Layer-by-Layer Self-Assembled TEMPO-Oxidized Cellulose Nanofiber/Reduced Graphene Oxide/Polypyrrole Films for Self-Supporting Flexible Supercapacitor Electrodes

Abstract

In this study, self-supporting flexible supercapacitor electrodes were prepared by wrapping polypyrrole (PPy) on the surface of the TEMPO-oxidized cellulose nanofiber (TOCN)/reduced graphene oxide (RGO) film using a layer-by-layer selfassembly method under an oil−water separation environment. The obtained film had a three-dimensional-layered structure and exhibited a certain porosity, which is favored for the electrochemical performance. The areal capacitance of the TOCN/RGO/PPy film electrode was as high as 915 mF cm −2 , and 96.6% capacitance was retained after 2000 cycles of charge and discharge. Also, it maintained a higher rate retention of 98.4% after undergoing bending 200 times. These capacitance values are significantly better than RGO or PPy single-component films or their mixture with similar constituents. Furthermore, a solid-state symmetric supercapacitor was assembled by combining the TOCN/RGO/PPy electrode and CNF hydrogel films as a separator, which displayed an excellent specific capacitance of 195.8 F g −1 and a volumetric capacitance of 9.8 F cm −3 at the current density of 0.1 mA cm −2 . Meanwhile, an outstanding energy density of 13.04 Wh kg −1 with a power density of 200.6 W kg −1 was also obtained. These facts fully suggest that the TOCN/RGO/PPy film with a three-dimensional-layered structure in this study is promising for highperformance flexible energy-storage electrodes.

Recyclable Fe3O4/MWCNT/CNF composite nanopaper as an advanced negative electrode for flexible asymmetric supercapacitors

“…When the current density increases to 20 A g −1 , the energy density and power density are 18.8 W h kg −1 and 42.2 kW kg −1 , respectively. A comparison with previous studies on cellulose-based flexible supercapacitors 62–72 reveal that the present work yields competitive results, as seen from the Ragone plot (Fig. 5j).…”

Recent research progress of paper-based supercapacitors based on cellulose

“…For example, the introduction of the third component with excellent energy storage performance. On the basis of the former research, Qiang et al [66]prepared CNF/RGO/polypyrrole (PPy) paper electrode materials with sandwich structure by vacuum filtration. Figure 3C shows the preparation process of the composite.…”

‘Rigid‐soft’ synergistic effects to improve the microstructure and superflexibility properties of aramid nanofiber aerogel

“…Combining stiff and soft components to form hierarchical structures with elastic reticular structures and multipurpose functions are highly desired. Cellulose nanofibers (CNF) have been proved to provide abundant reaction sites and strong binding effects in synergy with other materials to synthesize highly robust assemblies, which is the result of various topologies and toughening mechanisms 8,9 . CNF as the dispersant, can prevent the self‐agglomeration of Aramid nanofiber (ANF).…”

“…Cellulose nanofibers (CNF) have been proved to provide abundant reaction sites and strong binding effects in synergy with other materials to synthesize highly robust assemblies, which is the result of various topologies and toughening mechanisms. 8,9 CNF as the dispersant, can prevent the self-agglomeration of Aramid nanofiber (ANF). Meanwhile, we consider using poly (vinyl alcohol) (PVA) as a reinforcement and disperse to enhance the superelastic properties of aerogels.…”