Crystalline Li7P3S11 is a promising solid electrolyte for all solid state lithium/lithium ion batteries. A controllable liquid phase synthesis of Li7P3S11 is more desirable compared to conventional mechanochemical synthesis, but recent attempts suffer from reduced ionic conductivities. Here we elucidate the formation mechanism of crystalline Li7P3S11 synthesized in the liquid phase (acetonitrile, or ACN). We conclude that the crystalline Li7P3S11 forms through a two-step reaction: 1) formation of solid Li3PS4·ACN and amorphous Li2S·P2S5 phases in the liquid phase; 2) solid-state conversion of the two phases. The implication of this two-step reaction mechanism to the morphology control and the transport properties of liquid phase synthesized Li7P3S11 is identified and discussed.
Revised: November 9, 2020 |
Published: February 13, 2018
Citation
Wang Y., D. Lu, M.E. Bowden, P.Z. El-Khoury, K. Han, Z. Deng, and J. Xiao, et al. 2018.Mechanism of Formation of Li7P3S11 Solid Electrolytes through Liquid Phase Synthesis.Chemistry of Materials 30, no. 3:990-997.PNNL-SA-130713.doi:10.1021/acs.chemmater.7b04842