Synergistic hydrogen generation from AlLi alloy and solid-state NaBH ₄ activated by CoCl ₂ in water for portable fuel cell

Solid-state AlLi/NaBH ₄ mixture activated by CoCl ₂ salt is fabricated for hydrogen generation via a milling process, providing uniform dispersion of AlLi alloy and CoCl ₂ salt among pulverized NaBH ₄ particles in order to improve NaBH ₄ hydrolysis through the contact of NaBH ₄ with active catalytic sites. The active catalytic sites come from Co ₂B loaded in Al(OH) ₃ (Bayerite) or LiAl ₂(OH) ₇ hydrate, generated from the reaction of CoCl ₂, AlLi alloy, and NaBH ₄ in water. The results show that the gravimetric hydrogen storage capacity is as high as 6.4 wt.% and an efficiency of above 90% in 30-min hydrolysis at 323 K could be achieved using the limited amount of water. The hydrogen generation amount and rate could be regulated by changing the composition, mixing style, mixture/water weight ratio, and hydrolysis temperature. The relative mechanism is explored.