Superionic glasses and glass-ceramics in the Li2S-P2S5 system for all-solid-state lithium secondary batteries

► The advantages and the development of Li2S-based superionic materials were reviewed. ► Superionic metastable phase were easily formed from Li2S-based glassy materials. ► The conductivity of 5 × 10− 3 Scm− 1 was attained by dopings and process optimization. ► The Li2S-based materials were suitable for all-solid-state lithium batteries.