基于水热/溶剂热法制备不同形貌LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)锂离子电池正极材料

Preparation of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode materials with different morphologies based on hydrothermal/solvothermal method

基于水热/溶剂热法制备LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)电极材料,以镍、钴、锰乙酸盐为原料,以六亚甲基四胺为沉淀剂、水或乙醇为溶剂,通过调节溶剂组分控制Ni_(0.8)Co_(0.1)Mn_(0.1)(OH)_(2)(NCM)的成核与生长速率,从而合成两种形貌不同的Ni_(0.8)Co_(0.1)Mn_(0.1)(OH)_(2)前驱体,再经过混锂煅烧获得LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)正极材料,研究比较了其电化学性能。以水为溶剂通过水热法合成的前驱体样品呈现出由一次片状颗粒紧密堆积组成的长方体状二次颗粒形貌,经混锂煅烧得到的产物表现出较高的放电比容量,在0.5C倍率下首次放电比容量可达到189.70 mA·h/g,循环200次容量保持率为69.72%。以乙醇为溶剂通过溶剂热法合成得到球形二次颗粒前驱体,最终得到的产物具有多孔球形结构,表现出了优异的循环性能,0.5C首次放电比容量为178.65 mA·h/g,循环200次容量保持率仍高达94.55%。

LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)electrode material was prepared by hydrothermal/solvothermal method.Two precursors of Ni_(0.8)Co_(0.1)Mn_(0.1)(OH)_(2)with different morphology were synthesized by adjusting the solvent composition and controlling the nucleation and growth rate of Ni_(0.8)Co_(0.1)Mn_(0.1)(OH)_(2)with nickel,cobalt and manganese acetate as raw materials,hexamethylene tetramine as precipitant and water or ethanol as solvent.LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)cathode material was obtained by lithium mixed calcination,and its electrochemical property was studied and compared.By using water as the solvent,the prepared precursor composed of rectangular parallelepiped secondary particles was synthesized,which were assembled by plate-like primary particles.The obtained product exhibited a high specific discharge capacity of 189.70 mA·h/g and a capacity retention of 69.72% after 200 cycles at 0.5C.By using ethanol as the solvent,the spherical secondary particle precursor was synthesized.The final product was evolved into porous spherical structure and exhibited excellent cycle performance.It delivered a specific discharge capacity of 178.65 mA·h/g and a high capacity retention of 94.55% after 200 cycles at 0.5C.