Synthesis and electrochemical properties of LiNi_(0.5)Mn_(1.5)O_4 cathode materials for lithium-ion batteries

The lithium-ion battery cathode material LiNi0.5Mn1.5O4 with cubic spinel structure were synthesized by a chemical route using Li(CH3COO).2H2O,Ni(CH3COO)2.4H2O,Mn(CH3COO)2.4H2O and H2C2O4.2H2O as raw materials,and polyethylene glycol 20000as dispersant.The evaluation of the synthesized samples were carried out by using X-ray diffraction,scanning electron microscopy and charge-discharge tests.When calcinated at 850℃,the LiNi0.5Mn1.5O4samples show the best electrochemical performance.The specific discharge capacities were 132.9,117.3,111.2,104.8and 91mAh/g at 0.2,0.5,1,2,5C(1C=146.7mAh/g)rates in the range of 3.5-4.9V,and after 20cycles the capacity retention are 93.2%,98.9%,97.4%,97.3%,95.5%,respectively.