Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University , Changchun 130012, People's Republic of China.
ACS Appl Mater Interfaces. 2014 Aug 13;6(15):12523-30. doi: 10.1021/am502387z. Epub 2014 Jul 23.
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.
RuO2 纳米晶通过沉淀法成功地浸渍到 Li3V2(PO4)3/C 正极材料的表面碳层中。透射电子显微镜表明 RuO2 颗粒均匀地嵌入表面碳层中。循环伏安法和电化学阻抗谱表明，碳和 RuO2 的共存使锂离子和电子具有高导电性，从而稳定了电极的界面性质，促进了电荷转移反应，并提高了电极中的 Li(+)扩散。结果，涂覆有二元表面层的 Li3V2(PO4)3 正极表现出改善的倍率性能和循环稳定性。特别是，含有 2.4wt%Ru 的材料在 10C 倍率下表现出最佳的电化学性能，在 100 次循环后具有 106mAh g(-1)的放电容量和 98.4%的容量保持率。
