Enhanced hydrogen storage properties of LiBH4 generated using a porous Li3BO3 catalyst

Abstract

LiBH4 is considered a promising hydrogen storage material for automotive applications; however, its usage is limited because of unfavorable reversibility and sluggish kinetics. In this paper, we have improved the hydrogen storage properties of LiBH4 by doping with a porous Li3BO3 additive, which was prepared by a solid state synthesis method. The LiBH4–33 wt% Li3BO3 composite was prepared via mechanical milling. The composite exhibited an acceptable hydrogenation/dehydrogenation rate, high hydrogen storage capacity and superior reversibility. The initial dehydrogenation temperature of the composite was 105 °C, which is 205 °C lower than that of the pristine LiBH4, and the hydrogen desorption capacity was 4.12 wt% at 450 °C within 2000 s. The composite maintained its hydrogen absorption capacity of 2.8 wt% with a narrow gap after 5 de/hydrogenation cycles at 400 °C and 5.0 MPa. The Li3BO3 additive clearly enhanced the hydrogen storage properties of LiBH4 and facilitated the decomposition and formation of [BH4]−, thus accelerating de/rehydrogenation of LiBH4. At the same time, Li3BO3 offered numerous porous channels that enhanced hydrogen circulation.