Electrode For Asymmetric Supercapacitors Research Articles

Structural design and fabrication of metal vanadate hydrates for wearable electronic applications

The structural design of electroactive materials including rich profits of high capacitance/capacity and exalted durability is of considerable importance in the development of high-performance wearable energy storage technologies. Herein, a simple and single-step hydrothermal approach is demonstrated to design hierarchical feathers-like microsheet arrays for asymmetric supercapacitors (ASCs) with stable cycling performance. The preparation is carried out at low temperatures without any annealing process, and the as-designed nickel/cobalt vanadate hydrates supported on conductive carbon cloth textile are endowed with the unique architecture of feathers-like microsheets, which allows for the effective contact of active materials, rapid ion diffusion, easy electrolyte penetration, and fast electron transfer. Considering these merits in amalgamation, the Ni0.33Co0.67 vanadate hydrate active material shows a superior areal/specific capacity value of 373.9 µAh cm−2/140 mAh g−1 with outstanding cycling performance (100,000 cycles) than those in the design of mono NiV and CoV hydrates as well as the other fabricated electrode (Ni:Co ratio) materials. Furthermore, the Ni0.33Co0.67 vanadate hydrate active material, when employed as a positive electrode for ASCs, demonstrates excellent electrochemical performance. The assembled ASC exhibits high energy and power density values of 0.19 mWh cm−2 and 2.04 mW cm−2, respectively along with remarkable cycling retention of 82.2% after the completion of 100,000 cycles. Also, the as-assembled device was tested by powering different wearable electronics. This work creates a new pathway for the fabrication of single-step Ni-Co vanadate hydrates for durable electrochemical energy storage applications.

Cubic-architectured tungsten sulfide @ Cu-Fe bimetallic electrodes for dye-sensitized solar cells, hybrid supercapacitors, and piezoelectric nanogenerators

Designing an efficient multifunctional electrode material for energy conversion, generation, and storage application was cutting-edge in energy research for the advanced integrated device. In that view, WS2 @CuFe nano box composites were constructed using the Kirkendall effect and employed as the electrode in dye-sensitized solar cells (DSSCs), asymmetric supercapacitors (ASC), and piezoelectric nanogenerators (PENG). The WS2 @CuFe − 2 nano boxes were employed as the counter electrode in DSSC and attained a power conversion efficiency of 5.4%, surpassing the performance of platinum counter electrode device (4.4%). In ASC, benefiting from the nano box morphology, the intensive utilization of surface area by electrolytes, and the synergistic contribution of WS2 @CuFe − 2 nano box results in an outstanding specific capacitance of 467 F/g at 1 A/g current density. The WS2 @CuFe − 2 //AC device owing to the induced surface area provides a high energy density of 44.45 Wh/kg and a high-power density of 1420 W/kg with columbic efficiency of 98.62%. The PENG was investigated for practical application by applying an external compression force of 50 N, which delivered an impressive self-charging potential of 167 mV generated by the piezoelectric compartment. The results prove the comprehensive application of WS2 @CuFe nano boxes serving as the all-in-one electrode for constructing sophisticated neoteric electronic devices.

Ti3C2Tx MXene integrated hollow carbon nanofibers with polypyrrole layers for MOF-derived freestanding electrodes of flexible asymmetric supercapacitors

Effective customization of Ti3C2Tx MXenes by electrospinning technique is crucial for the preparation of freestanding/flexible electrodes exhibiting enhanced performance in supercapacitors. Herein, we prepared MXenes containing hollow carbon nanofibers (MXHCNF) by co-axial electrospinning, and the inside-out of MXHCNF is decorated with polypyrrole layers (PPy@MXHCNF), which is sufficiently flexible, conductive, and highly functionalized with a unique trilayer morphology. Using the self-designed electroactive PPy@MXHCNF, a ZnCoMOF is homogeneously grown. The as-prepared bimetallic MOF on PPy@MXHCNF is used as a common precursor with which to fabricate the positive (ZCO@PPy@MXHCNF) and negative (NPC@MXHCNF) electrodes by a controlled heat treatment process using a “two from one” strategy. The freestanding positive and negative electrodes provide specific capacitances of 1567.5 F g−1 and 477.2 F g−1 at 1 A g−1, respectively, with high capacitance retention, cyclic stability, and coulombic efficiency. A flexible asymmetric device (ZCO@PPy@MXHCNF//NPC@MXHCNF) is assembled, and it exhibits an energy density of 61.3 Wh kg−1 at a power density of 796.8 W kg−1 and 92.8% capacitance retention after 10,000 GCD cycles. This work provides a unique approach involving MXene modification, polypyrrole decorated electrospun MXHCNFs as efficient substrates for freestanding electrodes, and the use of bimetallic MOF as a common strategic route for both positive and negative electrodes in flexible asymmetric supercapacitors.

