Improvement of Electrochemical Property of LiNi0.5Mn1.5O4 Spinel Material by Fluorine Substitution

Abstract

LiMn2O4 with spinel structure has received much attention for their low cost, low toxicity, and relatively high energy density. Despite such advantages, the significant capacity fading during cycling, especially at high temperature, hindered the commercial use of the LiMn2O4 as positive materials for lithium secondary battery. Although the origin of the poor cycling performance has not been fully understood, several possible mechanisms were suggested, including Jahn-Teller distortion, Mn dissolution at high temperature originated from the Mn3+/4+ redox, change in crystal lattice arrangement with cycling, and so on. The poor cycling behavior can be improved by replacing manganese ions with lithium ions Li1+xMn2-xO4 or by other metal cations LiMxMn2-xO4 (M=Mg, Ti, Cr, Fe, Co, Ni, Cu, and ) In this work, we have attempted to synthesize F-1 ion doped Li[Ni0.5Mn1.5]O4-xFx (0≤x≤0.1) materials. The structural and electrochemical properties of the prepared materials were characterized. Here, we would like to first introduce new fluorine doped 5V spinel Li[Ni0.5Mn1.5]O4-xFx cathode materials prepared by the ultrasonic spray pyrolysis method.