Channel Dimension Constraints for Miniature Low Humidity PEM Fuel Cells

Numerous applications exist requiring power for small loads (<5W) with minimal mass operating in extreme ambient conditions. Making progress toward reducing stack mass, we investigate the influence of flow field channel depth and endplate compression on cell performance. The best performance was found at endplate compressions of 139 psi, cathode channel depths of 0.032 in and anode channel depths of 0.032 in. The maximum power mass-density achieved with these 4.84 cm² cells was 16.8 mW/g in a single cell stack. If deployed in a multicell stack, this same performance would translate to a power mass-density of 45.3 mW/g, nearing the performance of off-the-shelf lithium ion batteries (approximately 70 mW/g).