BOTTOM SUPPORT FOR BATTERY CELL, BATTERY CELL, BATTERY, AND ELECTRIC DEVICE

1 . A bottom support for supporting a jelly roll of a battery cell, the bottom support comprising a bottom plate, wherein the bottom plate comprises a central region and a peripheral region surrounding the central region;

wherein the bottom plate is constructed to form at least one recessed group, and a recessed area increases gradually among the recessed group(s) in a direction from the peripheral region to the central region of the bottom plate.

2 . The bottom support according to claim 1 , wherein

each recessed group comprises a plurality of recessed parts arranged in sequence along the direction from the peripheral region to the central region, all recessed parts in a same surrounding direction in each recessed group are defined as a row, and a sum of areas of all recessed parts in a same row is defined as a sub-recessed area; and

a sum of sub-recessed areas of all rows is the recessed area of each recessed group, and the sub-recessed area increases gradually among the rows in the direction from the peripheral region to the central region of the bottom plate.

3 . The bottom support according to claim 2 , wherein the central region of the bottom plate is constructed to form a central recessed part, wherein the central recessed part has a recessed area larger than the largest sub-recessed area in each recessed group.

4 . The bottom support according to claim 3 , wherein

the recessed group comprises at least two groups arranged in sequence along a surrounding direction of the peripheral region; and

any two recessed groups located on two opposite sides of the central recessed part are symmetrically distributed with respect to a central line of the central recessed part.

5 . The bottom support according to claim 4 , wherein two adjacent recessed parts located in a same surrounding direction of the peripheral region in two adjacent recessed groups are correspondingly communicated.

6 . The bottom support according to claim 1 , further comprising a side plate fitted to the bottom plate, wherein the side plate is consecutively disposed in a surrounding direction of the peripheral region and together with the bottom plate, encloses a limiting space for limiting the jelly roll.

7 . The bottom support according to claim 6 , wherein the side plate is constructed to form a first communicating hole communicating with the limiting space.

8 . The bottom support according to claim 1 , further comprising an upright post, wherein the upright post is fitted to the bottom plate and is constructed for winding the jelly roll.

9 . The bottom support according to claim 8 , wherein the upright post has a hollow structure, and an outer wall of the upright post is provided with a second communicating hole communicating with the inside of the upright post.

10 . A battery cell, comprising:

a housing;

a jelly roll; and

the bottom support according to claim 1 ,

wherein the jelly roll and the bottom support are both arranged in the housing, and the bottom plate of the bottom support is clamped between the jelly roll and an inner bottom wall of the housing.

11 . A battery, comprising:

a box; and

the battery cell according to claim 1 ,

wherein the battery cell is accommodated in the box.

12 . An electric device, comprising the battery according to claim 11 , wherein the battery is configured to supply electrical energy.