| Summary: | 碩士 === 國立臺灣大學 === 材料科學與工程學研究所 === 106 === Flexible electronic devices have great potential as a new generation, light weight, flexible wearable applications for healthcare, communication and sportswear. The flexible supercapacitors are one of the most promising candidates due to their long cycle stability, high power density and safety.
In this thesis a binary composites of oxidized carbon nanotube or graphene/PANI, ternary composites of oxidized carbon nanotube/graphene/PANI and quaternary composites of metal oxides/oxidized carbon nanotube/graphene/PANI were prepared by electro-polymerization deposition on carbon fiber and carbon cloth respectively. Their surface morphology and compositions were investigated by scanning electron microscopy (SEM), energy dispersive X-ray microanalysis (EDX) and Fourier transform infrared spectroscopy (FTIR). The results conform the formation of composite material. The particle size and size distribution of the metal oxides were measured by transmission electron microscopy (TEM), X-ray diffraction (XRD) and dynamic light scattering (DLS). Electrochemical measurements including galvanostatic charge discharge, cyclic voltammetry and electrochemical impedance were employed to evaluate their specific capacitance. The highest specific capacitances reach to 1084F/g, 888F/g, and 804F/g at 1A/g and 803F/g, 563F/g, and 371F/g at 20A/g for oxidized carbon nanotube/graphene/PANI composites incorporating with 1wt%RuO2, 2wt%MnO2 and 1wt%NiO respectively.
Flexible Symmetrical Supercapacitor (FSSC) were also fabricated by using GO/EMITFSI ionic liquid composite as gel type electrolyte. The FSSC shows a remarkable performance including good capacitance (513 F/g, 478 F/g, 441 F/g, 431 F/g, 394 F/g at 1A/g for 1wt%RuO2/oxidized carbon nanotube/graphene/PANI, 2wt% MnO2 oxidized carbon nanotube/graphene/PANI, 1wt%NiO/ oxidized carbon nanotube/graphene/PANI respectively), great capability retention at 20A/g and excellent cycle life. 1wt%RuO2/oxidized carbon nanotube/graphene/PANI shows the maximum energy density of 37Wh/kg and the highest power density of 13kW/kg. We also demonstrate actual performance of FSSC by lighting up a red LED. Therefore, our study for flexible supercapacitor holds great potential for next generation lightweight and flexible electronics.
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