Controlled synthesis of Li1.17Ni0.21Mn0.54Co0.08O2 as a cathode material for Li ion batteries

Abstract

Abstract Li-rich layered oxides Li1+xMO2 (M: Ni, Co, Mn) being a combination between Li2MnO3 and LiMO2, are considered as attractive high-capacity electrode materials for Lithium ion batteries. Here, we present the composition Li1.17Ni0.21Mn0.54Co0.08O2 with low cobalt content. The synthesis process was optimized by varying the pH of the co-precipitation step and pure phase was obtained only for pH\xa0=\xa011.3. The morphology of the material consists on the agglomeration of quasi-spherical particles an average particle size of 157\xa0nm. The electrochemical properties of this electrode material were investigated, and a specific capacity of 250\xa0mAh/g was recorded in the voltage range of 2–4.8\xa0V. While the first charge process evidenced a potential plateau at 4.5\xa0V corresponding to the oxygen redox activity, the subsequent electrochemical behavior is governed by Ni2+/Ni4+ and Co3+/Co4+ redox couples. When cycled for 40 charge/discharge cycles at 0.1C rate, the capacity retention is still good and remains around 85% with a coulombic efficiency of around 98%. The comparison of the obtained performances with those of existing Li-rich electrode materials show the excellent features of the studied Li-rich material for the next generation Lithium-ion batteries.