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CN-224217510-U - Insulating film of battery cell assembly and battery cell

CN224217510UCN 224217510 UCN224217510 UCN 224217510UCN-224217510-U

Abstract

The utility model provides an insulating film of a battery cell assembly and the battery cell, wherein the battery cell assembly is a winding type battery cell assembly, the insulating film comprises a bottom surface coverage area, a first side surface coverage area, a second side surface coverage area, a third side surface coverage area, a fourth side surface coverage area, a first overlapping coverage area and a second overlapping coverage area, the width of the first overlapping coverage area and the width of the second overlapping coverage area are smaller than the width of a corner part along the width direction of the battery cell assembly, and when the insulating film is in a folding state, the first overlapping coverage area and the second overlapping coverage area are overlapped with the first overlapping part and the second overlapping part of the first side surface coverage area or the second side surface coverage area respectively. The corner part is formed with a gap between the thickness direction of the battery cell assembly and the coverage area of the first side surface and the coverage area of the second side surface, and the gap accommodates the overlapping part of the insulating film and can not cause interference between the insulating film and the battery cell assembly, so that the overlapping part of the insulating film can not increase the occupied space of the insulating film in the thickness direction of the battery cell assembly, and the energy density of the battery cell is improved.

Inventors

  • Jia Lianghao

Assignees

  • 远景动力技术(湖北)有限公司
  • 远景动力技术(江苏)有限公司
  • 远景睿泰动力技术(上海)有限公司

Dates

Publication Date
20260508
Application Date
20250526

Claims (10)

  1. 1. The insulating film of the battery cell assembly is a winding type battery cell assembly, the battery cell assembly comprises a main body part and corner parts arranged at two ends of the main body part along the width direction of the battery cell assembly, the battery cell assembly is provided with a bottom surface, a first side surface and a second side surface which are arranged at intervals along the thickness direction of the battery cell assembly, and a third side surface and a fourth side surface which are arranged at intervals along the width direction of the battery cell assembly, and the insulating film of the battery cell assembly is characterized by comprising a bottom surface coverage area, a first side surface coverage area, a second side surface coverage area, a third side surface coverage area, a fourth side surface coverage area, a first overlapping coverage area and a second overlapping coverage area; the bottom surface coverage area is used for covering the bottom surface; The bottom surface coverage area extends along a first direction to form the first side surface coverage area, and the first side surface coverage area is used for covering the first side surface; the bottom surface coverage area extends along a second direction to form a second side surface coverage area, and the second side surface coverage area is used for covering the second side surface; One of the first side coverage area and the second side coverage area extends along a third direction to form a third side coverage area, the third side coverage area is used for covering the third side, one end of the other of the first side coverage area and the second side coverage area, which faces the third direction, is provided with a first overlapping part, one of the first side coverage area and the second side coverage area extends along a fourth direction to form a fourth side coverage area, the fourth side coverage area is used for covering the fourth side, one end of the other of the first side coverage area and the second side coverage area, which faces the fourth direction, is provided with a second overlapping part, and the third direction and the fourth direction are two opposite directions in the width direction of the battery module; The third side surface coverage area extends along the third direction to form the first overlapped coverage area, and the width of the first overlapped coverage area in the width direction of the battery cell component is smaller than the width of the corner part of the corresponding side in the width direction of the battery cell component; The fourth side surface coverage area extends along the fourth direction to form the second overlapping coverage area, the width of the second overlapping coverage area in the width direction of the battery cell assembly is smaller than the width of the corner part of the corresponding side in the width direction of the battery cell assembly, and when the insulating film of the battery cell assembly is in a folded state, the second overlapping coverage area overlaps with the second overlapping part.
  2. 2. The insulating film of a cell assembly of claim 1, wherein a width of the first overlap footprint in a width direction of the cell assembly is equal to a width of the second overlap footprint in a width direction of the cell assembly.
  3. 3. The insulating film of a cell assembly of claim 2, wherein a width of the first overlap footprint in a width direction of the cell assembly is defined as M, M < H/(2 x n x l); Wherein H is the thickness of the battery cell assembly, n is the number of winding cores in the battery cell assembly, and L is the width of the battery cell assembly.
  4. 4. The insulating film of a cell assembly according to claim 1, wherein when the insulating film of the cell assembly is in a folded state, the first overlapping region is provided on a side of the first overlapping portion away from the bottom surface covering region in a thickness direction of the cell assembly, the second overlapping region is provided on a side of the second overlapping portion away from the bottom surface covering region in the thickness direction of the cell assembly, the first overlapping region covers the first overlapping region, and the second overlapping region covers the second overlapping region.
  5. 5. The insulating film of a cell assembly according to claim 1, wherein when the insulating film of the cell assembly is in a folded state, the first overlapping region is provided on a side of the first overlapping portion adjacent to the bottom surface covering region in a thickness direction of the cell assembly, the second overlapping region is provided on a side of the second overlapping portion adjacent to the bottom surface covering region in a thickness direction of the cell assembly, the first overlapping region covers the first overlapping region, and the second overlapping region covers the second overlapping region.
  6. 6. The insulating film of a cell assembly according to claim 5, wherein a width of one end of the bottom surface covering region in the third direction in the thickness direction of the cell assembly is defined as a 1 , a width of one end of the bottom surface covering region in the fourth direction in the thickness direction of the cell assembly is defined as a 2 , a width of the third side surface covering region in the width direction of the cell assembly is defined as b, a width of the fourth side surface covering region in the width direction of the cell assembly is defined as c, and a thickness of the insulating film of the cell assembly is defined as t; Wherein b=a 1 -t,c=a 2 -t.
  7. 7. The insulating film of a cell assembly of claim 4 or 5, further comprising a cover connection for connection with a cover of a cell; The cover plate connecting portion is located in one of the first overlapping coverage area and the first overlapping portion, which is away from the bottom surface coverage area in the thickness direction of the cell assembly, and/or the cover plate connecting portion is located in one of the second overlapping coverage area and the second overlapping portion, which is away from the bottom surface coverage area in the thickness direction of the cell assembly.
  8. 8. The insulating film of a cell assembly of claim 1, wherein the first side coverage area extends in the third direction to form the third side coverage area, the first side coverage area extends in the fourth direction to form the fourth side coverage area, an end of the second side coverage area toward the third direction is formed with the first overlap portion, and an end of the second side coverage area toward the fourth direction is formed with the second overlap portion.
  9. 9. The insulating film of a cell assembly of claim 1, wherein the first side coverage area extends in the third direction to form the third side coverage area, the second side coverage area extends in the fourth direction to form the fourth side coverage area, an end of the second side coverage area toward the third direction is formed with the first overlap, and an end of the first side coverage area toward the fourth direction is formed with the second overlap.
  10. 10. A battery cell, which is characterized by comprising a shell, a battery cell assembly and an insulating film of the battery cell assembly as claimed in any one of claims 1-9, wherein the insulating film of the battery cell assembly is coated on the outer surface of the battery cell assembly, and the insulating films of the battery cell assembly and the battery cell assembly are both arranged in the shell.

