An engineering team at Washington University in St. Louis is looking into new ways to extend the lifespan of fuel cells.
The university is confident that fuel cells could someday generate electricity for nearly any device that is battery-powered. Typically using hydrogen (H2) as fuel and air as an oxidant, fuel cells are cleaner than internal combustion engines because they produce power via electrochemical reactions.
One issue that impacts the lifetime of the fuel cell is the oxidation, or breakdown, of its central electrolyte membrane. The process leads to formation of holes in the membrane and can ultimately cause a chemical short circuit.
The engineering team has developed a new way to take a look at the rate at which oxidation occurs. Using fluorescence spectroscopy inside the fuel cell, they are able to probe the formation of the chemicals responsible for the oxidation, namely free radicals, during operation. The technique could be a game changer when it comes to understanding how the cells break down, and designing mitigation strategies that would extend the fuel cell’s lifetime.
Yunzhu Zhang, a doctoral candidate and study co-author, said, “By using fluorescence spectroscopy in conjunction with an optical fiber, we can quantify the oxidative free radicals generated inside the fuel cell, which work to break down the membranes.”
Once they were able to observe the fuel cell’s inner workings, the researchers noticed that the weaker the light emitted from the fuel cell membrane, the greater the breakdown occurring from within.
Vijay Ramani, Roma B and Raymond H. Wittcoff Distinguished University Professor of Environment & Energy, explained, “The next step is to introduce antioxidant chemicals inside the fuel cell membranes, to see if they can reduce the rate at which these membranes break down.”
The School of Engineering & Applied Science at Washington University in St. Louis focuses intellectual efforts through a new convergence paradigm and builds on strengths, particularly as applied to medicine and health, energy and environment, entrepreneurship and security.