High-performance Energy Storage Applications Research Articles

Multifunctional activated carbon derived from novel biomass for high-performance energy storage applications: A sustainable alternative to fossil-fuel-derived carbon

Biomass-derived activated carbon materials have been attracted as low-cost and sustainable electrode materials for energy storage applications. In this work, we synthesised activated carbon from black gram whole skin for the first time, and the used source is a cost-effective carbon precursor. Nitrogen and phosphorous doping in activated carbon improved electronic conductivity, surface area and porosity. In supercapacitor application, the nitrogen and phosphorous doped activated carbon sample showed a high specific capacitance of 425 F g−1 at 0.5 A g−1 and cycling stability of about 92.5 % capacitance retention even after 5000 cycles in a three-electrode system. The observed stable specific capacitance in a three-electrode system encouraged us to make a two-electrode symmetric device, showing a specific capacitance of 100 F g−1 at 0.5 A g−1 with a higher energy density of 20 Wh kg−1. In addition, the lithium storage capability of doped carbon showed good capacity of 750 mAh g−1 at 0.1 A g−1 with a reversible capacity of 687 mAh g−1 after 100 cycles. The hetero-atom doped activated carbon derived from black gram skin showed outstanding electrochemical performance towards supercapacitor and lithium battery application, indicating a potential alternative to fossil fuel-derived carbon.

Unveiling the potential of Na2FePO4F@PEG composite as cathode material for sodium-ion batteries

The economic and environmental advantages of Na2FePO4F fluorophosphate have positioned it as a highly promising cathode material for sodium-ion batteries (SIBs). This recognition stems from its demonstrated potential to address key challenges in energy storage systems, making it a subject of extensive research and studies.In this paper, the preparation of Na2FePO4F powder through a simplified, upscaling, and cost-effective approach that involves the direct use of phosphoric acid is described, aiming to evaluate its electrochemical performance. The obtained orthorhombic structure (S.G. Pbcn) is mixed with varying percentages of polyethylene glycol as a carbon source (15% and 20%) to generate large specific surfaces, improve electronic conductivity, and achieve an optimized carbon content for these materials. The 15% and 20% PEG-coated Na2FePO4F are evaluated at a 2 - 4 V voltage range at C/15 in Na-half cells using two electrolyte formulations: 5% FEC 1 M NaClO4:PC and 1 M NaPF6:PC. The NaPF6/FEC electrolyte exhibits better electrochemical characteristics and high cycling stability, especially in the case of the 15% PEG-coated material. These findings are also supported by the data from differential plots and rate capabilities, highlighting the potential of the coated material for applications in high-performance energy storage applications.

Facile synthesis and electrochemical investigation of graphitic carbon nitride/manganese dioxide incorporated polypyrrole nanocomposite for high-performance energy storage applications

Abstract Manganese dioxide (MnO2) nanoparticles were modified by graphitic carbon nitride (GCN) and polylpyrrole (Ppy) to enhance their electrochemical performance. The surface influence, crystalline structure, and electrochemical performance of the Ppy/GCN/MnO2 material were characterized and compared with those of pristine MnO2. It is found that surface modification can improve the structural stability of MnO2 without decreasing its available specific capacitance. The electrochemical properties of synthesized Ppy/GCN/MnO2 electrode were evaluated using cyclic voltammetry (CV) and AC impedance techniques in 5 M KOH electrolyte. Specific capacitances of 486, 815, 921, and 1377 F/g were obtained for MnO2, Ppy/MnO2, GCN/MnO2, and Ppy/GCN/MnO2, respectively, at 5 A/g. This improvement is attributed to the synergistic effect of GCN and Ppy in the Ppy/GCN/MnO2 electrode material. The Ppy/GCN/MnO2 electrode in KOH has average specific energy and specific power densities of 172 Wh kg−1 and 2065 W kg−1, respectively. Only 2 % of the capacitance’s initial value is lost after 10,000 cycles. The resulting Ppy/GCN/MnO2 nanocomposite had very stable and porous layered structures. This work demonstrates that Ppy/GCN/MnO2 nanomaterials exhibit good structural stability and electrochemical performance and are good materials for supercapacitor applications.

Rational Design of a Graphene Oxide–Coated Separator for Thermally and Mechanically Stable Li Metal Anode

Lithium-ion (Li-ion) batteries are widely used in high-performance energy storage applications because of their high energy density. However, safety concerns related to thermal runaway remain a significant challenge for Li-ion batteries. Electrolyte leakage and dendrite formation can trigger thermal runaway, and these factors typically damage traditional polyethylene (PE) separators. Consequently, these separators struggle under extreme conditions and fail to control dendrite growth. In this study, we proposed a solution by coating PE separators with graphene oxide (GO) layers. GO, as a ceramic material, provides superior thermal and mechanical stability compared with polymers. Moreover, GO-coated PE separators (GO-S) do not compromise the advantages of PE separators and effectively manage dendrite growth. In this study, the as-prepared GO-S exhibits excellent electrochemical properties in terms of high ionic conductivity, suppression of Li dendrite growth during charge/discharge process, and long-term cyclability for 7,000 h (3,500 cycles) as well as high thermal stability even after heat treatment of 100°C. Thus, we expect that this research can highlight the potential application of functionalized GO sheets in addressing the thermal and mechanical limitations of polymer-based separators, thereby enhancing the safety and reliability of Li-ion batteries.

