Comparative analysis of different separators for the electrochemical performances and long-term stability of high-power lithium-ion batteries

Abstract

As a critical component, high-performance separator is in urgent demand for the development of high-power lithium-ion battery (LIB). Herein, five commercial separators including cellulose, polyethylene terephthalate (PET), aramid nonwovens, and polypropylene (PP) and polypropylene/polypropylene (PP/PP) polyolefin membranes were investigated and used as high-power LIB separators. Due to the high porosity (70%), low air permeability, high electrolyte uptake and ionic conductivity (1.37 mS cm−1), excellent electrolyte wettability, and good heat resistance for cellulose separator, the corresponding LIBs exhibit the best comprehensive performance with low resistance, good rate capability of 91.8% retention at 10 C, long-term stability at 65 °C, and high capacity retention of 95.5% after 2000 cycles, indicating the promising application in LIBs with high power and long-term stability.