Novel Deposition of Pt∕C Nanocatalysts and Nafion® Solution on Carbon-Based Electrodes via Electrophoretic Process for PEM Fuel Cells

2006 ◽  
Vol 4 (1) ◽  
pp. 72-78 ◽  
Author(s):  
R. F. Louh ◽  
Hansen Huang ◽  
Felix Tsai
Keyword(s):  
Fuel Cells ◽  
Microstructural Analysis ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Pt Catalyst ◽  
Catalyst Loading ◽  
Power Performance ◽  
Effective Manner ◽  
Platinum Particles ◽  
Carbon Based

Nanosized platinum particles supported on carbon black carriers (Pt∕C) are popular for use in fabrication of proton exchange membrane fuel cells (PEMFCs). Here, an electrophoretic deposition (EPD) process is proposed to investigate the power performance of Pt∕C nanopowders onto various carbon-based electrodes for the PEMFC applications in a better controlled and cost-effective manner. Novel deposition of Pt∕C nanocatalysts and Nafion® solution via electrophoretic process give rise to higher deposition efficiency and a uniform distribution of catalyst and Nafion ionomer on the electrodes of PEMFCs. Preparation of an EPD suspension with good dispersivity is much desirable for an agreeable overall performance of catalyst coating in terms of types of organic solvents, milling processes, and use of pH adjusting agents and surfactants in the EPD suspension. The EPD suspension was prepared by sonication of mixture of Pt∕C nanopowders, Nafion solution and isopropyl alcohol, the optimal pH value of which was reached by using acetic acid or ammonium hydroxide. The colloidal stability of EPD suspension was achieved at pH ∼10 for an EPD suspension of either Pt∕C catalysts or mixture of Pt∕C catalysts and Nafion ionomer. A nicely distributed deposition of Pt∕C nanocatalysts and Nafion ionomer on both hydrophilic or hydrophobic carbon-based electrodes was successfully obtained by using Pt∕C concentration of 1.0g∕l, electrical field of 300V∕cm, and deposition time of 5min. Microstructural analysis results indicate that Pt∕C nanopowders not only embrace the entire surface of carbon fibers but also infiltrate into the gaps and voids in fiber bundles such that a higher contact area of the same loading of Pt∕C nanocatalysts through the EPD process is thus expected. At present, the EPD process can effectively save more of Pt catalyst loading on electrodes in PEMFC, as compared to conventional methods, such as screen printing, brushing, or spraying through the similar level of power performance for PEMFCs.

scholarly journals Investigation of Power Performance of a PEM Fuel Cell Using MATLAB Simulation

2020 ◽  
Vol 5 (1) ◽  
pp. 83-94
Author(s):  
Sarowar Jahan ◽  
Md. Tarikul Islam ◽  
Suman Chowdhury
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Catalyst Layer ◽  
Cell Voltage ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Limiting Current ◽  
Ohmic Loss ◽  
Power Performance

Fuel cell based power generation systems have gained remarkable interest in this modern age, due to its high conversion efficiency and reliability. Among the different types of fuel cells, PEM fuel cells are achieving more significance due to its fast start up time and low operating temperature. This paper studies the mathematical model of proton exchange membrane of fuel cell (PEMFC) using Matlab/SIMULINK software. The paper consists of the calculation of cell voltage, stack current, ohmic loss, activation loss. This model is used to research the fuel cell behavior and the characteristic of output values at different parameters. The model consists of the cathode gas channel, gas diffuser, catalyst layer, and the membrane. In order to composite shape of the gas diffuser and for its gradient in liquid water content, the gas diffuser is modeled as a series of parallel layers with different porosity. It represents in terms of the physical and thermodynamic parameters of the fuel cell. The curve of polarization is expressed parametrically as a function of the surface over potential. This paper expresses for cathode internal as well as overall effectiveness factors, active fraction of the catalyst layer resistance, catalyst layer, limiting current density, and the slope of the polarization curve.

Influence of Pt Catalyst Nanoparticle Size on the Electrochemical Performance of PEM Fuel Cells

2019 ◽  
Vol 41 (1) ◽  
pp. 933-936 ◽  
Author(s):  
Daniel J. Groom ◽  
Shreyas Rajasekhara ◽  
Stephanie Matyas ◽  
Zhiwei Yang ◽  
Mallika Gummalla ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Electrochemical Performance ◽  
Pem Fuel Cells ◽  
Nanoparticle Size ◽  
Pt Catalyst ◽  
Catalyst Nanoparticle

Synergien zwischen Batterie- und Brennstoffzellen/Synergies between battery and fuel cells - Evaluation based on structural and machine parameters in production processes

2020 ◽  
Vol 110 (10) ◽  
pp. 735-741
Author(s):  
Jens Schäfer ◽  
Hannes Wilhelm Weinmann ◽  
Dominik Mayer ◽  
Tobias Storz ◽  
Janna Hofmann ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Manufacturing Industries ◽  
Sich Eine ◽  
Future Technology ◽  
The Past ◽  
Production Processes ◽  
Exchange Membrane

