A Co-MOF decorated gel separator with high safety and stable electrochemical performance for lithium-sulfurized poly(acrylonitrile) batteries

In this work, a high-temperature-tolerant poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP)-based gel polymer electrolyte (GPE) separator was fabricated for lithium-sulfurized poly(acrylonitrile) (Li-SPAN) batteries through a one-step electrospinning process. The ZIF-67/PMIA@PVDF-HFP (MOF-PPH) separator, enhanced by the synergistic effects of ZIF-67 and poly( m -phenylene isophthalamide) (PMIA), exhibited remarkable thermal stability, maintaining dimensional integrity at 200 °C, robust tensile strength (14.96 MPa), and superior electrolyte absorption (704 %). In addition, abundantly dispersed ZIF-67 nanoparticles, characterized by a uniform microporous size and high specific surface area, facilitated the uniform deposition of Li + and effectively suppressed the disordered growth of lithium dendrites. The Li-SPAN battery equipped with the MOF-PPH separator demonstrated significantly improved cycling stability, with a discharge capacity of 1406.1 mAh g −1 and a capacity retention rate of 95.6 % after 200 cycles at 0.2 C. Furthermore, the MOF-PPH separator showed steady cycling behavior, even under high sulfur loading, lean electrolyte, and elevated operating temperature conditions. This result highlights its potential for future energy storage systems that provide high safety and performance.