Corrosion Resistant Bipolar Plates for PEM Fuel Cells

91 Corrosion Resistant Bipolar Plates for PEM Fuel Cells--Physical Sciences Inc., 20 New England Business Center, Andover, MA 01810; (508) 689-0003 Dr. Michael C. Kimble, Principal Investigator Mr. George E. Caledonia, Business Official DOE Grant No. DE-FG02-97ER82454 Amount: $74,989 Fuel cells offer a potential replacement for the internal combustion engine in vehicles because they are clean, energy efficient, and can use more than one type of fuel. For this reason the Partnership for a New Generation of Vehicles, in which the Department of Energy plays a key role, is particularly interested in supporting research to develop corrosion-resistant bipolar plates, which are key components in proton exchange membrane fuel cells. Traditionally, graphite bipolar plates have been used in fuel cells to separate each cell in a stack, and machined or molded flow fields (channels) are placed in these plates to allow the hydrogen and air to mix and react with other materials. Not only are these flow fields costly to manufacture, but the bipolar plates themselves also contribute to about 75 percent of the weight of the stack of fuel cells. The high cost and large mass and volume of these graphite bipolar plates prevent the proton exchange membrane fuel cell from currently being commercialized for vehicular applications. To address these problems, Phase I will be devoted to constructing thin and lightweight bipolar plates from aluminum that has been electrodeposited with metal layers to impart corrosion resistance. Bipolar plate corrosion will be reduced through the control of ductility, tensile strength, porosity, and grain size, among other properties in the desposition process will be optimized to. The mechanical properties of the deposited metal layers will be optimized to obtain high electrical conductivity while maintaining similar coefficients of thermal expansion between the aluminum and coating. This will allow thin metal bipolar plates to be easily stamped for channels, coated, and incorporated in the proton exchange membrane fuel cell stack. A Phase II project will examine longer durability testing of these bipolar plates. Commercial Applications and Other Benefits as described by the awardee: This process for fabricating bipolar plates uses inexpensive materials, uses established electrodeposition technology, and has high-volume manufacturability capabilities using low-cost capital equipment. These attributes improve the chances for successful introduction of vehicles powered by fuel cells in the marketplace._