Abstract
Spherical phenolic resin powders with two particle sizes, i.e. the average particle sizes of 25 and 9.1 μm, were treated in Ar-H2, Ar-N2, Ar-H2-CO2 and Ar-N2-CO2 RF thermal plasma under reduced pressures of 26.6 and 53.3 kPa. The plasma-treated powders were characterized by X-ray diffractometry, scanning electron microscopy and Raman spectroscopy. The BET surface area and the content of carbon, hydrogen, oxygen and nitrogen were also measured. The plasma-treated powders were heated in-flight and carbonized through thermal decomposition, and partially evaporated. For the powder of the smaller particle size, more amount of evaporation occurred and a lot of fine powders were formed. The larger particle powder had a higher degree of crystallinity than the small particle one as examined by the X ray diffraction patterns and Raman spectra. The plasma-treated powders have a non-uniform structure, which is composed of the graphitized and amorphous structures, and the phase content depended on the particle size. Electrochemical measurements as an anode of lithium rechargeable battery were performed in 1 M LiClO4/ (ethylene carbonate+diethyl carbonate). Some powder samples of the plasma-treated powders showed higher capacity than theoretical capacity of graphite, 372 mAh/g.
