Co9S8/CNTs Microspheres As Superior-Performance Cathodes in Aqueous Ammonium-Ion Batteries

Coated Co9S8/carbon nanotube (Co9S8/2CNTs) microspheres were constructed and successfully applied to aqueous ammonium-ion batteries. The introduction of carbon nanotubes in the Co9S8 microspheres increased the electronic conductivity, shortened the diffusion distance for NHa ions and improved the buffering ability against volume changes in the cycling processes. As a result, Co9S8/2CNTs microspheres had a reversible capacity of 112 mA center dot h/g at 0.1 A/g. In addition, the ammonium ion energy storage mechanism accompanied by the formation of reversible phase transition product CoSO4 center dot 6H2O and establishment/breaking of intermolecular hydrogen bonds in Co9S8/2CNTs was investigated.