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CN-122025941-A - Insulating film and battery cell

CN122025941ACN 122025941 ACN122025941 ACN 122025941ACN-122025941-A

Abstract

The invention relates to the technical field of batteries, and provides an insulating film and a battery core, wherein the insulating film is used for wrapping the outer side of a pole group of the battery core and comprises a first film group, a second film and a third film, wherein the first film group, the second film and the third film are sequentially connected along a first direction, the second film is provided with a stepped bulge part and a through hole which are arranged at intervals in a second direction, the first direction is perpendicular to the second direction, two ends of the first film group in the second 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 group, the second turnup body is connected with the second film, the third turnup body is connected with the third film, the first film and the third film can be respectively connected with the second film, and the first turnup body, the second turnup body and the third turnup body of each second film group can be connected with the first turnup body and the third film group in parallel to the first turnup body, so that the first turnup body and the second turnup body can form a box 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 film group comprises a first film body, a second film body and a third film body which are sequentially connected along a first direction, wherein the second film body is provided with stepped bulge parts and through holes which are arranged at intervals in a second direction, the stepped bulge parts are suitable for coating stepped convex parts on the end surfaces of the pole groups, and the through holes are suitable for allowing the pole lugs of the pole groups 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, the fourth wrapping portion can be turned over relative to the third wrapping portion, the second wrapping portion and the fourth wrapping portion are at least partially overlapped, and the overlapped portion is opposite to the second film body.
  3. 3. The insulating film of claim 2, wherein the second wrapping portion comprises a fourth fold and a fifth fold connected in the first direction, the fourth fold being connected to the first wrapping portion, the fifth fold being foldable relative to the fourth fold such that the fifth fold is connected to the third wrapping portion and opposite the first wrapping portion.
  4. 4. An insulating film as claimed in claim 3, wherein the inner side of the fifth fold is provided with a glue layer, the fifth fold being capable of being bonded to the third wrapper by the glue layer; And/or the extension length of the fifth turnover body relative to the fourth turnover body in the first direction is h, wherein h is more than or equal to 10mm and less than or equal to 20mm.
  5. 5. The insulating film according to claim 1, wherein the stepped bulge portion includes a first bulge portion and a second bulge portion that are connected in this order in the second direction, the bulge height of the first bulge portion being larger than the bulge height of the second bulge portion; 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, the bulge height of the second bulge part is H2, 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, H1/T1 is less than or equal to 20, H2/T1 is less than or equal to 8, and/or the top wall of the first bulge part is provided with a liquid inlet for electrolyte to pass through.
  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, wherein the cover plate body is arranged on 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, and a stepped sinking groove is formed at the position, corresponding to the boss, of one side of the battery cell cover plate 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 stepped convex part, the pole lugs of the pole group are connected with the first end face, and the stepped convex part is accommodated in the stepped sink; 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 groups are folded relative to the first film group and are wrapped on the two second side faces in a one-to-one correspondence manner, the step-shaped bulge is wrapped on the step-shaped bulge, and the tab is arranged through the via hole.
  7. 7. The battery cell according to claim 6, wherein the battery cell cover plate further comprises a pole, the boss comprises a first supporting table, a mounting table and a second supporting table which are arranged along the length direction of the cover plate body, the mounting table is connected between the first supporting table and the second supporting table, the pole penetrates through the cover plate body and protrudes out of the mounting table, the pole is connected with the pole lug, a first sink groove, a third sink groove and a second sink groove are formed at positions, corresponding to the first supporting table, the mounting table and the second supporting table, of one side of the battery cell cover plate facing the accommodating cavity, the first sink groove and the third sink groove are connected to form the stepped sink groove, and the second sink groove is connected with the third sink groove; the stepped convex part comprises a first convex part and a second convex part which are connected in the length direction, the first convex part is contained in the first sinking groove, the second convex part is contained in the third sinking groove, and the lug is contained in the second sinking groove.
  8. 8. The cell of claim 7, wherein the number of the pole groups is two, each pole group corresponds to one insulating film, the pole group is provided with the pole lugs, the step-shaped convex part is flush with one first side surface and has a space with the other first side surface, one first side surface of the two pole groups is attached to each other, so that two step-shaped convex parts opposite to each other in the width direction of the cover plate body are attached to form a step-shaped convex part, and the step-shaped convex part is accommodated in the step-shaped sink and is in limit fit with the first sink.
  9. 9. The cell of claim 7, wherein the number of the mounting tables and the number of the second support tables are two, the first support table is located between the two second support tables, the two mounting tables are respectively arranged on two sides of the first support table, and each mounting table is provided with the pole in a penetrating manner.
  10. 10. The battery cell of claim 7, wherein the battery cell cover plate further comprises an insulating member, the insulating member is disposed on a side of the cover plate body close to the pole group, the pole is penetrated through the insulating member, and grooves are formed on the side of the cover plate body close to the pole group, corresponding to the positions of the first support table, the mounting table and the second support table; The insulating piece with unsmooth cooperation of recess, the insulating piece keep away from the apron body one side corresponds first brace table the mount table with the position of second brace table corresponds respectively and forms first heavy groove, second heavy groove and third heavy groove.

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 is used for wrapping the outer side of a pole group of an electric core, and comprises the following components: The first film group comprises a first film body, a second film body and a third film body which are sequentially connected along a first direction, wherein the second film body is provided with stepped bulge parts and through holes which are arranged at intervals in a second direction, the stepped bulge parts are suitable for coating stepped convex parts on the end surfaces of the pole groups, and the through holes are suitable for allowing the pole lugs of the pole groups 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. 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, the fourth wrapping portion can be turned over relative to the third wrapping portion, the second wrapping portion and the fourth wrapping portion are at least partially overlapped, and the overlapped portion is opposite to the second film body. According to the insulating film provided by the invention, the second wrapping part comprises the fourth turnover body and the fifth turnover body which are connected in the first direction, the fourth turnover body is connected with the first wrapping part, and the fifth turnover body can be turned relative to the fourth turnover body, so that the fifth turnover body is connected with the third wrapping part and is opposite to the first wrapping part. According to the insulating film provided by the invention, the inner side surface of the fifth turnover body is provided with the adhesive layer, and the fifth turnover body can be adhered to the third wrapping part through the adhesive layer; And/or the extension length of the fifth turnover body relative to the fourth turnover body in the first direction is h, wherein h is more than or equal to 10mm and less than or equal to 20mm. According to the insulating film provided by the invention, the stepped bulge part comprises a first bulge part and a second bulge part