Capacitance Of Supercapacitor Research Articles

Hierarchical Co0.6Mn0.4Se@CoMo layered double hydroxide ultra-thin nanosheet for high performance hybrid supercapacitor

Designing the novel electrode materials with compositing diverse active components and unique microstructures is an effective strategy to enhance the energy storage capacity of supercapacitors. In this work, the hierarchical composite Co0.6Mn0.4Se@CoMo-LDH, which consists of Co0.6Mn0.4Se nanosheets and CoMo-LDH, is grown directly on nickel foam by hydrothermal reaction, solvothermal selenization reaction and electrodeposition. The prepared material has unique hierarchical interconnected nanosheets, which not only increases the contact area with the electrolyte and enhances the electron transfer ability, but also enables the high capacity through the interaction between active materials. Benefiting from these advantages, the prepared material shows a high specific capacity of 1405.2 C g−1 (at current density of 1 A g−1) and an excellent capacity retention of 88.2% after 10000 cycles. Moreover, the hybrid supercapacitor assembled by Co0.6Mn0.4Se@CoMo-LDH and active carbon achieves a high energy density of 71.4 Wh kg−1 at the power density of 1.13 kW kg−1. Meanwhile, the device shows a cycle performance of 106.2% over 10000 cycles. Because of the superior electrochemical performance, Co0.6Mn0.4Se@CoMo-LDH composites electrode has a tremendous potential in upcoming energy storage technologies.

Iron-cobalt-nickel-copper-zinc (FeCoNiCuZn) high entropy alloy as positive electrode for high specific capacitance supercapacitor

High entropy alloys (HEAs) are new-generation supercapacitive materials providing multiple active sites for enhanced electrochemical redox reactions. In this regard, we have successfully synthesized HEA comprising of Iron-Cobalt-Nickel-Copper-Zinc (Fe-Co-Ni-Cu-Zn) using induction melting and reduced its dimensions via ball milling. The ball-milled Fe-Co-Ni-Cu-Zn sample is throughly characterized by using basic structural and morphological techniques. A positive electrode is fabricated for supercapacitor application. This quinary HEA shows the highest gravimetric capacitance of 325.17 F g − 1 at 1 A g − 1 (3 M potassium hydroxide, aqueous electrolyte) in single electrode system. The asymmetric device also demonstrates energy density of 23.82 Wh kg−1 by consuming a power density of 325 W kg−1. Additionally, theoretical studies (DFT) shows that the electronic distribution of quinary Fe-Co-Ni-Cu-Zn elements in the alloy enhances chemical stability which is the reason for higher specific capacitance.

High-performance MoSe2/rGO composites based on interface and phase engineering for all-solid-state symmetric supercapacitors

The energy storage capacity of supercapacitors depends on the electrode structure of the active material and its properties related to capacitance. Improving the properties of active materials through engineering strategies is essential to obtain high-energy supercapacitors. Here, we combine interface and phase engineering to overcome the inherent limitations of MoSe2 and improve their charge storage capacity. MoSe2 was anchored to reduced graphene oxide (rGO) using a simple hydrothermal method to form a heterogeneous structure. This approach provided a large number of electrode/electrolyte contact interfaces. The synergistic interaction of MoSe2 and rGO also enhances the overall electrical conductivity and structural stability. At the same time, the phase conversion of the MoSe2 material is triggered by the intercalation of Na+ ions to increasethe layer spacing and, thus, the charge storage capacity. In summary, MoSe2/rGO were prepared by engineering strategies with a high specific capacitance of 169.3 F g−1 at 0.5 A g−1. The assembled all-solid-state symmetrical supercapacitor (ASSC) devices have good cycling stability (83.1 % over 10,000 cycles) and potential practical applicability.

Titanium germanium carbide MAX phase electrocatalysts for supercapacitors and alkaline water electrolysis processes

Developing electrochemically active, stable, and low-cost electrocatalysts for electrochemical devices is a significant breakthrough. Accordingly, MAX phases, emerging three-dimensional materials, are considered outstanding candidates due to their excellent electrocatalytic and electrochemical properties. Herein, the titanium germanium carbide (Ti3GeC2) MAX phase with a layered structure manufactured through reactive sintering was regarded as the electrocatalyst. In the current work, the electrocatalytic activity of the Ti3GeC2 was investigated for electrochemical devices. It was observed that adding activated carbon to the Ti3GeC2 enhances the conductivity and active area, leading to an excellent specific capacitance (349 Fg-1) for supercapacitors. Also, the capacitance of Ti3GeC2 was increased by increasing the number of cyclic voltammetry cycles. In another application, Ti3GeC2 showed substantial activity for hydrogen and oxygen evolution reactions in alkaline media. As a result, the alkaline water electrolysis system using Ti3GeC2 showed the highest current density of 10 mA cm−2 at 1.36 V and outstanding stability over 400 cycles.

