Tailor-designed vanadium alloys for hydrogen storage in remote area and movable power supply systems

Abstract

Vanadium-based alloys are potential materials for hydrogen storage applications in Remote Area Power Supply (RAPS) and Movable Power Supply (MPS). In this study, V80Ti8Cr12 alloys are tailor-made to meet the RAPS and MPS working conditions (293–323 K and 0.2–2 MPa). The effects of pulverization methods and particle sizes on the alloy's hydrogen storage properties have been systematically investigated. In addition, a novel Pressure-Composition-Isotherm approach is employed for the first time to accurately evaluate the hydrogen storage capacities. The reduction of particle size enhances the absorption kinetics due to the increased surface area. However, mechanical pulverization causes lattice distortion that decreases the hydrogen absorption capacity and desorption rate. In contrast, hydrogen embrittlement can effectively pulverize the alloys without generating lattice distortion. The results reveal that 5 mm sample, which is simply subjected to hydrogen embrittlement, achieves the largest usable hydrogen storage capacity up to 2.1 wt% and the fastest hydrogen desorption rate of ∼4 sccm/g that is nine times quicker than required for RAPS and MPS applications. After 500 cycles, the 5 mm alloy retains 90 % of its capacity, demonstrating excellent durability. Hence, 5 mm hydrogen-embrittled V80Ti8Cr12 alloy is an ideal hydrogen storage material in RAPS and MPS systems.