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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Mater. | doi: 10.3389/fmats.2019.00261

Hierarchical Hollow Co/N-C@NiCo2O4 Microsphere as Efficient Bi-Functional Electrocatalyst for Rechargeable Zn-Air Battery

Yuke Song1, Wenfu Xie1, Shijin Li1, Jian Guo1* and  Mingfei Shao1*
  • 1State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, China

Zn–air batteries (ZABs) are one of the promising power sources for portable and wearable electronic devices because of their high theoretical specific energy density and low cost. However, their practical performance with high energy density and power density is difficult to maintain under high mass-loading due to the compact restacking that seriously hinders mass/charge diffusion. Herein, we reported an efficient bi-functional electrocatalyst of Ni-Co mixed metal oxides incorporated cobalt/nitrogen doped carbon with hierarchical hollow nanostructure (H-Co/N-C@NiCo2O4). Benefiting from this structural and compositional merits, the as-synthesized H-Co/N-C@NiCo2O4 exhibits excellent electrocatalytic activity and long-term stability for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The potential gap between half-wave potential in ORR and overpotential at a current density of 10 mA cm−2 in OER reaches within 0.8 V, much smaller than that of most reported bi-functional electrocatalysts. Moreover, H-Co/N-C@NiCo2O4 is constructed as an air electrode for rechargeable ZAB, delivering a high power density and long cycling stability. A good linear relationship has been achieved between the power density and various mass-loading of H-Co/N-C@NiCo2O4 on the electrode, indicating well preserved performance even under high dense packing of catalysts, which provides a promising paradigm for the practical applications in ZAB.

Keywords: Bi-functional electrocatalyst, ORR and OER, Synergetic effect, hierarchical hollow nanostructure, Zinc-air battery

Received: 18 Aug 2019; Accepted: 01 Oct 2019.

Copyright: © 2019 Song, Xie, Li, Guo and Shao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
Mx. Jian Guo, State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, China, guojian@mail.buct.edu.cn
Prof. Mingfei Shao, State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, China, shaomf@mail.buct.edu.cn