Synergistic Regulation of Zn and F in Li₆PS₅Cl for Enhancing Interface Stability and Suppressing Lithium Dendrites in All-Solid-State Lithium Batteries

Sulfide electrolytes with high ionic conductivity show great potential toward all-solid-state battery applications. However, interfacial instability between the sulfide electrolytes and lithium metal can lead to parasitic reactions and dendrite growth, resulting in a rapid degradation of battery performance. Herein, we propose a strategy to modify Li6PS5Cl (LPSC) solid electrolyte via codoping of Zn and F to address the interfacial parasitic reactions, as well as the dendrite growth issue. Zn atoms incorporated into LPSC can regulate the local electron density distribution, suppressing the irreversible redox interfacial parasitic reactions. F doping in situ generates a dense and uniform LiF interfacial layer, effectively inhibiting dendrite penetration. As a result, the modified electrolyte presents a high critical current density of up to 1.6 mA cm–2 and can achieve over 540 h stable plating/stripping at a current density of 0.1 mA cm–2. The assembled all-solid-state batteries also show outstanding cycling stability and rate performance compared with the original LPSC. This study emphasizes the importance of local electronic structure regulation in the modification of sulfide electrolytes, providing a highly promising strategy for achieving interface stability and dendrite-free all-solid-state lithium batteries.