(592c) Mg3N2 doped Li7P3S11 Solid Electrolytes with Improved Interphase Compatibility in All Solid-State Li-S Battery

Li₇P₃S₁₁ is considered as one of the most promising electrolyte materials in all-solid-state Li-S battery due to its high ionic conductivity (comparable with liquid electrolyte). However, the all-solid-state Li-S battery with Li₇P₃S₁₁ as solid electrolytes has serious interface impedance issues between electrolytes and electrode.[1] The reaction between lithium metal and Li₇P₃S₁₁ solid electrolyte would form a SEI layer, which could impede lithium ions transfer and transport during charging and discharging, leading to resistance increase and capacity fade. In this study, Li₇P₃S₁₁ solid electrolyte doping with Mg₃N₂ were synthesized in liquid phase for an all solid-state lithium sulfur battery.[2] The Mg₃N₂ decomposed into a mixed ion/electron conducting interlayer to form Li₃N and Mg metal (both are good electronic conductor), thus enhance the interfacial compatibility between Li₇P₃S₁₁ solid electrolyte and lithium metal. With Mg₃N₂ doped Li₇P₃S₁₁ as solid electrolytes, the all solid-state Li-S battery exhibits an improved electrochemical performance such as lower resistance, better cycling stability and higher specific capacity.

1. Xu, X., et al., Boron nitride doped Li7P3S11 solid electrolyte with improved interfacial compatibility and application in all-solid-state Li/S battery. Journal of Materials Science: Materials in Electronics, 2019.
2. Yan, M., et al., Stabilizing Polymer–Lithium Interface in a Rechargeable Solid Battery. Advanced Functional Materials, 2019. 30(6).