The antagonism between strength and resistance to hydrogen embrittlement in metallic materials is an intrinsic obstacle to the design of lightweight yet reliable structural components operated in hydrogen-containing environments. Economical and scalable microstructural solutions to this challenge must be found. Here, we introduce a counterintuitive strategy to exploit the typically undesired chemical heterogeneity within the material’s microstructure that enables local enhancement of crack resistance and local hydrogen trapping. We use this approach in a manganese-containing high-strength steel and produce a high dispersion of manganese-rich zones within the microstructure. These solute-rich buffer regions allow for local micro-tuning of the phase stability, arresting hydrogen-induced microcracks and thus interrupting the percolation of hydrogen-assisted damage. This results in a superior hydrogen embrittlement resistance (better by a factor of two) without sacrificing the material’s strength and ductility. The strategy of exploiting chemical heterogeneities, rather than avoiding them, broadens the horizon for microstructure engineering via advanced thermomechanical processing.

Recently, high entropy alloys (HEAs) with body-centred cubic (BCC) single phase structures have attracted wide attention in many fields including hydrogen storage, due to their unique structural characteristics and excellent performance. Its novel design concept provides more possibilities for the investigation of advanced hydrogen storage materials, in which several remarkable research works have been published, providing opportunities for the design of hydrogen storage materials with unprecedented properties. In this review, we combed through the definition and criteria of high entropy alloys, and summarized the current research status of body-centred cubic-structured high entropy alloys for hydrogen storage from multiple perspectives of composition designs, synthesis processes, and hydrogen storage properties. Moreover, the possible application scenarios and future research directions are analysed.