Dynamic response performance of proton exchange membrane fuel cell stack with Pt/C-RuO₂·xH₂O electrode

The dynamic response performance of a proton exchange membrane fuel cell (PEMFC) significantly affects its durability and reliability. Thus, the improvement of the dynamic performance of PEMFC has become the key for prolonging the PEMFC life in fuel cell vehicle applications. In this study, RuO₂·xH₂O is prepared by sol-gel method, and then sprayed onto catalyst layers to promote PEMFC dynamic response performance. The prepared RuO₂·xH₂O is characterized by TEM, which shows that the average particle size of RuO₂·xH₂O is 8 nm and that the particulates are uniformly distributed. A 10-cell stack is assembled using membrane electrode assembly (MEA) with and without RuO ₂·xH₂O. This stack is studied under various loading cycles and operating conditions, including different air stoichiometries, relative humidities, and loading degrees. Results show that the steady-state performance of the MEA with RuO₂·xH₂O is better than that in the MEA without RuO₂·xH₂O with a decreasing relative humidity from 80% to 20%. A slower and more unstable dynamic response of the MEA without RuO₂·xH₂O is observed as air stoichiometry and relative humidity decrease as well as the loading increase. Thus, RuO₂·xH₂O improves the dynamic response performance, indicating that RuO₂·xH₂O can buffer the voltage undershoot, improve the stability, and prolong the lifetime of the PEMFC stack.