Battery pack

Abstract

Provided is a battery pack which has achieved further mechanical strength of an accommodation body for accommodating a heat absorbing agent and which has achieved further reduction in deformation of the accommodation body when accommodating therein the heat absorbing agent and deformation of the accommodation body due to vibration and impact during normal use of the battery pack. A battery pack 1 according to the present disclosure comprises: a plurality of batteries 10; and a heat absorbing member 20 that includes a heat absorbing agent 21 and an accommodation body 22 for accommodating the heat absorbing agent 21. The heat absorbing member 20 is disposed at a position adjacent to the batteries 10. The accommodation body 22 has a plurality of accommodation portions AP that are each formed in a triangular prism shape and accommodate the heat absorbing agent 21 therein. Vertex portions PP of the triangular prism-shaped accommodation portions AP are arranged at positions adjacent to each other. Two surfaces constituting each of the vertex portions PP are not adjacent to the batteries 10.

Description

Battery pack

[0001] The present disclosure relates to a battery pack.

[0002] Patent Document 1 discloses a battery pack comprising a plurality of batteries, upper and lower partition plates arranged between the plurality of batteries to separate the plurality of batteries from one another, and a heat-absorbing agent housed inside the upper and lower partition plates to cool the plurality of batteries, with the heat-absorbing agent cooling the plurality of batteries being housed in the storage space of the upper partition plate and the storage space of the lower partition plate.

[0003] According to the battery pack disclosed in Patent Document 1, when an abnormality occurs due to heat generation in the battery, the battery, which is the heat source, can be cooled by the heat-absorbing agent.

[0004] International Publication No. 2023 / 047741

[0005] The battery pack disclosed in Patent Document 1 does not have a support or the like in the storage space that stores the heat-absorbing agent, and there is room for improvement in the mechanical strength of the storage space.

[0006] The present disclosure has been made in light of this viewpoint. That is, a main object of the present disclosure is to provide a battery pack in which the mechanical strength of a housing that houses an endothermic agent is further improved, and in which deformation of the housing when housing the endothermic agent in the housing and deformation of the housing due to vibrations and impacts during normal use of the battery pack are further reduced.

[0007] The battery pack of the present disclosure comprises a plurality of batteries and a heat-absorbing member having a heat-absorbing agent and a housing that houses the heat-absorbing agent, the heat-absorbing member being positioned adjacent to the batteries, the housing being triangular prism-shaped and having a plurality of housing sections that house the heat-absorbing agent, the vertices of the triangular prism-shaped housing sections being positioned adjacent to each other, and the two faces that make up the vertices not being adjacent to the batteries.

[0008] The battery pack of the present disclosure also includes: a plurality of batteries; and a plurality of heat-absorbing members each having a heat-absorbing agent and a housing that houses the heat-absorbing agent; each of the plurality of heat-absorbing members is arranged adjacent to one of the plurality of batteries; each of the plurality of housings is triangular prism-shaped and is arranged such that one vertex of one of the triangular prism-shaped housings is adjacent to one vertex of another of the triangular prism-shaped housings; the two faces that make up the vertex are not adjacent to a battery; and adjacent heat-absorbing members are in contact with each other.

[0009] According to the present disclosure, it is possible to provide a battery pack in which the mechanical strength of the housing that houses the heat-absorbing agent is further improved, and deformation of the housing when housing the heat-absorbing agent in the housing, and deformation of the housing due to vibrations and impacts during normal use of the battery pack are further reduced.

[0010] FIG. 1 is a schematic exploded perspective view of a battery pack. FIG. 2 is a schematic exploded perspective view of a core pack housed in the battery pack. FIG. 3 is a schematic exploded perspective view of a heat-absorbing member of a first embodiment. FIG. 4 is a schematic perspective view of the heat-absorbing member of the first embodiment. FIG. 5 is a schematic cross-sectional view of the heat-absorbing member of the first embodiment. FIG. 6 is a schematic explanatory view illustrating a state in which the heat-absorbing member of the first embodiment is folded. FIG. 7 is a schematic cross-sectional view of a main part of a battery pack of the present disclosure. FIG. 8 is a schematic cross-sectional view of a main part when an abnormality occurs in the battery pack. FIG. 9 is a schematic cross-sectional view of a main part of a conventional battery pack. FIG. 10 is a schematic exploded perspective view of a heat-absorbing member of a second embodiment. FIG. 11 is a schematic perspective view of a heat-absorbing member of the second embodiment.

[0011] A battery pack according to an embodiment of the present disclosure will be described in more detail below. While the description will be made with reference to drawings as needed, the various elements in the drawings are merely shown schematically and for illustrative purposes to facilitate understanding of the present disclosure, and the appearance and dimensional ratios may differ from those of the actual product.

