Battery pack

Abstract

The invention provides a battery pack which can confirm the blocking state of a current path from the outside. In the present disclosure, provided is a battery pack provided with an outer case and a battery module housed in the outer case, the outer case being provided with a connector electrically connected to the battery module and a heat-sensitive deformation part positioned on the outer surface of the outer case, the battery module is provided with a battery and a tab which is electrically connected with the battery and the connector, the tab is provided with a fusible part, and the thermosensitive deformation part and the fusible part are connected in a mutual heat conduction manner.

Description

TECHNICAL FIELD

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

[0002] A busbar that connects external terminals of different power storage elements to each other in a conductive manner is disclosed in Patent Literature 1. The busbar is provided with a fusible portion having a width dimension smaller than other portions. In the case where an overcurrent flows, heat generated by the busbar is retained in the fusible portion, and the fusible portion is fused due to the high temperature. Thereby, the current path is blocked.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2019-029309 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] On the other hand, the inventors of the present application found that, in the structure described in Patent Literature 1, there is still room for improvement in the following aspects. In the structure described in Patent Literature 1, since the fusible portion that blocks the current path is located on the inner side of the power storage device, it is not possible to confirm from the outside whether the current path is blocked. Therefore, there is a possibility that a power storage device whose current path has been blocked is mistakenly reused.

[0008] The present disclosure was made in view of the above technical problems. That is, the main object of the present disclosure is to provide a battery pack that enables the blocking state of the current path to be confirmed from the outside.

[0009] TECHNICAL SOLUTION FOR SOLVING THE PROBLEMS

[0010] The inventors of the present application conducted intensive research in order to solve the above technical problems, and as a result, the present application, which is a battery pack that achieves the above main object, was completed.

[0011] A battery pack according to an embodiment of the present disclosure includes an outer packaging case and a battery module housed in the outer packaging case,

[0012] The outer packaging case includes a connector electrically connected to the battery module and a heat-sensitive deformation portion positioned on an outer surface of the outer packaging case,

[0013] The battery module includes a battery and a tab electrically connected to the battery and the connector,

[0014] The tab includes a fusible portion,

[0015] The thermosensitive deformable part and the fusible part are connected in a manner that allows them to conduct heat to each other.

[0016] The effects of the invention

[0017] According to one embodiment of this disclosure, a battery pack capable of externally confirming the interruption status of the current path can be provided. Attached Figure Description

[0018] Figure 1 This is a schematic perspective view showing the appearance of a battery pack according to one embodiment of the present disclosure.

[0019] Figure 2 yes Figure 1 A schematic side view of the battery pack shown.

[0020] Figure 3 It means Figure 1 A schematic cross-sectional view of the AA section of the battery pack shown.

[0021] Figure 4 Is Figure 1 The battery pack shown is a schematic side view excluding the outer packaging casing.

[0022] Figure 5 This is a schematic perspective view of a tab according to one embodiment of the present disclosure.

[0023] Figure 6 This is a schematic circuit diagram of a battery pack according to one embodiment of the present disclosure.

[0024] Figure 7 It means Figure 3 A schematic cross-sectional view of the CC section of the battery pack shown.

[0025] Figure 8 yes Figure 7 A schematic enlarged cross-sectional view of part D of the battery pack shown.

[0026] Figure 9 It is a schematic enlarged cross-sectional view showing the state of fracture of the fusible part.

[0027] Figure 10A It indicates the point before the fusible part breaks. Figure 2 A schematic enlarged view of part B of the battery pack shown.

[0028] Figure 10B It indicates the condition after the fusible part breaks. Figure 2 A schematic enlarged view of part B of the battery pack shown.

[0029] Figure 11 This is a schematic enlarged cross-sectional view of the battery pack in another embodiment.

[0030] Figure 12A It means in Figure 11 A schematic enlarged view of the state of the thermosensitive deformable part in the battery pack before the fusible part breaks.

[0031] Figure 12B It means in Figure 11 The diagram shows a schematic enlarged view of the state of the thermosensitive deformable part after the fusible part breaks in the battery pack shown.

[0032] Figure 13 This is a schematic enlarged cross-sectional view of the battery pack in another embodiment.

[0033] Figure 14 This is a schematic enlarged cross-sectional view of the battery pack in another embodiment.

[0034] Figure 15 This is a schematic enlarged cross-sectional view of the battery pack in another embodiment.

[0035] Figure 16 This is a schematic enlarged cross-sectional view of the battery pack in another embodiment.

[0036] Figure 17 It means in Figure 16 The diagram shows a schematic enlarged view of the state of the thermosensitive deformable part after the fusible part breaks in the battery pack shown.

[0037] Figure 18 This is a schematic enlarged view showing the vicinity of the thermosensitive deformation portion of the battery pack in another embodiment.

[0038] Figure 19 This is a schematic enlarged cross-sectional view of the battery pack in another embodiment.

[0039] Figure 20 This is a schematic enlarged cross-sectional view of the battery pack in another embodiment.

[0040] Explanation of reference numerals in the attached figures

[0041] 10: Thermosensitive deformable part; 11: Outer edge of the thermosensitive deformable part; 12: Concave region; 14: First region; 15: Concave part; 16: Second region; 3: Tab; 30: Convex part; 32: Fusible part; 33: Outer edge of the fusible part; 34: First tab; 36: Second tab; 50: Heat transfer part; 50a: First main surface; 50b: Second main surface; 51: Outer edge of the heat transfer part; BM: Battery module; BP: Battery pack; CB: Battery; CN: Connector; CS: Outer packaging shell; CS1: End face; CS2: Side; CSa: Outer surface; CSb: Inner surface; HD: Battery bracket; NT: Negative terminal; PT: Positive terminal. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments of the present disclosure will be specifically described. Note that the following description and examples are provided by the applicant in order to fully understand the present disclosure by those skilled in the art, and are not intended to limit the subject matter recited in the claims by these. That is, the present disclosure is not limited to the embodiments described below, and can be appropriately changed and implemented within the scope of the object. Note that, in consideration of the easiness of explanation or understanding of the gist, sometimes the description is expressed by dividing into embodiments and the like for convenience, but the substitution and / or combination of parts of the structures shown in different embodiments and the like can be made. In the description of such embodiments, sometimes the repeated description of substantially the same matters is omitted, and only the different points are described. In particular, sometimes the same effects resulting from the same structures are not mentioned one by one for each embodiment.

[0043] In the present specification, various numerical ranges mentioned, unless otherwise specifically described, include the numerical values of the lower limit and the upper limit themselves. Note that the term "about" can include a variation or difference of several percent, for example, ±10%.

[0044] Hereinafter, a battery pack according to one embodiment of the present disclosure will be described with reference to the drawings. Although the description is made with reference to the drawings as needed, the illustrated content is only schematically and exemplarily shown for understanding the present disclosure, and the appearance and the size ratio and the like can be different from the actual one.

[0045] In the present specification, the "Z direction" refers to the thickness direction of a symmetric object (for example, a battery pack), and a drawing observed from the Z direction is set as a plan view. The "Y direction" refers to the height direction of a battery housed in the battery pack, and a drawing observed from the Y direction is set as a front view. The "X direction" refers to a direction orthogonal to the Z direction and the Y direction, and a drawing observed from the X direction is set as a side view. That is, the X direction, the Y direction, and the Z direction refer to the relationship of being orthogonal to each other, respectively. Note that in the drawings, the X direction, the Y direction, and the Z direction are illustrated, and the direction of an arrow refers to the positive direction (or the + direction), and the direction opposite to the direction of the arrow refers to the negative direction (or the - direction).

