氮氣大氣噴射電漿製程於石墨烯-聚苯胺及石墨烯-碳黑超級電容之應用

Application of nitrogen atmospheric-pressure plasma jet processes to graphene-polyaniline and graphene-carbon black supercapacitors

錢虹樺(Hung-Hua Chien)

指導教授 ： 陳建彰

國立臺灣大學/工學院/應用力學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201801873

摘要

本研究主要分為兩大部分，第一部分為利用直流脈衝常壓噴射電漿改質碳纖維布作為基材，並以還原氧化石墨烯-聚苯胺奈米複合材料作為電極應用於軟性超級電容，從此研究可發現改質後的碳纖維布具有親水性，使電解液能完全滲入多孔電極，進而改善電容特性。以掃描速率為2 mV/s之循環伏安法量測，比克電容值為1160.4 F/g ，面積比電容值為213.78 mF/cm2。相較於未改質碳纖維布，電容值約提升84 %。以電化學阻抗頻譜分析(EIS)結果可得知改質後的碳纖維布，具有較小的電荷轉移電阻及較高的電雙層電容及法拉第電容。從此研究證實常壓噴射電漿處理碳纖維布可快速提升軟性超級電容之電容特性。
第二部分主要研究碳黑及還原氧化石墨烯-碳黑之電容特性比較，先以網印法網印電極於碳布上，再以常壓噴射電漿燒結電極材料。X射線光電子能譜分析(XPS)及掃描式電子顯微鏡(SEM)發現經常壓噴射電漿處理後，可快速移除有機物並形成奈米多孔結構，其最佳燒結時間皆為20秒。以循環伏安法之掃描速率為2 mV/s量測，還原氧化石墨烯-碳黑及碳黑之軟性超級電容比電容值分別為162.68 F/g及91.84 F/g。由於還原氧化石墨烯-碳黑具有較高的表面積及較小的電荷轉移電阻，可改善電解液及電極介面並提高超級電容之電容值。經1000次循環伏安法穩定性量測，電容維持率分別約為98和95%，表示此電容具有優越的穩定性。

關鍵字

常壓噴射電漿 ； 還原氧化石墨烯 ； 聚苯胺 ； 碳黑 ； 軟性超級電容 ； 表面改質 ； 奈米複合材料

並列摘要

In the first part, we use dc-pulse atmospheric pressure plasma jet (APPJ) to process the carbon cloth for polyaniline (PANI)-reduced graphene oxide (rGO) nanocomposite electrodes of flexible supercapcitors. Nitrogen APPJ treatment improves hydrophilicity of the carbon cloth and facilitates the penetration of the electrolyte into the porous electrodes, thereby enhancing the capacitive performance. With APPJ surface treatment of carbon cloth before screen-printing the PANI-rGO nanocomposite, the supercapacitor displays an excellent specific and areal capacitance of 1160.4 F/g and 213.78 mF/cm2 (evaluated by cyclic voltammetry under a potential scan rate of 2 mV/s), respectively. In comparison to that without APPJ treatment, the capacitance improves by ~84% with APPJ treatment of carbon cloth. Electrochemical impedance spectroscopy (EIS) measurements shows lower charge transfer resistance and higher electrical double-layer capacitance and faradaic capacitance for supercapacitor with APPJ-treated carbon cloth. This study indicates that APPJ treatment on carbon cloth is an ultrafast approach to enhance the supercapacitance performance of a flexible supercapacitor.
In the second part, we compare the supercapacitance performance with APPJ processed carbon black (CB) and rGO-CB nanocomposite supercapacitors. X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) show that APPJ can rapidly remove the organic binders to form nanoporous structures. The optimal APPJ processing time is 20 s. The 20-s APPJ-processed rGO-CB and CB supercapacitors can achieve the specific capacitance of 162.68 and 91.84 F/g, as evaluated by cyclic voltammetry under a potential scan rate of 2 mV/s. Higher surface area and lower charge transfer rate indicate improved interface between electrode and electrolyte, thereby increasing the capacitive value. The capacitance retention rates of rGO-CB and CB supercapacitors are ~98% and ~95% after 1000 cycles CV cycling stability test, representing promising electrochemical stability.

並列關鍵字

atmospheric pressure plasma jets ； reduced graphene oxide ； polyaniline ； carbon black ； flexible supercapacitor ； surface treatment ； nanocomposites

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