Experimental Investigation of the Ordered Gas Diffusion Layer Performance in PEMFC Under Various Operating Conditions

The Proton Exchange Membrane Fuel Cell (PEMFC) is a highly efficient green electrochemical conversion device using hydrogen energy. The gas diffusion layer (GDL) is the thickest part of the membrane electrode in PEMFC. The microstructure of GDL takes an important role in the migrations of gas, liquid, heat, and electron. Optimizing the GDL microstructure is crucial to improve the gas–liquid two-phase flowing behavior and enhance the PEMFC performance. Therefore, a kind of GDL with the ordered pore structure is designed with the template method to provide large pores channel for water elimination and normal small pores channel for gas delivery. Then, a comparison between our ordered GDL and commercial GDL has been performed using a PEMFC test platform under different working conditions, including relative humidity and temperature. The results show that the ordered GDL can improve the PEMFC performance under high humidity compared with commercial GDL, which is mainly because the large pore channel in ordered GDL can enhance water transfer. The peak power density of the fuel cell with ordered GDL is increased by 10.8% compared with commercial GDL at the same high relative humidity. However, with a decrease in relative humidity, the ohmic loss gradually replaces the mass transfer optimization caused by the perforation, and the performance of the fuel cell with ordered GDL shows a downward trend. Compared with laser perforation, the current work proposed the template method to prepare the ordered GDL, which is low-cost and convenient and provides an alternative concept for batch preparation of ordered GDL.