In-situ formation of morphology-controlled cobalt vanadate on CoO urchin-like microspheres as asymmetric supercapacitor electrode

The exploration of desirable structure is of positive significance for energy storage materials. In particular, morphology design of the electrode materials greatly affects the electrochemical performance. Herein, controllable synthesis of cobalt vanadate with various structures on 3D urchin-like CoO microspheres is achieved. By precisely controlling the vanadium content, we obtain cobalt vanadate with diverse structures, including 3D hollow nanocages, 3D nanocages connected to polygonal nanosheets, 2D honeycomb-like nanosheets, and 2D irregular nanosheets on CoO microspheres. Adjusting the content and structure of cobalt vanadate allows us to optimize its electrochemical performance. The optimized cobalt vanadate with a structure of hollow cages connected to polygonal nanosheets supported by CoO skeleton exhibits a superior energy storage capacity, and the final CoO@Co2V2O7 electrode delivers an outstanding areal specific capacitance of 7.58 F cm−2 at 2 mA cm−2. In addition, the fabricated asymmetric supercapacitor (ASC) possesses an excellent energy density of 0.45 mWh cm−2 at 1.60 mW cm−2, and an outstanding capacitance retention of 84.65% after 5000 cycles. In a word, the proposed strategy of structure-controllable cobalt vanadate supported by CoO is promising for supercapacitor electrode materials.

Rational construction of NiCo double-hydroxide/cobalt hydroxycarbonate as advanced electrode for high performance asymmetric supercapacitor

In this present paper, a novel nickel‑cobalt double hydroxide/cobalt carbonate hydroxide nanosheets composite (NiCo-DH/NSs) with excellent electrochemical performances is successfully constructed through a rational design of the structure and composition. Cobalt carbonate hydroxide (Co2(OH)2CO3) with a nanosheet morphology and low surface energy is firstly prepared by an simple one-step hydrothermal approach. Then the electroconductive NSs are exploited as a substrate for the in-situ growth of metal-organic framework (MOF). The pre-synthesized MOF/NSs composite is further alkali treated to obtain the final composite material by a “crystal-crystal conversion” strategy. Due to proper structure and synergistic effect between two components, the prepared NiCo-DH/NSs as positive electrode material delivers a high specific capacity (586 mAh g−1 at 1 A g−1) and outstanding rate performance (92.15 % capacity retention at 10 A g−1). In addition, a high specific capacitance of negative electrode material (BiOBr microsphere) is also successfully prepared. As a result, the assembled NiCo-DH/NSs//BiOBr asymmetric supercapacitor (ASC) device exhibits ultrahigh energy density of 67.74 Wh kg−1 at power density of 775.03 W kg−1.

MOFs-derived niobium oxide nanoparticles/carbon nanofiber hybrid paper as flexible binder-free electrode for solid-state asymmetric supercapacitors

For the first time, a bottom-up approach was adopted to prepare free-standing orthorhombic Nb2O5-anchored carbon nanofibers (Nb2O5 @CNFs) hybrid paper via in-situ solvothermal synthesis of Nb-metal organic framework@CNFs hybrid and subsequent pyrolysis process. The nanocrystalline Nb2O5 decorated on the CNF surfaces improved the charge storage performance through synergistic effect between porous CNFs (EDLC) and Nb2O5 (pseudocapacitance). Moreover, the high surface area and core-shell structure of Nb2O5 @CNF hybrid reduce diffusion limitations and facilitate ionic transport. The Nb2O5 @CNF hybrid paper as a binder-free electrode delivered greater specific capacitance of 633.6 F/g (975.7 F/cm3) in 1 M H2SO4, compared to Li2SO4 electrolyte (524.3 F/g) at 0.5 A/g. However, the Nb2O5 @CNF electrode showed better cycling stability in neutral Li2SO4 electrolyte than in acidic H2SO4 electrolyte. The solid-state asymmetric supercapacitor (ASC) based on Nb2O5 @CNF paper and activated carbon (AC) electrodes delivered higher energy density of 62.1 Wh kg−1 at 292.7 W kg−1 in Li2SO4 electrolyte due to a wider working potential window (0–1.5 V), compared to H2SO4 electrolyte (55 Wh kg−1). The Li2SO4-based ASC cell is also capable of producing an energy density of up to 45.6 Wh kg−1, even at a high-power density of up to 5853.6 W kg−1. The as-assembled ASC demonstrated low self-discharge rate as well as excellent bending stability, indicating its excellent prospects in real-life applications.

