Characterization of Hydrogen Storage Capabilities in Advanced Battery Materials

Hydrogen storage capabilities in LaNi5 intermetallic compounds have been investigated utilizing the combination of thermoelectric power, Leco hydrogen determination, and Magnetic susceptibility measurements. Thermoelectric power has demonstrated a rapid hydrogen assessment capability and can achieve the equivalent of the pressure-composition-temperature (activity) diagram. Effective use of hydrogen storage materials occurs in the (alpha + beta)-phase plateau region of the PCT diagram. A thorough assessment of the content of each phase in this two-phase region to optimize performance of the hydrogen storage materials has been described. Electron concentration changes with variations in stored hydrogen content, thus altering the filling of the electronic d-band and slope of the plot of the paramagnetic susceptibility as a function of the thermoelectric power coefficient. Practices using the combination of these analytical techniques for rapid characterization of advanced hydrogen storage materials have been discussed. These methods also provide an opportunity for sensor development to monitor the hydrogen content in different materials.