Enhanced dehydrogenation of LiBH4·NH3-LiAlH4 composites

Constructing reactive composite is a feasible approach to promote the dehydrogenation of high-capacity B-/Al-based complex hydrides, such as LiBH4 and LiAlH4. In this work, LiBH4·NH3 was firstly synthesized by exposing LiBH4 to liquefied NH3. In the heating process, the NH3 was released from LiBH4·NH3 instead of reacting with LiBH4. The LiBH4·NH3 was further manually mixed with LiAlH4 at different ratio, and the resultant composites started releasing hydrogen in the range of 90-110 °C, which is due to the reaction between LiAlH4 and NH3. The residual LiBH4 decomposed at ∼400 °C, which is lower than that of pure LiBH4. The total hydrogen desorption amount of the composite reaches up to maximum ∼6.53 wt.%, without NH3 release. The present work shows a new compositing way of complex hydrides for high-capacity hydrogen storage.