Layer disorder in carbon anodes

Inter- and intra-layer disorder in a representative hard carbon derived fro m epoxy novolac resin at 1000 degrees C have been investigated by comparing both the elastic structure factor S(Q) and radial distribution function ob tained from pulsed neutron time-of-flight measurements with calculations fr om simple hypothetic systems with specific disorder characteristics. The sp atial relationship between these building blocks, planar graphene fragments with length scale of 1 nm, is probed in terms of inter-layer alignment and intra-layer connectivity. Coupled with the density of dangling bonds obtai ned from ESR and residual hydrogen concentration, these simulations provide sufficient information to construct an overall model of the carbon structu re. Of special interest is the physical origin of the ubiquitous broad (002 )-like reflection frequently interpreted as that from layers with a uniform interlay spacing (d(002)) It is found to be directly related to the misali gnment between layers with an average interlayer spacing as that in crystal line graphite (3.35 Angstrom). (C) 1998 Published by Elsevier Science Ltd. All rights reserved.