Nafion is a brand name for a sulfonated tetrafluoroethylene based fluoropolymer-copolymer synthesized in 1962 by Dr. Donald J. Connolly at the DuPont Experimental Station in Wilmington Delaware U.S. patent 3,282,875. From Wikipedia
Kumamoto University reports lab results pointing to a non‑fluorinated route for low‑ to mid‑temperature cells with scale-up and durability testing pending.