Analysis of Shunt Currents and Associated Corrosion of Bipolar Plates in PEM Fuel Cells
Shunt currents are influenced by cell voltage, cell number, manifold ohmic resistance, product water/coolant purity, and the charge transfer resistance of bipolar plate surfaces to electrolysis. In this work, electrochemical characterizations were performed to estimate these characteristics under relevant operating conditions. A numerical solution of the shunt currents is presented, and the distribution of corrosion and hydrogen evolution are described. The same calculations would apply to PEM electrolyzers used for hydrogen and oxygen production. With some adjustment, similar calculations may also be applied to other electrochemical system with common electrolyte channels, such as flow-batteries and other devices where an electrolyte manifold experiences voltage gradients.