[0012] As used herein, the term "plan view" refers to the state when an object (e.g., a battery pack) is placed and viewed from directly above in the thickness (height) direction, and is synonymous with a plan view. For example, the term "plan view" refers to the state when viewed along the positive direction in the "third direction" shown in FIG. 1 . As used herein, unless otherwise specified, the term "side view" refers to the state when an object (e.g., a battery pack) is placed and viewed from the side perpendicular to the thickness (height) direction, and is synonymous with a side view. For example, the term "side view" refers to the state when viewed along the positive (or negative) direction in the "first direction" shown in FIG. 1 . As used herein, the term "front view" refers to the state when an object (e.g., a battery pack) is placed and viewed from the front perpendicular to the thickness (height) direction, and is synonymous with a front view. For example, the term "front view" refers to the state when viewed along the positive direction in the "second direction" shown in FIG. 1 . The "positive direction" refers to the direction of the first, second, and third arrows shown in the drawings, and the "negative direction" refers to the direction opposite to the direction of the first, second, and third arrows shown in the drawings. The first, second, and third directions are perpendicular to each other. The terms "about" and "approximately" used in this specification mean that the values ​​may vary by a few percent, for example, ±10%.

[0013] [Battery Pack] A battery pack 1 according to the present disclosure will be described with reference to Figures 1 to 9. Figure 1 is a schematic exploded perspective view of the battery pack 1, Figure 2 is a schematic exploded perspective view of a core pack CP housed in the battery pack 1, Figure 3 is a schematic exploded perspective view of a heat-absorbing member 20 according to a first embodiment, Figure 4 is a schematic perspective view of the heat-absorbing member 20 according to the first embodiment, Figure 5 is a schematic cross-sectional view of the heat-absorbing member 20 according to the first embodiment, Figure 6 is a schematic explanatory diagram illustrating the heat-absorbing member 20 according to the first embodiment folded up, Figure 7 is a schematic cross-sectional view of a main part of the battery pack 1 according to the present disclosure, Figure 8 is a schematic cross-sectional view of a main part when an abnormality occurs in the battery pack, and Figure 9 is a schematic cross-sectional view of a main part of a conventional battery pack.

[0014] The battery pack 1 may include a case CS and a core pack CP housed in the case CS (see FIGS. 1 and 2).

[0015] The case CS may be composed of a first case CS1 and a second case CS2. The first case CS1 and the second case CS2 may form a storage space for storing the core pack CP. While the example in Fig. 1 illustrates a configuration in which the storage space is formed by two cases (the first case CS1 and the second case CS2), the configuration is not limited to this, and the storage space may be formed by three or more cases.

[0016] The case CS may be made of any material, including resin (e.g., plastic) or metal. Examples of resin materials include polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polybutylene terephthalate (PBT), modified polyphenylene ether (m-PPE), and polyamide (PA). Examples of metal materials include aluminum. To more appropriately accommodate the core pack CP, a highly rigid material may be used for the case CS.

[0017] The case CS may be provided with a connector CN that is electrically connected to the core pack CP. In the example shown in Fig. 1, the connector CN is provided on the second case CS2, but the connector CN may also be provided on the first case CS1. The connector CN may be a terminal for extracting power from the core pack CP.

[0018] 2, the core pack CP may include a plurality of batteries 10, a heat absorption member 20, a battery holder HD that holds and / or fixes the batteries 10 and the heat absorption member 20 within the case CS, tabs TB that are electrically connected to the positive or negative electrodes of the batteries 10, and a control board SB. Details of the batteries 10 and the heat absorption member 20 will be described later in the section on the configuration of the "Main parts of the battery pack."

[0019] The battery holder HD may be a member that holds and / or fixes the battery 10 and heat absorption member 20 within the storage space. In the example shown in Figure 2, the battery holder HD is provided on both the positive and negative sides of the battery 10 in the second direction. In other words, the battery holder HD holds and / or fixes the core pack CP by fitting into the battery 10 and heat absorption member 20 so as to sandwich them from both sides (positive and negative directions) in the second direction.

[0020] 2, the battery holder HD may be provided with an opening OP that exposes the positive and negative terminals of the battery 10. The battery 10 (positive and negative terminals) may be electrically connected to the tabs TB through the opening OP.

[0021] A pair of tabs TB may be provided corresponding to the positive and negative terminals of the battery 10. The control board SB can be driven by supplying power from the battery 10 to the control board SB via the tabs TB.

