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CN-122026028-A - Battery cell and electricity utilization device

CN122026028ACN 122026028 ACN122026028 ACN 122026028ACN-122026028-A

Abstract

The invention relates to a battery cell and an electric device. In the battery cell, the electrode assembly has a first end face and a second end face opposite in a first direction. The electrode assembly comprises a tab arranged on the first end face. The first direction is an axial direction of the electrode assembly. An insulating adhesive layer surrounds the electrode assembly, and the insulating adhesive layer includes a first portion and a second portion connected to each other. The first part is at least partially adhered to the first end face and covers the edge of the tab. The second portion is at least partially bonded to the peripheral side wall of the electrode assembly. The second portion has an opening communicating with a lower edge of the second portion adjacent the second end face and spaced relative to an upper edge of the second portion connected to the first portion. The design reserves space for the expansion of the electrode assembly, reduces the binding effect on the electrode assembly, and ensures that each region of the electrode assembly can be uniformly expanded and stressed uniformly, thereby reducing the potential short-circuit safety risk caused by the breakage of the pole piece due to stress unbalance.

Inventors

  • LIN HAI
  • TIAN WEN
  • ZHOU FEI
  • YU HONGJIANG
  • WANG RUI

Assignees

  • 江苏正力新能电池技术股份有限公司

Dates

Publication Date
20260512
Application Date
20260116

Claims (10)

  1. 1. A battery cell, comprising: an electrode assembly (100) having a first end face and a second end face that are opposite in a first direction, the electrode assembly (100) including a tab (110) provided at the first end face, the first direction being an axial direction of the electrode assembly (100); The electrode assembly comprises an electrode assembly (100), an insulating adhesive layer (200) surrounding the electrode assembly (100), wherein the insulating adhesive layer (200) comprises a first part (210) and a second part (220) which are connected with each other, the first part (210) is at least partially adhered to the first end face and covers the edge of the tab (110), the second part (220) is at least partially adhered to the peripheral side wall of the electrode assembly (100), the second part (220) is provided with an opening (230), the opening (230) is communicated with the lower edge (222) of the second part (220) close to the second end face, and the opening is arranged at intervals relative to the upper edge (221) of the second part (220) which is connected with the first part (210).
  2. 2. The battery cell of claim 1, wherein a height H1 of the second portion (220) is a distance between the lower edge (222) and the upper edge (221) along the first direction, and a spacing L1 of the openings (230) is a distance between an end of the openings (230) near the upper edge (221) and the upper edge (221) along the first direction, wherein: L1= (50% -95%) H1, preferably l1= (70% -90%) H1; And/or h1=10 to 20mm; and/or the extension length L2 of the opening (230) along the first direction is 5-18 mm.
  3. 3. The battery cell according to claim 1, wherein the number N of the openings (230) is plural, the plural openings (230) are arranged at uniform or non-uniform intervals along the circumferential direction of the electrode assembly (100), and the number N of the openings (230) is 2≤8.
  4. 4. The battery cell of claim 3, wherein the electrode assembly (100) comprises a negative electrode sheet comprising a negative electrode active material; If the mass fraction a of the silicon-based material in the anode active material is more than or equal to 10 percent and less than or equal to 20 percent, and N is more than or equal to 2 and less than or equal to 4; If the mass fraction a of the silicon-based material in the anode active material is less than or equal to 30 percent, N is more than or equal to 5 and less than or equal to 8.
  5. 5. The battery cell according to claim 1, wherein the spacing L3 between any two adjacent openings (230) in the direction of extension of the lower edge (222) is 5-20 mm, and/or, The distance L3 between any two adjacent openings (230) in the extending direction of the lower edge (222) is (1/2-1/8) of the perimeter L4 of the radial section of the electrode assembly (100).
  6. 6. The battery cell according to claim 1, wherein the opening (230) comprises a cutout and/or a notch, wherein the insulating adhesive layer (200) is formed by the fact that the insulating adhesive layer (200) is missing part of the insulating adhesive layer (200) and the insulating adhesive layer (200) can be spliced into a complete insulating adhesive layer (200) at both side parts of the cutout.
  7. 7. The battery cell of claim 6, wherein the opening (230) is a notch and the second portion (220) includes a plurality of sequentially connected rims (231) around the opening (230), any of the rims being straight or curved.
  8. 8. The battery cell of claim 7, wherein at least a portion of the two adjacent edges (231) are rounded.
  9. 9. The battery cell of claim 7, wherein in the first direction, the opening (230) width W1 is the same throughout the opening (230); and/or the width W1=0.5-6 mm, preferably W1=2-5 mm, or W1=pi d/N (5% -15%), d is the diameter of the electrode assembly (100), N is the number of openings, preferably W1=pi d/N (5% -10%); And/or, in the direction that the first end face points to the second end face, the width of the opening (230) at each part of the opening (230) is gradually increased, the width W2=0.5-6 mm, preferably W2=2-5 mm, of the maximum opening (230), or W2=pi d/N (5% -15%), d is the diameter of the electrode assembly (100), N is the number of openings, and preferably W2=pi d/N (5% -10%).
  10. 10. An electrical device, comprising the battery cell according to claims 1-9.

