Synthesis and characterization of LiNi0.5-xMn 1.5-yMx+y,O4 for 5V cathode material by mechanochemical process

Abstract

Recently, the high-voltage nickel-substituted manganese spinel is considered as one of the most promising alternatives for LiCoO2 because it can deliver a high discharge voltage profile (∼4.7V) and a large 5V region capacity compared with other candidate materials. In this work, the electrochemical performance of this material was improved by doping with aluminum or chromium through the mechanochemical process. From the previous studies, it was known that the degradation of the high-voltage spinel is very dependent on the existence of Mn3+, which is closely related with formation of inactive Li2Ni1-2O phase in LiNi 0.5Mn1.5O4 spinel. It was observed that highly homogenous precursors with aimed composition can be readily obtained through the mechanochemical process and after an appropriate heat-treatment, high-voltage spinel with a negligible 4V plateau can be easily synthesized using ball-milled powders, which was certified by elemental composition analysis, X-ray diffraction pattern studies, and the electrochemical cycling data. copyright The Electrochemical Society.