Preparation and Electrochemical Properties of Carbon-Coated CoCO3 as an Anode Material for Lithium Ion Batteries

Diamond-shaped carbon-coated CoCO3 (CoCO3/C) particles were prepared by a simple hydrothermal method, and carbon coating was realized using glucose as the carbon source. This study focuses on the electrochemical performance of CoCO3/C as an anode material. Its surface morphology and crystal lattice structure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The content and structure of the carbon coating layer were further investigated by the thermogravimetry-differential thermal analysis (TG-DTA) technique and Raman spectroscopy. The pore size distribution was characterized using the Barrett-Joyner-Halenda (BJH) method. The results show that the carbon coating process creates not only a layer of amorphous carbon on the surface of CoCO3, but also a porous structure with pore size of similar to 30 nm. The amorphous carbon layer enhances the structural stability during the charging and discharging process, and the porous structure facilitates the movement of ions in the electrolyte, and thus improves its electrochemical performance. When the cycling performance was tested for 500 cycles, this CoCO3/C material maintained a capacity of 539 mAh g(-1) at 0.90C (1.00C = 450 mA center dot g(-1)), showing its excellent cycling capacity. When the current rate was increased to 3.00C, the capacity was 130 mAh g-1. When the current rate was returned to 0.15C, its capacity was 770 mAh g(-1), demonstrating the great rate performance and stability of CoCO3/C.