[0022] [Configuration of Main Parts of Battery Pack of First Embodiment] Next, the main parts (battery 10 and heat-absorbing member 20) of the battery pack 1 of the first embodiment will be described in detail.

[0023] <Battery> The battery 10 is intended to be a chemical battery that converts mainly chemical energy into direct current power through a chemical reaction. The battery 10 used in the battery pack 1 of this embodiment is intended to be a cylindrical battery. Note that the shape of the battery may be a shape other than a cylindrical shape (for example, an elliptical cylinder, a rectangular column, a polygonal column, etc.).

[0024] The battery pack 1 of this embodiment may include two or more batteries 10. The batteries 10 may be arranged adjacent to each other. For example, in the embodiment shown in Fig. 7, four batteries 10 are arranged adjacent to each other.

[0025] <Heat-Absorbing Member> The heat-absorbing member 20 includes a heat-absorbing agent 21 and a container 22 that accommodates the heat-absorbing agent 21 (see FIGS. 3 and 5). The heat-absorbing member 20 is provided adjacent to the battery 10 (see FIG. 7).

[0026] - Heat-absorbing agent - The heat-absorbing agent 21 absorbs heat from the battery when the battery generates abnormal heat. As an example, the heat-absorbing agent 21 is mainly composed of a liquid such as water, and may contain a gelling agent such as sodium polyacrylate and / or a surfactant antifreeze agent.

[0027] - Container - The container 22 is a member that contains the heat-absorbing agent 21. As an example, as shown in Fig. 3, the container 22 may include a first member 22a1 that defines the container portion AP, and a second member 22a2 that is bonded to the first member 22a1 to seal the container portion AP.

[0028] First Member The first member 22a1 may be provided with a plurality of storage portions AP that store the heat-absorbing agent 21. In the example shown in FIG. 3, four storage portions AP are provided. Before storing the heat-absorbing agent 21, each storage portion AP has a hollow triangular prism shape, with one corner of the triangular prism being configured as a vertex PP. In other words, one vertex PP is provided for each storage portion AP, and in the example shown in FIG. 3, four vertices PP are provided corresponding to the four storage portions AP.

[0029] The term "triangular prism shape" as used herein is not limited to a triangular prism shape in the strict sense, but may be intended to include an approximately triangular prism shape having a configuration equivalent to three faces of a triangular prism, two main faces intersecting the three faces, or three corners. For example, it may include cases where the three vertex angles protrude from the faces, where the three corners are rounded or flat, or where the three faces are curved and / or bent. Furthermore, the "vertex portion" may also be protruding, rounded, or flat.

[0030] The vertex PP may be formed by a surface including two sides that form a triangle when the triangular prism shape is viewed in cross section. The vertex PP may extend along the positive second direction shown in FIG. 3 . The storage portion AP having such a vertex PP may be formed by pressing the first member 22a1. Note that, instead of forming the vertex PP by pressing one first member 22a1, a method of forming the vertex PP by bonding two first members 22a1 together and then pressing them may be adopted. Furthermore, the vertex PP may be formed by vacuum forming, pressure forming, or the like, in addition to pressing.

[0031] Adhesive portions AD may be provided around the periphery of the housing portion AP as adhesive areas for bonding to the second member 22a2 (see FIGS. 3 and 5). By adhering the adhesive portions AD to the second member 22a2, the housing portion AP can be sealed. The adhesive portions AD and the second member 22a2 may be bonded by, for example, heat welding or ultrasonic welding. Therefore, the first member 22a1 may be made of a heat-weldable material. Specifically, the first member 22a1 may be made of cold polypropylene (CPP), biaxially oriented polypropylene (OPP), linear low-density polyethylene (LLDPE), or biaxially oriented nylon (ONy). In particular, using cold polypropylene (CPP), biaxially oriented polypropylene (OPP), or linear low-density polyethylene (LLDPE) as the material for the first member 22a1 can improve the chemical resistance of the first member. This can extend the life of the heat-absorbing member.

[0032] In a preferred embodiment of the first member 22a1, the outer surface of the first member 22a1 (i.e., the surface not facing the second member 22a2) may have a metal layer (not shown). Specific examples of the metal layer include aluminum foil, copper foil, and stainless steel foil. By providing a metal layer on the outer surface of the first member 22a1, it is possible to make it difficult for moisture from the heat-absorbing agent contained in the container to permeate and / or evaporate through the container. In a more preferred embodiment, a resin layer may be provided on the outer surface of the metal layer. Examples of materials for the resin layer provided on the outer surface of the metal layer include polyethylene terephthalate (PET), unstretched polypropylene (CPP), biaxially oriented polypropylene (OPP), linear low-density polyethylene (LLDPE), and biaxially oriented nylon (ONy). In a more preferred embodiment, a resin / metal / resin laminate structure may be used. Examples of laminate structures include "PET / aluminum (Al) / polyethylene (PE)," "nylon (Ny) / Al / PE," and / or "PET / Al / Ny / CPP." In the above-described laminate structures, the left side indicates the outer surface of the housing 22, and the right side indicates the inner surface of the housing 22. The material of the resin layer provided on the outer surface of the metal layer may be the same as or different from the material of the first member 22a1. In particular, using polyethylene terephthalate (PET) or polyamide (PA) as the material of the resin layer provided on the outer surface of the metal layer improves the weather resistance and impact resistance of the first member, thereby improving the weather resistance and impact resistance of the entire heat-absorbing member.

