Author: Emily Flinchum

Supported by a new grant from U.S. Department of Energy Advanced Research Projects Agency-Energy (ARPA-E), a Johns Hopkins group is developing a high-density hydrogen fuel cell system that could be used in a variety of transportation modes, from jets and trains to ships and electric vehicles.

Chao Wang, associate professor in the Whiting School of Engineering’s Department of Chemical and Biomolecular Engineering, received the grant as part of the ARPA-E’s Pioneering Railroad, Oceanic, and Plane ELectrification with 1k energy storage systems (PROPEL-1K) program, aimed at developing advanced energy storage systems for sustainable transportation use. The PROPEL-1K program is set up in two phases, with Wang’s project in Phase I. Once the concept is proved in lab scale, it’s ARPA-E’s intension to support scaling up of the technology in Phase II.

“Scaled up, our system could provide clean, easy-to-transport power to off-grid sites for extended periods with minimal downtime, which could be a game changer,” said Wang, director of the Nano Energy Laboratory and an expert in electrochemical energy conversion and storage. “Down the line, it could pave the way to wider adoption of renewables in heavy-duty transportation systems.”

Transportation is the largest contributor to greenhouse gasses in the United States, with aircraft, trains, and ships generating approximately 13% of the sector’s annual emissions. PROPEL-1K works to create technologies that will electrify flights traveling as far as 1,000 miles with up to 100 people, all North American railroads, and all vessels operating exclusively in U.S. territories.

Wang’s project will use methylcyclohexane, a compound that can absorb and release hydrogen, to create a fuel cell that will hold greater amounts of energy than those currently used. This new system will also allow for the recycling of the methylcyclohexane. And when the system needs to be replenished, it can be refilled rapidly via pumping, in about 10 minutes.

“This fuel-cell technology would be a stable, low-toxicity, scalable fuel source that eliminates the need for costly pressurization and liquefaction, which currently limits the broad use of hydrogen. But that is just part of our goal. Ultimately, we hope that this innovative energy storage technique will push forward the electrification of railroad, ship, and other travel,” Wang said.