Rapid Solidified Mg-based Alloys for Hydrogen Storage?;

S. ROZEMBERG; J. LANG; F. SAPORITI; F. AUDEBERT; M. STOICA; J.HUOT

Santa Fe

Congreso; Jornadas SAM - XIII Congreso IBEROMET; 2014

Mg has high technological interest due to its potential application as source for Hydrogen storage. Mg has high hydrogen absorption capacity of 7.6 wt% H. The high temperature required for hydrogen desorption limit its technological applications. To decrease the temperature of desorption, improve the kinetics and stability, with cycles of hydrogen absorption and desorption, the effect of alloy elements such as Cu, Si, Al and rare earth in Mg based alloys produced by rapid solidification were studied. The hydrogen absorption-desorption cycle at 350°C was studied for the following alloys produced by rapid solidification into ribbon form: Mg90Si10, Mg90Cu10, Mg65Cu35, Mg76,5Cu13,5Si10, Mg65Cu25Al10, Mg65Cu25MM10; and Mg65Cu10Al15MM10 (MM: mischmetal). The samples were characterized by X-ray diffraction, differential scanning calorimetry and scanning electron microscopy. It was observed that the Cu and Si alloying elements inactivate the hydrogen absorption capacity of Mg, whereas the partial substitution of Cu by Al and/or MM activates the hydrogen absorption and desorption. A combined partial substitution of Cu by Al and MM highly improve the absorption-desorption reaction kinetic. Results show that this combination of alloying elements can be used as design strategy for new Mg alloys to be used as storage and continuous supply of hydrogen in energy systems, such as fuel cells.