Co9S8 with core-shell structure supported S/N co-doped carbon nanosheets for effective bifunctional electrocatalysts for rechargeable Zn-air battery

Abstract

A new S/N-containing Co(II) complex was synthesized by hydrothermal synthesis, and a uniformly dispersed porous carbon was successfully synthesized by carbonized nanocomposites. The prepared catalyst-a exhibited excellent electrochemical performance being as air cathode in a constructed rechargeable Zn-air battery. After a long-term galvanostatic discharge–charge durability test at 5 mA cm−2 over 166 h, the potential difference between the discharge and charge processes was only 0.65 V and the corresponding voltaic efficiency was as high as 64.7%. The active sites such as the M−N,S/C groups, the metallic oxides, the N/S-dopant and the surfae and edge defects cooperatively improve the oxygen electrocatalysis.