CaNi5-based alloys and nanoconfined NaAlH4 for solid-state hydrogen storage

Abstract

A simple mechanical ball-milling and annealing has been used to synthesize CaNi5-based alloys. Heat treatment at 800 ºC under vacuum results in the formation of a crystalline CaNi5 phase. CaNi4.9Al0.1 shows durability improvement by maintaining its initial hydrogen absorption capacity for 20 cycles performed at 85 ºC. NaAlH4 was confined within 2-3 nm pores in a carbon scaffold and shows significant improvement in the hydrogen desorption kinetics and thermodynamic properties compared to bulk NaAlH4.