An Iron‐Decorated Carbon Aerogel for Rechargeable Flow and Flexible Zn–Air Batteries

• DOI: 10.1002/adma.202002292
• Publication Date: 2020-07-02T05:44:11Z
• Authors: Kunze Wu; Lei Zhang; Yifei Yuan; Linxin Zhong; Zhongxin Chen; Xiao Chi; Hao Lu; Zehong Chen; Ren Zou; Tingzhen Li; Chengyu Jiang; Yongkang Chen; Xinwen Peng; Jun Lu
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

AbstractMechanically stable and foldable air cathodes with exceptional oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activities are key components of wearable metal–air batteries. Herein, a directional freeze‐casting and annealing approach is reported for the construction of a 3D honeycomb nanostructured, N,P‐doped carbon aerogel incorporating in situ grown FeP/Fe2O3 nanoparticles as the cathode in a flexible Zn–air battery (ZAB). The aqueous rechargeable Zn–air batteries assembled with this carbon aerogel exhibit a remarkable specific capacity of 648 mAh g−1 at a current density of 20 mA cm−2 with a good long‐term durability, outperforming those assembled with commercial Pt/C+RuO2 catalyst. Furthermore, such a foldable carbon aerogel with directional channels can serve as a freestanding air cathode for flexible solid‐state Zn–air batteries without the use of carbon paper/cloth and additives, giving a specific capacity of 676 mAh g−1 and an energy density of 517 Wh kg−1 at 5 mA cm−2 together with good cycling stability. This work offers a new strategy to design and synthesize highly effective bifunctional air cathodes to be applied in electrochemical energy devices.