In order to meet the demand of gree

In order to meet the demand of greenhouse gas emission reduction, we should vigorously develop renewable energy technologies. Consequently, the proton exchange membrane fuel cell (PEMFC), which has the advantages of environmentally friendly ,high efficiency, high power density, safety and reliability, is selected as the fourth generation of energy conversion power generation. The only reaction product of PEMFC is pure water ,product water will be generated by the oxygen reduction reaction in the cathode side. Some of it take away by the reactant flow and the other part will be transferred to the anode side through the reverse diffusion. But, as the reaction proceeds, excessive product water will lead to serious flooding on the cathode side. When water fills the pores of the gas diffusion layer , the transport path of oxygen from the channel to the catalyst layer will be blocked. For PEM fuel cells, the factors that affect the electrochemical reaction efficiency of the fuel cells depend largely on the water content of the membrane and the gas diffusion layer is one of the components of membrane electrode. So water management of gas diffusion layer belongs to water management system. The purpose of PEMFC water management is to maintain the optimal water content in the membrane electrode. both to ensure the water content of the electrolyte membrane and remove the excess liquid water accumulates in the diffusion layer in time. Therefore, to maintain the performance and durability of the cell, proper water managements are urgently demanded. the GDL is an important component for water management, especially for water removal. What is the crux of the matter about PEMFC is to address the "bottleneck" issue of the water content variation in order to maintain the performance and durability of the cell. Also, it have endeavored to investigate liquid water transport processes and content of liquid water at various layers.