Preparation of carbon monoliths having tailored pore structure from porous polymer precursors

This work concerns preparing tailored porous carbon monoliths by pyrolyzing porous polymer precursors. Prior work in this laboratory (1) demonstrated that a low density (0.05 g/cm3), high void fraction (97 vol%) carbon monolith could be prepared by pyrolyzing a porous poly(acrylonitrile) (PAN) precursor. A higher density, more robust carbon material is preferred for certain applications, such as electrodes for electrochemical devices. The present work demonstrates that porous carbon monoliths having mass density of 0.7 g/cm3 can be prepared from a porous PAN precursor if the pyrolysis is controlled carefully. The macropore structure of the carbon is adjusted by changing the pore structure of the PAN precursor, and the finer scale structure (such as the crystallite size Lc) is adjusted by varying the pyrolysis or heat treatment temperature