Nitrogen and Sulfur Co-doped Graphene Supported Cobalt Sulfide Nanoparticles as an Efficient Air Cathode for Zinc-air Battery

•CoS2 nanoparticles supported on a nitrogen and sulfur co-doped graphene oxide is described.•Improved round trip efficiency was observed for CoS2(400)/N,S-GO.•CoS2(400)/N,S-GO possess improved durability with low over-potential.•CoS2(400)/N,S-GO is a promising air cathode for zinc-air battery.

ABSTRACTZinc-air battery is considered as one of the promising energy storage devices due to their low cost, eco-friendly and safe. Here, we present a simple approach to the preparation of cobalt sulfide nanoparticles supported on a nitrogen and sulfur co-doped graphene oxide surface. Cobalt sulfide nanoparticles dispersed on graphene oxide hybrid was successfully prepared by solid state thermolysis approach at 400 °C, using cobalt thiourea and graphene oxide. X-ray diffraction study revealed that hybrid electrode prepared at 400 °C results in pure CoS2 phase. The hybrid CoS2(400)/N,S-GO electrode exhibits low over-potential gap about 0.78 V vs. Zn after 70 cycles with remarkable and robust charge and discharge profile. And also the CoS2(400)/N,S-GO showing deep discharge behavior with stability up to 7.5 h.

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