Etched Metal Fuel Cell Plates are Thinner, Stronger and Offer Superior Electrical Performance
The Proven Benefits of Etched Metal Fuel Cell Plates
Due to their robustness and improved volumetric power density when compared to graphite, extremely corrosion resistant Stainless Steel and Titanium bipolar flow field plates for PEM fuel cells offer many advantages:
- Where space is limited, they are thinner producing a shorter stack.
- Metals offer superior electrical and heat conductivity than non-metal solutions.
- For mobile applications, metal plates are less fragile and able to withstand mechanical impact.
- For long-life applications, stainless steel and titanium provide extended life times plus improved electrical performance.
Photo etched metal plates are ideal for applications requiring good volumetric power densities, long life and robust performance.
Photo etching metal offers fuel cell designers unique time-saving and cost advantages:
- No expensive tooling or time consuming mold making required.
- Rapid prototyping is automatic, plus only a new phototool is required for design changes.
- Thickness is typically .050” or less.
- Multiple channel levels can be etched onto the fuel cell plate.
- Concept to part in only 3 weeks.
- Smooth surfaces are burr and stress free.
- Prototype to high volume.
- Tooling typically costs just $400.
Conductive Coating for Fuel Cells
Robotic Spray Coating Process Applies Conductive Coating to Fuel Cells, Battery Grids and other Energy Storage Devices
Tech Etch has designed and developed a robotic spray coating process used to apply conductive coatings to fuel cells, battery current collectors, and other energy storage devices that require low resistance coatings. Conductive coatings enhance battery performance with improved electrical contact between active materials and the current collector, resulting in longer battery life and reliable cycle life. They also provide oxidation and corrosion protection which enables aggressive electrolytes and provides extended shelf life by reducing leakage and self-discharge.
The robotic nature of the spray coating equipment, with an articulated spray head that delivers coatings from all angles, provides very uniform delivery of the conductive coatings. The system ensures even and complete coverage of components with very tight coating thickness tolerances. The equipment is designed to deliver both epoxy and water based coatings.
PEM Fuel Cells with Bi-Polar Plates
Fuel cells generate power by converting the chemical energy of a fuel into electrical energy through an electrochemical reaction. Fuel cells use hydrogen as the fuel and oxygen as the oxidant in this reaction. The result is electricity with the by-products of water and heat.
The Proton Exchange Membrane (PEM) fuel cell contains an electrolyte that allows protons to be transmitted from one side to the other. PEM fuel cells operate at a much lower temperature than other fuel cells, around 90°C. A single cell is shown here to illustrate the operation of a fuel cell.
A fuel cell consists principally of two electrodes, the anode and the cathode, separated by a polymer electrolyte membrane. The electrodes are coated on one side with a catalyst. Hydrogen fuel is fed into the anode and air enters through the cathode. In the presence of the catalyst, the hydrogen molecule splits into two protons and two electrons. The electrons from the hydrogen molecule flow through an external circuit, creating the electrical current. Protons from the hydrogen molecule are transported through the electrolyte membrane, and combine at the cathode with the electrons and oxygen from the air to form water and generate heat.
When stacked in series, fuel cells generate useful voltages and power levels. They are attractive power generation devices because of their inherently high efficiency, zero or very low noxious emissions, low noise, and potential to be manufactured in virtually any size.
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