Material properties of MBH4 (M=Li,Na,and K)

Fundamental researches on complex hydrides are recently of great importance to develop practical hydrogen storage materials with higher gravimetric hydrogen densities than those of conventional materials. In this preliminary report, we discuss the correlation between B-H atomistic vibrations in [BH4]--anion and melting temperatures of MBH4 (M=Li, Na, and K), on the basis of the experimental results combined the Raman spectroscopy and differential scanning calorimetry. Both the B-H stretching modes ν1 and B-H bending modes ν2, decrease in the order of LiBH4>NaBH4>KBH4, except for ν1 of LiBH4. On the other hand, the melting temperatures under hydrogen atmosphere as an index of hydrogen desorption (decomposition) temperatures decrease in the opposite order