Preparation of Highly Porous RuO2-Ta2O5/Ti Electrodes by Utilizing Poly(isobutyl methacrylate) for Supercapacitors

• Main Authors: Chun-Ching Huang, 黃淳靖
• Other Authors: Jiin-Jiang Jow
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/es375z

碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系博碩士班 === 102 === Preparations of high loading and high capacitance of the RuO2-Ta2O5/Ti electrodes for supercapacitors were studied in this work. The surface microstructure and specific capacitance of the electrodes prepared with various coating solutions containing different solvents such as Butyl cellosolve (BCS) and Diethylene glycol monobutyl ether (DB), were investigated. In addition, Poly(isobutyl methacrylate) (PiBMA), as a pore promoter during the sintering, was used to improve the formation of pores and increase the specific capacitance of the electrodes. The electrochemical behaviors of the electrodes were examined by cyclic voltammetry (CV), while the characteristics of the electrodes were measured by field emission scanning electron microscope (FE-SEM), X-ray diffractometery (XRD) and Auger electron spectroscopy (AES) , respectively. The results show that the cracks on the electrode surface and specific capacitance significantly depend on the composition of the coating solutions. Coating solutions with higher volatile solvents are favorable for the crack generation. High specific surface area electrodes are obtained by using coating solution containing BCS or DB solvent. It is also found that fine cracks on the islands of the coatings make an important contribution to the specific capacitance of the RuO2-Ta2O5/Ti electrodes. The specific capacitance decreases with increasing the loading of active substances on the electrodes due to the decrease of the cracks in the thick coating layer. On the other hand, highly porous RuO2-Ta2O5/Ti electrodes were prepared by using the coating solution containing BCS solvent and PiBMA. The results show that there are a large quantity of pores (0.3-0.6μm diameter) on the electrode surface. The specific capacitance (Csp) of the porous electrodes with loading of 4.3mg cm-2 is 341F g RuO2-1 at scan rate of 50mV s-1, which is 32% higher than those without the PiBMA. A maximum the RuO2-Ta2O5 loading amount of 6.7mg cm-2 with a specific surface capacitance (Cssp) value of 1.6F cm-2 was obtained. The results of cycle life test show that the decay of specific capacitance is 3.2%, indicating the high electrochemical reversibility and stability of the porous RuO2-Ta2O5/Ti electrodes.