MIT creates new material for fuel cellsMay 16, 2008Increases power output by more than 50 percent CAMBRIDGE, Mass.--MIT engineers have improved the power output of one type of fuel cell by more than 50 percent through technology that could help these environmentally friendly energy storage devices find a much broader market, particularly in portable electronics. The new material key to the work is also considerably less expensive than its conventional industrial counterpart, among other advantages. "Our goal is to replace traditional fuel-cell membranes with these cost-effective, highly tunable and better-performing materials," said Paula T. Hammond, Bayer Professor of Chemical Engineering and leader of the research team. She noted that the new material also has potential for use in other electrochemical systems such as batteries. 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. Like a battery, a fuel cell has three principal parts: two electrodes (a cathode and anode) separated by an electrolyte. Chemical reactions at the electrodes produce an electronic current that can be made to flow through an appliance connected to the battery or fuel cell. The principal difference between the two" Fuel cells get their energy from an external source of hydrogen fuel, while conventional batteries draw from a finite source in a contained system. The MIT team focused on direct methanol fuel cells (DMFCs), in which the methanol is directly used as the fuel and reforming of alcohol down to hydrogen is not required. Such a fuel cell is attractive because the only waste products are water and carbon dioxide (the latter produced in small quantities). Also, because methanol is a liquid, it is easier to store and transport than hydrogen gas, and is safer (it won't explode). Methanol also has a high energy density-a little goes a long way, making it especially interesting for portable devices. The DMFCs currently on the market, however, have limitations. For example, the material currently used for the electrolyte sandwiched between the electrodes is expensive. Even more important: that material, known as Nafion, is 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. 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," Hammond said, getting around 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. To test their creation, the engineers coated a Nafion membrane with the new film and incorporated the whole into a direct methanol fuel cell. The result was an increase in power output of more than 50 percent. The team is now exploring whether the new film could be used by itself, completely replacing Nafion. To that end, they have been generating thin films that stand alone, with a consistency much like plastic wrap. This work was supported by the DuPont-MIT Alliance through 2007. It is currently supported by the National Science Foundation. In addition, Hammond and colleagues have begun exploring the new material's potential use in photovoltaics. That work is funded by the MIT Energy Initiative. This Institute-wide initiative includes research, education, campus energy management and outreach activities, an interdisciplinary approach that covers all areas of energy supply and demand, security and environmental impact. For more information, please visit http://web.mit.edu/mitei/ Massachusetts Institute of Technology |
|||||||||||||||||||||
| Related Fuel Cell Current Events and Fuel Cell News Articles Toward home-brewed electricity with 'personalized solar energy' New scientific discoveries are moving society toward the era of "personalized solar energy," in which the focus of electricity production shifts from huge central generating stations to individuals in their own homes and communities. U of C chemists discover recipe to design a better type of fuel cell Fuel cells are often touted as one method to help decrease society's addiction to fossil fuels. But there is still a lot of work to be done before fuel cells will be ready for mass market to be used in transportation, home heating and portable power for emergencies. Ion Tiger fuel cell unmanned air vehicle completes 23-hour flight The Naval Research Laboratory's (NRL's) Ion Tiger, a hydrogen-powered fuel cell unmanned air vehicle (UAV), has flown 23 hours and 17 minutes, setting an unofficial flight endurance record for a fuel-cell powered flight. Smaller isn't always better: Catalyst simulations could lower fuel cell cost Imagine a car that runs on hydrogen from solar power and produces water instead of carbon emissions. While vehicles like this won't be on the market anytime soon, University of Wisconsin-Madison researchers are making incremental but important strides in the fuel cell technology that could make clean cars a reality. SRI to present hydrogen fuel safety research results at 2009 International Conference SRI International, an independent nonprofit research and development organization, announced today it will present new research identifying methods for designing safer structures in the future for hydrogen fueled vehicles, at the upcoming International Conference on Hydrogen Safety, Sept. 16 - 18, in Ajaccio-Corsica, France. Making more efficient fuel cells Bacteria that generate significant amounts of electricity could be used in microbial fuel cells to provide power in remote environments or to convert waste to electricity. Hydrogen Storage Gets New Hope A new method for "recycling" hydrogen-containing fuel materials could open the door to economically viable hydrogen-based vehicles. Growth Spurts: Berkeley Lab Researchers Record First Real-Time Direct Observations of Nanocrystal Growth in Solution The veil is being lifted from the once unseen world of molecular activity. Not so long ago only the final products were visible and scientists were forced to gauge the processes behind those products by ensemble averages of many molecules. Wastewater produces electricity and desalinates water A process that cleans wastewater and generates electricity can also remove 90 percent of salt from brackish water or seawater, according to an international team of researchers from China and the U.S. NRL's XFC UAS achieves flight endurance milestone The Naval Research Laboratory (NRL) has completed a successful flight test of the fuel cell powered XFC (eXperimental Fuel Cell) unmanned aerial system (UAS). More Fuel Cell Current Events and Fuel Cell News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||