Multicomponent, multiphase interactions in fuel cell inks

Abstract Fuel cell catalyst layers (CLs) are porous electrodes that are fabricated from CL inks: colloidal dispersions of catalyst particles and ion-conducting polymer (ionomer), dispersed in solvent(s). The complex interactions between the ink components ultimately dictate CL microstructure and electrochemical performance. To control the CL formation process and optimize fuel cell performance, knowledge of these ink interactions is vital. In this review, we analyzed data from ink-focused papers to elucidate how ink parameters (solvent type, ionomer-to-carbon ratio, etc.) impact ink interactions and CL performance. We then discuss these results in the context of the current understanding of two critical ink interactions: ionomer/solvent and ionomer/catalyst particle interactions.