(490d) Water Management in a Seven-Layer Model of Proton Exchange Membrane Fuel Cell

The most critical problems to overcome in the proton exchange membrane (PEM) fuel cell technology are the water management. In former years, Springer and colleagues have presented a five-layer model that neglected the anode and cathode catalyst layer. On the other hand, Chen and Chang have presented another the five-layer model that was ignored the input anode and cathode channel. In this model, a steady-state, one-dimensional, isothermal and isobar model in a single PEM fuel cell is presented with a 117 Nafion membrane. A seven-layer theoretical model is proposed which includes anode and cathode inlet channels, anode and cathode gas diffusion layers (GDLs), catalyst layers (CLs), and the layer of proton exchange membrane. Also, the transport phenomena are considered by changing several crucial system parameters such as the relative humidity of reactant gas, stoichiometric ratio of reactant gases, the porosity of GDL, and the membrane thickness. The results show that with sufficient levels of humid reactant gases, the water management would improve for larger porosities of GDLs or a thinner membrane, and the resistance and overvoltage of the membrane can be reduced significantly as well. Furthermore, it is found that if the relative humidity is reduced to about 80%, membrane can be kept in the suitable moisture and flooding of water can be controlled. In addition, using the relative humidity 60% and 80%, stoichiometry coefficients 6 and 4, respectively for the cathode and anode, the cell performance will be optimized and water management is controllable. This model will help to select the amount of humidity, stoichiometric ratio, porosity of gas diffusion layer and membrane thickness so that the fuel cell would not suffer from dehydration and flooding.