Apparatus comprising battery pack

Abstract

The technical idea of the present invention provides an apparatus comprising: a battery pack; and a mounting frame provided on the outside of the battery pack, wherein the battery pack includes: a pack frame mounted on the mounting frame; a cell assembly, which is provided in the inner space of the pack frame and which includes a battery cell; and a first buffer pad which is attached to the outer surface of the pack frame so as to be in contact with the mounting frame, and which includes a thermally expandable material.

Description

Device including a battery pack

[0001] The present invention relates to a device including a battery pack.

[0002] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2024-0071343, filed May 31, 2024, and all contents of the document in that Republic of Korea Patent Application are incorporated herein by reference.

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as a power source for various wireless devices, including handsets, laptops, and cordless vacuum cleaners. Recently, improved energy density and economies of scale have dramatically reduced the per-unit manufacturing cost of secondary batteries. Furthermore, as the range of battery electric vehicles (BEVs) has increased to match that of fuel-powered vehicles, the primary use of secondary batteries is shifting from mobile devices to mobility.

[0004] As secondary batteries become increasingly used in mobility, demand for their safety is increasing. Fires and other accidents involving secondary batteries used in mobility vehicles can endanger the lives of drivers, making research into technologies that enhance secondary battery safety essential.

[0005] The technical problem to be solved by the present invention is to provide a device including a battery pack.

[0006] In order to solve the above-described problem, the technical idea of ​​the present invention provides a device including a battery pack; and a mounting frame provided on the outside of the battery pack; wherein the battery pack includes: a pack frame mounted on the mounting frame; a cell assembly provided in an internal space of the pack frame and including a battery cell; and a first buffer pad attached to an outer surface of the pack frame so as to be in contact with the mounting frame and including a thermal foam material.

[0007] In exemplary embodiments, the first buffer pad is characterized in that it is configured to absorb shock between the mounting frame and the pack frame.

[0008] In exemplary embodiments, the first buffer pad is characterized by including: a base layer comprising a resin; and thermal foam particles provided within the base layer and containing the thermal foam material.

[0009] In exemplary embodiments, the pack frame comprises a base frame supporting the cell assembly; a top frame covering the cell assembly; and a side frame extending between the base frame and the top frame, wherein the first buffer pad is attached to the top frame.

[0010] In exemplary embodiments, the present invention further comprises a second buffer pad attached to at least one of the side frame and the base frame, the second buffer pad comprising a thermal foam material.

[0011] In exemplary embodiments, the pack frame further comprises an inner frame provided on one side of the cell assembly, wherein the first buffer pad is overlapped with the inner frame.

[0012] In exemplary embodiments, the pack frame comprises a base frame supporting the cell assembly; a top frame covering the cell assembly; and a side frame extending between the base frame and the top frame, wherein the first buffer pad is attached to the side frame.

[0013] In exemplary embodiments, the pack frame comprises a base frame supporting the cell assembly; a top frame covering the cell assembly; and a side frame extending between the base frame and the top frame; wherein the first buffer pad is attached to the base frame.

[0014] In exemplary embodiments, the first buffer pad is characterized by comprising a plurality of sub-pads spaced apart from each other along the outer surface of the pack frame.

[0015] In exemplary embodiments, the thermoplastic material is characterized by comprising expanded graphite.

[0016] In exemplary embodiments, the thermal foam material of the first buffer pad is characterized in that it is configured to foam above a foaming initiation temperature to form an insulating layer that fills a space between the mounting frame and the pack frame.

[0017] In exemplary embodiments, the device is characterized as being a vehicle including a driving wheel connected to the mounting frame.

[0018] According to exemplary embodiments of the present invention, the battery pack includes a buffer pad configured to absorb shock and vibration between the mounting frame and the pack frame of the battery pack, thereby preventing damage to the battery pack due to shock and vibration applied during assembly between the battery pack and the mounting frame or operation of a device including the battery pack.

