Effect of metal cations on the conductivity and interfacial stability of Li7P3S10.7Br0.3 sulfide solid-state electrolytes

The development of sulfide solid electrolyte is limited by the interface instability with lithium metal and low ionic conductivity. In this work, the effects of doping SiS2, SnS, ZnS and MnS on the ionic conductivity and interfacial stability of sulfide electrolytes are systematically investigated. The conductivity of Li7P2.9Sn0.1S10.7Br0.3 solid electrolyte was as high as 1.67 mS cm-1 . Furthermore, it is found that the critical current density was proportional to the resistivity of the doping element. The critical current density of the electrolyte was significantly increased by electronically insulating Si doping, reaching 0.858 mA cm-2 .