Nanostructure of mesophase pitch-based graphite in the matrix of C/C composite

Mesophase pitch-based C/C composite is one of the best candidate materials for high thermal conductivity. In this work, the fine microstructure of its matrix has been analyzed by high-resolution transmission electron microscopy (HRTEM). Interestingly, although the results show that the matrix is composed of hexagonal graphite, the [11-20] and [10-10] zone axes coexist in the same pattern (at variance with traditional diffraction theory). Furthermore, a large number of differently oriented nanostructures interwoven with the main hexagonal graphite have been identified by a series of tilting diffraction patterns, dark-field images, and high-resolution TEM images. The relative positional relationship between these nanostructures and the main graphite has been obtained. This paper provides a theoretical basis for the improvement of thermal conductivity and other properties (such as Li+ and Na+ storage) of mesophase pitch-based C/C composites.