Influence of operating conditions on performance of small direct methanol fuel cell

A miniature membrane-electrode assembly (MEA) with 4 cm2 active area was fabricated by the catalyst coated membrane method.With this MEA,a single direct methanol fuel cell (DMFC) was prepared. The best operating conditions of this DMFC were investigated in detail. The results show that the cell performance is steady after being activated for 24 h in 70 ℃ hot water and depends on temperature and methanol concentration to a great extent. For example, the best methanol concentration is 1.5 mol/L at 23 ℃ and 1.0 mol/L at 60 ℃. At 80 ℃, better cell performance can be obtained with 0.2 mol/L methanol for low current density, but with 0.5 mol/L methanol for high current density. At 60 ℃, the best flow rate is 1.0 mL/min and 250 mL/min for methanol and oxygen, respectively.