Wet-chemical synthesis of Li7P3S11 with tailored particle size for solid state electrolytes

Abstract The small-size solid-state electrolytes with high Li+ conductivity play an important role in reducing the interfacial resistance between electrode materials and solid state electrolytes. As one of the most conductive sulfide based ionic conductors, Li7P3S11 with scalable synthesis method and controllable particle sizes is highly desired but rarely reported. Here, we report a facile wet-chemical synthesis method to prepare Li7P3S11 solid state electrolytes with variable sizes for all-solid-state lithium batteries. By fully dissolving 70Li2S-30P2S5 precursors in ethyl acetate solution, the particle size of Li7P3S11 can be manipulated into as small as ∼ 110 nm and a highest Li+ conductivity of 1.05 mS cm−1 can be achieved. A systematical mechanistic study of solvent effects suggests that the controlled particle sizes are attributed to the excellent solvability and low binding energy of ethyl acetate solvent toward solutes. Moreover, this generic method can be extended to the facile synthesis of Li3PS4 nanoparticles with an average size of ∼ 200 nm and high Li+ conductivity of 0.1 mS cm−1.