Free-Standing and Flexible Garnet-PVDF Ceramic Polymer Electrolyte Membranes for Solid-State Batteries

Abstract

Solid-state batteries have been getting considerable attention in recent times due to the safety issues associated with liquid electrolyte-based batteries. However, most rigid solid electrolytes are vulnerable to mechanical strains, so implementation in a commercial battery needs proper modifications. Polymer-type flexible membranes could overcome the size and fragility. Herein, we propose a straightforward preparation of flexible and thin ceramic polymer electrolyte membranes combined with the advantage of garnet-structured fast lithium-ion conductors (Li6.28Al0.24La3Zr2O12) with polyvinylidene fluoride polymers. An 8:2 ratio of garnet to polymer has been employed to create a free-standing flexible ceramic polymer electrolyte through tape casting. The membrane showed excellent electrochemical performance with good conductivity and thermal–electrochemical stability. A facile way of polymer electrolyte casting over lithium iron phosphate electrode material, which contains 5 wt % garnet material, has been adapted to enhance the electrode–electrolyte contact. The cell has offered significantly notable performance. This way, the benefit of solid-state electrolytes could extend to the large-scale production of solid-state batteries with extended safety.