Nonsolvent-Induced\nPhase Separation pPAN Separators\nfor Dendrite-Free Rechargeable Aluminum Batteries

Rechargeable\naluminum batteries (RAB) are a promising\nenergy storage\nsystem with high safety, long cycle life, and low cost. However, the\nstrong corrosiveness of chloroaluminate ionic liquid electrolytes\n(ILEs) severely limits the development of RAB separators. Herein,\na nonsolvent-induced phase separation strategy was applied to fabricate\nthe pPAN (poly(vinyl alcohol)-modified polyacrylonitrile) separator,\nwhich exhibits prominent chemical and electrochemical stability in\nILEs. The pPAN separator, owing to its uniform pore size distribution\nand strong electronegativity with a zeta potential of about −10.20\nmV, can effectively inhibit the growth of dendrites. Benefiting from\nthe good ion conductivity (6.38 mS cm<sup>–1</sup>) and high\nion migration number (0.133) of pPAN separator, the full cell with\npPAN separator demonstrates stable operation for more than 500 cycles\nat 600 mA g<sup>–1</sup>, with a high capacity of 88.8 mAh\ng<sup>–1</sup>. When integrating into sodium-ion batteries,\nthe pPAN separators also show an excellent electrochemical performance.\nThis work provides a considerable approach for designing separators\nto address the issue of Al anode dendrite growth in RABs.