MIT engineers have boosted the power output of direct methanol fuel cells (DMFCs) using a new material that offers several advantages, including lower cost than its traditional counterpart. DMFCs also have potential applications in other electrochemical systems, such as batteries.
The DMFCs currently on the market use and electrolyte material called Nafion, which is not only expensive but also permeable to methanol. That allows some of the fuel to seep across the center of the fuel cell, wasting fuel and reducing efficiency. Using a relatively new technique known as layer-by-layer assembly, the MIT researchers created an alternative to Nafion.
“We were able to tune the structure of [our] film a few nanometers at a time,” said Paula T. Hammond, Bayer professor of chemical engineering and leader of the team. This allowed the researchers to get avoid some of the problems associated with other approaches. The result is a thin film that is two orders of magnitude less permeable to methanol but compares favorably to Nafion in proton conductivity.
The work was reported in a recent issue of Advanced Materials by Hammond, Avni A. Argun, and J. Nathan Ashcraft. Argun is a postdoctoral associate in chemical engineering; Ashcraft is a graduate student in the same department.