受到能源枯竭與環境變遷的影響，新能源的開發及既有能源的有效利用成為 眾所矚目的研究課題。不論是超電容器或者燃料電池的材料開發都在此領域佔有 重要的一席之地，在本文中從基礎碳材的合成、表面改質、觸媒材料佈植到電極 製程的探討做了一系列的研究，也發展出迅速便捷的 TCE 量測方法。雖然，最 終的成品與達到具有商品化價值的目標尚有一段不小的差距，不過在研究過程中 卻獲致許多珍貴的數據，也累積了許寶貴的實務經驗。重要的結論包括〆 1. 以將粉體材料製成 TCE，對其電化學性質量測具有極大的便利性，不僅製作
方法簡單，只需少許的材料，更重要的是其再現性高，無論是 CV， CRC， 或 交流阻抗法所得的數據都有具有良好的一致性，與文獻資料對照也驗證了 TCE 的正確性，是本研究所新發展出獨特的粉體材料電化學量測方法。
2. CNCs 是在缺氧的氣氛之下，使用乙炔做為碳源以火焰燃燒法所製備具中空結 構與石墨烯層的奈米碳材，從孔徑分布得知所製備的奈米碳膠囊是以中孔結 構(孔徑介於 20 Å <Dp < 500 Å )為主的多孔性材料。以乙炔流量 2.0 SLM 的氣 源而言，氧氣流量控制於 0.7 SLM 可以得到產率約 26 %的碳材，其 BET 比表 面積約 300 m2/g 是能兼顧產率的最佳製備條件。碳顆粒的奈米碳膠囊直徑約 為 10~25 nm，碳球彼此間的石墨烯層糾結相通。由於具備石墨烯片的結構因 此預期導電性佳，又由於中空結構所以質輕密度低，做為電極材料時具有提 高單位質量能量密度的優點。
3. 初合成之 CNCs 採用物理法的高溫氣體氧化法及化學的酸蝕法進行表面改質，
以 950 ℃CO2氣體經過 8 小時的改質處理之後，表面積可高達 2019 m2/g，且 中巨孔比表面積佔 92.6 %。在 1N H2SO4比電容值可由原來的 60 F/g 提高到 200 F/g 以上。以空氣做為 CNCs 的改質劑時，孔隙的發展模式應與 CO2相 近，亦可依處理時間來調控表面積的大小。以空氣為改質劑較之於 CO2有溫 度較低及時間較短的優點，經過 air 處理 15 分鐘時達到最高值 852.93 m2/g，
比電容值達到 110 F/g 左右。以濃硝酸溶液為改質劑的化學改質法，對於 CNCs 的孔隙調整並不容易，也難以有效提昇其比表面積，水相的反應造成表面的 官能基團組成發生較大的變化，改質後的 CNCs 比電容值達到 100 F/g 左右。
但因造成比電容值提高的主要原因是偽電容效應的提高之故，不利於高功率 放電的性能。
4. 以共沈澱法所製備之 RuO2〃xH2O/CNCs 複合材料於硫酸溶液中的 CV 圖顯示 在 0.4~0.7 V 的電壓範圍有較為明顯的氧化電流波峰出現，由此可見此複合材 料具有更為顯著的贗電容特性。RuO2〃xH2O/CNCs 複合材料比電容值可達到 490 F/g，雖然如此，但在高功率時比電容衰減較為嚴重的現象。共沈澱法製 備的詴樣經後續不同的熱處理程序發現，不管是在大氣或者是在水熱環境中 進行熱處理，均同樣的造成比電容值有明顯下降的情形，尤其是在大氣環境
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中更為明顯，但可提高功率密度以及循環壽命。
5. RuTa 二元複合氧化物材料在比電容性能的表現象優於純 Ru 氧化物。其中 Ru〆 Ta 金屬元素莫耳比為 8:2 時所製備之氧化物塗層具有最高的比電容值，依 CRC 法所得，其比電容值約為 350 F/g，若單獨計算 Ru 氧化物部份其比電容值約 為 430 F/g。RuTa 二元複合氧化物電容材料與碳基電容材料最大的差異在於其 更為優異的導電度以及高功率充放電性質，比電容值在 100 mV/s 掃描速率時 仍能保持在 5 mV/s 掃描速率時 80%以上的比率，CRC 法量測出之 iR drop 在 2 mV 左右遠低於碳基材料。隨著塗層厚度的提高，RuTa 二元複合氧化物材料 的比電容值有顯著下降的趨勢。雖然如此，商業化的超電容器電極製備仍以 追求高單位面積的電容量為重要參數。因此，藉著塗層加厚以提昇高同樣尺 寸電極的電容量是必要的手段，經 8 回塗佈所製得的電極以單位面積計算的 比電容質達到 0.82 F/cm2已然接近實用化的階段。
