Evolution of Characteristic Parameters in Fuel Cell Dynamic Response Under Durability Testing

This study conducted 1000-hour durability tests on four different single proton exchange membrane fuel cells (PEMFCs). The overall performance degradation of the cells was evaluated, and the evolution of two key dynamic response parameters—undershoot voltage and stabilization time—was analyzed during current density transients over time. The results showed that fuel cells with better mass transport properties consumed reactant gases more significantly in the upstream region during current transitions, leading to higher undershoot voltages. At higher current densities, the imbalance between gas supply and demand became more pronounced, further amplifying the undershoot. As the cell activation process progressed, partial internal performance improved, resulting in a decreasing trend in undershoot voltage. Stabilization time does not exhibit a clear correlation with load magnitude, but its increasing trend is closely related to the degradation of the cell's steady-state performance. These findings reveal a strong connection between dynamic response characteristics and performance decay, providing meaningful insights for the design, application, and health assessment of high-performance fuel cells.