一步水热法合成3D花状CoS锂离子电池负极材料的组织及电化学性能研究

以CoCl2·6H2O和硫脲(CH4N2S)为原料,采用一步水热法,通过改变钴硫摩尔比和添加表面活性剂制备出两种不同形貌(3D花状和球状)的硫化钴(CoS)锂离子电池负极材料。结果表明,当钴硫摩尔比为1:1时,在180℃下水热反应12 h可得到3D花状CoS负极材料,其三维立体花状结构由纳米级层片组成;当钴硫摩尔配比为1:1,添加十六烷基三甲基溴化铵(CTAB),在180℃下反应12 h可制得由小颗粒聚结成的球状CoS负极材料。在0.1C电流密度下,3D花状CoS电池首次放电比容量为752m Ah·g^-1,并且具有良好的倍率性能;在1C电流密度下,经过200圈的循环测试后,3D花状CoS电池仍有较高的放电比容量(185 mAh·g^-1),远高于球状CoS电池(118.6 mAh·g^-1),并且没有衰减的趋势。

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).