High Mass Specific Capacitance Research Articles

One-pot preparation of one-dimensional hierarchically porous carbon@SnO2 nanocomposites for flexible fabric-based supercapacitor electrodes

The design of functional energy storage materials with superior performances has become the focus topic with the growing energy crisis in recent years. Herein, porous carbon nanofibers@tin dioxide (PCNFs@SnO2) composites are prepared by one-pot electrospinning and followed by carbonization. The PCNFs@SnO2 possesses a hierarchically porous structure containing mesopores and micropores. The specific surface area is as high as ∼ 559.4 m2 g−1, and the total pore volume can reach 0.28 cm3 g−1. Meanwhile, the nonwoven fabric surface is coated with a silver layer through the screen printing technique to obtain silver-coated nonwoven fabric (SNF). Importantly, PCNFs@SnO2 and SNF are combined to obtain flexible fabric-based functional materials. As a primary energy application, the prepared PCNFs@SnO2/SNF electrode has a high mass specific capacitance of 583.1 F g−1 at 1 A g−1, a high area specific capacitance of 933 mF cm−2 at 1 mA cm−2, and a good rate capability (70 % at 10 A g−1). The supercapacitor device with two PCNFs@SnO2/SNF electrodes also shows outstanding cycling durability, capacitor retention is as high as ∼ 91.52 %, after 10000 charging/discharging cycles. In brief, our study may provide an innovative route for designing hierarchically porous one-dimensional carbon nanocomposites for supercapacitors with high performances.

Coal-based graphene formation by CO2 laser scribing: Various structures and excellent electrochemical performance

The laser-induced technique is a cost-effective and environmentally-friendly method for upgrading coal into high value-added graphene materials. Here, laser-induced graphenes (LIGs) were prepared from different rank coals in one-step under vacuum conditions using a designed CO2 infrared laser device. The characteristics of laser-induced products were studied by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. The electrochemical characteristics of coal-based laser-induced graphenes (C-LIGs) were examined in a three-electrode test system. Results show that subbituminous coal, bituminous coal, and low-metamorphic anthracite can form LIG with fewer layers after laser irradiation. The morphology of C-LIG is a layered porous structure. Corrugated folds can be observed at the edges of the C-LIG layer. There are only a few layers of graphene, with the majority of them concentrated in 2–10 layers. The most interesting result is that LIG prepared from low volatile bituminous coal has the highest crystallinity, the largest aromatic layer size, and the lowest average graphene layer number. Furthermore, LIG made from low volatile bituminous coal (LIG-ZJ) exhibits excellent electrical double-layer capacitive behavior, low equivalent series resistance (3.73 Ω), good rate capability, excellent cycling stability, greater Coulombic efficiency, and high mass specific capacitance. The LIG-ZJ electrode exhibits a high specific capacitance of 1879.92 F/g at 1 A/g, which is nearly ten times greater than that of most activated carbon electrodes reported. In addition, its power density and energy density can reach up to 924.07 kW/kg and 217.11 Wh/kg. These results indicate that coal-based laser-induced graphene has significant potential for application in the field of electrochemical energy storage.

Preparation and capacitance performance of NiCo layered double hydroxide by multi-step constant current electrodeposition method

In comparison with single-step electrodeposition, multi-step electrodeposition for electrode preparation is more effective in releasing internal stresses, utilizing the highly efficient deposition time at the beginning of the electrodeposition, improving deposition efficiency, and producing adhesive-free high-performance electrodes with controllable mass. In this paper, NiCo layered double hydroxide (NiCo-LDH) with similar mass was successfully deposited by a two-electrode constant-current electrodeposition method using nickel foam as the substrate through different electrodeposition steps. A comparative study was conducted on the effects of NiCo-LDH deposition steps on the morphology, total deposition time, and electrochemical performance of NiCo-LDH samples. The results show that the mass of NiCo-LDH grown on foam nickel is similar when the number of deposition steps is from 1 to 6 at 12–13 mg, the coating of foam nickel substrate became more uniform. The total deposition time has decreased from 2550 s for 1-step deposition to 1542 s for 6-step deposition, reducing the occupation time of the electrodeposition equipment. As the number of deposition layers increases, the specific capacitance of NiCo-LDH shows a trend of first increasing and then stabilizing. The high mass specific capacitance of NiCo-LDH electrode material deposited in 6 steps is 953 F g−1 at a current density of 3 mA cm−2. The assembled asymmetric supercapacitor device achieved an energy density of 0.309 mWh cm−2 at a power density of 4.25 mW cm−2, and a capacitance retention rate of 94% after 10,000 cycles at a current density of 40 mA cm−2. This indicates that the NiCo-LDH material prepared by multi-step electrodeposition method has good capacitance performance, providing a simple and time-saving method for manufacturing large-scale multi-step electrodeposition of adhesive-free supercapacitor electrodes.

