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CN-122029668-A - Housing, battery cell, battery and electricity utilization device

CN122029668ACN 122029668 ACN122029668 ACN 122029668ACN-122029668-A

Abstract

The embodiment of the application provides a shell, a battery cell, a battery and an electric device. The shell is provided with an opening and is of an integrated structure, the shell comprises a first wall and at least two second walls, the first wall and the second walls are oppositely arranged with the opening, the first wall and the second walls are intersected, two second walls in the at least two second walls are connected through a first round corner, the inner diameter of the first round corner is R1, the yield strength of the shell under the condition that the temperature is 25 ℃ is Re, wherein Re and R1 meet the conditions that Re is more than or equal to 140MPa and less than or equal to 1000MPa, R1 is more than or equal to 2.5mm and less than or equal to 20mm. The shell, the battery monomer, the battery and the power utilization device can reduce the problem that the shell is wrinkled and cracked due to stacking at the round corners in the process of integrally forming the shell.

Inventors

  • CHEN XINXIANG
  • HUANG SHOUJUN
  • ZHENG YULIAN
  • LIN DENGHUA
  • WANG PENG
  • JIN HAIZU

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260512
Application Date
20231117

Claims (20)

  1. A shell, which is characterized in that the shell is provided with an opening and is of an integrated structure, the shell comprises a first wall and at least two second walls, wherein the first wall and the second walls are arranged opposite to the opening, and the first wall and the second walls are arranged in an intersecting way; Two second walls of the at least two second walls are connected through a first round corner, the inner diameter of the first round corner is R1, the yield strength of the shell body at the temperature of 25 ℃ is Re, wherein Re and R1 are 140 MPa-1000 MPa, and 2.5 mm-20 mm-2 mm-1.
  2. The housing of claim 1, wherein Re and R1 satisfy 150 MPa≤Re≤400 MPa,4 mm≤R1≤15 mm.
  3. The housing according to claim 1 or2, wherein the depth of the housing is H, H satisfying 50mm < h≤250 mm.
  4. A casing according to any one of claims 1 to 3 wherein the casing has a tensile strength Rm at 25 ℃ satisfying 250MPa +.rm +.2000 MPa.
  5. The housing of any one of claims 1 to 4, wherein the two second walls are two adjacent second walls, and wherein a maximum thickness T1 of the first rounded corner is satisfied between a maximum thickness T0 of a second wall having a maximum thickness of the two second walls, T1> T0.
  6. The housing of any one of claims 1 to 4, wherein the two second walls are two second walls disposed opposite each other.
  7. The housing of any one of claims 1 to 6, wherein the first wall and the second wall are connected by a second fillet, and wherein an inner diameter r1 of the second fillet is 2.0≤r1/T2≤30 with a minimum thickness T2 of a second wall of the at least two second walls having a minimum thickness.
  8. The housing according to any one of claims 1 to 7, wherein the wall thickness of the housing is uniform.
  9. The housing of any one of claims 1 to 8, wherein the material of at least a partial region of the housing comprises at least one of stainless steel and carbon steel.
  10. The housing according to any one of claims 1 to 9, wherein the mass content of chromium element in the material of at least part of the region of the housing is m, m satisfying 10% +≤30%.
  11. The housing according to claim 9 or 10, wherein at least a partial region of the housing comprises all walls of the housing.
  12. A battery cell comprising an electrode assembly and the case according to any one of claims 1 to 11, the electrode assembly being accommodated in the case.
  13. The cell of claim 12, wherein the cell has a thickness D1, wherein H, R mm +.r1 x D1/H +.36 mm is satisfied between H, R and D1.
  14. The battery cell of claim 13, wherein H, R1 and D1 meet 0.34 mm≤R1≤D1/H≤18 mm.
  15. The battery cell of any one of claims 12 to 14, wherein the electrode assembly has a thickness D2, and wherein 0.125R 1/D2 is 0.45 or less between R1 and D2.
  16. The battery cell according to any one of claim 12 to 15, wherein, The electrode assembly comprises a negative electrode plate, wherein the negative electrode plate comprises a negative electrode active material capable of reversibly releasing and embedding metal ions, and the negative electrode active material comprises a silicon-based material; At least part of the shell has tensile strength Rm at 25 ℃, wherein Rm is more than or equal to 250MPa and less than or equal to 2000MPa.
  17. The battery cell according to any one of claims 12 to 16, wherein, The electrode assembly comprises a negative electrode plate, wherein the negative electrode plate comprises a negative electrode active material capable of reversibly releasing and embedding metal ions, and the negative electrode active material comprises a silicon-based material; At least part of the shell has the yield strength Re at the temperature of 25 ℃ which is 140 MPa-1000 MPa.
  18. The battery cell according to any one of claim 12 to 17, wherein, The electrode assembly comprises a positive electrode sheet comprising a positive electrode active material capable of reversibly releasing-intercalating metal ions, the positive electrode active material comprising a nickel-containing elemental compound; At least part of the area of the shell has a melting point p, and p is not less than 1200 ℃ and not more than 2000 ℃.
  19. The battery cell of any one of claims 12 to 18, wherein the electrode assembly comprises a positive electrode sheet comprising a positive electrode active material capable of reversibly de-intercalating metal ions, the positive electrode active material comprising a nickel-containing elemental compound; at least part of the shell has tensile strength Rn at 500 ℃, and Rn is 100MPa or less and 1200MPa or less.
  20. A battery, comprising: a plurality of battery cells, the battery cells being as defined in any one of claims 12 to 19.

