Abstract
Water management is a significant challenge in portable fuel cells and particularly in fuel cells with air-breathing cathodes. Liquid water condensation and accumulation at the cathode surface is unavoidable in a passive design operated over a wide range of ambient and load conditions. Excessive flooding of the open cathode can lead to a dramatic reduction of fuel cell power. We report a novel water management design based on a hydrophilic and electrically conductive wick in conjunction with an electroosmotic (EO) pump. A prototype air- breathing fuel cell with the proposed water management design successfully functioned under severe flooding conditions, including ambient temperature 10ºC and relative humidity 80 %, for up to 6 h without any observable cathode flooding or loss of performance.