A Numerical Study on the Performance of Air-breathing Microfluidic Fuel Cells

In this study, computational modeling and numerical simulation used to investigate the characteristics and the effects of both the electrode conditions and operating conditions on the performance of air-breathing direct formic acid microfluidic fuel cells by performing steady state and 3-D simulations of the microfluidic fuel cells. Firstly, a three-dimensional microfluidic fuel cell model was established using COMSOL Multiphysics 5.1 to simulate the fuel cell performance. Subsequently, both V-I curves obtained from simulation and published experimental data under similar operating condition were compared to assure the validity of the simulation. The transport phenomena in the microfluidic fuel cells were formulated with continuity equation, momentum equation, species transport equation, and charge equation. The porous media flow in the gas diffusion layer was described by Brinkman equation. The Butler-Volmer equations were applied to get the V-I curves. Besides, numerical simulation model can be used for further optimization, to analyze the current density distribution and the reactant concentration on both electrodes were also discussed.