Within the blooming hydrogen fuel cell industry, Koffman member ExoCell is developing and manufacturing a power source that uses the same molecules you’d find in the air, and at a fraction of the size of traditional cells, with far-reaching applications on the horizon.

Hydrogen fuel cells, like any electricity-generating power source, hinge on the flow of electrons creating an electric current. Fuel cells differ from batteries in that batteries store energy, while fuel cells actively convert chemical energy from a reaction between Hydrogen and Oxygen into electrical energy. 

Traditionally, hydrogen fuel cells have a heavy casing to house the inputs for reaction and seal off the fuel cell. These casing plates take up more than half the weight of the fuel cell, and limit its applicability for smaller machines like drones. ExoCell is developing a patented hydrogen fuel cell that they termed Thin Flexible Fuel Cell (TFFC),  which strips away this casing down to a thin and flexible sheet of the cell’s components, thin as a piece of paper

One square inch can produce about a watt of power, so theoretically a 10 inch x 10 inch sheet can produce 100 W, more than 30% of the energy needed to power a typical lightweight drone. 

The simplified design is only one factor that makes ExoCell’s technology unique in the fuel cell sector. Their TFFC utilizes oxygen from the surrounding air, so no forced fed oxygen supply is required for operation. As with all hydrogen fuel cells, hydrogen molecules (H2) are enter the fuel cell along with oxygen (O2). Hydrogen molecules are split by a catalyst into a positive hydrogen ion (H+) and an electron. The hydrogen ion then passes through a membrane, while the electron is directed around, creating a current. The electron then reunites with the protons and oxygen to form water. This, along with a bit of heat, are the only byproducts of the reaction.

Because of its stripped down design, the fuel cell’s cathodes (where water is formed) have maximum exposure to the ambient environment. Thus, the cell can get rid of the water produced and passively cool itself without the aid of liquid coolants, radiators or pumps. 

Because these fuel cells use hydrogen as a source of electrons instead of lithium, they cut out the harsh extraction required of lithium ion batteries. And because the only outputs of the reaction creating the power are energy, water and heat, they are a far cry from the heavy pollution of fossil fuels. The technology still has a long way to go to make a significant dent in fossil fuel use, but the ExoCell team is up to the challenge. 

Matt Mayer, graduate of the Stevens Institute of Technology with a bachelor’s degree in chemical engineering and PhD student in the NanoEngineering program at University of California San Diego, has been working on fuel cell technology since 2016 with Dr. Ronald Besser, former Professor and Chair of the Department of Chemical Engineering and Materials Science at Stevens Institute of Technology. The pair co-founded ExoCell, and have since grown to a core team of young businesspeople, physicists, mechanical and chemical engineers.

Mayer described the development of their new hydrogen fuel cell design as full of trial and error.

“[Back in 2016] The actual system itself was like a black box to us, so we didn’t really understand the mechanisms in too much detail with this new architecture,” Mayer recalled. “That was the first challenge, just understanding how the manufacturing process impacts the actual device. And then, once you actually understood how the different manufacturing processing steps can impact the device, the second challenge was scalability.” 

In March of 2021, Mayer and his team took ExoCell through the National Science Foundation I-Corps program at the Koffman Southern Tier Incubator. This program provides instruction on how to conduct proper customer discovery, along with a $3000 grant to do so. Initially, ExoCell was looking to focus on the market of drones for their fuel cell, but as Mayer recalled, I-Corps instructors Olga Petrova and Per Stromhaug pushed them to look beyond drones. The program opened the doors to the markets of transportation, defense, healthcare, wearable robotics and beyond.

ExoCell is continuing on to the National I-Corps program, accessing a $50,000 grant to conduct further customer discovery interviews and expand research on the best entry markets for them.

ExoCell will also be setting up operations at the Koffman Incubator as a member of the Southern Tier Clean Energy Incubator Program. Mayer notes that the wealth of resources such as Binghamton University facilities, laboratories and potential collaborators, drew his team to the incubator. ExoCell is continuing the development of their hydrogen fuel cell so that it can be integrated into basic technology and make the dive into the market.

The access to great advisors and resources that ExoCell has had would be fruitless without the determination that Mayer and his team maintain.  

“Stay persistent and patient,” Mayer advises to anyone trying to get their research or business off the ground. “Just continue to push, because you never know how close you actually are.”