LiMgxMn2-xO4 (x <= 0.10) cathode materials with high rate performance prepared by molten-salt combustion at low temperature

摘要

LiMgxMn2-xO4 (x <= 0.10) cathode materials for lithium-ion batteries were prepared by molten-salt combustion and then structurally characterized by powder X-ray diffraction. All the cathode materials were identified as the spinel structure of LiMn2O4 and the lattice parameter decreased as the Mg content of LiMgxMn2-xO4 increased. Scanning electron microscopy revealed that the average particle size and agglomeration decreased with increasing Mg content. Galvanostatic charge discharge experiments showed that Mg doping could effectively enhance the cycling performance of the cathode materials. LiMg0.05Mn1.95O4 demonstrated excellent electrochemical performance with an initial discharge specific capacity of 122.0 mA h g(-1) and capacity retention of 86.4% after 100 cycles at 0.5 C (1 C=148 mA g(-1)). Rate performance, cyclic voltammetry and electrochemical impedance spectroscopy measurements showed that the Mg-doped spinels had high rate capability and reversible cycling performance. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.