The separator with excellent mechanical and thermal properties are highly required for lithium ion batteries (LIBs). Therefore, it is crucial to develop novel nanofibrous membranes with enhanced mechanical strength and thermal stability. In this work, the fluorinated polyimide (FPI) was synthesized and blended with polyvinylidene fluoride (PVDF) to fabricate composite nanofibrous membranes (CNMs) via electrospinning method. Benefiting from the introduction of aromatic FPI, the prepared PVDF/FPI nanofibrous membranes were endowed with enhanced mechanical strength and thermal stability. When the FPI content increased from 0 to 30 wt%, the tensile strength of composite nanofibrous membranes enhanced from 1.57 to 2.30 MPa. Moreover, there are almost no dimensional shrinkage for the CNM-30 containing 30 wt% FPI after heat treatment at 160 °C for 1 h. Furthermore, the prepared CNMs show improved electrochemical performances in comparison with neat PVDF and commercial Celgard membranes. The electrolyte uptake and ionic conductivity of the CNMs could reach to 522.4% and 1.14 ms·cm⁻¹, respectively. The prepared CNMs could provide an innovative and promising approach for the development and design of high-performance separators.

锂离子电池（LIB）非常需要具有优异机械和热性能的隔膜。因此，开发具有增强机械强度和热稳定性的新型纳米纤维膜至关重要。在这项工作中，氟化聚酰亚胺（FPI）被合成并与聚偏二氟乙烯（PVDF）共混，通过静电纺丝方法制造复合纳米纤维膜（CNM）。得益于芳香族 FPI 的引入，制备的 PVDF/FPI 纳米纤维膜具有增强的机械强度和热稳定性。当FPI含量从0增加到30 wt%时，复合纳米纤维膜的拉伸强度从1.57 MPa提高到2.30 MPa。此外，在 160 °C 下热处理 1 小时后，含有 30 wt% FPI 的 CNM-30 几乎没有尺寸收缩。此外，与纯 PVDF 和商业 Celgard 膜相比，制备的 CNM 显示出改进的电化学性能。CNMs的电解质吸收和离子电导率可达522.4%和1.14 ms·cm^-1，分别。制备的 CNM 可为高性能隔膜的开发和设计提供一种创新且有前景的方法。