A study of hydrogen peroxide microfluidic fuel cells

This study investigated various effects, including reactant concentrations, volumetric flow rates and microchannel width, as well as the electrode distance, on the performance of microfluidic fuel cells employing hydrogen peroxide dissolved in alkaline and acid electrolytes as both fuel and oxidant, respectively. Three concentrations ranging from 0.1 M to 0.6 M and five volumetric flow rates ranging from 0.01 mL/min to 1.0 mL/min were tested in the present study for cell performance measurement and discussion. Three microfluidic fuel cells were tested here. Two of them have rectangular microchannel of 0.5 mm and 1.0 mm in width with electrode distance of 0.4 mm. An additional 0.5-mm-wide microchannel fuel cell was also tested with a shorter electrode distance of 0.2 mm. Results show that cell performed at either larger volumetric flow or with smaller microchannel width usually had higher current output at a given cell voltage. The highest cell output at 0.1 V and 0.1 M among the present cells was approximately 100 mA/cm2 produced by the cell whose microchannel width and electrode distance are 0.5 mm and 0.2 mm, respectively. However, with a higher reactant concentration of 0.6 M, the highest cell output at 0.1 V and 0.1 M among the present cells was 2.5 times higher than the abovementioned value, namely 250 mA/cm2, produced by the cell with microchannel width and electrode distance of 0.5 mm and 0.4 mm, respectively.