Preparation and performance of poly(ethylene oxide)-based composite solid electrolyte for all solid-state lithium batteries

Poly(ethylene oxide)-based solid electrolyte is attractive for using in all solid-state lithium batteries. However, the polymer has a certain degree of crystallization, which is adverse to the conduction of lithium ions. In order to overcome this drawback, a flexible composite polymer electrolyte (CPE) containing TiO2 nanoparticles is elaborately designed and synthesized by tape casting method. The effects of different molar ratios of EO: Li and mass fraction of TiO2 on the physical and electrochemical performances are carefully studied. The results show the CPE10 having 10 wt % TiO2 has the lowest degree of crystallinity of 9.04%, the lowest activation energy of 8.63 x 10(-5) eV mol(-1). Besides, the CPE10 shows a lower polarization and higher decomposition voltage. Thus, prepared all solid-state battery LiFePO4/CPE10/Li shows a high initial capacity of 160 mAh g(-1) at 0.1 C, 134 mAh g(-1) at 0.5 C and higher capacity retention of 93.2% after 50 cycles at 0.5 C (1 C = 170 mAh g(-1)). (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47498.