Effect of Cathode Gasket Thickness to Performance of Direct Methanol Fuel Cells

2008 ◽  
Author(s):  
Hoon Choi ◽  
Yong-Sheen Hwang ◽  
Dae-Young Lee ◽  
Seo Young Kim ◽  
Suk-Won Cha
Keyword(s):  
Direct Methanol Fuel Cells ◽  
Membrane Electrode Assembly ◽  
Gas Diffusion ◽  
Differential Pressure ◽  
Cathode Side ◽  
Membrane Electrode ◽  
Ohmic Loss ◽  
Performance Effect ◽  
Direct Methanol ◽  
Made In

This study considers the performance effect about a variation of the gasket thickness at the cathode side of the DMFC’s (Direct Methanol Fuel Cell) stack. Stack performance is largely influenced by the compressed thickness of GDL (Gas Diffusion Layer). The compressed thickness of GDL is directly controlled by gasket thickness. When GDL is not compressed enough, the ohmic loss is increased. Additionally, the differential pressure is decreased, because the channel of the separator is not blocked by GDL. On the contrary, being compressed extremely, GDL or MEA (Membrane Electrode Assembly) is physically damaged. The differential pressure is increased as well. In this respect, the optimization of the gasket thickness is one of the important factors to maximize the stack performance. In this study, the unit cell stacks with respect to changing gasket thickness at the cathode side are made in order to verify the effect about the compressed thickness of GDL. It is shown how the optimal gasket thickness may be achieved at the cathode side.

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.

scholarly journals Surface Roughening of Electrolyte Membrane for Pt- and Ru-Sputtered Passive Direct Methanol Fuel Cells

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3969 ◽  
Author(s):  
Jeong ◽  
Cho ◽  
Cha ◽  
Park
Keyword(s):  
Fuel Cells ◽  
Direct Methanol Fuel Cells ◽  
Membrane Electrode Assembly ◽  
Gas Diffusion ◽  
Membrane Electrode ◽  
High Concentration ◽  
Ru Catalyst ◽  
Electrolyte Membrane ◽  
Direct Methanol ◽  
Methanol Fuel Cells

Platinum (Pt) and ruthenium (Ru) were sputtered on an electrolyte membrane and it was used as a membrane-electrode assembly for passive direct methanol fuel cells (DMFCs) operating with high concentration methanol solution (4 M). Thick (Pt of 300 nm and Ru of 150 nm) and thin (Pt of 150 nm and Ru of 75 nm) sputtered catalysts were prepared and their performance was first evaluated to find out the best sputtering conditions showing higher performance. Subsequently, four electrolyte membranes with different surface roughness were prepared to investigate its influence on the performance. As a result, the performance of the passive DMFC showed increasing tendency as the roughness is low, while the performance was decreased as the roughness was high, indicating there exists an optimal roughness of the electrolyte membrane. It was further investigated through morphological study through electron microscopy that such performance variation is attributed to the surface of sputtered Pt–Ru catalyst on the rough electrolyte membrane that adequate roughness induces the increase of reactive area while a too rough surface bears the poor contact of it with gas-diffusion layer.

Micro-Fluidic Assisted Passive Direct Methanol Fuel Cells

2012 ◽  
Author(s):  
Gladys Garza ◽  
Peiwen Li ◽  
Douglas Loy
Keyword(s):  
Fuel Cells ◽  
Direct Methanol Fuel Cells ◽  
Electrochemical Reaction ◽  
Cathode Side ◽  
Carbon Paper ◽  
Membrane Electrode ◽  
Operation Temperature ◽  
Direct Methanol ◽  
Methanol Fuel Cells ◽  
And Control

A novel design of micro-fluidic structure has been proposed to facilitate passive methanol supply and ventilation of carbon dioxide in direct methanol fuel cells (DMFC). Experimental study was conducted for three in-house fabricated cells which have different membrane-electrode-assemblies (MEA) and cathode-side air-breathing current collectors. Low rate of passive methanol supply and control was accomplished through capillary-force-driven mass transfer in the in-plane of carbon paper wicks. The low methanol supply rate using this passive method only meets the need of fuel of the electrochemical reaction, and there is almost no surplus methanol that could cross over the membrane. The micro-fluidic structure on the anode plate also makes passive removal of the CO2 gas from the electrochemical reaction. The influence of the concentration of methanol and cell operation temperature was examined and compared in the study. The results reveal very promising performance in the passive DMFCs when a methanol concentration is above 8M.

Study of the Variation of Catalyst Loading in Cathode for SPEEK/CSMM Membrane in Direct Methanol Fuel Cell (DMFC)

2014 ◽  
Vol 69 (9) ◽  
Author(s):  
S. E. Rosli ◽  
M. N. A. Mohd-Norddin ◽  
J. Jaafar ◽  
R. Sudirman
Keyword(s):  
Fuel Cell ◽  
Membrane Electrode Assembly ◽  
Cathode Side ◽  
Catalyst Loading ◽  
Methanol Permeability ◽  
Membrane Electrode ◽  
Anode Catalyst ◽  
Ether Ether Ketone ◽  
Poly Ether Ether Ketone ◽  
Direct Methanol

