Oxide‐Based Pseudo‐Solid‐State Hybrid Electrolyte Functionalized by Ionic Liquid for Lithium Metal Batteries

Solid‐state batteries draw attention as next‐generation batteries that can provide higher energy density and overall stability based on the inherent nonflammability of the solid electrolytes. However, solid electrolytes have a clear limitation of low ionic conductivity due to their high resistance at grain boundaries and interfaces. Herein, oxide‐type solid electrolytes and ionic liquid electrolytes are introduced to reduce the overall resistance and form a clay‐textured composite electrolyte after a hybrid process. This composite electrolyte exhibits a stable state without side reactions and 1.6 ms cm −1 of improved ionic conductivity. This material also demonstrates its high thermal and electrochemical stability by high‐temperature exposure test and the application of bipolar configuration in conventional coin cells with high voltage. Therefore, this original clay‐textured pseudo‐solid‐state hybrid electrolyte is believed to contribute to the studies related to oxide‐type solid electrolytes for advanced solid‐state batteries.