Preparation of Li2S–GeS2 solid electrolyte thin films using pulsed laser deposition

Amorphous Li2S–GeS2 solid electrolyte thin films were prepared using pulsed laser deposition (PLD) at the compositions of 67–83 mol% Li2S. The ionic conductivities at room temperature increased with increasing Li2S contents and attained a maximum value of 1.8 × 10− 4 S cm− 1 at the composition of 78 mol% Li2S. The obtained solid electrolyte thin film was applied to form an ideal electrode–electrolyte interface in all-solid-state batteries. The all-solid-state lithium cell using LiCoO2 coated with the solid electrolyte thin film operated as a lithium secondary battery at room temperature.

► Li2S–GeS2 solid electrolyte (SE) thin films were synthesized by PLD. ► Amorphous Li2S–GeS2 thin films showed high ionic conductivity of 10− 4 S cm− 1. ► LiCoO2 particles coated with SE thin films were prepared by PLD. ► All-solid-state cells with SE-coated LiCoO2 particles operated at 25 °C.