Cover Image, Volume 61, Issue 8

The cover image was created by Yuanchao Li and Trung Van Nguyen. The treatment of Nafion ionomer films with hot dry gas above their glass transition temperatures induces aggregation of the ionic groups and the formation of separate ionic-group-rich and ionic-group-sparse domains in the films. The latter creates hydrophobic interfaces and transport channels with lower water content and higher oxygen solubility. This novel approach improves water management and oxygen transport in the cathode catalyst layers of the PEM fuel cells which leads to higher electrochemical performance. Details are found in the article from Trung Van Nguyen and colleagues. (DOI: 10.1002/pol.20220774)