A Stable Bifunctional Catalyst for Rechargeable Zinc–Air Batteries: Iron–Cobalt Nanoparticles Embedded in a Nitrogen‐Doped 3D Carbon Matrix. (12th November 2018)

• Record Type: Journal Article
• Authors: Liu, Xu; Wang, Lei; Yu, Peng; Tian, Chungui; Sun, Fanfei; Ma, Jingyuan; Li, Wei; Fu, Honggang
• Is Part Of: Angewandte Chemie. Volume 130:Number 49(2018)
• Page Start: 16398
• Page End: 16402
• Publication Date: 2018-11-12
• Subjects: CoFe-Legierung -- Graphen -- In-situ-XAS -- Kohlenstoff-Nanoröhren -- Zink-Luft-Batterien; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201809009
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Low‐cost, efficient bifunctional electrocatalysts are needed to mediate the oxygen reduction and oxygen evolution reactions (ORR/OER) in Zn–air batteries. Such catalysts should offer binary active sites and an ability to transfer oxygen‐based species and electrons. A 3D catalyst, composed of nanoparticles of CoFe alloy embedded in N‐doped carbon nanotubes tangled with reduced graphene oxide, was developed, which presents appreciable ORR/OER activity when applied in a Zn–air battery. A high open‐circuit voltage of 1.43 V, a stable discharge voltage of 1.22 V, a high energy efficiency of 60.1 %, and excellent stability after 1 600 cycles at 10 mA cm −2 are demonstrated. An all‐solid‐state battery had an outstanding lifetime and high cell efficiency even upon bending. In situ X‐ray absorption spectroscopy revealed that OOH* and O* intermediates induce variations in the Fe−Fe and Co−Co bond lengths, respectively, suggesting that Fe and Co species are crucial to the ORR/OER processes.