Modeling of Liquid Water Transport in Cathode Catalyst Layer of PEM Fuel Cells

2009 ◽  
Author(s):  
Prodip K. Das ◽  
Xianguo Li ◽  
Zhong-Sheng Liu
Keyword(s):  
Water Transport ◽  
Liquid Water ◽  
Catalyst Layer ◽  
Pem Fuel Cells ◽  
Water Flooding ◽  
Dimensionless Time ◽  
Cathode Catalyst ◽  
Water Production ◽  
Cathode Catalyst Layer ◽  
Liquid Water Transport

The performance of a polymer electrolyte membrane (PEM) fuel cell is significantly affected by liquid water generated at the cathode catalyst layer (CCL). Conversely, the ionic conductivity of PEM is directly proportional to its water content; it must have sufficient water. Therefore, it is essential to maintain a delicate water balance, which seems difficult without properly understanding liquid water transport from the CCL. In the present study, a one-dimensional analytical solution of liquid water transport across the CCL is derived from the fundamental transport equations. The effect of CCL wettability on liquid water transport and the effect of liquid water “flooding” on reactant transport have been investigated. It has been observed that hydrophilic characteristic of a CCL plays significant role on the liquid water transport. The liquid water saturation in a hydrophilic CCL can be reduced by increasing the surface wettability or lowering contact angle. Based on a dimensionless time constants analysis, it has been shown that liquid water production from the phase change process is negligible compared to water production from the electrochemical process.

Effect of Vibration on the Liquid Water Transport of PEM Fuel Cells

2009 ◽  
Author(s):  
Luis Breziner ◽  
Peter Strahs ◽  
Parsaoran Hutapea
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Water Transport ◽  
Liquid Water ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Cell Performance ◽  
Sinusoidal Vibration ◽  
Fuel Cell Performance ◽  
Liquid Water Transport

The objective of this research is to analyze the effects of vibration on the performance of hydrogen PEM fuel cells. It has been reported that if the liquid water transport across the gas diffusion layer (GDL) changes, so does the overall cell performance. Since many fuel cells operate under a vibrating environment –as in the case of automotive applications, this may influence the liquid water concentration across the GDL at different current densities, affecting the overall fuel cell performance. The problem was developed in two main steps. First, the basis for an analytical model was established using current models for water transport in porous media. Then, a series of experiments were carried, monitoring the performance of the fuel cell for different parameters of oscillation. For sinusoidal vibration at 10, 20 and 50Hz (2 g of magnitude), a decrease in the fuel cell performance by 2.2%, 1.1% and 1.3% was recorded when compared to operation at no vibration respectively. For 5 g of magnitude, the fuel cell reported a drop of 5.8% at 50 Hz, whereas at 20 Hz the performance increased by 1.3%. Although more extensive experimentation is needed to identify a relationship between magnitude and frequency of vibration affecting the performance of the fuel cell as well as a throughout examination of the liquid water formation in the cathode, this study shows that sinusoidal vibration, overall, affects the performance of PEM fuel cells.

scholarly journals Analytical modeling framework for performance degradation of PEM fuel cells during startup–shutdown cycles

RSC Advances ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 2216-2226
Author(s):  
Yunqi Li ◽  
Xiran Chen ◽  
Yuwei Liu ◽  
Danping Xiong ◽  
Jing Li ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Analytical Modeling ◽  
Catalyst Layer ◽  
Pem Fuel Cells ◽  
Performance Degradation ◽  
Cathode Catalyst ◽  
Modeling Framework ◽  
Carbon Corrosion ◽  
Cathode Catalyst Layer

An analytical modeling framework coupling carbon corrosion and an agglomerate model is established to predict the performance degradation of the cathode catalyst layer (cCL) during startup–shutdown cycles.

A Low Order Control-Oriented Model of Liquid Water Transport in PEM Fuel Cell

2008 ◽  
Author(s):  
Angelo Esposito ◽  
Cesare Pianese ◽  
Yann G. Guezennec
Keyword(s):  
Fuel Cell ◽  
Water Transport ◽  
Diffusion Layer ◽  
Liquid Water ◽  
Gas Diffusion Layer ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Computational Time ◽  
Liquid Water Transport

In this work, an accurate and computationally fast model for liquid water transport within a proton exchange membrane fuel cell (PEMFC) electrode is developed by lumping the space-dependence of the relevant variables. Capillarity is considered as the main transport mechanism within the gas diffusion layer (GDL). The novelty of the model lies in the simulation of the water transport at the interface between gas diffusion layer and gas flow channel (GFC). This is achieved with a phenomenological description of the process that allows its simulation with relative simplicity. Moreover, a detailed two-dimensional visualization of such interface is achieved via geometric simulation of water droplets formation, growth, coalescence and detachment on the surface of the GDL. The accomplishment of reduced computational time and good accuracy makes the model suitable for control strategy implementation to ensure PEM fuel cells operation within optimal electrode water content. Furthermore, the model is useful for optimization analysis oriented to both PEMFC design and balance of plant.

In-Situ Observation of the Water Distribution in Porous Layers of PEMFCs by Soft X-Ray Radiography

2010 ◽  
Author(s):  
Takashi Sasabe ◽  
Shohji Tsushima ◽  
Shuichiro Hirai
Keyword(s):  
Water Transport ◽  
Temporal Resolution ◽  
Liquid Water ◽  
Water Distribution ◽  
Transport Phenomena ◽  
Catalyst Layer ◽  
In Situ Observation ◽  
X Ray ◽  
Porous Layers ◽  
Liquid Water Transport

To observe the liquid water distribution in porous layers of an operational Proton Exchange Membrane Fuel Cell (PEMFC) with high spatial and temporal resolution, Laboratory-based soft X-ray microscopy has developed. This system can generate low energy X-ray in the soft X-ray range, and maximum sensitivity towards water is achieved. A point X-ray source with a diameter of less than 1.0 μm and the improved detector optics contribute to realize a spatial resolution of 500 nm and a temporal resolution of 1.0 sec/frame. In addition, in-plane and through-plane observations of an operational PEMFC were carried out. In the in-plane observation test, non-uniform distribution of liquid water in the plane of the catalyst layer was observed, and the importance of appropriate design of the catalyst layer to liquid water transport phenomena was suggested. In the through-plane observation test, liquid water discharge behavior near under the rib area was observed, and the importance of channel wall wettability to liquid water transport phenomena was also suggested.

Liquid Water Transport in PEM Fuel Cells

2019 ◽  
Vol 12 (1) ◽  
pp. 67-79 ◽  
Author(s):  
Jay B. Benziger ◽  
Tamara Whitaker ◽  
Erin Kimball ◽  
Ioannis G. Kevrekidis
Keyword(s):  
Fuel Cells ◽  
Water Transport ◽  
Liquid Water ◽  
Pem Fuel Cells ◽  
Liquid Water Transport
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