Surface Modification of LiCo_1/3Ni_1/3Mn_1/3O₂ with LaF₃ for Lithium-Ion Batteries

Abstract

LiCo 1/3 Ni 1/3 Mn 1/3 O 2 has been modified with LaF 3 . The surface modified materials were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and galvanostatic charge-discharge cycling. The LaF 3 -coated LiCo 1/3 Ni 1/3 Mn 1/3 O 2 had an initial discharge specific capacity of 178.0 mAh•g–1 within the potential ranges 2.75–4.5 V (vs. Li+/Li), and its discharge specific capacity is 168.7 mAh•g–1 after 50 cycles, much higher than that of the pristine LiCo 1/3 Ni 1/3 Mn 1/3 O 2 (148.4 mAh•g –1 ). The improvement could be attributed to the LaF3 coating layer that hinders interaction between LiCo 1/3 Ni 1/3 Mn 1/3 O 2 and electrolyte and stabilizes the structure of LiCo 1/3 Ni 1/3 Mn 1/3 O 2 .