The effect of LaF3 coating on the structural and electrochemical properties of Li[Ni0.3Co0.4Mn0.3]O2 cathodes was investigated using XRD, SEM, TEM, and a cycler. The coating layer consisted of nano-sized particles attached nonuniformly to the surface of pristine powder. Despite the surface coating treatment, phase difference by LaF3 coating was not detected. The discharge capacities of coated electrodes were a little lower than that of pristine sample at a 1 C rate. However, as the C rate increases, the capacity retention of the coated sample becomes obviously superior to that of the pristine sample. The cyclic performances of the electrodes in the voltage range of 4.8 ~ 3.0 V were also improved by the surface coating. Such enhancement is attributed to the presence of the LaF3 coating layer, which effectively suppressd the reaction between electrodes and electrolytes on the surface of the Li[Ni0.3 Co0.4Mn0.3]O2 electrode.

Key Words: Surface coating, Electrochemical property, Cathode, Lithium battery