Development of RE-based and Ti-based multicomponent metal hydrides with comprehensive properties comparison for fuel cell hydrogen feeding system

Abstract

Metal hydride is an applicable hydrogen storage technology for fuel cell hydrogen feeding system. However, previous investigations mainly focused on the individual rare earth-based or titanium-based systems for other specific applications, and integrated study between these two is basically absent. In this work, AB5-type La–Ce–Ca–Ni-based alloys and AB2-type Ti–Zr–Mn–Cr–V-based alloys were prepared and investigated, from which La0.45Ce0.35Ca0.2Ni5 and Ti0.88Zr0.12Mn1.2Cr0.6V0.2 were selected for further comprehensive properties comparison. In the aspect of reversible capacity, La0.45Ce0.35Ca0.2Ni5 wins the competition in volumetric capacity (126.65 kg H2/m3) with a more efficient capacity utilization of 93.71%, while Ti0.88Zr0.12Mn1.2Cr0.6V0.2 behaves better in gravimetric capacity (1.67 wt% H2). For cycling performances, La0.45Ce0.35Ca0.2Ni5 has an increasing disorder in crystal with a slight capacity deterioration of 3.77%, while other properties maintain favorable stability as Ti0.88Zr0.12Mn1.2Cr0.6V0.2. Additionally, the 64.1% difference in crystallographic anisotropy of Ti0.88Zr0.12Mn1.2Cr0.6V0.2 leads to a more apparent anisotropy in stress–strain resistance, apparent pulverization, the presence of peculiar pomegranate-like structure with an increased specific surface area, and faster mass transfer. Generally, both La0.45Ce0.35Ca0.2Ni5 and Ti0.88Zr0.12Mn1.2Cr0.6V0.2 could be the qualified candidates for hydrogen feeding system.