Elimination of Fuel Crossover in a Single-Flow Microfluidic Fuel Cell with a Selective Catalytic Cathode

Membraneless microfluidic fuel cells (MMFCs) remove the physical membrane in conventional fuel cells and are considered one of the promising micropower supplies for portable electronic devices. However, a co-laminar flow pattern should be maintained to avoid fuel crossover, which goes against the integration of the cell and its applicability. Herein, we adopt activated carbon (AC) as the cathode catalyst to trigger the oxygen reduction reaction (ORR) and construct a novel single-flow MMFC (SF-MMFC). Benefitting from the selective catalytic property, the unfavorable fuel-crossover issue is successfully avoided, and device construction is extremely simplified. One single reactant solution containing both fuel and electrolyte can successfully maintain SF-MMFC stable operation. The device delivers a volumetric power density of 218.6 mW cm–3; nevertheless, the ORR catalytic performance for AC powders is poorer than that of commercial Pt/C cathode. More importantly, the capital power production per unit cathode cost is 200 W $c–1. The utilization of catalyst with selective catalytic performance can accelerate the application potential of MMFC technology in powering portable electronic devices.