6. 以 CV 法所製備之 PANI 詴樣具有很高的比電容值，在低掃描速率時甚至可達 到 600 F/g 以上，但卻受到掃描速率的影響非常顯著，意味著 PANI 電容材料 雖然具有高比電容值，但在仍侷限於法拉第反應的限制，並不適合在高功率 的應用。此外，循環壽命低也是較為致命性的缺點。
7. 以 BP2000 商品、經表面改質處理之後的自製 CNCs 材料、RuO2.xH2O/CNCs 複合材料等電容材料，添加 2.5 %石墨為導電材料、10%PTFE 及 2.5 % PVA 為粘結劑，為能夠兼顧電極結構強度、電解液親和性以及導電性能的配方組 合。所製備 4×5 cm2尺寸的二極式超電容器，其性質相較於可取得市售超電容 性商品如 Nesscap-2.7 V 100 F、 Cooper-2.5 V 100 F，其 ESR 及自放電率兩個 參數遠優於自製的電容器，不過在單位面積比電容及洩漏電流性能上自製的 電容器則有較佳的表現。
除了對新型碳氣凝膠、活性碳材等材料進行製備技術開發之外，為達實用化 的價值，製程條件的改良、自動化製程開發以及成本的降低將是下一階段的重要 工作之一。我們的研究已建立相當完整的材料製備、篩選、改質以及製程優化的 研究雛型，對於相關領域的研究都具有參考的價值，期望在最近幾年之內，台灣 能有更多超級電容器的產業興起。另外，碳基材料在能源產業應用性的拓展也相 當值得投入，例如以碳基材料做為貯氫媒介、CO2吸附劑、抗氧化型的貴金屬觸 媒載體製備以及引入 N, Si 元素以提昇 PANI 壽命等，都是我們在研究過程中曾 渉及但受限於時間而無法深入探討的課題，希望在未來的幾年可以有更為充裕的 時間與人力投入，在現今的研究基礎上有更進一歩的成果展現。
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參考資料
[1] Conway BE. Electrochemical Supercapacitors: Scientific, Fundamentals andTechnological Applications. 1999.
[2] Ashtiani C, Wright R, Hunt G. Ultracapacitors for automotive applications.
Journal of Power Sources. 2006;154(2):561-6.
[3] Huang J, Sumpter BG, Meunier V. A universal model for nanoporous carbon supercapacitors applicable to diverse pore regimes, carbons, and electrolytes.
Chem Eur J. 2008;14:6614-26.
[4] Zheng JP, Huang J, Jow TR. The Limitations of Energy Density for Electrochemical Capacitors. Journal of The Electrochemical Society.
1997;144(6):2026-31.
[5] Conway BE, Birss V, Wojtowicz J. The role and utilization of pseudocapacitance for energy storage by supercapacitors. Journal of Power Sources. 1997;66(1-2):1-14.
[6] Burke A. Ultracapacitors: why, how, and where is the technology. Journal of Power Sources. 2000;91(1):37-50.
[7] Ruiz V, Blanco C, Santamaria R, Ramos-Fernandez JM, Martinez-Escandell M, -Escribano A, et al. An activated carbon monolith as an electrode material for supercapacitors. Carbon. 2009;47(1):195-200.
