Electrochemical performance of La2O3-coated layered LiNiO2 cathode materials for rechargeable lithium-ion batteries

Abstract

Uncoated and La2O3-coated LiNiO2 cathode materials were synthesized by polymeric sol gel process using metal nitrate precursors at 600 °C for 10 h. The structure and electrochemical properties of the surface-coated LiNiO2 materials were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry, charge/discharge and electrochemical impedance spectroscopy techniques. X-ray powder diffraction and SEM result show that no significant bulk structural differences were observed between the lanthanum oxide coated and pristine LiMn2O4. The galvanostatic charge/discharge studies on the uncoated and lanthanum oxide-coated LiNiO2-positive material at 0.5-C rate in the potential range between 3 and 4.5 V revealed that lanthanum oxide-coated positive electrode material has enhanced charge/discharge capacities; 2.0 wt.% of lanthanum oxide-coated LiNiO2-positive material has satisfied the structural stability, high reversible capacity and high electrochemical performances.