Syntheses and Electrochemical Properties of TEMPO Radical Substituted Silicones: Active Material for Organic Radical Batteries

A silicone‐based radical polymer 2 was synthesized by hydrosilylation of PMHS with 4‐allyl‐2,2,6,6‐tetramethylpiperidine‐ N ‐oxyl ether 1 in the presence of a platinum‐ or rhodium‐catalyst. A reversible redox peak of 2 at 3.56 V (vs. Li/Li + ) was observed by CV measurements. A coin‐shaped cell of 2 shows a discharge capacity of 46 mAh · g −1 , which is 47% of the theoretical capacity of 2 (98 mAh · g −1 ). A directly TEMPO‐substituted silicone, poly[methyl(2,2,6,6‐tetramethylpiperidine‐ N ‐oxyl‐4‐oxyl)siloxane] 3 was also obtained by rhodium‐catalyzed dehydrogenative alcoholysis of PMHS with TEMPO‐OH. The coin‐shaped cell of 3 shows a discharge capacity of 80 mAh · g −1 , which is 69% of the theoretical capacity of 3 (116 mAh · g −1 ). magnified image