Role of Li 2 B 12 H 12 for the Formation and Decomposition of LiBH 4

By in situ X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) spectroscopy, the role of Li 2 B 12 H 12 for the sorption of LiBH 4 is analyzed. We demonstrate that Li 2 B 12 H 12 and an amorphous Li 2 B 10 H 10 phase are formed by the reaction of LiBH 4 with diborane (B 2 H 6 ) at 200 °C. Based on our present results, we propose that the Li 2 B 12 H 12 formation in the desorption of LiBH 4 can be explained as a result of reaction of diborane and LiBH 4 . This reaction of the borohydride with diborane may also be observed for other borohydrides, where B 12 H 12 phases are found during decomposition.