An air-breathing membraneless microfluidic fuel cell (MMFC) with a three-dimensional graphite felt anode is proposed and simulated. The graphite felt

used as anode catalyst layer as well as diffusion layer of fuel cell

provides more possibility to improve the performance of MMFCs owing to its large porosity. A single-phase

three-dimensional and isothermal steady flow model under acidic electrolyte condition is established for the proposed MMFC with comsol multiphysics. The characteristics of mass transfer and fuel crossover as well as the influence of flow rate of reactants and thickness of the graphite felt on the cell performance are discussed. The results show that comparing with the carbon paper and the carbon cloth flow-through anode

the maximum current density and the maximum power density of the MMFC with a graphite felt anode increased 12% and 50% at the flow rate of 333 μl·min-1

respectively. The ratio of parasitic current density caused by the fuel crossover to the output current density was 0.86% when the cell voltage is 0.8 V. The current density and power density increase with increasing thickness of graphite felt and reactant flow rate

and then trend to be steady.