END CAP ASSEMBLY, BATTERY CELL, BATTERY, AND ELECTRICAL DEVICE

1 . An end cap assembly applicable to a battery cell, comprising:

a cover plate, configured to close a housing of the battery cell;

a terminal plate, located on a side of the cover plate, the side being away from the housing;

a first insulation component, at least partially located between the terminal plate and the cover plate;

an electrode terminal, penetrating the cover plate and the first insulation component, connected to the terminal plate, and configured to input or output electrical energy; and

a sealing element, comprising a sealing portion and a connecting portion connected to the sealing portion, wherein the sealing portion is disposed between a first insulation component and the cover plate to form a sealing region around the electrode terminal;

wherein at least one of the first insulation component or the cover plate comprises an accommodation recess, and at least a part of the connecting portion is accommodated in the accommodation recess to fixedly fit the accommodation recess.

2 . The end cap assembly according to claim 1 , wherein the connecting portion has a columnar shape, and all cross-sections of the connecting portion are equal in area.

3 . The end cap assembly according to claim 1 , wherein:

the connecting portion comprises a first connecting section and a second connecting section;

the second connecting section is located on a side of the first connecting section, the side being away from the sealing portion; and

a cross-sectional area of the second connecting section is larger than a cross-sectional area of the first connecting section.

4 . The end cover assembly according to claim 3 , wherein:

the cover plate comprises a first surface and a sealing recess recessed in the first surface;

at least a part of the sealing portion is accommodated in the sealing recess;

the first insulation component comprises a second surface opposite to the first surface and an accommodation recess recessed in the second surface; and

the accommodation recess comprises an opening on both the second surface and a third surface of the first insulation component, wherein the third surface is located on a side away from the cover plate.

5 . The end cap assembly according to claim 3 , wherein a longitudinal section of the accommodation recess is in an inverted L shape or a T shape.

6 . The end cap assembly according to claim 1 , wherein the sealing portion at least partially covers an opening of the accommodation recess.

7 . The end cap assembly according to claim 6 , wherein the sealing portion fully covers the opening of the accommodation recess, and a width of the sealing portion is greater than a width of the opening of the accommodation recess.

8 . The end cap assembly according to claim 1 , wherein the connecting portion is in fit with an inner wall of the accommodation recess without clearance.

9 . The end cap assembly according to claim 1 , wherein the sealing portion has a closed ring structure, and the accommodation recess comprises a plurality of holes spaced apart along a circumferential direction of the closed ring structure.

10 . The end cap assembly according to claim 9 , wherein the plurality of holes are arranged symmetrically with respect to a centerline of the closed ring structure in at least one direction.

11 . The end cap assembly according to claim 9 , wherein a sum of lengths of the plurality of holes in the circumferential direction of the closed ring structure is less than a sum of lengths of all solid parts between every two adjacent holes in the circumferential direction of the closed ring structure.

12 . The end cap assembly according to claim 1 , wherein a cross-sectional shape of the accommodation recess comprises at least one of a polygon, a circle, an ellipse, or a sector ring.

13 . The end cap assembly according to claim 1 , wherein the cover plate comprises a first through-hole, the first insulation component comprises a second through-hole, the electrode terminal penetrates the first through-hole and the second through-hole along a thickness direction of the cover plate, and both the first through-hole and the second through-hole are located in the sealing region.

14 . The end cap assembly according to claim 1 , wherein a material of the sealing element is different from a material of the at least one of the first insulation component or the cover plate.

15 . The end cap assembly according to claim 14 , wherein the sealing element is formed in one piece together with the at least one of the first insulation component or the cover plate through an injection molding process.

16 . The end cap assembly according to claim 14 , wherein hardness of the material of the sealing element is lower than hardness of the material of the at least one of the first insulation component or the cover plate.

17 . A battery cell, comprising:

an electrode assembly;

a housing, configured to accommodate the electrode assembly, wherein an end portion of the housing is opened; and

the end cap assembly according to claim 1 , wherein the end cap assembly is disposed at the end portion of the housing.

18 . The battery cell according to claim 17 ,

wherein the end cap assembly is a negative end cap assembly of the battery cell located on one side of the electrode assembly;

the battery cell further comprising:

a positive end cap assembly, located on another side of the electrode assembly;

wherein both end portions of the housing are opened, and the negative end cap assembly and the positive end cap assembly fit and cover the two end portions of the housing respectively.

19 . The battery cell according to claim 18 , wherein the positive end cap assembly comprises an injection port.

20 . A battery, comprising the battery cell according to claim 17 .