Synthesis of Poly(TEMPO-Substituted Glycidyl Ether) by Utilizing t-BuOK/18-Crown-6 for an Organic Cathode-Active Material

Summary A nitroxide radical‐substituted polyether, poly(TEMPO‐substituted glycidyl ether) (PTGE), was synthesized using a potassium tert‐butoxide/18‐crown‐6 initiator. The presence of 18‐crown‐6 effected significant improvement in the reactivity of the chain end, thus allowing the polymerization to proceed at moderate temperatures to suppress the deactivation of the pendant nitroxide group. A high molecular‐weight polyether with a theoretical radical concentration was first obtained in high yield. Charging and discharging cyclability was much improved by cross‐linking, which helped the electrode‐active material stay on a current collector during the electrolysis. The polymer/vapor‐grown carbon nanofiber composite electrode exhibited a redox capacity comparable to the formula weight‐based theoretical density over 103 cycles and fast charging/discharging capability up to a rate of 60 C which corresponded to full charging and discharging in 60 s. The redox capacity was almost maintained for a composite layer with a remarkably high polymer ratio of 90 %, which demonstrated the presence of effective percolation network of the carbon nanofiber due likely to the affinity of the polyether to the carbon material.