查看文章

RuO₂ nanocrystals are successfully impregnated into the surface carbon layer of the Li₃V₂(PO₄)₃/C cathode material by the precipitation method. Transmission electron microscopy shows that the RuO₂ particles uniformly embed in the surface carbon layer. Cyclic voltammetry and electrochemical impedance spectroscopy indicate that the coexistence of carbon and RuO₂ enables high conductivity for both Li ions and electrons and thus stabilizes the interfacial properties of the electrode, facilitates the charge transfer reactions, and improves the Li⁺ diffusion in the electrode. As a result, the Li₃V₂(PO₄)₃ cathode coated with the binary surface layer shows improved rate capability and cycle stability. Particularly, the material containing 2.4 wt % Ru exhibits the best electrochemical performance and delivers a discharge capacity of 106 mAh g^–1 at the 10 C rate with a capacity retention of 98.4% after 100 cycles.