Synthesis and Electrochemical Properties of Li[Ni1/3Co1/3Mn1/3]1-xLax O2 Cathode Materials

Compounds of Li[Ni1/3Co1/3Mn1/3]1-xLaxO2 (0 ≤ x ≤ 0.04) system as cathode materials for lithium ion batteries were prepared by heating the sol-gel precursor. The samples were characterized by X-ray diffraction (XRD) and their electrochemical properties were investigated in terms of the cycling behavior and electrochemical impedance spectroscopy (EIS) response. It was found that the substitution of transition metals by lanthanum produced a complex change in lattice parameters, thereby induced change in electrochemical properties. Specific capacity and cycling performance of the samples were improved with the increase of lanthanum content. But high lanthanum content (x = 0.04) deteriorated its cycling performance renewedly, which was probably related to the structural instability caused by excessive lanthanum introduction.