Effect of concentration on electrochemical performance of ZrO2 /graphite felt in Vanadium Redox Flow Batteries

• Main Authors: Wei-Ning Hsieh, 謝偉寧
• Other Authors: I-Ming Hung
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/273qxb

碩士 === 元智大學 === 化學工程與材料科學學系 === 107 === The all-vanadium redox flow battery (Vanadium redox flow battery, VRFB) to be the center of attention because vanadium redox battery has the advantages of the higher depth of discharge, lower self-discharge, safety, and flexible design. it is largely characterized by their spatial separation of energy storage and energy conversion function, which cannot be attained in other secondary batteries based on solid-state active materials. Many companies have produced vanadium flow battery storage cabinets, also some countries have built a large range of energy storage systems for vanadium redox flow batteries. The purpose of this thesis is to modify the surface of graphite felt electrode material heat treatment, and acid-treated graphite felt, prepare different concentrations of zirconia precursor liquid for hydrothermal method, and grow zirconia nanoparticles on the surface of graphite felt. The effects of surface properties and electrochemical properties of the graphite felt were investigated by field emission scanning electron microscopy, X-ray diffractometer, cyclic voltammetry, and AC impedance analysis. The surface of the graphite mat of zirconia nanoparticle was generated by hydrothermal method, which improved the hydrophobicity of the graphite felt and improved the electrochemical properties of the graphite felt. The experimental results showed that the ΔEp value of the graphite felt after the modification was significantly reduced to 0.321~0.372V. and the current ratio is almost 1, the polarization phenomenon and reversibility of the graphite felt are improved. After the modification, the graphite felt has a higher current density, which significantly increases the electrochemical activity and reduces the polarization phenomenon.