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CN-122025942-A - Insulating film and battery cell

CN122025942ACN 122025942 ACN122025942 ACN 122025942ACN-122025942-A

Abstract

The invention relates to the technical field of batteries, and provides an insulating film and a battery cell. The insulation film is used for wrapping the outer side of the pole group of the battery core and comprises a first film group, a second film body and a third film body, wherein the first film body, the second film body and the third film body are sequentially connected along a first direction, the second film body is provided with a first bulge part and a second bulge part which are arranged at intervals in a second direction, the second bulge part is provided with a through hole for a pole lug to pass through, two ends of the first film group in the second direction perpendicular to the first direction are respectively connected with a second film group, the second film group comprises a first turnup body, a second turnup body and a third turnup body which are distributed along the first direction, the first turnup body is connected with the first film body, the second turnup body is connected with the second film body, the third turnup body is connected with the third film body, the first turnup body and the second film body can be turned up and connected with the third film body at intervals, and the first turnup body and the second turnup body of each second film group can be turned up and connected with the first turnup body and the second turnup body relatively to enable the first turnup body and the two second film groups to form a box body structure.

Inventors

  • XIN XUEQIAN

Assignees

  • 蜂巢能源科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260203

Claims (10)

  1. 1. An insulating film for wrapping outside a pole group of an electric core, comprising: The first membrane group comprises a first membrane body, a second membrane body and a third membrane body which are sequentially connected along a first direction, wherein the second membrane body is provided with a first bulge part and a second bulge part which are arranged at intervals in a second direction, the first bulge part is suitable for coating a convex part on the end face of the pole group, the second bulge part is suitable for partially coating a pole lug of the pole group, and the second bulge part is provided with a through hole for the pole lug to pass through; The two ends of the first film group in the second direction are respectively connected with one second film group, the second film group comprises a first turnover body, a second turnover body and a third turnover body which are distributed along the first direction, the first turnover body is connected with the first film body, the second turnover body is connected with the second film body, and the third turnover body is connected with the third film body; The first membrane body and the third membrane body can be respectively turned over relative to the second membrane body and are connected, each second membrane group is provided with a first turnup body, a second turnup body and a third turnup body, the first turnup body, the second turnup body and the third turnup body can be turned over relative to the first membrane group and are connected, and the first membrane group and the two second membrane groups are enclosed to form a box body structure.
  2. 2. The insulating film of claim 1, wherein the first film body comprises a first wrapping portion and a second wrapping portion connected to each other, the first wrapping portion being connected to the second film body; the third film body comprises a third wrapping part and a fourth wrapping part which are connected, and the third wrapping part is connected with the second film body; The second wrapping portion can be turned over relative to the first wrapping portion, and the fourth wrapping portion can be turned over relative to the third wrapping portion, so that the second wrapping portion and the fourth wrapping portion at least partially overlap and are opposite to the second film body.
  3. 3. The insulating film according to claim 2, wherein the second wrapping portion includes a fourth folding body and a fifth folding body, the fourth folding body is connected to the first wrapping portion, both ends of the fourth folding body in the second direction are provided with the fifth folding body, and in a case that the fourth folding body is folded with respect to the first wrapping portion, the fifth folding body is folded with respect to the fourth folding body, so that the fifth folding body can be overlapped with the first folding body and the third folding body.
  4. 4. An insulating film according to claim 3, wherein an extension length of the fifth turnover body in the second direction with respect to the fourth turnover body is B,10 mm≤b≤20 mm; and/or, the fourth wrapping part is provided with a plurality of exhaust holes, and the fourth turnover body is used for being overlapped and arranged on the outer side of the fourth wrapping part.
  5. 5. The insulating film according to claim 1, wherein a top wall of any one of the first bulge portions is provided with a liquid inlet for passing an electrolyte; And/or the wall thickness of the top wall of the first bulge part and the wall thickness of the top wall of the second bulge part are T1, the wall thickness of other areas are T2, the bulge height of the first bulge part is H1, T1 is more than or equal to 0.25mm and less than or equal to 0.35mm, T2 is more than or equal to 0.08mm and less than or equal to 0.15mm, and H1/T1 is more than or equal to 20.
  6. 6. A kind of electric core, characterized by comprising the following steps: The battery cell shell is provided with an opening; The battery cell cover plate comprises a cover plate body and a pole, wherein the cover plate body is arranged in the opening and surrounds the battery cell shell to form a containing cavity, a boss is arranged on one side of the cover plate body away from the containing cavity, the pole penetrates through the cover plate body and is positioned on the lateral side of the boss in the length direction of the cover plate body, and a groove is formed in the position, corresponding to the boss, of one side of the cover plate body facing the containing cavity; the pole group is arranged in the accommodating cavity, is provided with a first end face and a second end face which are opposite to each other, and two first side faces and two second side faces which are connected between the first end face and the second end face, wherein the two first side faces are opposite to each other, the two second side faces are opposite to each other, the first end face is convexly provided with a convex part, the pole lugs of the pole group are connected with the first end face, and the convex part is at least partially accommodated in the groove; The insulating film according to any one of claims 1 to 5, wherein the second film body is wrapped on the first end face, the first film body and the third film body are respectively wrapped on the two first side faces and the second end face, the two second film bodies are wrapped on the two second side faces in a one-to-one correspondence manner, the first bulge is wrapped on the convex part, the second bulge is wrapped on a part of the tab, and the tab is arranged through the through hole and connected with the pole.
  7. 7. The battery cell according to claim 6, wherein the number of the pole groups is two, each pole group corresponds to one insulating film, the pole groups are provided with the pole lugs, the protruding portions are flush with one of the first side surfaces, a space exists between the protruding portions and the other first side surface in the width direction of the cover plate body, one first side surface of the two pole groups is attached, and two protruding portions opposite to each other in the width direction are combined to form a protruding package, and the protruding package is at least partially accommodated in the groove.
  8. 8. The battery cell according to claim 7, wherein the battery cell cover plate further comprises an insulating member, the insulating member is connected to one side of the cover plate body, which faces the pole group, the insulating member is in concave-convex fit with the groove, a sinking groove is formed at a position, corresponding to the groove, of one side, which is far away from the cover plate body, of the insulating member, and the convex hull is at least partially accommodated in the sinking groove and is in limit fit with the sinking groove.
  9. 9. The cell of claim 6, wherein the tab has a root section and a folded section, the root section is connected to the first end surface, the folded section is connected to an end of the root section away from the first end surface, a position where the root section and the folded section are connected is a folded position of the tab, and the second raised portion is contoured with the root section and is wrapped around the root section.
  10. 10. The cell of claim 9, wherein the second raised portion has a raised height b, the folded position has a height a relative to the first end surface of 0.5mm ∈a ∈1.5mm,0.2mm ∈b-a ∈0.5mm; and/or, in the length direction of the cover plate body, the distance between the tab and the via hole is G1, and G1 is more than or equal to 2mm and less than or equal to 4mm; And/or, in the width direction of the cover plate body, the width of the through hole is A, the thickness of the lug is t, A-t is more than or equal to 2mm and less than or equal to 4mm, and t is more than or equal to 0.2mm and less than or equal to 0.7mm.

