Preparation of new composite polymer electrolyte for long cycling all-solid-state lithium battery

Abstract

A new composite solid polymer electrolyte (SPE) PPC-PEO 10 W [5:5]-1%wt LAGP with high conductivity is successfully prepared. The relationships between the conductivities and compositions are systematically characterized. The optimal composite polymer electrolyte presents a maximum conductivity of 8.39 × 10−4 S cm−1 with a 4.5 V electrochemical window and excellent stability with lithium at 60 °C. The relevant mechanisms of the conductivity improvement are studied. Finally, the all-solid-state lithium battery (ASSLB) LiFePO4/Li cells are assembled and the initial discharge specific capacities of the cells are 152.9, 135.1, 114.9, and 99.1 mAh g−1 at 0.1, 0.2, 0.5, and 1 C at 60 °C, respectively. The LFP/Li cells show good discharge retentions of 88.2% (~ 103.1 mAh g−1) after 700 cycles at 0.5 C and 73.4% after 500 cycles at 1 C. This work presents a promising composite polymer electrolyte for ASSLBs, which is a highly attractive candidate for practical application.