Interface and body engineering via aluminum hydride enabling Ti-V-Cr-Mn alloy with enhanced hydrogen storage performance

The theoretical hydrogen storage capacity of V-based solid solution materials can reach 3.8 wt%, but the hydrogen in VH hydride is difficult to release at ambient temperature and pressure, so addressing the issue of hydrogen release under mild conditions is essential. While AlH₃ has high weight hydrogen storage density (10.1 wt%) and relatively mild hydrogen desorption temperature (≤150 °C). Therefore, using V-based solid solution as the main body, two kinds of hydrogen storage materials are synthesized into a new composite, which can obviously display enhanced hydrogen storage performance. In this work, the structural stability, kinetic and thermodynamic properties of TiV_1.1Cr_0.3Mn_0.6 + x AlH₃ (x = 0, 1, 3, 5, wt.%) composites are studied by means of density functional theory (DFT) calculation and experiment. The results show that the AlH₃-doped composites have Al phase existed in the material via the way of embedding, which improves the hydrogen storage performance and activation property of V-base solid solution. With increasing AlH₃ content, the activation energies (E_a) gradually decrease. The corresponding relationship between the theoretical calculation and the experimental results can provide reference for the subsequent screening of appropriate hydrogen storage materials with application prospect.