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

• Published in: Macromolecular chemistry and physics 2009-09, Vol.210 (17), p.1402-1407
• Main Authors: Suguro, Masahiro, Mori, Atsunori, Iwasa, Shigeyuki, Nakahara, Kentaro, Nakano, Kaichiro
• Format: Article
• Language: English
• Subjects: Batteries; Dehydrogenation; Discharge; Ethers; Hydrosilylation; lithium ion; organic radical; Radicals; rechargeable battery; silicone; Silicones; TEMPO
• ISSN: 1022-1352; 1521-3935
• DOI: 10.1002/macp.200900251

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). The transition‐metal‐catalyzed reactions of PMHS with TEMPO derivatives afford silicone‐based organic radical polymers with interesting charge/discharge capabilities, making them promising candidates as active materials in rechargeable batteries.