[0033] As another example of the first member 22a1, a plurality of holes H may be provided along the longitudinal direction of the housing body 22 at positions between one housing portion AP and another housing portion AP among the plurality of housing portions AP (see FIG. 3). Note that the "plurality of holes H" referred to in this specification do not need to be strictly arranged on a straight line along the longitudinal direction of the housing body 22 (the second direction in FIG. 3), but may be arranged offset in the positive or negative direction of the first direction in FIG. 3. The plurality of holes H may be perforated. By providing the plurality of holes H, when an abnormality occurs in the battery 10, heat-absorbing agent can be released from the holes toward the abnormal battery. Details of what happens when an abnormal battery occurs will be described later.

[0034] The holes H may be provided at positions between one of the plurality of storage portions AP and another of the plurality of storage portions AP, at positions where the first member 22a1 and the second member 22a2 are bonded together (see FIGS. 3 and 5). By providing the holes H at such positions, as will be described in detail below, in the event of an abnormal battery, the adhesion between the first member 22a1 and the second member 22a2 is separated, allowing the heat-absorbing agent to be effectively released from the holes.

[0035] Second Member The second member 22a2 is a member that seals the storage portion AP in the first member 22a1. The second member 22a2 may be made of a material that can be heat-sealed to the first member 22a1. The second member 22a2 may be made of the same heat-sealable material as the first member 22a1, or a different heat-sealable material from the first member 22a1. A metal layer (not shown) may be provided on the outer surface of the second member 22a2 (i.e., the surface that does not face the first member 22a1) to reduce evaporation of moisture from the heat-absorbing agent. In a preferred embodiment, a resin layer may be provided on the outer surface of the metal layer. Examples of materials for the resin layer provided on the outer surface of the metal layer include polyethylene terephthalate (PET), unstretched polypropylene (CPP), biaxially oriented polypropylene (OPP), linear low-density polyethylene (LLDPE), and biaxially oriented nylon (ONy). Furthermore, a preferred embodiment may be a resin / metal / resin laminate structure. Examples of laminate structures include "PET / aluminum (Al) / polyethylene (PE)," "nylon (Ny) / Al / PE," and / or "PET / Al / Ny / CPP." In the above-described laminate structure, the left side corresponds to the outer surface of the housing 22, and the right side corresponds to the inner surface of the housing 22. The material of the resin layer provided on the outer surface of the metal layer may be the same as or different from the material of the first member 22a1. In particular, using polyethylene terephthalate (PET) or polyamide (PA) as the material of the resin layer provided on the outer surface of the metal layer improves the weather resistance and impact resistance of the second member 22a2, thereby improving the weather resistance and impact resistance of the entire heat-absorbing member 20.

[0036] <Use of Heat-Absorption Member> To provide the housing 22 in which the first member 22a1 and the second member 22a2 are bonded to each other in the battery pack 1, the housing 22 of this embodiment may be folded as shown in Fig. 6. Specifically, the housing 22 may be folded starting from a straight line between the plurality of housing portions AP that extends in the direction in which the vertices PP extend in the positive second direction. As an example, the housing 22 may be folded starting from a plurality of holes H provided along the longitudinal direction of the housing 22. In this way, by using the plurality of holes H as the folding starting points, the housing can be easily folded.

[0037] The folded housing 22 may be used as the heat-absorbing member 20. The heat-absorbing member 20 is disposed adjacent to the battery 10. The term "adjacent" as used herein means that two different members face each other.

[0038] The vertices PP of the heat absorption member 20 are positioned adjacent to each other, and the two surfaces that make up the vertices PP are not adjacent to the battery 10. Therefore, when viewed as a whole, the two surfaces that make up the vertices PP act as reinforcing elements that improve the mechanical strength of the heat absorption member 20. This improves the mechanical strength of the battery pack compared to a conventional battery pack such as that shown in FIG. 9 (a battery pack in which two of the triangular surfaces are adjacent to the battery). This reduces deformation of the heat absorption member when it is incorporated into the battery pack, and reduces deformation due to vibration and / or impact during normal use of the battery pack.

