Poly(vinylidene fluoride)/SiO2 composite membrane separators for high-performance lithium-ion batteries to provide battery capacity with improved separator properties

Abstract

LIBs with improved specific capacity even more than theoretical capacity that is provided by poly (vinylidene fluoride) and silicon dioxide (PVDF/SiO2) nanofiber composite membrane separator is presented in our study. The experiment results are in agreement with simulation analysis that Si can substitute P in the LiFePO4 during the charge-discharge process and lead a great electrochemical performance. It provides a new approach to significantly improve the overall electrochemical performance. This can be described as the capacity of 175 mAh/g at 0.1 C; 160.7 mAh/g at 0.5 C and subsequent residual capacity is 168.6 mAh/g at 0.2 C after long-term cycles of 300 times and the coulombic efficiency is 98.22%. Meanwhile, the PVDF/SiO2 separators are exhibited higher porosity (131.33%) and electrolyte uptake (1514.79%) than commercial PP separator, and also evaluated reduced interfacial resistance and higher thermal property that the initial decomposition temperature is 389.05 °C. The PVDF/SiO2 separators with better performance than commercial separator apply to conventional lithium-ion batteries leads to improved electrochemical performance obviously, and can be more prospective for LIBs after multiple modified preparations.