真空蒸着法により作製したMg/Fe/Pd積層膜の水素吸蔵・放出特性評価

抄録

Hydrogen storage alloys that can store and transport hydrogen with high density and safety are attracting attention as one of the hydrogen storage methods. Among the various hydrogen storage alloys, the Mg system has a high hydrogen storage capacity, but there is a problem that the reaction temperature with hydrogen is relatively high. In this research, we focused on thinning and laminating Mg, Fe, and Pd to improve the hydrogen storage / release characteristics for the films of Mg-based hydrogen storage. Mg/Fe/Pd thin films are fabricated by resistance heating method (RH) and pulsed laser deposition (PLD) method, which are two kinds of vacuum deposition method, and then their hydrogen storage / release characteristics are evaluated. We treated them to activation and hydrogenation for the films and then conducted X-ray diffraction (XRD) analyses, differential scanning calorimetries (DSC), and Pressure-Composition-Temperature (PCT) measurements to investigate the hydrogenation, hydrogen release temperature, and hydrogen storage capacity of the sample. All samples were hydrogenated and the hydrogen release temperature improved by 180-280 °C down, and the hydrogen storage was 4.50-5.58 wt.% for the Mg/Fe/Pd films made with RH and 1.33-2.90 wt.% for the Mg/Fe/Mg/Fe/Pd films made with PLD. This results show that it might be possible the hydrogenated Mg layer prevent the permeation of hydrogen to the second layer.