High lithium ion conduction of sulfide glass-based solid electrolytes and their application to all-solid-state batteries

Abstract

Sulfide glass-based solid electrolytes prepared by melt quenching and mechanical milling were reviewed. The sulfide and oxysulfide glass–ceramic electrolytes in the system Li 2S–P 2S 5–P 2O 5 with superionic Li 7P 3S 11 and Li 3.25P 0.95S 4 crystals exhibited high conductivity of over 10 −3 S cm −1 at room temperature and high electrochemical stability. Newly designed all-sulfide batteries 80SnS·20P 2S 5/80Li 2S·20P 2S 5/75Li 2S·25Cu were successfully fabricated; reversible charge–discharge capacities of more than 400 mAh g −1 were observed after the second to 10th cycles. The operation of those all-sulfide lithium secondary batteries is a first step for the realization of the all-solid-state monolithic batteries.