Industry Insights
Coating and Casting Techniques for Fuel Cell Development and Manufacture September 30, 2014 | by Robert Wildman, Business Development and Account Manager, Carestream Tollcoating, and Rick Daniels, General Manager, Carestream Tollcoating
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Carestream Contract Manufacturing enables efficient casting and coating of various portions of the device in proton exchange membrane fuel cells (PEMFC) and solid oxide fuel cells (SOFC). These main fuel cell components may be coated or cast simultaneously in the same manufacturing cycle to help lower the development and manufacturing costs. Key capabilities we offer include tight thickness control, precision casting, advanced quality systems and judicious use of materials.

Proton Exchange Membrane and Solid Oxide Fuel Cells

Despite their differing constructions and materials, proton exchange membrane and solid oxide fuel cells fundamentally behave in the same manner. As hydrogen is brought into the cell, it is split into ions and electrons at the electrode / electrolyte interface. Ions are able to pass through the electrolyte (membrane) but electrons cannot. The electrons flow between the electrodes via an external circuit that contains the object to be powered (the load). Once the electrons flow through the load, they react with the ions and oxygen on the other side of the membrane to form the exhaust.

Proton exchange fuel cells are powered by hydrogen gas (often produced in situ from reforming natural gas) and the exhaust is water and heat. PEM fuel cell electrodes often consist of carbon fiber papers coated with catalyzed carbon-based slurries. Platinum is the most common catalyst. A second component is the membrane separating anode and cathode, which can be cast separately and assembled later or cast directly on one of the electrodes.

To be successful, yields must be high as the materials of construction are expensive. Coatings must also be uniform and free of pinholes and other defects. Carestream delivers on these requirements by coating electrode materials on carbon fiber papers within the PEM fuel cell’s membrane electrode assembly (MEA), as illustrated in the image above. Carestream delivers superior thickness uniformity and also maximizes efficiency through optimized material handling (slurry and substrate) and process control.

Solid oxide fuel cells are driven by a diversity of hydrocarbons, including ethanol, methanol, diesel, biogas, natural gas, propane, liquefied petroleum gas, and jet fuel. The exhaust is water, heat, and CO2. There is significantly less CO2 than combustion for these fuel cells due to the efficiency of conversion.

Carestream works with fuel cell manufacturers to fabricate solid oxide fuel cell stacks based on multiple layers of coated ceramic structures. Casting presents an ideal solution because of its ability to produce thin, flat components, which are then stacked to create multiple layers.

Fuel cell customers can access our in-depth coating and manufacturing knowledge to bring their new products to market quickly and cost-effectively. Contact Robert Wildman for more information or to get started.

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