本論文探討奈米碳管的密度調變與電極反應物氧化釕的沉積法等效應對提升電化學超高電容器之性能的影響。此研究提供有效利用奈米碳管的高表面積特性，並配合多種奈米電極反應物在碳管上的附著機制以獲得較大反應面積近而提高電化學反應效率的研發結果。
有關奈米碳管的密度控制，是利用不同面積比之鐵-矽雙金屬，及不同含鐵成分的合金靶材，將催化劑鐵濺鍍於基板以做為成長奈米碳管之疏密性與準直性的調變。結果發現鐵-矽雙金屬面積比為3:1時，在濺鍍氧化釕後電容值可達42.3mF/cm2。奈米碳管的密度與準直性對提升電極材料之有效披覆表面積的影響，亦在本文中討論。
在電化學法沉積氧化釕電極材料的研究中，我們發現將沉積後的電極材料回火，有助於提升電子/離子傳輸。實驗得到回火溫度在200℃時，電容值與電流密度都有明顯的增加。以循環伏安法沉積反應物時亦觀察到氧化釕有效成膜披覆在奈米碳管管壁上，較直流電鍍法為佳。而脈衝電鍍能使氧化釕均勻的以顆粒狀成核於奈米碳管上。在偏壓濺鍍部份，我們觀察到加大偏壓，能使氧化釕之晶粒細化。奈米碳管生長時的氮氣調變，對氧化釕的沈積效果有相當顯著的影響，在氮氣流量約20 sccm以下時可得到最佳之電容效應。
最後，我們以簡單的電容封裝做電路測試，電容器在未完全封裝的情況，其全電極可在24小時的測試時間下，以600-2000 mV/sec的掃描速率可維持約略相等之電容值。
This thesis investigated the effect of the density control of carbon nanotubes (CNTS) and the deposition methods of ruthenium oxide on the capacitive performance of electrochemical super-capacitor. The research provides the experimental results of the high surface area utilization of CNTS and the influence of electrode nano-particle deposition methods on the efficiency of electrolytic reaction
The density of CNTS was altered by varying the catalysis concentration of alloy and the ratio of covered area on catalysis-metal surface. The value of capacitance changed with the ratio of iron-silicon bimetal area, and a value of 42.3mF/cm2 can be achieved at the ratio of 3:1. The influence of the density and the alignments of CNTS on the effective surface area for the electrode particle plating were discussed as well as the capacitive performance.
The deposition of electrode particles by the method of electrochemical plating was also studied. It was found that suitable annealing temperature enhanced the crystallization of the electrode material, which provides a better condition for ion-electron transport. Both capacitance and current density were found increased by the effect of annealing at temperature of 200℃. Besides, on the wall of CNTS was observed fully covered with the RuO2 membrane by the method of cyclic voltammetry deposition, and the surface area can be great promoted at the electrochemical reactant. In the pulse electro-deposition, ruthenium oxide particle was found nucleated in uniform grain on the surface of CNTS.
The effect of nitrogen doping during CNTS growth followed by ruthenium oxide deposition was also discussed in this thesis. An amount of defects was generated by nitrogen atom occupied on the substitutional site of carbon, and porous CNTS were created. Ruthenium nano-particle can be trapped in the holes with suitable size. A nitrogen flow rate at 20 sccm was observed to achieve the best capacitive performance of 28mF/cm2, comparing to three other flow rates which have been chosen.
Finally, a simple package was made for the capacitor to test the device performance. It was found that the full electrode can keep almost the same value of capacitance during the 24 hours test time at scanning rate of 600-2000 mV/sec.
