Our group develops new inorganic lithium/sodium-ion conducting solid electrolytes (SEs) for all-solid-state batteries (ASBs). Low ionic conductivity of
SEs is a bottleneck for commercialization of ASBs. Aliovalent substitution offers increased ionic conductivity by diverse factors, such as creating
lithium/sodium vacancy and expansion of lithium/sodium conducting channels. Limited chemical stability is a critical shortcoming of sulfide SEs. When
sulfide SEs are decomposed upon exposure to humid air, H2S gases are evolved. Our group has been developing new air-stable SEs and surface
modification of SEs.
For the preparation of sulfide SEs, conventional synthesis protocols for ceramic materials, such as high-temperature solid-state reaction, have been
widely used. Recently, alternative protocols using liquid solvents have been in the spotlight due to potential advantages, such as mass production,
modification of size and morphology of SEs, and possibility to obtain new metastable materials.