MOF-derived Co3O4 nanoparticles embedded in NiO nanosheet arrays as heterostructure cathode for rechargeable lithium-oxygen batteries

Catalysts with high stability and efficient electrocatalytic properties are urgently explored to improve sluggish kinetics of the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in Li-O-2 batteries. In this paper, exquisitely designed bifunctional catalyst comprising Co3O4 nanospheres embedded in NiO nanosheet arrays on carbon cloth as a freestanding cathode is reported. The unique hierarchical structure facilitates the continuous oxygen diffusion and the transport of Li+. Moreover, benefitting from the synergetic effect between NiO and Co3O4, the interface charge transfer kinetics was greatly enhanced. As a result, Li-O-2 cells based on the integrated NiO/Co3O4/CC electrode present an improved overpotential of 1.1 V, a high discharge capacity of 8000 mAh g(-1) at 200 mA g(-1) and an enhanced cycle stability of 130 cycles under a restricted capacity at 500 mAh g(-1) were reached.

Automated summary

A bifunctional catalyst composed of Co3O4 nanospheres embedded in NiO nanosheet arrays on carbon cloth was reported, showing enhanced charge transfer kinetics and improved oxygen and Li+ transport. This catalyst led to Li-O-2 cells with significantly decreased overpotential and enhanced cycle stability.