Experimental Studies of Catalyst Coated Membrane Method within large Membrane Electrode Assomblies of PEMFC
Date Issued
2006
Date
2006
Author(s)
Lin, Ji-Chieh
DOI
zh-TW
Abstract
The membrane electrode assembly (MEA) and the stacks play an important role on the performance of a proton exchange membrane fuel cell (PEMFC). In this work, MEAs were fabricated by catalyst coated substrate method and by catalyst coated membrane method. Experiments were carried out in this work to investigate the influence of operating conditions on the performance of Mea. The operating parameters include the catalyst loading, temperature of the cell, temperature of hydrogen humidification, H2/O2 ratio, etc.
The membrane electrode assembly was fabricated by coating the catalyst (Pt black) on the surface membrane directly to improve the continuity of interface between the catalyst film and the membrane. Nafion117 was adopted as the membrane electrode assembly with the active area of 140 mm x 140 mm. The optimum performance of the MEA made in this work was found to be 36.04 W at 0.644 V and 285.7 mA cm-2, corresponding to the conditions as: Pt loading at the cathode and at anode side is 0.6 and 0.5 mg cm-2, respectively; cell temperature of 50℃, and the hydrogen humidification temperature of 90℃.
The single PEMFC and the two-cell stack type PEMFC were tested in this study to evaluate the correlation between the current density and the voltage. Experimental results show that as for the single-fuel PEMFC, the power output of MEA fabricated by catalyst coated substrate method is higher than which made by catalyst coated membrane method, to the extent around 30%. The system was operated for 8000 min continuously, with the current lowered down only about 2%. On the other hand, the power out of the two-cell stack type PEMFC per cell is slightly lower than that of the single cell system, owing to water choking inside the channel. Since the flow pattern of reactant gases in the two-cell stack is more complex than that in the single-cell unit, the heat insulation should be designed specifically to avoid the moisture condensation.
Subjects
質子交換膜型燃料電池
膜電極組
直接塗佈
PEMFC
MEA
CCM
nafion117
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-95-R93522121-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):8b0f82249806ab4fcc5be7629ae04e42