以軟性基板製備鎳基薄膜式超級電容電極

Nickel-based thin film supercapacitior electrodes on flexible substrates

陳志宏(Zhi-Hong Chen)

指導教授 ： 林炯棟

義守大學/理工學院/材料科學與工程學系/碩士(2015年)

https://doi.org/10.6343/ISU.2015.00229

摘要

本研究將無電鍍膜鍍覆在三種軟性基板上(石墨紙、鈦箔板、碳纖維紙)，並利用酸蝕刻的方式來製備超級電容電極。利用三極式電極系統以循環伏安法與充放電曲線測量其電化學性質並計算其比電容值，並以電化學交流阻抗法(EIS)分析其電化學反應機制。探討無電鍍膜的鍍覆條件及不同基板與比電容值的關係。另外，加入鈷製備出三元的無電鍍膜(Ni-Co-P)，並以硝酸進行蝕刻，研究對膜層顯微結構與比電容值的影響。
其結果顯示，在相同的鍍覆條件下，石墨紙基板所製備之鎳磷膜，在掃描速率為10mV/s，其比電容值(71 F/g)相較其他兩種基板(鈦箔板:30 F/g；碳纖維紙:52 F/g)來的高，這與鍍覆後的電極電阻大小與電荷交換阻抗有關，且與基板鍍覆後與電解液接觸的比表面積大小有關。若進一步進行蝕刻，比電容值在掃描速率為10mV/s下從原先71 F/g增加到了335 F/g，增加了4.7倍。但隨著蝕刻時間的增加，其比電容值並沒有明顯的增加。經由顯微結構觀察，發現適當的蝕刻時間可以有效地增加比表面積，但若是蝕刻時間過長則會造成膜層破壞與脫落，並不會增加比電容值。
另外，必須將原本酸性鍍液改成鹼性才能順利沉積鈷。雖然加入鈷後，比電容值並沒有明顯的提升，但對於其膜層的抗腐蝕性卻有明顯的提升。而經過硝酸蝕刻後，其比電容值也有明顯的提升，對於Ni/Co=70/30系統，在掃描速率為10mV/s，從原先的51 F/g提升至237 F/g
，增加了4.6倍。綜合以上之結果，證明了酸蝕刻能有效地增加Ni-P與Ni-Co-P系統的比電容值，可將其應用在其他材料系統中。

關鍵字

超級電容 ； 無電鍍法 ； 軟性基板 ； 酸蝕刻 ； 鎳鈷磷膜

並列摘要

In this study, electroless Nickel and Nickel – Cobalt coatings were deposited on three kinds of flexible substrates (graphite paper, titanium foil, carbon fiber paper), and these coatings further etched in a 5M HNO3 solution to improve the electrochemical characteristics. Using a three-pole electrode system, cyclic voltammetry and charge-discharge curve were measured to calculate the specific capacitance, and electrochemical impedance spectroscopy (EIS) was used to analyze the electrochemical reaction mechanisms. In addition, the effects of Ni/Co ratios of Ni-Co-P system and etching time on the microstructure and the specific capacitance were explored in details. The results showed that nickel-phosphorus coating on the graphite paper substrate exhibited the highest specific capacitance (71 F/g) than the others (Titanium foil: 30 F/g; carbon fiber paper: 52 F/g) under the same plating conditions. After etching in HNO3 solution for 10s, the specific capacitance of Ni-P coating on graphite paper increased up to 335 F/g, in which the specific capacitance of Ni-P coating increase to 4.7 times as compared with the unetched one. Once the etching time was further increased, it did not significantly increase the specific capacitance. Microstructures analysis revealed that an appropriate etching time can effectively increase the surface area of Ni-P coatings and the prolonged etching time damaged the Ni-P coatings and finally the etched coatings peeled off. To deposit Ni-Co-P coatings on graphite paper, the pH value of electroless bath should be changed into 9. The specific capacitance value is not significantly improved by the addition of Co, but the corrosion resistance of the coating is improved. After etching in 5M nitric acid solution, it also significantly raised specific capacitance, for Ni/Co=70/30 system, at a scan rate of 10mV/s, from 51 F/g to 237 F/g. Based on the above the results, the acid-etching treatment effectively increased the specific capacitance of the Ni-P and Ni-Co-P system, it is expected that such method be applied to other material systems.

並列關鍵字

Supercapacitors ； Electroless Plating ； Nickel Oxide

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