[8] Pandolfo AG, Hollenkamp AF. Carbon properties and their role in supercapacitors. Journal of Power Sources. 2006;157(1):11-27.
[9] Shi H. Activated carbons and double layer capacitance. Electrochimica Acta.
1996;41(10):1633-9.
[10] Gamby J, Taberna PL, Simon P, Fauvarque JF, Chesneau M. Studies and characterisations of various activated carbons used for carbon/carbon supercapacitors. Journal of Power Sources. 2001;101(1):109-16.
[11] Qu D, Shi H. Studies of activated carbons used in double-layer capacitors. J Power Sources. 1998;74:99-107.
[12] SING KSW. Reporting Physisorption Data for Gas/solid Systems with Special Reference to the Determination of Surface Area and Porosity. Pure & App!
Chem 1985;57(4):603-19.
[13] Ahmadpour A, Do DD. The preparation of active carbons from coal by chemical and physical activation. Carbon. 1996;34(4):471-9.
[14] Teng H, Wang S-C. Preparation of porous carbons from phenol-formaldehyde resins with chemical and physical activation. Carbon. 2000;38(6):817-24.
[15] Adachi K, Kurosaki, Takeo, Iwashima, Yoshinori Double layer capacitor
175
with high capacitance carbonaceous material electrodes US Patent.
1995;5,430,606.
[16] Weng T-C, Teng H. Characterization of High Porosity Carbon Electrodes Derived from Mesophase Pitch for Electric Double-Layer Capacitors. Journal of The Electrochemical Society. 2001;148(4):A368-A73.
[17] Endo M, Kim YJ, Ohta H, Ishii K, Inoue T, Hayashi T, et al. Morphology and organic EDLC applications of chemically activated AR-resin-based carbons.
Carbon. 2002;40(14):2613-26.
[18] Wu F-C, Tseng R-L, Hu C-C, Wang C-C. Physical and electrochemical characterization of activated carbons prepared from firwoods for supercapacitors. Journal of Power Sources. 2004;138(1-2):351-9.
[19] Rufford TE, Hulicova-Jurcakova D, Khosla K, Zhu Z, Lu GQ. Microstructure and electrochemical double-layer capacitance of carbon electrodes prepared by zinc chloride activation of sugar cane bagasse. Journal of Power Sources.
2010;195(3):912-8.
[20] Rufford TE, Hulicova-Jurcakova D, Zhu Z, Lu GQ. Nanoporous carbon electrode from waste coffee beans for high performance supercapacitors.
Electrochemistry Communications. 2008;10(10):1594-7.
[21] Simon P, Gogotsi Y. Materials for electrochemical capacitors. Nat Mater.
2008;7(11):845-54.
[22] Obreja VVN. On the performance of supercapacitors with electrodes based on carbon nanotubes and carbon activated material--A review. Physica E:
Low-dimensional Systems and Nanostructures. 2008;40(7):2596-605.
[23] Teng H, Chang Y-J, Hsieh C-T. Performance of electric double-layer capacitors using carbons prepared from phenol-formaldehyde resins by KOH etching.
Carbon. 2001;39(13):1981-7.
[24] Zhang L, Liu H, Wang M, Chen L. Structure and electrochemical properties of resorcinol-formaldehyde polymer-based carbon for electric double-layer capacitors. Carbon. 2007;45(7):1439-45.
[25] Pekala RW. Low density, resorcinol-formaldehyde aerogels US Patent 4,873,218. 1989.
[26] Pekala RW, Farmer JC, Alviso CT, Tran TD, Mayer ST, Miller JM, et al. Carbon aerogels for electrochemical applications. Journal of Non-Crystalline Solids.
1998;225(1):74-80.
[27] Scherdel C, Scherb T, Reichenauer G. Spherical porous carbon particles derived from suspensions and sediments of resorcinol-formaldehyde particles. Carbon.
2009;47(9):2244-52.
