In Situ Forming LiF Nano-Decorated Electrolyte/Electrode Interfaces for Stable All-Solid-State Batteries

Abstract The unstable solid electrolyte/electrode interface with dendrite growth and resistance increase significantly reduces the safety and efficiency of all-solid-state batteries. Here, we propose an “in-situ LiF nano-decoration” approach to address this issue. By uniform dispersion of ultrafine LiF nanoparticles in amorphous Li2B12H12 matrix that is in-situ formed via a solid-state reaction, the resulting composite as electrolyte exhibits favorable Li-ion conductivity (5×10-4 S cm-1) with low electronic conductivity (9×10-10 S cm-1) at 75 °C. More importantly, this composite electrolyte shows superior electrode compatibility by forming stable electrolyte/electrode interfaces, as demonstrated by high Li dendrite suppression capability (critical current density: 3.6 mA cm-2) and small interfacial resistance (area specific resistance after 10 cycles: 746 Ω cm2) at 75 °C, which further enables the stable cycling of Li-LiFePO4 all-solid-state batteries. This work paves a way for employing in-situ nano-decoration chemistry for the design of safe and high efficiency all-solid-state batteries.