Low-Cost, Dendrite-Blocking Polymer-Sb₂O₃Separators for Lithium and Sodium Batteries

We describe here preparation and performance of an ultra-flexible and low-cost Sb 2 O 3 /polymer composite membrane separator for Na-ion or Li-ion batteries operating with metallic Na or Li anodes. The separator has a large electrolyte window, excellent thermal and mechanical stabilities when infused with EC/DEC/AClO 4 (1M) electrolyte (A = Li or Na), excellent wettability and acceptable ionic conductivity to 1C rate. The ability of the separator to block anode dendrites from crossing it is demonstrated in symmetric alkali-metal cells and in the performances of Na-ion and Li-ion cells with/without loading with Sb 2 O 3 .