Coupling rare-earth metal introduction and alkali oxide addition to achieve efficient regeneration of LiBH4 by reacting hydrous LiBO2 with Al

The lack of cost-effective regeneration techniques for LiBH 4 limits its large-scale applications for supplying hydrogen via hydrolysis. Now, we report a facile method to regenerate LiBH 4 by ball milling its real hydrolytic byproduct (LiBO 2 · x H 2 O) with cheap Al based reducing agents, instead of traditional Mg. Effective strategies are developed to promote the formation of LiBH 4 by introducing Li 2 O to enable the dense Al 2 O 3 to convert into LiAlO 2 on Al surface and break up passivation layers, and by partially replacing Al with Al-RE alloy to improve grinding and contacting efficiency of raw materials and facilitate the conversion from initial H + in LiBO 2 ·2H 2 O to final H ¯ in LiBH 4 . A yield of 10.4 % can be obtained for a relatively short ball milling time (10 h) for the Al-Al 2 Ce-Li 2 O-LiBO 2 ·2H 2 O system. Another advantage of this method is that the utilization of H + source in LiBO 2 ·2H 2 O improves energy efficiency and reduces the cost. This work broadens the species of reducing agents for borohydride regeneration and enriches its regeneration methods.