A novel efficient electrocatalyst for oxygen reduction and oxygen evolution reaction in Li-O2 batteries: Co/CoSe embedded N, Se co-doped carbon

The research of highly efficient and large-capacity energy storage systems is the focus of the research community and the market. Lithium-oxygen (Li-O-2) batteries have shown great potential as next generation secondary batteries since their energy density is comparable to that of gasoline. Herein, we report a three dimensional (3D) self-supporting Co-CoSe@NSeC/bioC cathode fabricated through growing cobalt based metal organic framework (ZIF-67) on biomass and subsequent high-temperature selenization. The as synthesized Co-CoSe@NSeC/bioC cathode, benefiting from the 3D porous structure, the active defects derived from the doping of N, Se heteroatoms in carbon skeleton, and the highly-active of Co/CoSe heterojunction, shows excellent oxygen reduction reaction/oxygen evolution reaction (ORR/OER) electrocatalytic activity. It delivers a high specific capacity of 9.1 mAhmiddotcm(-2) at a current density of 0.05 mAmiddotcm(-2) and maintains 78 stable cycles. The good performance of Co-CoSe@NSeC/bioC proves its potential as cathode for Li-O-2 batteries.

Automated summary

This study reports a three-dimensional self-supporting Co-CoSe@NSeC/bioC cathode prepared by high-temperature selenization on biomass. The cathode exhibits excellent electrocatalytic activity for oxygen reduction reaction and oxygen evolution reaction, as well as high specific capacity and stable cycling performance. Therefore, Co-CoSe@NSeC/bioC cathode holds great potential as a cathode material for Li-O-2 batteries.