[0019] According to exemplary embodiments of the present invention, a battery pack includes a buffer pad containing a thermal foam material, thereby preventing or suppressing heat generated in the battery pack in the event of a thermal event, such as ignition of a battery cell, from being transferred to the mounting frame and other parts of the device. Since heat generated in the battery pack can be prevented or suppressed from being transferred to the mounting frame and other parts of the device, the safety and reliability of the device including the battery pack can be improved.

[0020] The effects that can be obtained from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure pertain from the following description. In other words, unintended effects resulting from practicing the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0021] FIG. 1 is a cross-sectional view showing a device according to exemplary embodiments of the present invention.

[0022] FIG. 2 is a cross-sectional view schematically illustrating a portion of a first buffer pad according to exemplary embodiments of the present invention.

[0023] Figure 3 is a cross-sectional diagram schematically showing the device when a thermal event occurs in the battery pack.

[0024] FIG. 4 is a cross-sectional view schematically illustrating an assembly process between a battery pack and a mounting frame in exemplary embodiments of the present invention.

[0025] FIG. 5 is a plan view illustrating a battery pack according to exemplary embodiments of the present invention.

[0026] FIG. 6 is a cross-sectional view illustrating a device including a battery pack according to exemplary embodiments of the present invention.

[0027] FIG. 7 is a cross-sectional view illustrating a device including a battery pack according to exemplary embodiments of the present invention.

[0028] FIG. 8 is a cross-sectional view illustrating a device including a battery pack according to exemplary embodiments of the present invention.

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0030] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0031] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0032] Since the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or schematically illustrated for clearer explanation. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes or proportions.

[0033]

[0034] (Example 1)

[0035] FIG. 1 is a cross-sectional view showing a device (10) according to exemplary embodiments of the present invention.

[0036] Referring to FIG. 1, the device (10) may include a battery pack (100) and a mounting frame (200) provided outside the battery pack (100).

[0037] The battery pack (100) may include a pack frame (110), a cell assembly (120), and a first buffer pad (131).

[0038] The pack frame (110) can be mounted on the mounting frame (200). For example, the pack frame (110) can be fastened to the mounting frame (200) by a fastening member such as a bolt. The pack frame (110) can provide an internal space for accommodating a cell assembly (120). One or more cell assemblies (120) can be accommodated in the internal space of the pack frame (110). The pack frame (110) can include a base frame (111), a side frame (112), a top frame (113), and a plurality of internal frames (114).

[0039] A base frame (111) can support a cell assembly (120). The base frame (111) can have a flat plate shape extending in a first horizontal direction (e.g., X direction) and a second horizontal direction (e.g., Y direction). On the base frame (111), a plurality of cell assemblies (120) arranged in the first horizontal direction (e.g., X direction) and the second horizontal direction (e.g., Y direction) can be provided. In exemplary embodiments, the base frame (111) can include a cooling channel configured to allow a cooling fluid to flow.

[0040] A side frame (112) can be coupled to a base frame (111). The side frame (112) can extend along the perimeter of the base frame (111) and surround the cell assembly (120).

[0041] A top frame (113) may be fastened to the side frames (112) to cover a plurality of cell assemblies (120). The top frame (113) may have a flat plate shape extending in a first horizontal direction (e.g., X direction) and a second horizontal direction (e.g., Y direction). The top frame (113) may be spaced apart from the cell assemblies (120) with a venting space therebetween.

[0042] A plurality of inner frames (114) may be arranged on a base frame (111). The plurality of inner frames (114) may partition the inner space of the pack frame (110) into a plurality of accommodation spaces. The plurality of accommodation spaces of the pack frame (110) defined by the plurality of inner frames (114) may be partitioned in a first horizontal direction (e.g., X-direction) and / or a second horizontal direction (e.g., Y-direction), and one or more cell assemblies (120) may be arranged in each of the plurality of accommodation spaces of the pack frame (110) defined by the plurality of inner frames (114). In exemplary embodiments, the plurality of inner frames (114) may be spaced apart from each other in the first horizontal direction (e.g., X-direction), and individual inner frames (114) may extend in the second horizontal direction (e.g., Y-direction). One cell assembly (120) may be arranged between a pair of inner frames (114). Each inner frame (114) can contact the side of the cell assembly (120).

