Easy up-scaleable approach to improve the properties of metal-alloys for hydrogen storage

Abstract

Methods to increase the heat conductivity and reduce the expansion stress of metal alloys during hydrogen absorption are investigated. The applied approach focuses on strategies, which are time-efficient and can be up-scaled for larger batches of metal alloy. The properties of the commercial available room-temperature metal alloy HydralloyC5 (Ti0.95Zr0.05Mn1.46V0.45Fe0.09) are successfully improved by applying wash-coating techniques. By adding 10 wt.% ENG (expanded natural graphite) or aluminium-powder onto the metal surface prior to hydrogen absorption, the heat conductivity of the samples is improved. Furthermore, the overall expansion stress of the metal alloy during hydrogen absorption is reduced by 20% by adding only small amounts of Aerosil as a glidant agent (0.2 wt.%) to the coating mixture.