Impact of Ce doping and cold rolling on the activation performance of V₇₀Ti₁₀Cr₂₀ alloy

The study investigated the influence of Ce alloying and cold rolling on the activation behavior of V₇₀Ti₁₀Cr₂₀-based alloys. The activation conditions of single cold rolled (V₇₀Ti₁₀Cr₂₀-0.3) and single Ce replaced (V₇₀Ti₁₀Cr₂₀Ce₁) samples were reduced from the original two heat treatments to one heat treatment, and the incubation time was about 105 min. Unexpectedly, the two modification methods produce excellent synergistic effects that the co-modified sample (V₇₀Ti₁₀Cr₂₀Ce₁-0.5) was activated at room temperature (25°C) without incubation period, and reached saturation capacity (4wt%) within 12 min. Further studies show that CeO₂ formed through Ce doping, serves as an active site for hydrogen absorption, facilitating the passage of hydrogen atoms through the dense oxide layer on the surface of vanadium-based alloys. Upon the foundation of Ce doping, cold rolling leads to the aggregation of dislocations around CeO₂ sites, thereby further establishing a hydrogen diffusion pathway from the surface into the bulk phase, thus significantly improving the activation performance of the alloy. This work establishes a robust basis for the practical engineering use of vanadium-based hydrogen storage alloys.