The Pentagon recently announced significant research funding for topics important to national defense being investigated at universities around the nation. Chunsheng Wang, assistant professor of Chemical Engineering with the Center for Manufacturing Research, has been awarded about $350,000 by the U.S. Department of Defense to develop high power membrane fuel cells for military applications.
"There are two ways to detect enemy targets on the battlefield — by noise and heat," explains Wang. "A vehicle using a combustion system is noisy and hot. A vehicle powered by a fuel cell produces relatively little noise and heat."
Wang specializes in researching the type of fuel cell that would optimize the performance of Army vehicles. He works with PEMFCs, or proton exchange membrane fuel cells, which currently operate at about 80 degrees Celsius, a little less than the temperature of boiling water and low enough to be practical for autos, laptops and other portable devices. The current version also works well in hybrid autos, but users are for the most part limited to using pure hydrogen.
"Current PEM fuel cells are constructed with very expensive metals such as platinum, making the cost too high for practical use," says Wang. "If we can raise the operating temperature, we can use other materials that will result in lower costs. Increasing the temperature also means we can produce a faster reaction, which translates into more power to the vehicle."
The ideal range for operating temperature is 120-150 degrees Celsius, which is relatively low compared to other types of fuel cells that operate at numbers as high as 250 degrees Celsius.
Since the fuel cell is a device that creates electricity from a chemical reaction between hydrogen and oxygen, leaving only water as a byproduct, there is also an issue of what form the water needs to be in to create the best performing Army vehicle.
Wang explains that a fuel cell that operates below 100 degrees Celsius produces liquid water as a byproduct, water that can block the reaction needed in a high-powered vehicle. If the fuel cell operates at a temperature above 100C, the water can be easily expelled as a vapor.
"This research can not only lead to a more powerful, stealthy vehicle for the Army, but also bring us closer to producing a more efficient, cost-effective electrical vehicle for personal use," says Wang.
The Department of Defense is also interested in Wang's fuel cell adaptations because soldiers on the ground are wearing more and more equipment in the field that requires power sources. For instance, night vision equipment requires batteries that have to be recharged in the field, an inconvenient maneuver at best under battle conditions.
Wang is addressing the issue by developing a fuel cell that can charge the battery, and hopes to create a cell that will totally replace the battery. The wearable fuel cell would be smaller and lighter than current batteries.
Wang's research will be funded through a program called "Defense Experimental Program to Stimulate Competitive Research." For the three-year project, the state of Tennessee will match 50 percent of the funds, raising the research dollars to over a half million dollars.
Tennessee Tech and Vanderbilt were the only two Tennessee universities to be awarded grants through the program. TTU was chosen to submit two of only five proposals sent by the state for DOD review this year.