Another Fuel Cell Breakthrough, But With A Twist

Fuel cell news generally gets short shrift from CleanTechnica readers. Pretty much every announcement about “fool cells” is greeted by a collective “ho hum.” That’s usually because fuel cells in private vehicles just don’t seem to create a spark of interest for most EV advocates. However, there are other types of vehicles — usually heavy cargo haulers — that may benefit from fuel cell technology while we wait for the low-cost, high-power batteries of the future to arrive.

Artistic representation of the pH-gradient enabled micro-scale bipolar interface. The two layers that make up the interface are covering the third bottom layer, which is the electrode with palladium particles on it. The submarine and drones are envisioned applications of the direct borohydride fuel cell which incorporates the PMBI. Credit: McKelvey School of Engineering

Researchers at Washington University in St. Louis announced in a study published in Nature Energy on February 25 that they have achieved a rather remarkable breakthrough in fuel cell technology — a device with double the voltage of commercial fuel cells available today. The explanation is rather jargon heavy, so bear with us as we parse the report in Science Daily.

“The pH-gradient-enabled microscale bipolar interface is at the heart of this technology,” says professor Vijay Ramani. “It allows us to run this fuel cell with liquid reactants and products in submersibles, in which neutral buoyancy is critical, while also letting us apply it in higher-power applications such as drone flight.”

The fuel cell created by the research team uses an acidic electrolyte at one electrode and an alkaline electrolyte at the other electrode. It is vital to keep the two separate. The secret sauce in this case is the PMBI membrane, which is thinner than a strand of human hair. Using membrane technology developed at the McKelvey Engineering School, the PMBI can keep the acid and alkali from mixing, forming a sharp pH gradient and enabling the successful operation of this system.

“Previous attempts to achieve this kind of acid-alkali separation were not able to synthesize and fully characterize the pH gradient across the PMBI,” said Shrihari Sankarasubramanian, a research scientist on Ramani’s team. “Using a novel electrode design in conjunction with electroanalytical techniques, we were able to unequivocally show that the acid and alkali remain separated. This is a very promising technology, and we are now ready to move on to scaling it up for applications in both submersibles and drones.”

See, we issued a jargon alert and now you know why. Lead author and doctoral candidate Zhongyang Wang adds, “Once the PBMI synthesized using our novel membranes was proven to work effectively, we optimized the fuel cell device and identified the best operating conditions to achieve a high-performance fuel cell. It has been a tremendously challenging and rewarding pathway to developing the new ion-exchange membranes that has enabled the PMBI.”

Okay, so what’s the twist? Electric airplanes will be a critical piece of the transition away from fossil fuels that must take place if the world is to significantly lower the amount of carbon dioxide pumped into the atmosphere from the transportation sector. CleanTechnica has published a number of stories about the advent of electric passenger aircraft. As exciting as the news about electric airplanes is, they are limited in their range at the present time to a few hundred miles at most. How might high-voltage fuel cells change that scenario? Whatever your feelings about fuel cells, the prospect of longer range electric aircraft has to be good news.