Dimensionally Stable High Performance Membrane

Devices that employ fuel cell technology (such as vehicles, portable devices, and remote installations) require frequent startup/shutdown cycles. Surviving these cycles, particularly at freezing temperatures, will require the development of cost-effective, high-performance, proton-exchange membrane (PEM) materials. This project will develop a high performance membrane with excellent dimensional stability over a wide range of temperature and relative humidity. The new membrane will alleviate the water/ice expansion problem during the freeze/thaw process while simultaneously facilitating operation at low humidity and high temperature. This improved operability under suboptimal conditions will retard shorting and enhance the durability of the membrane. Phase I developed a dimensionally stable membrane that showed stellar mechanical stability compared to Nafion®, with a creep rate at least one order-of-magnitude lower. The feasibility of the concept was demonstrated in membrane formation, membrane-electrode assembly fabrication, fuel cell performance, and freeze/thaw stability. Phase II will develop alternative membrane fabrication processes to lower cost and increase performance, and demonstrate freeze/thaw stability and scalability with both 50 cm2 fuel cells and short stacks (3-5 cells, 100-200 cm2, 250-500W). Commercial Applications and other Benefits as described by the awardee: The new PEMs should be readily applicable to fuel cells employed in vehicles, portable devices, and remote installations. Compared to conventional ionomer membranes, the new membrane should provide higher reliability, longer life, and wider relative humidity and temperature operating ranges. Its low projected fabrication cost of ~ 2 ¢/cm² should enhance commercialization possibilities.