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

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 MnCo 2 O 4 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 MnCo 2 O 4 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 MnCo 2 O 4 catalyst. The obtained core-shell structured MnCo 2 O 4 catalysts provide a new way for the preparation of cathode catalyst for zinc-air batteries. • The precursor spheres produced had an inherent core-shell structure. • Effect of precursor structure on the performance of MnCo 2 O 4 after calcination. • The formation mechanism of the core-shell structure MnCo 2 O 4 catalyst. • MnCo 2 O 4 provides a fast kinetic for electrons and reaction intermediates. • Core-shell MnCo 2 O 4 has the potential to replace noble metal catalysts. [ABSTRACT FROM AUTHOR]