[28] Zhu Y, Hu H, Li W, Zhang X. Resorcinol-formaldehyde based porous carbon as
176
an electrode material for supercapacitors. Carbon. 2007;45(1):160-5.
[29] Zhu Y, Hu H, Li W-C, Zhang X. Cresol-formaldehyde based carbon aerogel as electrode material for electrochemical capacitor. Journal of Power Sources.
2006;162(1):738-42.
[30] Petricevic R, Glora M, Fricke J. Planar fibre reinforced carbon aerogels for application in PEM fuel cells. Carbon. 2001;39(6):857-67.
[31] Li J, Wang X, Wang Y, Huang Q, Dai C, Gamboa S, et al. Structure and electrochemical properties of carbon aerogels synthesized at ambient temperatures as supercapacitors. Journal of Non-Crystalline Solids.
2008;354(1):19-24.
[32] Dicks AL. The role of carbon in fuel cells. Journal of Power Sources.
2006;156(2):128-41.
[33] Wu C-Y, Wu P-W, Lin P, Li Y-Y, Lin Y-M. Silver-Carbon Nanocapsule Electrocatalyst for Oxygen Reduction Reaction. Journal of The Electrochemical Society. 2007;154(10):B1059-B62.
[34] Neburchilov V, Wang H, Martin JJ, Qu W. A review on air cathodes for zinc-air fuel cells. Journal of Power Sources.In Press, Corrected Proof.
[35] Shin HC, Cho WI, Jang H. Electrochemical properties of carbon-coated LiFePO4 cathode using graphite, carbon black, and acetylene black.
Electrochimica Acta. 2006;52(4):1472-6.
[36] Richner R, Müller S, Wokaun A. Grafted and crosslinked carbon black as an electrode material for double layer capacitors. Carbon. 2002;40(3):307-14.
[37] Beck F, Dolata M, Grivei E, Probst N. Electrochemical supercapacitors based on industrial carbon blacks in aqueous H2SO4. Journal of Applied Electrochemistry. 2001;31(8):845-53.
[38] Frackowiak E, Jurewicz K, Delpeux S, Béguin F. Nanotubular materials for supercapacitors. Journal of Power Sources. 2001;97-98:822-5.
[39] Barisci* JN, Wallace* GG, Baughman RH. Electrochemical studies of single-wall carbon nanotubes in aqueous solutions. Journal of Electroanalytical Chemistry. 2000;488(2):92-8.
[40] Frackowiak E, Beguin F. Carbon materials for the electrochemical storage of energy in capacitors. Carbon. 2001;39(6):937-50.
[41] Frackowiak E, Khomenko V, Jurewicz K, Lota K, Beguin F. Supercapacitors based on conducting polymers/nanotubes composites. Journal of Power Sources.
2006;153(2):413-8.
[42] Niu C, Sichel EK, Hoch R, Moy D, Tennent H. High power electrochemical capacitors based on carbon nanotube electrodes. Applied Physics Letters.
1997;70(11):1480-2.
177
[43] Liu CG, Fang HT, Li F, Liu M, Cheng HM. Single-walled carbon nanotubes modified by electrochemical treatment for application in electrochemical capacitors. Journal of Power Sources. 2006;160(1):758-61.
[44] Ye J-S, Liu X, Cui HF, Zhang W-D, Sheu F-S, Lim TM. Electrochemical oxidation of multi-walled carbon nanotubes and its application to electrochemical double layer capacitors. Electrochemistry Communications.
2005;7(3):249-55.
[45] Rodriguez-Reinoso F, Molina-Sabio M, Gonzalez MT. The use of steam and CO2 as activating agents in the preparation of activated carbons. Carbon.
1995;33(1):15-23.
[46] Hu C-C, Chen W-C. Effects of substrates on the capacitive performance of RuOx.H2O and activated carbon-RuOx electrodes for supercapacitors.
Electrochimica Acta. 2004;49(21):3469-77.
[47] Hu C-C, Huang Y-H. Cyclic Voltammetric Deposition of Hydrous Ruthenium Oxide for Electrochemical Capacitors. Journal of The Electrochemical Society.
