Transient response of performance in a proton exchange membrane fuel cell under dynamic loading

•Transient responses of fuel cell under various operation conditions are studied.•Fuel cell after activation can be loaded from 0 to 1.5 A cm−2 within 1 s.•Dehydration in membrane results in large discrepancies in dynamic performance.•Load strategies are suggested for fuel cell at start-up with a large step-current. The capability of proton exchange membrane fuel cell to be loaded successfully in a short time is an important consideration for its evaluation as a reliable power source in different applications. In this study, the transient response of the proton exchange membrane fuel cell under various operation states is analysed. The output power is increased by applying a step current, and the response voltage, as an indicator of the dynamic performance, is recorded. The experimental results show that the fuel cell cannot be successfully loaded at start-up when the current step is increased from 0 A cm−2 to 0.8 A cm−2. It can be loaded successfully with a step current density of 1.5 A cm−2 after activation. The dehydration of the membrane can result in large discrepancies in the dynamic performance. A state-of-the-art proton exchange membrane fuel cell should show favourable response to a high step current when loaded smoothly to a high-power output within a short time. The study can provide guideline for the design and control of the dynamic loading in proton exchange membrane fuel cell.