Efficient Self-Powered Overall Water Splitting by Ni4 Mo/MoO2 Heterogeneous Nanorods Trifunctional Electrocatalysts.

The exploration of cost-effective multifunctional electrodes with high activity toward energy storage and conversion systems, such as self-powered alkaline water electrolysis, is very meaningful, although studies remain quite limited. Herein, a heterogeneous nickel-molybdenum (NiMo)-based electrode is fabricated for the first time as a trifunctional electrode for asymmetric supercapacitor (ASC), hydrogen evolution reaction, and oxygen evolution reaction. The trifunctional electrode consists of Ni4 Mo and MoO2 (denoted Ni4 Mo/MoO2 ) with hierarchical nanorod heterostructure and abundant heterogeneous nanointerfaces creating sufficient active sites and efficient charge transfer for achieving high performance self-power electrochemical devices. The ASC consists of the as-prepared Ni4 Mo/MoO2 positive electrode, showing a broad potential window of 1.6V, and a maximum energy density of 115.6Whkg-1 , while the alkaline overall water splitting (OWS) assembled using the as-prepared Ni4 Mo/MoO2 as bifunctional catalysts only requires a low cell voltage of 1.48V to achieve a current density of 10mAcm-2 in aqueous alkaline electrolyte. Finally, by integrating the Ni4 Mo/MoO2 -based ASC and OWS devices, an aqueous self-powered OWS is assembled, which self-power the OWS to generate hydrogen gas and oxygen gas, verifying great potential of the as-prepared Ni4 Mo/MoO2 for sustainable and renewable energy storage and conversion system.

Unique hierarchical architecture of SnO2 hexagonal interconnected nanolayered arrays as negative electrode for high performance asymmetric supercapacitors

In this research, we report unique hierarchical structures of SnO2 hexagonal interconnected nanolayered arrays (HINLA) fabricated on the carbon cloth (SnO2 HINLA@CC) by a facile electrochemical deposition technique. The structural, morphological evolution and electrochemical properties of as prepared SnO2 HINLA@CC are explored as negative electrode of SCs. SnO2 HINLA@CC has been tested in negative potential widow of −1.0-0 V and demonstrated the high specific capacitance of 325 F g−1 at 1 A g−1, much superior when compared to the previously reported data for SnO2. The EIS analysis confirmed the charge transfer kinetics of SnO2 HINLA@CC, with significant stability due to favorable morphology for swift response. Capacitance retention plot confirmed no structural degradation or pulverization for negative electrode even after 5000 galvanostatic charge with 88.6% capacitance retention. Such high performances of SnO2 HINLA@CC as negative electrode make it an ideal candidate to be useful in ASCs. Moreover, a 2.2 V aqueous ASC has been constructed by employing Na0·5MnO2 nanowall arrays (NWAs) as cathode and SnO2 HINLA@CC as anode. In particular, the 2.2 V Na0·5MnO2 NWAs@CC//SnO2 HINLA@CC ASC has demonstrated the superior energy density of ∼73 Wh kg−1, significant rate capability and excellent cycling ability, outperforming the previously reported SnO2-based ASCs. Present work provides new opportunities for developing promising high-voltage aqueous ASCs with excellent energy density.

Nickel-doped CuO/Cu/Cu2O nanocomposite as an efficient electrode for electrochemical non-enzymatic glucose sensor and asymmetric supercapacitor

Nickel-doped CuO/Cu/Cu2O nanocomposite as an efficient electrode for electrochemical non-enzymatic glucose sensor and asymmetric supercapacitor

Metalloids (B, Si) and non-metal (N, P, S) doped graphene nanosheet as a supercapacitor electrode: A density functional theory study

