近幾十年來，全球經濟大幅發展，世界對於石化能源(石油、天然氣、煤炭等)需求量大增，大量使用石化能源導致該資源枯竭，甚至造成全球氣候變遷，可再生能源做為替代能源逐漸被大眾使用，而可再生能源的儲能問題為重要的研究方向之一，常見的儲能裝置有能量密度大，但功率密度小且充放電時間長的燃料電池與鋰電池，抑或是功率密度大且充放電快速，但能量密度小的傳統電容器，而超級電容器作為具備一定的能量密度與功率密度，且有比電池更快的充放電速率作為本次的研究目標。在本實驗中，首先預處理集流體基材，提升其反應活性點位，並以循環伏安電鍍法沉積高電化學性能之活性物質於改質後之基材，接著利用SEM、XRD、Raman、XPS與TEM進行物性分析，再利用CV、GCD、EIS、Cycle testing與GCPL測試材料之電化學性質。
第一部分，使用不同金屬前驅物(Mn(NO3)2、Fe(NO3)3、Co(NO3)2、Ni(NO3)2)與硫脲配製電鍍液，使用泡沫鎳作為集流體基材，利用循環伏安電鍍法沉積硫摻雜之二元金屬氫氧化物薄膜於泡沫鎳上，經電化學分析，可確定最合適的二元金屬電鍍液。
第二部分，預處理泡沫鎳基材，使用硝酸水浴法改質泡沫鎳基材平坦之表面結構，成功生長多層狀奈米結構之六方晶體氫氧化鎳結構，以增加基材的反應活性位點，並通過最適化實驗參數調整(電鍍液比例、硫脲濃度、尿素濃度、電鍍迴圈數、CTAB改善均勻度)得到最佳化樣品CoNiS-OH/Ni(OH)2。經XRD與TEM分析確定此為非晶態CoNiS-OH沉積在結晶態Ni(OH)2基材上，此外XPS分析得到鈷、鎳價態為2+、3+與大量OH-和少量硫元素，以及Raman分析出Co-OH、Ni-OH與OH特徵峰，可驗證此為硫摻雜之鈷鎳雙金屬氫氧化物。電化學性質分析，於1 A/g時，比電容值為5803 F/g，能量密度為135.5 Wh/Kg，功率密度為205 W/Kg，穩定性測試於30 A/g時循環10000次充放電後，電容保持率約70%。
第三部分以PVA+KOH膠態電解質與KOH液態電解質製備AC// CoNiS-OH/Ni(OH)2混合型超級電容器，在電流密度1 A/g時比電容值分別為135.1與119.4 F/g，能量密度分別為60.8與53.8 Wh/Kg，功率密度皆為900 W/Kg，穩定性測試於10 A/g時循環10000次充放電，電容保持率皆為約88%，3小時自放電電壓衰退率分別為68%與54%，24小時自放電電壓衰退率分別為83%與71%。

In recent decades, significant global economic development has led to a substantial increase in the demand for petrochemical energy sources such as oil, natural gas, and coal. The extensive use of these resources has resulted in resource depletion and even global climate change. As a result, renewable energy has emerged as an alternative energy source, and energy storage for renewable energy has become a crucial research direction. Available energy storage devices include fuel cells and lithium batteries, which have high energy density but low power density and extended charging and discharging times, and traditional capacitors, which have immense power density and fast charging and discharging but low energy density. This study focuses on supercapacitors, which offer specific energy and power densities while enabling faster charging and discharging rates than batteries. The current collector substrate was first pre-treated in this experiment to enhance its reactive sites. Then, using the cyclic voltammetry electroplating method, an active material with high electrochemical performance was deposited on the modified substrate. Physical property analysis used SEM, XRD, Raman, XPS, and TEM techniques. The electrochemical properties of the materials were evaluated through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), electrochemical impedance spectroscopy (EIS), cycle testing, and galvanostatic cycling with potential limitation (GCPL) measurements.
In the first part, different metal precursors (Mn(NO3)2, Fe(NO3)3, Co(NO3)2, Ni(NO3)2) and thiourea were used to prepare the electroplating solution. Nickel foam was used as the current collector substrate, and sulfur-doped binary metal hydroxide thin films were deposited on the nickel foam using cyclic voltammetry electroplating. Through electrochemical analysis, the optimal binary metal electroplating solution could be determined.
