Nuvera Fuel Cells

By Danielle Andre and contributing editors
Scott Blanchet, Platform Leader, Fuel Cell Development and
Amedeo Conti, Lead Engineer, Stack Design

As I was sitting in the monthly review of our Fuel Cell Stack Development team, a topic caught my ear. While the majority of information parlayed in this particular meeting falls under the category of intellectual property and therefore cannot be posted here (as you can imagine), there is some interesting work being done in regards to coolant that is fit to share.

Fuel cells create electricity through an electrochemical reaction between hydrogen on the anode side and oxygen on the cathode side. During the reaction heat is produced and a liquid coolant is required to control temperature. Managing the electrical conductivity of the fluids within the cell is extremely important in order to avoid current leakage and short circuiting. Deionized water typically has low electrical conductivity, making it an effective coolant for fuel cell stacks; the obvious downside to using water is that it freezes at typical winter temperatures. This is a sizable hurdle for fuel cells that are aimed at the automotive market.

Traditional (internal combustion engine) automotive systems are cooled with ethylene or propylene glycol, for just this reason. Glycol has a significantly lower freeze point than water, which is what allows our cars to start on those cold New England mornings. The issue with glycol is that it can have a high electrical conductivity rating, resulting in excessive corrosion within the fuel cell stack.

Nuvera has taken a serious look at the tradeoffs in the water vs. glycol debate: water is a low cost and effective solution, but is tricky when dealing with cold start applications. Glycol is only effective when used in conjunction with a deionizing filter which adds cost, but may help enable achievement of the holy grail in fuel cells – a timely cold start.
The glycol debate is nothing new inside Nuvera – our automotive stack, Andromeda™, is designed to be compatible with glycol, utilizing standard automotive parts. What we are determining now is the best glycol/water solution to produce the results we want, how to optimize our systems to run on glycol, and verifying the robustness of our systems when run on this glycol based coolant. If our findings resolutely show that glycol is the preferred coolant, you may see it in not only in our automotive products, but also in our PowerFlow™ system, maximizing performance in the forklift cold storage market.