Metalloids [Boron (B), Silicon (Si)] and Non -metals [Nitrogen (N), Phosphorus (P), Sulfur (S)] doped graphene nanosheets were considered for alternative lightweight electrode materials in energy storage device applications. The density functional theory studies were performed to investigate the structural stability, charge density distribution, excessive surface charge density, and quantum capacitance of doped graphene nanosheets. It is found that the structures are stable with negative formation energy, and the graphene nanosheet doped with P and S shows protrusion forming a pyramidal shape along the planar graphene nanosheet to maintain stability. Further, the doping of atoms into the graphene nanosheet introduced a minimal bandgap with a shift in the Fermi level, either into the conduction band or valence band, depending on the dopant type. This appearance of bandgap is attributed to the breaking of the symmetry in the graphene sublattice. Meanwhile, based on the type and concentration of dopant, localized and delocalized states are formed near the Fermi level. It is also found that the formation of a localized state near the Fermi level has profoundly improved the excessive surface charge density and quantum capacitance. The S – doped graphene nanosheet was observed to exhibit an excellent quantum capacitance of 38.88 μFcm−2 compared to all other structures and it can be used as a suitable light-weight electrode for asymmetric supercapacitors.

Metal organic framework derived CoNiOOH nanorods anchored on carbon cloth as electrodes for asymmetric supercapacitors

Metal-organic frameworks (MOFs) with high porosity, large specific surface area, and versatile structures are an outstanding electrode material for supercapacitors, but the electrochemical energy storage performance of MOFs is limited due to their low electrical conductivity and the difficulty of growing uniformly on carbon cloth conductive substrate. Herein, the CoNi-MOF nanorods successfully anchor on carbon cloth by growing the Ni(OH)2 nanosheets on carbon cloth as precursors, and by the electrochemical induction strategy, the solid CoNi-MOF intermediates convert into porous hollow CoNiOOH nanorods. The CoNiOOH-2 electrode shows an ultrahigh area specific capacitance of 11.6F/cm2 at 2 mA/cm2. For assembling an asymmetric supercapacitor (ASC), the nitrogen doped activated carbon cloth (NAC) is prepared as the negative electrode. The CoNiOOH-2//NAC ASC device delivers a high energy density of 0.732 mWh/cm2 at 1.6 mW/cm2, and exhibits excellent cycling stability with 98.59% capacitance retention after 10,000 cycles. This work provides a novel way to grow MOF materials on carbon cloth and prepare self-supported electrodes with excellent performance, which has a broad application prospect.

Effect of thermal annealing on electrochemical and morphological properties of printed NiO electrodes for flexible asymmetric micro-supercapacitor applications

We report the effects of thermal annealing on screen-printed NiO electrodes for asymmetric battery-type supercapacitors on flexible substrates. Ni(OH)2 was synthesized and annealed at 300 °C, 400 °C, 500 °C, 600 °C, 700 °C and 800 °C to obtain six morphologically diverse NiO samples. FE-SEM, XRD, BET, and four-probe measurements were used to investigate their morphology, crystallinity, surface area, and conductivity, respectively. Six symmetric supercapacitors were screen-printed on a PET substrate with 1 M H2SO4 electrolyte to probe their electrochemical properties. NiO annealed at 400 °C (NiO-400) demonstrated the highest areal capacitance of 19.54 mF/cm2 coupled with reduced charge-transfer resistance, consistent with the highly porous yet continuous structure observed via FE-SEM and BET surface analysis. With this, an inter-digital asymmetric supercapacitor with NiO-400 cathode and graphene anode was fabricated to demonstrate high areal capacitance of 26.42 mF/cm2, a wide potential window of 1.5 V (at 97.3% coulombic efficiency) and excellent flexibility with 96.4% retention (180°) after 1000 cycles.

Fabrication of Flexible Poly(m-aminophenol)/Vanadium Pentoxide/Graphene Ternary Nanocomposite Film as a Positive Electrode for Solid-State Asymmetric Supercapacitors.