[0046] In the present specification, the "cross-sectional observation" corresponds to the observation of a cross section taken in a direction perpendicular to the thickness of an arbitrary face of the outer packaging case CS, from a direction perpendicular to the extension direction of the cross section. In addition, in the present specification, the "plan view observation" corresponds to the observation of an object from a direction perpendicular to the extension direction of an arbitrary face of the outer packaging case CS (that is, the thickness direction of the face).

[0047] The present disclosure relates to a structure of a battery pack that houses a battery module. First, in order to grasp the overall structure of the battery pack of the present disclosure, the basic structure of the battery pack and the battery module of the present disclosure will be described below with reference to the drawings.

[0048] [Basic structure of battery pack]

[0049] Referring to Figures 1-3 The battery pack BP of the present disclosure will be described. Figure 1 is a schematic perspective view showing the appearance of the battery pack BP according to one embodiment of the present disclosure. Figure 2 is Figure 1 is a schematic side view of the battery pack BP shown in Figure 3 is a schematic cross-sectional view showing the A-A cross section of the battery pack BP shown in Figure 1 Figure 4 is a schematic side view of the battery pack shown in Figure 1

[0050] The battery pack BP can have an outer packaging case CS and a battery module BM housed in the outer packaging case CS (see Figure 1 and Figure 3 ). Note that detailed description of the battery module BM will be given later in the description.

[0051] The outer packaging case CS can also have a box shape that constitutes a housing space that houses the battery module BM. The outer packaging case CS can also be understood as an outer case that surrounds the battery module BM, and can also be referred to as a packaging case or the like. For example, the outer packaging case CS can have a box shape that is located on the terminal side of the battery housed in the battery pack, and has two end faces CS1 facing each other and a side surface CS2 connecting the two end faces CS1. Such an outer packaging case CS can also be constituted by the combination of two or more case members, for example.

[0052] On the outer packaging case CS, a connector CN that is electrically connected to the battery module BM can be provided. The connector CN can function as a terminal for extracting power from the battery module BM. The connector CN can be provided on the outer surface CSa of the outer packaging case CS. In the example of the battery pack BP shown in Figure 1

[0053] [Basic structure of battery module]

[0054] Referring to Figure 3 and Figure 4 ​​​The battery module BM of this disclosure will be described.

[0055] The battery module BM disclosed herein may mainly include a battery CB, a battery bracket HD, tabs 3, and a control board SB. The structure of each component is described in detail below.

[0056] -Battery-

[0057] A CB battery mainly refers to a chemical battery that converts chemical energy into direct current electricity through a chemical reaction. Figure 3 as well as Figure 4 The battery CB used in the battery module BM shown is a cylindrical battery with a cylindrical axis in the ±Y direction, but the shape of the battery is not particularly limited. For example, battery CBs with shapes other than cylindrical (such as elliptical cylindrical, rectangular cylindrical, or polygonal cylindrical, etc.) can also be used.

[0058] The battery module BM disclosed herein can have two or more battery cells CB. Furthermore, the battery cells CB can also be arranged adjacent to each other. For example, in... Figure 3 In the arrangement shown, five battery cells (CBs) are arranged in a column, adjacent to each other in the X direction, and in a matrix, combined into two columns in the +Z direction (allowing for a total of 10 battery cells (CBs)). For example, as... Figure 3 As shown, the cells CB can also be configured in an alternating pattern so that the cells CB in each column are different when viewed from the Y direction. It should be noted that the number of cells and their combination are not limited to a specific configuration. Figure 3 In this way.

[0059] -Battery bracket-

[0060] The battery holder HD functions as a component to hold and / or secure the battery CB within the receiving space of the outer packaging casing CS. For example, as... Figure 2 As shown, the battery bracket HD can be positioned on both the +Z and -Z direction sides of the battery CB. That is, the battery bracket HD is embedded into the battery CB by clamping it from both sides in the ±Z direction, thus restricting the movement of the battery CB within the outer casing CS. The number of battery brackets HD is not particularly limited, and two or more components can constitute a battery bracket HD.

[0061] For example, such as Figure 2As shown, three battery holders HD1 to HD3 can be used between the plurality of batteries CB and between the batteries CB and other constituent elements. Specifically, the first battery holder HD1 can be provided between the batteries CB and the control substrate SB, the second battery holder HD2 can be provided extending along the side surface of the outer packaging case CS on the -Z direction side and between the outer packaging case CS and the batteries CB, and the third battery holder HD3 can be provided between the rows of batteries CB. The first battery holder HD1 and the second battery holder HD2 can also be configured to fill the gaps between the batteries CB and the control substrate SB or between the batteries CB and the outer packaging case CS. For example, the first battery holder HD1 and the second battery holder HD2 can also have a side surface curved along the outer periphery of the battery CB, which can be in contact with the battery CB. Thus, the movement of the batteries CB in the ±X direction within the outer packaging case CS can be limited.

[0062] More specifically, the first battery holder HD1 can appropriately maintain the separation distance between the outer packaging case CS and the batteries CB, and can contribute to maintaining the positions of the control substrate SB and the batteries CB within the outer packaging case CS. The second battery holder HD2 can contribute to maintaining the separation distance between the outer packaging case CS and the batteries CB.

[0063] The third battery holder HD3 can also be provided between the rows of batteries CB adjacent to each other. The third battery holder HD3 can also have a shape along the side surface shape of the battery CB to be fitted into the gap present between the rows of batteries CB. With such a third battery holder HD3, the separation between the plurality of batteries CB can be appropriately maintained. For example, as shown, the battery pack BP can have a plurality of third battery holders HD3. The plurality of third battery holders HD3 can have the same shape as each other, or some of the third battery holders HD3 can have a different shape such as the third battery holder HD3a having a relief portion in the Figure 3 Figure 3 Instead, the third battery holder HD3 can be configured of one piece.

[0064] With the battery holder HD as described above, the positions of the batteries CB within the outer packaging case CS (e.g., the separation between the batteries CB) can be appropriately maintained. Thus, the damage to the battery pack BP due to the unexpected movement of the batteries CB can be suppressed. For example, the metal plate generally used as the material for the tab 3 can be appropriately suppressed from being deformed due to buckling and peeled off from the battery CB due to the movement of the battery CB.

[0065] ​The shape of the battery holder HD is not particularly limited as long as it can hold the arrangement of the battery CB as described above. For example, the battery holder HD can be provided as a single member configured by one member, and the battery CB can be held and / or fixed by being inserted from the +Y direction or the -Y direction. In addition, the direction in which the battery holder HD sandwiches the battery CB is not limited to the ±Z direction, and the battery holder HD can be configured so as to be sandwiched from both sides in the ±Y direction.

[0066] At least a part of the region of the positive terminal PT and the negative terminal NT of the battery CB can be exposed from the battery holder HD. The positive terminal PT and the negative terminal NT that are not covered by the battery holder HD can be electrically connected to the tab 3. That is, the tab 3 can be electrically connected to the battery CB in the region that is not covered by the battery holder HD.

[0067] -Tab-

[0068] As Figure 3 illustrated, the tab 3 can electrically connect the positive terminal PT and / or the negative terminal NT of the battery CB that are adjacent to each other. The tab 3 has electrical conductivity. Note that the "electrical conductivity" in the present specification means that the volume resistivity is 10 5 Ω•cm or less. For example, as Figure 3 illustrated, the tab 3 can electrically connect two batteries CB that are located in different columns and adjacent to each other in series by electrically connecting the positive terminal PT of one battery CB to the negative terminal NT of the other battery CB.

