Air-breathing membraneless laminar flow-based fuel cell with flow-through anode

Abstract

This paper describes a detailed characterization of laminar flow-based fuel cell (LFFC) with air-breathing cathode for performance (fuel utilization and power density). The effect of flow-over and flow-through anode architectures, as well as operating conditions such as different fuel flow rates and concentrations on the performance of LFFCs was investigated. Formic acid with concentrations of 0.5 M and 1 M in a 0.5 M sulfuric acid solution as supporting electrolyte were exploited with varying flow rates of 20, 50, 100 and 200 嬯min. Because of the improved mass transport to catalytic active sites, the flow-through anode showed improved maximum power density and fuel utilization per single pass compared to flow-over planar anode. Running on 200 嬯min of 1 M formic acid, maximum power densities of 26.5 mW/cm2 and 19.4 mW/cm2 were obtained for the cells with flow-through and flow-over anodes, respectively. In addition, chronoamperometry experiment at flow rate of 100 嬯min with fuel concentrations of 0.5 M and 1 M revealed average current densities of 34.2 mA/cm2 and 52.3 mA/cm2 with average fuel utilization of 16.3% and 21.4% respectively for flow-through design. The flow-over design had the corresponding values of 25.1 mA/cm2 and 35.5 mA/cm2 with fuel utilization of 11.1% and 15.7% for the same fuel concentrations and flow rate.