Highly efficient nitrogen-doped three-dimensional interconnected porous carbon supported heterogeneous Co/MnO nanoparticles oxygen electrocatalysts for rechargeable zinc air batteries

Rechargeable zinc-air batteries (RZABs) show great promising in the current energy storage system because of their high energy density, low cost and high safety. However, RZABs’ cycling performance is still unsatisfactory due to the sluggish oxygen reduction and oxygen evolution reaction kinetics of air electrode. Transition Metal Oxides (TMOs) are considered to be highly promising oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalysts for RZABs by high activity, robust stability and low cost. Here, the nitrogen-doped three-dimensional interconnected porous carbon supported heterogeneous Co/MnO nanoparticles composite (Co/MnO-NCs) as the air cathode in RZAB is synthesized via annealing method. The NCs not only provide efficient electron transfer channels but also significantly increases the specific surface area of the catalyst, exposing more reaction sites. MnO can effectively facilitate charge transfer and accelerate the decomposition reactions. The heterogeneous Co/MnO interface provides efficient reaction sites for the ORR/OER. Electrochemical results show that the prepared Co/MnO-NCs composite not only exhibits excellent ORR/OER performance but also demonstrates good stability. Furthermore, RZABs assembled by Co/MnO-NCs air cathode exhibit high open circuit voltage, high specific capacity and durable cyclic stability. This strategy has broad versatility and can be generalized to other TMOs electrocatalysts for RZABs.