In this study, poly(m-aminophenol) (PmAP) has been investigated as a multi-functional conductive supercapacitor binder to replace the conventional non-conductive binder, namely, poly(vinylene difluoride) (PVDF). The kye benefits of using PmAP are that it is easily soluble in common organic solvent and has good film-forming properties, and also its chemical functionalities can be involved in pseudocapacitive reactions to boost the capacitance performance of the electrode. A new ternary nanocomposite film based on vanadium pentoxide (V2O5), amino-functionalized graphene (amino-FG) and PmAP was fabricated via hydrothermal growth of V2O5 nanoparticles on graphene surfaces and then blending with PmAP/DMSO and solution casting. The electrochemical performances of V2O5/amino-FG/PmAP nanocomposite were evaluated in two different electrolytes, such as KCl and Li2SO4, and compared with those of V2O5/amino-FG nanocomposite with PVDF binder. The cyclic voltametric (CV) results of the V2O5/amino-FG/PmAP nanocomposite exhibited strong pseudocapacitive responses from the V2O5 and PmAP phases, while the faradaic redox reactions on the V2O5/amino-FG/PVDF electrode were suppressed by the inferior conductivity of the PVDF. The V2O5/amino-FG/PmAP electrode delivered a 5-fold greater specific capacitance than the V2O5/amino-FG/PVDF electrode. Solid-state asymmetric supercapacitors (ASCs) were assembled with V2O5/amino-FG/PmAP film as a positive electrode, and their electrochemical properties were examined in both KCl and Li2SO4 electrolytes. Although the KCl electrolyte-based ASC has greater specific capacitance, the Li2SO4 electrolyte-based ASC delivers a higher energy density of 51.6 Wh/kg and superior cycling stability.

One-pot achievement of La2O3/MnO2 nanocomposites as efficient electrodes for asymmetric supercapacitors

One-pot achievement of La2O3/MnO2 nanocomposites as efficient electrodes for asymmetric supercapacitors

Cyclic voltammetry activation for boosting the supercapacitance of trimetallic Ni-Co-Mn phosphides

Electrochemical activation has a great significance for enhancing the energy storage capability of electrode materials. To develop high-performance phosphides electrodes, herein, NF/MnCoMn-P (NCM-P) is fabricated by two-step method, and the contribution of cyclic voltammetry (CV) activation to electrochemical performance is revealed, as well as the activation mechanism. In the initial activation stage, NCM-P nanosheets are transformed into ultrathin NiCoMn-OH nanosheets. Meanwhile, hexagonal Ni(OH)2 nanosheets are generated, which greatly enhance the fraction of Ni. With an increase of CV cycle, vertical nanosheets arrays, petal structure, cracked structure and agglomerates are produced in sequence, accompanied with the capacitance attenuation. Among these structures, vertical nanosheets arrays obtained at 180 cycles deliver the highest capacitance of 2126 F g−1 (1063 C g−1) at 1 A g−1, about three times higher than that of NCM-P, which are considered as activation terminal. The microstructure evolution confirms that the activation essence of NCM-P is the generation, reassembly, swelling and gathering process of ultrathin hydroxides nanosheets. Furthermore, the activation mechanism of NiP layer on NF framework is proposed to explain the source of hexagonal Ni(OH)2. Serving as a positive electrode in asymmetric supercapacitor, activated NCM-P also presents a superior electrochemical performance, further reflecting the promising application potential of activated trimetallic phosphides.

Density functional theory studies on graphene/h-boron nitride hybrid nanosheets for supercapacitor electrode applications.

Pristine graphene (C32), hexagonal boron nitride (h-BN), and graphene/h-BN hybrid nanosheets were examined using density functional theory calculations in order to find their suitability as an electrode material for supercapacitor applications. The stability of the structure, charge density, electronic properties, and quantum capacitance of pristine graphene and graphene/h-BN hybrid nanosheets were studied. The structural optimization results reveal that all the nanosheets are stable with zero transverse displacement of atoms along the z-direction. Further, replacing the C-C pair with B-N altered the average bond length and angle, thereby maintaining structural stability. The interaction between graphene and h-BN is higher for C16B8N8 compared to other hybrid nanosheets because of the delocalized distribution of the electron density cloud. The doping of the B-N pair into the graphene nanosheet shifts the Fermi level into either the valence band or the conduction band based on the concentration of the B-N pair. Meanwhile, the effective mass is increased and is relatively high for the hybrid nanosheets with a localized state. The pristine B16N16 nanosheet exhibits a quantum capacitance of 31.539 μF cm-2, while among the hybrid nanosheets, the C4B14N14 nanosheet exhibits a maximum quantum capacitance of 22.518 μF cm-2, and from the outcomes, they are suitable as an electrode for asymmetric supercapacitors.

A bimetallic Fe-Mg MOF with a dual role as an electrode in asymmetric supercapacitors and an efficient electrocatalyst for hydrogen evolution reaction (HER).

