CN-122000493-A - Winding cell, battery cell and battery device

CN122000493ACN 122000493 ACN122000493 ACN 122000493ACN-122000493-A

Abstract

The invention discloses a winding electric core, a battery cell and a battery device. The negative pole piece includes negative pole piece body, negative pole tab and first protective layer, and the negative pole tab is connected at least one end of negative pole piece body along width direction, and first protective layer covers negative pole tab and negative pole piece body junction, and first protective layer is the conductive ion layer. The positive pole piece comprises a positive pole piece body and a positive pole lug, and the positive pole lug is connected to at least one end of the positive pole piece body along the width direction. According to the winding battery core provided by the embodiment of the invention, the migration resistance of lithium ions is reduced, the lithium precipitation nearby the first protective layer is reduced, and the phenomenon of contact short circuit caused by the penetration of lithium dendrites through the diaphragm is avoided.

Inventors

ZHANG QIANG
YE HAISONG
LIU RONGJIANG
HUANG BINBIN

Assignees

惠州亿纬锂能股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260213

Claims (15)

1. A coiled electrical cell, comprising: The negative electrode plate comprises a negative electrode plate body, a negative electrode tab and a first protection layer, wherein the negative electrode tab is connected to at least one end of the negative electrode plate body along the width direction, the first protection layer covers the joint of the negative electrode tab and the negative electrode plate body, and the first protection layer is an ion-conducting layer; The positive pole piece comprises a positive pole piece body and a positive pole lug, wherein the positive pole lug is connected to at least one end of the positive pole piece body along the width direction; And the diaphragm is clamped between the positive pole piece and the negative pole piece.
2. The wound cell of claim 1, wherein the negative tab is welded to the negative tab body.
3. The wound cell of claim 1, wherein the first protective layer is a porous ion-conducting gel paper and/or the first protective layer is formed with a plurality of ion-conducting pores for the passage of ions.
4. The wound cell of claim 3, wherein the first protective layer comprises a stacked substrate layer and a glue layer for adhesively securing the first protective layer to the negative electrode tab body, the ion-conducting apertures extending through the substrate layer and the glue layer in a thickness direction of the first protective layer.
5. The wound cell of claim 4, wherein the substrate layer is a polyethylene or polypropylene material.
6. The wound cell of claim 1, wherein the positive electrode tab further comprises a second protective layer covering the positive electrode tab and positive electrode tab body junction.
7. The wound cell of claim 6, wherein the second protective layer is a non-ion conductive layer and/or the second protective layer is a gummed paper.
8. The winding cell according to claim 7, wherein the first protective layer is provided on both sides of the negative electrode sheet in the thickness direction, and/or the second protective layer is provided on both sides of the positive electrode sheet in the thickness direction.
9. The wound cell of claim 7, wherein the first protective layer has a length W1,2mm < W1 < 25mm, the first protective layer has a width L1,5mm < L1 < 45mm, and/or the second protective layer has a length W2,4mm < W2 < 35mm, and the second protective layer has a width L2,7mm < L2 < 55mm.
10. The winding battery cell according to claim 7, wherein the length of the negative electrode tab along the length direction of the negative electrode sheet body is A1, the length of the first protective layer along the length direction of the negative electrode sheet body is W1, the ratio of W1 to A1 is 1-2, the length of the positive electrode tab along the length direction of the positive electrode sheet body is A2, and the length of the second protective layer along the length direction of the positive electrode sheet body is W2, and the ratio of W2 to A2 is 1-2.
11. The winding cell according to any one of claims 7 to 10, wherein a position of the negative electrode tab body corresponding to the positive electrode tab is a positive electrode tab corresponding region, the positive electrode tab corresponding region is provided with a third protection layer, and the third protection layer is an ion-conducting layer.
12. The wound cell of claim 11, wherein the negative electrode tab comprises a negative electrode active material layer, the negative electrode active material layer covers two side surfaces of the negative electrode tab body in a thickness direction, a connecting area between the negative electrode tab body and the negative electrode tab is a negative electrode empty foil area, the negative electrode active material layer covers other areas of the negative electrode tab body except for the negative electrode empty foil area, and the third protective layer covers one side of the negative electrode active material layer facing away from the negative electrode tab body.
13. The winding cell according to any one of claims 1 to 10, wherein the positive electrode sheet includes a positive electrode active material layer, the positive electrode active material layer covers both side surfaces of the positive electrode sheet body in a thickness direction, a connection region between the positive electrode sheet body and the positive electrode tab is a positive electrode empty foil region, the positive electrode active material layer covers other regions of the positive electrode sheet body excluding the positive electrode empty foil region, a position of the positive electrode sheet body corresponding to the negative electrode tab is a negative electrode tab corresponding region, a fourth protection layer is provided on a surface of the negative electrode tab corresponding region, the fourth protection layer covers a side of the positive electrode active material layer facing away from the positive electrode sheet body, and the fourth protection layer is a non-conductive ion layer.
14. A battery cell, comprising: A housing; The wound cell of any one of claims 1-13, the wound cell disposed within the housing.
15. A battery device, characterized by comprising: A case; A plurality of battery cells, located in the box, the battery cells being according to claim 14.

