Abstract
Solid-state electrolytes with high ionic conductivities are crucial for the development of all-solid-state lithium batteries, and there is a strong correlation between the ionic conductivities and underlying lattice structures of solid-state electrolytes. Here, we report a lattice manipulation method of replacing [Li(2)OH](+) clusters with potassium ions in antiperovskite solid-state electrolyte (Li(2)OH)(0.99)K(0.01)Cl, which leads to a remarkable increase in ionic conductivity (4.5 × 10(‒3) mS cm(‒1), 25 °C). Mechanistic analysis indicates that the lattice manipulation method leads to the stabilization of the cubic phase and lattice contraction for the antiperovskite, and causes significant changes in Li-ion transport trajectories and migration barriers. Also, the Li||LiFePO(4) all-solid-state battery (excess Li and loading of 1.78 mg cm(‒2) for LiFePO(4)) employing (Li(2)OH)(0.99)K(0.01)Cl electrolyte delivers a specific capacity of 116.4 mAh g(‒1) at the 150th cycle with a capacity retention of 96.1% at 80 mA g(‒1) and 120 °C, which indicates potential application prospects of antiperovskite electrolyte in all-solid-state lithium batteries.