An amide based polyvinyl alcohol / protic ionic liquid (PVA / PIL) gel electrolyte for supercapacitor applications

An aqueous gel based on polyvinyl alcohol (PVA) and a mixture of two nitrate salts, namely lithium nitrate (LiNO3) and pyrrolidinium nitrate, PIL (PyrrNO3) was prepared and used as an electrolyte. The gel electrolyte shows a high conductivity in the presence of formamide (FMD), which was studied as an organic additive in the gel at 5–400 % with respect to the salt content. Their electrochemical behaviors were examined by cyclic voltammetry, galvanostatic charge-discharge and an impedance technique at room temperature (17 °C). The 100 % of amide in the gel has shown a maximum ionic conductivity of 33 × 10−3 and 11.2 × 10−3 Scm−1 at 17 °C and −20 °C respectively. A two electrode supercapacitor (SC) was assembled and analyzed. The cycle life is improved by the additive over the bare gel, as evidenced by the galvanostatic cycling. The specific discharge capacitance of SC based on the 100 % of amide can be used for delivering 34.2, 27.3 and 21 Fg−1 at 1.5 V under a constant current density of 50, 100 and 500 mAg−1 respectively. Moreover, the SC efficiency was maintained at 95 %, and above as well as the capacity loss was minimized in the presence of the additive. This quasi solid-state supercapacitor will be capable of delivering an energy density of 12–13 Whkg−1and maximum power density of 0.60 kWkg−1 at 2 V. The results confirm that the capacitive enhancement is at the lower limit of the FMD.

Study of [EMIM] [EtSO4] ionic liquid-based gel polymer electrolyte mediated with hydroquinone redox additive for flexible supercapacitors

Gel Polymer Electrolytes (GPEs) are considered as suitable candidates in the design of energy storage devices like flexible supercapacitors due to their higher safety and flexibility. Incorporating small quantity of redox additives in GPE significantly improves their conductivity and is considered as an innovative method to enhance the capacitance of supercapacitors, because both electrolyte and electrode materials contribute to the capacitance. In this work, performance of Flexible Supercapacitor's (FSCs) using symmetrical Laser Induced Graphene (LIG) as electrodes and ionic liquid 1-Ethyl-3-Methylimidazolium Ethyl Sulfate [EMIM] [EtSO4] incorporated in Gel Polymer Electrolyte (GPE) with and without redox additive Hydroquinone (HQ) is presented. Upon electrochemical characterization using Galvanostatic Charge Discharge (GCD), it was found that the FSC with redox additive showed highest areal capacitance and energy density of 15.1 mFcm−2 and 1.54 μWhcm−2 respectively and FSC without redox additive showed an areal capacitance and energy density of 1.94 mFcm−2 and 0.14 μWhcm−2 respectively at 2 mAcm−2. The device with redox additive also showed 100 % columbic efficiency after 50 cycles and maintained 80 % capacitance for 5000 charge-discharge cycles. Additionally, the electrolyte with the redox additive showed superior conductivity of 10.8 mScm−1, demonstrating that modifying electrolyte by adding redox additive has been a simple yet effective method to enhance the overall performance of FSCs. Also, the synthesized LIG was characterized by X-ray Diffraction (XRD), Raman and Scanning Electron Microscopy techniques which confirmed the formation of bi-layer porous graphene.

