Low-cost, dendrite-blocking polymer-Sb2O3 separators for lithium and sodium batteries

We describe here preparation and performance of an ultra-flexible and low-cost Sb2O3/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/AClO₄ (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 Sb2O3.