Robust Graphene-based Aerogel for Integrated 3D Asymmetric Supercapacitors with High Energy Density.

Three-dimensional asymmetric supercapacitors (3D ASC) have garnered significant attention due to their high operating window, theoretical energy density, and circularity. However, the practical application of 3D electrode materials is limited by brittleness and excessive dead volume. Therefore, we propose a controlled contraction strategy that regulates the pore structure of 3D electrode materials, eliminates dead volume in the 3D skeleton structure, and enhances mechanical strength. In this study to obtain reduced graphene oxide/manganese dioxide (rGO/MnO2) and reduced graphene oxide/carbon nanotube (rGO/CNT) composite aerogels with a stable and compact structure. MnO2 and CNT as nanogaskets, preventing the self-stacking of graphene nanosheets during the shrinkage process. Additionally, the high specific capacitor nanogaskets significantly enhance the specific energy density of the rGO aerogel electrode. The prepared rGO/MnO2//rGO/CNT 3D ASC exhibits a high mass-specific capacitance of 216.15 F g-1, a high mass energy density of 74 Wh kg-1 at 3.5 A g-1, and maintains a retention rate of capacitance at 99.89 % after undergoing 10,000 cycles of charge and discharge at 5 A g-1. The versatile and integrated assembly of 3D ASC units is achieved through the utilization of the robust mechanical structure of rGO-based aerogel electrodes, employing a mortise and tenon structural design.

High mass-loading CoO@NiCo-LDH//FeNiS flexible supercapacitor with high energy density and fast kinetics

The rapidly growing market of portable and wearable smart electronics has created strong interest in flexible electrode materials with high specific capacitance and fast charging/discharging properties. However, high mass-specific capacitance active materials are often limited by the low areal mass-loading required. High areal capacity electrodes can make more efficient use of the limited internal space of these miniature devices by minimizing the volume and weight taken by current collectors and separators. Herein, a method is proposed to prepare a nickel–cobalt layered double hydroxide binder-free cathode on flexible carbon cloth with a mass loading of 20 mg cm−2. This core–shell hybrid structure prepared using a MOF self-sacrificing template, achieves a high energy density using thick electrodes while improving their slow kinetics by enhancing both the ion diffusion process and charge transfer dynamics. The areal capacitance reaches a staggering 4.42 mAh cm−2 (31.79 F cm−2) at a current density of 8 mA cm−2. Furthermore, a one-step hydrothermal method to prepare the FeNi-S anode (1.67 mAh cm−2, 2 mA cm−2) is proposed. Upon assembling with the gel electrolyte, this flexible device possesses an impressive energy density of 3.29 mW h cm−2 (3 mW cm−2). It can readily supply energy to watches, wireless e-paper, LEDs, and can be anticipated to be widely used in next-generation high-performance portable and wearable devices.

A superior electrolyte composite with high conductivity and strength based on alkali-activated slag and polyacrylamide for structural supercapacitor

In the time to come, structural supercapacitors have broad prospects in large-scale and construction structure energy storage. But the contradiction between ionic conductivity and mechanical performances of structural electrolytes still exists. Here, a novel polyacrylamide/alkali-activated slag (PAM/AAS) structural electrolyte composite is reported to attain a balance of high ionic conductivity and qualified compressive strength. The prepared PAM/AAS composite structural electrolytes show optimal properties with ionic conductivity of 55.01 mS/cm and compressive strength of 44.5 MPa in the dry state and 36.9 MPa after soaked in aqueous solution of 2 M KOH. Structural supercapacitor assembled with rGO electrodes has high mass specific capacitance of 285.35 F/g at 1 mA/cm2, energy density of 2.48 Wh/kg and power density of 59.54 W/kg, and favorable cycle life. The results of PAM/AAS composite structural electrolytes are superior to those in latest researches, attesting its vast application potential in construction structure energy storage.

