Enhancement of the Desorption Properties of LiAlH(4) by the Addition of LaCoO(3)

The high hydrogen storage capacity (10.5 wt.%) and release of hydrogen at a moderate temperature make LiAlH(4) an appealing material for hydrogen storage. However, LiAlH(4) suffers from slow kinetics and irreversibility. Hence, LaCoO(3) was selected as an additive to defeat the slow kinetics problems of LiAlH(4). For the irreversibility part, it still required high pressure to absorb hydrogen. Thus, this study focused on the reduction of the onset desorption temperature and the quickening of the desorption kinetics of LiAlH(4). Here, we report the different weight percentages of LaCoO(3) mixed with LiAlH(4) using the ball-milling method. Interestingly, the addition of 10 wt.% of LaCoO(3) resulted in a decrease in the desorption temperature to 70 °C for the first stage and 156 °C for the second stage. In addition, at 90 °C, LiAlH(4) + 10 wt.% LaCoO(3) can desorb 3.37 wt.% of H(2) in 80 min, which is 10 times faster than the unsubstituted samples. The activation energies values for this composite are greatly reduced to 71 kJ/mol for the first stages and 95 kJ/mol for the second stages compared to milled LiAlH(4) (107 kJ/mol and 120 kJ/mol for the first two stages, respectively). The enhancement of hydrogen desorption kinetics of LiAlH(4) is attributed to the in situ formation of AlCo and La or La-containing species in the presence of LaCoO(3), which resulted in a reduction of the onset desorption temperature and activation energies of LiAlH(4).