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US-20260128450-A1 - BATTERY PACK

US20260128450A1US 20260128450 A1US20260128450 A1US 20260128450A1US-20260128450-A1

Abstract

A battery pack includes a battery; a heat absorbing member that includes a heat absorbing agent and a container accommodating the heat absorbing agent; and a thermal expansion member that is interposed between the battery and the heat absorbing member.

Inventors

  • Etsuko HONDA

Assignees

  • MURATA MANUFACTURING CO., LTD.

Dates

Publication Date
20260507
Application Date
20251230
Priority Date
20230915

Claims (18)

  1. 1 . A battery pack comprising: a battery; a heat absorbing member that includes a heat absorbing agent and a container accommodating the heat absorbing agent; and a thermal expansion member that is interposed between the battery and the heat absorbing member.
  2. 2 . The battery pack according to claim 1 , wherein the heat absorbing member is provided at a position adjacent to the battery, the container has a first surface facing an outer surface of the battery, and the thermal expansion member is provided between the battery and the first surface.
  3. 3 . The battery pack according to claim 1 , wherein the battery is arranged such that a plurality of the batteries are adjacent to each other, the heat absorbing member is provided at a position adjacent to the plurality of batteries, the container has a first surface facing an outer surface of one battery and a second surface facing an outer surface of another battery, and the thermal expansion members are provided between the one battery and the first surface and between the other battery and the second surface.
  4. 4 . The battery pack according to claim 3 , wherein the battery has a cylindrical shape, the first surface extends along an outer peripheral surface of the one battery, the second surface extends along an outer peripheral surface of the other battery, the thermal expansion member provided between the one battery and the first surface is in contact with the outer peripheral surface of the one battery and the first surface, and the thermal expansion member provided between the other battery and the second surface is in contact with the outer peripheral surface of the other battery and the second surface.
  5. 5 . The battery pack according to claim 4 , wherein the container includes a resin layer, and a first joint where a resin layer on one end side of the first surface and a resin layer on one end side of the second surface are joined.
  6. 6 . The battery pack according to claim 5 , wherein the first joint is arranged in an inter-battery space between the one battery and the other battery.
  7. 7 . The battery pack according to claim 5 , wherein the container further includes a metal layer.
  8. 8 . The battery pack according to claim 4 , wherein the container includes a resin layer, and the container has a third surface having one end joined to another end of the first surface and another end joined to another end of the second surface, and a first end joint where a resin layer on one end side of the third surface and a resin layer on another end side of the first surface are joined.
  9. 9 . The battery pack according to claim 8 , wherein a second end joint where the resin layer on the other end side of the third surface and the resin layer on one end side of the second surface are joined is provided.
  10. 10 . The battery pack according to claim 4 , wherein the container includes a resin layer and a metal layer provided outside the resin layer, and a first joint where a resin layer on one end side of the first surface and a resin layer on one end side of the second surface are joined, has a third surface having one end joined to one end of the first surface and another end joined to one end of the second surface, includes a first end joint where a resin layer on one end side of the third surface and a resin layer on another end side of the first surface are joined, and a second end joint where a resin layer on another end side of the third surface and a resin layer on another end side of the second surface are joined, and at least one of the first joint, the first end joint, or the second end joint is arranged in an inter-battery space between the one battery and the other battery.
  11. 11 . The battery pack according to claim 5 , wherein the container has a first facing surface that faces the first surface, and a second facing surface that faces the second surface, and includes a second joint where a resin layer on another end side of the first surface and a resin layer on another end side of the second facing surface are joined, a third joint where a resin layer on one end side of the first facing surface and a resin layer on one end side of the second facing surface are joined, and a fourth joint where a resin layer on another end side of the second surface and a resin layer on another end side of the first facing surface are joined.
  12. 12 . The battery pack according to claim 5 , wherein the thermal expansion member is provided at a position excluding the first joint.
  13. 13 . The battery pack according to claim 1 , wherein the container has a columnar shape having a triangular sectional shape.
  14. 14 . The battery pack according to claim 1 , wherein the container has a columnar shape having a quadrangular sectional shape.
  15. 15 . The battery pack according to claim 3 , wherein the thermal expansion member provided between the one battery and the first surface is provided on an entire surface of the first surface, and the thermal expansion member provided between the other battery and the second surface is provided on an entire surface of the second surface.
  16. 16 . The battery pack according to claim 3 , wherein the thermal expansion member provided between the one battery and the first surface is provided on a part of the first surface, and the thermal expansion member provided between the other battery and the second surface is provided on a part of the second surface.
  17. 17 . The battery pack according to claim 3 , wherein a plurality of the thermal expansion members provided between the one battery and the first surface are provided, and the thermal expansion members are spaced apart from each other in a direction in which a central axis of the battery extends, and a plurality of the thermal expansion members provided between the other battery and the second surface are provided, and the thermal expansion members are spaced apart from each other in the direction in which the central axis of the battery extends.
  18. 18 . The battery pack according to claim 1 , wherein the thermal expansion member contains a resin material.

