High-Performance Solid-State Li-ion Batteries Enabled by Homogeneous, Large-Area Ferroelectric PVDF-TrFE Solid Polymer Electrolytes via Horizontal Centrifugal Casting Method

Abstract

Solid polymer electrolytes (SPEs) have become attractive options for improving the safety aspects of lithium- ion batteries (LIBs) while maintaining compatibility with current LIB production methods. Nevertheless, a consistent issue has been the relatively low output obtained through conventional fabrication methods like solution casting and doctor blade techniques. In this research, we introduce an innovative method to create large and uniform SPE films using the ferroelectric polymer polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE). This technique utilizes horizontal centrifugal casting (HCC), which has not been previously applied to SPE production. The significant centrifugal forces produced during the HCC process result in SPE films with even thickness throughout and high ionic conductivity at room temperature. When compared to traditional solution casting methods, the Li//Li cell containing the SPE produced by HCC exhibits stable electrochemical performance and extended cycle life. Moreover, a complete cell with a Li iron phosphate cathode shows steady electrochemical performance at room temperature. Remarkably, a 3 × 4 cm² pouch cell retains its performance characteristics even under physical stress like folding and puncturing. These results highlight the potential efficacy of using the HCC method for developing high-performance SPE-based LIB systems.