《Tuning ionic conductivity to enable all-climate solid-state Li-S batteries with superior performances》

Low lithium ion mobility is one of the main obstacles to achieving the excellent electrochemical performance of Li₂S-based solid-state lithium-sulfur batteries. The low lithium ion conductivity is due to the inherent insulation of Li₂S and poor contact between the Li₂S / solid electrolyte interface. Therefore, we propose that there is a correlation between increasing the lithium ion conductivity of the cathode mixture and the electrochemical performance of Li₂S-based solid-state batteries. On the one hand, replacing Li₆PS₅Cl with Li_5.5PS_4.5Cl_1.5 solid electrolyte with excellent conductivity can increase the interfacial ion mobility and reduce the solid/solid resistance, thereby obtaining higher discharge capacity and better cycle performance. In addition, Li₂S size and LiI doping were reduced by high-energy ball milling to enhance its lithium-ion conductivity. The solid-state lithium-sulfur battery was constructed by optimizing the selection of 3Li₂S-LiI cathode active material and combining it with Li_5.5PS_4.5Cl_1.5 solid electrolyte, which showed excellent electrochemical performance in the range of 0-60 °C. Our findings in this work are helping to promote the development of Li₂S-based solid-state lithium-sulfur batteries.

Links：https://pubs.rsc.org/en/content/articlehtml/2022/ma/d1ma00987g