Novel fusiform core-shell-MOF derived intact metal@carbon composite: An efficient cathode catalyst for aqueous and solid-state Zn-air batteries

Owing to the varied mechanisms of ORR/OER, exploiting cost-effective bifunctional catalysts with robust ORR/OER activities and excellent performances in Zn-air batteries is still a challenge. In this work, the Co/CoO@NSC bifunctional catalyst is obtained by using Zn-MOF@Co-MOF as self-template. The Co/CoO@NSC composite has interconnected porous architecture with intact metal@carbon structure, exhibiting superior electrocatalytic activities toward ORR and OER that can be comparable with the Pt/C and RuO2 catalysts, respectively. The Co/CoO@NSC-based aqueous Zn-air battery achieves a high specific capacity (759.7 mAh/g) and energy density (990.5 Wh/kg), and ultra-long rechargeable property (more than 400 h/1200 cycles). The Co/CoO@NSC-based solid-state Zn-air battery also delivers an excellent performance with a long cycle life (more than 143 h/858 cycles). Most importantly, the newly synthesized and recharged Co/CoO@NSC-based solid-state Zn-air battery can be used to light up a 2 V LED lamp for more than 28 h, demonstrating the superior practicability as rechargeable power source. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

The Co/CoO@NSC bifunctional catalyst with interconnected porous architecture and intact metal@carbon structure shows superior electrocatalytic activities in ORR and OER comparable to Pt/C and RuO2 catalysts. The resulting Zn-air batteries exhibit high specific capacity, energy density, and long rechargeable properties, highlighting its potential as a rechargeable power source.