[0039] Furthermore, when the apex portion PP is formed by drawing, the apex height D1 (see FIG. 7) of the heat absorption member 20 formed by four housings 22 of this embodiment can be made lower than the apex height D2 of a conventional heat absorption member 20' formed by two housings as shown in FIG. 9. This makes it possible to reduce the occurrence of cracks and pinholes due to press working.

[0040] In a preferred aspect of the first embodiment, adjacent storage portions AP may be in contact with each other (see FIG. 7 ). In this way, the contact between adjacent storage portions AP further improves the mechanical strength inside the heat absorption member, making the heat absorption member even more resistant to crushing.

[0041] In a preferred embodiment, one of the two surfaces constituting the vertex portion PP may face one of the two surfaces constituting the other vertex portion PP (see FIGS. 6 and 7). With this configuration, one of the two surfaces constituting the vertex portion PP can act as a support against external stress applied to the heat absorption member 20. This further improves the mechanical strength of the heat absorption member, making it even more difficult for the heat absorption member to collapse.

[0042] In a preferred embodiment, the surface SF (see FIG. 5) facing the apex PP may constitute the outer surface of the heat-absorbing member 20. In this specification, the "surface facing the apex" refers to the surface including the opposite side to the apex PP in the triangular-shaped storage portion AP in the cross-sectional view shown in FIG. 5. With this configuration, the surfaces other than the surface facing the apex can be used to improve the mechanical strength of the heat-absorbing member.

[0043] In a preferred embodiment, the sum of the angles formed by the vertices PP may be 360°. In this specification, the term "a mode in which the sum of the angles formed by the vertices PP is 360°" does not mean strictly 360°, but rather means allowing for an error of about ±10% from 360°. With this configuration, by combining the housing portion AP having the vertices PP, the mechanical strength of the heat absorption member can be further improved.

[0044] In a preferred embodiment, as shown in FIG. 7 , the housing body 22 may have four housing portions AP and have a rectangular prism-like outer shape when folded. The term "rectangular prism shape" as used herein is not limited to a strict rectangular prism shape, but may encompass an approximately rectangular prism shape having a configuration equivalent to the four faces of a rectangular prism, two main faces intersecting the four faces, or four corners. For example, it may encompass cases in which the four corners protrude from the faces, the four corners are rounded or flat, or the four faces are curved and / or bent. When the housing body 22 is unfolded, the four housing portions AP may be arranged in a triangular wave shape (see FIG. 4 ). When the housing body 22 is folded, its apex PP may be positioned opposite the central axis AX of the housing body 22 (see FIG. 7 ). With this configuration, each vertex PP is located inside the container 22, which has a rectangular prism-shaped outer shape, at a position opposite the central axis AX of the container 22, so that the surfaces constituting each vertex PP can act as elements that reinforce the container 22, further improving the mechanical strength of the heat absorption member.

[0045] [Functions and Effects of Battery Pack of First Embodiment] The functions and effects of the battery pack of the first embodiment configured as described above will be described with reference to Fig. 8. Fig. 8 shows a case where abnormal heat generation occurs in one of the four batteries, battery 10x.

[0046] When abnormally heated battery 10x (hereinafter also referred to as abnormally heat-generating battery) generates heat, the heat is transferred to housing 22 that is in contact with abnormally heat-generating battery 10x, causing peeling at the heat-welded portions of housing 22. Note that heat damage may also occur at portions other than the heat-welded portions.

[0047] Then, the heat-absorbing agent 21 is released from the location where the thermal welding in the housing portion AP has come off, and the released heat-absorbing agent 21 adheres to the battery (see FIG. 8). Therefore, the adhesion of the heat-absorbing agent 21 cools the battery, and it is possible to suppress a rise in the temperature of the battery.

[0048] As a mode for efficiently releasing the heat-absorbing agent 21, a plurality of holes H may be provided along the longitudinal direction of the container 22 at positions between one of the plurality of container portions AP and another of the plurality of container portions AP, at positions corresponding to the corners of the container 22 (see FIG. 5). With this configuration, the holes H are provided at the corners of the container 22 where peeling of the thermal weld is likely to occur, so that a larger amount of the heat-absorbing agent released due to peeling of the thermal weld can be released through the holes.

