Gravure coating for roll-to-roll manufacturing of proton-exchange-membrane fuel cell catalyst layers

In this work, we demonstrate gravure coating as a highly relevant technology for the production of roll-to-roll coated catalyst layers. Our results showed gravure coating is capable of coating multi-meter lengths of platinum on carbon catalyst layers at industrially-relevant loadings. Multiple characterization methods were used to examine the microscale and macroscale morphology of the coated layer. Using full-web inspection it was shown that gravure coating produced uniform films in both the cross-web and down-web directions. Using electron microscopy, it was observed that gravure coating produced catalyst layers with larger pores than catalyst layers produced by ultrasonic spray coating. In situ performance testing of the gravure-coated electrodes showed promising results, though additional modifications to the catalyst layer ink and/or drying process are needed to match the catalytic activity of spray-coated catalyst layers. This study lays the foundation for future process science studies to understand the science of scale up.