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EP-4184689-B1 - BATTERY CELL, COVER ASSEMBLY, BATTERY, ELECTRIC APPARATUS, METHOD, AND DEVICE

EP4184689B1EP 4184689 B1EP4184689 B1EP 4184689B1EP-4184689-B1

Inventors

  • MENG, Wanqiu
  • LIU, QIAN
  • YE, Yonghuang
  • ZHENG, YULIAN
  • XUE, Longfei
  • ZHANG, XIAOXI
  • WANG, PENG

Dates

Publication Date
20260513
Application Date
20210928

Claims (15)

  1. A battery cell (20), comprising: an electrode assembly (23); a housing, configured to accommodate the electrode assembly (23), wherein a wall portion (210) of the housing comprises a body portion (211) and a fastener (212), the fastener (212) is provided with a recess (2121) communicating with an outside, and the recess (2121) is arranged on an inner surface of the fastener (212) facing the electrode assembly (23) and recessed in a direction leaving the electrode assembly (23); and an air-permeable member (25) covering the recess (2121), wherein the air-permeable member (25) is configured to allow gas to be discharged to the outside of the housing through the recess (2121) when a gas pressure inside the housing reaches a threshold; wherein a bottom wall (2121a) of the recess (2121) is provided with a protruding portion (2122) extending toward the electrode assembly (23), and the protruding portion (2122) is configured to be attached to the air-permeable member (25), so as to limit deformation of the air-permeable member (25) in a thickness direction (X) of the wall portion (210), wherein an accommodating cavity (2124) communicating with the outside is formed between an outer peripheral wall (2122c) of the protruding portion (2122) and an inner peripheral wall (2121b) of the recess (2121), the bottom wall (2121a) of the recess (2121) is provided with a first through hole (2123), and the first through hole (2123) is configured to allow gas circulation with an inner space of the battery cell (20) through the accommodating cavity (2124).
  2. The battery cell (20) according to claim 1, wherein the first through hole (2123) is provided in plurality, and the plurality of first through holes (2123) are spaced apart.
  3. The battery cell (20) according to claim 1 or 2, wherein the protruding portion (2122) comprises a first protrusion (2122a), and the accommodating cavity (2124) communicating with the outside is formed between an outer peripheral wall (2122c) of the first protrusion (2122a) and the inner peripheral wall (2121b) of the recess (2121); or the protruding portion (2122) comprises a first protrusion (2122a) and a second protrusion (2122b), the second protrusion (2122b) surrounds the first protrusion (2122a) and is spaced apart from the first protrusion (2122a), the accommodating cavity (2124) communicating with the outside is formed between an outer peripheral wall (2122c) of the first protrusion (2122a) and an inner peripheral wall (2121b) of the second protrusion (2122b), and the accommodating cavity (2124) communicating with the outside is formed between an outer peripheral wall (2122c) of the second protrusion (2122b) and the inner peripheral wall (2121b) of the recess (2121), and optionally, two or more second protrusions (2122b) are provided, the two or more second protrusions (2122b) are coaxially spaced apart, and the accommodating cavity (2124) communicating with the outside is formed between two adjacent second protrusions (2122b).
  4. The battery cell (20) according to any one of claims 1 to 3, wherein the body portion (211) comprises a second through hole (2111), the second through hole (2111) is configured to accommodate the fastener (212), and the fastener (212) is configured to connect the air-permeable member (25) and the body portion (211).
  5. The battery cell (20) according to claim 4, the second through hole (2111) comprises a first hole section (2111a) and a second hole section (2111b) in an axial direction of the second through hole (2111), a radial dimension of the first hole section (2111a) is greater than a radial dimension of the second hole section (2111b), a transition surface (2111c) is connected between the first hole section (2111a) and the second hole section (2111b), and the transition surface (2111c) is configured to support the fastener (212), wherein the axial direction is parallel to the thickness direction (X) of the wall portion (210).
  6. The battery cell (20) according to claim 4 or 5, wherein the second hole section (2111b) is located between the first hole section (2111a) and the electrode assembly (23), and in the axial direction, a surface of the fastener (212) facing the electrode assembly (23) abuts against the transition surface (2111c); or wherein the first hole section (2111a) is located between the second hole section (2111b) and the electrode assembly (23), a surface of the fastener (212) facing away from the electrode assembly (23) abuts against the transition surface (2111c), and in the axial direction, an orthographic projection of each first through hole (2123) is located within an orthographic projection of a hole wall of the second hole section (2111b); or wherein the first hole section (2111a) is located between the second hole section (2111b) and the electrode assembly (23), a surface of the fastener (212) facing away from the electrode assembly (23) abuts against the transition surface (2111c), the second through hole (2111) further comprises a third hole section (2111d), the third hole section (2111d) being formed by extending in the axial direction from the transition surface (2111c) to a side facing away from the first hole section (2111a), and a radial dimension of the third hole section (2111d) being smaller than the radial dimension of the first hole section (2111a) but greater than the radial dimension of the second hole section (2111b), and in the axial direction, an orthographic projection of each first through hole (2123) is located within an orthographic projection of a hole wall of the third hole section (2111d).
