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

Abstract

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 TiV1.1Cr0.3Mn0.6 + 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 (Ea) gradually decrease. The corresponding relationship between the theoreticalcalculation and the experimental results can provide reference for the subsequent screening of appropriate hydrogen storage materials with application prospect.