[0049] Furthermore, the plurality of holes H may be provided at positions between one of the plurality of storage portions AP and another of the plurality of storage portions AP, at positions where the first member 22a1 and the second member 22a2 are bonded together (see FIG. 5). With this configuration, the plurality of holes H are provided at the positions where the first member 22a1 and the second member 22a2 are bonded together, where peeling of the thermal weld is particularly likely to occur, so that the heat-absorbing agent released when the thermal weld is peeled off can be released in greater amounts by the holes provided at the positions where the first member and the second member are bonded together.

[0050] Furthermore, the corners of the housing body 22 may be located near the center position O of the shortest distance (straight line L) between the outer circumferential surface of one battery and the outer circumferential surface of another battery among the plurality of batteries 10 (see FIG. 7 ). From another perspective, the corners of the housing body 22 may be located in the inter-battery space SP (see FIG. 7 ) between one battery 10 and the other battery 10. In this specification, "near the center position of the shortest distance" and / or "inter-battery space" refers to the center position O of the shortest distance (straight line L) and the area up to a position spaced a radius R of the battery 10 from the center position O. Here, an example of the optimal position for the housing body corner may be an extension of the line L at which the distance between one battery 10 and the other battery 10 is narrowest. By positioning the first joint portion 25a in this position, the heat-absorbing agent can be attached to the batteries at the location where the most heat is exchanged between the batteries 10 (the location where the distance between the batteries 10 is narrowest), thereby improving the heat-absorbing effect. Furthermore, when viewed in the negative direction in the third direction, the housing body 22 may be disposed so that the position of a corner of the housing body 22 overlaps with the line L. Such an arrangement may improve the heat absorption effect.

[0051] [Configuration of Main Parts of Battery Pack of Second Embodiment] Next, a battery pack of a second embodiment of the present disclosure will be described with reference to Fig. 10 and Fig. 11. Fig. 10 is a schematic exploded perspective view of a heat-absorbing member of the second embodiment, and Fig. 11 is a schematic perspective view of the heat-absorbing member of the second embodiment. In addition, since the schematic cross-sectional view of the main parts of the battery pack of the second embodiment is common to the schematic cross-sectional view of the main parts shown in Fig. 7, the schematic cross-sectional view of the main parts of the battery pack of the second embodiment will be described with reference to Fig. 7.

[0052] In describing the battery pack of the second embodiment, the description of the features common to the configuration of the battery pack of the first embodiment will be omitted as appropriate. In other words, the following description will focus on the configuration that is different from the battery pack of the first embodiment.

[0053] The battery pack of the second embodiment differs from the battery pack 1 of the first embodiment in that a plurality of heat absorbing members 20b are provided.

[0054] <Heat-Absorbing Member> The heat-absorbing member 20b has a heat-absorbing agent 21 and a container 22b that accommodates the heat-absorbing agent 21 (see FIG. 11).

[0055] - Container - Container 22b is a member that contains heat-absorbing agent 21. As an example, container 22b may have a first portion 22b1 that defines container portion AP, and a second portion 22b2 that is bonded to first portion 22b1 to seal container portion AP.

[0056] First portion The first portion 22b1 may be provided with a storage portion AP that stores the heat-absorbing agent 21. In the examples shown in Figures 10 and 11, one storage portion AP is provided. Before storing the heat-absorbing agent 21, the storage portion AP has a hollow triangular prism shape, and one corner of the triangular prism shape is configured as a vertex PP.

[0057] Second Part The second part 22b2 is a member that seals the accommodation part AP in the first part 22b1. The second part 22b2 may be made of a material that can be thermally welded to the first part 22b1.

[0058] <Use of Heat-Absorbing Member> The battery pack of the second embodiment is constructed by combining, as an example, four housings 22b each having the first portion 22b1 and the second portion 22b2 bonded together. That is, in this embodiment, the vertex portion PP of one housing 22 and the vertex portion PP of another housing 22 are arranged adjacent to each other, and the two surfaces that make up the vertex portion PP are not adjacent to a battery, so that adjacent heat-absorbing members 20 are in contact with each other, thereby constructing a battery pack corresponding to that shown in FIG. 7 .

[0059] In the battery pack of the second embodiment, the two surfaces constituting the vertex portion PP also function as reinforcing elements that improve the mechanical strength of the assembly of heat-absorbing members 20. Therefore, the mechanical strength of the battery pack can be improved compared to the conventional battery pack 1 shown in Fig. 9 (a battery pack in which two surfaces of the triangular shape are adjacent to the battery). This reduces deformation of the heat-absorbing members when the assembly of heat-absorbing members is incorporated into the battery pack, and reduces deformation due to vibration and / or impact during normal use of the battery pack.

