Electrolyte Membrane Water Research Articles

Numerical investigation on the characteristics of water transfer in PEMFC with bionic flow channel

The content and the transmission characteristics of the water in the polymer electrolyte membrane fuel cell (PEMFC) have a significant influence on its performance. So far, there are few separate numerical studies on the process of water transport in the bionic flow channel, and the performance of bionic flow channel is different from conventional flow channel in part owing to the differences of their water drainage. Therefore, in order to understand the water drainage process of bionic flow channel, two different types of bionic flow channels are adopted in this paper. The method of numerical simulation is used to study the transmission process of liquid water in the bionic flow channel of different placement orientations. The simulation results found that the orientations of bionic flow channel has an influence on the process of water transport in the flow channel, and the process of water drainage also has a significant difference in the two different types of bionic flow channel.

Separation Analysis of Electro-Osmosis and Diffusion of Water in Electrolyte Membrane of PEMFC Under Low-Humidity Operation

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Separation Analysis of Electro-Osmosis and Diffusion of Water in Electrolyte Membrane of PEMFC under Low-Humidity Operation

To alleviate performance degradation of proton exchange membrane fuel cell (PEMFC) due to membrane dehydration during low-humidity operation, it is essential to understand and control water transports through electrolyte membrane. In this study, the water vapor and current distributions on the anode side of a PEMFC was firstly measured by using the effective visualization tool proposed in our previous work, and the net water transport coefficient was quantitatively estimated under low-humidity conditions. Furthermore, the electro-osmotic drag (EOD) coefficient of Nafion membrane was also measured based on hydrogen pumping method. Therefore, the electro-osmosis and back-diffusion of water through the electrolyte membrane in the operating PEMFC can be separately analyzed. Results revealed that the cathode inlet humidification promotes the back-diffusion of water rather than the electro-osmotic flow, and prevents the membrane dryout.