Performance and fuel cell applications of reacted ball-milled MgH 2 /5.3 wt% TiH 2 nanocomposite powders

• Published in: RSC advances 2018-11, Vol.8 (67), p.38175-38185
• Main Authors: El-Eskandarany, Mohamed Sherif, Alkandary, Abdullah, Aldakheel, Fahad, Al-Saidi, Mariam, Al-Ajmi, Fahad, Banyan, Mohammad
• Format: Article
• Language: English
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/c8ra06570e

The present study aimed to enhance the kinetics behavior and destabilize the thermal stability of MgH powder by high-energy milling of Mg powder under 50 bar of H for several hours using Ti-balls as the milling media. The results showed a monotonical increase in Ti content worn off the milling media and introduced into the milled powders. This gradual doping led to homogeneous distribution of fine Ti particles into the Mg/MgH powder matrix without agglomeration or compositional fluctuations at the micro-level. During the activation stage of the powders, achieved at 350 °C/35 bar H prior to hydrogenation kinetics measurements, elemental Ti reacted with H to form fine TiH particles. Our proposed mechanically induced catalyzation approach was found to be mutually beneficial for decreasing the apparent activation energy of decomposition. In addition, introducing 5.3 wt% of TiH to the MgH powder obtained after 50 h led to the achievement of superior enhancement of gas uptake/release kinetics at relatively low temperatures. The nanocomposite MgH /5.3 TiH powder possessed fast hydrogenation/dehydrogenation kinetics behaviors and revealed long cycle lifetimes. This system was successfully employed as a solid-state hydrogen source to charge the battery of a cell-phone device using an integrated Ti-tank/commercial proton exchange membrane-fuel cell system.