共沉淀法合成高镍三元Ni0.8Co0.1Mn0.1(OH)2前驱体的可控制备

影响高镍三元材料性能的关键步骤在前驱体的制备,利用共沉淀法制备前驱体,底液氨水浓度作为三元前驱体制备的重要控制条件,可以对前驱体的形貌产生非常大的影响,从而影响成品正极材料的电化学性能。通过控制共沉淀制不同氨水底液浓度制备了三组样品材料。利用SEM、XRD考察了对结构的影响,并进一步探究了材料的电化学性能。结果表明,底液氨水浓度对合成组分均一、形貌均匀的前躯体十分重要,且直接影响烧结后的LiNi_0.8Co_0.1Mn_0.1O₂正极材料的电化学性能。利用相同的共沉淀反应条件,底液氨水浓度0.5mol/L条件下合成得到的前躯体材料表现出更为优异的倍率和循环性能,在0.1 C、0.2C、0.5C、1C、2C、5C和10C下的放电比容量分别为168.8 mAh/g、161.6 mAh/g、153.2 mAh/g、144.4 mAh/g、133.2 mAh/g、88.5 mAh/g和5.7mAh/g。

Controlled fabrication of high nickel ternary Ni0.8Co0.1Mn0.1(OH)2 precursors by co-precipitation method

The preparation of precursors is the key step to affect the properties of high nickel ternary materials. The concentration of ammonia in the bottom liquid is an important control condition for the preparation of ternary precursor system, durning the precursors were prepared by co-precipitation method. The concentration of ammonia in the bottom solution can have a great influence on the morphology of the precursor, thus affecting the electrochemical properties of the finished cathode materials. Three groups of sample materials were prepared by controlling co-precipitation with different concentration of ammonia water substrate. SEM and XRD were used to investigate the influence of the structure, and further explore the electrochemical properties of the material. The results showed that the concentration of ammonia in the bottom solution was very important for the precursor with uniform composition and uniform morphology. Moreover, the electrochemical properties of sintered LiNi0.8Co0.1Mn0.1O2 cathode materials are directly affected. Using the same co-precipitation reaction conditions, under the condition of 0.5mol/L ammonia concentration in the bottom solution, the precursor material showed better rate and cycling performance. The discharge specific capacities at 0.1C, 0.2C, 0.5C, 1C, 2C, 5C and 10C are 168.8 mAh/g, 161.6 mAh/g, 153.2 mAh/g, 144.4 mAh/g, 133.2 mAh/g, 88.5 mAh/g and 5.7mAh/g, respectively.