奈米碳管與錳氧化物奈米複合物超高電容器的製作與其特性之研究

Abstract

本論文探討利用氫離子作為表面活性劑，藉由電鍍製程製備出高效能與高循環次數的超級電容。超級電容是一種具有高比電容值、高功率密度、快速充放電等特性的儲能元件，其中藉由表面氧化物的價數變化達到儲能效果的稱為法拉第電容。目前以電鍍法或溶膠凝膠法製作法拉第電容通常需要高分子的表面活性劑，由於高分子在法拉第電容屬於阻值較大的物質，使得法拉第電容在高功率操作時有著嚴重的衰減。 本實驗藉由氫離子取代有機高分子來作為氧化錳的表面活性劑，使得氧化錳與奈米碳管複合材料的表面帶有正電荷，利用電鍍的方式在陰極沉積氧化錳與奈米碳管，由於少了高分子的影響使得超級電容在高功率下的衰減有效的減少。另外，本實驗也藉由加熱製程去有效的提升超級電容的比電容值，並且有效改善了法拉第電容在高循環次數下嚴重衰減的情形。

In this thesis, a high electrochemical performance and stability supercapacitor was produced by electrophoretic deposition (EPD) method using H+ ion as surfactant to ionize the surface of manganese oxide. Supercapacitors are an energy storage device with high specific capacitance, high power density, and quickly charge/discharge time. Psuedocapacitor is one classification of supercapacitors which stores charge by changing the oxidation state of transition metal oxide. At present, polymer, a high charge transfer resistant material, is required as surfactant in EPD or sol-gel process leading to deadly recession of specific capacitance at high power density operating. We substitute H+ ion for polymer as surfactant of manganese leading MnOx/CNT coaxial composite material to be ionized with positive charge so that they can be deposited on the cathodic electrode by EPD method. The situation of capacitance degradation at high scanning rate is improved due to without polymer. Besides an annealing step is introduced to this experiment to enhance the specific capacitance and reduce the degradation of capacitance after a long cycling test.