Electrochemical Assessment of the Degradation of Membrane Electrode Assemblies Prepared with Electrodes made by Filter-Transfer Method

• Main Authors: Po-Chung Chen, 陳柏仲
• Other Authors: Yu-Chen Chang
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/11144110933873318668

碩士 === 元智大學 === 化學工程與材料科學學系 === 95 === Fuel cell is an electrochemical device that transforms chemical energy of the fuel used to electricity at high efficiency. The durability of polymer electrolyte membrane fuel cells (PEMFCs) is a major barrier to the commercialization of these systems. This work deals with fundamental electrochemical aspects of polymer electrolyte fuel cell research. Various electrochemical analyses were applied to assess and understand the degradation mechanisms for MEA samples prepared with electrodes made by filter-transfer methods. This study focuses on degradation rate versus transfer ratio or filtration time used in electrode preparation. At an operating condition of 50% humidity and a cell temperature of 70℃, polarization curve, electrochemical impedance spectroscopy (EIS), and Cyclic Voltammetry (CV) measurements were performed before and after a 100-hour continuous operation. The results showed that the MEA with the highest transfer ratio or a 95-minute filtration time has the highest Pt utilization, and decay or degradation rate, but not the highest resistances overall. In other words, a higher transfer ratio or Pt utilization does not necessarily mean lower decay rate or better durability. Distinctly different oscillatory behaviors were observed for all the four MEA samples made with electrodes of different transfer ratio studied here.