Highly lithium-ion conductive thio-LISICON thin film processed by low-temperature solution method

► A low-temperature solution process has been developed to deposit Li3.25Ge0.25P0.75S4 thin film. ► The Li3.25Ge0.25P0.75S4 thin film has a lithium-ion conductivity of 1.82 × 10−4 S cm−1 at 30 °C. ► The Li3.25Ge0.25P0.75S4 thin film has a lithium-ion transference number of >0.999.