Tunable Ce‐Doping Engineering in TiFe‐Based Alloys for High‐Activation and High‐Durability Hydrogen Storage

TiFe‐based hydrogen storage alloys have garnered significant attention because of their cost‐effectiveness, high hydrogen capacity, and favorable hydrogen absorption/desorption characteristics. However, practical application was limited by activation challenges and sensitivity to environmental poisoning. This study explores a highly effective engineering strategy to overcome these limitations by incorporating excess Ti with tunable Ce doping in TiFe‐based alloys. Such engineered Ti 1‐ x Ce x Fe 0.75 Mn 0.06 Co 0.06 ( x = 0, 0.02, 0.04, 0.06) alloys, by virtue of doping Ce for excess Ti, can significantly improve activation at room temperature while maintaining high hydrogen storage capacity. Notably, the alloy with x = 0.04 achieves a peak hydrogen storage capacity of 1.94 wt% and an effective capacity of 1.85 wt%, highlighting the remarkably enhanced storage potential. We additionally verify Ce doping can effectively improve its cyclic durability for hydrogen storage, reducing capacity attenuation from 14.21% to 2.06%. The residual hydrogen storage capacity—a key factor for efficient desorption—decreased from 0.172 wt% to as low as 0.036 wt%, indicating enhanced desorption efficiency. Furthermore, this study reveals a gradual shift in the activation mechanism—from an initial reliance on excess Ti to a Ce‐driven process—marking a transformative step in alloy design for reliable hydrogen storage applications.