Ball milling of the LiNH2 + LiH storage system was performed at 20°C, -40°C, and -196°C, and the resulting powders were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), specific surface area (SSA) analysis, and kinetics cycling measurements. Ball milling at -40°C showed no appreciable deviations from the 20°C sample, but the -196°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.
Revised: April 7, 2011 |
Published: May 1, 2009
Citation
Osborn W., T. Markmaitree, L.D. Shaw, J.Z. Hu, J. Kwak, and Z. Yang. 2009.Low Temperature Milling of the LiNH2 + LiH Hydrogen Storage System.International Journal of Hydrogen Energy 34, no. 10:4331-4339.PNNL-SA-65424.doi:10.1016/j.ijhydene.2009.03.032