Invited: Corrugated Cell Structures in Membrane Electrode Assemblies

The traditional Proton Exchange membrane fuel cell stack with its bipolar plates with grooved flow channels,
flat membrane electrode assemblies (MEAs), seals and end-plates has been the dominant
method of construction of multi kW fuel cells for the past 40 years. Smaller sub-watt and
portable applications have explored novel cell design variations such as “jelly roll”
concepts but none have been able to achieve the power density of the traditional
stacked plate design. The primary reason for this is the efficient collection of the current
and the compact packing of the MEAs. 

However at the present time one of the most challenging aspects of traditional PEM fuel
cell stacks is the difficulty to achieve the platinum catalyst utilization target of 0.2 g
Pt/kWe set forth by DOE. Good catalyst utilization can be achieved with state-of-theart
catalyst coated membranes (CCM) when ultra-low catalyst loadings (< 0.1 mg/cm2)
are used at lower current. Unfortunately when ultra-low loadings are used, the peak
power density is lower as compared to conventional loadings. Thus a larger total
active area and a larger bipolar plate is needed which results in a lower overall stack
power density and as such the DOE targets of power density can not be achieved
simultaneously
We thus now introduce in this proposal, our novel concept to increase the available MEA
active area by 2x or more while maintaining the same bipolar plate size. This is
achieved via a corrugated MEA sandwiched between bipolar plates. This is much like
corrugated cardboard, where the center corrugation (or flute) is the MEA. The
corrugations then form the gas channels thus there is no need for forming flow field
channels in the bipolar plates.  Thus the gas diffusion media as well as the membrane needs to be formed in the corrugated structure.  We will describe the state of our development on this approach.