Water management in novel direct membrane deposition fuel cells under low humidification
| Autor: | Matthias Breitwieser, Simon Thiele, Michael Schulz, Jonathan Schock, Roland Zengerle, Riko Moroni, Franz Pfeiffer, B. Schillinger |
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| Rok vydání: | 2016 |
| Předmět: |
Renewable Energy
Sustainability and the Environment Chemistry Membrane electrode assembly Analytical chemistry Energy Engineering and Power Technology Proton exchange membrane fuel cell 02 engineering and technology Electrolyte 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Cathode 0104 chemical sciences Anode law.invention ddc:380 Fuel Technology Membrane Chemical engineering law PEMFCs Direct membrane deposition Neutron radiography Water management Back diffusion 0210 nano-technology Polarization (electrochemistry) Power density |
| Zdroj: | International Journal of Hydrogen Energy. 41:11412-11417 |
| ISSN: | 0360-3199 |
| Popis: | Polymer electrolyte membrane fuel cells (PEMFCs) fabricated by direct membrane deposition (DMD) were shown to work even at dry conditions without significant deterioration of the membrane resistance. Here, in situ neutron radiography is used to investigate the water management in those fuel cells to uncover the phenomena that lead to the robust operation under low humidification. A constant level of humidification within the membrane electrode assembly (MEA) of a DMD fuel cell is observed even under dry anode operation and 15% relative humidity on the cathode side. This proves a pronounced back diffusion of generated water from the cathode side to the anode side through the thin deposited membrane layer. Over the entire range of polarization curves a very high similarity of the water evolution in anode and cathode flow fields is found in spite of different humidification levels. It is shown that the power density of directly deposited membranes in contrast to a 50 μm thick N-112 membrane is only marginally affected by dry operation conditions. Water profiles in through-plane direction of the MEA reveal that the water content in the DMD fuel cell remains steady even at high current densities. This is in contrast to the N-112 reference fuel cell which shows a strong increase in membrane resistance and a reduced MEA water content with raising current densities. Thus this new MEA fabrication technique has a promising perspective, since dry operation conditions are highly requested in order to reduce fuel cell system costs. |
| Databáze: | OpenAIRE |
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