Several researchers from the MIT succeeded in making a new kind of fuel cell. This one is a Direct Methanol Fuel Cell (DMFC), and it doesn’t need the prior extraction of hydrogen from methanol, but instead, as the name suggests, it extracts and uses it directly.
Until now, methanol fuel cells have had a great amount of loss due to their construction, because the membrane used, called “Nafion”, was permeable to methanol, allowing some of the fuel to seep across the center of the fuel cell. Among other disadvantages, this wastes fuel-and lowers the efficiency of the cell-because the fuel isn’t available for the reactions that generate electricity.
This new invention is practically a cheaper and more effective replacement for Nafion, whose manufacturing technology has been announced about 10 years ago. The new material is made by a layer-by-layer assembly technology. Paula T. Hammond, Bayer Professor of Chemical Engineering and leader of the research team, said that “We were able to tune the structure of [our] film a few nanometers at a time”. The result is a very thin film that is two orders of magnitude less permeable to methanol but is better than Nafion in proton conductivity.
To test their invention, the scientists coated a classic Nafion membrane with a film made by their new technique, and incorporated it in a methanol fuel cell. The results were astonishing: the new fuel cell developed 50% more energy than the old one!
The team is now exploring whether the new film could be used alone, completely replacing the old Nafion. To demonstrate that, they have generated thin films that stand alone, with a plastic wrap-like consistency.
The only weak point of this fuel cell model (associated with methanol) is that it produces a very small amount of CO2.
Update 23.10.08: You can find Paula talking about their discovery here.