Active water management at the cathode of a planar air-breathing polymer electrolyte membrane fuel cell using an electroosmotic pump

• Published in: Journal of power sources Vol. 195; no. 11; pp. 3640 - 3644
• Main Authors: Fabian, T., O’Hayre, R., Litster, S., Prinz, F.B., Santiago, J.G.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.06.2010; Elsevier
• Subjects: Applied sciences; Cathode flooding; Cathodes; Design engineering; Direct energy conversion and energy accumulation; Electric power generation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Flooding; Fuel cell system design; Fuel cells; Micro-fuel cell; Portable-power; Pumps; Water management; Wick; Wicks; Cathode flooding; Micro-fuel cell; Wick; Portable-power; Fuel cell system design; Polymer electrolytes; Cathode; Flooding; Proton exchange membrane fuel cells; Aerobic technology; Fuel cell; Planar technology
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2009.12.025

In a typical air-breathing fuel cell design, ambient air is supplied to the cathode by natural convection and dry hydrogen is supplied to a dead-ended anode. While this design is simple and attractive for portable low-power applications, the difficulty in implementing effective and robust water management presents disadvantages. In particular, excessive flooding of the open-cathode during long-term operation can lead to a dramatic reduction of fuel cell power. To overcome this limitation, we report here on a novel air-breathing fuel cell water management design based on a hydrophilic and electrically conductive wick in conjunction with an electroosmotic (EO) pump that actively pumps water out of the wick. Transient experiments demonstrate the ability of the EO-pump to “resuscitate” the fuel cell from catastrophic flooding events, while longer term galvanostatic measurements suggest that the design can completely eliminate cathode flooding using less than 2% of fuel cell power, and lead to stable operation with higher net power performance than a control design without EO-pump. This demonstrates that active EO-pump water management, which has previously only been demonstrated in forced-convection fuel cell systems, can also be applied effectively to miniaturized (<5 W) air-breathing fuel cell systems.