Treatment of Low C/N Ratio Wastewater by a Carbon Cloth Bipolar Plate Multicompartment Electroenhanced Bioreactor (CBM-EEB)

Catalyst layers are one of the most important parts of the PEM fuel cells and the cell performance is highly related to its structure. Catalyst layers are generally made by uniform distribution of catalyst on carbon cloth or carbon papers to form electrodes. In this paper, the idea of using non-uniform catalyst layer instead of common uniform catalyst layers is presented and simulated by a two-dimensional steady-state computational model. The model accounts for species transport, electrochemical kinetics, charge transport and current density distribution. A fuel cell test stand is designed and built to facilitate experimental validation of the model. Modeling results show that electrical current in catalyst layer is non-uniform, influenced by the channel-land patterns in bipolar plate geometry. Our simulations results also suggest that some non-uniform catalyst distribution patterns regarding to bipolar plate configuration will improve the performance of the whole catalyst layer by increasing catalyst utilization factor. Therefore, it is necessary to design non-uniform catalyst layers regarding to specific procedure. Plasma sputtering method is used to fabricate non-uniform catalyst layers. In this method, the platinum is deposited on the carbon cloth in the plasma-processing chamber. Indeed, an experimental procedure is presented to facilitate the fabrication of non-uniform catalyst layers by plasma sputtering.

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Influence factors and current response of carbon cloth bipolar plate electro-enhanced bioreactor (CBEEB) for nitrogen removal

10.1117/12.2619701 ◽

2021 ◽

Author(s):

Wu Kejia ◽

Zhu Hongguang ◽

Wang Bowen

Keyword(s):

Nitrogen Removal ◽

Influence Factors ◽

Bipolar Plate ◽

Carbon Cloth ◽

Current Response

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Graduated Flow Resistance Through a GDL in a Novel PEM Stack

ASME 2009 7th International Conference on Fuel Cell Science, Engineering and Technology ◽

10.1115/fuelcell2009-85075 ◽

2009 ◽

Author(s):

Terry B. Caston ◽

Kanthi L. Bhamidipati ◽

Haley Carney ◽

Tequila A. L. Harris

Keyword(s):

Fuel Cell ◽

Polymer Electrolyte Membrane ◽

Catalyst Layer ◽

Current Density Distribution ◽

Pem Fuel Cell ◽

Bipolar Plate ◽

Gas Diffusion ◽

Carbon Paper ◽

Carbon Cloth ◽

Electrolyte Membrane

The goal of this study is to design a gas diffusion layer (GDL) for a polymer electrolyte membrane (PEM) fuel cell with a graduated permeability, and therefore a graduated resistance to flow throughout the GDL. It has been shown that using conventional materials the GDL exhibits a higher resistance in the through-plane direction due to the orientation of the small carbon fibers that make up the carbon paper or carbon cloth. In this study, a GDL is designed for an unconventional PEM fuel cell stack, where the reactant gases are supplied through the side of the GDL rather than through flow field channels, which are machined into a bipolar plate. The effects of changing in-plane permeability, through-plane permeability, and thickness of the GDL on the expected current density distribution at the catalyst layer are studied. Three different thicknesses are investigated, and it is found that as GDL thickness increases, more uniform reactant distribution over the face of the GDL is obtained. Results also show that it is necessary to design a GDL with a much higher in-plane resistance than through-plane resistance for the unconventional PEM stack studied.

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Improvement of Electrical and Thermal Properties of Epoxy Based Graphite Bipolar Plate for PEMFC

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.26-28.853 ◽

2007 ◽

Vol 26-28 ◽

pp. 853-856 ◽

Cited By ~ 2

Author(s):

Hong Ki Lee ◽

Soo Heun Chae ◽

Joong Pyo Shim ◽

Sung Won Yang

Keyword(s):

Thermal Properties ◽

Polymer Electrolyte Membrane ◽

Expanded Graphite ◽

Graphite Powder ◽

Bipolar Plate ◽

Gas Diffusion ◽

Carbon Paper ◽

Mechanical And Thermal Properties ◽

Carbon Cloth ◽

Graphite Composite

The decrease of material cost for manufacturing fuel cell stack is strongly required for overcoming commercial restriction. The epoxy based graphite bipolar plate (BP) for polymer electrolyte membrane fuel cells (PEMFC) has been prepared and electrical, mechanical and thermal properties were compared. The density of graphite composite bipolar plate showed from 1.67 to 2.54 as graphite content is increased from 60 to 80w/o and decreased as expanded graphite was added. The contact resistance between epoxy/graphite bipolar plate and gas diffusion layer (GDL) had lower value using carbon cloth than carbon paper for GDL. The conformation of thermal stability, improvement of mechanical and electrical properties was accomplished by addition of expanded graphite powder.

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Testing and Evaluation of Aluminum Coated Bipolar Plates of PEM Fuel Cells Operating at 70° C

3rd International Conference on Fuel Cell Science, Engineering and Technology ◽

10.1115/fuelcell2005-74018 ◽

2005 ◽

Cited By ~ 1

Author(s):

Yue Hung ◽

Hazem Tawfik

Keyword(s):

Single Cells ◽

Bipolar Plate ◽

Pem Fuel Cells ◽

The Other ◽

Metal Corrosion ◽

Carbon Cloth ◽

Bipolar Plates ◽

Active Electrode ◽

Corrosion Resistant ◽

Aluminum Plates

Corrosion resistant metal treated bipolar plates with higher rigidity and electrical conductivity than graphite were developed and tested for PEM fuel cell applications. Six replicas of single cells were fabricated; two of graphite composites bipolar plates and the other four plates were coated aluminum. Two different high corrosion resistant coatings were used in this study and were applied to each pair of the metallic plates. An E-TEK Series 14-W MEA with carbon cloth GDL, thickness of Nafion <50 microns, <1mg/cm^2 total platinum content (anode & cathode) and 6.45 cm2 active electrode areas, was fitted to each cell and operated under identical conditions. The obtained data from the two graphite cells were averaged and plotted and the other aluminum cells’ data were similarly treated and plotted on the same graph for comparison. Generally, the metallic treated bipolar plate provided at least a 22% savings in hydrogen consumption in comparison to graphite. This is attributed to the lower bulk and surface contact resistance of the coated aluminum plates used in this study in relation to graphite. The results of the lifetime testing conducted at temperature of 70° C under loading condition ranging from 0 to 0.6 W that showed no indication of power degradation due to metal corrosion for at least 60 hours.

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