Superior Destabilization Effects of MnF2 over MnCl2 in the Decomposition of LiBH4

A 3LiBH 4 /MnF 2 composite was prepared by mechanically milling a mixture of LiBH 4 and MnF 2 . The decomposition properties of the 3LiBH 4 /MnF 2 composite were investigated and compared with those of the 3LiBH 4 /MnCl 2 composite. Differing from the case for the 3LiBH 4 /MnCl 2 composite where only cation substitution occurs, both the cation substitution of Mn 2+ for Li + and the anion substitution of F – for H – occur in the 3LiBH 4 /MnF 2 composite. Moreover, compared to the 3LiBH 4 /MnCl 2 composite, the 3LiBH 4 /MnF 2 composite has a lower decomposition temperature, a higher purity of evolved hydrogen, and faster decomposition kinetics. These results suggest that MnF 2 has superior destabilization effects over MnCl 2 in the decomposition of LiBH 4, which can be attributed to the reduced stability of B–H bonds by partial anion substitution of the F – for the H – .