BATTERY CELL, BATTERY AND ELECTRICAL DEVICE

1 . A battery cell, comprising:

a first surface, a first region of an edge of the first surface being recessed to form a first recess;

a second surface, the first surface and the second surface being perpendicular to a first direction; and

a first electrode terminal arranged at the second surface and protruding from the second surface in the first direction and facing the first recess;

wherein, in the first direction, a depth of the first recess is larger than a height of the first electrode terminal, and a projection area of the first recess on the first surface is larger than a projection area of the first electrode terminal on the first surface.

2 . The battery cell according to claim 1 , wherein in the first direction, a difference between a dimension of the battery cell and a dimension of the first recess of the battery cell is greater than or equal to 2 mm.

3 . The battery cell according to claim 1 , wherein a dimension of the first recess on the first surface along a second direction is greater than or equal to 12 mm, the second direction is perpendicular to a third surface of the battery cell, and the third surface is perpendicular to the first surface and the second surface.

4 . The battery cell according to claim 3 , wherein a dimension of the first recess on the first surface along a third direction is greater than or equal to 15 mm, and the third direction is perpendicular to the first direction and the second direction.

5 . The battery cell according to claim 1 , further comprising:

a case; and

an end cover;

wherein the case is configured to accommodate an electrode assembly of the battery cell, the end cover covers the case to enclose the electrode assembly in the case, a bottom wall of the case forms the first surface of the battery cell, and the end cover forms the second surface of the battery cell.

6 . The battery cell according to claim 5 , wherein a region of the end cover corresponding to the electrode assembly protrudes in a direction facing away from the case, so as to form a groove on a side of the end cover facing the case.

7 . The battery cell according to claim 6 , wherein the groove is configured to position the electrode assembly in a process of assembling the electrode assembly.

8 . The battery cell according to claim 6 , wherein a contour line between an edge region of the end cover and the groove is configured to position a welding trajectory in a process of welding the case and the end cover.

9 . The battery cell according to claim 8 , wherein a distance between the contour line and the welding trajectory is greater than 0.5 mm.

10 . The battery cell according to claim 6 , wherein a depth of the groove is between 0.4 mm and 3 mm.

11 . The battery cell according to claim 6 , wherein on a cross section of a plane perpendicular to the first direction, a dimension of the groove is greater than or equal to a dimension of the electrode assembly.

12 . The battery cell according to claim 1 , wherein:

a second region of the edge of the first surface is recessed to form a second recess, the first region is located at a first end of the first surface in a second direction, the second region is located at a second end of the first surface in the second direction, a second electrode terminal of the battery cell protrudes from the second surface of the battery cell in the first direction and faces the second recess, and a polarity of the second electrode terminal is opposite to a polarity of the first electrode terminal; and

in the first direction, a depth of the second recess is larger than a height of the second electrode terminal, and a projection area of the second recess on the first surface is larger than a projection area of the second electrode terminal on the first surface.

13 . A battery, comprising the battery cell according to claim 1 .

14 . An electrical device, comprising the battery cell according to claim 1 , wherein the battery cell is configured to provide electric energy.