Investigation on the microscopic features of layered oxide Li[Ni 1 / 3 Co 1 / 3 Mn 1 / 3 ]O 2 and their influences on the cathode properties

Abstract

Three kinds of samples of Li[Ni 1 / 3 Co 1 / 3 Mn 1 / 3 ]O 2 were prepared respectively from direct solid-state reaction method, combustion method and co-precipitation route and their microscopic structural features have been investigated using Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), magnetic susceptibility measurement and X-ray photoelectron spectroscopy (XPS). The microscopic features such as uniform distribution of transition metal ions at 3b-site and the site-exchange ratio between lithium and nickel were found to be significantly dependent on the synthetic routes. The electrochemical properties of three samples were monitored using 2016 coin-cell by galvanostatic charge–discharge cycling test and cyclic voltammetry, which showed that the microscopic structural features are deeply related with the electrochemical performance. The obtained results also suggested that the combustion method may become a much simple alternative synthetic route to the complicate co-precipitation method.