工學院: 材料科學與工程學研究所指導教授: 林金福蘇柏翰Su, Pai-HanPai-HanSu2017-03-032018-06-282017-03-032018-06-282015http://ntur.lib.ntu.edu.tw//handle/246246/273131本論文主要著重以簡易的方法製備可饒式電極並與膠態電解質一併應用於超級電容上。我們應用原位化學聚合法在可撓石墨箔上長出高比表面積之聚苯胺奈米柱陣列。我們以SEM、TGA以及各式電化學量測，包括恆電流充放電、循環伏安法和交流阻抗分析來鑑定以不同濃度之苯胺製備的聚苯胺電極。根據結果，我們發現聚苯胺之比電容與其表面結構有直接關聯，當以0.01M之苯胺生成聚苯胺時，其結構為整齊排列的奈米柱陣列，並擁有最好的比電容值。在1 A/g 時，其值為737.29 F/g，且在11 A/g 時仍能保有474.60 F/g 。 為了進一步提升比電容值，我們將石墨烯量子點物理吸附於聚苯胺電極表面。石墨烯量子點在其邊界擁有許多帶負電的氧化基團，故能與帶有正電之聚苯胺緊密吸附，從反射式FTIR的結果便能證明。除此之外，因為石墨烯量子點的粒徑極小且分散性極佳，我們可以從TEM發現PANI/GQDs複合電極的比表面積並未因石墨烯量子點的吸附而減少。同時，我們以電化學量測來證實，藉由吸附石墨烯量子點，我們可以增進其電容表現。從1.5 mg/ml 石墨烯量子點的懸浮液製備而得的PANI/GQDs複合電極擁有最佳之比電容，在1 A/g時其值為965.38 F/g，相較於未經石墨烯量子點處理的電極，其比電容值約提升30%。在交流阻抗分析中，我們發現介面氧化還原反應的電荷轉移電阻皆有明顯下降，推論其原因為吸附在聚苯胺表面的石墨烯量子點可以如漏斗般地集束電子，使其更容易穿越界面並促進介面氧化還原反應。 最後，我們製備PANI/GQDs 之複合電極並搭配以氧化石墨烯膠化之EMITFSI離子液體來組裝成膠態超級電容以解決一般液態超級電容漏夜之問題。在參雜氧化石墨烯後之EMITFSI，因為庫倫作用力使氧化石墨烯與離子液體緊密吸引，使其因分子運動受阻而膠化。此外，離子吸附在氧化石墨烯上形成的3D立體結構可如高速公路般讓離子快速通過，故離子導電度會大幅增加。此外EMITFSI較其他離子液體疏水，然而聚苯胺為親水，氧化石墨烯的參雜可以可改善其離子導電度。當加入4 wt%之氧化石墨烯時系統達到膠化點，成為不可流動態，此時比電容值也達到最佳化，其值在1 A/g時為151.06 F/g。長效循環測試的結果也顯示膠化後的電解質相較於一般液態電解質能有更好的穩定度。The main idea of this thesis was to fabricate a flexible electrode with facile process for gel type supercapacitor. In-situ chemical polymerization of aniline was employed for the growth of PANI nanowire array on graphite foil with high surface area. We used SEM, TGA and electrochemical measurement including Galvanostatic charge discharge, cyclic voltammetry and EIS to characterize the PANI electrode that synthesized in different concentrations of aniline. The correlation between the capacitance and surface morphology of PANI polymerized in different aniline concentrations were investigated. When the concentration of aniline for reaction was 0.01 M, nanowire array was fabricated with the optimized specific capacitance reaching 737.29 F/g at 1 A/g and still remaining 474.60 F/g at 11 A/g. To further improve the specific capacitance, PANI electrode was physisorbed with GQDs which were prominent in their oxygen-related chemical functionalities on the edge site. Accordingly, negative-charged GQDs could adsorb on positive-charged PANI easily as evidenced by FTIR-ATR. In addition, from TEM images, the surface of PANI/GQDs would not be reduced because of the small particle size and great dispersity of GQDs. Electrochemical measurements were also conducted to support the observed enhancement of capacitive performance. For PANI/GQD nanocomposites prepared by immersing PANI in 1.5 mg/ml GQDs suspension, the best specific capacitance obtained was 965.38 F/g at 1 A/g, ~30% higher than that without GQDs. EIS measurements also confirmed that both interface and electron charge transfer resistances were decreased significantly. It is believed that the GQDs on the PANI surface could serve as an electron funnel facilitating the charge transfer between the interfaces and enhancing faradaic redox reaction. To overcome the leakage problem of liquid type electrolyte, we fabricated the gel type supercapapcitor with PANI/GQDs composite electrode and GO-doped EMITFSI ionic liquid. Doping with GO, the ion conductivity of EMITFSI would increase significantly because strong Coulombic force between GO and EMITFSI hindered the motion of molecule and GO as a 3D network acted like an ion “highway” throughout the gel electrolyte. When 4 wt% of GO was added to the EMITFSI, the gel point was reached. The best specific capacitance of 151.06 F/g at 1 A/g was also obtained. Cycle number test of charge-discharge indicated that the supercapacitor with Go-doped gel electrolyte had better durability than that with aqueous electrolyte.23569521 bytesapplication/pdf論文公開時間: 2015/9/17論文使用權限: 同意有償授權(權利金給回饋學校)超級電容聚苯胺可撓石墨箔石墨烯量子點氧化石墨烯離子液體化學沉積SupercapacitorPolyanilineFlexible Graphite FoilGraphene Quantum DotsGraphene OxideIonic LiquidChemical Depositionthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/273131/1/ntu-104-R02527028-1.pdf