制备镍、钴、锰复合氢氧化物的热力学分析

合成化学计量的锂离子电池正极材料LiNi1/3Co1／3Mn1/3O2的关键在于制备均匀的前驱体。通过对M^2＋（Ni^2＋，CO^2＋，Mn^2＋）-NH3-OH^- -H2O体系的热力学分析，获得了M^2＋-NH3-OH^- -H2O体系中不同氨浓度时的lgM]-pH关系图（其中M为过渡金属元素），得到了以（NH4）2SO4为络合剂，以NaOH为沉淀剂，采用共沉淀法制备的锂离子电池正极材料用镍、钴、锰复合氢氧化物，较适宜的氨浓度为0．5mol／L左右，最佳共沉淀的pH值为12．0左右。在此氨浓度和pH值条件下通过共沉淀法制备了类球形的镍、钴、锰复合氢氧化物前驱体粉料，所得前驱体组分恒定，粒度分布均匀，中位粒径D50为14．76μm。

Thermodynamic analysis of preparation of multiple hydroxid of Ni, Co and Mn

The preparation of uniform precursor is the key to synthesize Li-ion battery cathode material LiNi1/3Co1/3Mn1/3O2. Thermodynamic analysis of M^2＋（Ni^2＋,Co^2＋,Mn^2＋）-NH3-OH^- -H2O system was proceeded, and lg M]-pH graphs at M^2＋（Ni^2＋,Co^2＋,Mn^2＋）-NH3-OH^- -H2O system with different NH3 concentrations were obtained. The multiple hydroxid powders of Ni, Co, Mn for L-ion battery positive material were prepared by co-precipitation method and using （NH4）2SO4 as complexing agent, NaOH as precipitant, and with the optimal NH3 concentration of 0.5mol/L, pH of about 12.0. The shape of precursor powders was sphere-like with a middle particle diameter D50 of 14.76μm, and with uniform size distribution.