화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.162, No.9, F1000-F1010, 2015
Internal Humidification in PEM Fuel Cells Using Wick Based Water Transport
The feasibility of a wick-based technique for direct humidification of the membranes in proton exchange membrane fuel cells (PEMFC) under dry feed operation is investigated. The fuel cell is operated in several configurations using a wicking material over the active area facilitating water transport directly to the membrane electrode assembly (MEA) through capillary action. Among different configurations (A - D) tested, wick used for configuration-B in co-flow mode and configuration-C in counter-flow mode showed improved performance with dry gas feed in comparison to control configuration-A which was operated using conventional bubble humidification. It is further shown that at low air stoichiometry of 1.5 with wick, enhanced peak power density of 475 mW/cm(2) was obtained without any external water supply to the wick in configuration-C under co-flow mode. The performance obtained due to the incorporation of wick in the conventional fuel cell system has been analyzed by means of electrochemical impedance measurements and estimating the Ohmic and charge transfer resistances in different configurations. It is shown that among different configurations, the Ohmic and charge transfer resistances corroborate the variation in fuel cell performance obtained from polarization curves. (C) 2015 The Electrochemical Society. All rights reserved.