High Conductive Composite Polymer Electrolyte via in Situ UV-Curing for All-Solid-State Lithium Ion Batteries

All-solid-state lithium ion batteries are considered to be one of the best candidates for next generation batteries due to the high safety and energy density, but there is still a severe challenge for seeking the high-performance solid electrolytes with high ionic conductivity. Most importantly, the huge resistance at the electrode/electrolyte interface limits their applications. In this work, we investigate an in situ building method of a solid electrolyte, which constructs a composite electrolyte on the cathode by UV-curing and reduces the interfacial impedance by 69.1%. The solid electrolyte shows a decent ionic conductivity of 2.21 x 10(-5) S cm(-1) at 25 degrees C and presents a wide electrochemical stability window (>4.7 V vs Li+/Li). The all-solid-state LiFePO4/Li cell displays a high discharge capacity of 147 mAh g(-1) and good capacity retention of similar to 82% in 100 cycles under 0.1 C at room temperature. The strategy for in situ fabrication of a composite polymer electrolyte shows a promising way for the application of all-solid-state lithium batteries.