Effect of activation procedure on Sm-Co-Fe-Zr-B compound for low temperature efficient hydrogen storage

Abstract

The present research work is focused on the effect of activation procedure on the hydrogen absorption-desorption properties of new rare earth transition metal compound based on Sm(Co0.6Fe0.2Zr0.16B0.04)7.5 composition. Crystal structure and composition is always connected to the maximum capacity of the intermetallic hydrides. For composite materials the thermodynamic properties of hydrogenation & dehydrogenation procedure are mostly explained through microstructure-microchemistry characteristics. Efficient hydrogen storage is direct connected to the desorbed hydrogen amount. The as hydrogenated material Sm(Co0.6Fe0.2Zr0.16B0.04)7.5 seems to have in the desorption a pressure plateau below the atmospheric pressure at room temperature while the absorbed hydrogen almost remains in the material having capacity of ~0.8 wt. % at 0.1 MPa - 30 oC. After the proper activation procedure, the hydrogenated material desorbs very high amount of hydrogen ~1.9 wt. % at 0.1 MPa - 100 oC. Subsequently, the treatment of the composite materials before hydrogenation & dehydrogenation procedures could play a crucial role on the efficiency.