Ce-doped V-Ti-Cr-Fe alloy powder prepared by electrode induction molten gas atomization (EIGA) process for hydrogen storage

High performance and scale production are necessary conditions for the practical application of V-based hydrogen storage alloys. However, traditional preparation methods still suffer from the problem of high melting points of alloys and the tendency to react with crucibles to produce impurities. Therefore, developing a scale preparation method for V-based hydrogen storage alloys with high sphericity, uniform size, and uniform composition remains a huge challenge. This work developed a novel strategy for preparing spherical micrometer V-based alloy powders with high sphericity, uniform size and uniform distribution of CeO_x nanoparticles by the electrode induction molten gas atomization (EIGA) process, and successfully prepares V₇₁Ti₁₀Cr₁₇Fe₂–1.5 wt% Ce alloy powders with particle sizes ranging from <53 μm, 53–106 μm, 106–150 μm, and > 150 μm. It is worth noting that as the particle size of the powder decreases, the hydrogen storage performance of the alloy powder gradually improves. V₇₁Ti₁₀Cr₁₇Fe₂–1.5 wt% Ce (< 53 μm) can achieve optimal hydrogen storage capacity without activation compare with the conventional counterpart. The hydrogen ab/de-sorption capacities can reach 3.56 and 2.40 wt% H₂, respectively. Due to the multi reaction interface interaction formed by uniformly distributed CeO_x nanoparticles, the hydrogen ab/de-sorption activation energy of V₇₁Ti₁₀Cr₁₇Fe₂–1.5 wt% Ce (< 53 μm) is reduced to an astonishing 45.1/20.8 kJ mol⁻¹ H₂. The ab/de-sorption enthalpy of hydrogen sharply decreased to −7.9/16.0 kJ mol⁻¹ H₂. This work provides new insights for the development of high-performance V-based hydrogen storage materials and the scale production of solid-state hydrogen storage materials.