Description

Insulating film of battery cell assembly and battery cell Technical Field The utility model relates to the field of batteries, in particular to an insulating film of a battery cell assembly and a battery cell. Background The square battery is a commonly used lithium ion power battery structure at present, and is formed by assembling a winding type battery cell assembly or a lamination type battery cell assembly which is prepared from a positive electrode, a negative electrode and a diaphragm into a square shell for packaging. When the shell assembly process is carried out, because the shell is generally an aluminum shell or a steel shell which is harder in material, the edge of the shell is sharp and burrs exist, and the risk of damage to the battery cell assembly caused by scratching the battery cell assembly and the like exists in the shell assembly process. Therefore, before the battery cell assembly is assembled into the shell, the battery cell assembly needs to be coated with an insulating film (also called a Mylar film) which is soft and has good flexibility so as to isolate the direct contact between the battery cell assembly and an external aluminum shell, and adverse effects such as short circuit of the battery cell assembly, corrosion of the aluminum shell, scratch damage of the battery cell assembly by the aluminum shell and the like are avoided. The prior insulating film assembly process comprises the steps of firstly carrying out hot melting on the bottom coating surface of the insulating film and the bottom supporting plate, then bending the large-surface coating surface on the long side of the bottom of the battery cell assembly to cover the side surface with larger area of the battery cell assembly, then wrapping the side surface with smaller area of the battery cell assembly by the bending side coating surface, and finally carrying out plastic hot melting on each point on the top of the insulating film and the lower part of the cover plate of the battery cell to realize omnibearing wrapping of the battery cell assembly. At present, the insulating film structure is overlapped and fixed on the side face of the battery cell assembly after being folded, but the overlapped part of the insulating film can enable the insulating film to occupy more space, so that the insulating film can occupy the space of the battery cell assembly under the condition that the internal space of the battery cell shell is unchanged, and the energy density of the battery cell is reduced. Disclosure of utility model The utility model aims to overcome the defect that the insulating film occupies too much space of a battery cell assembly to reduce the energy density of the battery cell because the insulating film is overlapped and fixed on the side surface of the battery cell assembly after being folded in the prior art. The utility model solves the technical problems by the following technical scheme: The insulation film of the battery cell assembly is a winding type battery cell assembly, the battery cell assembly comprises a main body part and corner parts arranged at two ends of the main body part along the width direction of the battery cell assembly, the battery cell assembly is provided with a bottom surface, a first side surface, a second side surface, a third side surface and a fourth side surface, wherein the first side surface and the second side surface are arranged at intervals along the thickness direction of the battery cell assembly, the third side surface and the fourth side surface are arranged at intervals along the width direction of the battery cell assembly, and the insulation film of the battery cell assembly comprises a bottom surface coverage area, a first side surface coverage area, a second side surface coverage area, a third side surface coverage area, a fourth side surface coverage area, a first overlapping coverage area and a second overlapping coverage area; the bottom surface coverage area is used for covering the bottom surface; The bottom surface coverage area extends along a first direction to form the first side surface coverage area, and the first side surface coverage area is used for covering the first side surface; the bottom surface coverage area extends along a second direction to form a second side surface coverage area, and the second side surface coverage area is used for covering the second side surface; One of the first side coverage area and the second side coverage area extends along a third direction to form a third side coverage area, the third side coverage area is used for covering the third side, one end of the other of the first side coverage area and the second side coverage area, which faces the third direction, is provided with a first overlapping part, one of the first side coverage area and the second side coverage area extends along a fourth direction to form a fourth side coverage area, the fourth side coverage area is used for covering the fourth side, one en