Fabrication and testing of a miniature H2/O2 and MeOH/O2 fuel cell

The construction and performance of a small-scale fuel cell using traditional catalysts and membrane separators is discussed. Cell active area was 1 cm × 1 cm, with a total unit cell volume of 0.3 cm3 each. Under well-hydrated conditions running under hydrogen and oxygen, these cells demonstrated over 600 mW cm−2 at 80 °C. Design of flow fields and the requirements for water management showed that flow channels that were too small may have resulted in early channel blockage on the cathode, leading to lower power. Miniature cells suffered from higher than expected interfacial resistance which increased with time and this may be due either to more difficult hydration control in the membrane at smaller dimensions, or less compression in the smaller scale size leading to higher flow field/diffusion layer interfacial resistances. Running single cells in methanol to alleviate hydration issues still showed much higher interfacial resistances, but cell performance was roughly 75 mW cm−2 at 80 °C in 1 M MeOH with 20 sccm of ambient pressure air, and 140 mW cm−2 in 1 M MeOH with 20 sccm ambient pressure O2. Lower performance in MeOH may be attributed to swelling of the sealing gaskets in methanol, leading to increased interfacial resistances over time.