Enhanced Thermal Stability and Electrochemical Performance of ZIF-8-Filled Polyacrylonitrile/Biobased Polyurethane Nanofibrous Membranes as Durable Separators for Aqueous Zinc-Ion Batteries

Separators are essential components in batteries, providing crucial reproducibility and processability for energy storage applications. However, conventional separators often struggle with low thermal stability and poor electrochemical properties, which can significantly affect their performance in aqueous zinc-ion batteries (AZIBs). To address these issues, polyacrylonitrile/polyurethane (PAN/PU) nanofibrous membranes were developed through electrospinning, further incorporating the zeolitic imidazolate framework-8 (ZIF-8) to enhance their overall performance. The integration of ZIF-8 decreased thermal shrinkage, increased flame retardancy of the membranes, and also increased the lifespan and long-term stability under operational conditions. At 10%ZIF-8, the electrolyte uptake and ionic conductivity were enhanced by up to 2623% and 5.88 × 10^-3 S cm^-1, indicating excellent electrolyte compatibility and ion transport efficiency. Furthermore, this membrane showed stable charge/discharge cycling over 1000 h. These enhancements suggested that the ZIF-8/PAN/PU nanofibrous membranes provided a durable and efficient separator solution for AZIBs, effectively addressing the challenges of conventional separators in aqueous systems. Hence, this membrane offers a promising choice of separators with high thermal stability and enhanced electrochemical performance for long-term AZIB applications.