Electrochemical Performances of Carbon-Coated Li[Li0.29Mn0.57Co0.14]O2 Cathode Materials for Lithium-ion Batteries

Carbon coated Mn-based Li-rich Li[Li0.29M0.57Co0.14]O-2 materials have been successfully prepared by glucose pyrolysis in air. X-ray diffraction (XRD) analyses inferred that the phase structure of layered oxide Li[Li0.29Mn0.57Co0.14]O-2 was not damaged during coating processing. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) revealed that the surface of Li[Li0.29Mn0.57Co0.14]O-2 particles was coated by carbon. Electrochemical tests presented the discharge capacities and the rate performances of Li[Li0.29Mn0.57Co0.14]O-2 were improved by carbon coating. At the current densities of 50 mA/g and 100 mA/g, the initial capacities of the sample modified by 10 wt% glucose increased by 85.7% and 241.5% than that of the sample without carbon coating. The electrochemical impedance spectroscopy (EIS) manifested the enhanced electrochemical performances for carbon coated samples could contribute to the reduction of the charge transfer resistance and solid electrolyte interphase resistance.