Dual coating strategy of CoS 2 @Co@C toward fast insertion/extraction anode material for sodium‐ion batteries

Summary Rechargeable sodium‐ion batteries are facing the challenge of highly electrochemical active anode for their realization. In this study, we report a dual coating strategy of CoS 2 with metallic Co particles and carbon to boost the charge transfer and stability. The phase of CoS 2 and the existence of Co metallic particles were confirmed using x‐ray diffraction (XRD). x‐ray photoelectron spectroscopy (XPS) results corroborate the presence of carbon and CoS bonding. The prepared CoS 2 @Co@C anode reveals high performance where it shows a capacity of 712 mA h g −1 at 0.05 C rate. The CoS 2 @Co@C electrode exhibits exceptional high rate capability where it exhibits a capacity of 260 mA h g −1 at elevated rate of 10.0 C. The cyclability of CoS 2 @Co@C anode is tested at 0.05 C and 0.5 C rates where the electrode shows 78% and 45% capacity retention of stabilized capacity. The reaction mechanism of the CoS 2 @Co@C electrode is determined using x‐ray absorption spectroscopy (XAS) and the results show reversibility of the material.