STRUCTURAL CHARACTERIZATION OF MILLED MESOPHASE PITCH-BASED CARBON-FIBERS

The microstructure of milled mesophase pitch-based carbon fibers (mMPC Fs) that have been developed as an anode material for Li ion batteries has been studied as a function of heat treatment temperature (HTT) ma inly by Raman spectroscopy, and the results obtained are compared with those by X-ray diffraction (XRD) and scanning electron microscopy (SE M) observations. As a functional material, SEM measurements indicate t hat these mMPCFs have a characteristic controlled cross-sectional morp hology like a bamboo skin structure which is different to that of conv entional mesophase pitch-based carbon fibers for composite use. The mM PCFs with HTT>2000 degrees C clearly show the 110 and 112 XRD peaks in dicating the development of three-dimensional graphite stacking from a turbostratic structure. The mMPCFs heat-treated at temperatures >2000 degrees C contain larger domain sizes along their longitudinal surfac e that those along the periphery of the fiber, as demonstrated by micr oprobe Raman scattering experiments. These mMPCFs could be promising a s a functional material for applications, such as to Li ion batteries, but not for composite applications. (C) 1998 Elsevier Science Ltd. Al rights reserved.