Improving the Electrochemical Performance of Li1.14Ni0.18Mn0.62O2 by Modulating Structure Defects via a Molten Salt Method

Nanocrystalline Li1.14Ni0.18Mn0.62O2 cathode materials are synthesized by a molten salt method using KCl as the molten agent. The influence of the sintering temperature and the mass ratio of KCl to Li1.14Ni0.18Mn0.62O2 on the structure and electrochemical performance are investigated. The sintering temperature can markedly affect the formation of the layered structure and the content of stacking faults. The amount of KCl influences the cation ordering of the materials. The ratios of Li+/Ni2+ replacement for the materials obtained at 800°C with a KCl amount of R=4, 8, and 12 [R=m(KCl)/m(Li1.14Ni0.18Mn0.62O2)] are 16.51, 8.39, and 4.46%, respectively. A lower steric hindrance-related to a better cationic ordering-is obtained when the amount of KCl is increased, which is in agreement with the tendency of the Li+ diffusion coefficient. This study demonstrates a new approach to control the Li+/Ni2+ replacement in lithium-rich layered cathode materials to improve their electrochemical performance.

Duke Scholars

Author Jie Liu Chemistry