Description

Battery cell and electricity utilization device Technical Field The invention relates to the technical field of new energy, in particular to a battery monomer and an electric device. Background In the current era background of the vigorous development of new energy industry in China, battery cells with high specific energy and high safety are increasingly and widely focused by people, and novel technology layers in the aspects of solid-state batteries, lithium metal batteries and the like are endless. Among them, cylindrical steel-shell battery cells having an energy density of 300Wh/kg or more and battery cell group non-thermal diffusion characteristics have become one of important development directions. Currently commercially applied high-energy density cylindrical battery cells commonly adopt a negative electrode system formed by compounding a silicon-based material with graphite. However, the silicon-based material has a remarkable volume expansion effect in the charge-discharge cycle process, and although the steel shell structure with higher mechanical strength can inhibit the expansion of the battery cell to a certain extent and improve the safety of the battery cell, the restraint effectively ensures that the battery cell is always in a state of incomplete expansion, and the expansion degree is directly limited by the effective inner diameter in the steel shell. Generally, for cylindrical battery cells with tabs at two sides, the housing is negatively charged, and in order to avoid contact short between the edge of the positive tab and the housing, an insulating adhesive layer with low cost and simple process is generally used in industry to cover the edge of the positive tab. However, the battery cell with such a structure has a short-circuit safety risk. Disclosure of Invention Based on this, it is necessary to provide a battery cell and an electric device capable of reducing the risk of short circuit of the battery cell, in view of the problem that the battery cell has the risk of short circuit. In one aspect, the present application provides a battery cell comprising: An electrode assembly has a first end face and a second end face opposite in a first direction. The electrode assembly comprises a tab arranged on the first end face. The first direction is an axial direction of the electrode assembly. And an insulating adhesive layer surrounding the electrode assembly, the insulating adhesive layer including a first portion and a second portion connected to each other. The first part is at least partially adhered to the first end face and covers the edge of the tab. The second portion is at least partially bonded to the peripheral side wall of the electrode assembly. The second part is provided with an opening, and the opening is communicated with the lower edge of the second part, which is close to the second end face, and is arranged at intervals relative to the upper edge of the second part, which is connected with the first part. According to an embodiment of the present application, the height H1 of the second portion is a distance between the lower edge and the upper edge in the first direction, and the interval L1 of the openings is a distance between one end of the opening near the upper edge and the upper edge in the first direction, wherein: l1= (50% -95%) H1, preferably l1= (70% -90%) H1. And/or h1=10 to 20mm. And/or the extension length L2 of the opening along the first direction is 5-18 mm. According to an embodiment of the present application, the number N of the openings is plural, and the plural openings are arranged at uniform or non-uniform intervals along the circumferential direction of the electrode assembly, and 2≤the number N of the openings is equal to or less than 8. According to an embodiment of the present application, the electrode assembly includes a negative electrode sheet including a negative electrode active material. If the mass fraction a of the silicon-based material in the anode active material is more than or equal to 10 percent and less than or equal to 20 percent. N is more than or equal to 2 and less than or equal to 4. If the mass fraction a of the silicon-based material in the anode active material is less than or equal to 30 percent. N is more than or equal to 5 and less than or equal to 8. According to the embodiment of the application, the distance L3 between any two adjacent openings in the extending direction of the lower edge is 5-20 mm. And/or the number of the groups of groups, The distance L3 between any two adjacent openings in the extending direction of the lower edge is (1/2-1/8) of the perimeter L4 of the radial section of the electrode assembly. According to the embodiment of the application, the opening comprises a notch and/or a notch, wherein the insulating adhesive layer is positioned at two sides of the notch and can be spliced into a complete insulating adhesive layer, and the notch is formed by the insulating adhesive layer with the