|
 |
The DMFC Challenge
Challenging
the Conventional
Wisdom
The demand for longer run-time is the driving force behind the development of fuel cells for portable devices. PolyFuel is committed to engineering hydrocarbon membranes to support the demands of portable applications. The result is a membrane that provides Direct Methanol Fuel Cells with the following design, fabrication and performance advantages relative to perfluorinated membranes.
PolyFuel's membrane enables smaller, lighter, lower cost and longer running systems. How do the other membranes compare?
 |
 |
Design Advantages: |
|
| 30 - 35% Less Catalyst |
|
| 30 - 35% Less Membrane |
|
| 30 - 35% Less Stack |
|
| 55 - 60% Less Cathode Water |
|
| 55 - 60% Less Water Recovery |
| Performance Advantages: |
| 30 - 35% Less Waste Heat |
|
| 30 - 35% More Run-Time |
| Operating Characteristics: |
| Higher Power: >90mW/cm2 at 0.4V |
|
| Lower Methanol Cross-Over:
40 mA/cm2 at open circuit |
|
| Lower Electro-osmotic Drag: 1.25 molecules per proton |
|
| Exceptional Durability: >5,000 hours |
| Benefits: |
| • Smaller, lighter systems |
|
| • Increased fuel efficiency for longer run-times |
|
| • Smaller and less complicated systems |
|
| • Longer product life |
|
|
|
|
Experimental Conditions
All tests performed on PolyFuel Direct Methanol Fuel Cell (DMFC) membrane of nominal 62 micron thickness using a Catalyst Coated Membrane (CCM) with an anode loading of 6 mg/cm2 Pt/Ru (4/2) and a cathode loading of 4 mg/cm2 of Pt. Tested in PolyFuel designed cell hardware of 22 cm2 active area using SGL 30BA and 30BB gas diffusion layers.
 |
|
Power: |
|
| Dry air at 2.5 stoichiometry, methanol at 5 stoichiometry, operating temperature 60°C; data obtained from a polarization curve performed on a Fuel Cell Technologies or Teledyne fuel cell test station. |
|
|
| Methanol Cross-Over: |
| Open circuit at 60°C. Current is obtained from polarizing the cathode under flowing nitrogen. |
|
| Electro-osmotic Drag: |
| Dry air at 2.5 stoichiometry, methanol at 5 stoichiometry. Calculated under load from the measured amounts of water condensed and CO2 content in the cathode air exhaust stream. |
|
| Durability: |
Running dry air at 2.5 stoichiometry and methanol at 5 stoichiometry at 200 mA/cm2 at 60°C. Duty cycle of
9 hours running and 3 hours off (cool to room temperature). Tests performed on an in-house test station using an Arbin battery cycler for control of current, duty cycle and reactant flows. |
|
All characteristics and functional product descriptions are based on PolyFuel
active system testing.
|