[0043] The cell assembly (120) can be mounted on a base frame (111). The cell assembly (120) can include a plurality of battery cells (121).

[0044] An individual battery cell (121) is a basic unit of a lithium ion battery, i.e., a secondary battery. An individual battery cell (121) may include an electrode assembly, an electrolyte, and a cell case. The electrode assembly built into the cell case may include a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The electrode assembly may be either a jelly-roll type or a stack type depending on the assembly form. A jelly-roll type electrode assembly may include a winding structure of a positive electrode, a negative electrode, and a separator interposed therebetween. A stack type electrode assembly may include a plurality of sequentially stacked positive electrodes, a plurality of negative electrodes, and a plurality of separators interposed therebetween. The positive electrode may include a positive electrode current collector and a positive electrode active material. The negative electrode may include a negative electrode current collector and an negative electrode active material.

[0045] Each battery cell (121) may be a pouch-type battery cell, a cylindrical battery cell, or a square battery cell. The electrode assembly of the pouch-type battery cell is housed in a pouch case including an aluminum laminate sheet. The electrode assembly of the cylindrical battery cell is housed in a cylindrical metal can. The electrode assembly of the square battery cell is housed in a square metal can.

[0046] A plurality of battery cells (121) provided in the cell assembly (120) may be connected in series and / or in parallel. For example, a plurality of battery cells (121) may be connected in series with each other. For example, a plurality of battery cells (121) may also be connected in parallel with each other. For example, when a set of two or more battery cells (121) connected in parallel with each other is defined as a bank, one bank composed of two or more battery cells (121) connected in parallel with each other and another bank composed of two or more battery cells (121) connected in parallel with each other may be connected in series.

[0047] In exemplary embodiments, a plurality of battery cells (121) provided in a cell assembly (120) may be arranged in a first horizontal direction (e.g., X direction), and individual battery cells (121) may extend in a second horizontal direction (e.g., Y direction). An electrode lead may be provided at at least one of both ends of an individual battery cell (121) along the second horizontal direction (e.g., Y direction). Electrode leads of neighboring battery cells (121) among the plurality of battery cells (121) may be electrically and physically connected to each other.

[0048] A plurality of battery cells (121) provided in the cell assembly (120) may be attached to the base frame (111) by a thermally conductive adhesive layer. The thermally conductive adhesive layer may include, for example, a thermal resin and / or a thermal interface material.

[0049] The cell assembly (120) may include a busbar frame connected to the side of a plurality of battery cells (121). A busbar frame may be arranged at each of the two ends of the cell assembly (120) along a second horizontal direction (e.g., Y direction). The busbar frame may support the busbars and the electrode leads of the battery cells (121). The busbars may be electrically and physically connected to at least one of the electrode leads of the plurality of battery cells (121). The busbar may be joined to at least one of the electrode leads of the plurality of battery cells (121) by welding.

[0050] The first buffer pad (131) may be attached to the pack frame (110). For example, the first buffer pad (131) may be attached to an outer surface of the pack frame (110) facing the mounting frame (200). The first buffer pad (131) may extend along the outer surface of the pack frame (110) and may have a generally uniform thickness. The first buffer pad (131) may be a single pad or may include a plurality of sub-pads spaced apart from each other. The first buffer pad (131) may contact each of the pack frame (110) and the mounting frame (200). The first buffer pad (131) may be configured to absorb shock and vibration between the mounting frame (200) and the pack frame (110) by including an elastic material such as a polyurethane resin, a silicone resin, or rubber. The first buffer pad (131) can prevent or suppress damage to the battery pack (100) caused by shock and vibration by alleviating shock and vibration applied to the pack frame (110) through the mounting frame (200).

[0051] The first buffer pad (131) may be configured to prevent heat generated in the battery pack (100) from being transferred to the mounting frame (200) when a thermal event, such as ignition of a battery cell (121) within the battery pack (100), occurs. The first buffer pad (131) may include a thermal foam material. The thermal foam material of the first buffer pad (131) may be configured to have fire resistance and to expand in volume above a specific temperature. When a thermal event occurs in the battery pack (100), the thermal foam material of the first buffer pad (131) may be foamed above a foaming initiation temperature, and the expanded thermal foam material may form an insulating layer that fills a gap between the battery pack (100) and the mounting frame (200). The insulating layer formed from the thermal foam material may thermally isolate the battery pack (100) and the mounting frame (200).