In the second part, the nickel foam substrate was pre-treated using a nitric acid water bath to modify its flat surface structure. This process successfully facilitated the growth of a multilayered nanostructured hexagonal nickel hydroxide, enhancing the reactive sites of the substrate. The experimental parameters were optimized, including the plating solution ratio, thiourea concentration, urea concentration, number of plating cycles, and CTAB for improved uniformity. This optimization formed the optimized sample CoNiS-OH/Ni(OH)2. XRD and TEM analysis confirmed that the amorphous CoNiS-OH was deposited on the crystalline Ni(OH)2 substrate. XPS analysis revealed the valence states of cobalt and nickel as 2+ and 3+, with a significant amount of OH- and a small number of sulfur elements. Raman analysis identified characteristic Co-OH, Ni-OH, and OH peaks, providing evidence for sulfur-doped cobalt-nickel bimetallic hydroxide. Electrochemical property analysis showed a specific capacitance value of 5803 F/g at 1 A/g, an energy density of 135.5 Wh/Kg, and a power density of 205 W/kg. The stability test, conducted at 30 A/g with 10,000 charge and discharge cycles, resulted in a capacitance retention rate of approximately 70%.
The third part prepared AC//CoNiS-OH/Ni(OH)2 hybrid supercapacitors using a PVA+KOH gel electrolyte and a KOH liquid electrolyte. At a current density of 1 A/g, the specific capacitance values were found to be 135.1 and 119.4 F/g, while the energy densities were 60.8 and 53.8 Wh/Kg, respectively. The power densities for both cases were 900 W/kg. The stability test involved cycling the capacitors at a current density of 10 A/g for 10,000 charge and discharge cycles, and the capacitance retention rate was approximately 88%. After 3 hours of self-discharge, the two capacitors' voltage decay rates were 68% and 54%, respectively. Similarly, after 24 hours of self-discharge, the voltage decay rates were 83% and 71%, respectively.

[1] D. Kweku, O. Bismark, A. Maxwell, “Greenhouse effect: Greenhouse gases and their impact on global warming,” Journal of Scientific Research and Reports, 17 (2018) 1-9.
[2] A. Mikhaylov, N. Moiseev, K. Aleshin, “Global climate change and greenhouse effect,” Entrepreneurship and Sustainability Issues, 7 (2020) 2897-2913.
[3] F. Meunier, “The greenhouse effect: A new source of energy,” Applied Thermal Engineering, 27 (2007) 658-664.
[4] A. González, E. Goikolea, J. A. Barrena, “Review on supercapacitors: Technologies and materials,” Renewable and Sustainable Energy Reviews, 58 (2016) 1189-1206.
[5] J. Libich, J. Máca, J. Vondrák, “Supercapacitors: Properties and applications,” Journal of Energy Storage, 17 (2018) 224-227.
[6] Poonam, K. Sharma, A. Arora, “Review of supercapacitors: Materials and devices,” Journal of Energy Storage, 21 (2019) 801-825.
[7] W. Raza, F. Ali, N. Raza, “Recent advancements in supercapacitor technology,” Nano Energy, 52 (2018) 441-473.
[8] M. Şahin, F. Blaabjerg, and A. Sangwongwanich, “A comprehensive review on supercapacitor applications and developments,” Energies, 15 (2022) 3.
[9] J. Tahalyani, M. J. Akhtar, J. Cherusseri, "Characteristics of capacitor: Fundamental aspects," Handbook of Nanocomposite Supercapacitor Materials I, Springer Series in Materials Science, (2020) 1-51.
[10] A. G. Pandolfo, and A. F. Hollenkamp, “Carbon properties and their role in supercapacitors,” Journal of Power Sources, 157 (2006) 11-27.
[11] T. Christen, and M. W. Carlen, “Theory of ragone plots,” Journal of power sources, 91 (2000) 210-216.
[12] M. S. Vidhya, G. Ravi, R. Yuvakkumar, “Nickel-cobalt hydroxide: A positive electrode for supercapacitor applications,” RSC Adv, 10 (2020) 19410-19418.
[13] M. Vangari, T. Pryor, and L. Jiang, “Supercapacitors: Review of materials and fabrication methods,” Journal of Energy Engineering, 139 (2013) 72-79.
[14] B.-O. Park, C. Lokhande, P. Hyung-Sang, “Electrodeposited ruthenium oxide (RuO 2) films for electrochemical supercapacitors,” Journal of materials science, 39 (2004) 4313-4317.
[15] V. D. Patake, S. S. Joshi, C. D. Lokhande, “Electrodeposited porous and amorphous copper oxide film for application in supercapacitor,” Materials Chemistry and Physics, 114 (2009) 6-9.
[16] B. K. Kim, S. Sy, A. Yu, "Electrochemical supercapacitors for energy storage and conversion," Handbook of Clean Energy Systems, (2015) 1-25.
[17] G. Jeanmairet, B. Rotenberg, and M. Salanne, “Microscopic simulations of electrochemical double-layer capacitors,” Chem Rev, 122 (2022) 10860-10898.
