In this thesis, a long-term operation direct methanol fuel cell (DMFC) stack with no performance decay is developed and improved. In a traditional passive portable DMFC, the Methanol solution is storage at anode Reaction chamber. The performance will drop after a short period due to the concentration of Methanol solution becoming lower (about 1.5M). Although High concentration of Methanol solution could increase the operation time, but it will couse crossover to poison the cathode Pt particle, and it is unable to keep long-term operation stably either.
In order to achieve long-term operation stably, to maintain the concentration of methanol solution in the anode chamber will be very important. In our fuel supply stack, there are two chambers in the stack to storage methanol and water, and we could control the supplying rate by adjusting the diffusion area to control the diffusion rate of methanol and water. And the methanol solution deliver to anode reaction chamber by cotton tube.
If the anode reaction chamber is filled with 1.3¢W, 2M methanol solution and without any fuel supply, operating on the 185mA constant current (82.2mA/cm2 ). The results shows that the performance begin decay about after 15minutes. If the appropriate amount of methanol and water is supplied, the performance can be steady in a long-term operation.
But if supply too much methanol solution, the concentration in the anode reaction chamber will rise up, and the high concentration will cause crossover poised the cathode catalyst, and the performance will decay. If supply rate not enough, the concentration in the anode reaction chamber will become lower, and the performance will decay after long-term operation. In this study, based on operate current and the rate of evaporation of methanol solution, to supply appropriate supplying rate and concentration of methanol solution to anode reaction chamber, could keep the performance in a steady output.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0905111-110349 |
| Date | 05 September 2011 |
| Creators | Huang, Guo-Sheng |
| Contributors | Ming-San Lee, Peng-sheng Wei, Chung-Fu Liu, Long-Jeng Chen |
| 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-0905111-110349 |
| Rights | user_define, Copyright information available at source archive |
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