Resolving the tradeoff between energy storage capacity and charge transfer kinetics of sulfur-doped carbon anodes for potassium ion batteries by pre-oxidation-anchored sulfurization

Sulfur-heteroatom doping is an effective approach to improve the capacity of carbon anodes for potassium-ion batteries due to the reversible K+-sulfur reaction. However, the random sulfur doping induces unresolved tradeoff between capacity and kinetics, which results from the fundamental difficulty in controllable sulfur incorporation using traditional approaches where breaking robust carbon-containing bonds is necessary. Herein, a pre-oxidation-anchored sulfurization approach is proposed to realize site-controlled and content-adjustable sulfur doping, demonstrating the optimum sulfur content of 9.8 at.% in sulfur-doped hollow carbon sphere (S-HCS). Intentional pre-oxidation introduces easy-to-break C-O/C-O-C bond-included oxygen-containing functional groups serving as anchoring sites for substitution with sulfur atoms. Consequently, S-HCS-9.8 % achieves superior performance for K+ storage (406.1 mA h g–1 at 0.1 A g–1, 112.6 mA h g–1 at 5 A g–1 and 170 mA h g–1 after 2,000 cycles at 2 A g–1). The enhanced electrochemical performances are attributed to the largest interlayer spacing and highest disorder degree resulting from the thiophene-sulfur-dominated configuration at high sulfur content, which realizes high structure reversibility and stable solid-electrolyte-interface layer. This work provides new insights and guiding principles for the development of heteroatom-doped carbon anodes for next-generation high-performance energy storage applications.

Ultrahigh energy storage performance in AN-based superparaelectric ceramics

Ceramics capacitors, especially featuring antiferroelectric (AFE) structure, are widely used in pulsed power electronic systems due to distinctive high-power density and external field stability. Lead-free AFE material AgNbO3 has seized substantial research attention owing to its unique temperature driven multi-level phase transitions, and many works have greatly improved the energy storage properties by engineering these temperature-dependent phase boundaries. In this work, an ever-unadopted strategy was proposed to modulate the relaxor structure in AgNbO3 by designing room-temperature (RT) superparaelectric phase via Bi incorporation into AN lattice matrix. Structural analysis shows M phase (space group Pbcm) evolves into O phase (space group Cmcm) with 12 mol.% Bi-substitution, breaking the long-range AFE order into polar nanoregions. Hence, an ultra-high recoverable energy density (7.6 J/cm3) and a high efficiency (79 %) are simultaneously achieved in the Ag0.64Bi0.12NbO3 ceramics under 52.2 kV/mm. Moreover, the excellent energy storage properties are accompanied with good temperature and frequency stability, with the variation of Wrec less than ± 15% (over 25–120 °C) and ± 10% (over 1–200 Hz) under 25 kV/mm, respectively. The novel approach reported herein provides a new guidance for designing AgNbO3-based and other AFE materials for high-performance energy storage applications.

Heteroatom doping carbon film derived from hyphae as a self-supporting cathode for advanced lithium sulfur batteries

Much attention has been paid to lithium sulfur battery due to its high energy density. However, low S loading and poor cycling stability have hindered their commercialization. In this work, a porous carbon film with rich heteroatom doping was prepared from the Penicillium chrysogenum hyphae film by freezing drying and high-temperature carbonization. Then the carbon film loaded polysulfide solution was utilized as a self-supporting cathode for Li-S batteries. The self-supporting cathode exhibited good rate performance (513.1 mAh/g at 1C) and improved cycling stability (more than 400 cycles) under a high current density (0.5C). This is mainly attributed to the abundant heteroatoms that provided active sites with superior adsorption ability for lithium polysulfide, which not only enhanced the cycling stability but also facilitated the conversion kinetics. Besides, the fibrous network morphology with affluent porous structures inherited from hyphae provided a large specific surface area and sufficient space for accommodating active substances. This work shows the great potential of hyphae derived porous carbon electrodes for high-performance energy storage applications.

Interconnected CoNi-Se Hollow Flakes through Reduced Graphene Oxide Sheets as a Cathode Material for Hybrid Supercapacitors.

