文摘
Cr doped 0.3Li2MnO3路0.7LiMn0.35鈭?/sub>x/3Ni0.5鈭?/sub>x/3Co0.15鈭?/sub>x/3CrxO2 (x = 0, 0.02, 0.04, 0.06) as a cathode material for Li-ion battery has been successfully synthesized by spray drying and subsequent calcination. The effects of Cr dopant on the structural and electrochemical properties of this material have been investigated by XRD, SEM, EDS, charge-discharge measurements, Ac impedance spectroscopy as well as cyclic voltammetry. These results demonstrated that the element Cr distributed uniformly in these materials. With the Cr content increasing, lattice parameters a and c decrease and less Li ion locates in transition metal site. Among the synthesized Cr-doped materials, when x = 0.04, this material shows the best electrochemical properties. Between 2.5 and 4.8 V (vs. Li/Li+), the initial discharge capacities of the materials increased from 143 to 168 mA h g鈭? at a constant current density of 250 mA g鈭?. After 50 cycles, the capacity retention of the materials raised from 83% to 93%.
