Effect of salts addition on the hydrogen generation of Al–LiH composite elaborated by ball milling

• Novel effects of LiH and salts on hydrolysis of Al have been studied.
• KCl proves to be effective in promoting the hydrogen generation.
• LiH plays a more important role in the optimization process.
• LiAl2(OH)7 hydrate is generated and believed to be helpful.

Hydrogen generation from ball milled Al–LiH-salts mixture is studied. Different salts are used to test their effects on the hydrolysis properties of Al–LiH composite. KCl is found to be more effective than other salts and shows the best performance. Raising initial reaction temperature can effectively improve hydrogen yield and HG (hydrogen generation) rate of the Al–LiH–KCl mixture. Optimizing the milling conditions is necessary to improve the hydrogen generation performances of the composites. The addition amounts of KCl and LiH are varied and 10 mol% proves to be the optimum value for both of them in this work. Too much addition of LiH or KCl will cause the decrease of the hydrogen yield. A proper milling time of 10 h is discovered in this work which is beneficial for the decrease of grain size and improvement of reactivity. The 10 h milled Al-10 mol%LiH-10 mol% KCl mixture reaches a hydrogen yield of 97.1% in 10 min at 60 °C. Preliminary mechanism for the improvement has been discussed.