Nach Ankündigung diverser batterieelektrischer Modelle wird auch die PEM (Proton Exchange Membrane)-Brennstoffzelle als mögliche Zukunftstechnologie im Last- und Linienverkehr diskutiert. Ob und wann sich eine Technologie durchsetzt, hängt von der verwendeten Produktionstechnik ab, denn diese bestimmt Stückzahlen und resultierende Kosten. Die Vergangenheit zeigt, dass sich produzierende Industrien oft entlang vorhandener Kompetenzen in etablierten Bereichen entwickelt haben. In diesem Beitrag sollen daher Synergiepotenziale zwischen der Batterie- und Brennstoffzellenfertigung diskutiert werden.   Following the announcement of various battery electric models, PEM fuel cells are also discussed as a future technology in truck and line traffic. Whether and when a technology will be generally accepted depends largely on the production technology used, as this determines the number of units and the resulting costs. The past has shown that manufacturing industries have often developed along existing competencies in established areas. This article will therefore discuss the potential synergies between battery and fuel cell production.

Fabrication and Performance Evaluation of Miniaturized Proton Exchange Membrane (PEM) Fuel Cells

2003 ◽  
Author(s):  
Tao Zhang ◽  
Pei-Wen Li ◽  
Qing-Ming Wang ◽  
Laura Schaefer ◽  
Minking K. Chyu
Keyword(s):  
Mass Transfer ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Free Convection ◽  
Current Density ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Cathode Side ◽  
Ohmic Loss ◽  
Fuel Cell Performance

Two types of miniaturized PEM fuel cells are designed and characterized in comparison with a compact commercial fuel cell device in this paper. One has Nafion® membrane electrolyte sandwiched by two brass bipolar plates with micromachined meander-like gas channels. The cross-sectional area of the gas flow channel is approximately 250 by 250 (μm). The other uses the same Nafion® membrane and anode structure, but in stead of the brass plate, a thin stainless steel plate with perforated round holes is used at cathode side. The new cathode structure is expected to allow oxygen (air) being supplied by free-convection mass transfer. The characteristic curves of the fuel cell devices are measured. The activation loss and ohmic loss of the fuel cells have been estimated using empirical equations. Critical issues such as flow arrangement, water removing and air feeding modes concerning the fuel cell performance are investigated in this research. The experimental results demonstrate that the miniaturized fuel cell with free air convection mode is a simple and reliable way for fuel cell operation that could be employed in potential applications although the maximum achievable current density is less favorable due to limited mass transfer of oxygen (air). The relation between the fuel cell dimensions and the maximum achievable current density is also discussed with respect to free-convection mode of air feeding.

Nonlinear Analysis of Two-Phase Instabilities in PEMFC Parallel-Channel Cathodes

2010 ◽  
Author(s):  
Nicholas Siefert ◽  
Chi-Hsin Ho ◽  
Shawn Litster
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Liquid Water ◽  
Proton Exchange Membrane ◽  
Critical Issue ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Stoichiometric Ratio ◽  
Two Phase ◽  
Voltage Loss

Liquid water management is a critical issue in the development of proton exchange membrane (PEM) fuel cells. Liquid water produced electrochemically can accumulate and flood the microchannels in the cathodes of PEM fuel cells. Since the liquid coverage of the cathode can fluctuate in time for two-phase flow, the rate of oxygen transport to the cathode catalyst layer can also fluctuate in time, and this can cause the fuel cell power output to fluctuate. This paper will report experimental data on the voltage loss and the voltage fluctuations of a PEM fuel cell due to flooding as a function of the number of parallel microchannels and the air flow rate stoichiometric ratio. The data was analyzed to identify general scaling relationships between voltage loss and fluctuations and the number of channels in parallel and the air stoichiometric ratio. The voltage loss was found to scale proportionally to the square root of the number of channels divided by the air stoichiometric ratio. The amplitude of the fluctuations was found to be linearly proportional to the number of microchannels and inversely proportional to the air stoichiometric ratio squared. The data was further analyzed by plotting power spectrums and by evaluating the non-linear statistics of the voltage time-series.

Separate Measurement of Current Density Under the Channel and the Shoulder in PEM Fuel Cells

2007 ◽  
Author(s):  
Lin Wang ◽  
Hongtan Liu
Keyword(s):  
Fuel Cells ◽  
Diffusion Layer ◽  
Current Density ◽  
Electrical Resistance ◽  
High Current Density ◽  
Gas Diffusion Layer ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Experimental Results

In a proton exchange membrane (PEM) fuel cell current density under the shoulder can be very different from that under the gas channel and the knowledge of where the current density is higher is critical in flow field designs in order to optimize cell performance. Yet, up to date this issue has not been resolved. In this study, a novel yet simple approach was adopted to directly measure the current densities under the channel and the shoulder in PEM fuel cells separately. In this approach, the cathode catalyst layer was so designed that either the area under the shoulder or the area under the channel was loaded with catalyst. Such a design guaranteed the currents generated under the shoulder and the channel could be measured separately. Experimental results showed that the current density produced under the channel was lower than that under the shoulder except in the high current density region. To determine whether the lateral electrical resistance of the gas diffusion layer (GDL) was the causes for lower current density under the channel, an additional set of experiments were conducted. In this set of experiments, a silver mesh was added on the top of the gas diffusion layer (GDL) and the experimental results showed that GDL lateral electrical resistance was not the cause and it had a negligible effect on lateral current density distribution.

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