[0052] In exemplary embodiments, the first buffer pad (131) may be attached to an outer surface of the top frame (113) facing the mounting frame (200). When a thermal event occurs in the battery pack (100), the thermal foam material of the first buffer pad (131) may form an insulating layer between the top frame (113) and the mounting frame (200).

[0053] In exemplary embodiments, the thermal foam material of the first buffer pad (131) may include expanded graphite, vermiculite, or a combination thereof.

[0054] In exemplary embodiments, the thermal foaming material of the first buffer pad (131) may be configured to foam at a foaming initiation temperature or higher, thereby expanding in volume by between 10 and 50 times. The foaming initiation temperature may be 100°C or higher, 200°C or higher, 300°C or higher, 400°C or higher, or 500°C or higher.

[0055] FIG. 2 is a cross-sectional view schematically showing a portion of a first buffer pad (131) according to exemplary embodiments of the present invention.

[0056] Referring to FIGS. 1 and 2, the first buffer pad (131) may include a base layer (141) and thermal foam particles (142) contained within the base layer (141). The base layer (141) may include an elastic material. For example, the base layer (141) may include a resin, such as a polyurethane resin, a silicone resin, or a combination thereof. The thermal foam particles (142) may include a thermal foam material, such as expanded graphite, vermiculite, or a combination thereof.

[0057] FIG. 3 is a cross-sectional view schematically showing the device (10) when a thermal event occurs in the battery pack (100).

[0058] Referring to FIG. 3, when a thermal event such as ignition of a battery cell (121) occurs in the battery pack (100), the thermal foam material of the first buffer pad (131) provided between the pack frame (110) and the mounting frame (200) expands, and the expanded thermal foam material can form an insulating layer (139) that at least partially fills the space between the pack frame (110) and the mounting frame (200). Since the thermal transfer between the battery pack (100) and the mounting frame (200) can be prevented or suppressed by the thermal insulation layer (139), the safety and reliability of the device (10) including the battery pack (100) can be improved.

[0059] FIG. 4 is a cross-sectional view schematically showing an assembly process between a battery pack (100) and a mounting frame (200) in exemplary embodiments of the present invention.

[0060] Referring to FIG. 4, when assembling the battery pack (100) to the mounting frame (200), the pack frame (110) can be fastened to the mounting frame (200) using a fastening member such as a bolt. The first buffer pad (131) has elasticity and its thickness can be reduced by an external force applied during the assembly between the battery pack (100) and the mounting frame (200). Referring to FIG. 1 and FIG. 4, when the assembly between the battery pack (100) and the mounting frame (200) is completed, the thickness of the first buffer pad (131) can be smaller than the initial thickness of the first buffer pad (131) before assembling the battery pack (100) and the mounting frame (200). The first buffer pad (131) absorbs the shock applied to the pack frame (110) during the process of assembling the pack frame (110) to the mounting frame (200), thereby preventing damage to the battery pack (100) during the process of assembling the pack frame (110) and the mounting frame (200).

[0061] FIG. 5 is a plan view showing a battery pack (100) according to exemplary embodiments of the present invention.

[0062] Referring to FIG. 5 together with FIG. 1, in the battery pack (100), a first buffer pad (131) may be attached to a top frame (113). The first buffer pad (131) may partially cover an upper surface of the top frame (113) facing the mounting frame (200). In exemplary embodiments, the first buffer pad (131) may extend in a first horizontal direction (e.g., X direction) and / or a second horizontal direction (e.g., Y direction) on the top frame (113). In exemplary embodiments, the first buffer pad (131) may be arranged to overlap an inner frame (114) or a side frame (112) in a vertical direction (e.g., Z direction). When the first buffer pad (131) is at least partially overlapped in the vertical direction (e.g., in the Z direction) on the inner frame (114) or the side frame (112), when an insulating layer is created by thermal expansion of the thermal foam material of the first buffer pad (131), the inner frame (114) or the side frame (112) can support the top frame (113) to suppress deformation of the top frame (113) due to external force generated while the insulating layer is rapidly created.

