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

Ye, Changchun; Cheng, Hongfei; Zheng, Lirong; Lin, Jiajin; Xu, Qingshuai; Qiu, Yongfu; Pan, Zhenghui; Qiu, Yongcai · Nano Lett · 2023

basic_science · Level V

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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 CoSnO<sub>3-<i>y</i></sub>, 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 (Co<sub>1-<i>x</i></sub>SnO<sub>3-<i>y</i></sub>-Fe<sub>0.021</sub>-A/C) demonstrates excellent oxygen evolution reaction and oxygen reduction reaction activities with a smaller potential gap (Δ<i>E</i> = 0.687 V), and the Zn-air battery based with Co<sub>1-<i>x</i></sub>SnO<sub>3-<i>y</i></sub>-Fe<sub>0.021</sub>-A/C exhibits excellent output power density, cycle performance, and flexibility.