Redox-Active Nitroxide Radical Polymers: From Green Catalysts to Energy Storage Devices

摘要

Robust but redox-active radical polymers bearing 2,2,6,6-tetramethylpiperidin-N-oxy (TEMPO) were investigated as a metal-free, green mediator/catalyst for the oxidation of alcohol derivatives, and as a new electrode-active and charge-storage material. The TEMPO-mediated oxidation of the primary alcohol group of the natural celluloseimproved the water-dispersivity of cellulose, and the polymer-supported catalysts or redox resins allow facile removal ofcatalysts from products by simple filtration. Other radical molecule (e.g. galvinoxyl) was also used as a mediator, whichis coupled with the molecular oxygen. A reversible one-electron redox reaction of TEMPO allowed its application as anelectrode-active material featuring high cyclability (> 500 cycles), relatively high battery electrode capacity (100-135mAh/g), and fast electrode kinetics, leading to the high power rate capability of the battery. The radical polymer-basedelectrodes also provided good processability and shape flexibility, which promised the paper-like and wearable energy-storage devices.