Melamine-assisted pyrolytic synthesis of bifunctional cobalt-based core–shell electrocatalysts for rechargeable zinc–air batteries

Abstract Designing a highly activity and stability non-noble metal bifunctional oxygen catalyst for rechargeable Zn-air battery remains a great challenge. Herein, we develop a facile and melamine-assisted-pyrolysis (MAP) strategy for the synthesis of core-shell Co-based electrocatalysts@N-doped carbon nanotubes (Co@CNTs) derived from metal–organic frameworks. The Co@CNTs exhibited excellent bifunctional electrocatalytic performance for both oxygen evolution and reduction. DFT calculations demonstrated that the Gibbs free energy of the rate-determining step was small enough to improve ORR activities. As a result, a Zn-air battery assembled with Co@CNTs proves a lager power density, low voltage gap between charge–discharge and excellent stability. Thus, this work offers a facile strategy to realize the synthesis of non-noble metal electrocatalyst for Zn-air battery materials with high electrochemical performance.