Description

Winding cell, battery cell and battery device Technical Field The invention relates to the field of batteries, in particular to a winding electric core, a battery cell and a battery device. Background In a winding cell formed by connecting a pole piece and a pole lug, burrs and/or welding bulges on the pole lug may puncture a diaphragm between the positive pole piece and the negative pole piece, so that the positive pole piece and the negative pole piece are in contact short circuit. In the related art, protective gummed paper is generally adhered to the connection part of the pole piece and the tab, however, lithium ions can be separated out from the edge of the protective gummed paper to form lithium dendrites in the charging process, and the lithium dendrites can puncture the diaphragm to cause the contact short circuit between the positive pole piece and the negative pole piece. Accordingly, improvements are needed. Disclosure of Invention The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, an object of the present invention is to provide a winding battery cell, in which lithium ions migrating from a positive electrode plate to a negative electrode plate can penetrate through a first protective layer and be inserted into the negative electrode plate in a charging process, so as to reduce migration resistance of the lithium ions, reduce lithium precipitation phenomenon near the first protective layer, and avoid contact short circuit phenomenon between the positive electrode plate and the negative electrode plate caused by penetration of lithium dendrites through a diaphragm. The invention also provides a battery cell comprising the winding cell. The invention also provides a battery device comprising the battery cell. The winding battery cell comprises a negative electrode plate, a positive electrode plate and a diaphragm, wherein the negative electrode plate comprises a negative electrode plate body, a negative electrode tab and a first protection layer, the negative electrode tab is connected to at least one end of the negative electrode plate body in the width direction, the first protection layer covers the joint of the negative electrode tab and the negative electrode plate body, the first protection layer is an ion guide layer, the positive electrode plate comprises a positive electrode plate body and a positive electrode tab, the positive electrode tab is connected to at least one end of the positive electrode plate body in the width direction, and the diaphragm is clamped between the positive electrode plate and the negative electrode plate. According to the winding battery core, the first protection layer covers the joint of the negative electrode tab and the negative electrode tab body, burrs and/or welding bulges on the negative electrode tab are prevented from being pierced by the burrs and/or welding bulges to cause internal short circuit of the battery, and lithium ions migrating from the positive electrode tab to the negative electrode tab can penetrate the first protection layer and be embedded into the negative electrode tab in the charging process by using the first protection layer as an ion conducting layer, so that migration resistance of the lithium ions is reduced, lithium precipitation phenomenon near the first protection layer is reduced, and the contact short circuit phenomenon between the positive electrode tab and the negative electrode tab caused by piercing the diaphragm by lithium dendrites is avoided. According to some embodiments of the invention, the negative tab is welded to the negative tab body. According to some embodiments of the invention, the first protective layer is a porous ion-conducting adhesive tape and/or the first protective layer is formed with a plurality of ion-conducting apertures for the passage of ions. According to some embodiments of the invention, the first protective layer comprises a base material layer and a glue layer stacked, the glue layer is used for adhesively fixing the first protective layer to the negative electrode plate body, and the ion guide holes penetrate through the base material layer and the glue layer along the thickness direction of the first protective layer. According to some embodiments of the invention, the substrate layer is made of polyethylene or polypropylene. According to some embodiments of the invention, the second protective layer is a non-ion conductive layer and/or the second protective layer is a gummed paper. According to some embodiments of the invention, the positive electrode tab further comprises a second protective layer covering the junction of the positive electrode tab and the positive electrode tab body. According to some embodiments of the invention, the first protection layer is arranged on two sides of the negative electrode plate along the thickness direction, and/or the second protection layer is arranged on two sides of the positive el