Abstract
Due to its high gravimetric capacity of hydrogen (10.5 wt%), LiAlH(4) has been regarded as a promising material for solid-state hydrogen storage material for onboard usage. However, high decomposition temperature, poor kinetics and irreversibility retard its application. To counter this problem, various weight percentages of BaMnO(3) are introduced into the LiAlH(4) system as an additive in this work. As a result, the starting hydrogen release of LiAlH(4) was reduced to 109-115 °C and the second desorption temperature occurred at around 134-158 °C, much lower than pure LiAlH(4). The isothermal desorption kinetics also proved that faster desorption kinetics can be observed at 90 °C for 80 min. About 2.00-2.60 wt% of H(2) could be desorbed by the composite, whereas only <1.00 wt% of H(2) was desorbed by undoped LiAlH(4). Additionally, adding BaMnO(3) reduced the activation energies by 30 kJ/mol for the first stages and 34 kJ/mol for the second stages. Based on the X-ray diffraction result, the active species formed of MnO(2) and Ba or Ba-containing materials are believed to be responsible for the noticeable enhancement in the desorption properties of LiAlH(4).