Preparation of amorphous silver-ear-shaped CoNi2S4 cathode materials by sacrificial template method and its performance in asymmetric supercapacitors

Three-dimensional amorphous silver lug-like CoNi2S4 electrode materials have been designed and synthesised by the sacrificial template method. Through a clever combination of Ni2+ induced template deficiency and sulphidation reactions, the rearrangement of the electronic structure can be promoted, generating more defects. The Ni element-doped electrode significantly improves the capacitance due to the bimetallic synergy and has a high mass specific capacitance of 1351 F g −1 at a current density of 4 A g −1. The specific capacitance was 1111 F g −1 at a current density of 20 A g −1, showing an excellent multiplicative performance (82.2%).

Two-dimensional transition metal carbide (Ti0.5V0.5)3C2Tx MXene as high performance electrode for flexible supercapacitor

MXenes have gained widespread interest in flexible supercapacitor due to their rich electrochemical activity and free-standing electrode structure. However, it has been a challenge to obtain an electrode with high (mass and volumetric) specific capacitance, high rate and long cycle life simultaneously. Herein, we have prepared a novel few-layer double transition metal carbide (Ti0.5V0.5)3C2Tx MXene. Multivalent V atoms with high electrochemical activity were constructed in stable M3C2-type MXene to obtain the (Ti0.5V0.5)3C2Tx electrode with excellent performance in flexible supercapacitors. The (Ti0.5V0.5)3C2Tx film has an excellent specific capacitance of 387F g−1 (1625 mF cm−3) at 1.0 A g−1, and 267 F g−1 (1121 mF cm−3) even at a high current density of 20.0 A g−1, demonstrating superior rate performance (69%). Moreover, the capacitance of the (Ti0.5V0.5)3C2Tx film remains stable during 100,000 cycles. The symmetric supercapacitor assembled using (Ti0.5V0.5)3C2Tx film has high energy and power densities, up to 5.6 Wh kg−1 and 5210.3 W kg−1. And the all-solid-state (Ti0.5V0.5)3C2Tx flexible SC maintains stable electrochemical performance after 200 bending cycles. This work shows the huge potential of (Ti0.5V0.5)3C2Tx in flexible supercapacitor, and provides a new idea for the design of high performance flexible electrodes.

Preparation of pleated flower-like manganese-cobalt-silicate bimetallic electrode materials for supercapacitors

Transition metal silicates (TMSS) have been studied as potential electrode materials for rechargeable batteries and supercapacitors (SCs), and delicate structural design can further enhance the capacity performance and cycling stability of TMSS electrode materials. Herein, a bimetallic doping modulation strategy was employed, and a novel metal-silicate structure was constructed to obtain SC anode materials with excellent electrochemical properties. Manganese cobalt silicate (AMMnCo) with a pleated flower-like structure was obtained by the reaction of Mn2+ and Co2+ with acid-etched montmorillonite (AM) substrates using a simple hydrothermal method. The benign, competitive bimetallic mechanism accelerates the growth of manganese silicate and cobalt silicate on treated montmorillonite (MMT), which results in more folded ion-transport channels on the lamellae and improves the electrochemical properties of the transition-metal silicates. AMMnCo exhibits a higher specific capacitance (979F·g−1/0.5 A·g−1) and better cycling performance (84 %/10,000 cycles) than its monometallic counterparts. Additionally, AMMnCo//AC (where AC is activated carbon), a hybrid supercapacitor (HSC) device, has a high mass specific capacitance and an energy density reaching 13.7 Wh·kg−1 at a power density of 246.9 W·kg−1. Therefore, AMMnCo is a prospective electrode material for high-performance SC applications.

Construction and application in solid-state asymmetric supercapacitors of gladiolus-like NiSe/CoSe/Ni3Se2 hierarchical nanocomposite with synergistic structural advantages