[0060] A more specific aspect of the battery pack of the second embodiment includes four or more cylindrical batteries 10, which may be arranged adjacent to one another (see FIG. 7 ). An assembly of four heat-absorbing members 20 may be arranged in the space surrounded by the batteries 10. The assembly may have a rectangular prism shape, and the vertices PP of the housings 22 b may be arranged adjacent to one another (see FIG. 7 ). With this configuration, the vertices PP are arranged adjacent to one another inside the assembly of rectangular prism-shaped housings 22 b. Therefore, the surfaces of the housings 22 b that form the vertices can act as reinforcing elements for the assembly, further improving its mechanical strength.

[0061] Each housing 22b may have a first portion 22b1 and a second portion 22b2. The first portion 22b1 of this embodiment is the same as the first member 22a1 of the first embodiment, except that there is only one housing portion AP. The second portion 22b2 of this embodiment is the same as the second member 22a2 of the first embodiment, except that it seals one housing portion AP. In this embodiment, a vertex PP is provided in the first portion. The first portion 22b1 and the second portion 22b2 are bonded to each other at the first corner C1 and the second corner C2 of the housing 22 (see FIG. 11 ). As described above, the bonding method may be thermal welding or ultrasonic welding. The first corner C1 and the second corner C2 are located near the center O of the shortest distance (the line L shown in FIG. 7 ) between the outer circumferential surface of one battery 10 and the outer circumferential surface of another battery 10 among the plurality of batteries 10. By adopting such a positional relationship, it is possible to improve the heat absorption effect.

[0062] It should be noted that the embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present disclosure should not be interpreted solely by the above-described embodiments, but should be defined based on the claims. The technical scope of the present disclosure also includes all modifications within the scope and meaning equivalent to the claims.

[0063] The battery pack of the present disclosure is as follows: <1> A battery pack comprising: a plurality of batteries; and a heat-absorbing member having a heat-absorbing agent and a housing that accommodates the heat-absorbing agent, wherein the heat-absorbing member is positioned adjacent to the batteries; the housing is triangular prism-shaped and has a plurality of housing sections that accommodate the heat-absorbing agent, wherein the vertices of the triangular prism-shaped housing sections are positioned adjacent to each other, and two faces that make up the vertices are not adjacent to the batteries. <2> The battery pack described in <1>, wherein the housing is located between the plurality of housing sections and is folded around a straight line that extends in the direction in which the vertices extend. <3> The battery pack described in <1> or <2>, wherein adjacent housing sections are in contact with each other. <4> A battery pack comprising: a plurality of batteries; and a plurality of heat-absorbing members each having a heat-absorbing agent and a housing that houses the heat-absorbing agent, wherein each of the plurality of heat-absorbing members is positioned adjacent to one of the plurality of batteries, and each of the plurality of housings is triangular prism-shaped, and one vertex of one of the triangular prism-shaped housings is positioned adjacent to one of the vertices of another of the triangular prism-shaped housings, and two surfaces that constitute the vertices are not adjacent to a battery, and adjacent heat-absorbing members are in contact with each other. <5> The battery pack described in any one of <1> to <4>, wherein one of the two surfaces that constitute the vertices faces one of the two surfaces that constitute the other vertex. <6> The battery pack described in any one of <1> to <5>, wherein the surface facing the vertex forms an outer surface of the heat-absorbing member. <7> The battery pack described in any one of <1> to <6>, wherein the sum of the angles formed by the vertices is 360°. <8> The battery pack according to any one of <1> to <3> and <5> to <7>, wherein the housing has four housing portions and has a rectangular prism-like outer shape, and when the housing is unfolded, the housing has a triangular wave shape with the four housing portions arranged side by side, and when the housing has the rectangular prism-like outer shape, each of the vertices of the housing is positioned to face a central axis of the housing, and a plurality of holes are provided along the longitudinal direction of the housing at positions between one housing portion and another housing portion of the plurality of housing portions and at positions corresponding to the corners of the housing.<9> The battery pack according to <8>, wherein the housing has a first member and a second member that define the housing portion, wherein the first member is provided with a plurality of vertices, wherein the first member and the second member are bonded together, and wherein the plurality of holes are provided between one housing portion and another housing portion of the plurality of housing portions, at a position where the first member and the second member are bonded together. <10> The battery pack according to <9>, wherein the positions corresponding to the corners of the housing are located near the center of the shortest distance between the outer peripheral surface of one battery and the outer peripheral surface of another battery of the plurality of batteries. <11> The battery pack according to any one of <4> and <5> to <7> that recites <4>, wherein the battery pack includes four or more batteries, each of which is cylindrical, wherein the four batteries are arranged adjacent to each other, and wherein an assembly of four heat absorption members is arranged in a space surrounded by the batteries, wherein the outer shape of the assembly is a rectangular prism, and the vertices of each housing are arranged in positions facing each other. <12> The battery pack according to <4>, <5> to <7>, or <11> citing <4>, wherein the housing has a first portion and a second portion, the first portion is provided with the vertex portion, the first portion and the second portion are bonded to each other at a first corner portion and a second corner portion of the housing, and the first corner portion and the second corner portion are located near a center position of the shortest distance between an outer peripheral surface of one battery and an outer peripheral surface of another battery among the plurality of batteries.

