Fluoropolymer Comprising Pendent Groups with Ionic Bis(Sulfonyl)Imide Moiety and Perfluoroether Terminal Group

A fluoropolymer is described comprising pendent groups having the formula: —(CF)—(OCF)—(OCF)—SO—[NX—SO(CF)—SO]—NX—SO—Rf wherein Rf is a perfluoroether and Xand Xare independently cationic counterions. Also described are various articles including catalyst ink, polymer electrolyte membranes, and membrane electrode assemblies comprising the fluoropolymer described herein; as well as a method of making a fluoropolymer.