Performance Enhancement of HDPE‐Al ₂ O ₃ Nanowire Composite Separator Using Boehmite Coating and Electron Irradiation

Separators play a critical role in ensuring the performance and, most importantly, the safety of Li‐ion batteries (LIBs). Herein, a novel HDPE‐based separator with exceptional performance and safety features is developed through a comprehensive and multifaceted method, including Al 2 O 3 nanowires as reinforcing filler to enhance mechanical strength, boehmite (AlOOH) nanoparticle coating to improve dimensional stability, and electron irradiation to enhance the binding efficiency of PVDF binder through crosslinking. The resultant separator has mechanical strength 2.57 times that of a bare HDPE separator and thermal shrinkage of only 3.22% in contrast to 90% for bare HDPE at 150°C. The ionic conductivity and battery performance, including rate capability and cycling performance, underscore the superiority of the resultant separator over the bare HDPE separator. This innovative approach provides a promising pathway for developing high‐performance separators, addressing critical challenges in advanced LIB applications.