A method of operating a fuel cell system includes providing a fuel cell stack containing a plurality of fuel cells and interconnects, and first and second ceramic side baffles located on opposing sides of the fuel cell stack, and applying an electrical potential to an outer surface of at least one of the first and the second ceramic side baffles, such that the electrical potential is equal to or more negative than a lowest potential of any interconnect in the fuel cell stack or any electrically conductive fuel cell stack component.