A systematic investigation on the effects of Cu2+ contamination on the performances and durability of proton exchange membrane fuel cells

Durability problems are among the major obstacles that limit the large-scale application of polymer electrolyte membrane fuel cells (PEMFCs). Understanding the influence of metal cations on the performance of PEMFCs are of great significance for improving the durability. In this study, the membrane electrode assembly (MEA) is artificially contaminated using Cu2+ with different concentrations, and its influence as well as the mechanism on the activation, ohmic and mass-transport loss are systematically investigated upon 1200 h realistic driven cycle in combination with impendence analysis and physical characterization. In the beginning of life (BOL) tests, the rapid impact of Cu2+ is found by not only limiting the proton conductivity and oxygen transport in the ionomer, but also dramatically decreasing the activity of Pt/C on oxygen reduction reaction (ORR). After 1200 h durability tests (DT), those effects observed in BOL tests get significant and the degradation of membrane and carbon support come out. These insights into degradation behavior of various components in MEA in different time scales is instructive to understand the degradation mechanism and prolong the lifetime of PEMFCs.