Development of a Novel Redox Flow Energy Storage Battery
| Autor: | CHEN,TSUNG-SHENG, 陳宗聖 |
|---|---|
| Rok vydání: | 2019 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 108 The redox flow battery (RFB) is an electrochemical system which electrolytes stored in two tanks were pumped and circulated through the stack where an electrochemical reaction occurred, and powering the redox flow battery from the electrical energy turns it into chemical energy. The RFB has been developed in large scale energy storage systems (KWh-MWh) during the last decade and has numerous advantages over other batteries, such as high storage capacity and efficiency, long operating life, safe, environmental friendly, etc. RFB has wide range applications, such as renewable energy( wind power and solar power), photovoltaic, distributed power generator, back-up power for military purpose, un-interrupted power (UPS) for cellular phone station, commercial buildings and so on. The key materials of RFB system include ion exchange membrane, electrode, electrolyte, and flow channel. The RFB’s energy storage density is decided by the characteristics of these key materials, also there is an important relationship with each other. Among them, all-vanadium redox flow battery (All-VRFB) is widely used due to its fast response time, low discharge capacity, flexible design, non-flammable and non-explosive properties. However, due to the high cost, key materials in high-concentration acid environment are susceptible to acid etching and precipitation of vanadium salts are limited by commercial operation. Therefore, looking for cheaper electrolytes and dedicating to the upgrading of key materials will not only improve battery efficiency, but also further reduce the cost of energy storage batteries. This will be the most important breakthrough bottleneck for the sustainable development of renewable energy in the future. In this study, the first part is the development of a new semi-vanadium/iodine redox flow battery (semi-V/I RFB). Iodine/vitamin C solution can be as active electrolyte to replace vanadium electrolytes. The semi-V/I RFB shows a good performance with C-TiO2-Pd modified electrode, also that can obtain higher battery efficiency in V/I-RFB system (Coulomb efficiency: 96%, Voltage efficiency: 87%, Energy efficiency: 83%). energy efficiency: 80%), which has great development potential. The second part is the development of key materials for the redox flow battery of new iron salt (new V/Fe RFB). The use of vanadium sulphate and ammonium ferrous sulfate were as the positive and negative electrolytes to set up a V/Fe RFB, which improves the electrode, flow channel and ion exchange membrane, respectively. The RFB composed of C-TiO2-Co-P composite electrode, staggered flow channel and Nafion117-SS (N-117/ SiO2-SO3H) membrane has better cell efficiency (Coulomb efficiency: 96%, voltage efficiency: 84%, energy efficiency: 80%). The third part is the effectiveness evaluation of the charge and discharge cycle life of RFB systems. Using the Nafion117-SS membrane as the separation membrane, the C-TiO2-Pd or C–TiO2–Co–P as the electrode for iodine or iron electrolyte, and staggered flow channels in a single semi-V RFB, excellent cyclic performances in a charge–discharge durability test of 50 cycles could be achieved. The semi-V RFB can reduce the amount of vanadium salt and acquire a maximum coulomb efficiency; consequently, by reducing the cost it thereby creates an unlimited development potential for the energy storage systems. KEYWORDS: all-vanadium redox flow battery; vanadium/iodine redox flow battery; vanadium/iron redox flow battery; composite electrode; sol-gel; electroless plating |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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