[0069] The tab 3 can function as an electrical connection member that electrically connects between a plurality of batteries CB and / or between the battery CB and the control substrate SB described later. Such a tab 3 has a fusible portion 32 that can be fused in the case where an overcurrent flows. Specifically, the fusible portion 32 can be broken by being melted by Joule heat generated in the case where an overcurrent flows. Such a fusible portion 32 can block an electrical circuit by being fused in the case where an overcurrent flows in the electrical circuit, and can function as a so-called fuse. The fusible portion 32 can also be referred to as a fuse, a fuse wire, a thermal fuse portion, an overcurrent blocking portion, a fusible portion, or the like.

[0070] The fusible portion 32 can also be provided at an arbitrary position of the tab 3 that configures an electrical circuit of the battery pack BP. For example, the fusible portion 32 can be provided on a tab that electrically connects between a plurality of batteries CB. Alternatively, as Figure 4As shown, the fusible portion 32 can also be provided between the tabs connecting the battery CB and the control board SB. Specifically, the fusible portion 32 can be located between the first tab 34 electrically connected to the battery CB and the second tab 36 electrically connected to the control board SB, electrically connecting the first tab 34 and the second tab 36 to each other. That is, the first tab 34 and the second tab 36 can be electrically connected via the fusible portion 32. In such a structure, if the fusible portion 32 melts, the electrical connection between the control board SB and the battery CB is blocked.

[0071] The material and shape of the fusible part 32 are not particularly limited as long as it can be melted by an overcurrent. For example, the fusible part 32 can be made of a low-melting-point material that melts when heated by an overcurrent. Such a fusible part 32 can be made of a different material than the parts other than the fusible part 32 (e.g., the first tab 34 and the second tab 36), and can be electrically connected using various fixing means such as riveting.

[0072] Alternatively, the fusible portion 32 may have the following structure: compared with the portion other than the fusible portion 32 in the tab 3, it has a higher resistance, which locally increases the heat generation when an overcurrent flows. Figure 5 This is a partially enlarged view schematically illustrating the fusible portion of the example electrode 3. For example, as shown... Figure 5 As shown, by locally reducing the width of the tab 3 in the fusible portion 32, the tab 3 can also have a structure in which the resistance is locally increased in the fusible portion 32. Such a fusible portion 32 can be made of the same material as the tab 3. For example, the tab 3 and the fusible portion 32 can also be formed integrally.

[0073] -Control board-

[0074] Control board SB is shown in one example Figure 3 The control board SB can be disposed on the outer surface of the battery holder HD. The control board SB can also be electrically connected to the tab 3. The control board SB can be electrically connected to the battery CB via the tab 3. Therefore, the control board SB can receive power from the battery CB via the tab 3 connected to it. Furthermore, the power output from the battery CB via the tab 3 can also be controlled.

[0075] Further components may also be included in the battery pack BP. For example, such as... Figure 3 as well as Figure 4 As shown, an insulating component INS for preventing short circuits between the battery CB and the tab 3 can also be configured between the battery CB and the tab 3.

[0076] [Features of the battery pack disclosed herein]

[0077] The battery pack disclosed herein is characterized by having a structure that allows the fusible portion 32 to be determined from the outside of the outer packaging shell CS. This feature will now be described in detail with reference to the accompanying drawings.

[0078] like Figure 2 As shown, the outer packaging shell CS has a heat-sensitive deformable portion 10 on its outer surface CSa. In short, the "heat-sensitive deformable portion" in this specification refers to a part configured to deform according to temperature. More specifically, the heat-sensitive deformable portion 10 is a part configured to deform to a degree that can be visually judged by applying heat. That is, the heat-sensitive deformable portion 10 is a part that can deform to a degree that allows visual judgment of the difference between its shape before and after applying heat. The method of deformation is not particularly limited as long as it can be visually judged; for example, deformation caused by partial melting, expansion, contraction, fracture, and / or melting can be listed. Such a heat-sensitive deformable portion 10 may also be referred to as a heat-deformable portion, a heat-responsive shape-variable portion, a heat-sensitive shape-variable part, etc.

[0079] The thermosensitive deformable portion 10 is connected to the fusible portion 32 of the tab 3 housed within the outer packaging casing CS in a manner capable of heat conduction. "Connected in a manner capable of heat conduction" is not limited to a direct connection, but also includes a connection via any heat-conducting component. That is, the battery pack BP of this disclosure can be configured such that heat generated by the fusible portion 32 can be transferred to the thermosensitive deformable portion 10. This structure can also be understood as the thermosensitive deformable portion 10 being thermally connected to the fusible portion 32. With this structure, the thermosensitive deformable portion 10 can change shape in response to heat generated in the fusible portion 32.

[0080] As described above, the fusible portion 32 is melted by Joule heating generated by an abnormal overcurrent. The heat generated at this time is transferred to the thermosensitive deformable portion 10 located on the outer surface CSa of the outer packaging shell CS, thereby enabling the thermosensitive deformable portion 10 to deform. The thermosensitive deformable portion 10 is configured to deform according to the heat transmitted from the fusible portion 32 when the temperature at which the fusible portion 32 melts due to overcurrent (hereinafter also simply referred to as the "melting temperature") is reached. In short, when the fusible portion 32 of the tab 3 reaches the melting temperature, a shape change occurs in the thermosensitive deformable portion 10 of the outer packaging shell CS. More specifically, the thermosensitive deformable portion 10 can deform when the fusible portion 32 reaches the melting temperature and is heated to a predetermined temperature due to the heat transmitted from the fusible portion 32. On the other hand, when the fusible portion 32 is below the melting temperature, the thermosensitive deformable portion 10 does not deform.

[0081] According to the structure of this disclosure, the thermosensitive deformable portion 10 can function as an indicator of the melting state of the fusible portion 32. The operator can determine whether the fusible portion 32 has reached the melting temperature by checking the presence or absence of shape changes of the thermosensitive deformable portion 10 on the outer surface CSa of the outer packaging shell CS. That is, the melting state regarding whether the fusible portion 32 inside the outer packaging shell CS has melted can be confirmed from the outside of the outer packaging shell CS.

[0082] According to this disclosure, the fusible state of the fusible portion 32 can be determined indirectly from the outside, without the need for openings such as windows in the outer casing CS, or for direct identification by disassembling the battery pack BP. Therefore, the fusible state of the fusible portion 32 can be determined without exposing the battery module BM housed in the outer casing CS to the outside. Consequently, when confirming the fusible state of the fusible portion 32, the intrusion of foreign matter such as moisture and / or dust into the battery module BM can be appropriately suppressed.

[0083] Furthermore, the battery pack structure disclosed herein is advantageous when it includes multiple fusible portions 32. For example, as a means of confirming the fusible state of the fusible portion 32, confirming the conduction state can be considered. However, when the battery pack includes multiple fusible portions 32, it is difficult to determine from the outside which fusible portion 32 has fused.

