Tuning the Properties of Halide Nanocomposite Solid Electrolytes with Diverse Oxides for All-Solid-State Batteries.

Herein, we report halide nanocomposite solid electrolytes (HNSEs) that integrate diverse oxides with alterations that allow tuning of their ionic conductivity, (electro)chemical stability, and specific density. A two-step mechanochemical process enabled the synthesis of multimetal (or nonmetal) HNSEs, MO 2 -2Li 2 ZrCl 6 , as verified by pair distribution function and X-ray diffraction analyses. The multimetal (or nonmetal) HNSE strategy increases the ionic conductivity of Li 2 ZrCl 6 from 0.40 to 0.82 mS cm -1 . Additionally, cyclic voltammetry test findings corroborated the enhanced passivating properties of the HNSEs. Notably, incorporating SiO 2 into HNSEs leads to a substantial reduction in the specific density of HNSEs, demonstrating their strong potential for achieving a high energy density and lowering costs. Fluorinated SiO 2 -2Li 2 ZrCl 5 F HNSEs exhibited enhanced interfacial compatibility with Li 6 PS 5 Cl and LiCoO 2 electrodes. Cells employing SiO 2 -2Li 2 ZrCl 5 F with LiCoO 2 exhibit superior electrochemical performance delivering the initial discharge capacity of 162 mA h g -1 with 93.7% capacity retention at the 100th cycle at 60 °C.