화학공학소재연구정보센터
Journal of Power Sources, Vol.196, No.4, 1940-1947, 2011
Effects of a microporous layer on the performance degradation of proton exchange membrane fuel cells through repetitive freezing
The gas diffusion layer (GDL) covered with a mtcroporous layer (MPL) is being widely used in proton exchange membrane fuel cells (PEMFCs) However the effect of MPL on water transport is not so clear as yet hence many studies are still being carried out In this study the effect of MPL on the performance degradation of PEMFCs is investigated in repetitive freezing conditions Two kinds of GDL differentiated by the existence of MPL are used in this experiment Damage on the catalyst layer due to freezing takes place earlier when GDL with MPL is used More water in the membrane and catalyst layer captured by MPL causes permanent damage on the catalyst layer faster More detailed information about the degradation is obtained by electrochemical impedance spectroscopy (EIS) From the point of view that MPL reduces the ohmic resistance it is effective until 40 freezing cycles but has no more effect thereafter On the other hand from the point of view that MPL enhances mass transport it delays the increase in the mass transport resistance (c) 2010 Elsevier B V All rights reserved