HYSTERESIS OBSERVED IN QUASI OPEN-CIRCUIT VOLTAGE MEASUREMENTS OF LITHIUM INSERTION IN HYDROGEN-CONTAINING CARBONS

High capacities with large hysteresis were observed during lithium ins ertion in hydrogen-containing carbons heated at temperatures near 700 degrees C. Quasi open-circuit voltage (OCV) measurements were used to study these materials. Using a simple model developed previously [1], we can qualitatively model the result of the OCV measurement. It is be lieved that the lithium atoms bind near aromatic hydrogen at edge of e ach graphene layer in the materials. This activated process involves a carbon-carbon bonding change from (sp)(2) to (sp)(3) leading to large hysteresis during lithium insertion. (C) 1997 Published by Elsevier S cience S.A.