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CN-224217651-U - Lithium battery top cover structure

CN224217651UCN 224217651 UCN224217651 UCN 224217651UCN-224217651-U

Abstract

The utility model discloses a top cover structure of a lithium battery, which relates to the technical field of lithium batteries and comprises a top cover, wherein the top cover is provided with an explosion-proof hole, and the top cover is characterized in that the explosion-proof hole is sequentially provided with a protective cover, an explosion-proof film and a deformation layer from top to bottom, the protective cover, the explosion-proof film and the deformation layer are all connected to the top cover, the surface of the protective cover is provided with air holes, the deformation layer is of a downward arch structure, the deformation layer comprises a first metal layer and a second metal layer arranged on the first metal layer, the thermal expansion coefficient of the first metal layer is larger than that of the second metal layer, and a plurality of sharp knives are uniformly distributed on the surface of the second metal layer.

Inventors

  • MA QIPING

Assignees

  • 东莞市惠德科技有限公司

Dates

Publication Date
20260508
Application Date
20250412

Claims (8)

  1. 1. The lithium battery top cover structure comprises a top cover and is characterized in that the top cover is provided with an explosion-proof hole, a protective cover, an explosion-proof film and a deformation layer are sequentially arranged in the explosion-proof hole from top to bottom, the protective cover, the explosion-proof film and the deformation layer are connected to the top cover, air holes are formed in the surface of the protective cover, the deformation layer is of a downward arch structure, the deformation layer comprises a first metal layer and a second metal layer arranged on the first metal layer, the thermal expansion coefficient of the first metal layer is larger than that of the second metal layer, and a plurality of sharp knives are uniformly distributed on the surface of the second metal layer.
  2. 2. The lithium battery top cover structure according to claim 1, wherein the protective cover is welded on the top surface of the top cover, and the protective cover covers the explosion-proof hole.
  3. 3. The lithium battery top cover structure according to claim 1, wherein the protective cover is a cylindrical structure with an opening at the bottom and a narrow top and a wide bottom.
  4. 4. The lithium battery top cover structure according to claim 1, wherein the number of the ventilation holes is several, and the ventilation holes are located at the side face of the protective cover.
  5. 5. The lithium battery top cover structure according to claim 1, wherein the first metal layer is a copper metal sheet and the second metal layer is an iron metal sheet.
  6. 6. The lithium battery top cover structure according to claim 1, wherein the first metal layer and the second metal layer are connected by welding.
  7. 7. The lithium battery top cover structure according to claim 1, wherein the explosion-proof membrane is a sheet-like structure having the same shape as the cross-sectional shape of the explosion-proof hole, and the diameter of the explosion-proof membrane is larger than the diameter of the explosion-proof hole.
  8. 8. The lithium battery top cover structure according to claim 1, wherein the explosion-proof membrane is made of aluminum.

Description

Lithium battery top cover structure Technical Field The utility model relates to the technical field of lithium batteries, in particular to a top cover structure of a lithium battery. Background With the development of electric automobiles, the demand for lithium batteries, which are batteries using a nonaqueous electrolyte solution with lithium metal or lithium alloy as a negative electrode material, is gradually increasing. The lithium battery mainly comprises a shell, an electric core and a top cover, wherein the top cover is generally provided with an explosion-proof valve to ensure the safety performance of the battery, and when the internal air pressure of the battery reaches a critical value, the explosion-proof valve is started to release air to the battery. The explosion-proof structure adopting the explosion-proof valve has certain defects that when the battery heats or heats to a certain degree, the explosion-proof valve can not radiate the heat of the battery, and the explosion-proof valve can be started only when the battery heats to the limit and the air pressure reaches the critical value, so that a certain delay exists for the thermal protection of the battery, and the risks of burning and explosion accidents of the battery are increased. Disclosure of utility model The utility model discloses a top cover structure of a lithium battery, which aims to solve the technical problem of delay in thermal protection of the battery. In order to solve the technical problems, the utility model provides the following optimization technical scheme: A lithium battery top cover structure comprises a top cover, wherein the top cover is provided with an explosion-proof hole, a protective cover, an explosion-proof film and a deformation layer are sequentially arranged in the explosion-proof hole from top to bottom, the protective cover, the explosion-proof film and the deformation layer are connected to the top cover, air holes are formed in the surface of the protective cover, the deformation layer is of a downward arch structure, the deformation layer comprises a first metal layer and a second metal layer arranged on the first metal layer, the thermal expansion coefficient of the first metal layer is larger than that of the second metal layer, and a plurality of sharp knives are uniformly distributed on the surface of the second metal layer. Further, the protection casing welds in the top surface of top cap, the protection casing covers explosion-proof hole. Further, the protective cover is of a cylindrical structure with an opening at the bottom and a narrow upper part and a wide lower part. Further, the number of the air holes is set to be a plurality, and the plurality of the air holes are located on the side face of the protective cover. Further, the first metal layer is a copper metal sheet and the second metal layer is an iron metal sheet. Further, the first metal layer and the second metal layer are connected in a welding mode. Further, the rupture disk is of a sheet-like structure having the same shape as the cross-sectional shape of the rupture disk, and the diameter of the rupture disk is larger than that of the rupture disk. Further, the explosion-proof membrane is made of aluminum. Compared with the prior art, the utility model has the following beneficial effects: According to the lithium battery top cover structure, the plurality of sharp knives are uniformly arranged at intervals of the deformation layer, the deformation layer is of a downward arch structure, namely, the sharp knives on the deformation layer gradually approach the explosion-proof film from the center to the periphery, when the battery generates heat, the deformation amount of the first metal layer is larger than that of the second metal layer, so that the deformation layer is upwards arched, the sharp knives on the periphery of the deformation layer are closer to the explosion-proof film than the sharp knives in the center, the sharp knives on the periphery of the deformation layer penetrate through the explosion-proof film for releasing heat and releasing air of the battery, when the battery continuously generates heat, the sharp knives on the periphery of the deformation layer gradually penetrate through the explosion-proof film from the sharp knives in the center to increase the releasing heat and the releasing air, a safe reaction can be made at the initial stage of the battery, corresponding reaction can be continuously made according to the heating condition of the battery, the accident risk of the battery heat is effectively avoided, the structure is simple, and the safety coefficient is higher. Drawings Fig. 1 is a schematic structural view of the present utility model. Fig. 2 is a cross-sectional view of the structure of the present utility model. In the figure, 1, a top cover, 2, explosion-proof holes, 3, a protective cover, 4, an explosion-proof film, 5, a deformation layer, 6, ventilation holes, 7 and a sharp knif