Description

Housing, battery cell, battery and electricity utilization device Technical Field The application relates to the technical field of batteries, in particular to a shell, a battery cell, a battery and an electric device. Background In general, the housing of the battery cell has a great influence on the performance of the battery cell itself. Therefore, how to improve the performance of the battery cell by improving the case is a problem that has been studied. Disclosure of Invention In view of the above, the embodiment of the application provides a housing, a battery cell, a battery and an electric device, which can reduce the problem of wrinkling and cracking of the housing caused by stacking at a fillet in the process of integrally forming the housing. According to the first aspect, the shell is provided with an opening, the shell is of an integrated structure and comprises a first wall and at least two second walls, the first wall and the second walls are arranged opposite to the opening, the first wall and the second walls are intersected, two second walls of the at least two second walls are connected through a first round angle, the inner diameter of the first round angle is R1, the yield strength of the shell under the condition that the temperature is 25 ℃ is Re, wherein Re and R1 meet the conditions that Re is 140 MPa-1000 MPa, R1 is 2.5 mm-20 mm. In the embodiment, the shell is made of a material with the yield strength Re being 140 MPa-1000 MPa, the wall thickness of the shell can be thinned under the condition that the strength of the shell is not reduced, so that the capacity space of a battery cell can be improved, and in addition, the problem of shell cracking caused by the stress of a high-strength material in the integral forming process is solved as far as possible by setting the inner diameter R1 of a first round corner between two second walls to be 2.5 mm-20 mm, and the forming difficulty of the shell is reduced. In one possible implementation, re and R1 satisfy 150 MPa≤Re≤400 MPa,4 mm≤R1≤15 mm. In this example, by defining Re 150MPa 400MPa 4mm R1 15mm helps to balance the difficulty of forming the shell with the degree of deformation. In one possible implementation, the depth of the shell is H, which satisfies 50mm < H≤250 mm. In the embodiment, the depth H of the shell meets 50mm < H less than or equal to 250mm, so that the problem of shell cracking caused by stress of the high-strength material in the integral forming process can be reduced as much as possible under the condition that the energy density of the battery monomer is not influenced, and the forming difficulty of the shell is further reduced. In one possible implementation, the tensile strength of the shell at 25 ℃ is Rm, which satisfies that 250 MPa≤Rm≤2000 MPa. In the embodiment, by setting 250 MPa-2000 MPa and 2.5 mm-20 mm R1, the stress of the die can be reduced as much as possible in the manufacturing process of the shell without affecting the strength of the shell, and the size or surface of the shell can be unaffected. In one possible implementation, the two second walls are two adjacent second walls, and the maximum thickness T1 of the first rounded corner and the maximum thickness T0 of the second wall with the greatest thickness of the two second walls satisfy T1> T0. In this embodiment, by providing the first rounded corner between the two adjacent second walls and setting the maximum thickness T1 of the first rounded corner to be greater than the maximum thickness T0 of the second wall having the greatest thickness among the two second walls, it is advantageous to solve the problem that the case is deformed during the production and assembly of the battery cell and the problem that the case is deformed due to the expansion of the generated gas during the use of the battery cell. In one possible implementation, the two second walls are two second walls arranged opposite each other. In this embodiment, by providing the first fillet between two oppositely disposed second walls, the risk of cracking of the housing caused by the stress of the high strength material during the integral molding process is further facilitated by increasing the inner diameter R1 of the first fillet. In one possible implementation, the first wall and the second wall are connected by a second fillet, and the inner diameter r1 of the second fillet and the minimum thickness T2 of the second wall with the minimum thickness of at least two second walls satisfy that r1/T2 is more than or equal to 2.0 and less than or equal to 30. In this embodiment, the ratio of the inner diameter r1 of the second rounded corner between the first wall and the second wall to the minimum thickness T2 of the second wall with the smallest wall thickness is set between [2.0,30] to help balance the difficulty of processing the case with the space capacity and strength of the battery cell. In one possible implementation, the wall thickness of the housing is uniform. I