Here we present the covalently grafting organic radical polymer, poly(2,2,6,6-tetramethylpiperidin-1-oxyl-4-yl methacrylate) (PTMA), onto the surface of multi-walled carbon nanotubes (MWNT) via free radical polymerization, affording MWNT-g-PTMA. The free-standing MWNT-g-PTMA-based electrode exhibits a high specific capacity of 262.9 mAh g⁻¹ and a >60% capacity retention (144 mAh g⁻¹) after 250 cycles, superior to that of physically mixed MWNT/PTMA electrode. Investigating the charge/discharge process by ex situ electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS), the excellent electrochemical performance of MWNT-g-PTMA-based electrode is attributed to the mutual participation of both p- and n-type redox reactions of PTMA with both cationic and anionic ions insertion/extraction into/from the electrode. Moreover, the capacity fading mainly results from irreversible side reactions during the n-type doping process of PTMA as investigating the charge/discharge process in two separate voltage ranges. This study may contribute to the understanding of energy storage mechanisms of radical polymers in the right way.

在这里，我们介绍通过自由基共价接枝有机自由基聚合物，聚（2,2,6,6-四甲基哌啶-1-氧基-4-甲基丙烯酸甲酯）（PTMA），到多壁碳纳米管（MWNT）的表面上聚合，得到MWNT- g- PTMA。独立的MWNT- g -PTMA基电极在250个循环后表现出262.9 mAh g ^-1的高比容量和大于60％的容量保持率（144 mAh g ^-1），优于物理混合的MWNT / PTMA电极。通过异位电子顺磁共振（EPR）和X射线光电子能谱（XPS）研究充电/放电过程，MWNT- g的出色电化学性能-基于PTMA的电极归因于PTMA的p-型和n-型氧化还原反应的相互参与，其中阳离子和阴离子离子插入/从电极中提取/提取。而且，容量衰减主要是由于在两个单独的电压范围内研究充电/放电过程而在PTMA的n型掺杂过程中发生了不可逆的副反应。这项研究可能有助于以正确的方式理解自由基聚合物的储能机理。