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A Low‐Cost, Self‐Standing NiCo 2 O 4 @CNT/CNT Multilayer Electrode for Flexible Asymmetric Solid‐State Supercapacitors
Author(s) -
Wu Peng,
Cheng Shuang,
Yao Minghai,
Yang Lufeng,
Zhu Yuanyuan,
Liu Peipei,
Xing Ou,
Zhou Jun,
Wang Mengkun,
Luo Haowei,
Liu Meilin
Publication year - 2017
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201702160
Subject(s) - supercapacitor , materials science , electrode , capacitance , carbon nanotube , composite number , fabrication , electrochemistry , nanotechnology , composite material , power density , optoelectronics , power (physics) , chemistry , medicine , alternative medicine , physics , pathology , quantum mechanics
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 NiCo 2 O 4 @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 NiCo 2 O 4 @CNT/CNT film electrodes are fabricated via stacking NiCo 2 O 4 @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.