First principles investigation of transition metal hydrides LiXH3 (X = Ti, Mn, and Cu) for hydrogen storage

Renewable energy prices are decreasing, making it easier to make energy systems that are good for the environment. High-density storage for renewable energy is possible with hydrogen. This work focuses on the theoretical study of LiXH₃ (where X = Ti, Mn, and Cu), including their structural, electronic, mechanical, thermoelectric, and hydrogen storage properties, using first-principles calculations. LiCuH₃ is more stable than LiMnH₃ and LiTiH₃, based on the optimization graph. The electronic properties show the metallic nature of these studied hydrides. Born’s criterion indicates that all studied hydrides are brittle for various mechanical applications. LiTiH₃, LiMnH₃, and LiCuH₃ are all thought to be able to store hydrogen with gravimetric storage capacities of 5.22%, 4.66%, and 4.11%, respectively. Based on how their thermoelectric properties change with temperature, all the materials under study can absorb heat energy, which shows that they are both electrically and thermally conductive.