Dual-metal M-N-C (M = Mn, Co) as an effective oxygen electrocatalyst for zinc-air battery

Developing high-active and low-cost non-noble metal electrocatalysts is an efficient strategy for design of advanced rechargeable Zn-air battery (ZAB). Herein, an oxygen electrocatalyst of Prussian-blue-analogues derived MnCo dual-metal M-N-C (PBA-MnCo-N-C) is prepared using a carbonization method. The electrochemical tests show that, it owns good oxygen reduction reaction (ORR) performances with the onset potential of 0.966 V and half-wave potential of 0.859 V, almost approaching that of Pt/C catalysts. Simultaneously, a good oxygen evolution reaction (OER) activity is also obtained, with a potential of 1.844 V at 10 mA cm⁻². In the practical application, as-assembled ZAB with PBA-MnCo-N-C exhibits high open circuit potential (1.48 V) and peak power density (102.25 mW cm⁻²), and after continuous discharge and charge for more than 160 h, the PBA-MnCo-N-C based ZAB manifests a favorable charge-discharge stability. This work provides a good reference of constructing bimetallic catalyst for high-efficiency oxygen electrocatalysis.