Water transport mechanism within the electrode of a PEMFC

• Main Authors: Nai-wen Hsu, 許乃文
• Other Authors: Ming-San Li
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/10917677080496218277

碩士 === 國立中山大學 === 機械與機電工程學系研究所 === 99 === Water plays an important role in the operation of Fuel Cell. It determines where the electrochemical reactions should or should not occur. The purpose of this study is to investigate the transport characteristics of vapor through all components of an electrode and how they are related to the cell performance. In the transmit experiment of cell produce water which prove the level of water steam transmission characteristics has relative relations with the measurements of water transport in fuel cell. In a sum, the electrode with higher water steam transmission characteristics, the measurement of water transport will also be higher. From cell performance measure experiment, we can found that water steam transmission characteristics have the opposite relation with the concentration loss（mass transfer behavior）. As cell working on high current density, water will not clog easily under the great quality transmit electrode. Further, catalyst layer that has enough concentration would not cause the cell performance dismiss with the follow up reactions and it represents that cell performs batter with mass transfer. According to the experiment, PTFE in MPL with smaller amount has better performance to fuel cell. What the differences between the presentation of water as liquid state or gaseous state when it transmits in electrode? We can discover the rate of gaseous state water is faster compared to liquid state water when transmitting through MEA in a simple experiment. We assume that gaseous state of water is the first type within the electrode.