Tailoring Metal–Oxygen Bonds Boosts Oxygen Reaction Kinetics for High-Performance Zinc–Air Batteries

Abstract

Metal–oxygen bonds significantly affect the oxygen reaction kinetics of metal oxide-based catalysts but still face the bottlenecks of limited cognition and insufficient regulation. Herein, we develop a unique strategy to accurately tailor metal–oxygen bond structure via amorphous/crystalline heterojunction realized by ion-exchange. Compared with pristine amorphous CoSnO3–y, iron ion-exchange induced amorphous/crystalline structure strengthens the Sn–O bond, weakens the Co–O bond strength, and introduces additional Fe–O bond, accompanied by abundant cobalt defects and optimal oxygen defects with larger pore structure and specific surface area. The optimization of metal–oxygen bond structure is dominated by the introduction of crystal structure and further promoted by the introduction of Fe–O bond and rich Co defect. Remarkably, the Fe doped amorphous/crystalline catalyst (Co1–xSnO3–y-Fe0.021-A/C) demonstrates excellent oxygen evolution reaction and oxygen reduction reaction activities with a smaller potential gap (ΔE = 0.687 V), and the Zn–air battery based with Co1–xSnO3–y-Fe0.021-A/C exhibits excellent output power density, cycle performance, and flexibility.