[18] S. Najib, and E. Erdem, “Current progress achieved in novel materials for supercapacitor electrodes: Mini review,” Nanoscale Adv, 1 (2019) 2817-2827.
[19] M. Yaseen, M. A. K. Khattak, M. Humayun, “A review of supercapacitors: Materials design, modification, and applications,” Energies, 14 (2021).
[20] X. Chen, R. Paul, and L. Dai, “Carbon-based supercapacitors for efficient energy storage,” National Science Review, 4 (2017) 453-489.
[21] D. P. Chatterjee, and A. K. Nandi, “A review on the recent advances in hybrid supercapacitors,” Journal of Materials Chemistry A, 9 (2021) 15880-15918.
[22] N. Choudhary, C. Li, J. Moore, “Asymmetric supercapacitor electrodes and devices,” Adv Mater, 29 (2017).
[23] N. Elgrishi, K. J. Rountree, B. D. McCarthy, “A practical beginner’s guide to cyclic voltammetry,” Journal of Chemical Education, 95 (2017) 197-206.
[24] P. Pattananuwat, and D. Aht-ong, “Controllable morphology of polypyrrole wrapped graphene hydrogel framework composites via cyclic voltammetry with aiding of poly (sodium 4-styrene sulfonate) for the flexible supercapacitor electrode,” Electrochimica Acta, 224 (2017) 149-160.
[25] H. Lv, Q. Pan, Y. Song, “A review on nano-/microstructured materials constructed by electrochemical technologies for supercapacitors,” Nanomicro Lett, 12 (2020) 118.
[26] X. Pu, D. Zhao, C. Fu, “Understanding and calibration of charge storage mechanism in cyclic voltammetry curves,” Angewandte Chemie, 133 (2021) 21480-21488.
[27] J. Liu, J. Wang, C. Xu, “Advanced energy storage devices: Basic principles, analytical methods, and rational materials design,” Adv Sci (Weinh), 5 (2018) 1700322.
[28] J. Xie, P. Yang, Y. Wang, “Puzzles and confusions in supercapacitor and battery: Theory and solutions,” Journal of Power Sources, 401 (2018) 213-223.
[29] N. R. Chodankar, H. D. Pham, A. K. Nanjundan, “True meaning of pseudocapacitors and their performance metrics: Asymmetric versus hybrid supercapacitors,” Small, 16 (2020) 2002806.
[30] F. Ciucci, “Modeling electrochemical impedance spectroscopy,” Current Opinion in Electrochemistry, 13 (2019) 132-139.
[31] P. Navalpotro, M. Anderson, R. Marcilla, “Insights into the energy storage mechanism of hybrid supercapacitors with redox electrolytes by electrochemical impedance spectroscopy,” Electrochimica Acta, 263 (2018) 110-117.
[32] H. S. Magar, R. Y. A. Hassan, and A. Mulchandani, “Electrochemical impedance spectroscopy (EIS): Principles, construction, and biosensing applications,” Sensors (Basel), 21 (2021).
[33] J. Niu, B. E. Conway, and W. G. Pell, “Comparative studies of self-discharge by potential decay and float-current measurements at C double-layer capacitor and battery electrodes,” Journal of Power Sources, 135 (2004) 332-343.
[34] H. A. Andreas, “Self-discharge in electrochemical capacitors: A perspective article,” Journal of The Electrochemical Society, 162 (2015) A5047-A5053.
[35] A. Lewandowski, P. Jakobczyk, M. Galinski, “Self-discharge of electrochemical double layer capacitors,” Phys Chem Chem Phys, 15 (2013) 8692-9.
[36] K. Liu, C. Yu, W. Guo, “Recent research advances of self-discharge in supercapacitors: Mechanisms and suppressing strategies,” Journal of Energy Chemistry, 58 (2021) 94-109.
[37] C. Yuan, L. Yang, L. Hou, “Growth of ultrathin mesoporous Co3O4 nanosheet arrays on Ni foam for high-performance electrochemical capacitors,” Energy & Environmental Science, 5 (2012).
[38] R. S. Kate, S. A. Khalate, and R. J. Deokate, “Overview of nanostructured metal oxides and pure nickel oxide (NiO) electrodes for supercapacitors: A review,” Journal of Alloys and Compounds, 734 (2018) 89-111.
[39] R. Liu, A. Zhou, X. Zhang, “Fundamentals, advances and challenges of transition metal compounds-based supercapacitors,” Chemical Engineering Journal, 412 (2021).
[40] S. Liu, Y. Yin, K. San Hui, “Nickel hydroxide/chemical vapor deposition-grown graphene/nickel hydroxide/nickel foam hybrid electrode for high performance supercapacitors,” Electrochimica Acta, 297 (2019) 479-487.
