Preparation and performance of 0.5Li2MnO3·0.5LiNi1/3Co1/3Mn1/3O2 with a fusiform porous micro-nano structure

Abstract

A new lithium-rich layered cathode material 0.5Li₂MnO₃·0.5LiNi_1/3Co_1/3Mn_1/3O₂ with a porous fusiform micro-nano structure has been successfully synthesized via a facile co-precipitation method followed by high temperature calcination. X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP-OES), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDXS) are used to characterize the chemical composition, structure, morphology and elemental distribution of the as-prepared lithium-rich layered material. It can be found that the as-prepared material presents a fusiform morphology and consists of interconnected nanosized subunits with a highly porous structure. The electrochemical measurements reveal that the material can deliver a high initial discharge capacity of 294.8 mA h g⁻¹ and an excellent capacity retention of 87.1% after 200 cycles at 0.5C between 2.0 V and 4.6 V. In particular, even at a high rate of 10C, the material can still deliver a high discharge capacity of 139.5 mA h g⁻¹. The excellent electrochemical performances can be ascribed to the unique fusiform porous micro-nano structure, which can facilitate the diffusion of lithium ions and enhance the structural stability of the lithium-rich layered cathode materials.