SEMINAR

DEPARTMENT OF CHEMICAL ENGINEERING 

Siyoung Choi 

Associate Professor, Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology 

Abstract

In this talk, we present how fluid/fluid interfaces can be engineered for two energy applications, polymer electrolyte membrane fuel cell (PEMFC) and redox flow battery (RFB). The first part of the talk includes a PEMFC catalytic layer that requires fast transport of reactants (proton and oxygen) and fast drainage of a product (water). To satisfy all the requirements, which is extremely difficult to achieve by conventional methods, we fabricate a macroporous PEMFC catalytic layer using a high internal phase Pickering emulsion template. Pt/C particles used as an emulsion stabilizer are exposed to the catalytic layer surface to maximize the reaction of proton and oxygen while interconnected macroporous network of ionomers supports the entire catalytic layer. The second part is about a membrane of the vanadium RFB system. It generally requires high proton conductivity and selectivity over vanadium ions. We use the conventional ionomer membranes (Nafion) that have high chemical/mechanical stability, but is expensive. By controlling their internal nanostructures using fluid/fluid interfaces, we could decrease permeability of vanadium ions by 1000 folds, thus reducing the membrane thickness as low as tens of nanometers while keeping the similar proton conductivity.