A Low‐Cost,Self‐Standing NiCo2O4@CNT/CNT Multilayer Electrode for Flexible Asymmetric Solid‐State Supercapacitors |
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Authors: | Peng Wu Shuang Cheng Minghai Yao Lufeng Yang Yuanyuan Zhu Peipei Liu Ou Xing Jun Zhou Mengkun Wang Haowei Luo Meilin Liu |
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Affiliation: | 1. Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou, P. R. China;2. School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, USA |
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Abstract: | The demand for a new generation of flexible, portable, and high‐capacity power sources increases rapidly with the development of advanced wearable electronic devices. Here we report a simple process for large‐scale fabrication of self‐standing composite film electrodes composed of NiCo2O4@carbon nanotube (CNT) for supercapacitors. Among all composite electrodes prepared, the one fired in air displays the best electrochemical behavior, achieving a specific capacitance of 1,590 F g?1 at 0.5 A g?1 while maintaining excellent stability. The NiCo2O4@CNT/CNT film electrodes are fabricated via stacking NiCo2O4@CNT and CNT alternately through vacuum filtration. Lightweight, flexible, and self‐standing film electrodes (≈24.3 µm thick) exhibit high volumetric capacitance of 873 F cm?3 (with an areal mass of 2.5 mg cm?2) at 0.5 A g?1. An all‐solid‐state asymmetric supercapacitor consists of a composite film electrode and a treated carbon cloth electrode has not only high energy density (≈27.6 Wh kg?1) at 0.55 kW kg?1 (including the weight of the two electrodes) but also excellent cycling stability (retaining ≈95% of the initial capacitance after 5000 cycles), demonstrating the potential for practical application in wearable devices. |
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Keywords: | supercapacitors all‐solid‐state supercapacitors asymmetric supercapacitors flexible and self‐standing films NiCo2O4@CNT composites |
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