Low temperature milling of the LiNH(2) + LiH hydrogen storage system

Abstract

Ball milling of the LiNH(2) + LiH storage system was performed at 20 degrees C, -40 degrees C, and -196 degrees C, and the resulting powders were analyzed using X-ray diffraction, scanning electron microscopy, nuclear magnetic resonance (NMR), specific surface area analysis, and kinetics cycling measurements. Ball milling at -40 degrees C showed no appreciable deviations from the 20 degrees C sample, but the -196 degrees C powder exhibited a significant increase in the hydrogen desorption kinetics. NMR analysis indicates that a possible explanation for the kinetics increase is the retention of internal defects generated during the milling process that are annealed at the collision site at higher milling temperatures. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All lights reserved