Mass-ratio-regulated Co3O4/α-MnO2/C heterostructured catalyst for ORR in Zn–air batteries

Developing low-cost, high-performing non-noble-metal catalysts for the oxygen reduction reaction (ORR) to replace Pt-based catalysts for practical metal-air batteries remains an enormous challenge. Herein, Co 3 O 4 /α-MnO 2 /C composite catalysts with different mass ratios are synthesized, and a heterostructured Co 3 O 4 /α-MnO 2 /C catalyst is successfully constructed. Benefiting from the synergistic interaction between Co 3 O 4 and α-MnO 2 , together with the enhanced conductivity imparted by the carbon support, the catalyst exhibits outstanding electrocatalytic activity. Furthermore, derivative analysis of the LSV curves is employed to accurately determine the ORR onset potential and half-wave potential, providing a quantitative approach for evaluating the electrochemical activity of the Co 3 O 4 /α-MnO 2 /C catalyst. Furthermore, a Zn-air battery driven by the Co 3 O 4 /α-MnO 2 /C catalyst shows excellent electrochemical performance, delivering a high open-circuit voltage of 1.458 V and long-term cycling stability for 300 h. Notably, its overall performance is close to that of commercial Pt/C catalysts. This work highlights the considerable promise of non-noble-metal catalysts for renewable energy storage and conversion applications.