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SearchDr. Colleen Spiegel
Dr. Colleen Spiegel is a mathematical modeling and technical writing consultant (President of SEMSCIO) and Professor holding a Ph.D. and an MSc degree in Engineering. She has seventeen years of experience in engineering, statistics, data science, research & technical writing work for many companies as a consultant, employee, and independent business owner. She is the author of ‘Designing and Building Fuel Cells’ (McGraw-Hill, 2007) and ‘PEM Fuel Cell Modeling and Simulation Using MATLAB’ (Elsevier Science, 2008). She previously owned Clean Fuel Cell Energy, LLC, which was a fuel cell organization that served scientists, engineers, and professors world-wide.
If you work with fuel cells, then you are definitely working with polarization curves. The polarization curve does not have a lot of specificity; however, it is one of the most common methods of testing a fuel cell. It also allows an easy comparison to other published polarization curves. The polarization curve displays the voltage output of the fuel cell for a given current density loading...
Fuel cell system designs range from very simple to very complex depending upon the fuel cell application and the system efficiency desired. A fuel cell system can be very efficient with just the fuel cell stack and a few other balance-of-plant components or may require many outside components to optimize...
Different characterization techniques enable the quantitative comparison of every property and part of the fuel cell stack. By characterizing the fuel cell properly, you can understand why the fuel cell is performing well or poorly. These techniques help discriminate between activation, ohmic and concentration losses, fuel crossover, and...
Fuel cell operating conditions depend upon the cell and stack design. The operating parameters that affect fuel cell performance are: Operating Pressure, Operating Temperature, Flow Rates of Reactants, and Humidity of Reactants. Using the correct operating condition for each parameter is...
The design elements of a micro or MEMs fuel cell stack are the same as a larger fuel cell stack, except that there should be special considerations for...
The fuel cell electrode is a thin, catalyst layer where electrochemical reactions take place. The electrodes are usually made of a porous mixture of carbon-supported platinum and ionomer. To catalyze reactions, catalyst particles have contact to both protonic and electronic conductors. There also must be passages for...
The electrolyte layer is essential for a fuel cell to work properly. In low-temperature fuel cells, when the fuel in the fuel cell travels to the catalyst layer, the fuel molecule gets broken into protons (H+) and electrons. The electrons travel to the external circuit to power the load, and the hydrogen proton (ions) travel through the electrolyte until it reaches...
The gas diffusion layer is sandwiched between the catalyst layer and the bipolar plates as shown in Figure 1. The gas diffusion layer (GDL) provides electrical contact between electrodes and the bipolar plates and distribute reactants to the electrodes. The GDL also allows the water that is generated as a result of the chemical reaction to move between the electrodes and the ...
The fuel cell stack consists of many layers, including: The Membrane Electrode Assembly (MEA), Gaskets, Flow field plates, and End plates. There are two standard methods of assembling the membrane electrode assembly (MEA) in low-temperature fuel cells. The catalyst layer can be applied in one or two steps. For the first method, there are five common ways to prepare and apply the catalyst for the GDL/catalyst assembly:
Fuel cells have been known in the scientific community for about 150 years. They began to be explored in the 1800s, and have been extensively researched during the second half of the twentieth and early twenty-first century. A summary of fuel cell history is shown...
Hydrogen has many unusual characteristics compared with other elements. Some of these interesting and unusual characteristics include...Table 1 compares relevant properties of hydrogen, methane, methanol, ethanol, propane, and gasoline—all of which can be used as fuel for fuel cells.
Fuel cells are electrochemical devices that convert chemical energy from the reactants directly into electricity and heat. The device consists of an electrolyte layer in contact with a porous anode and cathode on either side. An illustration of a fuel cell with reactant/product gasses and the ion conduction flow directions through the cell is...