Evaluation of series resistance components of polymer electrolyte fuel cells using impedance measurement method

A fuel cell was characterized by using the impedance measurement method in order to evaluate the proton conduction resistivity () in the Nafion membrane and the contact resistivity (Q) between the MEA (membrane electrode assembly) surface and carbon block (separater).A non-woven sheet with a squred aperture area was inserted between the MEA surface and the carbon block.The electrical contact area between the MEA surface and the carbon block was varied by changing the aperture area of the non-woven sheet, while the gas supply area was fixed.The series resistance (Rs) of internal impedance of the fuel cell decreased with increasing the aperture area of the non-woven sheet.In this study, an equivalent circuit model of series resistance (Rs) was proposed to evaluate the proton conduction resistivity () and the contact resistivity (Q).As the result, their values were calculated to be = 8.1 cm and Q = 2.510 -2 cm 2 .