with the heat-absorbing agent interposed therebetween; and a first through hole that penetrates the first surface and the second surface, wherein a periphery of the first through hole is sealed by a portion of the first surface that surrounds the first through hole and a portion of the second surface that surrounds the first through hole.<12> The battery pack according to <11>, wherein the container has: a first laminate having the first surface; and a second laminate having the second surface; the first laminate includes a first resin layer and a first metal layer in this order from the heat-absorbing agent side; the second laminate includes a second resin layer and a second metal layer in this order from the heat-absorbing agent side; the first through hole penetrates both the first laminate and the second laminate; and the periphery of the first through hole is sealed by a portion of the first resin layer surrounding the first through hole and a portion of the second resin layer surrounding the first through hole. <13> The battery pack according to <11>, further including a flat-plate-shaped second battery, wherein the second surface is disposed adjacent to the second battery, and the container further has a second through-hole penetrating the first surface and the second surface, a periphery of the second through-hole is sealed by a portion of the first surface surrounding the second through-hole and a portion of the second surface surrounding the second through-hole, a portion of the periphery of the first through-hole sealed by the portion of the first surface surrounding the first through-hole and the portion of the second resin layer surrounding the first through-hole is provided closer to the first battery than the second battery, and a portion of the periphery of the second through-hole sealed by the portion of the first resin layer surrounding the second through-hole and the portion of the second resin layer surrounding the second through-hole is provided closer to the second battery than the first battery.<14> The container has: a first laminate having the first surface; and a second laminate having the second surface, wherein the first laminate includes a first resin layer and a first metal layer in this order from the heat-absorbing agent side; the second laminate includes a second resin layer and a second metal layer in this order from the heat-absorbing agent side; the first through-hole penetrates both the first laminate and the second laminate; the second through-hole penetrates both the first laminate and the second laminate; a portion around the first through-hole that is sealed by a portion of the first resin layer surrounding the first through-hole and a portion of the second resin layer surrounding the first through-hole is provided at a location closer to the first battery than the second battery; The battery pack according to <13>, wherein a portion around the second through hole that is sealed by the portion of the first resin layer surrounding the second through hole and the portion of the second resin layer surrounding the second through hole is located closer to the second battery than to the first battery.

Claims

1. A battery pack comprising: a battery; and a heat absorbing member having a heat absorbing agent and a container for accommodating the heat absorbing agent, wherein the heat absorbing member is disposed in a position adjacent to the battery, and the container has a first laminate including a first resin layer and a first metal layer in this order from the heat absorbing agent side, and the first laminate has a first hole penetrating the first resin layer and the first metal layer, and the periphery of the first hole is sealed by the first resin layer surrounding the first hole.

2. The battery pack according to claim 1, wherein the battery is a cylindrical battery, a plurality of the batteries are arranged side by side, the container is in a columnar shape extending in the longitudinal direction of the batteries, the first laminate has a first laminate portion along the circumferential surface of the first battery, and a second laminate portion arranged adjacent to the first laminate portion and along the circumferential surface of a second battery adjacent to the first battery, the first laminate has the first hole at the boundary between the first laminate portion and the second laminate portion, and the periphery of the first hole is sealed by adhesion between the first resin layer of the first laminate portion and the first resin layer of the second laminate portion.

3. The battery pack according to claim 2, wherein the first laminate further has a third laminate portion that is disposed adjacent to both the first laminate portion and the second laminate portion and that constitutes a part of the end portion of the container, and the first hole is provided at a position at the boundary spaced apart from the third laminate portion.

4. The battery pack according to claim 3, wherein the first hole is provided in a central region in the longitudinal direction of the container.

5. A battery pack as claimed in any one of claims 2 to 4, wherein the first laminate is bent at an acute angle at the boundary, and the first hole is disposed adjacent to the peripheral surfaces of both the first battery and the second battery.

6. A battery pack as described in claim 2, wherein the container has a second laminate including a second resin layer and a second metal layer in this order from the heat-absorbing agent side, the second laminate has a second hole penetrating the second resin layer and the second metal layer, and the periphery of the second hole is sealed by the second resin layer surrounding the second hole.

7. The battery pack described in claim 6, wherein the second laminate has a fourth laminate portion that runs along the peripheral surface of the third battery, and a fifth laminate portion that is arranged adjacent to the fourth laminate portion and runs along the peripheral surface of the fourth battery adjacent to the third battery, the second laminate has the second hole at the boundary between the fourth laminate portion and the fifth laminate portion, and the periphery of the second hole is sealed by adhesion between the second resin layer of the fourth laminate portion and the second resin layer of the fifth laminate portion.

8. A battery pack as described in claim 7, wherein the second laminate is bent at an acute angle at the boundary between the fourth laminate portion and the fifth laminate portion, and the second hole is disposed adjacent to the peripheral surfaces of both the third battery and the fourth battery.

9. A battery pack as described in any one of claims 2 to 8, wherein the first laminate includes a third resin layer covering the first metal layer on the outside of the first metal layer, and the first hole also penetrates the third resin layer.

10. A battery pack as described in any one of claims 6 to 9, wherein the second laminate includes a fourth resin layer covering the second metal layer on the outside of the second metal layer, and the second hole also penetrates the fourth resin layer.

11. A battery pack comprising: a first battery; and a heat absorbing member having a heat absorbing agent and a container for accommodating the heat absorbing agent, wherein the first battery and container are both flat in shape, and the container has a first surface disposed adjacent to the first battery, a second surface facing the first surface with the heat absorbing agent interposed therebetween, and a first through hole penetrating the first surface and the second surface, and the periphery of the first through hole is sealed by a portion of the first surface surrounding the first through hole and a portion of the second surface surrounding the first through hole.

12. The battery pack described in claim 11, wherein the container has a first laminate having the first surface and a second laminate having the second surface, the first laminate including a first resin layer and a first metal layer in this order from the heat absorbing agent side, the second laminate including a second resin layer and a second metal layer in this order from the heat absorbing agent side, the first through hole penetrates both the first laminate and the second laminate, and the periphery of the first through hole is sealed by a portion of the first resin layer surrounding the first through hole and a portion of the second resin layer surrounding the first through hole.

13. The battery pack according to claim 11, further comprising a flat-plate shaped second battery, the second surface being arranged adjacent to the second battery, the container further having a second through hole penetrating the first surface and the second surface, the periphery of the second through hole being sealed by the portion of the first surface surrounding the second through hole and the portion of the second surface surrounding the second through hole, a portion of the periphery of the first through hole sealed by the portion of the first surface surrounding the first through hole and the portion of the second resin layer surrounding the first through hole is provided at a location closer to the first battery than the second battery, and a portion of the periphery of the second through hole sealed by the portion of the first resin layer surrounding the second through hole and the portion of the second resin layer surrounding the second through hole is provided at a location closer to the second battery than the first battery.

14. The container has a first laminate having the first surface and a second laminate having the second surface, the first laminate including a first resin layer and a first metal layer in this order from the heat absorbing agent side, the second laminate including a second resin layer and a second metal layer in this order from the heat absorbing agent side, the first through hole penetrates both the first laminate and the second laminate, the second through hole penetrates both the first laminate and the second laminate, a portion around the first through hole that is sealed by a portion of the first resin layer surrounding the first through hole and a portion of the second resin layer surrounding the first through hole is provided at a location closer to the first battery than the second battery, 14. The battery pack of claim 13, wherein a portion around the second through hole that is sealed by the portion of the first resin layer surrounding the second through hole and the portion of the second resin layer surrounding the second through hole is located closer to the second battery than to the first battery.

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