An Optimal Configuration Model for Supercapacitor Capacity to Suppress Wind Power Fluctuations

This paper presents an optimization configuration scheme for energy storage capacity by taking into account the operational characteristics of supercapacitors. The scheme utilizes Empirical Mode Decomposition (EMD) to address power fluctuations during the integration of wind power into the grid. To begin with, the wind power data undergoes EMD to decompose it into different-order intrinsic mode functions. These functions are then reconstructed as low-frequency components and high-frequency components. The low-frequency components are directly connected to the grid, while the high-frequency components are employed for power smoothing through energy storage. Subsequently, the impact of various wind power grid limits on the directly connected power is compared to identify the optimal value. A model is established to configure the capacity of supercapacitors, aiming to mitigate wind power fluctuations. The model considers an objective function that minimizes the sum of energy storage investment and operational maintenance costs, along with the compensation cost associated with wind power fluctuation opportunities. Finally, the proposed model’s effectiveness and economic feasibility are validated through case studies. This ensures that the model’s efficacy in reducing power fluctuations and its viability from a financial standpoint are thoroughly examined.

Effect of simple cubic, face-centered cubic, and body-centered cubic-electrodes on the electric double layer capacitance of supercapacitors

The continuum theory has been used to analyze the polarization, ion crowding, and electrostatic forces of the electric double layer in the electrode materials having simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC) morphologies. The study manifests the effect of thickness of electrodes, electrode’s particle size, and porosity on electric double-layer specific capacitance (EDLC). Electrochemical interference and the specific capacitance depend on the packing factor. The larger particle size decreases the specific capacitance, but porosity increases due to more surface area. Due to symmetry, SC, BCC, and FCC morphologies have 1, 3, and 5 spheres in a unit cell. The number of unit cells is varied from 1 to 100 in model 1 to analyze the effect of electrode thickness. Model 2 has three unit cells to understand the effect of porosity, and only pore lengths are varied. The critical thickness of the electrodes is the integer multiples of 1.71 μm in all the morphologies. The Stern layer-specific capacitance is 167.6 μF cm−2 in all cases. The EDLC in BCC is around 5.6–7.6 μF cm−2 in the steady state that is intermediate between SC and FCC morphologies. The more dense packing of carbon particles in a unit cell increases the energy storage capabilities of electrodes. The average electrode permittivity slightly decreases due to the combined effect of the high electric field, status of polarization, and electrode particle size. The least optical transmission of electrodes is 98.35%.

An artificial neural network model for capacitance prediction of porous carbon-based supercapacitor electrodes

Among energy storage devices, the last decades have witnessed the rapid spread of usage of carbon-based electrodes for electric double-layer capacitors (EDLCs) due to their large surface area, low cost, and high porosity. It is crucial to develop an accurate and efficient forecasting model for electrochemical performance to reduce the time needed for making suitable designs and choosing testing electrode materials. As a result, the use of machine learning (ML) approaches in creating a predicting model for the capacitance of carbon-based supercapacitors looks critical and provides the electrode characteristics' relative relevance. Data extracted from nearly a hundred published experimental research papers to select supercapacitors with certain electrode morphologies such as mesoporous, nanoporous, microporous, and hierarchical porous carbon electrode. The data was examined using machine learning techniques to predict the supercapacitor's specific capacitance (F/g). Electrode material structural qualities and various physicochemical test features such as electrolyte material, pore volume, and specific surface area. Electrochemical test features acquired via electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge (GCD) test investigations for the same purpose include: cell configuration, current density, applied potential window, charge-transfer resistance (RCT), and equivalent series resistance (ESR) were used as input features to predict the corresponding capacitance performance. In the present study, Lasso, Support Vector Machine Regression (SVMR), and Artificial Neural Networks (ANN) with different structures were examined to predict the capacitance of the supercapacitor. The exhibition of the ML models measured concerning the root mean square error (RMSE), the correlation between expected yield and yield provided by the system. The developed ANN model with RMSE, MAE, and R values of 30.82, 46.5624 and 0.89537, respectively, provides outcomes for the prediction that are highly accurate compared to other models created for this purpose. According to the analysis of the input features done using the SHAP (SHapley Additive exPlanations) framework, the specific surface area had the biggest impact on the ANN model.