  7. The battery cell (20) according to any one of claims 1 to 6, wherein the fastener (212) comprises a connecting portion (212a) and a mounting portion (212b), the connecting portion (212a) being connected to and protruding out of an outer side wall of the mounting portion (212b), the connecting portion (212a) being configured to connect the body portion (211), and the mounting portion (212b) being configured to connect the air-permeable member (25), optionally, the connecting portion (212a) is welded to the body portion (211), and in the thickness direction (X), the mounting portion (212b) protrudes out of the connecting portion (212a) on a side where the electrode assembly (23) is located, and the air-permeable member (25) is connected to an end surface of the mounting portion (212b) facing the electrode assembly (23).
  8. The battery cell (20) according to claim 7, wherein a gap (2125) is formed between the outer side wall of the mounting portion (212b) and a hole wall of the second through hole (2111), so that the air-permeable member (25) and the hole wall of the second through hole (2111) are spaced apart.
  9. The battery cell (20) according to any one of claims 1 to 8, wherein a support member (26) is provided in the accommodating cavity (2124), the support member (26) is configured to support the air-permeable member (25), and the gas is able to flow through the support member (26) and be discharged from the first through hole (2123), optionally, the support member (26) is connected, through a chemical bond, to a wall surface that forms the accommodating cavity (2124) via enclosing.
  10. The battery cell (20) according to any one of claims 1 to 9, wherein the air-permeable member (25) is connected to an end surface of the protruding portion (2122) through a chemical bond.
  11. The battery cell (20) according to any one of claims 1 to 10, wherein the housing has a housing body (22) and a cover assembly (21), the housing body (22) has an opening, the cover assembly (21) is provided for covering the opening, and one of the housing body (22) and the cover assembly (21) comprises the wall portion (210).
  12. The battery cell (20) according to claim 11, wherein the cover assembly (21) comprises the wall portion (210), and the battery cell (20) further comprises an insulator (24), the insulator (24) being configured to separate the cover assembly (21) from the electrode assembly (23), the insulator (24) being provided with a third through hole (241), and the third through hole (241) being configured to communicate with the recess (2121), optionally, the third through hole (241) is provided in plurality, and the plurality of third through holes (241) are spaced apart.
  13. A battery (100), comprising the battery cell (20) according to any one of claims 1 to 12.
  14. A method for preparing battery cell, comprising: providing (S100) a housing body, wherein the housing body has an opening; providing (S200) an electrode assembly and placing the electrode assembly in the housing body; and providing (S300) a cover assembly and covering the opening with the cover assembly to form the battery cell, wherein the cover assembly comprises a cover plate and an air-permeable member, a wall portion of the cover plate comprising a body portion and a fastener, wherein the fastener is provided with a recess communicating with an outside, and the recess is arranged on an inner surface of the fastener facing the electrode assembly and recessed in a direction leaving the electrode assembly; and the air-permeable member covers the recess and is configured to allow gas to be discharged to the outside of the battery cell through the recess when a gas pressure inside the battery cell reaches a threshold; wherein a bottom wall of the recess is provided with a protruding portion extending toward the electrode assembly, and the protruding portion is configured to be attached to the air-permeable member, so as to limit deformation of the air-permeable member in a thickness direction of the wall portion; the method further comprising forming an accommodating cavity (2124) between an outer peripheral wall (2122c) of the protruding portion (2122) and an inner peripheral wall (2121b) of the recess (2121), the accommodating cavity (2124) communicating with the outside, the bottom wall (2121a) of the recess (2121) is provided with a first through hole (2123), and the first through hole (2123) is configured to allow gas circulation with an inner space of the battery cell (20) through the accommodating cavity (2124).
  15. A device for preparing battery cell (20), comprising: a first assembling apparatus, configured to provide a housing body (22), wherein the housing body (22) has an opening; a second assembling apparatus, configured to provide an electrode assembly (23) and place the electrode assembly (23) in the housing body (22); and a third assembling apparatus, configured to provide a cover assembly (21) and cover the opening with the cover assembly (21) to form the battery cell (20), wherein the cover assembly (21) comprises a cover plate (21b) and an air-permeable member (25), a wall portion (210) of the cover plate (21b) comprising a body portion (211) and a fastener (212), wherein the fastener (212) is provided with a recess (2121) communicating with an outside, and the recess (2121) is arranged on an inner surface of the fastener (212) facing the electrode assembly (23) and recessed in a direction leaving the electrode assembly (23); and the air-permeable member (25) covers the recess (2121) and is configured to allow gas to be discharged to the outside of the battery cell (20) through the recess (2121) when a gas pressure inside the battery cell (20) reaches a threshold; wherein a bottom wall (2121a) of the recess (2121) is provided with a protruding portion (2122) extending toward the electrode assembly (23), and the protruding portion (2122) is configured to be attached to the air-permeable member (25), so as to limit deformation of the air-permeable member (25) in a thickness direction (X) of the wall portion (210); and wherein an accommodating cavity (2124) communicating with the outside is formed between an outer peripheral wall (2122c) of the protruding portion (2122) and an inner peripheral wall (2121b) of the recess (2121), the bottom wall (2121a) of the recess (2121) is provided with a first through hole (2123), and the first through hole (2123) is configured to allow gas circulation with an inner space of the battery cell (20) through the accommodating cavity (2124).

