Superior Reversible Hydrogen Storage Properties and Mechanism of LiBH4–MgH2–Al Doped with NbF5Additive

Abstract

LiBH4 is one of the most potential candidates for hydrogen storage materials among several sorts of complex borohydrides. Utilizing reactive hydride composites on LiBH4 could destabilize the thermodynamics and improve dehydrogenation behaviors, such as the excellent reversibility of LiBH4–MgH2 and the fast dehydrogenation of LiBH4–Al. The strategy of combining both outstanding effects of MgH2 and Al to form LiBH4–MgH2–Al system has been proposed. However, reduction of hydrogen capacity during cycles has not been solved for the LiBH4–MgH2–Al system, which is considered as the principal problem. In this work, we investigated the reversible hydrogen storage performance and reaction mechanism of LiBH4–MgH2–Al doped with/without NbF5 additive. It can be found that the dehydrogenation of 4LiBH4–MgH2–Al can release about 9.0 wt % H2 quickly without incubation period, compared with 2LiBH4–MgH2. Moreover, it is the first time to achieve completely reversible hydrogen desorption property of LiBH4–MgH2–Al by doping ...