| Development of Petroleum-Based Carbon Composite Materials Containing Graphite/silicon Particles and Their Application to Lithium Ion Battery Anodes |
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Soon-Young Noh, Young-Hoon Kim, Chul-Wee Lee, Song-Hun Yoon |
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Green Chemistry Division, Korea Research Institute of Chemical Technology (KRICT);Green Chemistry Division, Korea Research Institute of Chemical Technology (KRICT);Green Chemistry Division, Korea Research Institute of Chemical Technology (KRICT);Green Chemistry Division, Korea Research Institute of Chemical Technology (KRICT); |
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| Abstract |
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Herein, a novel preparation method of highly homogeneous carbon-silicon composite materials was presented. In contrast to conventional solvent evaporation method, a milled silicon-graphite or its oxidized material were directly reacted with petroleum-derived pitch precursor. After thermal reaction under high pressure, pitch-graphite-silicon composite was prepared. Carbon-graphite-silicon composite were prepared by an air-oxidization and following carbonization. From energy dispersive spectroscopy, it was observed that small Si particles were highly embedded within carbon, which was confirmed by disappearance of Si peaks in Raman spectra. Furthermore, X-ray diffraction and Raman spectra revealed that carbon crystallinity decreased when the strongly oxidized silicon-graphite was added, which was probably due to oxygen-induced cross-linking. From the anode application in lithium ion batteries, carbon-graphite-silicon composite anode displayed a high capacity ($565;mAh;g^{-1}$), a good initial efficiency (68%) and an good cyclability (88% retention at 50 cycles), which were attributed to the high dispersion of Si particles within cabon. In case of the strongly oxidized silicongraphite addtion, a decrease of reversible capacity was observed due to its low crystallinity. |
| Key Words:
Pitch-graphite-Si composite, Petroleum pitch, Anode in lithium ion batteries |
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