Advances in the design and control

Advances in the design and control of reactant flows across a PEM fuel cell stack are essential to improve durability/stability in commercial applications [6,7]. In general, reactants such as hydrogen and oxygen should be excessively supplied to PEM fuel cells to prevent reactant starvation and to minimize the reactant water produced, so as to avoid the flooding that hinders reactants from reaching the reaction sites inside the cell. In addition, higher reactant flow rates result in better fuel cell performance by keeping the reactant concentration high (lower fuel utilization).