[0063]

[0064] (Example 2)

[0065] FIG. 6 is a cross-sectional view illustrating a device (10A) including a battery pack (100A) according to exemplary embodiments of the present invention. Below, the device (10A) illustrated in FIG. 6 will be described, focusing on differences from the device (10) described with reference to FIG. 1.

[0066] Referring to FIG. 6, the battery pack (100A) may include a first buffer pad (131) attached to a top frame (113) and a second buffer pad (132) attached to a side frame (112).

[0067] The second buffer pad (132) may be configured to contact each of the mounting frame (200) and the side frame (112) and to absorb shock and vibration between the mounting frame (200) and the side frame (112). The second buffer pad (132) may include a thermal foam material. For example, the second buffer pad (132) may include a base layer (141) and thermal foam particles. The material of the base layer (141) of the second buffer pad (132) may be substantially the same as the material of the base layer (141) of the first buffer pad (131), and the material of the thermal foam particles of the second buffer pad (132) may be substantially the same as the material of the thermal foam particles of the first buffer pad (131).

[0068] In some exemplary embodiments, the battery pack includes a second buffer pad (132), but the first buffer pad (131) may be omitted from the battery pack.

[0069] When a thermal event occurs in the battery pack (100A), the thermal foam material of the first buffer pad (131) can form an insulating layer filling between the mounting frame (200) and the top frame (113), and the thermal foam material of the second buffer pad (132) can form an insulating layer filling between the mounting frame (200) and the side frame (112). Since heat transfer between the battery pack (100A) and the mounting frame (200) is prevented or suppressed by the insulating layer formed from the thermal foam material of the first buffer pad (131) and the insulating layer formed from the thermal foam material of the second buffer pad (132), the safety and reliability of the device (10A) including the battery pack (100A) can be improved.

[0070]

[0071] (Example 4)

[0072] FIG. 7 is a cross-sectional view illustrating a device (10B) including a battery pack (100B) according to exemplary embodiments of the present invention. Below, the device (10B) illustrated in FIG. 7 will be described, focusing on differences from the device (10A) described with reference to FIG. 6 .

[0073] Referring to FIG. 7, the battery pack (100B) may include a first buffer pad (131) attached to a top frame (113), a second buffer pad (132) attached to a side frame (112), and a third buffer pad (133) attached to a base frame (111).

[0074] The third buffer pad (133) may be configured to contact each of the mounting frame (200) and the base frame (111), and to absorb shock and vibration between the mounting frame (200) and the base frame (111). The third buffer pad (133) may include a thermal foam material. For example, the third buffer pad (133) may include a base layer and thermal foam particles. The material of the base layer of the third buffer pad (133) may be substantially the same as the material of the base layer of the first buffer pad (131), and the material of the thermal foam particles of the third buffer pad (133) may be substantially the same as the material of the thermal foam particles of the first buffer pad (131).

[0075] In some exemplary embodiments, the battery pack includes a second buffer pad (132) and a third buffer pad (133), but the first buffer pad (131) may be omitted from the battery pack. Alternatively, in some exemplary embodiments, the battery pack includes a third buffer pad (133), but the first buffer pad (131) and the second buffer pad (132) may be omitted from the battery pack.

[0076] When a thermal event occurs in the battery pack (100B), the thermal foam material of the first buffer pad (131) can form an insulating layer filling between the mounting frame (200) and the top frame (113), the thermal foam material of the second buffer pad (132) can form an insulating layer filling between the mounting frame (200) and the side frame (112), and the thermal foam material of the third buffer pad (133) can form an insulating layer filling between the mounting frame (200) and the base frame (111). Since heat transfer between the battery pack (100B) and the mounting frame (200) is prevented or suppressed by the insulating layer formed from the thermal foam material of the first buffer pad (131), the insulating layer formed from the thermal foam material of the second buffer pad (132), and the insulating layer formed from the thermal foam material of the third buffer pad (133), the safety and reliability of the device (10B) including the battery pack (100B) can be improved.

