MEA comprising catalyst layer having thickness gradient, preparation method thereof, fuel cell comprising the MEA and operation method thereof

摘要

A membrane electrode assembly(MEA) for a fuel cell, a method for preparing the MEA, a fuel cell containing the MEA, and a method for operating the fuel cell are provided to prevent the problem due to the mounting of a humidifier by lowering the humidification level of a reactive material. A membrane electrode assembly for a fuel cell comprises a cathode catalyst layer which is coated so as to have a thickness gradient, and is operated under the no humidification condition or the low humidification condition having a humidity of 20% or less. Preferably the thickness of a catalyst layer at the side of an air or oxygen entrance is larger than that of a catalyst layer at the side of an air or oxygen exit.