Graphene‐Indanthrone Donor–π–Acceptor Heterojunctions for High‐Performance Flexible Supercapacitors

Abstract

To overcome the low energy density bottleneck of graphene‐based supercapacitors and to organically endow them with high‐power density, ultralong‐life cycles, etc., one rational strategy that couple graphene sheets with multielectron, redox‐reversible, and structurally‐stable organic compounds. Herein, a graphene‐indanthrone (IDT) donor–π–acceptor heterojunction is conceptualized for efficient and smooth 6H+/6e− transfers from pseudocapacitive IDT molecules to electrochemical double‐layer capacitive graphene scaffolds. To construct this, water‐processable graphene oxide (GO) is employed as a graphene precursor, and to in situ exfoliate IDT industrial dyestuff, followed by a hydrothermally‐induced reduction toward GO and self‐assembly between reduced GO (rGO) donors (D) and IDT acceptors (A), affording rGO‐π‐IDT D–A heterojunctions. Electrochemical tests indicate that rGO‐π‐IDT heterojunctions deliver a gravimetric capacitance of 535.5 F g−1 and an amplified volumetric capacitance of 685.4 F cm−3. The assembled flexible all‐solid‐state supercapacitor yields impressive volumetric energy densities of 31.3 and 25.1 W h L−1, respectively, at low and high power densities of 767 and 38 554 W L−1, while exhibiting an exceptional rate capability, cycling stability, and enduring mechanically‐challenging bending and distortions. The concept and methodology may open up opportunities for other two‐dimensional materials and other energy‐related devices.

Engineering Textile Electrode and Bacterial Cellulose Nanofiber Reinforced Hydrogel Electrolyte to Enable High‐Performance Flexible All‐Solid‐State Supercapacitors

“…[1][2][3][4][5] In this sense, all-solid-state supercapacitors (ASCs) composed of two flexible electrodes with hydrogel electrolyte in between have excellent attributes of fast charge/discharge, high power density, long cycle life, and high deformation. [6][7][8] However, several challenges still exist for ASCs, such as low stability/compatibility and large interfacial resistance between the flexible electrodes and hydrogel electrolyte, resulting in unavoidable relative displacement among the components and sluggish charge/ion transport kinetics during consecutive bending or stretching cycles. [9][10][11] Thus, there is considerable interest in device configuration designs that integrate highly compatible individual components to maximize the performance of the electrode materials.…”

Electrochemically Exfoliated Chlorine‐Doped Graphene for Flexible All‐Solid‐State Micro‐Supercapacitors with High Volumetric Energy Density

“…High-performance integratable micro-power-source is among the keys for Internet of Things devices, such as wireless sensors, remote controls, and wearable electronics, and thus have attracted ever increasing attention in the microelectronics field. [1][2][3][4][5][6][7][8] In recent years, some flexible high-performance in view of their few-atoms thicknesses, large specific surface areas, and good planar mass transport, and extraordinary mechanical and electron properties. [33] In particular, dopedgraphene as one typical type of 2D materials represents among the most appealing candidates for capacitive energy storage, owing to their rich chemical functionalities through tunable chemical/hydrogen bonds, van der Waals as well as the ample defects on both the basal planes.…”

Quinolinediol Molecule Electrode and MXene for Asymmetric Supercapacitors with Efficient Energy Storage

“…Among carbon-based materials, graphene has been studied widely due to its large surface area, high conductivity, and excellent chemical stability. , Organic molecules are fixed on the surface of graphene via chemical bonds or π–π interaction. Different to the chemical bonds, the π–π interaction attracts more attention because it scarcely damages the sp 2 hybrid system of graphene, which ensures electroconductivity. , Pan et al prepared graphene–indanthrone heterojunctions, which show a high capacitance (535.5 F g –1 ) and an outstanding rate capability (88% over 20.0 A g –1 ). Bandyopadhyay et al.…”