Poly(ether ketone nitrile)/Poly(vinylidene fluoride) Separators Reinforced by Li6.5La3Zr1.5Ta0.5O12 for Enhanced Thermal Stability and Safety in Lithium-Ion Batteries

Abstract

Lithium-ion batteries (LiBs) are becoming more widely utilized for storing clean energy, but the safety and cycle life remain major concerns. This study focuses on developing porous composite films made from poly(ether ketone nitrile) (PENK) and poly(vinylidene fluoride) (PVDF), enhanced with Li_6.5La₃Zr_1.5Ta_0.5O₁₂(LLZTO) filler. These films were fabricated using the non-solvent-induced phase separation (NIPS) method to address the insufficient thermal resilience and the inadequate electrolyte wettability of conventional polyolefin separators. The impact of LLZTO content levels on the film’s composition, heat resistance, mechanical characteristics, and electrochemical behavior were systematically assessed. The findings show that incorporating LLZTO significantly improves electrolyte wettability, thermal stability, and cycling performance. Additionally, LLZTO efficiently suppresses lithium dendrite formation, thereby improving battery safety and overall performance. The optimized PENK/PVDF composite films demonstrated superior thermal stability and maintained a high capacity over extended cycles, this makes it a highly promising option for the development of high-performance lithium-ion batteries.