燃料電池不銹鋼雙極板之開發

• Main Authors: Lin Ming Chenh, 林明政
• Other Authors: 白清源
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/25343599567059357607

碩士 === 國防大學中正理工學院 === 兵器系統工程研究所 === 96 === This study tries to improve the surface roughness and the corrosion resistance of the commercial stainless steel SS316 by the electropolishing technology. The polished steel is anticipated to replace the graphite used as bipolar plates of fuel cells at present. At frist, we tried to formulate various electrolytes and electropolish the steel in these solutions. The surface roughness and morphology of the polished steels was examined and compared to select suitable electrolyte components. After the decision of the components of electropolishing solution, the Taguchi method was used to investigate the effects of operating parameters and electrolyte concentrations on the surface characteristic of the polished steel. Moreover, the most appropriate polishing conditions were designed and the electrolyte compositions were optimized by employed the Taguchi means. The ANOVA (analysis of variance) and contribution analysis were also applied to analyze the better polishing operating parameters in all factors. After the analyses, the verified experiment was performed. Some electropolished steels with two predicted characteristics, (1) low surface roughness (Ra and Rmax) and (2) low corrosion current, were chosen as estimated samples among all of the polishing specimens. Interfacial contact resistance and electrochemical performance of these samples were tested, and their compositions of the passive films were analyzed by XPS. The results of these examinations were used to evaluate the performance of SS316 steels electropolished under the conditions designed by Taguchi method, when the polished steels were used as the fuel cell’s bipolar plate. The experimental results show that adding proper contents of glycerol in selected standard electrolyte, the electropolished SS316 steels possess very superior surface characteristics. While the Taguchi method was subsequently employed to design an optimum experimental conditions, the surface roughness of SS316 is obviously further reduced to the level of Ra = 0.023 μm and Rmax = 0.154 μm, and the corrosion resistance of this steel can be available improved to approach the corrosion current of graphite. It shows that the surface-modified SS316 steels by an electropolishing process have a potential for the applications in the PEMFC fuel cell’s bipolar plate.