Carbon Nano-Tube Based Nano-Porous Layer in Membrane-Electrode Assemblies for Polymer Electrolyte Membrane Fuel Cells

摘要

In the membrane-electrode assemblies (MEAs) for polymer electrolyte membrane fuel cells (PEMFCs), there is a micro-porous layer (MPL) which is placed between gas-diffusion layer (GDL) and catalyst-coated layer (CCL). It roles as a buffer layer between GDL and CCL, where it helps removing the byproduct (Water) and connects electrically to conduct the generated electrons outside of the electrochemical reaction sites. However, commercial MPLs are normally composed of nano-particulated bulk carbon, which are hot-pressed in the manufacturing process. Therefore it is normally brittle and their thickness is micro-scale. This feature sometimes causes the structural breakdown by the byproduct or cracked by repeated pressurization of hydrogen or air. In addition, the micro-thick layer is not proper to remove the byproduct because such thick structure would rather disturb removing the byproduct water from the inside of the CCL.