Gladiolus-like NiSe/CoSe/Ni3Se2 hierarchical nanocomposite supported by nickel foams (NF) was synthesized for the first time by the mixed solvothermal method. Structural characterizations show that the obtained hierarchical nanocomposite forms from the dense growth of NiSe and CoSe nanosheets around Ni3Se2 nanowires. This novel gladiolus-like nanostructure supported by NF possesses the remarkable synergistic structural advantages from 1D/2D nanostructures and porous metallic substrate. It makes the gladiolus-like NiSe/CoSe/Ni3Se2 hierarchical nanocomposite with the excellent electrochemical properties, i.e.: high mass specific capacitance of 1666 F g−1 at 0.5 A g−1, high rate performance of 56.7 % at 2.5 A g−1, and 85.19 % capacitance retention after 5000 cycles. These phenomena are ascribled to the hierarchical nanostructure, heterozygous mettalic atoms, high conductivity, and significant synergistic effect. Subsequently, solid-state asymmetric supercapacitors are built up by using gladiolus-like NiSe/CoSe/Ni3Se2 hierarchical nanocomposite and active carbon as the pair electrodes. This solid-state device has a high areal energy density of 0.33 mWh cm−2 at areal power density of 7 mW cm−2, 80.11 % capacitance retention after 10,000 cycles, and promising commercial value. Thus, the present work not only demonstrates that gladiolus-like NiSe/CoSe/Ni3Se2 hierarchical nanocomposite is the promising electrochemical materials, but also offers a new device for solid-state, small, and smart electronic products. The present groundbreaking work also offers a novel strategy for enhancing the electrochemical capability of supercapacitor electrodes by designing ingenious nanostructures.

Regenerated Silk Fibroin-Modified Soft Graphene Aerogels for Supercapacitive Stress Sensors

The regenerated silk fibroin is developed to soft graphene aerogels for application in stress sensor. The resultant graphene aerogel owns a low density of 14.1 mg cm−3 with high mass specific capacitance of 128.4 F g−1. When a single aerogel serving as elastic medium, a supercapacitive stress sensor is established to offer high sensitivity of 0.73 kPa−1 in ranging 0.01–10 kPa. In contract, the sensor based on original graphene aerogel just shows a sensitivity of 0.04 kPa−1. Further, the sensing stability of the optimized sensor can retain 87% under constant pressure intensity of 1 kPa for 1000 cycles. The soft effect can be attributed to the regenerated silk fibroin by intercalation in preparation, and the simulated results show that the stress response originated from the variation of ion concentration in the electrochemical system.

Effect of current on electrodeposited MnO2 as supercapacitor and lithium-ion battery electrode

In this work, we prepared MnO2 electrodes by ultrasonic-assisted electrodeposition to study the influence of current density on the surface morphology and electrochemical performances of the MnO2, as well as the electrochemical performances of MnO2 electrodes of supercapacitors and lithium-ion batteries. The prepared MnO2 electrodes showed nanorod morphology, and the grain size changeed and presented a different distribution at different current densities. The electrochemical performances of as-prepared electrodes under a current density of 7 mA cm−2 shows a high mass specific capacitance of 415.4 F g−1 at the current density of 1 A g−1 in supercapacitors and 818.1 mA h·g−1 at 1 A g−1 after 200 cycles in lithium-ion batteries.

Nitrogen plasma activation of cactus-like MnO2 grown on carbon cloth for high-mass loading asymmetric supercapacitors

The electrochemical performance of high theoretical capacitance MnO2 is usually restricted to low mass loading electrode due to the slower electron/ion diffusion kinetics in dense electrodes. Defect engineering has been supposed to an effective way to improve the capacitive performance of transition metal oxides. Herein, cactus-like structure MnO2 was grown on carbon cloth (CC) and treated with N2-plasma to obtain the N-MnO2 electrode with high mass loading of 12 mg cm−2. Benefiting from the hierarchical structure and rich oxygen vacancies, the as-prepared N-MnO2 electrode delivered a high mass specific capacitance of 443F g−1 and a high areal capacitance of 5320 mF cm−2. Furthermore, the N-MnO2 electrode released an excellent rate capability with 71.8% capacitance retention at 20 mA cm−2 as well as gratifying cycling life with 96 % capacitance retention after 8 000 cycles at 20 mA cm−2. Moreover, an asymmetrical supercapacitor device assembled by N-MnO2 and activated CC can achieve a high energy density of 0.56 mWh cm−2 (46 Wh kg−1) at the power density of 5.14 mW cm−2 (420 W kg−1) with good cycle stability. Such facile N2-plasma treatment for defect engineering shows great potential in the rational design for advanced supercapacitor electrodes with high mass loading.

