Dispersion of Li[Ni 0.2 Li 0.2 Mn 0.6 ]O 2 Powder by Surfactant for High-power Li-ion Cell

• Published in: Bulletin of the Korean Chemical Society Vol. 30; no. 7; pp. 1598 - 1602
• Main Authors: Yun, Su-Hyun, Park, Yong-Joon
• Format: Journal Article
• Language: Korean
• Published: 2009
• Subjects: Rate performance; Cathode; Battery; Surfactant; Dispersion
• ISSN: 0253-2964; 1229-5949

The particle size of Li[$Ni_{0.2}Li_{0.2}Mn_{0.6}]O_2$ cathode powder was controlled effectively by dispersion using lauric acid as a surfactant. The samples treated by lauric acid showed smaller particles of approximately half the original size compared to the particles of a pristine sample. A structural change due to the dispersion of Li[$Ni_{0.2}Li_{0.2}Mn_{0.6}]O_2$ powder was not detected. The rate performance of the Li[$Ni_{0.2}Li_{0.2}Mn_{0.6}]O_2$ cathode was improved by dispersion using lauric acid, which was likely due to the decrease of the particle size. In particular, a sample dispersed pristine powder using lauric acid (L2) presented a greatly enhanced discharge capacity and capacity retention at a high C rate. The discharge capacity of a pristine sample was only 133 m$Ahg^{-1}$ (3C rate) and 96 m$Ahg^{-1}$ (12C rate) at the tenth cycle. In contrast, the L2 electrode delivered higher discharge capacities of 160 m$Ahg^{-1}$ (3C rate) and 129 m$Ahg^{-1}$ (12C rate) at the tenth cycle. The capacity retention at a rate of 12C/2C was also enhanced from ~ 45% (pristine sample) to 57% (L2) by treatment with lauric acid.