[0084] In particular, when the battery module BM has a parallel circuit consisting of multiple battery CBs connected in parallel, at least one fusible part 32 is assembled for each of the battery CBs. Figure 6 This is a schematic circuit diagram of a battery pack BP, illustrating an example of a parallel circuit. As shown, the battery pack BP can have two battery groups CBs and CBsA, each consisting of multiple batteries CB. Alternatively, the positive terminal PE of battery group CBs can be connected to the positive terminal PE of battery group CBsA and led to connector CN (see reference). Figure 1 The external positive terminal PTE of the connector CN. Similarly, the negative terminals NE of battery packs CBs and CBsA can be connected and guided to the external negative terminal NTE of connector CN. Thus, battery packs CBs and CBsA can be connected in parallel. Fusible portions 32, 32A can be inserted into each of the two battery packs CBs and CBsA. The outer packaging shell CS can have multiple heat-sensitive deformable portions 10, 10A connected to each of the fusible portions 32, 32A in a manner that enables heat conduction (see reference). Figure 3 Specifically, the outer packaging shell CS may include a thermosensitive deformable part 10 and a thermosensitive deformable part 10A. The thermosensitive deformable part 10 is connected to the fusible part 32 in a manner that enables heat conduction, and the thermosensitive deformable part 10A is connected to the fusible part 32A in a manner that enables heat conduction.

[0085] In the event of an abnormal current flowing through a battery module BM in such a parallel circuit, the applied voltage of the circuit temporarily decreases when any one of the multiple fusible parts 32 blows, which may prevent the other fusible parts 32 from being disconnected. That is, in the battery module BM, there may be battery CB groups where the fusible parts 32 have blown and battery CB groups where the fusible parts 32 have not blown. In such a battery module BM, since the electrical circuit is not completely blocked, it is impossible to determine the blowing state of the fusible parts 32 based on the presence or absence of conduction. If such a battery module BM is used normally, the required number of parallel connections of battery CBs cannot be guaranteed when connected in parallel, and overcurrent exceeding the design-intended limits may flow in battery CB groups with residual circuitry.

[0086] According to this disclosure, by providing multiple heat-sensitive deformable portions 10 connected to each of the multiple fusible portions 32 in a manner capable of heat conduction, the melting state of each of the multiple fusible portions 32 can be identified from the outside of the outer packaging shell CS. That is, it can be confirmed from the outside of the battery pack BP which of the multiple fusible portions 32 has melted, and whether there are any fusible portions 32 that have not melted. In this way, by clearly indicating whether the fusible portion 32 has melted in a manner that can be identified from the outside, continued use of a faulty battery pack BP can be prevented.

[0087] Figure 7 It is a schematic representation Figure 3 The figure shows a cross-sectional view of the CC section of the thermosensitive deformable portion 10. It should be noted that the BB section is a section cut along the thickness direction T (hereinafter also simply referred to as "the thickness direction T of the outer packaging shell CS") of the surface where the thermosensitive deformable portion 10 is located. As shown, the thermosensitive deformable portion 10 and the fusible portion 32 can be arranged opposite each other in the thickness direction T of the outer packaging shell CS. For example, the thermosensitive deformable portion 10 and the fusible portion 32 can be located coaxially in the thickness direction T of the outer packaging shell CS. In this specification, "located coaxially" means that, when viewed from the thickness direction T of the outer packaging shell CS, the thermosensitive deformable portion 10 and the fusible portion 32 have a configuration that at least partially overlaps.

[0088] According to this structure, the thermosensitive deformable portion 10 is disposed on the outer surface CSa of the outer packaging shell CS at a position corresponding to the placement location of the fusible portion 32. This shortens the distance between the thermosensitive deformable portion 10 and the fusible portion 32, allowing heat from the fusible portion 32 to be transferred to the thermosensitive deformable portion 10 more appropriately. Therefore, the thermosensitive deformable portion 10 can more appropriately reflect the melting state of the fusible portion 32.

[0089] Furthermore, since the thermosensitive deformable portion 10 is positioned corresponding to the fusible portion 32 within the outer packaging shell CS, the operator can perceive the configuration of the fusible portion 32 from the outside of the outer packaging shell CS. This structure is particularly advantageous when the battery module BM has multiple fusible portions 32. For example, each of the multiple thermosensitive deformable portions 10 can be positioned corresponding to each of the multiple fusible portions 32. By identifying each of the thermosensitive deformable portions 10 from the outside of the outer packaging shell CS, the operator can easily determine in which position the fusible portion 32 has melted. That is, according to this disclosure, the position of the melted fusible portion 32 can be identified from the outside of the outer packaging shell CS.

[0090] The fusible portion 32 can contact the inner surface CSb of the outer packaging shell CS at a position opposite to the thermosensitive deformable portion 10. In other words, the outer packaging shell CS can have the thermosensitive deformable portion 10 on its outer surface CSa, and on the other hand, the fusible portion 32 can contact the inner surface CSb opposite to the thermosensitive deformable portion 10. As a result, the distance of thermal movement from the fusible portion 32 to the thermosensitive deformable portion 10 can be substantially the same as the thickness of the outer packaging shell CS. Therefore, more efficient thermal movement from the fusible portion 32 to the thermosensitive deformable portion 10 can be achieved, and the thermal responsiveness of the thermosensitive deformable portion 10 to the temperature rise relative to the fusible portion 32 can be improved.

[0091] The thermosensitive deformable portion 10 can also be formed of a material capable of deforming according to temperature. Preferably, the thermosensitive deformable portion 10 can be integrally molded with the outer packaging shell CS. The material of such an outer packaging shell CS can be, for example, a thermoplastic resin material (e.g., plastic) or a metal material. Examples of resin materials include polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polycarbonate ABS (PCABS), polybutylene terephthalate (PBT), polyethylene, nylon, modified polyphenylene ether (m-PPE), polyamide (PA), etc. Examples of metal materials include aluminum.

[0092] When the thermosensitive deformable portion 10 is integrally molded with the outer packaging shell CS, the material of the outer packaging shell CS is more preferably a thermoplastic resin material. Generally speaking, thermoplastic resin materials have poor thermal conductivity compared to metals. Therefore, if the outer packaging shell CS is made of thermoplastic resin material, the heat transferred from the fusible portion 32 to the thermosensitive deformable portion 10 is difficult to diffuse throughout the entire outer packaging shell CS, and deformation caused by thermal response can occur locally in the thermosensitive deformable portion 10. As a result, the thermosensitive deformable portion 10 can more clearly display the heating state in the fusible portion 32 (i.e., the fracture state of the fusible portion 32).

[0093] Figure 8 yes Figure 7The diagram shows a schematic enlarged view of portion C of the battery pack BP. As shown, the thermosensitive deformable portion 10 may have a recess 15 in which the thickness of the outer packaging shell CS is partially reduced. In other words, the thermosensitive deformable portion 10 can be formed by having a recess 15 in which the thickness of the outer packaging shell CS is partially reduced on the outer surface CSa of the outer packaging shell CS. With this shape, the thermosensitive deformable portion 10 can change shape in the recess 15 by heat transferred from the fusible portion 32. That is, according to the battery pack of this disclosure, the melting state of the fusible portion 32 can be determined by the shape change of the recess 15 formed in the thermosensitive deformable portion 10.

[0094] The shape of the recess 15 changes according to its shape before the shape change (i.e., before the fusible portion 32 melts). For example, in... Figure 8 The thermally deformable portion 10 shown includes multiple tiny recesses 15 and, as shown, a thermosensitive deformable portion 10. Figure 16 The thermosensitive deformable portion 10 shown includes a recess 15 formed by recessing the entire thermosensitive deformable portion 10. The shape of the thermosensitive deformable portion 10 can change in different ways. Hereinafter, the manner in which the thermosensitive deformable portion 10 includes a plurality of tiny recesses 15 will be described first.

[0095] like Figure 8 As shown, the outer surface CSa of the outer packaging shell CS can have a wrinkled area with a plurality of tiny recesses 15 formed in the heat-sensitive deformation portion 10. That is, the heat-sensitive deformation portion 10 can be wrinkled. This can also be understood as the outer surface CSa of the outer packaging shell CS in the heat-sensitive deformation portion 10 becoming a tiny uneven surface with a fine uneven shape.