Description

CROSS REFERENCE TO RELATED APPLICATIONS The present application is a continuation of International Application No. PCT/JP2024/023389, filed on Jun. 27, 2024, which claims priority to Japanese Patent Application No. 2023-150373, filed on Sep. 15, 2023, the entire contents of which are incorporated herein by reference. BACKGROUND The present disclosure relates to a battery pack. A battery module includes a battery unit including two or more battery cells, a housing, a lid, and a heat absorbing member, in which the heat absorbing member is provided in contact with a side surface of the battery unit and contains a heat absorbing agent having liquid or gel-like fluid. Then, in the battery module described above, in a case where one of the battery cells constituting the battery unit has abnormally generated heat, a part of the heat absorbing member is opened, and the heat absorbing agent inside the heat absorbing member adheres to the battery cell, thereby lowering a temperature of the battery cell that has abnormally generated heat. SUMMARY The present disclosure relates to a battery pack. However, depending on a position where the heat absorbing member is opened or an opening shape, the heat absorbing agent may remain in the heat absorbing member, and an amount of the heat absorbing agent adhering to the battery may be reduced. In this regard, a main object of the present disclosure is to provide a battery pack capable of more appropriately causing a heat absorbing agent to adhere to a battery in a case where the battery has abnormally generated heat. A battery pack according to an embodiment of the present disclosure includes: a battery;a heat absorbing member that includes a heat absorbing agent and a container accommodating the heat absorbing agent; anda thermal expansion member that is interposed between the battery and the heat absorbing member. According to an embodiment of the present disclosure, in a case where the battery has abnormally generated heat, it is possible to more appropriately cause the heat absorbing agent to adhere to the battery. Specifically, since the thermal expansion member is interposed between the battery and the heat absorbing member, the thermal expansion member is expanded by heat generation of the battery, a stress caused by the expansion acts on the heat absorbing member, more heat absorbing agent can be released to outside of the container, and the released heat absorbing agent adheres to the battery to cool the battery, so that a temperature rise of the battery can be suppressed. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a schematic exploded perspective view of a battery pack. FIG. 2 is a schematic perspective view of a heat absorbing member of an embodiment. FIG. 3 is a schematic sectional view of a battery module of an embodiment. FIG. 4 is a schematic sectional view when abnormal heat generation occurs in the battery module of an embodiment. FIG. 5 is a schematic sectional view of a battery module of an embodiment. FIG. 6 is a schematic sectional view when abnormal heat generation occurs in the battery module of an embodiment. FIG. 7A is a schematic sectional view of a modification of a heat absorbing member of an embodiment. FIG. 7B is a schematic sectional view of a modification of the heat absorbing member of an embodiment. FIG. 8A is a schematic perspective view of a modification of a thermal expansion member. FIG. 8B is a schematic perspective view of a modification of the thermal expansion member. FIG. 8C is a schematic perspective view of a modification of the thermal expansion member. FIG. 9A is a schematic perspective view of a modification of the thermal expansion member. FIG. 9B is a schematic perspective view of a modification of the thermal expansion member. FIG. 9C is a schematic perspective view of a modification of the thermal expansion member. DETAILED DESCRIPTION The present disclosure will be described in more detail including with reference to the drawings according to an embodiment. Although description will be made with reference to the drawings as necessary, various elements in the drawings are merely schematically and exemplarily illustrated for understanding of the present disclosure, and appearance, a dimensional ratio, and the like can be different from those of actual ones. Various numerical ranges referred to herein are intended to include lower limit and upper limit numerical values themselves, unless otherwise noted, such as “less than” or “greater than/larger than”. When a numerical range such as 1 to 10 is taken as an example, it can be interpreted as including the lower limit of “1” and also including the upper limit of “10”. The terms “about” and “degree” mean that they may include variations of a few percent, e.g., ±10%. The term “planar view” in the present description refers to a state when an object (for example, a battery pack) is placed and viewed from directly above its thickness (height) direction, and has the same meaning as pl