Layer-by-layer self-assembly of manganese oxide nanosheets/polyethylenimine multilayer films as electrodes for supercapacitors

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• 作者：Xiong Zhang ; Wensheng Yang ; David G. Evans
• 关键词：Manganese oxide nanosheets ; Polyethylenimine polyelectrolyte ; Layer-by-layer self-assembly ; Supercapacitor
• 刊名：Journal of Power Sources
• 出版年：2008
• 出版时间：1 October 2008
• 年：2008
• 卷：184
• 期：2
• 页码：695-700
• 全文大小：894 K

文摘

Multilayer thin films of manganese oxide nanosheets (MNSs) and polyethylenimine (PEI) polyelectrolyte have been fabricated onto various substrates via layer-by-layer self-assembly technique. UV–vis absorption spectra showed that the absorbance values at the characteristic wavelength of the multilayer films increased almost linearly with the number of PEI/MNS bilayers. Field emission scanning electron microscope (FESEM) images indicated that the surface of the multilayer film was rather smooth and dense. The electrochemical performances of (PEI/MNS)_n films on indium–tin oxide (ITO)-coated glass substrates were investigated by cyclic voltammetry and constant current charge–discharge test from 0 to 0.9 V in a 2 M KCl aqueous solution. The multilayer films showed excellent electrochemical activity, high reversibility and high power density. A specific capacitance value of 288 F g⁻¹ was obtained at a current density of 1.25 A g⁻¹ for (PEI/MNS)₁₀ film in 2 M KCl aqueous solution. The specific capacitance decreased 9.5 % of initial capacity over 1000 cycles at a high current density of 2.5 A g⁻¹. These good electrochemical properties could be attributed to the special microstructure of the electrode.