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Fuel Cell Development
Development of Metal Bipolar Plates for
Proton Exchange Membrane (PEM) Power System
The Center for Fuel Cell Development at the
Institute for Research and Technology Transfer (IRTT) of the Farmingdale
State University of New York has successfully developed new metal treated
bipolar plates for PEM fuel cell power stacks. These power stacks are much
safer, very robust and more economical than the graphite bipolar plates
that are currently being developed nationwide. The metal bipolar plates
provide at least a 12% saving in hydrogen consumption in comparison to
graphite because of the lower ohmic resistance of metal.
Two patents have been filed to protect IRTT’s
exciting PEM fuel cell technology that includes a new reactants flow field,
robust power stack designs, and innovative manufacturing techniques for
efficient metal bipolar plates. A cost effective Membrane Electrode
Assembly (MEA) and utilizing dry reactants is currently under development
at the IRTT.
Various prototypes with power ranging from 2 W to 8
kW have been fabricated, assembled and tested at the IRTT as shown in
Figure (1). The results of the lifetime testing conducted under variable
loading showed no indication of power degradation due to metal corrosion
for nearly 700 hours as depicted in Figure (2). This comparison of graphite
and metal bipolar plates clearly demonstrates the viability and superiority
of this novel technology.
Most bipolar plates are made of graphite composites
that are known to be relatively expensive, highly brittle, and have low
electric conductivity. Metal bipolar plates such as aluminum and zinc are
less expensive, more robust, highly conductive and very easy to machine or
die-cast. The lack of brittleness in metal bipolar plates permits the
exertion of the necessary tightening torque on the stack’s tie rods
to completely prevent reactant gas leakage to the outside or around the
Membrane Electrode Assembly (MEA) without any possibility of cracking,
unlike graphite.
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