刚柔并济的仿生凝胶聚合物电解质助力稳定的锂电池

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

凝胶聚合物电解质(GPE)因其优良的热稳定性和卓越的电化学性能而具备增强锂离子电池性能的潜力,从而受到越来越多的认可.尽管其具有上述优点,但传统GPE的实际应用通常因其溶胀性和有限的机械强度而受到阻碍.为了解决这些问题,本项研究工作提出了一种通过简单方法构建的刚柔并济的仿生GPE,由聚环氧乙烷(PEO)和聚偏二氟乙烯-六氟丙烯(PVDF-HFP)组成并通过Kevlar纤维织物进行增强.所得的PEO/PVDF-HFP/Kevlar(PPK)GPE表现出2.815 mS cm^(−1)的优异离子电导率和0.571的锂离子迁移数,以及32.59 MPa的超高机械强度.这些特性有助于防止锂枝晶生长并增强LiFePO4电池的电化学性能,从而实现稳定的循环性能.PPK GPE可以为高性能锂离子电池的各种实际应用提供理论基础.

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-cohexafluoropropylene)(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 Liion 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 highperformance Li-ion batteries for various practical applications.