Effects of magnesium and chlorine co-doping on the structural and electrochemical performance of the spinel LiMn2O4 cathode materials

The lithium-ion battery cathode materials spinel LiMn2O4 and LiMg0.05Mn1.95O3.9Cl0.1 samples are synthesised by solid state reaction route, the effects of magnesium and chlorine co-doping on the structure, morphology and electrochemical performance of material LiMn2O4 are studied by X-ray diffraction, scanning electron microscope, electron diffraction spectroscope and galvanostatic charge–discharge, respectively. The results indicate that appropriate amount doping of magnesium and chlorine does not change the spinel structure of LiMn2O4, and the results reveal that the LiMg0.05Mn1.95O3.9Cl0.1 has an initial discharge capacity of 125.2 mAh/g at 0.2C, and the capacity retention is still as high as 89.3% even after 100 cycles, which is significantly higher than 79.6% of LiMn2O4. Especially, the LiMg0.05Mn1.95O3.9Cl0.1 shows the discharge capacity of 91.2 mAh/g at 10C, which higher than that of LiMn2O4 (64.3 mAh/g). The LiMg0.05Mn1.95O3.9Cl0.1 exhibits excellent cycling performance and rate capability than that of LiMn2O4. Thus, this is a very effective way for comprehensive improving LiMn2O4 electrochemical performance.