Preparation of porous Li1.2Mn0.54Ni0.13Co0.13O2 micro-cubes for high-capacity lithium-ion batteries

Abstract

Abstract We report on the preparation of Li1.2Mn0.54Ni0.13Co0.13O2 micro-cubes for the applications of high-capacity lithium-ion batteries. Metal oxalate precursors with a cubic morphology are firstly prepared via a coprecipitation method in the mixed solutions containing ethanol, methanol and water. After controlled calcination treatment, the metal oxalate precursors are transformed into Li-rich layered oxide micro-cubes which possess a porous micro-nano structure consisting of interconnected nano-sized subunits. It is observed that a small amount of Li4Mn5O12 spinel is integrated with the layered phase in the micro-cubes. Compared with the micro-long-rod counterpart which is prepared under similar condition but only possess layered structure, the micro-cube cathode has excellent electrochemical properties that not only possess a high capacity of 278 mA h g−1 with an initial Coulombic efficiency of 88.3%, but also outstanding capacity retentions of 99.3% after 100 cycles and 89.7% after 200 cycles at 1 C. The excellent electrochemical properties of Li1.2Mn0.54Ni0.13Co0.13O2 micro-cube cathode may arise from the contributions from both the porous micro-nano structure and Li4Mn5O12 spinel phase, which can enhance the efficient contact of electrolyte and the transportation of Li+ as well as maintain the structure stability.