Anion-tethered interface engineering enabling dendrite-free lithium metal anodes

A functionalized fiber separator with an anion-sieving effect facilitates rapid Li+ transfer and guides ordered Li deposition. The in situ integration of metal organic frameworks (MOFs) with polyacrylonitrile (PAN) fibers effectively prevents MOF agglomeration, and reduces the high reactivity of -CN groups with Li anodes. Real-time visualization technology confirms uniform Li deposition behavior. The Li‖Li symmetric cell demonstrates exceptional plating-stripping reversibility at 10 mA cm-2. The Li‖LiNi0.8Co0.1Mn0.1O2 cell exhibits 17% higher capacity retention after 250 cycles than commercial polyolefin separator. This in situ chemical modification enables dendrite-free Li metal batteries through separator engineering.