Solid State Hydrogen Storage Materials for Application to Energy Needs.

摘要

Six areas of study of solid state hydrogen storage materials were completed in the two and one half year study. These were (1) literature survey and field trips relating to studies of hydrogen storage materials, (2) safety characteristics of LaNi5 hydrides, (3) general hydriding characteristics of LaNi5, (4) study of kinetics of hydrogen desorption of LaNi5, (5) studies of new alloy systems, and (6) development of fundamental insights of hydriding and of predictive criteria for new and improved hydrides. The safety characteristics of LaNi5 were fully evaluated in terms of the properties of powders. Bulk powder properties determined were: ignition temperature, relative combustibility, flammability, shock sensitivity, impact sensitivity, spark sensitivity, and explosibility. Studies of dispersed dust clouds were conducted in which ignition temperature, minimum ignition energy, minimum explosive concentration, maximum explosive pressure, and maximum rate of pressure rise were determined. From these data, an index of explosibility was obtained, which indicated a 'weak' rating. The general hydriding characteristics included data on activation, effects of repetitive cycling, hysteresis effects, surface poisoning effects, and more precise pressure-temperature-composition relationships of the system than have been available in the literature. The kinetics of hydrogen desorption from LaNi5 hydride were established. The order, rate constant, and activation energy were determined. The effects of surface contamination were studed by exposure to air, oxygen, and moisture. Evaluation was conducte principally by the change in the kinetics of desorption of hydrogen.