Effects of Surface Modification with Ag/C on Electrochemical Properties of Li[Li0.2Mn0.54Ni0.13Co0.13]O2

A lithium-rich solid-solution layered cathode material, Li[Li0.2Mn0.54Ni0.13Co0.13]O2, was synthesized using a fast co-precipitation method, and surface modified with Ag/C via chemical deposition. The electrochemical properties, structures, and morphologies of the prepared samples were investigated using Xray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), galvanostatic charge-discharge cycling, cyclic voltammetry (CV), electrochemical impedance spectra (EIS), and energy dispersive X-ray spectroscopy (EDS). The XRD results showed that the pristine and Ag/Ccoated cathode materials both have hexagonal α-NaFeO2 layered structures with the R3m space group. Microscopic morphological observations and EDS elemental mapping showed that a uniform Ag/C coating layer of thickness 25 nm was deposited on the surfaces of Li[Li0.2Mn0.54Ni0.13Co0.13]O2 particles. The Ag/C-coated Li[Li0.2Mn0.54Ni0.13Co0.13]O2 material gave an excellent electrochemical performance. The initial discharge capacity 1667 Acta Phys. -Chim. Sin. 2014 Vol.30