1999;146(7):2465-71.
[48] Hu C-C, Liu M-J, Chang K-H. Anodic deposition of hydrous ruthenium oxide for supercapaciors: Effects of the AcO- concentration, plating temperature, and oxide loading. Electrochimica Acta. 2008;53(6):2679-87.
[49] Hu C-C, Chang K-H, Lin M-C, Wu Y-T. Design and Tailoring of the Nanotubular Arrayed Architecture of Hydrous RuO2 for Next Generation Supercapacitors. Nano Letters. 2006;6(12):2690-5.
[50] Zheng JP, Cygan PJ, Jow TR. Hydrous Ruthenium Oxide as an Electrode Material for Electrochemical Capacitors. Journal of The Electrochemical Society. 1995;142(8):2699-703.
[51] Chou S, Cheng F, Chen J. Electrodeposition synthesis and electrochemical properties of nanostructured [gamma]-MnO2 films. Journal of Power Sources.
2006;162(1):727-34.
[52] Li J, Wang X, Huang Q, Gamboa S, Sebastian PJ. A new type of MnO2·xH2O/CRF composite electrode for supercapacitors. Journal of Power Sources. 2006;160(2):1501-5.
[53] Subramanian V, Zhu H, Wei B. Nanostructured MnO2: Hydrothermal synthesis and electrochemical properties as a supercapacitor electrode material. Journal of Power Sources. 2006;159(1):361-4.
[54] Patil UM, Salunkhe RR, Gurav KV, Lokhande CD. Chemically deposited nanocrystalline NiO thin films for supercapacitor application. Applied Surface Science. 2008;255(5, Part 2):2603-7.
[55] Wu NL. Nanocrystalline oxide supercapacitors. Mater Chem Phys.
178 2002;75:6-11.
[56] Jamadade VS, Dhawale DS, Lokhande CD. Studies on electrosynthesized leucoemeraldine, emeraldine and pernigraniline forms of polyaniline films and their supercapacitive behavior. Synthetic Metals. 2010;160(9-10):955-60.
[57] Hu C-C, Chen E, Lin J-Y. Capacitive and textural characteristics of polyaniline-platinum composite films. Electrochimica Acta.
2002;47(17):2741-9.
[58] Fusalba F, Gouerec P, Villers D, Belanger D. Electrochemical Characterization of Polyaniline in Nonaqueous Electrolyte and Its Evaluation as Electrode Material for Electrochemical Supercapacitors. Journal of The Electrochemical Society. 2001;148(1):A1-A6.
[59] Rudge A, Davey J, Raistrick I, Gottesfeld S, Ferraris JP. Conducting polymers as active materials in electrochemical capacitors. Journal of Power Sources.
1994;47(1-2):89-107.
[60] Chen W-C, Wen T-C, Teng H. Polyaniline-deposited porous carbon electrode for supercapacitor. Electrochimica Acta. 2003;48(6):641-9.
[61] Mi H, Zhang X, Ye X, Yang S. Preparation and enhanced capacitance of core-shell polypyrrole/polyaniline composite electrode for supercapacitors.
Journal of Power Sources. 2008;176(1):403-9.
[62] SIEMIENIEWSKA KSWSDHERAWHLMRAPJRT. Reporting Physisorption Data for Gas/solid Systems with Special Reference to the Determination of Surface Area and Porosity. Pure & App! Chem 1985;57(4).
[63] Lippens BC, de Boer JH. Studies on pore systems in catalysts : V. The t method.
Journal of Catalysis. 1965;4(3):319-23.
[64] Tuinstra F, Koenig JL. Raman Spectrum of Graphite. The Journal of Chemical Physics. 1970;53(3):1126-30.
[65] Lahaye J. The chemistry of carbon surfaces. Fuel. 1998;77(6):543-7.
[66] Fanning PE, Vannice MA. A DRIFTS study of the formation of surface groups
[66] Fanning PE, Vannice MA. A DRIFTS study of the formation of surface groups