Maximum power cold start mode of proton exchange membrane fuel cell

Successful and fast cold start is important for proton exchange membrane (PEM) fuel cell in vehicular applications in addition to the desired maximum power in any case. In this study, the maximum power cold start mode is investigated in details and compared with other cold start modes based on a multiphase stack model. It is found that for the maximum power cold start mode, the current density is generally kept at high levels, and the performance improvement caused by the membrane hydration and temperature increment may not be observable. Therefore, before the melting point, the performance drops continuously. The maximum power cold start mode could better balance the heat generation and ice formation, leading to improved cold start survivability than that in the constant voltage and constant current modes, with a fast start-up generally guaranteed. Once the survivability can be ensured, the initial water content needs to be higher for fast cold start, suggesting that over purging should be avoided. The maximum power mode is suggested to be optimal for PEM fuel cell cold start based on the modeling results.