Microstructure and electrochemical properties of 3D flower-like CoS anode materials used for lithium ion batteries synthesized by one-step hydrothermal method

Using CoCl₂·6H₂O and thiourea (CH₄N₂S) as the raw materials, the 3D flower-like and spherical cobalt sulfide (CoS) anode materials used for lithium ion batteries were synthesized by one-step hydrothermal method in this paper, through changing the molar ratio of Co to S and adding the surfactant. In the results, when the molar ratio of Co to S is 1:1 and the hydrothermal reaction is carried out at 180 fo℃ r 12 h, the obtained 3D flower-like CoS anode materials are composed of nano-scale layer structures. By adding the cetyl trimethyl ammonium bromide (CTAB) as surfactant, the globular cobalt sulfide anode materials formed by the agglomeration of small particles are obtained by hydrothermal reaction at 180 for 12 h℃ when the molar ratio of Co to S is 1:1. The first discharge capacity of 3D flower-like CoS anode materials is 752 mAh·g^-1 at 0.1C, showing the good rate capability, and there is still high discharge capacity (185 mAh·g^-1) after 200 cycles at 1C without the tendency of decay, which is much higher than that of the spherical CoS anode materials (118.6 mAh·g^-1).