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

A new composite solid polymer electrolyte (SPE) PPC-PEO 10W [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 8.39x10(-4)Scm(-1) with a 4.5 V electrochemical window and excellent stability with lithium at 60 degrees 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 99.1mAhg(-1) at 0.1, 0.2, 0.5, and 1C at 60 degrees C, respectively. The LFP/Li cells show good discharge retentions of 88.2% (similar to 103.1mAhg(-1)) after 700cycles at 0.5C and 73.4% after 500cycles at 1C. This work presents a promising composite polymer electrolyte for ASSLBs, which is a highly attractive candidate for practical application.