Poly(2,2,6,6‐tetramethylpiperidin‐1‐oxyl‐4‐yl methacrylate) (PTMA) is a typical organic battery material containing nitrogen and oxygen radicals. The grafting of PTMA onto graphene oxide to obtain composite cathode material poly(2,2,6,6‐tetramethylpiperidin‐1‐oxyl‐4‐yl methacrylate)‐Graphene Oxide (PTMA‐GO) via click chemistry is reported. The method of preparing PTMA‐GO is completed at room temperature, which can retain the oxygen‐containing functional groups on the surface of graphene oxide, and the process is simple and easy to conduct. The composite materials are characterized by infrared, X‐ray diffraction, thermogravimetry, and electron paramagnetic resonance. The cathode material is assembled in a button battery to measure its cyclic voltammogram, electrochemical impedance spectroscopy, and charge and discharge capacity cycles. It is found that the PTMA‐GO electrode is twice as conductive as the PTMA electrode alone. The specific capacity of the PTMA‐GO electrode is nearly 2.3 times higher than that of the PTMA electrode after 300 charge–discharge cycles. This represents an important reference value for the development of organic batteries, especially for the research of nitroxide radical polymer electrode materials.

A novel nitroxyl radical polymer poly(TEMPO-acrylamide-co-sodium styrene sulfonate) (abbreviated as poly(TAm-co-SSS)) was synthesized using 4-acrylamido-2,2,6,6tetramethylpiperidine (AATP) copolymerized with styrene sulfonate sodium (SSS). AATP was synthesized through a substitution reaction of acryloyl chloride. Meanwhile, poly(4-acrylamido-2,2,6,6-tetramethylpiperidine-1-nitroxyl radical) (PTAm) was prepared as a control sample. Then, the structures of products were characterized by nuclear magnetic resonance spectroscopy ( 1 H-NMR), Fourier transform infrared spectroscopy (FT-IR), high performance liquid chromatography-mass spectrometry (HPLC-MS), differential scanning calorimetry (DSC), X-Ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR), respectively. Additionally, the electrochemical impedance spectra (EIS) and the charge-discharge cycling properties were studied. The results demonstrated that the poly(TAm-co-SSS) with the side group of sodium sulfonate adjacent to TEMPO group exhibits a better charge-discharge cycling stability than that of the PTAm. Moreover, the charge specific capacity of the poly(TAm-co-SSS) is larger than that of the PTAm. Besides, the first coulombic efficiency of poly(TAm-co-SSS) is higher in comparison with that of PTAm. These superior electrochemical performances were ascribed to the synergistic effect of sulfonate ions group and nitroxyl radical structure, which benefits the improvement of charge carrier transportation of the nitroxyl radical polymers. Consequently, the nitroxyl radical poly(TAm-co-SSS) is promising for use in organic radical battery materials, based on the good electrochemical properties. such as nitroxide, phenoxyl, and galvinoxyl radicals. Due to the fact that radical polymers are completely amorphous and lack π-conjugation, charge transport occurs locally and through a reversible oxidation-reduction (redox) reaction mechanism, the radical polymers are expected to become a new generation of electrode materials [11,12].As a typical radical polymer, poly(4-acrylamido-2,2,6,6-tetramethylpiperidine-1-nitroxyl radical) (PTAm) indicates that it can be used as a novel, metal-free cathode material or long-period rechargeable devices [13,14]. Moreover, the stable amphoteric nitroxide block copolymers which were synthesized by block copolymerization were promising to be used as the EPR probes for bioimaging in vivo [15]. The electrochemical properties of the PTAm have been studied to confirm its potential for application in new electrode materials [16,17]. However, although good cyclability was usually reported [18][19][20], the TEMPO-substituted polyacrylamide was generally soluble in the electrolyte, leading to loss of capacity over time [21]. Crosslinking of the polymer was then a suitable option to improve the charge-discharge cycling stability [22]. In order to improve electrical properties of organic electronic polymers as electrode materials, ion-bearing repeat units were intentionally added to the macromolecular architecture of PTMA...