Interpenetrating Triphase Cobalt‐Based Nanocomposites as Efficient Bifunctional Oxygen Electrocatalysts for Long‐Lasting Rechargeable Zn–Air Batteries |
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| Authors: | Yi Jiang Ya‐Ping Deng Jing Fu Dong Un Lee Ruilin Liang Zachary Paul Cano Yangshuai Liu Zhengyu Bai Sooyeon Hwang Lin Yang Dong Su Weiguo Chu Zhongwei Chen |
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| Institution: | 1. CAS Key Laboratory for Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, P. R. China;2. University of Chinese Academy of Sciences, Beijing, P. R. China;3. Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute for Sustainable Energy, University of Waterloo, Waterloo, Ontario, Canada;4. School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, China;5. Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, USA |
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| Abstract: | Rational construction of atomic‐scale interfaces in multiphase nanocomposites is an intriguing and challenging approach to developing advanced catalysts for both oxygen reduction (ORR) and evolution reactions (OER). Herein, a hybrid of interpenetrating metallic Co and spinel Co3O4 “Janus” nanoparticles stitched in porous graphitized shells (Co/Co3O4@PGS) is synthesized via ionic exchange and redox between Co2+ and 2D metal–organic‐framework nanosheets. This strategy is proven to effectively establish highways for the transfer of electrons and reactants within the hybrid through interfacial engineering. Specifically, the phase interpenetration of mixed Co species and encapsulating porous graphitized shells provides an optimal charge/mass transport environment. Furthermore, the defect‐rich interfaces act as atomic‐traps to achieve exceptional adsorption capability for oxygen reactants. Finally, robust coupling between Co and N through intimate covalent bonds prohibits the detachment of nanoparticles. As a result, Co/Co3O4@PGS outperforms state‐of‐the‐art noble‐metal catalysts with a positive half‐wave potential of 0.89 V for ORR and a low potential of 1.58 V at 10 mA cm?2 for OER. In a practical demonstration, ultrastable cyclability with a record lifetime of over 800 h at 10 mA cm?2 is achieved by Zn–air batteries with Co/Co3O4@PGS within the rechargeable air electrode. |
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| Keywords: | bifunctional electrocatalysts interpenetrating phases metal– organic frameworks Zn– air batteries |
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