Effects of nano additives on hydrogen storage behavior of the multinary complex hydride LiBH_4/LiNH_2/MgH_2

摘要

Multinary complex hydrides comprised of borohydrides, amides and metal hydrides have been synthesized using the solid state mechano-chemical process. After the optimization of the system, it was found that LiBH_4/LiNH_2/MgH_2 exhibits potential reversible hydrogen storage behavior (>6 wt.%) at temperatures of 125-175 ℃. To further improve the hydrogen performance of the system, various nano additives namely, nickel, cobalt, iron, copper, and manganese were investigated. It was observed that some of these additives (Co, Ni) lowered the hydrogen release temperature at least 75-100 ℃ in the major hydrogen decomposition step. While other additives acted as catalysts and increased the rate at which hydrogen was released. Combinatorial addition of selected materials were also investigated and found to have both a positive effect on kinetics and reduction in hydrogen desorption temperature.