Synergistic enhancement of hydrogen storage thermodynamic and kinetic performances in Mg–La–Ce alloys via Ti particle doping

Rare-earth magnesium-based hydrogen storage alloys suffer from the slowly dehydrogenation rates and overly stable thermodynamic properties. Synergistic optimization through alloying and doping is an effective way to improve the hydrogen storage performance. In this study, we explore the preparation of Mg₇₀La₂₅Ce₅-based alloy using vacuum melting method and the doping of Ti particles by high-energy mechanical wet ball milling to improve the hydrogen storage performance of the alloy. The results showed that after doping with Ti particles, the roughness of the samples increased, the cracks enlarged, and the surface became more irregular, in which the Mg₇₀La₂₅Ce₅ + 5 wt% Ti swelled and pulverized after de-/hydrogenation activation, and the surface shows large cracked web-like morphology, it can achieve 90% hydrogenation in 20 min at 250 °C and release 3.93 wt% of H₂ in 40 min, and the initial dehydrogenation temperature was reduced; the thermodynamic properties of material effectively improved. Furthermore, the transformation process of MgH₂ and the stable presence of surrounding hydrides during dehydrogenation were investigated through in situ TEM analysis, providing deeper insights into the hydrogen storage mechanism.