摘要
Properties of two LiFePO4/C composites with low carbon content synthesized from precursors dried by spray drying and blast drying are investigated by scanning electron microscopy, X-ray diffraction, Raman spectroscopy and electrochemical measurements. The two samples have a different morphology and particle size, while the structure of LiFePO4 is unaffected. The LiFePO4/C composite prepared from the precursor dried by blast drying has a much lower surface resistance and a much better rate capability because the deposited carbon is more graphite-like and more conductive. The cycling performance is also much better for the LiFePO4/C composite prepared from the precursor dried by blast drying because only a slight impedance growth is involved upon cycling. These results suggest that the precursor drying process has a significant impact on the properties of LiFePO4/C composite, and its effect is highly dependent on the carbon content.
Properties of two LiFePO4/C composites with low carbon content synthesized from precursors dried by spray drying and blast drying are investigated by scanning electron microscopy, X-ray diffraction, Raman spectroscopy and electrochemical measurements. The two samples have a different morphology and particle size, while the structure of LiFePO4 is unaffected. The LiFePO4/C composite prepared from the precursor dried by blast drying has a much lower surface resistance and a much better rate capability because the deposited carbon is more graphite-like and more conductive. The cycling performance is also much better for the LiFePO4/C composite prepared from the precursor dried by blast drying because only a slight impedance growth is involved upon cycling. These results suggest that the precursor drying process has a significant impact on the properties of LiFePO4/C composite, and its effect is highly dependent on the carbon content.
基金
supported by the National Key Basic Research and Development Plan (2011CB935904)
