Fuel Cell Stacks Based on Micro Fuel Cell Units for a Substantially Increased Power Density

This paper introduces a bio-inspired fuel cell stack that has a substantially increased specific reactive surface area. The fuel cell stack is based on micro fuel-cell units that generally has a circular shape and an effective diameter on the order of 1 mm. A number of fuel cell units are arranged to form a fuel cell module, and then these modules are stacked one over another and electrically connected to form a fuel cell stack. An evaluation on the stack indicates that the specific reactive surface area may be increased by more than 10 fold compared to a conventional bipolar plate based fuel cell stack. A fuel cell stack that has such a substantially increased specific reactive surface area may enable a substantially increased power density, a substantially reduced fuel cell stack size, and an improved energy utilization efficiency. Additionally, the present fuel cell stack eliminates the fuel sealing problem in a planar fuel cell stack and allows a much higher operating pressure difference between the fuel and air streams.