[0096] In this specification, "wrinkle" refers to a shape with a repeating pattern of fine bumps and depressions on the outer surface CSa. The repeating pattern of bumps and depressions is not necessarily regular; it can also include multiple inconsistent bumps and depressions. A wrinkled area refers to the area where a wrinkling process has been performed; it can also be called a micro-bump area, a fine bump area, or an embossed area, etc. Figure 8 In the diagram, for ease of understanding, the undulations of the wrinkled areas are schematically illustrated, but may differ from the actual dimensions of the undulations. In later figures, for easier observation, the areas with folded textures are sometimes shaded, and the undulation shapes are omitted.

[0097] In the wrinkled area, the light incident on it is diffused, thus creating a difference in gloss between the wrinkled area and the non-wrinkled area. Therefore, based on this difference in gloss, the wrinkled area and the non-wrinkled area can be visually distinguished.

[0098] The average height of the unevenness in the wrinkled area can be, for example, 3 μm or more. By keeping the average height within the above range, the gloss difference between the wrinkled and non-wrinkled areas can be appropriately determined. There is no particular upper limit to the average height; for example, it can be 100 μm or less. It should be noted that the average height is a value measured using a stylus-type surface roughness measuring device according to JISB0651:2001, according to the method specified in JISB0601:2001.

[0099] Figure 9 It means in Figure 8 The image shows a partial enlarged view of the state after the fusible part 32 in the battery pack BP has melted. Additionally, Figure 10A as well as Figure 10B These are observed from the outside of the outer packaging shell CS. Figure 8 A partially enlarged view of the thermally deformable part 10 shown. Figure 10A This indicates the state of the fusible part 32 before it melts. Figure 10B This indicates the state after the fusible portion 32 has melted. As shown, in the wrinkled region of the thermosensitive deformable portion 10, the shape of the unevenness forming the wrinkled region changes due to heat from the fusible portion 32. This shape change alters the gloss of the wrinkled region. For example, the unevenness of the wrinkled region may become smoother due to heat transferred from the fusible portion 32. Here, "the unevenness becomes smoother" includes not only a reduction in the unevenness but also a smoothing of the outer contour shape of the convex portion constituting the unevenness. Specifically, the shape change of the thermosensitive deformable portion 10 includes not only a reduction in the average height of the unevenness in the wrinkled region but also a reduction in the curvature of the leading edge of the convex portion included in the wrinkled region.

[0100] By altering the shape of its uneven surface, the gloss of the thermosensitive deformable portion 10 changes before and after the fusible portion 32 melts. For example, by reducing the unevenness in the wrinkled area to approach a smooth plane, the scattering of light incident on the thermosensitive deformable portion 10 from the outside of the battery pack BP can be suppressed, resulting in a glossier appearance compared to before the shape change. Alternatively, by reducing the curvature of the corners located on the front end side of the convex portion (e.g., the front end of the convex portion), the convex portion becomes more rounded, and the scattering of light incident on the thermosensitive deformable portion 10 is suppressed. Thus, a glossier appearance is achieved compared to before the shape change. The melting state of the fusible portion 32 can be determined by this change in the gloss of the thermosensitive deformable portion 10. If the viewpoint of making the determination based on such gloss difference easier is emphasized, it is preferable that the wrinkled area includes a convex portion with sharp (e.g., large curvature) corners to make the change in gloss accompanying the deformation of the convex portion more obvious.

[0101] When the thermosensitive deformable portion 10 has a wrinkled area, the heat transmitted from the fusible portion 32 may differ within that area. Due to this heat difference, the shape variation of the wrinkled area also differs, potentially resulting in uneven gloss on the thermosensitive deformable portion 10. For example, the thermosensitive deformable portion 10 may be configured such that, when the fusible portion 32 reaches its melting temperature, a predetermined degree of gloss difference occurs due to the heat transferred to the thermosensitive deformable portion 10. That is, the operator can determine whether the heated fusible portion 32 has melted by checking the degree of uneven gloss in the thermosensitive deformable portion 10.

[0102] For example, the thermosensitive deformable portion 10 can also be configured such that when the fusible portion 32 reaches its melting temperature, the area of ​​gloss change in the thermosensitive deformable portion 10 exceeds a certain area. According to this structure, when the area of ​​gloss change in the thermosensitive deformable portion 10 exceeds a certain range, it can be determined that the fusible portion 32 has melted. Specifically, as... Figure 10A as well as Figure 10B As shown, the thermosensitive deformable portion 10 has a first region 14 and a second region 16, and wrinkling processing can be uniformly applied to both regions. For example, the central region of the thermosensitive deformable portion 10 can be designated as the first region 14, and the region surrounding the first region 14 can be designated as the second region 16. The thermosensitive deformable portion 10 can also be configured such that, when the fusible portion 32 reaches its melting temperature, at least the entire area of ​​the first region 14 undergoes a shape change in a manner that displays a different gloss than the second region 16. This makes it easier to identify shape changes in the thermosensitive deformable portion 10.

[0103] In this structure, in order to identify the range of the first region 14 used to determine the melting state of the fusible part 32, a mark such as a line indicating the position of the outer edge can be marked on the outer edge of the first region 14. This mark can be formed by any method, such as printing by screen printing or laser marking.

[0104] It should be noted that, although in Figure 10A as well as Figure 10B The figure shows a thermosensitive deformable part 10 that is approximately circular when viewed from the thickness direction T of the outer packaging shell CS. However, the shape of the thermosensitive deformable part 10 is not limited to an approximately circular shape. For example, when viewed from the thickness direction T of the outer packaging shell CS, the thermosensitive deformable part 10 may have an oblong shape, an ellipse, or a polygon such as a triangle or quadrilateral, or an irregular arbitrary shape.

[0105] Figure 11 It is a schematic representation of... Figure 8An enlarged cross-sectional view of the periphery of the thermosensitive deformation portion 10 of the battery pack BP according to another different embodiment. As shown, wrinkling can also be performed on the area CSa1 of the outer surface CSa of the outer packaging shell CS other than the thermosensitive deformation portion 10. For example, wrinkling can also be performed on the entire area of ​​the outer surface CSa other than the thermosensitive deformation portion 10.

[0106] Preferably, such as Figure 11 As shown, wrinkling is performed on the heat-sensitive deformable portion 10, but wrinkling is not performed on the area adjacent to the heat-sensitive deformable portion. That is, the outer packaging shell CS may include a non-wrinkled area CSa2 adjacent to the wrinkled area of ​​the heat-sensitive deformable portion 10 on its outer surface CSa. Alternatively, the outer surface CSa of the outer packaging shell CS may be wrinkled on its entire surface except for the non-wrinkled area CSa2. In other words, in the outer packaging shell CS, only the non-wrinkled area CSa2 is not wrinkled.

[0107] The non-wrinkled region CSa2 is a region with a gentler surface compared to the wrinkled region, but it does not necessarily have to be a smooth surface without any bumps. For example, the difference in gloss between the wrinkled and non-wrinkled regions can be appropriately determined by the lower density of bumps relative to the wrinkled region (e.g., the number of bumps per unit area (peak density Spd)).

[0108] Figure 12A 12B and 12B are observed from the outside of the outer packaging shell CS. Figure 11 A partially enlarged view of the thermally deformable part 10 shown. Figure 12A This indicates the state of the fusible part 32 before it melts. Figure 12B This indicates the state after the fusible part 32 has melted. For example... Figure 12A As shown, the non-wrinkled region CSa2, which has not undergone wrinkling, can also be positioned in a strip shape along the outer edge 11 of the thermo-deformable portion 10, surrounding it. That is, an annular non-wrinkled region CSa2 can also exist around the thermo-deformable portion 10. In this structure, wrinkling can be performed on both the inner and outer sides of the non-wrinkled region CSa2 on the outer surface CSa of the outer packaging shell CS.

