Investigation of water droplet kinetics and optimization of channel geometry for PEM fuel cell cathodes

The kinetics and transport mechanisms of water droplets in model flow field channels of a low temperature polymer electrolyte fuel cell were investigated. The pressure drop at different air flows was measured for different channel geometries in a graphite plate as employed for fuel cell bipolar plates. The minimum air flow required for the movement of a water droplet in the flow channel was identified. From the experimental findings, recommendations for the development of flow fields with high condensate removal capabilities combined with low pressure differences were drawn to allow for an efficient operation of PEM fuel cells.