Fuel cell materials studied for many kinds of environments

(Blacksburg, Va., Aug. 27, 2001) -- Fuel cell energy-producing efficiency can be competitive with or higher than an internal combustion engine and many times greater than batteries. Fuel cells can be smaller, lighter, and less costly than batteries for powering vehicles, with little or no environmental impact. Hydrogen is the key ingredient, but today's fuels -- diesel or regular gasoline, natural gas, or methanol -- can be used as the source of hydrogen protons to pass through a membrane to the oxygen side of the fuel cell, where electrochemical energy, water and heat are produced.

With all the options, as researchers continue to fine tune the materials used to process proton, it is critical to understand the proton exchange membrane (PEM) materials in great detail.

At the 222nd national meeting of the American Chemical Society, Aug. 26-30 in Chicago, Virginia Tech researchers will present information regarding relationships between the chemistry, morphology, and physical properties of PEM polymers.

James E. McGrath, chemistry professor and head of the PEM materials research group at Virginia Tech, explains that "the overall goal is to produce PEMS that perform well in a wide range of fuel cell environments."

Chemical engineering Ph.D. student Mike Hickner says, "We are developing the methodology to relate the membrane's performance in a fuel cell to its intrinsic polymer properties of microphase separation, water absorption, and most proton conductivity."

McGrath gives an example of one line of inquiry. "We vary the percent of the component that is an ion conductor to increase conductivity. However, that changes the solid state structure, or morphology. At some point, the material's water uptake shoots up and the polymer becomes a hydrogel -- not what you want in a fuel cell. We want good conductivity, but we want strength too. So we learn that you can't add more than 40 or 50 percent of the ion conductor without turning the material into a soft gel.

The group's presentation, "Chemistry-morphology-property relationships of novel proton exchange membranes for methanol fuel cells (FUEL 51)," is sponsored by the ACS Fuel Division. Hickner will present the research on Monday, Aug. 27, at 3:50 p.m. at the McCormick Place Lakeside Center, Room E258, Level 2,. Co-authors are postdoctoral associates Feng Wang and Yu Sueng Kim, B. Privovar and Thomas A. Zawodzinsky Jr. of Los Alamos National Laboratory, and McGrath. There will also be a poster presentation at 8:10 Monday evening in the Hyatt Regency Chicago Riverside Center.

Contact for more information:
James E. McGrath, University Distinguished Professor & Ethyl Corp Chair of Chemistry
office_phone: 1-540-231-5976
email: jmcgrath@vt.edu

---

---