Alpha-Ni(OH)2 nanoflakes incorporated on MOF derived ZnO hybrid Faradaic arrays for high-performance asymmetric supercapacitor

Elegant transition metal oxide nanocomposites with modified structures are required to enhance specific capacitance of supercapacitors. A core–shell embedded ZnO@Ni(OH)2 nanocomposite electrode with porous nano-flakes morphology has been synthesised by low temperature wet chemical method. Ni(OH)2 nano flakes are decorated on ZnO derived from Zeolitic Imidazolate Framework-8 (ZIF-8) by a facile technique. The wurtzite hexagonal phase of ZnO and α-Ni(OH)2 are evidenced by XRD analysis. FTIR spectral analysis confirms the Zn-O, Ni-OH and interlamellar hydrogen bonded Ni(OH)2 layers of the ZnO @Ni(OH)2 sample. FESEM and elemental mapping results reveal core–shell embedded architecture of ZnO@Ni(OH)2. The presence of primary elements such as Zn, Ni, and O of ZnO, Ni(OH)2 and their oxidation states are confirmed in XPS results with the existence of binding energies corresponding to Zn 2P3/2, Zn 2P1/2, Ni 2P3/2, Ni 2P1/2, and O 1s peaks. The ZnO@Ni(OH)2 nanocomposite electrode in a three electrode system exhibits a high specific capacitance of 510F g−1 at 1 A g−1 and a good cyclability for 2000 cycles at 10 A g−1 with 77% capacity retention. Also, in the case of an asymmetrical supercapacitor, it was delivered the specific capacitance of 45F g−1 at 1 A g−1. Furthermore, a good cyclability for 10,000 cycles with capacity retention of 76.25%, and a high power density of 1595.5 W kg−1 are obtained. The excellent electrochemical behaviour of ZnO@Ni(OH)2 nanocomposite favoured by the core–shell embedded architecture is discussed as a futuristic pseudocapacitor energy storage material.

Enhancing gravimetric and volumetric capacitance in supercapacitors with nanostructured partially graphitic activated carbon

The volumetric and gravimetric capacitance of supercapacitors are primarily influenced by the specific surface area and porosity required for the formation of electric double layers in the electrode material, and these capacitance are known to have a trade-off relationship. To address this issue, additional capacitance enhancement mechanisms are needed not only at the electrode material surface but also within the limited mass and volume, which can be achieved through structural improvements of the material. In this study, we produce partially graphitic activated carbon with low specific surface area but nano-sized crystalline regions from petroleum pitch, a soft carbon precursor. This approach allows for improvements in gravimetric capacitance. The resulting activated carbon with a specific surface area of 1122 m2 g−1 exhibits volumetric specific capacitance of 27.9 F cc−1 and gravimetric specific capacitance of 38 F g−1 in an organic electrolyte, indicating a new direction for electrode materials in supercapacitors.

Large-scale production of 18650 cylindrical supercapacitors: Effects of separators, electrode thickness, electrolyte additives, and testing protocols

Although supercapcitors have been widely studied, large-scale 18650 cylindrical supercapacitor cells have been rarely investigated and reported. Here, we investigated the effects of polymer separators, electrode thickness, electrolyte additives, testing protocols, reproducibility, and stability of the supercapacitors at the large-scale pilot plant. The supercapacitor cells with polyethylene (PE) and Al2O3-coated PE separators are good at low and high specific currents, respectively. The Al2O3-coated PE exhibits better stability than the one with the PE separator. The supercapacitor with a thickness of 250 μm has a cell capacitance of over 120 F from 100 to 1000 mA, which is higher than that of the other cells studied in this work. Also, the cell capacitances of supercapacitors can be enhanced by having redox mediator additives. 25 mM hydroquinone and ferrocene methanol are the optimized concentrations. We also found that the cell capacitance and equivalent series resistance of the supercapacitors are sensitive to the testing protocol, for which the highest capacitance was observed using the IEC62391-1 standard method, followed by the Maxwell method and conventional galvanostatic charge discharge method without dwell time. High reproducibility and stability of the as-fabricated supercapacitors in this work may lead to the further development of practical large-scale supercapcitors in the future.

Hydrogel and carbon nanostructures based supercapacitor: Initial steps toward green supercapatteries

Efficient distribution and storage of energy are crucial to mitigate the effects of climate crisis; fortunately, scientific community is making accelerated actions to improve and create prototypes allowing a sustainable use of energy.In particular, we will center our discussion on results showing the enhancement of energy and power densities of a supercapacitor that allows rapid energy delivery working with a nontoxic electrolyte. The use of nanostructures (carbon nanotubes and graphene) allows to increase the supercapacitor capacitance, by inherently increasing surface area, with an important impact on energy power density. The broadening of the electrochemical window of the hydrogel based electrolyte also has a positive influence on power density.Herein is depicted a green prototype with good power density (1779.41 W kg−1), typical of supercapacitors, but also with good energy density (105.37 W h kg−1), with a cycling life (2000 cycles) superior of some hydrogel electrolyte based supercapacitors, but still far from an efficient system. Those results have to be improved, but are promissory to combine the best characteristics of supercapacitors and rechargeable batteries, into a green supercapattery.