Description

Insulating film and battery cell Technical Field The invention relates to the technical field of batteries, in particular to an insulating film and an electric core. Background The battery pack comprises a box body and a battery module assembled in the box body, the battery module is composed of a plurality of electric cores, electric connection is achieved between the poles of the electric cores through a bus bar, and the box body provides physical support and protection for the battery module. The battery cell comprises a battery cell shell, a battery cell cover plate and a pole group, wherein the pole group is arranged in a containing cavity formed by surrounding the battery cell shell and the battery cell cover plate. The battery cell cover plate comprises a cover plate body, a pole column and an insulating piece, wherein the pole column is arranged on the cover plate body, the cover plate body is welded, sealed and fixed with the battery cell shell, and the insulating piece is positioned between the cover plate body and the pole group and defines a space for accommodating the pole lugs of the pole group with the pole group. The outside of the pole group is wrapped with an insulating film so as to realize insulation between the pole group and the battery cell shell. In the conventional cell structure, the insulating film and the insulating member are fixed by heat fusion. However, in some cell structures, the thin insulating member affects the fixed yield of the insulating member and the insulating film, which affects the performance of the cell. Disclosure of Invention The invention provides an insulating film and a battery cell, which are used for solving the problem of low yield of the insulating film fixation in the traditional battery cell. The invention provides an insulating film, which comprises a pole group, a first electrode and a second electrode, wherein the pole group is used for wrapping an electric core, and comprises: The first membrane group comprises a first membrane body, a second membrane body and a third membrane body which are sequentially connected along a first direction, wherein the second membrane body is provided with a first bulge part and a second bulge part which are arranged at intervals in the second direction, the first bulge part is suitable for coating a convex part on the end face of the pole group, the second bulge part is suitable for partially coating a pole lug of the pole group, and the second bulge part is provided with a through hole for the pole lug to pass through; The two ends of the first film group in the second direction are respectively connected with one second film group, the second film group comprises a first turnover body, a second turnover body and a third turnover body which are distributed along the first direction, the first turnover body is connected with the first film body, the second turnover body is connected with the second film body, and the third turnover body is connected with the third film body; The first membrane body and the third membrane body can be respectively turned over relative to the second membrane body and are connected, each second membrane group is provided with a first turnup body, a second turnup body and a third turnup body which can be turned over relative to the first membrane group and are connected, and the first membrane group and the two second membrane groups are combined into a box body structure. According to the insulating film provided by the invention, the first film body comprises a first wrapping part and a second wrapping part which are connected, and the first wrapping part is connected with the second film body; The second wrapping portion can be turned over relative to the first wrapping portion, and the fourth wrapping portion can be turned over relative to the third wrapping portion, so that the second wrapping portion and the fourth wrapping portion at least partially overlap and are opposite to the second film body. According to the insulating film provided by the invention, the second wrapping part comprises the fourth folding body and the fifth folding body, the fourth folding body is connected with the first wrapping part, the fifth folding body is arranged at two ends of the fourth folding body in the second direction, and under the condition that the fourth folding body is folded relative to the first wrapping part, the fifth folding body is folded relative to the fourth folding body, so that the fifth folding body, the first folding body and the third folding body can be overlapped. According to the insulating film provided by the invention, the extension length of the fifth turnover body relative to the third turnover body in the second direction is B, and B is more than or equal to 10mm and less than or equal to 20mm; and/or, the fourth wrapping part is provided with a plurality of exhaust holes, and the fourth turnover body is used for being overlapped and arranged on the outer side of t