Synergetic Heterophase and Selective Defect Engineering of Nano Multicomponent Alloys for Rechargeable Zn–Air Batteries

ABSTRACT Multicomponent alloys (MCAs) have garnered significant attention in electrocatalytic applications due to their tunable multielement composition, electronic structure, and excellent stability. However, the homogeneity of MCAs results in the potential lack of distinctive catalytic sites and surface sites. This work demonstrates an MCA's design strategy and structural evolution process combining heterophase and selective defect engineering. Preferential dealloying in the bcc phase with lower ORR activity is achieved by taking advantage of the atomic arrangement structural difference of the heterophase, thus obtaining an fcc/bcc with defects ( bcc‐d ) MCA encapsulated in the carbon nanotubes (HFeCoCuAl@CNTs). The formed vacancies in the bcc‐d generate the unsaturated coordination of adjacent Fe/Co active sites and optimize the electronic structure. The synergistic catalysis of the fcc / bcc‐d accelerates all steps of the 4e ⁻ ORR. Therefore, HFeCoCuAl@CNTs exhibits the excellent electrocatalytic activity and stability in ORR (half‐wave potential: 0.823 V) and OER ( E _j=10 : 344 mV) under alkaline conditions. Using the commercial Pt/C as a comparison, the HFeCoCuAl@CNTs‐based zinc–air batteries deliver the higher specific capacity of 814 mAh g _Zn ⁻¹ , power density of 144.8 mW cm ⁻² , and long‐term stability exceeding 780 h. These findings provide unique ideas for designing MCA electrocatalysts suitable for high‐performance zinc–air batteries.