In this study, conductive particles will spray- coated onto the surface of the MPL to function as micro pillar structures that has been proved to be able to significantly increase the performance of a PEMFC. Contrast with the previously used nano imprint technology , the new method is cheap,fast, and especially suitable for the fabrication of large-area electrodes.
The results show that a 30% increase in performance can be acquired by using 20um graphite particles. An increase of 57%, max power of 737mW/cm2 , may be achieved with irregular graphite flakes.
The understanding of the distribution and the development of the produced water inside the cathode are essential to associate the
performance increase with the microstructures. The electrode is dried gradually until a sharp increase in its impedance appeared, which indicates that the surface of the PEM begins to lose water. Then, i-v performance is measured through a cyclic test, i.e. , form a small load current to a large one and, then, buck to the small again. The performance improved with each cycle, because more and more water is produced along the test. A large performance ¡§jump¡¨ appearded at the 4th cycle only for the electrodes with the microstructure that indicates that the major reaction sites have shifted to the location of microstructures. It is concluded that, along with other evidence, a general water ¡§surface¡¨ exists and migrates form PEM towards MPL.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0827110-094828 |
| Date | 27 August 2010 |
| Creators | Liu, Bo-Yu |
| Contributors | Chorng-Fuh Liu, Peng-Sheng Wei, Long-Jeng Chen, Ming- San Lee |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0827110-094828 |
| Rights | not_available, Copyright information available at source archive |
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