Facile regeneration of lithium borohydride from anhydrous lithium metaborate using magnesium hydride

Abstract

In this work, we report a facile method to regenerate LiBH₄ from its ideal hydrolytic product (LiBO₂) using MgH₂ as the reducing agent under ambient conditions. An outstanding yield of 91.4% could be achieved due to the high reactivity of MgH₂ and grinding efficiency. This method is expected to complete the regeneration and hydrolysis cycle of LiBH₄. The energy efficiency of this cycle is 50.54% based on thermodynamic calculations. Compared with previous methods, this approach does not require high temperatures, high pressure H₂, and expensive boron sources (e.g. NaBH₄, toxic B₂H₆). Furthermore, the regeneration mechanism of LiBH₄ is clarified.