Growth and use of Carbon Nanotube Nanoforests as Gas Diffusion Layers in Industrial-Scale Proton Exchange Membrane Fuel Cells.

Abstract

Proton exchange membrane fuel cells are promising sources of electrical energy for stationary generation, transportation, portable and backup power. The performance is greatly impacted by a variety of factors including cell temperature, gas flow rates, reactant humidification, and water management. Water management is especially challenging involving a fine balance between adequate humidification for conductivity and flooding due to excess water. Gas diffusion layers are a component within the fuel cell designed for the functions of permeability, electrical conductivity, mechanical strength, and water management. For this research, the production and use of carbon nanotube nanoforests for gas diffusion layers was investigated due to the carbon nanotubes’ inherent high electrical conductivity, permeability, and hydrophobicity. The nanoforest was used independently and paired with carbon paper and ceramic substrates. Although none of the developed diffusion layers performed better than the baseline, unexpected behaviors were observed and the path for future research is better defined.