Self-Vulcanized Heterogeneous Interface Derived from Organic Cobalt Residue for Rechargeable Zinc-Air Batteries

The expedited synthesis of advanced bifunctional catalysts from waste resources is promising for improving the application of Zn-air batteries (ZAB). In this study, a self-vulcanization strategy was developed to directly transform industrial organic cobalt dimethyldithiocarbamate (CDC) residue into bifunctional oxygen electrocatalysts with an N,S-codoped carbon skeleton and a Co1-xS/Co9S8 heterogeneous interface. The catalytic activity of the CDC-derived catalysts depended on the self-vulcanization temperature. CDC-800 exhibited bifunctional catalytic activity for oxygen evolution (eta = 371 mV at 10 mA cm(-2)) and oxygen reduction (E-1/2 = 0.76 V) reactions. The assembled rechargeable ZAB with a CDC-800 air cathode exhibited an excellent peak power density (75.2 mW cm(-2)), specific capacity (873 mA h g(Zn)(-1)), and cycle stability (over 670 h), respectively. This superior catalytic performance mainly resulted from the self-vulcanized Co1-xS/Co9S8 heterogeneous interface. Therefore, direct self-vulcanization of organic cobalt residues can contribute to the reduction of the pollution caused by hazardous wastes and sustainable preparation of high-performance bifunctional catalysts.