Hetero‐Diatomic CoN4‐NiN4 Site Pairs with Long‐Range Coupling as Efficient Bifunctional Catalyst for Rechargeable Zn–Air Batteries

• Published in: Advanced science Vol. 11; no. 22; pp. e2310231 - n/a
• Main Authors: Yang, Yue, Li, Bin, Liang, Yining, Ni, Wenpeng, Li, Xuan, Shen, Gengzhe, Xu, Lin, Chen, Zhengjian, Zhu, Chun, Liang, Jin‐Xia, Zhang, Shiguo
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01.06.2024; John Wiley and Sons Inc; Wiley
• Subjects: Carbon; density functional theory; diatomic catalyst; Nitrogen; oxygen evolution reaction; oxygen reduction reaction; R&D; rechargeable Zn–air batteries; Research & development; Scanning electron microscopy
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202310231

In this study, Co/Ni‐NC catalyst with hetero‐diatomic Co/Ni active sites dispersed on nitrogen‐doped carbon matrix is synthesized via the controlled pyrolysis of ZIF‐8 containing Co2+ and Ni2+ compounds. Experimental characterizations and theoretical calculations reveal that Co and Ni are atomically and uniformly dispersed in pairs of CoN4‐NiN4 with an intersite distance ≈0.41 nm, and there is long‐range d–d coupling between Co and Ni with more electron delocalization for higher bifunctional activity. Besides, the in situ grown carbon nanotubes at the edges of the catalyst particles allow high electronic conductivity for electrocatalysis process. Electrochemical evaluations demonstrate the superior ORR and OER bifunctionality of Co/Ni‐NC catalyst with a narrow potential gap of only 0.691 V and long‐term durability, significantly prevailing over the single‐atom Co‐NC and Ni‐NC catalysts and the benchmark Pt/C and RuO2 catalysts. Co/Ni‐NC catalyzed Zn–air batteries achieve a high specific capacity of 771 mAh g−1 and a long continuous operation period up to 340 h with a small voltage gap of ≈0.65 V, also much superior to Pt/C‐RuO2. CoN4‐NiN4 site pairs with long‐range coupling are atomically dispersed on nitrogen‐doped carbon matrix, and the resultant catalyst is found to show excellent ORR/OER bi‐functionality and used as cathode catalyst for high‐performance rechargeable Zn–air battery.