Molten salt-assisted template synthesis of lithium-rich layered oxide 0.3Li2MnO3·0.7LiNi1/3Co1/3Mn1/3O2 nanorods as lithium-ion battery cathode

Abstract

Lithium-rich layered oxide 0.3Li2MnO3·0.7LiNi1/3Co1/3Mn1/3O2 nanorods have been prepared by a KCl molten salt-assisted template route. The nanorods can well retain the rod-like structure of a β-MnO2 template, and have the length of several hundred nanometres and diameters of about one hundred nanometres. In comparison with the sample obtained from immediate solid-state reaction, the molten salt treatment can help improve the phase purity and decrease the particle size. As a lithium-ion battery cathode, the KCl-treated nanorods deliver an initial discharge capacity of 242.9 mAh g-1 with a high Coulombic efficiency of 83.6% at a current density of 20 mA g-1 within 2.0-4.7 V. After 60 cycles, a discharge capacity of 150.8 mAh g-1 can be retained at 0.5 C. Even at a high charge-discharge rate of 4 C (800 mA g-1), a stable capacity of 104.2 mAh g-1 can be reached, while the sample obtained from solid-state reaction only delivers an initial discharge capacity of 179.1 mAh g-1at 20 mA g-1.