[0064] The present disclosure can be suitably used as a battery pack that further improves the mechanical strength of the housing that houses the heat-absorbing agent, and further reduces deformation of the housing when housing the heat-absorbing agent in the housing, and deformation of the housing due to vibrations and impacts during normal use of the battery pack.

[0065] 1 Battery pack 10 Battery 20 20', 20b Heat absorption member 21 Heat absorption agent 22 Housing 22a1 First member 22a2 Second member 22b1 First portion 22b2 Second portion AP Housing portion PP Apex portion AD Adhesion portion H Hole CP Core pack CS Case CS1 First case CS2 Second case HD Battery holder TB Tab OP Opening SB Control board D1, D2 Drawing depth O Center position L Straight line SF Surface facing the apex portion

Claims

1. A battery pack comprising: a plurality of batteries; and a heat absorption member having a heat absorption agent and a container for accommodating the heat absorption agent, the heat absorption member being positioned adjacent to the batteries; the container being shaped like a triangular prism and having a plurality of container sections for accommodating the heat absorption agent, the vertices of the triangular prism-shaped container sections being positioned adjacent to each other, and the two faces constituting the vertices being not adjacent to the batteries.

2. The battery pack according to claim 1, wherein the housing is folded along a straight line between the plurality of housing portions and in the direction in which the vertices extend.

3. The battery pack according to claim 1 or 2, wherein adjacent storage portions are in contact with each other.

4. A battery pack comprising: a plurality of batteries; and a plurality of heat absorption members each having a heat absorption agent and a container for accommodating the heat absorption agent, wherein each of the plurality of heat absorption members is arranged adjacent to one of the plurality of batteries, each of the plurality of containers is triangular prism shaped and arranged such that one apex of one of the triangular prism shaped containers and one apex of the other of the triangular prism shaped containers are adjacent to each other, the two faces constituting the apex are not adjacent to a battery, and adjacent ones of the heat absorption members are in contact with each other.

5. A battery pack according to any one of claims 1 to 4, wherein one of the two faces constituting the vertex faces one of the other of the two faces constituting the vertex.

6. The battery pack according to any one of claims 1 to 5, wherein the surface opposite to the apex portion constitutes the outer surface of the heat absorbing member.

7. The battery pack according to any one of claims 1 to 6, wherein the sum of the angles formed by the vertices is 360°.

8. A battery pack as claimed in any one of claims 1 to 7, wherein the housing has four storage portions and is shaped like a rectangular prism, and when the housing is unfolded, the housing has a triangular wave shape with the four storage portions arranged in parallel, and when the housing has the rectangular prism shape, each of the vertices is positioned opposite to the central axis of the housing, and a plurality of holes are provided along the longitudinal direction of the housing at positions between one storage portion and another storage portion among the plurality of storage portions, at positions corresponding to the corners of the housing.

9. A battery pack as described in claim 8, wherein the housing has a first member and a second member that define the housing portion, the first member is provided with a plurality of vertices, the first member and the second member are bonded together, and the plurality of holes are provided at positions between one housing portion and another housing portion among the plurality of housing portions, at a position where the first member and the second member are bonded together.

10. The battery pack according to claim 9, wherein the position of the corner of the container is located near the center of the shortest distance between the outer circumferential surface of one battery and the outer circumferential surface of another battery among the plurality of batteries.

11. A battery pack as described in claim 4 and any one of claims 5 to 7 which cite claim 4, wherein the battery pack has four or more batteries, each of which is cylindrical in shape, the four batteries are arranged adjacent to one another, and an assembly of four heat absorption members is arranged in a space surrounded by the batteries, the outer shape of the assembly is a rectangular prism, and the vertices of each of the containers are arranged in positions facing each other.

12. A battery pack as claimed in claim 4 and any one of claims 5 to 7 and 11 which cite claim 4, wherein the housing has a first portion and a second portion, the first portion is provided with the vertex portion, the first portion and the second portion are bonded to each other at a first corner portion and a second corner portion of the housing, and the first corner portion and the second corner portion are located near the center of the shortest distance between an outer peripheral surface of one of the plurality of batteries and an outer peripheral surface of another of the plurality of batteries.

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