Carbon‐Stabilized High‐Capacity Ferroferric Oxide Nanorod Array for Flexible Solid‐State Alkaline Battery–Supercapacitor Hybrid Device with High Environmental Suitability |
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Authors: | Ruizhi Li Yimeng Wang Cheng Zhou Chong Wang Xin Ba Yuanyuan Li Xintang Huang Jinping Liu |
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Affiliation: | 1. School of Chemistry, Chemical Engineering and Life Science and State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, Hubei, P. R. China;2. Institute of Nanoscience and Nanotechnology, Department of Physics, Central China Normal University, Wuhan, Hubei, P. R. China;3. School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, P. R. China |
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Abstract: | Iron oxides are promising to be utilized in rechargeable alkaline battery with high capacity upon complete redox reaction (Fe3+ Fe0). However, their practical application has been hampered by the poor structural stability during cycling, presenting a challenge that is particularly huge when binder‐free electrode is employed. This paper proposes a “carbon shell‐protection” solution and reports on a ferroferric oxide–carbon (Fe3O4–C) binder‐free nanorod array anode exhibiting much improved cyclic stability (from only hundreds of times to >5000 times), excellent rate performance, and a high capacity of ≈7776.36 C cm?3 (≈0.4278 C cm?2; 247.5 mAh g?1, 71.4% of the theoretical value) in alkaline electrolyte. Furthermore, by pairing with a capacitive carbon nanotubes (CNTs) film cathode, a unique flexible solid‐state rechargeable alkaline battery‐supercapacitor hybrid device (≈360 μm thickness) is assembled. It delivers high energy and power densities (1.56 mWh cm?3; 0.48 W cm?3/≈4.8 s charging), surpassing many recently reported flexible supercapacitors. The highest energy density value even approaches that of Li thin‐film batteries and is about several times that of the commercial 5.5 V/100 mF supercapacitor. In particular, the hybrid device still maintains good electrochemical attributes in cases of substantially bending, high mechanical pressure, and elevated temperature (up to 80 °C), demonstrating high environmental suitability. |
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Keywords: | carbon‐stabilized Fe3O4 environmental suitability flexible nanorod arrays solid‐state battery– supercapacitor hybrid device |
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