Modeling capacitance of carbon-based supercapacitors by artificial neural networks

Carbon-based electrodes effectively promote the specific capacitance of the supercapacitors. The Specific capacitance of carbon-based electrodes has been modeled using an artificial neural network (ANN) with the backpropagation learning algorithm. This paper describes the creation of an ANN model to interpret how voltage window (V), ID/IG, N/O-dopings (at. %), pore size (nm), and specific surface area (m2/g) parameters influence the specific capacitance (F/g). The experimentation has been carried out with several ANN architectures to achieve the best fit between the inputs and output. The model predictions (adj.R2 = 0.99) and estimation of the isolated effect of independent variables, such as voltage window, cannot be varied independently in practice. The results from the ANN model were consistent with the existing theory and reasonable in estimating the specific capacitance beyond the scope of the experimental data. The model successfully expresses the specific capacitance of carbon-based supercapacitors as a function of physiochemical and electrochemical process variables and can be used to design electrical storage devices.

Porous Co3O4/VS4/rGO-SDBS@NF nanoflower as a high performance supercapacitor electrode

Maximizing the performance of supercapacitors requires the design of high-conductivity, stable, and cost-effective electrode materials. The current study presents a novel solution in the form of self-supporting binder-free hierarchical Co3O4/VS4/rGO-SDBS@NF composite electrodes. These electrodes are fabricated using a facile and efficient two-step hydrothermal process. The growth of Co3O4 particles on VS4/rGO-SDBS flower-shaped nanosheet arrays on nickel foam substrates results in a sufficient contraction and expansion space distribution during charge and discharge. The Co3O4/VS4/rGO-SDBS@NF composite shows a specific capacitance of 2620 F g−1 at 1 A g−1, which is significantly compared to the VS4/rGO-SDBS@NF composite at 284 F g−1 in a 6 M KOH solution. Furthermore, the as-grown electrode Co3O4/VS4/rGO-SDBS@NF composite displays excellent cycling stability, with 97.4 % of its initial capacitance retained after 5000 cycles. In summary, the utilization of a simple and accessible manufacturing and synthesis method, absence of binders, in-situ growth technique, achievement of a special morphology with effective electrochemistry, excellent supercapacitor capacity, and high cyclic stability demonstrate significant improvements compared to recent works. These results provide a new perspective for the selection and synthesis of materials and the design and fabrication of electrodes for supercapacitors as energy storage devices.

Insight into the Desolvation of Organic Electrolyte Cations with Propylene Carbonate as a Solvent in Flat Pores: A First-Principles Calculation

Supercapacitors have many applications in new energy and other high-tech fields. The desolvation effect on ions affects the capacity size of supercapacitors, and there are few relevant studies published in this field at present. In this experiment, bilayer graphene (BG) with a layer spacing of 4–10 Å was used as a model of flat pores and was calculated with first-principles calculations, which can effectively simulate the adsorption behaviour of porous carbon. The reaction energies of ions, propylene carbonate, and ionic complexes in bilayer graphene with different layer spacings were calculated, and the desolvation behaviour of lithium salt cations (Li+), tetraethyl quaternary ammonium salt cations (TEA+), triethyl methyl quaternary ammonium salt cations (TEMA+), and bipyrrolidinium quaternary ammonium salt cations (SBP+) was investigated. The calculation was based on density functional compact bound (DFTB+) software. The calculated results show that in the stacked system, the complete desolvation size of the TEA+ reaches 5.6 Å, the complete desolvation size of the TEMA+ reaches 4.9 Å, the complete desolvation size of the SBP+ reaches 4.8 Å, and the complete desolvation size of the Li+ reaches 5.4 Å, with the organic electrolyte cations showing a positive trend in the complete desolvation size as the ion radius increases. An in-depth analysis of the data shows that Li+, TEA+, TEMA+, and SBP+ ion radii play a dominant role in the size of desolvation. The results of this paper provide an effective aid for the selection of organic electrolytes to increase the capacity of supercapacitors.

