Relationships between water management, contamination and lifetime degradation in PEFC

Water management in PEFCs is an important parameter to optimize for peak pe rformance. Its importance is further emphasized by data obtained with impur ity-contaminated cells and from life tests carried out using several cell h umidification levels. The results show the detrimental effects of impuritie s on several key cell performance loss types (including kinetic, ohmic and mass transport losses). Furthermore, an improper water balance (either too wet or too dry) has a long term effect on cell degradation rates. Efficient and practical water management strategies to reduce the detrimental effect s of impurities and exposure to excess water or dryness are also reviewed.