Catalytic layer-membrane electrode assembly methods for optimum triple phase boundaries and fuel cell performances

Author(s):  
Imen Fouzaï ◽  
Solène Gentil ◽  
Victor Costa Bassetto ◽  
Wanderson Oliveira Silva ◽  
Raddaoui Maher ◽  
...  

A critical overview of MEA fabrication techniques is given focusing on the formation of triple phase boundaries, known for increasing PEMFC performances. Print-light-synthesis is a new emerging technology to achieve nanostructred MEA.

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 381
Author(s):  
Huichao Deng ◽  
Jiaxu Zhou ◽  
Yufeng Zhang

A membrane electrode assembly (MEA) with a novel trilaminar-catalytic layered structure was designed and fabricated for a micro-direct methanol fuel cell (μ-DMFC). The trilaminar-catalytic layer comprises three porous layers. The medial layer has a lower porosity than the inner and outer layers. The simulation results predicted a lower water content and a higher oxygen concentration in the trilaminar-catalytic layer. The novel trilaminar-catalytic layer enhanced the back diffusion of water from the cathode to the anode, which reduces methanol crossover and improves oxygen mass transportation. The electrochemical results of the half-cell test indicate that the novel MEA has a greatly increased cathode polarization and a slightly increased anode polarization. Thus, this novel μ-DMFC structure has a higher power density and a longer discharging time, and hence may be used in portable systems.


2013 ◽  
Vol 652-654 ◽  
pp. 819-822 ◽  
Author(s):  
Chun Guang Suo ◽  
Wen Bin Zhang ◽  
Hua Wang ◽  
Guang Min Wu

A direct methanol fuel cell (DMFC) with a novel double-layer structured membrane electrode assembly (MEA) was developed and a better performance was obtained. The double catalytic layer anode is composed of a hydrophilic inner catalyst layer with PtRu black and an outer catalyst layer with PtRu/C. In the double-layer structured anode, there existed a catalyst concentration gradient and porosity gradient, resulting in good mass transfer, proton and electron conducting. Furthermore, the delamination of the catalyst layer from the membrane was also resolved because of the inner hydrophilic catalyst film. To optimize the combination of the two catalysts layer a one-dimensional model based on Tafel type kinetics and semi-empirical mass transport coefficient was applied. The simulation of anode overpotential versus PtRu Blk inner layer thickness and PtRu/C outer layer thickness results showed a direct methanol fuel cell with a 5m thick inner PtRu black catalyst layer and an 8m thick outer 40wt%PtRu/C catalyst layer as anode electrode was the best.


2014 ◽  
Vol 17 (3) ◽  
pp. 95-103
Author(s):  
Diego F. Triviño-Bolaños ◽  
Gustavo A. López-Martínez ◽  
Rubén J. Camargo-Amado ◽  
William H. Lizcano-Valbuena

This paper presents preliminary results on the design, construction and evaluation of a passive mini direct ethanol fuel cell (DEFC), capillary fed with 2 mol l-1 aqueous ethanol, at a rate of 2.03 μL min-1, and air oxygen in the cathode through an air vent. Parameters such as pressure, temperature and time of manufacturing a membrane-electrode assembly (MEA) by hot-pressure were evaluated. As the electrode holder used a 0.25 cm2 carbon tissue which was deposited on the catalytic layer (C. L.) for both the anode (0.8 mg cm-2of PtRu/C) and the cathode (0.8 mg cm -2of Pt/C), Nafi on® 115 membranes were used as the electrolyte. The results show, an average power density of 302 μWcm2 under the best conditions used, a catalytic layer with a Nafi on percentage of 50% at 25 °C. A temperature of 125 °C, a pressure of 49.2 Kg/cm2, and 90 seconds duration were used to obtain the MEA.


2007 ◽  
Vol 26-28 ◽  
pp. 849-852
Author(s):  
Hong Ki Lee ◽  
Sung Wan Hong ◽  
Sung Won Yang ◽  
Woo Min Lee ◽  
Jeong Mo Yoon

For the regenerative fuel cell (RFC), water electrolysis cell performance using membrane electrode assembly (MEA) in polymer electrolyte fuel cell (PEMFC) were investigated. A part of Nafion had been secondary sprayed on the surface of catalytic layer and variation of cell performance was diminished. The conformation of stability, improvement of mechanical and electrical properties was accomplished by addition of PVDF, graphite and RuO2. With the addition of graphite power and RuO2, the voltage was decreased from 3.6V to 2.5V and 2.2V. The improvement of the mechanical properties was obtained by addition of PVDF. The electrolysis cell manufactured with MEA electrode was showed less decomposition voltage of 1.3V than with Nafion electrode at 10A of applied current. The stability of MEA was confirmed from 30 days of cell operation


Author(s):  
Jonghyun Hyun ◽  
Seok-Hwan Yang ◽  
Gisu Doo ◽  
Sungyu Choi ◽  
Dong-Hyun Lee ◽  
...  

The durability of the membrane electrode assembly (MEA) is one of the important requirements for the successful commercialization of anion exchange membrane fuel cells (AEMFCs). While chemical stabilities of the...


Author(s):  
C. C. Kuo ◽  
W. E. Lear ◽  
J. H. Fletcher ◽  
O. D. Crisalle

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.


2009 ◽  
Vol 30 (4) ◽  
pp. 329-336 ◽  
Author(s):  
Mia Kim ◽  
Moon Sik Hyun ◽  
Geoffrey M. Gadd ◽  
Gwang Tae Kim ◽  
Sang‐Joon Lee ◽  
...  

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