1. What is the material of lithium battery separator?
The main function of lithium battery separator is to separate the positive and negative electrodes of the battery, to prevent short circuit caused by contact between the two electrodes, and to let electrolyte ions pass through. The material of the separator is not conductive, and its physical and chemical properties have great influence on the performance of the battery. Different types of batteries use different separators. For lithium battery series, because the electrolyte is an organic solvent system, it is necessary to have a separator material resistant to organic solvents, and generally a high-strength thin polyolefin porous membrane is used.
Lithium battery separator materials mainly include single-layer PP, single-layer PE, PP+ ceramic coating, PE+ ceramic coating, double-layer PP/PE, double-layer PP/PP, triple-layer PP/PE/PP and so on. The first two types of products are mainly used in the field of 3C small batteries, while the latter is mainly used in the field of power lithium batteries. Among the separator materials for power lithium batteries, double-layer PP/PP separator materials are mainly produced by domestic enterprises and used in Chinese mainland, mainly because domestic enterprises have not yet made PP and PE into double-layer composite films. The separators used in global automotive lithium batteries are mainly three-layer PP/PE/PP, double-layer PP/PE, PP+ ceramic coating, PE+ ceramic coating and other separator materials.