Formation of core-shell structure MnCo2O4 microspheres and as a bifunctional catalyst for zinc-air batteries

Abstract

Efficient and stable bifunctional catalysts, facilitating oxygen reduction and oxygen evolution, play a pivotal role in energy conversion and storage fields. In this paper, four core-shell MnCo2O4 catalyst samples are prepared by controlling different solvent heating time, which are 0.5 h, 2 h, 6 h, and 12 h, respectively. The subsequent tests indicate that the sample with a 6 h not only has an ideal core-shell structure, but also exhibits favorable performance. The unique core-shell structure and favorable electrochemical performance are mainly attributed to the prepared precursor spheres. The microspheres have an inherent core-shell structure. Detailed studies of the morphological variations of MnCo2O4 catalysts with the different solvent heating time are performed using transmission electron microscopy and field emission scanning electron microscopy. Furthermore, we analyze the potential formation mechanism of the core-shell structure MnCo2O4 catalyst. The obtained core-shell structured MnCo2O4 catalysts provide a new way for the preparation of cathode catalyst for zinc-air batteries.