Heat and Fluid Flow in Porous Media for Polymer-Electrolyte Fuel Cells

Global warming and greenhouse gas (GHG) emissions are two critical issues currently addressed by scientists all over the world. Some GHGs are emitted to the atmosphere through natural processes and human activities. Among the human activities, internal combustion engine vehicles are significant producers of harmful greenhouse emissions. In polymer-electrolyte fuel cells (PEFCs), the anode, electrolyte, and cathode are sandwiched together, known as a membrane electrode assembly. Both the anode and the cathode include a gas diffusion layer (GDL) and a catalyst layer (CL). Often a microporous layer is sandwiched between GDL and CL for better mass transport. To achieve higher output voltages and higher power, cells can be combined with a large fuel cell stack. The most important operating parameters for a PEFC operation are temperature and pressure. A PEFC can be operated at room temperature as high as 80°C, while the operating pressure can be at ambient pressure or at a higher pressure.