Variation of anode catalyst loading for modified sulfonated poly (ether ether ketone) (SPEEK) with charged surface modifying macromolecules (cSMM) membrane was studied, in order to get the higher performance in DMFC. The best optimal anode catalyst loading was 4 mgcm-2 for 30% Pt/Ru based on our previous result for this application.  The modified SPEEK/CSMM membrane was characterized to ensure of its better performance in term of water uptake and methanol permeability. In cathode side, the effect of 5% and 10% Pd/C  in 2,4 and 6 mgcm-2 of catalyst loading has been investigated with a fuel cell assembly. The preparation method of catalyst ink and membrane electrode assembly (MEA) was based on Dr. Blade method and hot pressing by using catalyzed diffusion media (CDM) method. The air flowrates were varied from 25-1000ml min-1, while 1M methanol concentrations, 1 ml min-1 of methanol flowrate and 60°C operating temperature were kept constant. These parameters were tested on the performance of single cell DMFC with 4 cm2 electrodes.The optimization catalyst loading will enhance the DMFC performance.  It was found, the best optimal cathode catalyst loading was 4 mgcm-2 for 10% Pd/C with  4 mgcm-2 for 30% Pt/Ru in anode side for this application. 

scholarly journals Cost-effective and durable Ru-sputtered Pt/C-based membrane–electrode assembly for passive direct methanol fuel cells

AIP Advances ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 095016 ◽  
Author(s):  
Wonyeop Jeong ◽  
Ikwhang Chang ◽  
Sangbong Ryu ◽  
Chunhua Zheng ◽  
Suk Won Cha ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Direct Methanol Fuel Cells ◽  
Cost Effective ◽  
Membrane Electrode Assembly ◽  
Membrane Electrode ◽  
Direct Methanol ◽  
Methanol Fuel Cells

Membrane electrode assembly for passive direct methanol fuel cells

2006 ◽  
Vol 162 (1) ◽  
pp. 497-501 ◽  
Author(s):  
HaeKyoung Kim ◽  
JungMin Oh ◽  
JoonHee Kim ◽  
Hyuk Chang
Keyword(s):  
Fuel Cells ◽  
Direct Methanol Fuel Cells ◽  
Membrane Electrode Assembly ◽  
Membrane Electrode ◽  
Direct Methanol ◽  
Methanol Fuel Cells

Parametric Investigations of Direct Methanol Fuel Cell Electrodes Manufactured by Spraying

2012 ◽  
Vol 9 (2) ◽  
Author(s):  
Babar M. Koraishy ◽  
Sam Solomon ◽  
Jeremy P. Meyers ◽  
Kristin L. Wood
Keyword(s):  
Electrochemical Performance ◽  
Direct Methanol Fuel Cells ◽  
Membrane Electrode Assembly ◽  
Membrane Electrode ◽  
Coating Process ◽  
Application Process ◽  
Fuel Cell Electrodes ◽  
Catalyst Layers ◽  
Direct Methanol ◽  
Continuous Fabrication

Key processing steps in the thin-film process of manufacturing catalyst layers for direct methanol fuel cells are catalyst ink formulation and its application. The catalyst ink is typically composed of supported or unsupported catalysts, binder (ionomer), solvents, and additives. Rheological properties of the ink, amount of binder, and choice of solvents are tuned to match the particular ink application process used to fabricate the electrode, as each coating process has its own unique requirements. Besides affecting the coating process, the choice and ratios of these components can significantly affect the electrochemical performance of the electrode. In this study, catalyst inks are designed and investigated for the spraying process, for utilization in the continuous fabrication of DMFC electrodes. For this purpose, the effect of the binder (ionomer) content on the performance of the electrodes is studied in detail. Decal-transfer electrodes are fabricated on a custom-built automated spraying apparatus with individually specified anode and cathode binder contents, and assembled to form a catalyst coated membrane (CCM) type membrane electrode assembly (MEA). These electrodes are rigorously tested to specifically identify their electrochemical performance, catalyst utilization and electrode morphology.

scholarly journals Modeling of the Transport Phenomena in Passive Direct Methanol Fuel Cells Using a Two-Phase Anisotropic Model

2014 ◽  
Vol 6 ◽  
pp. 812706 ◽  
Author(s):  
Zheng Miao ◽  
Jin-Liang Xu ◽  
Ya-Ling He
Keyword(s):  
Natural Convection ◽  
Outer Surface ◽  
Direct Methanol Fuel Cells ◽  
Transport Phenomena ◽  
Gas Diffusion ◽  
Methanol Concentration ◽  
Cell Performance ◽  
Membrane Electrode ◽  
Two Phase ◽  
Direct Methanol

The transport phenomena in a passive direct methanol fuel cell (DMFC) were numerically simulated by the proposed two-dimensional two-phase nonisothermal mass transport model. The anisotropic transport characteristic and deformation of the gas diffusion layer (GDL) were considered in this model. The natural convection boundary conditions were adopted for the transport of methanol, oxygen, and heat at the GDL outer surface. The effect of methanol concentration in the reservoir on cell performance was examined. The distribution of multiphysical fields in the membrane electrode assembly (MEA), especially in the catalyst layers (CLs), was obtained and analyzed. The results indicated that transport resistance for the methanol mainly existed in the MEA while that for oxygen and heat was primarily due to natural convection at the GDL outer surface. Because of the relatively high methanol concentration, the local reaction rate in CLs was mainly determined by the overpotential. Methanol concentration between 3 M and 4 M was recommended for passive liquid feed DMFC in order to achieve a balance between the cell performance and the methanol crossover.

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