Interface design strategy in combined materials of lithium thiophosphate electrolyte for solid-state lithium-ion batteries applications

•Li7P3S11 is synthesized by a facile ball-milling followed a vacuum sintering technique.•The phase purity of the sulfide is optimized by controlling the ball-milling time and subsequent sintering temperature.•Ball-milling for 4 h and sintering at 250 °C yieled the highest sample ionic conductivity 1.14 × 10−3 Scm−1 among those tested materials.•Li stripping/plating performance is evaluated by different sizes of Li-electrodes and different types of solid-state cell design.