A new composite solid electrolyte PEO/Li10GeP2S12/SN for all-solid-state lithium battery

A new solid polymer electrolyte (SPE) PEO-LiTFSI-1%LGPS-10%SN is successfully prepared via a convenient method with low cost. The effect of SN on the ionic conductivity of PEO-based electrolyte is systematically investigated. It presents a maximum conductivity of 9.10   ×   10 −5   S·cm −1 at 25   °C, and a 15-fold ion conductivity enhancement in PEO-LiTFSI. It exhibits wide electrochemical window (0–5.5   V) and excellent compatibility with metallic Li. The LiFePO 4 /Li batteries exhibit a good cycling and rate performance under 40   °C, whose maximum discharge specific capacity at 0.1 C is 160.6   mAh·g −1 , and 94.7% can be retained after 60 cycles. At 0.5C, the maximum discharge specific capacity is 138.4   mAh·g −1 , and capacity retention close to 90% even after 100 cycles. The reasons of activation process are discussed. This new SPE with outstanding electrochemical performance is a promising solid electrolyte candidate for applications in all-solid-state lithium battery.