Lego-inspired membrane/catalyst layer interface for high mechanical robustness of polymer electrolyte membrane fuel cells

An interlocking interface resembling a Lego block can realize a durable and cost-effective polymer electrolyte fuel cell.

Article  |  Fall 2015

The use of hydrocarbon ionomers in polymer electrolyte fuel cells (PEMFCs) as a membrane to replace the commonly-used perfluorosulfonic acid ionomers has been widely explored in efforts to lower costs, raise fuel efficiency, and facilitate the manufacturing of membrane/electrode assemblies. However, for the practical use of hydrocarbon membranes for PEMFCs, attaining a tight interface between the HC membranes and the perfluorinated ionomer based catalyst layer to address the problem of interfacial delamination and consequent poor cell performance has proved challenging.

A new solution for enhancing interfacial adhesion between the hydrocarbon membrane and a perfluorinated catalyst layer in polymer electrolyte fuel cells was successfully demonstrated by Profs. Hee-Tak Kim and Jung-Ki Park. This solution was realized by the intrusion of micrometer-sized pillars fabricated on the HC membrane into the perfluorinated catalyst layer, forming an interlocking interface, like Lego blocks. Owing to a higher expansion with hydration for the hydrocarbon membrane than for the perfluorinated catalyst layer, a strong normal force occurs at the interface of the pillars and the holes, resulting in an eight-fold increase in the interfacial bonding strength and four-fold increase in durability under dynamic operation. Thus, the interlocking interface enhances applicability of a number of cost-effective HC membranes for fuel cell electric vehicles.

The present work was published in Advanced Materials (2015, 27, pp2974) and was selected as a back cover article.