Effect of Channel Depth and Cell Temperature on the Performance of a Direct Methanol Fuel Cell

2013 ◽  
Vol 10 (3) ◽  
Author(s):  
Ebrahim Alizadeh ◽  
Mousa Farhadi ◽  
Kurosh Sedighi ◽  
Mohsen Shakeri
Keyword(s):  
Fuel Cell ◽  
Direct Methanol Fuel Cell ◽  
Membrane Electrode Assembly ◽  
Bipolar Plate ◽  
Cell Performance ◽  
Membrane Electrode ◽  
Channel Depth ◽  
Direct Methanol ◽  
Pt Black ◽  
Methanol Fuel Cell

The main goal of this study is to analyze the performance of the direct methanol single cell using three channel depths at various cell temperatures. The membrane electrode assembly (MEA) used Nafion® 117, by loading a Pt-Ru (4 mg/cm2) catalyst at the anode and Pt-black (4 mg/cm2) catalyst at the cathode. The active area of the MEA was 100 cm (Jung et al., 2009, “Investigation of Flow Bed Design in Direct Methanol Fuel Cell,” J. Solid State Electrochem., 13, pp. 1455–1465). In these sets of experiments, anode and cathode channel depth were varied simultaneously. The cell performance is improved with an increase of temperature in a certain range because the conductivity of the membrane and the reaction kinetics at both the anode and cathode are increased. Also, when the channel depth of the bipolar plate is decreased from 2.0 to 1.0 mm, the cell performance increases. The decreased channel depth leads to an increase in the linear velocity of reactants and products.

Critique and Improvement of a One-Dimensional Semianalytical Model of a Direct Methanol Fuel Cell

2012 ◽  
Vol 9 (5) ◽  
Author(s):  
C. C. Kuo ◽  
W. E. Lear ◽  
J. H. Fletcher ◽  
O. D. Crisalle
Keyword(s):  
Fuel Cell ◽  
Polarization Curve ◽  
Current Density ◽  
Direct Methanol Fuel Cell ◽  
Membrane Electrode Assembly ◽  
Membrane Electrode ◽  
One Dimensional ◽  
Implicit Equation ◽  
Direct Methanol ◽  
Methanol Fuel Cell

A constructive critique and a suite of proposed improvements for a recent one-dimensional semianalytical model of a direct methanol fuel cell are presented for the purpose of improving the predictive ability of the modeling approach. The model produces a polarization curve for a fuel cell system comprised of a single membrane-electrode assembly, based on a semianalytical one-dimensional solution of the steady-state methanol concentration profile across relevant layers of the membrane electrode assembly. The first improvement proposed is a more precise numerical solution method for an implicit equation that describes the overall current density, leading to better convergence properties. A second improvement is a new technique for identifying the maximum achievable current density, an important piece of information necessary to avoid divergence of the implicit-equation solver. Third, a modeling improvement is introduced through the adoption of a linear ion-conductivity model that enhances the ability to better match experimental polarization-curve data at high current densities. Fourth, a systematic method is advanced for extracting anodic and cathodic transfer-coefficient parameters from experimental data via a least-squares regression procedure, eliminating a potentially significant parameter estimation error. Finally, this study determines that the methanol concentration boundary condition imposed on the membrane side of the membrane-cathode interface plays a critical role in the model’s ability to predict the limiting current density. Furthermore, the study argues for the need to carry out additional experimental work to identify more meaningful boundary concentration values realized by the cell.

A Novel Structure of Membrane Electrode Assembly for DMFC

2009 ◽  
Vol 60-61 ◽  
pp. 339-342
Author(s):  
Chun Guang Suo ◽  
Xiao Wei Liu ◽  
Xi Lian Wang
Keyword(s):  
Fuel Cell ◽  
Direct Methanol Fuel Cell ◽  
Catalyst Layer ◽  
Membrane Electrode Assembly ◽  
Gas Diffusion ◽  
Cathode Side ◽  
Membrane Electrode ◽  
Anode Side ◽  
Direct Methanol ◽  
Methanol Fuel Cell

Membrane electrode assembly (MEA) is the key component of direct methanol fuel cell (DMFC), the structure and its preparation methods may bring great effects on the cell performances. Due to the requirement of the high performance of the MEA for the micro direct methanol fuel cell (DMFC), we provide a novel double-catalyst layer MEA using CCM-GDE (Catalyst Coated Membrane，CCM；Gas Diffusion Electrode，GDE) fabrication method. The double-catalyst layer is formed with an inner catalyst layer (in anode side: PtRu black as catalyst, in cathode side: Pt black as catalyst) and an outer catalyst layer (in anode side: PtRu/C as catalyst, in cathode side: Pt/C as catalyst). The fabrication procedures are important to the new structured MEA, thus three kinds of fabrication methods are studied, including CCM-GDE, GDE-Membrane and CCM-GDL methods. It was found that the CCM-GDE technology may enhance the contact properties between the catalyst and PEM, and increase the electrode reaction areas, resulted in increasing the performance of the DMFC.

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