SUBJECT: Ph.D. Dissertation Defense
   
BY: Laam Tse
   
TIME: Thursday, May 11, 2006, 10:00 a.m.
   
PLACE: MARC Building, 114
   
TITLE: Membrane Electrode Assembly (MEA) Design for Power Density Enhancement of Driect Methanol Fuel Cells (DMFCs)
   
COMMITTEE: David W. Rosen, Chair (ME)
Peter J. Hesketh (ME)
S. Mostafa Ghiaasiaan (ME)
Meilin Liu (MSE)
Tom F. Fuller (ChBE)
Comas L. Haynes (GTRI)
 

SUMMARY

Micro-direct methanol fuel cells (micro-DMFC) can be the power supply solution for the next generation of handheld devices. The applications of the micro-DMFCs require them to have high compactness, high performance, light weight, and long life. The major goal of this research project is to enhance the volumetric power density of direct methanol fuel cells (DMFCs) without significant volume increase. A performance roadmap has been formulated and showed that by patterning the planar membrane electrode assembly (MEA) to 2-D and 3-D corrugated manifolds can greatly increase the power generation with very modest overall volume increases. In this project, different manufacturing processes for patterning MEAs with corrugations have been investigated. A folding process was selected to form 2D triangular corrugations on MEAs for experimental validations of the performance prediction. The experimental results show that the volumetric power densities of the corrugated MEAs have improved by about 25% compared to the planar MEAs, which is lower than the expected performance enhancement. ABAQUS software was used to simulate the manufacturing process and identify the causes of deformations during manufacture. Experimental analysis methods like impedance analysis and 4 point-probes were used to quantify the electrochemical deformations and performance loss during the forming process. A model was proposed to relate the expected performance of corrugated MEAs to manufacturing process variables. Finally, different stacking configurations and issues related to cell stacking for corrugated MEAs are also investigated.