Recent progress on understanding and constructing reliable Na anode for aprotic Na-O2 batteries: A mini review

Aprotic Na-O-2 batteries attract increasing attention for the low charging/discharging overpotentials, high energy density, and low cost. Significant progress has been achieved in the battery system, but challenges remain in constructing reliable Na anodes. This review presents an overview of the fundamental understanding of Na anodes in aprotic Na-O-2 batteries, including chemical reactivity of Na metal and dendrite formation mechanism. The constructing strategies are summarized as mechanical reinforcement of separators, electrolyte modifications, and electrode structure and material design. Perspectives are envisioned for the further development of durable Na anodes for aprotic Na-O-2 batteries.