Dehydriding Property of LiBH₄ Combined with Mg₂FeH₆

Abstract

A dehydriding property of xLiBH₄ + (1 − x)Mg₂FeH₆ (x = 0.1–0.83) was investigated. The dehydriding reactions of pure LiBH₄ and Mg₂FeH₆ start at approximately 650 and 450 K, and 12.5 and 4.3 mass% hydrogen are released, respectively. The property drastically changes by combining LiBH₄ and Mg₂FeH₆. Within the composition range 0.1 ≤ x ≤ 0.5, LiBH₄ and Mg₂FeH₆ simultaneously release hydrogen. The reaction temperatures and quantities of released hydrogen alter with x. The lattice parameter of the Mg₂FeH₆ phase measured by in-situ high-resolution synchrotron diffraction measurements suggest the possibility of forming Li_xMg_2−2x(BH₄)_x(FeH₆)_1−x with both double-cation and double-anion.