[0109] Thus, in the case of an outer packaging shell CS having a heat-sensitive deformable portion 10 including a wrinkled area and an outer shell CS adjacent to a non-wrinkled area CSa2, if the fusible portion 32 melts due to an overcurrent, the heat generated in the fusible portion 32 is transferred to the heat-sensitive deformable portion 10. Through the transferred heat, the wrinkles of the heat-sensitive deformable portion 10 change shape, and the uneven shape becomes smoother. This reduces the gloss difference between the heat-sensitive deformable portion 10 including the wrinkled area and the non-wrinkled area CSa2 adjacent to the wrinkled area (see reference). Figure 12BAccording to such a battery pack BP, the non-wrinkled region CSa2 can function as a benchmark for determining the change in gloss accompanying the shape change of the thermosensitive deformable portion 10. For example, the thermosensitive deformable portion 10 can be configured such that, when the fusible portion 32 reaches the melting temperature, the shape changes to display a gloss level equivalent to that of the non-wrinkled region CSa2 due to heat transferred from the fusible portion 32. Thus, by checking the gloss difference between the thermosensitive deformable portion 10 and the non-wrinkled region CSa2, the operator can appropriately determine the melting state of the fusible portion 32.

[0110] In addition, such as Figure 8 As shown, the tab 3, which includes a fusible portion 32, may include a convex portion 30 that protrudes toward the outer packaging shell CS in cross-sectional view. The fusible portion 32 may be located at the top of this convex portion 30. In other words, the tab 3 may include a convex portion 30 formed in such a way that the fusible portion 32 protrudes toward the outer packaging shell CS. Thus, in the event of an overcurrent, the tab 3 can melt at the top of the convex portion 30. For example, the convex portion 30 may be formed by bending or folding a first tab 34 and a second tab 36 located on both sides of the fusible portion 32 toward the outer packaging shell CS on the fusible portion 32 side. With this convex portion 30, the fusible portion 32 can be positioned closer to the outer packaging shell CS than the first tab 34 and the second tab 36. Thus, the heat generated in the fusible portion 32 can be more properly transferred to the heat-sensitive deformable portion 10.

[0111] Such a convex portion 30 can elastically deform in the thickness direction T of the outer packaging shell CS. This convex portion 30 can be held in an elastically compressed state inside the outer packaging shell CS, between the outer packaging shell CS and the battery CB. The elastically compressed convex portion 30 can apply a force between the outer packaging shell CS and the battery CB. Specifically, by housing the convex portion 30 in an elastically compressed state within the outer packaging shell CS, the fusible portion 32 located at the top of the convex portion 30 can be forceped towards the outer packaging shell CS. According to this structure, the fusible portion 32 can be pressed towards the outer packaging shell CS side. Therefore, the heat generated by the fusible portion 32 can be more appropriately transferred to the heat-sensitive deformable portion 10 located in the outer packaging shell CS.

[0112] For example, such as Figure 8As shown, the convex portion 30 can be elastically deformed by having a stepped shape that bends in stages toward the outer packaging shell CS. That is, the convex portion 30 can also be formed into a stepped convex portion 30 by bending the first tab 34 and the second tab 36 into crank shapes on both sides of the fusible portion 32. With such a bending shape, the convex portion 30 can elastically deform in the thickness direction T of the outer packaging shell CS inside the outer packaging shell CS.

[0113] Next, refer to Figures 13-19 A modified example of the battery pack BP will be described. It should be noted that, in describing the modified battery pack BP, points common to the above description will be appropriately omitted. That is, the following description will focus on the differences from the above description.

[0114] [Variation Example 1]

[0115] Figure 13 This is a schematic enlarged cross-sectional view of the periphery of the thermosensitive deformable portion 10 of the battery pack BP in Modified Example 1. As shown, the outer packaging shell CS may have a concave region 12 in the region where the thermosensitive deformable portion 10 is located, where the inner surface CSb of the outer packaging shell CS is recessed. That is, the outer packaging shell CS may have the thermosensitive deformable portion 10 on its outer surface CSa, while having a concave region 12 on its inner surface CSb opposite to the thermosensitive deformable portion 10, thereby relatively reducing the thickness. In the outer packaging shell CS, the inner surface CSb may be recessed in the region where the thermosensitive deformable portion 10 is located, thereby locally reducing the thickness.

[0116] In the battery pack BP disclosed herein, from the viewpoint of improving the thermal responsiveness of the thermosensitive deformable portion 10 caused by heat transferred from the fusible portion 32, it is preferable to have a higher thermal conductivity from the fusible portion 32 to the thermosensitive deformable portion 10. By providing the aforementioned concave region 12, and by reducing the thickness of the outer packaging shell CS, the distance between the thermosensitive deformable portion 10 located on the outer surface CSa of the outer packaging shell CS and the fusible portion 32 located on the inner side of the outer packaging shell CS can be shortened. Therefore, the heat generated by the fusible portion 32 can be appropriately transferred to the thermosensitive deformable portion 10. The melting state of the fusible portion 32 from the fusible portion 32 can be clearly reflected by the thermosensitive deformable portion 10.

[0117] [Variation Example 2]

[0118] Figure 14 as well as Figure 15This is a schematic enlarged cross-sectional view of the periphery of the thermosensitive deformable portion 10 of the battery pack BP in Modified Example 2. As shown, the battery pack BP may also include a heat transfer portion 50 located between the thermosensitive deformable portion 10 and the fusible portion 32. The heat transfer portion 50 is capable of heat transfer with both the thermosensitive deformable portion 10 and the fusible portion 32. The thermosensitive deformable portion 10 and the fusible portion 32 can be connected via the heat transfer portion 50 in a manner capable of heat conduction.

[0119] The heat transfer section 50 can be located inside the outer packaging shell CS. Therefore, the heat transfer section 50 can be clamped between the outer packaging shell CS and the battery module BM in a manner that places it between the thermosensitive deformable section 10 and the fusible section 32. Such a heat transfer section 50 can be understood as a clamping component with thermal conductivity, or it can also be called a heat transfer clamping component, etc. From the viewpoint of efficiently transferring the heat generated in the fusible section 32 to the thermosensitive deformable section 10, such a heat transfer section 50 can also function as a heat collection component.

[0120] By providing the heat transfer section 50, the heat generated by the fusible section 32 is indirectly transferred to the thermosensitive deformable section 10 via the heat transfer section 50. Thus, by arranging the heat transfer section 50 between the fusible section 32 and the thermosensitive deformable section 10, a heat transfer path from the fusible section 32 to the thermosensitive deformable section 10 can be formed. Consequently, the heat generated by the fusible section 32 is appropriately transferred through the thermosensitive deformable section 10, improving the thermal responsiveness of the thermosensitive deformable section 10.

[0121] The heat transfer section 50 has a first main surface 50a and a second main surface 50b that are opposite to each other. For example... Figure 14 As shown, the first main surface 50a of the heat transfer section 50 can contact the region in the inner surface CSb of the outer packaging shell CS that faces the thermosensitive deformable section 10. In other words, the heat transfer section 50 can be arranged opposite the thermosensitive deformable section 10 in the thickness direction T of the outer packaging shell CS, and contact the inner surface CSb of the outer packaging shell CS on the first main surface 50a. On the other hand, the second main surface 50b of the heat transfer section 50 can contact the fusible section 32. With this structure, the heat transfer section 50 can contact both the outer packaging shell CS and the fusible section 32. As a result, the heat generated by the fusible section 32 can be appropriately transferred to the thermosensitive deformable section 10 located on the outer surface CSa side of the outer packaging shell CS.

