In the structure of lithium battery, the membrane is an important internal component. The performance of the separator determines the interface structure, internal resistance and other characteristics of the battery, and directly affects the capacity, cycle and safety performance of the battery. A good separator plays an important role in improving the comprehensive performance of the battery. The main function of the separator is to separate the positive and negative electrodes of the battery and prevent electrolyte ions from passing through due to contact between the two electrodes. The membrane material is non-conductive, and its physical and chemical properties have a great impact on the performance of the battery. The type of battery pack is different, and the membrane used is also different. For the lithium battery pack, since the electrolyte is an organic solvent system, a membrane material resistant to organic solvents is required, and generally a high-strength membrane polyolefin porous membrane is used.
PET film
PET film, also known as high temperature resistant polyester film, has excellent heat resistance, cold resistance, oil resistance and chemical resistance. According to its function, it can be divided into pet high gloss film, chemical coating film, polyester antistatic film, polyester heat sealing film, polyester heat shrinkable film, aluminized polyester film, etc.
Battery film cutting
Traditional processing mostly adopts die cutting, but for manufacturers with small batch, multiple varieties and high processing accuracy requirements, the cost of mold opening is high and the accuracy is not up to standard. Therefore, the new technology laser cutting is more and more used in various polyester film processing because of its unique advantages such as simple operation, automatic operation and fine processing. For the cutting of some films, the red laser will turn yellow. Therefore, it goes beyond the characteristics of laser using violet laser cold processing and low heat, and the use of ultraviolet laser to cut polyester film just makes up for the shortage of red light processing.