In this work, a novel bimetallic Fe-Mg/MOF was synthesized through a cost-effective and rapid hydrothermal process. The structure, morphology, and composition were examined using X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy. Further, the Brunauer-Emmett-Teller (BET) measurement showed a 324 m2 g-1 surface area for Fe-Mg/MOF. The Fe-Mg/MOF achieved 1825 C g-1 capacity at 1.2 A g-1 current density, which is higher than simple Fe-MOF (1144 C g-1) and Mg-MOF (1401 C g-1). To assess the long-term stability of the asymmetric device, the bimetallic MOF supercapattery underwent 1000 charge/discharge cycles and retained 85% of its initial capacity. The energy and power densities were calculated to be 57 W h kg-1 and 2393 W kg-1, respectively. Additionally, Fe-Mg/MOF showed superior electrocatalytic performance in hydrogen evolution reaction (HER) by demonstrating a smaller Tafel slope of 51.43 mV dec-1. Our research lays the foundation for enhancing the efficiency of energy storage technologies, paving the way for more sustainable and robust energy solutions.

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

This work constructed recyclable Fe3O4/MWCNT/CNF composite nanopaper, exhibiting exceptional flexibility, high electrical conductivity, and extraordinary mass- and area-specific capacitances as the negative electrode.

Tuning the morphology and size of NiMoO4 nanoparticles anchored on reduced graphene oxide (rGO) nanosheets: The optimized hybrid electrodes for high energy density asymmetric supercapacitors

• Porous NiMoO 4 NPs/rGO composite has been prepared through a facile hydrothermal approach followed by thermal treatment. • NiMoO 4 NPs/rGO composite electrode exhibits high specific capacitance of 2056 Fg -1 and long cyclic stability of 91.4 % after 10,000 cycles. • An asymmetric supercapacitor with high energy density and long cycle life is fabricated. In order to improve the capacitive performance of supercapacitors, NiMoO 4 electrode materials were successfully prepared by a simple and low cost hydrothermal route, and the morphology, microstructure and properties of the materials were successfully optimized by adding reduced graphene oxide (rGO). Electrochemical and sophisticated physical property tests are used to examine the qualities of items. As a supercapacitor electrode material, the NiMoO 4 /rGO composite performed admirably. The specific capacitance reached 2056 Fg -1 at a current density of 2 Ag -1 , which is greater than standard NiMoO 4 at the same current density (788 Fg -1 ). After 1000 charge/discharge cycles, NiMoO 4 /rGO retains 91.1 % of its initial capacitance. NiMoO 4 /rGO composites can be used in asymmetric supercapacitors, and the asymmetric supercapacitor device offers a high power density (60. 2 Whkg -1 ) and energy density (750.5 Whkg -1 ) when used as the positive electrode and activated carbon as the negative electrode. A combination of mesoporous-NiMoO 4 nanoparticles with a high specific surface area and good interaction with conductive rGO is responsible for the improved electrochemical performance of NiMoO 4 /rGO.

Nanometric MnO2 and MnO2‐Graphene Oxide Materials Enabled by a Solvent‐Assisted Synthesis and Their Application in Asymmetric Supercapacitors

Conventional manganese oxide (MnO2)‐based supercapacitors struggle to achieve theoretical capacitance due to the material's low conductivity and large particle size. Consequently, researchers have improved MnO2's properties by incorporating conductive carbonaceous materials to obtain high‐performance composite materials. Herein, the full process of engineering a MnO2‐graphene oxide (GO) composite and its application as a positive electrode for asymmetric supercapacitors (ASC) is presented. First, GO using a novel gas expansion precursor allowing an efficient chemical exfoliation of pristine graphite is synthesized. Afterward, size‐weakened MnO2 nanoparticles are synthesized and deposited onto the GO sheets by a self‐assembly redox reaction method using different MnO2/GO mass ratios. Multiple characterization methods are used to investigate the textural and structural properties of each material. A general electrochemical characterization is conducted using a three‐electrode cell; therefore, the synthesized MnO2‐GO composite achieves 150 F g−1 at 10 mV s−1. Furthermore, an ASC in an aqueous electrolyte using GO and MnO2 or MnO2‐GO as negative and positive electrodes, respectively, is assembled. The fabricated ASC based on MnO2‐GO composite exhibits a high specific capacitance of 38 F g−1 at 1 A g−1, excellent cycling stability after 36 000 cycles, and a steady electrochemical impedance behavior after 120 h of floating.