Study of Electrode Modification for All Vanadium Redox Flow Battery

• Main Authors: Yu-chen Shih, 施又甄
• Other Authors: Chen-hao Wang
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/95kxh3

碩士 === 國立臺灣科技大學 === 材料科學與工程系 === 103 === High surface area, high conductivity and porous structure graphite felt materials are common choice of all vanadium redox flow battery. However, graphite felt materials have serious problems of their insufficient electrochemical activity and low electrochemical reversible ability. In order to overcome those problems, this study uses (1) acid treatment activation method and (2) microwave-assisted hydrothermal method as activation methods to solve these problems. In the first part, the graphite felt was immersed in acid solution which was mixed with 60 mL of sulfur acid and 20 mL of nitric acid, and subsequently it was transferred into a Teflon-lined autoclave reactor and was heated at 140oC. Afterwards, the graphite felt was heated at 450oC in oxygen atmosphere. In the second part, the graphite felt was immersed in 0.049 M melamine of nitric acid solution, and it was treated by microwave-assisted hydrothermal method at various temperatures of 120oC, 140oC and 160oC. By using the acid treatment and the microwave-assisted treatment, the graphite felt electrodes show the enhanced electrochemical activity and the highly reversible redox reaction. By using acid-treatment, the coulomb efficiency, the voltage efficiency and the energy efficiency of the graphite felt can reach 94.8%, 81.7% and 77.1%, respectively. By using the microwave-assisted treatment, the graphite felt can also reach high coulomb efficiency, voltage efficiency and energy efficiency of 94.9%, 89.8% and 85.1%, respectively.