Characterization of AB5 alloys for hydrogen storage applications at low temperatures

GENTILE M. A.; MEYER G. O.; BORZONE E.; BARUJ A.

Gramados

Conferencia; XVI Brazilian MRS Meeting; 2017

Brazilian Materials Research Society

We present the characterization of the reaction of some AB5 alloys with hydrogen in the extended temperature range from -30 °C to 40°C. The studies were performed as part of a project which goal is the design of hydrogen storage devices for using them as hydrogen sources in the mountains, with operation temperature down to -20°C. At this lower operation temperature, the device should provide hydrogen at a pressure higher than 1.2 bar.In this sense, alloys with general composition MmyLa1-yNi5-xSnx where prepared by arc melting, with a subsequent thermal treatment for homogenization and a surface treatment for facilitating their activation under hydrogen atmosphere.The equilibrium properties of the reaction of these alloys with hydrogen were measured using the direct vant Hoff technique, obtaining the equilibrium pressure-temperature relationship and entropy and enthalpy changes involved.Absorption and desorption kinetics at different temperatures are also presented.Finally, a summary of all these properties is used to compared between them and the goals of a specific technological application.