[0077]

[0078] (Example 5)

[0079] FIG. 8 is a cross-sectional view showing a device (10C) including a battery pack (100) according to exemplary embodiments of the present invention.

[0080] Referring to FIG. 8, the device (10C) may be a vehicle such as an electric vehicle. The device (10C) may include a mounting frame (200), a battery pack (100) mounted on the mounting frame (200), and driving wheels (220) mounted on the mounting frame (200). In FIG. 8, only a portion of the vehicle configuration is illustrated for clarity. The mounting frame (200) may further include a portion covering the upper side and / or the side of the battery pack (100), and a cabin room for passengers to board may be provided on the upper side of the battery pack (100).

[0081] According to exemplary embodiments of the present invention, the battery pack (100) includes a buffer pad configured to absorb shock and vibration between the mounting frame (200) and the pack frame (110) of the battery pack (100), so that damage to the battery pack (100) due to shock and vibration applied during assembly between the battery pack (100) and the mounting frame (200) or operation of the device (10C) including the battery pack (100) can be prevented.

[0082] According to exemplary embodiments of the present invention, since the battery pack (100) includes a buffer pad containing a thermal foam material, heat generated in the battery pack (100) in the event of a thermal event, such as ignition of a battery cell (121), can be prevented or suppressed from being transferred to the mounting frame (200) and other parts of the device (10C). Since heat generated in the battery pack (100) can be prevented or suppressed from being transferred to the mounting frame (200) and other parts of the device (10C), the safety and reliability of the device (10C) including the battery pack (100) can be improved.

[0083] The present invention has been described in more detail through drawings and examples. However, the configurations described in the drawings or examples described in this specification are merely embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

Claims

1. Battery pack; and A mounting frame provided on the outside of the above battery pack; Including, The above battery pack, A pack frame mounted on the above mounting frame; A cell assembly provided in the internal space of the pack frame and including a battery cell; and A first buffer pad attached to the outer surface of the pack frame so as to be in contact with the mounting frame, the first buffer pad including a thermal foam material; A device comprising:

2. In paragraph 1, A device characterized in that the first buffer pad is configured to absorb shock between the mounting frame and the pack frame.

3. In paragraph 1, The above first buffer pad, a base layer comprising a resin; and Thermal foam particles provided within the base layer and containing the thermal foam material; A device characterized by including:

4. In paragraph 1, The above pack frame is, A base frame supporting the above cell assembly; a top frame covering the above cell assembly; and A side frame extending between the base frame and the top frame; Including, A device characterized in that the first buffer pad is attached to the top frame.

5. In paragraph 4, A device characterized in that it further comprises a second buffer pad attached to at least one of the side frame and the base frame and comprising a thermal foam material.

6. In paragraph 4, The above pack frame further includes an internal frame provided on one side of the cell assembly, A device characterized in that the first buffer pad is overlapped with the inner frame.

7. In paragraph 1, The above pack frame is, A base frame supporting the above cell assembly; a top frame covering the above cell assembly; and A side frame extending between the base frame and the top frame; Including, A device characterized in that the first buffer pad is attached to the side frame.

8. In paragraph 1, The above pack frame is, A base frame supporting the above cell assembly; a top frame covering the above cell assembly; and A side frame extending between the base frame and the top frame; Including, A device characterized in that the first buffer pad is attached to the base frame.

9. In paragraph 1, A device characterized in that the first buffer pad comprises a plurality of sub-pads spaced apart from each other along the outer surface of the pack frame.

10. In paragraph 1, A device characterized in that the above-mentioned thermal foaming material comprises expanded graphite.

11. In paragraph 1, A device characterized in that the thermal foam material of the first buffer pad is foamed at a temperature higher than the foaming initiation temperature to form an insulating layer that fills the space between the mounting frame and the pack frame.

12. In paragraph 1, A device characterized in that the device is a vehicle including a driving wheel connected to the mounting frame.

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