Atomically dispersed Mn, N doped the cotton biomass aerogel of carbon fibers as bifunctional oxygen electrocatalyst for long-term rechargeable Zn-air battery

The great attention of rechargeable Zn-air battery has motivated extensive research on the development of inexpensive, highly efficient, and robust noble-metal-free bifunctional catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). In this work, Mn-N-C-950 single-atom catalyst with biomass aerogel as precursor was successfully synthesized. The resulting Mn-N-C-950 exhibited excellent bifunctional catalytic performance for ORR ( E 1/2 = 0.843 V) and OER ( E j=10  = 1.56 V) in alkaline electrolytes, which can compete with previously reported bifunctional electrocatalysts. In addition, compared to the Pt/C + RuO 2 mixed catalyst, this bifunctional catalyst can endow the self-made zinc-air battery with better power density (114.1 mW/cm 2 ) and cycle stability (105.5 h), demonstrating its potential feasibility in practical applications of rechargeable metal air batteries.