CN-224217594-U - Battery module

CN224217594UCN 224217594 UCN224217594 UCN 224217594UCN-224217594-U

Abstract

The utility model provides a battery module which comprises a shell and a battery cell group, wherein the shell at least comprises an end plate arranged in the thickness direction of the battery cell group, a plate spring is arranged in the end plate, the middle part of the plate spring protrudes towards the battery cell group, the plate spring is overlapped by a plurality of arc-shaped spring pieces with different radiuses, two ends of the arc-shaped spring pieces farthest from the battery cell group are provided with pressure release lug plates, and the pressure release lug plates are contacted with the inner wall of a second main plate in the end plate. The plate spring, the elastic insulating pad and the end plate can reasonably absorb the expansion displacement of the battery cell unit, give the battery cell unit reasonable constraint force to antagonize the expansion trend of the battery cell unit and inhibit the middle part of the battery cell unit from expanding, and the pressure release lug plate can release the pressure bearing part of the plate spring to the edge part of the large surface of the second main plate, adjust the stress condition of each part of the large surface of the second main plate, avoid the deformation out of tolerance of the second main plate and cooperatively improve the cycle performance and the safety performance of the battery cell.

Inventors

QIAN LIJIA
LI DE
GUO BAOHUI
DONG JIUBAO

Assignees

天津中电新能源研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20250121

Claims (7)

1. A battery module is characterized by comprising a shell and a battery cell group, wherein the shell at least comprises an end plate arranged in the thickness direction of the battery cell group, a plate spring is arranged in the end plate, the middle part of the plate spring protrudes towards the battery cell group, the plate spring is overlapped by a plurality of arc-shaped spring pieces with different radiuses, the middle part of the arc-shaped spring piece closest to the battery cell group is contacted with the inner wall of one side of the end plate, and pressure release lugs are arranged at the two ends of the arc-shaped spring piece farthest from the battery cell group and are contacted with the inner wall of the other side of the end plate.
2. The battery module according to claim 1, wherein the pressure release ear plate is parallel to the end plate inner wall against which it abuts, and a contact portion of the pressure release ear plate and the end plate inner wall is near an edge of the end plate inner wall.
3. The battery module according to any one of claims 1 to 2, wherein a plurality of the plate springs are arranged in the height direction of the cell stack, and the stiffness of the plate springs located in the middle is larger than or equal to the stiffness of the plate springs located in other portions.
4. The battery module according to claim 3, wherein the end plate includes a first main plate and a second main plate which are arranged in parallel, side ends of the first main plate and the second main plate are connected through different side plates, respectively, the plate-shaped spring is located between the first main plate and the second main plate, and the first main plate contacts an end face in a thickness direction of the battery cell group.
5. The battery module of claim 4, wherein a thickness of the first main plate is < a thickness of the second main plate.
6. The battery module according to any one of claims 1-2 and 4-5, wherein the housing includes side pull plates configured on both widthwise sides of the battery cell stack, and both ends are respectively connected to different end plates to fasten the end plates by drawknots.
7. The battery module according to claim 6, wherein the cell group includes cell units and elastic insulating pads alternately arranged in a thickness direction thereof, and a large area of the elastic insulating pads is larger than or equal to a large area of the electrode group in the cell units.

Description

Battery module Technical Field The utility model relates to the technical field of electrochemical energy, in particular to a battery module. Background The lithium battery is widely applied to the new energy automobile industry and the energy storage industry, and when the lithium battery is used, the battery cells are generally stacked to form a module, and then the module is placed in a battery box for charge and discharge circulation. The lithium battery cell is internally provided with a pole group, the pole group is assembled by pole pieces, and the thickness direction of the pole group expands due to the thickening of the pole pieces along with the recycling of the battery box, so that the cell expands. The cell expansion can produce huge expansion pressure to the module end plate, and the cell is big to face the middle part and expands the displacement the biggest, leads to the big face middle part of end plate outwards to warp the biggest, causes the module size to be out of tolerance, even end plate fracture, if excessively improves the restraining force of module frame (including module end plate) to the cell, can influence the life cycle of cell, can initiate internal short circuit even, causes the cell to fire explosion. Besides increasing the rigidity of the module frame and increasing the pretightening force, other common practice in the industry is to reduce the rigidity of the middle part of the end plate, or add a square-shaped elastic gasket between the cells in the module, and reserve the expansion space of the middle part of the large surface of the cell, but the above methods can lead to the increase of the deformation of the pole pieces in the cells and reduce the cycle performance of the cells. Disclosure of utility model The present utility model is directed to a battery module for solving the above-mentioned problems in the background. The battery module comprises a shell and a battery cell group, wherein the shell at least comprises an end plate arranged in the thickness direction of the battery cell group, a plate-shaped spring is arranged in the end plate, and the middle part of the plate-shaped spring protrudes towards the battery cell group. Further, the plate spring is formed by overlapping a plurality of arc-shaped spring pieces with different radiuses, the middle part of the arc-shaped spring piece closest to the battery cell group is in protruding contact with the inner wall of one side of the end plate, and the two ends of the arc-shaped spring piece farthest from the battery cell group are provided with pressure release lug plates which are in contact with the inner wall of the other side of the end plate. Further, the pressure release lug plate is parallel to the abutting end plate inner wall, and the contact part of the pressure release lug plate and the end plate inner wall is close to the edge of the end plate inner wall. Further, a plurality of plate springs are arranged along the height direction of the battery cell group, and the rigidity of the plate springs positioned in the middle is larger than or equal to the rigidity of the plate springs positioned in other parts. Further, the end plate comprises a first main plate and a second main plate which are arranged in parallel, the side ends of the first main plate and the side ends of the second main plate are respectively connected through different side connection plates, the plate springs are located between the first main plate and the second main plate, and the first main plate is contacted with the end face of the battery cell group in the thickness direction. Further, the thickness of the first main plate is less than the thickness of the second main plate. Further, the shell comprises side pulling plates, the side pulling plates are arranged on the two wide sides of the battery cell group, and two ends of each side pulling plate are respectively connected with different end plates so as to fasten the end plates through drawknots. Further, the battery cell group comprises battery cell monomers and elastic insulating pads which are alternately arranged along the thickness direction of the battery cell group, and the large area of the elastic insulating pads is larger than or equal to the large area of the middle pole group of the battery cell monomers. The utility model has the advantages that based on the arrangement and selection of the plate spring, the elastic insulating pad and the end plate, the expansion displacement of the battery cell monomer can be reasonably absorbed, the reasonable constraint force is given to the battery cell monomer to antagonize the expansion trend of the battery cell monomer and inhibit the expansion of the middle part of the battery cell monomer, in addition, the pressure release lug plate can release the bearing pressure part of the plate spring to the edge part of the large surface of the second main plate, the stress condition of each part of the large surface of the secon