Solid polymer electrolytes reinforced by electrospun poly(ether imide) membrane for all-solid-state lithium batteries

Abstract

Poly(ε-caprolactone) (PCL)-based solid polymer electrolytes were prepared, and their electrochemical properties were investigated. The optimized polymer electrolyte showed ionic conductivities of 2.5 ⅹ 10-5 and 2.2 ⅹ 10-4 S/cm at room temperature and 55 ℃ and exhibited good electrochemical stability. To improve dimensional stability, PCL-based polymer electrolyte was infiltrated into thermally reinforced the porous electrospun poly(ether imide) (PEI) membrane. A solid-state Li/LiNi0.6Co0.2Mn0.2O2 cell assembled with PCL-based solid polymer electrolyte in electrospun PEI membrane exhibited an initial discharge capacity of 174.6 mAh/g and good capacity retention. Good cycling performance of the cell resulted from the high ionic conductivity and its good interfacial contacts with electrodes.