Hydrogen absorption over Li-carbon complexes

Abstract

A remarkable reduction in reaction temperature was found for the hydrogenation of Li metal in Li-C mixture. H2 uptake started at 50°C, became vigorous at 150°C and slowed down at temperatures above 200°C. In-situ XRD characterizations revealed that Li-C intercalation compounds such as LiC6 and LiC12 existed in the Li-C samples, and LiH formed after the hydrogenation taking place. Increasing the carbon content in the Li-C mixture, from Li/C = 10:1 to 5:1 and then to 2:1, would enhance the reactivity of hydrogenation accordingly. Carbon nanotubes, with smaller size and larger specific area, showed even greater enhancement of the hydrogenation of lithium metal than graphite. The mechanism for the low temperature hydrogenation of Li-C samples was studied and discussed.