Preparation and performance study of a PVDF–LATP ceramic composite polymer electrolyte membrane for solid-state batteries

Abstract

Recently, safety issues in conventional organic liquid electrolytes and the interface resistance between the electrode and electrolyte have been the most challenging barriers for the expansion of lithium batteries to a wide range of applications. Here, an ion-conductive PVDF-based composite polymer electrolyte (CPE) consisting of lithium aluminum germanium phosphate (Li_1.3Al_0.3Ti_1.7(PO₄)₃) and polyvinylidene fluoride (PVDF) is prepared on a Li metal anode via a facile casting method. The ionic conductivity and electrochemical stability were enhanced by incorporating an appropriate amount of LATP into the PVDF-based composite polymer electrolyte, and the optimum content of LATP in the hybrid solid electrolyte was approximately 90 wt%. The corresponding solid-state battery based on an SEI-protected Li anode, the PVDF–LATP electrolyte, and a LiMn₂O₄ (LMO) cathode exhibited excellent rate capability and long-term cycling performance, with an initial discharge capacity of 107.4 mA h g⁻¹ and a retention of 91.4% after 200 cycles.