Layered lithium-rich oxide nanoparticles: low-temperature synthesis in mixed molten salt and excellent performance as cathode of lithium-ion battery

摘要

Layered lithium-rich oxide, 0.5Li(2)MnO(3)center dot 0.5LiMn(1/3)Ni(1/3)Co(1/3)O(2), is synthesized in a mixed molten salt of KCl and LiCl under 750 degrees C. Its morphology and structure are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption and desorption isotherm, and its performances as cathode of lithium-ion battery are investigated by charge-discharge test and electrochemical impedance spectroscopy, with a comparison of the samples synthesized via solid-state reaction. It is found that the resulting product consists of uniform nanoparticles, 50 nm in average, which possesses a well crystallite layered structure although its synthesis temperature is low and thus exhibits excellent cyclic stability and rate capability. The resulting product delivers an initial discharge capacity of 268 mAh g(-1) at 0.1 C and has a capacity retention of 82% after 100 cycles at 1 C, compared to the 243 mAh g(-1) and 73% for the sample synthesized by solid-state reaction under 900 degrees C.