Synthesis of poly(ethylene-oxide)/nanoclay solid polymer electrolyte for all solid-state lithium/sulfur battery

A solid polymer electrolyte is fabricated using polyethylene oxide (PEO), lithium bis(Trifluromethanesulfonyl)imide (LiTFSI), and montmorillonite (MMT), with the aim of improving lithium ion conductivity, and the resulting solid polymer electrolyte is used for all solid-state lithium/sulfur batteries. The effect of temperature and nanoclay content on the conductivity of the resulting solid polymer electrolyte is investigated. The optimized electrolyte containing 10 wt% MMT exhibits ionic conductivity of 3.22 × 10−4 S cm−1 at 60 °C, a value that meets the operation requirements of an all solid-state sulfur cell. At 60 °C, all solid-state Li/S batteries using PEO/MMT solid polymer electrolyte display a good cycling performance, delivering 998 mAh g−1 initial discharge capacities and retaining a reversible specific discharge capacity of 634 mAh g−1 after 100 cycles at 0.1 C rate. At a higher rate of 0.5 C, the solid-state batteries still could deliver an acceptable specific discharge capacity of 643 mAh g−1 at 60 °C.