The durability improvement for Proton Exchange Membrane Fuel Cell (PEMFC) must be based
on degradations mechanisms under full operation modes of fuel cell electric vehicle, because the life time of
PEMFC has not met the targets for fuel cell vehicle commercialization. This paper makes literature investigation
and analyzes for PEMFC performance degradation under main six kinds of operation modes of starting and
stopping, cold start, high potential, variable load, high current density and impurity pollution with summarizing
aging experimental and degradation mechanism under fuel cell vehicle modes. The main degradation
mechanisms include starting and stopping mode lead to cathode high potential and catalyst carbon support
eroded, proton exchange membrane attacked by enormous radical generated under idling mode, Pt catalyst
particles enlarged and washed away caused by variable load etc. Therefore, the important and urgent research
and development are to improve degradation prediction technique based on these degradation mechanisms
