Bio-inspired rigid-soft coupling gel polymer electrolyte for stable lithium batteries

Gel polymer electrolytes (GPEs) are increasingly recognized for their potential to enhance lithium (Li)-ion batteries owing to their exceptional thermal stability and remarkable electrochemical performance. Despite these advantages, the practical application of traditional GPEs is hindered by their tendency to swell and their limited mechanical strength. To address these issues, this study introduces a bio-inspired rigid-soft coupling GPE comprising polyethylene oxide (PEO) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), reinforced with Kevlar fiber fabric fabricated using a simple solution-casting method. The resulting PEO/PVDF-HFP/Kevlar (PPK) GPE demonstrates excellent ionic conductivity of 2.815 mS cm⁻¹ and a Li-ion migration number of 0.571, alongside an ultra-high mechanical strength of 32.59 MPa. These features collectively contribute to the prevention of lithium dendrite growth and enhanced electrochemical performance of LiFePO₄ cells, leading to stable cycling performance. The deployment of PPK GPE can pave the way for significant advancements in high-performance Li-ion batteries for various practical applications.