Effect of Preparation Parameters on Microstructure of Ni0.8Co0.1Mn0.1(OH)2 Precursors.

The electrochemical performance of materials largely depend on the quality of precursor. Co-precipitation is an effective way to attain an excellent morphology, particle size and distribution of particles, which is still a huge challenge in pH regulation of the reaction system to influence supersaturation. Here, Ni_0.8Co_0.1Mn_0.1 (OH)₂ precursors were prepared as an example by regulating Ni²⁺ concentration in the supernatant instead of adjusting pH value, and the effect of preparation process parameters on microstructure of precursor was evaluated quantitatively. Particle size distribution of Ni_0.8Co_0.1Mn_0.1(OH)₂ precursor was evaluated from SEM images, and the electrochemical performance of LiNi_0.8Co_0.1Mn_0.1O₂ cathode materials were studied using LAND battery test system. The results showed that more homogeneous particle size distribution was attained in samples prepared by regulating concentration of Ni²⁺ in supernatant than with pH regulation. Average particle size increased from 4.1 to 5.9 μm, and peak width at half height were 1.37 and 1.16 μm, respectively. Same conclusions could also drawn from standard deviation, peak area and peak height data. Electrochemical data demonstrate that rate capabilities were 206.7, 183.2, 171, 161.8, and 145.5 mA h/g from 0.1 to 10 C, respectively and capacity retention was 86.6% after 100 cycles at 1 C, which were better than the pH regulation progress. These results indicate that regulation of concentration of Ni²⁺ in supernatant has better performance and is suitable for industrial applications. [ABSTRACT FROM AUTHOR]