The coolant used in a proton exchange membrane (PEM) fuel cell plays a vital role in regulating the fuel cell's temperature and removing waste heat. To ensure optimal performance, it is necessary that the coolant has a low dielectric constant and remains non-conductive.
Over time, ions from the materials used in the bipolar plates, radiators, and all coolant circuit components can migrate into the coolant and increase the electric conductivity. To counteract this, the coolant is passed over an ion exchange resin which captures said ions, therefore ensuring the coolant remains electrically non-conductive.
Additionally, to prevent large particles from blocking the channels in the bi-polar plates, a screen is integrated into the same housing.