Effect of Li content on the electrochemical performance of Li1 + x (Mn0.675Ni0.1625Co0.1625)1 − x O2 cathode materials for high-power Li-ion batteries

Abstract

Li-rich Li1 + x (Mn0.675Ni0.1625Co0.1625)1 − x O2 (x = 0.1, 0.2, 0.3, and 0.4) materials were prepared using MCO3 precursors through hydrothermal treatment with using urea as precipitator. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge/discharge test are conducted to evaluate the physical and electrochemical properties of the spherical mesocrystal and resulting materials. Results show that the c/a ratio for the cathode material decreases and the layered structure deteriorates with increasing Li content. Li1.2Mn0.54Ni0.13Co0.13O2 (x = 0.2) exhibits the excellent electrochemical performance with an initial discharge capacity of 339 mAh g−1 at 20 mA g−1 and a capacity of 115 mAh g−1 at 400 mA g−1 after 50 cycles.