Surface Basicity Induced RuO2 Modification on Nanosized Li-Rich Cathode Li1.26Fe0.22Mn0.52O2 with Superior Electrochemical Performance

In this study, nanosized Li1.26Fe0.22Mn0.52O2 are modified with conductive RuO2 by using the surface basicity of Li-rich materials in aqueous solution to induce a chemically deposit of Ru3+. No additional precipitant is added. After heat-treatment, RuO2 modifies the surface of nano-particles verified by Energy Dispersive Spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS). The deposition process accompanies chemical-delithium activation of Li2MnO3 component. As a result, the intensity of superlattice peaks distinctly reduces monotonously in XRD patterns. And the electrode performances about the initial coulombic efficiency, the capacity and rate capability are improved greatly. In addition, for RuO2 modified samples, a new discharge plateau around 2.8 V appears, which is ascribed to spinel-like structure, enhancing the electrochemical activity of electrode. This facile modification method adopted in the work can be feasible and beneficial toward advanced Li-rich cathode materials.