Spontaneous three-dimensional self-assembly of MXene and graphene for impressive energy and rate performance pseudocapacitors

Integration of pseudocapacitive nanomaterials within graphene based 3D-hydrogel network has shown suitable synergist in rate performance energy storage, but implementing the same with MXene through conventional heat involved processing is challenging due to its oxidation prone surface. Herein, we present a purely room temperature casting based approach to develop 3D-hydrogel hybrids of MXene and graphene (MGH) via metallic zinc particles induced spontaneous gelation, avoiding oxidation possibility. MGH was used as supercapacitor electrode that exhibits high mass specific capacitance of 357 F g–1 at 10 mV s–1, and excellent capacity retention of 95.6% after 10000 charge-discharge cycles. MGH was used as negative electrode to develop asymmetric supercapacitor, in combination with polyaniline (PANI)-graphene hybrid hydrogel (PGH) as positive electrode, that delivers a maximum energy density of 30.3 Wh kg–1 and a power density of 1.13 kW kg–1 with excellent capacity retention over 10000 cycles. In comparison to compact electrodes where pseudocapacitive materials cannot display their faradic activity with full potential, the hydrated porous network of MXene-graphene hydrogels with continuous channels permit the electrolyte ions to efficiently access MXene and PANI, thereby displaying high gravimetric and rate performance. MXene-graphene hydrogels, developed via this facile and cost effective protocol, are also attractive candidate for wide application areas that requires 3D porous structure.

Investigation of the supercapacitance of ruthenium-based/ hemp stem activated carbon

This work presents the synthesis of amorphous ruthenium-based/hemp stem activated carbon (HSAC) composites by a liquid phase co-precipitation method. It is the first time that a solution of tetramethylammonium bicarbonate is used as the precipitant. The result reveals that the as-synthesized ruthenium oxide particles are small in size and homogenously distributed on the activated carbon surface. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) results show that the ruthenium oxide/HSAC composite has a high mass-specific capacitance (652.79 F g−1 at 5 mV s−1) and excellent rate capability. Electrochemical impedance spectroscopy (EIS) experiments further demonstrate that it has a low device series resistance (0.653 Ω), which has a great enhancement by contrast with the state-of-the-art previous reports. High specific capacitance, outstanding cycling stability, and facile preparation conditions make the electrode material potentially promising for energy storage and conversion devices.

Preparation and enhanced supercapacitance performance of carbonized silk by feeding silkworms MoO2 nanoparticles

As a key building block to power flexible electronics, there is need for the development of flexible current collectors. Bombyx mori silk, a traditional textile, attracts increasing attention for its potential application in flexible electronics and is a promising raw material for flexible carbon electrodes in current collector fabrication. In this work, molybdenum dioxide nanoparticles (MoO2 NPs), which possess chemical stability and high mass specific capacitance, was used as a feed additive and combined with mulberry leaves to raise silkworms. It was found that the MoO2 NPs were embedded within the silk fibers, which endowed the resulting silk with favorable features for electrochemical energy storage in flexible electronics. After carbonization, the specific capacitance of electrodes prepared with silk from the MoO2 NPs feeding group, with a mass/volume ratio of 5 g/L, was enhanced from 100 F/g to 245 F/g at a current density of 0.2 A/g. Impressively, the electrodes show high coulombic efficiency with excellent stability. This work demonstrates the possibility of producing carbonized silk with superior properties for developing silk-based flexible electrodes for use in energy storage devices in a large-scale, green, low-cost way.

Three-dimensional carbon nanotubes/iron oxyhydroxide shell/core hybrid as a binder-free electrode for the flexible supercapacitor

Carbon nanotubes/iron oxyhydroxide (CNTs/FeOOH) three-dimensional hybrid with shell/core nanostructure is designed as a binder-free electrode for the flexible supercapacitor (SC) application. The coiled and dense CNT forest is preferentially fabricated on flexible carbon fiber cloth (CC) by chemical vapor deposition (CVD) and employed as a highly conductive carrier for electrodeposition growth of FeOOH. The average diameter and length of the single CNT are 30–60 nm and 2–3 μm. The shell/core structured CNTs/FeOOH three-dimensional hybrid maintains the consistent interconnecting network morphology, contributing to overcoming the problem of poor conductivity of FeOOH and the transmission of electron channels and the diffusion of electrolyte ions. The CNTs/FeOOH hybrid exhibits a high mass-specific capacitance of 824 F g−1 (or 0.59 F cm−2) in 1 M Na2SO4 electrolyte at 0.5 mA cm−2. By increasing the FeOOH deposition weight, the enhanced area-specific capacitance of 0.892 F cm−2 (or 564 F g−1) is obtained at 0.5 mA cm−2, and the enhanced capacitance retention can reach 96% after 3000 charge/discharge cycles. Besides, a flexible SC is fabricated using the CNTs/FeOOH hybrid electrode and carboxymethyl cellulose (CMC)/Na2SO4 gel electrolyte. The SC displays an energy density as high as 13.33 Wh kg−1 at a power density of 1000 W kg−1. The SC device shows large bending deformation, and these SC devices pack can drive a red diode to work. These results provide such a shell/core structured CNTs/FeOOH three-dimensional hybrid that can be used as potential and low-cost electrode material for flexible SC.

