LiTa2PO8-Based Polymer-Ceramic Electrolyte Paved the Way to High-Performance Solid-State Lithium Metal Batteries

Solid composite electrolytes, leveraging the advantages of both ceramics and polymers, are emerging as a viable alternative to liquid electrolytes in all-solid-state lithium metal batteries. Here, we have developed a polymer-ceramic composite electrolyte with an area-specific resistance of similar to 94 Omega cm(2) at room temperature (RT) by the solution casting method. A Li-ion conducting LiTa2PO8 ceramic with an RT bulk conductivity of similar to 3.2 x 10(-4) S cm(-1) was synthesized to act as an active filler in a PEO/PVDF-HFP polymer matrix complexed with LiTFSI salt to obtain a polymer-ceramic composite electrolyte. The symmetric lithium cell with the optimized electrolyte exhibited excellent cyclability over 950 cycles at an areal current density of 0.2 mA cm(-2). The full cell with LiFePO4 cathode and lithium metal anode delivered a specific capacity of similar to 115 mAh g(-1) with similar to 85% capacity retention after 500 cycles at 1C at RT, making it a viable alternative to be adopted in Li-ion batteries for room temperature applications.