Robust and efficient charge storage by uniform grafting of TEMPO radical polymer around multi-walled carbon nanotubes

Abstract

The radical polymer of redox-active nitroxide was first terminally modified and then grafted onto multi-walled carbon nanotubes (MWNTs) by a facile terminating reaction. The radical polymer-grafted MWNTs allowed a high dispersibility in organic solvents and fadeless redox ability of nitroxide. The TEM images revealed that the radical polymer was successfully wrapped around a MWNT with nanometre thickness showing a core–shell nanotube structure homogeneously over the whole MWNTs. The radical polymer wrapping around the MWNT exhibited quantitative and high-rate redox properties of nitroxide suitable for a cathode-active material, which was prominent when compared with a radical polymer-grafted MWNT via a “grafting from” method. These results demonstrate that nano-scale homogeneous wrapping prevented the aggregation of the radical polymer and allowed the rapid counterion accommodation leading to quantitative and rapid charge propagation.