Description

TECHNICAL FIELD This application relates to the field of battery technologies, and in particular, to a battery cell, a cover assembly, a battery, an electric apparatus, a method, and a device. BACKGROUND Rechargeable battery cells have been widely used in electric vehicles due to the advantages of high energy density, high power density, long cycle life, long storage time, and the like. Currently, the safety of gas discharge of battery cells is constraining the development of battery cells, and therefore technology related to safety performance of battery cells has become one of the subjects of research. CN112467300A relates to an explosion-proof combination valve which comprises an explosion-proof cavity provided with a through hole, an outer explosion-proof sheet arranged above the through hole, and an inner explosion-proof sheet arranged below the through hole; the explosion-proof cavity, the outer explosion-proof sheet and the inner explosion-proof sheet form a closed space for accommodating an explosion-proof material, the explosion-proof material is accommodated in the closed space, and the inner explosion-proof sheet is broken under set conditions to release the explosion-proof material into the battery. SUMMARY Embodiments of this application provide a battery cell, a cover assembly, a battery, an electric apparatus, a method, and a device, as defined in the appended claims. The battery cell can alleviate battery safety problems caused by gas discharge. According to a first aspect, this application provides a battery cell, including an electrode assembly, a housing, and an air-permeable member. The housing is configured to accommodate the electrode assembly, where a wall portion of the housing includes a body portion and a fastener, the fastener is provided with a recess communicating with the outside, and the recess is arranged on an inner surface of the fastener facing the electrode assembly and recessed in a direction leaving the electrode assembly. The air-permeable member covers the recess and is configured to allow gas to be discharged to the outside of the housing through the recess when a gas pressure inside the housing reaches a threshold. A bottom wall of the recess is provided with a protruding portion extending toward the electrode assembly, and the protruding portion is configured to be attached to the air-permeable member, so as to limit deformation of the air-permeable member in a thickness direction of the wall portion. In the technical solution in this embodiment of this application, a wall portion of a housing includes a body portion and a fastener. The fastener is provided with a recess communicating with the outside, where the recess is arranged on an inner surface of the fastener facing an electrode assembly and recessed in a direction leaving the electrode assembly. An air-permeable member covers the recess and allows gas to be discharged to the outside of the housing when a gas pressure inside the housing reaches a threshold, meeting the gas discharge requirement. The bottom wall of the recess is provided with a protruding portion extending toward the electrode assembly, and the protruding portion is attached to the air-permeable member, which can support a side of the air-permeable member facing away from the electrode assembly in the thickness direction, so as to limit deformation of the air-permeable member in the thickness direction of the wall portion under an action of gas inside the housing, thereby slowing down aging of the air-permeable member. An accommodating cavity communicating with the outside is formed between an outer peripheral wall of the protruding portion and an inner peripheral wall of the recess, the bottom wall of the recess is provided with a first through hole, and the first through hole is configured to allow gas circulation with the inner space of the battery cell through the accommodating cavity. The accommodating cavity communicating with the outside is formed between the outer peripheral wall of the protruding portion and the inner peripheral wall of the recess, and the bottom wall of the recess is provided with the first through hole, which can not only ensure that a requirement for discharging the gas inside the battery cell through the accommodating cavity and the first through hole is met, but also facilitate arrangement of the protruding portion so that the protruding portion can be attached to the air-permeable member so as to limit the deformation of the air-permeable member in the thickness direction. In some embodiments, the first through hole is provided in plurality, and the plurality of first through holes are spaced apart. The first through hole is provided in plurality so that a gas discharge rate can be guaranteed and safety performance of the battery cell can be improved. In some embodiments, the protruding portion includes a first protrusion, and the accommodating cavity communicating with the outside is formed between an outer pe