Abstract
This study examines the effect of cell temperatures and ethanol concentrations on the performance of a high temperature based direct-ethanol proton exchange membrane (PEM) fuel cell. A series of experiments were conducted at different combination of temperature (150 °C and 165 °C) and ethanol concentration (1 mol/L, 3 mol/L, 6 mol/L, and 9 mol/L) with an ethanol and air flow rate of 2 ml/min and 2 L/min, respectively. The resulting polarization and power curves show the overall effect of temperature and ethanol concentration on the cell performance. A two-factor analysis has been performed to investigate the main effect and interactions of temperature and concentration on maximum power and cell current at 0.2 V and 0.4 V. Result shows that the increase of cell temperature from 150 °C to 165 °C causes a significant improvement of cell potential and power output. At 165 °C, low concentration of ethanol (1mol/L) provides good power output until 150 mA/cm2, intermediate concentration (3 mol/L) gives high power output and allows for operation at high current density. It (3 mol/L) amplifies the effect of temperature at maximum power operation. Higher concentration causes the significant drop of cell performance. Therefore, the fuel cell operating condition of 3 mol/L and 165 °C provides balancing of ethanol and water molecules in the catalyst active side and gives the highest cell potential and power output.
