Key points of Power battery cover plate technology from component composition to five core functions

Structural components play a role in transmitting energy, carrying electrolyte, protecting safety, fixing and supporting batteries, and decorative appearance in lithium batteries. Depending on the application environment, they have specific functions such as connectivity, shock resistance, heat dissipation, corrosion resistance, anti-interference, and anti-static, which have a direct impact on the safety, sealing, and energy efficiency of lithium batteries. The hard shell structural components of lithium battery cells can be divided into cylindrical and square structural components, mainly including the shell Power battery cover plate, connection arrangement, etc. Among them, the cover plate plays an important role in the battery, but due to its complex structure, it is necessary to systematically sort out its components, production processes, and functions.

The square battery power battery cover plate and the cylindrical Battery cover plate have certain structural differences, but both contain several key components. The cover plate is mainly composed of the cover plate body, positive and negative poles, injection hole, explosion-proof valve (explosion-proof plate), flip plate and other components. These components work together through precision assembly to achieve the sealing, conductivity, pressure relief, and protection functions of the Battery aluminum safety cover set. Among them, the positive and negative poles are responsible for the import and export of current, the explosion-proof valve is used for pressure relief in abnormal situations, and the flipping piece provides a fuse protection mechanism.

The production process of Power battery cover plates mainly includes core processes such as stamping, welding, and injection molding. Stamping technology is used to form the main body of the cover plate and various metal structural components, ensuring dimensional accuracy and batch consistency; The welding process is mainly used for the connection of key parts such as pole and cover plate, connecting piece and pole, and has high requirements for welding strength and sealing; The injection molding process is used to shape plastic insulation parts, achieving electrical isolation between the pole and the Aluminum cover plate for batteries. The precision control of each process directly affects the final performance and reliability of the cover plate.

The cover plate integrates multiple core functions in lithium batteries, mainly including the following five aspects:

Firstly, the function of fixation and sealing. The Power battery cover plate is connected to the aluminum shell through laser welding, wrapping and fixing the bare cell to achieve sealing effect, preventing electrolyte leakage and external impurities from entering.

Secondly, the current conduction function. Inside the battery, the top cover pole, adapter piece, and battery cell ear are welded and connected to ensure the normal conduction of battery cell charging and discharging current; At the module level, the top pole and busbar are connected by laser welding or bolts to form a series parallel circuit.

Thirdly, the pressure relief function. When there is an abnormality in the battery and the internal air pressure increases to the set value, the Prismatic lithium battery lid explosion-proof valve will open to release pressure, effectively reducing the risk of explosion.

Fourth, the circuit breaker protection function. When the internal air pressure of the battery rises abnormally to a certain value, the Prismatic lithium battery canopy flip piece lifts up and comes into contact with the negative rivet block, causing a direct short circuit between the positive and negative poles of the top cover. At the same time, the aluminum connecting piece melts, quickly cutting off the current and preventing the accident from expanding.

Fifth, reduce electrochemical corrosion. The plastic on the positive electrode is made of conductive PPS material, ensuring a certain resistance between the positive electrode column and the top Prismatic lithium battery annex, thereby reducing the potential difference between the positive electrode column and the aluminum shell, preventing electrochemical corrosion of the top cover plate and aluminum shell, and improving product quality and service life.
 

The above content systematically summarizes the components, production processes, and five core functions of Power battery cover plates. If you need to further understand the specific design schemes of cover plates under different packaging systems or obtain technical parameters of customized structural components, please feel free to contact us at any time. We will provide you with professional technical support and product consulting services.