The issue of transport phenomena is omnipresent in various electrochemical energy-conversion technologies. There is a need to understand and optimize the various means for products and reactants, whether gas, liquid, or ions to get to and away from the reaction sites. Such transport often results in concentration polarization and ohmic effects in various electrochemical cells. Mathematical modeling and advanced diagnostics are ideally suited to elucidate and explore the impacts of transport phenomena on device performance.

In this talk, we will discuss current research questions and issues related to transport phenomena in various electrochemical energy-conversion technologies including solar fuel generators, polymer-electrolyte fuel cells, and redox flow batteries. These various technologies share very similar architectures of typically ion-conducting polymer membranes sandwiched between thin catalyst layers that are porous electrodes. Specific topics to be discussed include reactant gas transport to the local reaction site in vapor-fed solar-fuel generators, local oxygen transport in polymer-electrolyte fuel cells, and ion transport and selectivity in redox flow batteries.

Acknowledgement

This work was funded by the Department of Energy under contract number DE-AC02-05CH11231.