Design and characterization of nonwoven fabrics for gas diffusion layer in polymer electrolyte membrane fuel cell

Abstract

Nonwoven materials for polymer electrolyte membrane fuel cells (PEMFC) were developed and evaluated. A PEMFC was built to study the membrane electrode assembly’s (MEA) behavior during operation. New gas diffusion layer (GDL) structures were manufactured and characterized. The strength and resistance values of the new materials are comparable to those of the commercial materials tested. It was found that there is no correlation between GDL’s initial thickness and its resistance. To optimize the water uptake in MEA, carbon fibers were impregnated with NaOH, which increased the resistance by 50%. Carbon/cellulose blended carbon paper has higher strength and resistance values than pure carbon fiber paper. For polyvinyl alcohol (PVA) coated carbon papers, drying temperature has a significant effect on resistance and strength. As the cellulose ratio decreases (PVA fiber amount increases), the resistance and strength of the carbon paper also decreases.

Keywords:

• fuel cell
• gas diffusion layer
• wet‐laying
• carbon paper
• conductivity
• strength

Acknowledgements

This study was supported by the US Department of Commerce through the National Textile Center (NTC), Grant No. 02‐07400, and through the Novel and Advanced Polymeric Materials Program, Grant No. G00003860, which is appreciated. The authors would like to thank Dr Gopal Krishnagopalan, Steve Howard and Henry Cobb for their help with the experimental system and Dr Bruce Tatarchuk and Dr Peter Schwartz for their suggestions.