[41] J. Cao, Z. Zhang, H. Li, “Facile preparation of nickel hydroxide nanoplates on nickel foam for high performance hydrogen generation,” Sustainable Energy & Fuels, 4 (2020) 5031-5035.
[42] R. Barik, and P. P. Ingole, “Challenges and prospects of metal sulfide materials for supercapacitors,” Current Opinion in Electrochemistry, 21 (2020) 327-334.
[43] T. Wang, B. Zhao, H. Jiang, “Electro-deposition of CoNi2S4 flower-like nanosheets on 3D hierarchically porous nickel skeletons with high electrochemical capacitive performance,” Journal of Materials Chemistry A, 3 (2015) 23035-23041.
[44] D. Lincot, “Electrodeposition of semiconductors,” Thin Solid Films, 487 (2005) 40-48.
[45] A. M, and A. Paul, “Importance of electrode preparation methodologies in supercapacitor applications,” ACS Omega, 2 (2017) 8039-8050.
[46] S. Shaheen Shah, S. M. Abu Nayem, N. Sultana, “Preparation of sulfur-doped carbon for supercapacitor applications: A review,” ChemSusChem, 15 (2022) 202101282.
[47] X. Ma, X. Song, Z. Yu, “S-doping coupled with pore-structure modulation to conducting carbon black: Toward high mass loading electrical double-layer capacitor,” Carbon, 149 (2019) 646-654.
[48] N. Karthik, T. N. J. I. Edison, R. Atchudan, “Electro-synthesis of sulfur doped nickel cobalt layered double hydroxide for electrocatalytic hydrogen evolution reaction and supercapacitor applications,” Journal of Electroanalytical Chemistry, 833 (2019) 105-112.
[49] S. R. Hosseini, S. Ghasemi, and S. A. Ghasemi, “Effect of surfactants on electrocatalytic performance of copper nanoparticles for hydrogen evolution reaction,” Journal of Molecular Liquids, 222 (2016) 1068-1075.
[50] M. Shimizu, K. Hirahara, and S. Arai, “Morphology control of zinc electrodeposition by surfactant addition for alkaline-based rechargeable batteries,” Phys Chem Chem Phys, 21 (2019) 7045-7052.
[51] A. Biswal, P. K. Panda, A. N. Acharya, “Role of additives in electrochemical deposition of ternary metal oxide microspheres for supercapacitor applications,” ACS Omega, 5 (2020) 3405-3417.
[52] H. Zhang, Y. Wang, C. Liu, “Influence of surfactant CTAB on the electrochemical performance of manganese dioxide used as supercapacitor electrode material,” Journal of Alloys and Compounds, 517 (2012) 1-8.
[53] S. B. Kulkarni, A. D. Jagadale, V. S. Kumbhar, “Potentiodynamic deposition of composition influenced Co1−xNix LDHs thin film electrode for redox supercapacitors,” International Journal of Hydrogen Energy, 38 (2013) 4046-4053.
[54] P. Vinothbabu, and P. Elumalai, “Tunable supercapacitor performance of potentiodynamically deposited urea-doped cobalt hydroxide,” RSC Adv., 4 (2014) 31219-3122.
[55] H. Khan, A. S. Yerramilli, A. D'Oliveira, “Experimental methods in chemical engineering: X‐ray diffraction spectroscopy— XRD,” The Canadian Journal of Chemical Engineering, 98 (2020) 1255-1266.
[56] E. Korin, N. Froumin, and S. Cohen, “Surface analysis of nanocomplexes by X-ray photoelectron spectroscopy (XPS),” ACS Biomater Sci Eng, 3 (2017) 882-889.
[57] G. S. Bumbrah, and R. M. Sharma, “Raman spectroscopy – Basic principle, instrumentation and selected applications for the characterization of drugs of abuse,” Egyptian Journal of Forensic Sciences, 6 (2016) 209-215.
[58] J. T. van Omme, H. Wu, H. Sun, “Liquid phase transmission electron microscopy with flow and temperature control,” Journal of Materials Chemistry C, 8 (2020) 10781-10790.
[59] S. Yan, K. P. Abhilash, L. Tang, “Research advances of amorphous metal oxides in electrochemical energy storage and conversion,” Small, 15 (2019) e1804371.
[60] D. S. Hall, D. J. Lockwood, S. Poirier, “Raman and infrared spectroscopy of alpha and beta phases of thin nickel hydroxide films electrochemically formed on nickel,” J Phys Chem A, 116 (2012) 6771-84.
[61] X. Wang, H. Song, S. Ma, “Template ion-exchange synthesis of Co-Ni composite hydroxides nanosheets for supercapacitor with unprecedented rate capability,” Chemical Engineering Journal, 432 (2022) 134319.