[0122] Furthermore, by using the heat transfer section 50, the heat generated in the fusible section 32 can be locally transferred to the heat-sensitive deformable section 10 of the outer packaging shell CS. For example, as Figure 15As shown, even when the tab 3 extends substantially parallel to the inner surface of the outer packaging shell CS, covering the first tab 34, the fusible portion 32, and the second tab 36, by sandwiching the heat transfer portion 50 between the outer packaging shell CS and the fusible portion 32, heat transfer generated in the fusible portion 32 to areas of the outer packaging shell CS other than the heat-sensitive deformation portion 10 (e.g., region CSa1) can be suppressed. Therefore, accidental deformation of the outer packaging shell in areas other than the heat-sensitive deformation portion 10 can be suppressed.

[0123] [Variation Example 3]

[0124] Figure 16 This is a schematic enlarged cross-sectional view of the periphery of the thermosensitive deformation part 10 of the battery pack BP in modified example 3. Figure 17 It is a schematic representation in Figure 16 The diagram shows an enlarged cross-sectional view of the battery pack BP after the fusible portion 32 has melted. As shown, when the temperature at which the fusible portion 32 melts is reached, the thermally sensitive deformation portion 10 can be configured to crack due to heat propagating from the fusible portion 32.

[0125] For example, such as Figure 16 As shown, the battery pack BP may also include a recess 15 formed by the overall indentation of the thermosensitive deformable portion 10. Through the recess 15, the outer packaging shell CS can locally reduce its thickness within the thermosensitive deformable portion 10. The thermosensitive deformable portion 10 can crack in the recess 15 due to heat transferred from the fusible portion 32 (see reference). Figure 17 Therefore, the recess 15 of the thermal deformation part 10 (refer to...) Figure 16 The structure can be designed such that the thermosensitive deformable portion 10 can crack when the fusible portion 32 reaches the melting temperature. Based on this structure, the operator can determine whether the fusible portion 32 has melted by checking whether the thermosensitive deformable portion 10 has cracked.

[0126] Furthermore, when the thermosensitive deformable portion 10 is provided, other components such as a heat transfer portion 50 can be disposed on the inner side of the outer packaging shell CS opposite to the thermosensitive deformable portion 10. Holes created in the outer packaging shell CS by the cracking of the thermosensitive deformable portion 10 can also be blocked by this component. Therefore, even after the thermosensitive deformable portion 10 cracks, the intrusion of moisture and / or foreign matter into the interior of the outer packaging shell CS can be suppressed, protecting the battery module BM housed within the outer packaging shell CS.

[0127] Furthermore, the operator can confirm the exposure of components such as the heat transfer section 50 located on the inner side of the outer packaging shell CS by observing the hole formed by the crack in the heat-sensitive deformation section 10, thereby determining whether the heat-sensitive deformation section 10 is cracked. From the viewpoint that it is easier for the operator to identify whether there is a crack (i.e., whether the heat transfer section 50 or the like is exposed), the heat transfer section 50 and the outer surface CSa of the outer packaging shell CS can be colored differently from each other.

[0128] In this way, the heat transfer section 50 can function by plugging the cracked portion when the heat-sensitive deformation section 10 cracks due to heat transferred from the fusible section 32 (see reference). Figure 17 Furthermore, since the heat transfer section 50 is located between the outer packaging shell CS and the fusible section 32, it can protect the outer packaging shell CS from the influence of the fusible section 32's fused end. For example, even if the shape change of the heat-sensitive deformable section 10 in the fused state of the fusible section 32 does not result in cracking, the outer packaging shell CS may still crack accidentally due to contact between the fused fusible section 32's front end and the outer packaging shell CS. Figure 16 The structure of the heat transfer section 50 shown can be configured such that the outer packaging shell CS and the fusible section 32 do not contact each other, thus suppressing damage to the outer packaging shell CS caused by the fusible section 32 after it has been fused.

[0129] The heat transfer portion 50 may also be formed of a thermally conductive material. Preferably, the heat transfer portion 50 is made of a material with appropriate heat capacity and thermal resistance, so that when the fusible portion 32 reaches its melting temperature, heat transfer can occur to allow the thermosensitive deformable portion 10 to change shape; on the other hand, when the fusible portion 32 is below its melting temperature, the thermosensitive deformable portion 10 does not change shape. For example, the heat transfer portion 50 may be formed of various materials such as metal, ceramic, metal-ceramic composites, inorganic materials, or thermally conductive resins. Although this is just an example, the thermal resistance of the heat transfer portion 50 may, for example, be 1900°C / W or less. Furthermore, if it is important to properly protect the outer packaging shell CS from the fusible portion 32 after melting, it is more preferable that the heat transfer portion 50 is formed of a material with better heat resistance than the outer packaging shell CS.

[0130] Figure 18 This is a partially enlarged view of the heat-sensitive deformable part 10, viewed from the outside of the outer packaging shell CS. In the figure, dashed lines indicate the positions of the heat transfer part 50 and the tabs 3 located inside the outer packaging shell CS. The shape of the heat transfer part 50, viewed from above, is not particularly limited; it can be approximately circular, elliptical, rectangular, or any irregular shape. Figure 18As shown, viewed from the thickness direction T of the outer packaging shell CS, the heat transfer section 50 can have a larger external dimension than the fusible section 32. For example, when both the heat transfer section 50 and the fusible section 32 have rectangular shapes, the length and width dimensions of the heat transfer section 50 can be larger than the length and width dimensions of the fusible section 32.

[0131] Specifically, viewed from the thickness direction T of the outer packaging shell CS, the outer edge 33 of the fusible portion 32 can be located on the inner periphery of the outer edge 51 of the heat transfer portion 50. In other words, viewed from the thickness direction T of the outer packaging shell CS, the heat transfer portion 50 can extend to the outer periphery of the fusible portion 32. Viewed from the thickness direction T of the outer packaging shell CS, the fusible portion 32 can be arranged to overlap with the heat transfer portion 50 throughout its entire area. Thus, the heat generated in the fusible portion 32 can be appropriately transferred to the heat-sensitive deformable portion 10 via the heat transfer portion 50. Furthermore, even after the fusible portion 32 melts, the outer packaging shell CS can be appropriately protected because the heat transfer portion 50 is sandwiched between the entire fusible portion 32 and the outer packaging shell CS.

[0132] Furthermore, viewed from the thickness direction T of the outer packaging shell CS, the outer edge 11 of the thermosensitive deformable portion 10 can be located on the inner periphery of the outer edge 51 of the heat transfer portion 50. In other words, viewed from the thickness direction T of the outer packaging shell CS, the heat transfer portion 50 can extend to the outer periphery of the thermosensitive deformable portion 10. Viewed from the thickness direction T of the outer packaging shell CS, the thermosensitive deformable portion 10 can be arranged to overlap with the heat transfer portion 50 over its entire area. Thus, even if the outer packaging shell CS cracks due to the deformation of the thermosensitive deformable portion 10, the heat transfer portion 50 can properly block the hole formed along with the crack.

