Optimization of direct methanol fuel cell's membrane electrolyte assembly

Fuel cell is electrochemical device that convert the chemical energy of a fuel directly into electrical energy. A typically Direct Methanol Fuel Cell (DMFC) consists of basically anode side, solid polymeric electrolyte membrane and cathode side. Pt-Ru/C and Pt/C are electro catalysts used at anode and cathode sides respectively. While aqueous methanol solution is fed to the anode side, air as oxidizing agent is fed to the cathode side. DMFC is getting attention due to it simplicity, environmentally friendly working conditions and easy storage of aqueous methanol solution. However, power densities obtained from DMFC are lower than those obtained from Polymer Electrolyte Membrane Fuel Cell (PEMFC) due to relatively slow methanol oxidation reaction taking place at anode and methanol passage from anode side through solid polymer electrolyte to cathode side which is poisoning Pt being in the cathode side. The structural constituent such as type of support material, amount of electro catalyst loaded and type of polymer electrolyte membrane of Membrane Electrode Assembly (MEA) accepting as heart of fuel cell are also other parameters affecting the performance of DMFC. Therefore, researches related to the preparations and productions of MEAs are still continuing to obtain higher power densities form DMFC. In this M Sc. thesis, various MEAs prepared to obtain higher power densities were tested in the standard DMFC. By using potential versus current data obtained from each MEA test, power density to be produced from each tested MEA was determined. The structural constituents of MEA were optimized by using Taguchi experiment design method to obtaining maximum power densities.