Dehydrogenation Performances of Different Al Source Composite Systems of 2LiBH4 + M (M = Al, LiAlH4, Li3AlH6)

Abstract

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.

Effect of Different Amounts of TiF3 on the Reversible Hydrogen Storage Properties of 2LiBH4–Li3AlH6 Composite

“…LiBH 4 powder (95% purity) and TiF 3 powder (99% purity) were purchased from Acros Organics and Sigma Aldrich, respectively. Li 3 AlH 6 powder was obtained by mixing LiAlH 4 (95% purity, Sigma Aldrich) and LiH (98% purity, Alfa Aesar) using a highenergy ball-milling method at a ball-to-powder ratio of 40:1 (Li et al, 2020). All the materials used in this work were stored in a glove box purchased from Mikrouna.…”

“…To reveal the dehydrogenation pathway and catalytic effect of TiF 3 , the XRD patterns of the dehydrogenation products of the four samples are displayed in Figure 5. In the 2LiBH 4 -Li 3 AlH 6 composite (Figure 5A), the presence of LiH, Al, and AlB 2 phases indicates that LiBH 4 reacted with Al generated from Li 3 AlH 6 (Li et al, 2020) in situ to form AlB 2 , as shown in Eq. 3 (Choi et al, 2011b;Soru, 2014;Meethom, et al 2020):…”

A Review of High Density Solid Hydrogen Storage Materials by Pyrolysis for Promising Mobile Applications

“…About 9.1 wt % hydrogen was released during its dehydrogenation processes. 56 The onset dehydrogenation temperature of LiBH 4 −LiAlH 4 composites was found to be reduced by 120 °C through quenching the dehydrogenation process. 57 The hydrogen desorption temperature was also demonstrated to be decreased to 250 °C by doping anion-set metal hydrides Mg 2 NiH 4 to LiBH 4 .…”

“…The 2LiBH 4 –Li 3 AlH 6 composites were demonstrated to have better dehydrogenation properties than 2LiBH 4 –LiAlH 4 and 2LiBH 4 –Al composites. About 9.1 wt % hydrogen was released during its dehydrogenation processes . The onset dehydrogenation temperature of LiBH 4 –LiAlH 4 composites was found to be reduced by 120 °C through quenching the dehydrogenation process .…”