Dehydrogenation Performances of Different Al Source Composite Systems of 2LiBH(4) + M (M = Al, LiAlH(4), Li(3)AlH(6))

Hydrogen has become a promising energy source due to its efficient and renewable properties. Although promising, hydrogen energy has not been in widespread use due to the lack of high-performance materials for hydrogen storage. Previous studies have shown that the addition of Al-based compounds to LiBH(4) can create composites that have good properties for hydrogen storage. In this work, the dehydrogenation performances of different composite systems of 2LiBH(4)+ M (M = Al, LiAlH(4), Li(3)AlH(6)) were investigated. The results show that, under a ball to powder ratio of 25:1 and a rotation speed of 300 rpm, the optimum ball milling time is 50 h for synthesizing Li(3)AlH(6) from LiH and LiAlH(4). The three studied systems destabilized LiBH(4) at relatively low temperatures, and the 2LiBH(4)-Li(3)AlH(6) composite demonstrated excellent behavior. Based on the differential scanning calorimetry results, pure LiBH(4) released hydrogen at 469°C. The dehydrogenation temperature of LiBH(4) is 416°C for 2LiBH(4)-Li(3)AlH(6) versus 435°C for 2LiBH(4)-LiAlH(4) and 445°C for 2LiBH(4)-Al. The 2LiBH(4)-Li(3)AlH(6), 2LiBH(4)-LiAlH(4), and 2LiBH(4)-Al samples released 9.1, 8, and 5.7 wt.% of H(2), respectively. Additionally, the 2LiBH(4)-Li(3)AlH(6) composite released the 9.1 wt.% H(2) within 150 min. An increase in the kinetics was achieved. From the results, it was concluded that 2LiBH(4)-Li(3)AlH(6) exhibits the best dehydrogenation performance. Therefore, the 2LiBH(4)-Li(3)AlH(6) composite is considered a promising hydrogen storage material.