Effect of Cathode Gasket Thickness to Performance of Direct Methanol Fuel Cells

This study considers the performance effect about a variation of the gasket thickness at the cathode side of the DMFC’s (Direct Methanol Fuel Cell) stack. Stack performance is largely influenced by the compressed thickness of GDL (Gas Diffusion Layer). The compressed thickness of GDL is directly controlled by gasket thickness. When GDL is not compressed enough, the ohmic loss is increased. Additionally, the differential pressure is decreased, because the channel of the separator is not blocked by GDL. On the contrary, being compressed extremely, GDL or MEA (Membrane Electrode Assembly) is physically damaged. The differential pressure is increased as well. In this respect, the optimization of the gasket thickness is one of the important factors to maximize the stack performance. In this study, the unit cell stacks with respect to changing gasket thickness at the cathode side are made in order to verify the effect about the compressed thickness of GDL. It is shown how the optimal gasket thickness may be achieved at the cathode side.