Solution‐Processed Synthesis of Nano‐Sized Argyrodite Solid Electrolytes with Cavitation Effect for High Performance All‐Solid‐State Lithium‐Ion Batteries

To mitigate poor contact issues between electrolyte/electrode materials interfaces of all‐solid‐state batteries (ASSB), we newly introduce a novel solution‐processed synthesis that exploits the differences in the boiling point and polarity of the two solvents (i. e., methanol, and toluene), with a cavitation effect by bubbling inert gas. Through this process, called solvent exchange with bubbles (SEB), the Li6PS5Cl solid electrolyte is synthesized with a particle size below 800 nm and sufficient ionic conductivity of 1.54 mS/cm at 25 °C. In addition, the ASSB cell consisting of the cathode electrode with Li6PS5Cl synthesized by the SEB exhibited a high capacity of 176 mAh/g at 0.1 C (55 °C) owing to the improved contact between the electrode and solid electrolyte. In particular, the rate capability of the cell is superior to that of a cell with Li6PS5Cl prepared by ball milling. Small particles larger contacts: Comparison of lithium‐ion conducting pathway at cathode electrode and charge‐discharge electrochemical performances of lithium half cell according to solid electrolyte synthesis process of ball milling (BM) and solvent exchange with bubbles (SEB).