Cationic Polymerization of Poly(vinyl ether) Bearing a TEMPO Radical: A New Cathode‐Active Material for Organic Radical Batteries

PTVE was synthesized as a new active material for organic radical batteries. Cationic polymerization of a monomer bearing a TEMPO radical moiety took place. The spin concentration of PTVE was estimated to be 2.75 × 10 21 spins · g −1 (100% spin per repeating unit). The PTVE is extremely stable; there is no decrease in spin concentration when storing PTVE samples for more than a year under aerobic conditions at room temperature. The redox potential of PTVE is 3.55 V (vs. Li/Li + ). A coin‐type cell using a PTVE/VGCF composite electrode was also fabricated, and then performed charge/discharge measurements. The discharge capacity of PTVE is 114 mAh · g −1 (84% of the theoretical value).