CN-224232841-U - Battery pack

CN224232841UCN 224232841 UCN224232841 UCN 224232841UCN-224232841-U

Abstract

The utility model discloses a battery pack which comprises a battery cell group, a pre-tightening belt, a cylinder, a first end plate and a second end plate, wherein the first end plate is propped against one end of the battery cell group, the second end plate is arranged at intervals with the other end of the battery cell group to form an adjusting gap, the pre-tightening belt is wound on the peripheral walls of the first end plate and the second end plate, a shell of the cylinder is fixedly arranged on the second end plate, and a piston end of the cylinder passes through the adjusting gap to prop against the battery cell group. The first end plate and the second end plate at two ends of the battery cell group are fastened through the pre-tightening belt, the adjusting gap formed by the second end plate and the battery cell group at intervals provides space for displacement of the cylinder piston, the thickness of the battery cell group gradually increases along with the progress of circulation or the deepening of aging in the whole life cycle, so the pre-tightening force of the pre-tightening belt gradually increases, at the moment, the cylinder drives the piston to retract to release the excessive pressure exerted by the pre-tightening belt, and the damage of the battery cell group caused by the excessive pre-tightening force is avoided.

Inventors

ZHOU JING
LI PING
XIANG LIANGSHUN
XIANG JIAYUAN

Assignees

浙江南都电源动力股份有限公司
杭州南都动力科技有限公司

Dates

Publication Date: 20260512
Application Date: 20250427

Claims (8)

1. The utility model provides a battery package, its characterized in that includes electric core group, pretension area, cylinder, first end plate and second end plate, first end plate offsets with electric core group one end and leans on, and the second end plate sets up with electric core group other end interval in order to form the regulation clearance, pretension area is around locating first end plate and second end plate peripheral wall, the casing fixed mounting of cylinder is in the second end plate, and the piston end of cylinder passes adjust clearance and electric core group and support and lean on.
2. The battery pack according to claim 1, wherein the piston end of the cylinder is provided with a pressing plate, and the area of the pressing plate is consistent with the area of the end, facing the pressing plate, of the battery cell group.
3. The battery pack according to claim 1, further comprising a housing, wherein the battery cell group, the pre-tightening belt, the first end plate and the second end plate are all arranged inside the housing, the cylinder is connected with a high-pressure gas cylinder through a gas pipe, the gas pipe is provided with a gas outlet valve, a gas inlet valve and a gas pressure acquisition instrument, a gas inlet end of the gas inlet valve is connected with the high-pressure gas cylinder, a gas outlet end of the gas inlet valve is connected with the cylinder, a gas inlet end of the gas outlet valve is connected with the cylinder, a gas outlet end of the gas outlet valve is connected with the housing, or a gas outlet end of the gas outlet valve is connected with the housing outside, and the gas pressure acquisition instrument is used for acquiring the gas pressure of the cylinder.
4. The battery pack of claim 1, wherein the distance of movement of the cylinder piston end is 1% -10% of the thickness of the cell stack.
5. A battery pack according to claim 3, wherein the high-pressure gas cylinder is mounted at the bottom of the housing, and the high-pressure gas cylinder is located below the gas cylinder, and the high-pressure gas cylinder is connected with the gas cylinder along the inner wall of the housing through the gas pipe.
6. A battery pack according to claim 3, wherein the gas stored in the high-pressure gas cylinder is inert gas, the inert gas is nitrogen or argon, and the pressure-bearing strength of the high-pressure gas cylinder is greater than 2MPa.
7. A battery pack according to claim 3, wherein the exhaust valve outlet end is provided with a muffler for reducing exhaust noise.
8. The battery pack of claim 1, wherein the pre-tightening strap is a plurality of steel straps disposed in parallel, the plurality of steel straps being evenly distributed along the circumference of the first end plate and the second end plate.

Description

Battery pack Technical Field The utility model relates to the technical field of batteries, in particular to a battery pack. Background Although lithium batteries have advantages such as high energy density and long cycle life, they are still required to meet the severe demands for cycle life and safety in practical applications. In the module assembly process, in order to reduce the internal resistance of the battery and ensure the tight adhesion of the electrodes, a fixed pretightening force is usually applied by adopting an end plate and a steel belt in a matching way. However, the rigidity pre-tightening force fluctuates with the thickness change during the charge and discharge of the battery cell, and the volume expansion of the active material is gradually increased due to the increase of the cycle times. This phenomenon is prone to cause mismatch of pretightening force and cell expansion, resulting in cell mechanical fatigue, interface degradation, and further shortening battery life and affecting performance stability. Disclosure of utility model Aiming at the technical problems, the utility model provides a battery pack, which drives a piston to retract through a cylinder so as to release the excessive pressure applied by a pre-tightening belt and avoid the damage of a battery cell group caused by the excessive pre-tightening force. The battery pack comprises a battery cell group, a pre-tightening belt, an air cylinder, a first end plate and a second end plate, wherein the first end plate is abutted against one end of the battery cell group, the second end plate is arranged at intervals with the other end of the battery cell group to form an adjusting gap, the pre-tightening belt is wound on the peripheral walls of the first end plate and the second end plate, a shell of the air cylinder is fixedly arranged on the second end plate, and a piston end of the air cylinder passes through the adjusting gap and is abutted against the battery cell group. Optionally, the cylinder piston end is equipped with the clamp plate, the clamp plate area is consistent with the area of electricity core group towards clamp plate one end. Optionally, still include the casing, inside electric core group, pretension area, first end plate, second end plate all located the casing, the cylinder has the high-pressure gas cylinder through the trachea connection, the trachea is equipped with discharge valve, admission valve and atmospheric pressure collection appearance, the inlet end and the high-pressure gas cylinder of admission valve are connected, and the end of giving vent to anger of admission valve is connected with the cylinder, the inlet end and the cylinder of discharge valve are connected, the end and the casing internal connection of giving vent to anger of discharge valve, or the end and the casing external connection of giving vent to anger of discharge valve, the atmospheric pressure collection appearance is used for gathering the atmospheric pressure of cylinder. Optionally, the moving distance of the piston end of the air cylinder is 1% -10% of the thickness of the battery cell group. Optionally, the high-pressure gas cylinder is installed in the casing bottom, and the high-pressure gas cylinder is located the cylinder below, pass through between high-pressure gas cylinder and the cylinder the trachea is followed shells inner wall and is connected. Optionally, the gas stored in the high-pressure gas cylinder is inert gas, the inert gas is nitrogen or argon, and the pressure bearing strength of the high-pressure gas cylinder is greater than 2MPa. Optionally, a muffler for reducing exhaust noise is arranged at the exhaust end of the exhaust valve. Optionally, the pretensioning belt is a plurality of steel belts arranged in parallel, and the plurality of steel belts are uniformly distributed along the circumference of the first end plate and the second end plate. The utility model has the beneficial effects that the first end plate and the second end plate at the two ends of the battery cell group are fastened through the pre-tightening belt, the adjusting gap formed by the second end plate and the battery cell group at intervals provides space for the displacement of the cylinder piston, and the thickness of the battery cell group is gradually increased along with the progress of circulation or the deepening of aging in the whole life cycle of the battery cell group, so the pre-tightening force of the pre-tightening belt is gradually increased, and at the moment, the cylinder drives the piston to retract to release the excessive pressure exerted by the pre-tightening belt, so that the damage of the battery cell group caused by the excessive pre-tightening force is avoided. Drawings Fig. 1 is a schematic structural view of a battery pack according to an embodiment of the present utility model; Fig. 2 is a schematic diagram of an intake valve and an exhaust valve of a battery pack according to an embodiment of the