[0133] [Variation Example 4]

[0134] Figure 19 This is a schematic enlarged cross-sectional view of the periphery of the thermosensitive deformable portion 10 of the battery pack BP in Modified Example 4. As shown, the outer packaging shell CS may have a concave region 12 on its inner surface CSb, and a heat transfer portion 50 is disposed inside the concave region 12. According to this structure, the thickness of the outer packaging shell CS is reduced by the concave region 12. Therefore, while protecting the outer packaging shell CS through the heat transfer portion 50, heat can be effectively transferred from the fusible portion 32 to the thermosensitive deformable portion 10.

[0135] [Variation Example 5]

[0136] Figure 20This is a schematic enlarged cross-sectional view of the periphery of the heat-sensitive deformable portion 10 of the battery pack BP in Modified Example 5. As shown, the heat transfer portion 50 can be positioned on the inner surface CSb of the outer packaging shell CS and is integral with the outer packaging shell CS. For example, the heat transfer portion 50 and the outer packaging shell CS can be integrally formed. Therefore, the outer packaging shell CS has a protrusion protruding from the inner surface CSb toward the battery module BM, which can function as the heat transfer portion 50. The fusible portion 32 can contact the top surface 50b of the convex heat transfer portion 50 protruding from the inner surface CSb of the outer packaging shell CS.

[0137] By integrally molding the heat transfer section 50, the thickness of the outer packaging shell CS is locally increased in the region where the heat-sensitive deformation section 10 is located. As a result, the strength of the outer packaging shell CS in the heat-sensitive deformation section 10 is increased, and accidental breakage of the outer packaging shell due to excessive shape change caused by heat transferred from the fusible section 32 can be suppressed.

[0138] The embodiments of this disclosure have been described above, but only typical examples have been exemplified. The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of this disclosure is not limited to the above-described embodiments, but is defined based on the claims. Furthermore, the technical scope of this disclosure includes the meaning equivalent to the scope of the claims and all modifications within that scope.

[0139] It should be noted that the effects described above are merely illustrative examples. Therefore, this disclosure is not limited to the matters described above, and additional effects may also be possible.

[0140] It should be noted that one embodiment of the present disclosure described above includes the following preferred embodiments.

[0141] <1> A battery pack comprising an outer packaging shell and a battery module housed within the outer packaging shell,

[0142] The outer packaging shell has a connector that is electrically connected to the battery module and a heat-sensitive deformable part positioned on the outer surface of the outer packaging shell.

[0143] The battery module includes a battery and tabs electrically connected to the battery and the connector.

[0144] The electrode tab has a fusible part.

[0145] The thermosensitive deformable part and the fusible part are connected in a manner that allows them to conduct heat to each other.

[0146] <2> According to the battery pack described in <1>,

[0147] The thermosensitive deformable part is disposed opposite to the fusible part in the thickness direction of the outer packaging shell.

[0148] <3> According to the battery pack described in <1> or <2>,

[0149] The thermosensitive deformable portion includes a recessed portion in which the thickness of the outer packaging shell is partially reduced.

[0150] <4> The battery pack according to any one of <1> to <3>,

[0151] The thermosensitive deformation part includes a wrinkled region.

[0152] <5> The battery pack described in <4>

[0153] The outer packaging shell also includes a non-wrinkled area on its outer surface that is adjacent to the wrinkled area of ​​the heat-sensitive deformable part.

[0154] <6> The battery pack according to any one of <1> to <5>,

[0155] The outer packaging shell has a concave region on the inner surface of the outer packaging shell in the area where the heat-sensitive deformable part is located.

[0156] <7> The battery pack according to any one of <1> to <6>,

[0157] Upon cross-sectional observation, the electrode tab has a convex portion protruding towards the outer packaging shell.

[0158] The fusible portion is located at the top of the convex-shaped portion.

[0159] <8> The battery pack described in <7>

[0160] The convex portion is capable of elastic deformation in the thickness direction of the outer packaging shell.

[0161] The convex portion is held between the battery and the outer packaging shell in an elastically compressed state.

[0162] <9> The battery pack according to any one of <1> to <8>,

[0163] The fusible portion is in contact with the inner surface of the outer packaging shell at a position opposite to the thermosensitive deformable portion.

[0164] <10> The battery pack according to any one of <1> to <9>,

[0165] The battery pack also includes a heat transfer section located between the thermosensitive deformable portion and the fusible portion.

[0166] The thermosensitive deformable part and the fusible part are connected via the heat transfer part in a manner that enables heat conduction.

[0167] <11> The battery pack according to <10>,

[0168] The heat transfer section has a first main surface and a second main surface that are opposite to each other.

[0169] The first main surface contacts the area on the inner surface of the outer packaging shell that is opposite to the heat-sensitive deformable part.

[0170] The second main surface is in contact with the fusible portion.

[0171] <12> The battery pack according to <10> or <11>,

[0172] Viewed from the thickness direction of the outer packaging shell, the outer edge of the heat transfer part is located on the outer side of the outer edge of the fusible part.

[0173] <13> The battery pack according to any one of <1> to <12>,

[0174] The outer packaging shell is made of resin material.

[0175] Industrial utilization potential

[0176] This disclosure can be appropriately used as a battery pack that allows external verification of the interruption status of the current path.

Claims

1. A battery pack comprising an outer packaging shell and a battery module housed within the outer packaging shell, The outer packaging shell has a connector that is electrically connected to the battery module and a heat-sensitive deformable part positioned on the outer surface of the outer packaging shell. The battery module includes a battery and tabs electrically connected to the battery and the connector. The electrode tab has a fusible part. The thermosensitive deformable part and the fusible part are connected in a manner that enables mutual thermal conduction.

2. The battery pack according to claim 1, wherein, The thermosensitive deformable part is disposed opposite to the fusible part in the thickness direction of the outer packaging shell.

3. The battery pack according to claim 1, wherein, The thermosensitive deformable portion includes a recessed portion in which the thickness of the outer packaging shell is partially reduced.

4. The battery pack according to claim 1, wherein, The thermosensitive deformation part includes a wrinkled region.

5. The battery pack according to claim 4, wherein, The outer packaging shell also includes a non-wrinkled area on its outer surface that is adjacent to the wrinkled area of ​​the heat-sensitive deformable part.

6. The battery pack according to claim 1, wherein, The outer packaging shell has a concave region on the inner surface of the outer packaging shell in the area where the heat-sensitive deformable part is located.

7. The battery pack according to claim 1, wherein, Upon cross-sectional observation, the electrode tab has a convex portion protruding towards the outer packaging shell. The fusible portion is located at the top of the convex-shaped portion.

8. The battery pack according to claim 7, wherein, The convex portion is capable of elastic deformation in the thickness direction of the outer packaging shell. The convex portion is held between the battery and the outer packaging shell in an elastically compressed state.

9. The battery pack according to claim 1, wherein, The fusible portion is in contact with the inner surface of the outer packaging shell at a position opposite to the thermosensitive deformable portion.

10. The battery pack according to claim 1, wherein, The battery pack also includes a heat transfer section located between the thermosensitive deformable portion and the fusible portion. The thermosensitive deformable part and the fusible part are connected via the heat transfer part in a manner that enables heat conduction.

11. The battery pack according to claim 10, wherein, The heat transfer section has a first main surface and a second main surface that are opposite to each other. The first main surface contacts the area on the inner surface of the outer packaging shell that is opposite to the heat-sensitive deformable part. The second main surface is in contact with the fusible portion.

12. The battery pack according to claim 10, wherein, Viewed from the thickness direction of the outer packaging shell, the outer edge of the heat transfer part is located on the outer side of the outer edge of the fusible part.

13. The battery pack according to claim 1, wherein, The outer packaging shell is made of resin material.

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