Transforming Chimney Soot via Stochastic Polymerization for Active Electrode Coating

A polymerization procedure is presented to increase the molecular weight of hydrocarbons in household chimney soot without thermal treatment at high temperatures. Pristine soot was subject to chlorination, with half of it treated with magnesium (Mg-plates) to create random-type Grignard reagents (R-Mg-Cl) in diethyl ether media. Mixing the Grignard reagent and the rest of the halogenated soot material created new C-C bonds, thus increasing the molecular weight of the final product. The obtained stochastically polymerized soot (SPS) was investigated using Raman spectroscopy, FTIR spectroscopy and XPS and was subjected to electrochemical testing as an assembled supercapacitor with a KOH electrolyte. Results show significant carbon structure differences due to the chemical procedures and newly created functional groups in the soot. Such functional groups could increase the capacity of supercapacitors, creating pseudo-capacitance by participating in redox reactions. The results also unveiled removing any random contaminations in the pristine soot and obtaining a more uniform final product containing hydrocarbons with longer chains, thus increasing the molecular weight.

A Review on Recent Progress Achieved in Boron Carbon Nitride Nanomaterials for Supercapacitor Applications

Supercapacitors are regarded as reliable energy storage devices to alleviate the energy crisis and environmental pollution. However, the relatively low capacitance and low energy density limit the practical application of supercapacitors. In this context, boron carbon nitride (BCN) nanomaterials have been extensively studied in the past decade due to their chemical and thermal stability, high mechanical strength, as well as tunable bandgap. The specific capacitance and energy density of supercapacitors can be significantly improved by fabricating nanostructured BCN-based electrode materials. In this review, the recent advances in the application of BCN-based materials in supercapacitors is presented. Strategies such as structure design, porosity/defect engineering, and hybrid nanostructure construction to boost the electrochemical performance of BCN-based materials are provided and, finally, promising research directions for novel energy storage materials are proposed.

Design and synthesis of K-doped tremella-like δ-MnO2 for high-performance supercapacitor

The development of K-doped δ-MnO2 is an effective strategy to achieve a significant improvement in capacitance for MnO2-based supercapacitors. In this paper, we prepared a series of K-doped δ-MnO2 through the redox reaction between KMnO4 and MnCl2·4H2O with the assistance of KOH and acetone. The morphology and K content can be easily controlled by adjusting the amount of MnCl2·4H2O. The optimal sample not only has a tremella-like structure assembled from leaf-like nanosheets but also has the highest K content. This fascinating structure has following advantages: 1) The two-dimensional nanosheets can provide a large surface (specific surface area of 92.7 m2 g−1) for ion adsorption and ion diffusion; 2) The three-dimensional structure can avoid the accumulation of nanosheets, and its robust structure is difficult to be destroyed, which is conducive to improving cycling stability. Combining the advantages of the presence of large amounts of K+, i.e., the significant increase in electrical conductivity and ion intercalation sites, the sample exhibited superior electrochemical performance, such as the specific capacitance of 726.0 and 283.7 F g−1 at 1.0 A g−1 in KOH electrolyte and Na2SO4 electrolyte, respectively. Furthermore, the assembled K-doped δ-MnO2//activated carbon asymmetric supercapacitor with KOH electrolyte displayed an energy density of 24.38 Wh kg−1, whereas that with Na2SO4 electrolyte displayed a high energy density of 45.64 Wh kg−1.

Co(OH)2 nanoneedles grown on Cu/NF current collector with high areal capacitance for supercapacitors

Despite the demand for high energy-density supercapacitors has been realized when transition metal hydroxides are used as electrode materials, the ion diffusion dynamics are still limited by its high impedance. In this work, Cu is deposited on nickel foam (NF) by filtered cathodic vacuum arc (FCVA) technology to serve as an ion-diffusion-favored surface state. Co(OH)2 synthesized hydrothermally on this Cu/NF exhibits remarkably enhanced electrochemical properties compared with Co(OH)2 grown on pristine NF. The resultant electrode can deliver a large area capacity of 0.772 C cm−2 at 1 mA cm−2 and retain 80.92% of initial capacitance after 4000 cycles. Moreover, an assembled asymmetric supercapacitor shows a high energy density of 0.086 mW cm−2 at 0.4 mWh cm−2 with a long lifespan (80.67% retention after 3000 cycles). Our strategy may provide a new insight to prepare electrodes for assembling high areal capacitance supercapacitors.