Construction of carbon nanorods supported hydrothermal carbon and carbon fiber from waste biomass straw for high strength supercapacitor

The development of high-performance flexible supercapacitor using biomass wastes as raw materials to overcome the high manufacturing cost has attracted excellent interest. Herein, a hierarchical structure of carbon nanorods supported hydrothermal carbons and carbon fibers (CNR/HTC/CFs) with superior electrochemical performance as well as high strength is successfully designed for the first-time using waste straw as a sustainable and economic carbon resource. The straw pyrolysis gases after purification are introduced to support the formation of high specific surface area CNRs via a simple vapor phase growth process. The CNR/HTC/CFs exhibit high mass specific capacitance of 269.47 F g−1 under the scan rate of 3 mV s−1 in three-electrode system. A high energy density of 15.54 Wh kg−1 with the power density of 0.49 kW kg−1 was obtained in the as-assembled all solid-state supercapacitor device with gel electrolyte, whose value retains as high as 6.99 Wh kg−1 with the power density of 10.01 kW kg−1. The tensile strength of the finally fibers can reach up to 2743 ± 467 MPa, which is sufficient for many practical industrial applications. This work provides a feasible synthetic strategy using sustainable biomass waste as raw materials to prepare high strength and capacitance energy storage devices.

CoP nanoprism arrays: Pseudocapacitive behavior on the electrode-electrolyte interface and electrochemical application as an anode material for supercapacitors

The self-supported transition metal phosphide with specific morphology and architecture has been investigated extensively due to excellent conductivity, stability, and morphologic diversity. In the work, cobalt phosphide with special nanoprism arrays in-situ grown on the nickel foam skeleton forms a typical three-dimensional open structure. It exhibits notable electrochemical performance when employed as an anode in a single electrode system, which owns a high mass specific capacitance (1349 F g−1 at the current density of 1 A g−1, which is the highest compared with that in the extant literature), good rate capacity and cycle stability. Besides, pseudocapacitive contribution to the entire capacity is up to about 77%, revealing the nature of high mass specific capacitance of the as-prepared CoP@NF as the working electrode. Furthermore, an asymmetrical supercapacitor device has been fabricated using CoP@NF as an anode and CMK-3@NF as a cathode. It can deliver a high power density of 325 W kg−1 at the energy density of 24 Wh kg−1 and the specific capacitance retention of about 93% after 5000 cycles. The results demonstrate that CoP@NF with special nanoprism arrays is a promising potential candidate as the electrode material of supercapacitors and other energy-storing applications.

Novel hybrid supercapacitor based on ferrocenyl modified graphene quantum dot and polypyrrole nanocomposite

Graphene quantum dots (GQDs) have attracted great attention because of its unique properties which originate from its small dimensions. This work is the first report of ferrocenyl modified Graphene Quantum Dot (GQD-Fc) which performed as supercapacitor. In order to improve the electrode conductivity, the GQD-Fc physically mixed with Polypyrrole and obtained nanocomposite was used as electrode material. Benefiting from the high specific surface area of GQD as well as the presence of nitrogen and iron-rich contents in the synthesized nanocomposite, prepared electrodes reveal the good capacity behaviors include high mass specific capacitance of 284.01 F g−1 (2.5 A g−1), the 86% retention of initial capacitance after 5000 cycles in a three-electrode system along with the remarkable energy density (81.79 Wh kg−1) and power density (18.17 kW kg−1). Based on the obtained results, ferrocenyl modified GQD expected to be a competitive candidate for new kind of capacitive material as high-performance supercapacitor electrode.