Fig. 6

Current density (a) and power density (b) of the vapor-fed FC versus voltage, for a range of gas flow rates at 1.7 mmHg ethanol. Three runs were done for the 1000 mL/min ethanol data, and the standard deviation of the data is shown for the error bars. As the flow rate increased, the peak power increased, as expected. The peak power point also shifted to lower voltages. Maximum power density of 2 mW/cm² was obtained for 1000 mL/min, at 280 mV. Lines are polynomial fits to guide the eye