Construction of Carbon-Coated Cobalt Sulfide Hybrid Networks Inter-Connected by Carbon Nanotubes for Performance-Enhanced Potassium-Ion Storage

Comprehensive Summary Because of its high theoretical capacity, transition metal sulfides have always been regarded as promising anode materials for potassium-ion batteries. However, it is difficult for us to make use of transition metal sulfides due to their low conductivity, poor ionic diffusivity, sluggish reaction kinetics and severe volume expansion. Here, we developed a novel carbon-coated CoSx@CNT material with carbon nanotubes inter-connected (CCS@CNT), which shows an excellent potassium storage performance with a specific capacity of 550 mA center dot h center dot g(-1) under the current of 50 mA center dot g(-1) and 296 mA center dot h center dot g(-1) at 1000 mA center dot g(-1). The carbon layer can effectively alleviate volume expansion during charging and discharging process. And this special structure of inter-connected hybrid networks with CNTs greatly improves the electron transport, ion diffusion coefficient and reaction kinetics of the material.