Follow me on:
When the stacking machine is used in the production of pouch batteries, it can achieve higher performance and safety than cylindrical and prismatic batteries. The stacking machine stacks the positive electrode sheet, separator, and negative electrode sheet in order to form a small battery cell, and then stacks the small battery cells in parallel to form a large battery cell. The advantages of the cells produced by the stacking process are: Since it is equivalent to multiple small electrode sheets connected in parallel, the internal resistance is low and the discharge platform is high; the stress area between the diaphragm of the cell electrode sheet is consistent, and there is no obvious stress concentration point; the internal space is fully utilized, and the volume specific capacity and energy density are higher; the stacking process is equivalent to the parallel connection of multi-electrode sheets, which is easier to complete high-current discharge in a short time, and has good rate performance.
The disadvantages of the stacking process are high operating requirements, cumbersome production control, high defective rate, and the biggest bottleneck is low production efficiency. At present, most of the equipment in China is duplex, and the efficiency is generally 0.5-0.8 seconds/piece, and that of leading enterprises can reach 0.2-0.3 seconds/piece. The electrochemical performance of the battery cell produced by the winding process is slightly worse than that of the laminated type, but the advantage is that it has a high degree of automation, is easy to manufacture, and is suitable for large-scale production, therefore, square batteries on the market, especially cylindrical batteries, are generally produced by winding technology.