Achieving a high energy density and long-cycle stability in energy storage devices demands competent electrochemical performance, often contingent on the innovative structural design of materials under investigation. This study explores the potential of transition metal selenide (TMSe), known for its remarkable activity, electronic conductivity, and stability in energy storage and conversion applications. The innovation lies in constructing hollow structures of binary metal selenide (CoNi-Se) at the surface of reduced graphene oxide (rGO) arranged in a three-dimensional (3D) morphology (CoNi-Se/rGO). The 3D interconnected rGO architecture works as a microcurrent collector, while porous CoNi-Se sheets originate the active redox centers. Electrochemical analysis of CoNi-Se/rGO based-electrode reveals a distinct faradic behavior, thereby resulting in a specific capacitance of 2957 F g-1 (1478.5 C g-1), surpassing the bare CoNi-Se with a value of 2149 F g-1 (1074.5 C g-1) at a current density of 1 A g-1. Both materials exhibit exceptional high-rate capabilities, retaining 83% of capacitance at 10 A g-1 compared to 1 A g-1. In a two-electrode coin cell system, the device achieves a high energy density of 73 Wh kg-1 at a power density of 1500 W kg-1, stating an impressive 90.4% capacitance retention even after enduring 20,000 cycles. This study underscores the CoNi-Se/rGO composite's promise as a superior electrode material for high-performance energy storage applications.

One-step synthesis and fabrication of ZrMo2O8 nanostructures as advanced electrode material for energy storage applications

Nanostructures of metal molybdates show great potential as high-performance electrode materials for the forthcoming development of energy storage devices. In present work, ZrMo2O8 nanostructure was constructed using a simple chemical procedure and followed by examination with the aid of several spectral and analytical tools. The supercapacitive properties of ZrMo2O8 electrode material were investigated using Cyclic voltammetry (CV), Galvanostatic charge–discharge (GCD) and Electrochemical Impedance Spectroscopy measurements (EIS). The as-prepared ZrMo2O8 nanostructures as supercapacitor (SC) electrode material exhibited pseudocapacitive performance with notable value of 288C g−1 at 1 A/g, significant cycling stability and 92.5% capacity retention with the coulombic efficiency of 87.4% even after 5000 GCD cycles at 1 A/g. The morphological investigations indicated that the higher Specific capacity (Cs) was primarily caused by the significant increase in active sites as well as active surface area. The Bode phase angle plot of ZrMo2O8 exhibited a low frequency intercept, with emphasis at approximately −52° phase angle, indicating a superior redox signature. The results infered that ZrMo2O8 nanostructures are promising candidates for high performance energy storage applications.

MOF Derived CoFe2O4@Carbon Nanofibers for Supercapacitor Application

This study presents the synthesis and electrochemical evaluation of MOF-derived CoFe2O4 nanoparticles anchored on carbon nanofibers (CoFe2O4@CNFs) for supercapacitor applications. By integrating hydrothermal and electrospinning techniques, we successfully fabricated CoFe2O4@CNFs with enhanced supercapacitive properties. The electrochemical performance of CoFe2O4@CNFs was rigorously assessed, revealing a remarkable specific capacitance of 527 F/g at a current density of 1 A/g. Additionally, the electrode demonstrated a power density of 234.93 W/kg and an energy density of 16.58 Wh/kg. These results highlight the synergistic effect of combining MOF-derived bimetallic transition metal oxides with carbon nanofibers, underscoring their potential in advancing supercapacitor technology. The findings suggest that CoFe2O4@CNFs can serve as a promising candidate for high-performance energy storage applications, offering a viable pathway to enhance the efficiency and capacity of supercapacitors.

Effectively coupling of SnSe2nanosheet with N, Se co-doped carbon nanofibers as self-standing anode for lithium-ion batteries.

Tin selenides possess layered structure and high theoretical capacity, which is considered as desirable anode material for lithium-ion batteries. However, its further development is limited by the low intrinsic electrical conductivity and sluggish reaction kinetics. Herein, a well-designed structure of SnSe2nanosheet attached on N, Se co-doped carbon nanofibers (SnSe2@CNFs) is fabricated as self-standing anodes for lithium-ion batteries. The integration of structural engineering and heteroatom doping enables accelerated electrons transfer and rapid ion diffusion for boosting Li+storage performance. Impressively, the flexible SnSe2@CNFs anodes exhibit inspiring capacity of 837.7 mAh g-1after 800 cycles at 1.2 C with coulombic efficiency almost 100% and superior rate performance 419.5 mAh g-1at 2.4 C. The kinetics analysis demonstrates the pseudocapacitive characteristic of SnSe2@CNFs promotes the storage property. This work sheds light on the hierarchical electrode construction towards high-performance energy storage applications.

Effect of clay on TiO2 embedded PMMA nanocomposite for high-performance energy storage application

Present work deals with the dielectric and electrochemical properties of PMMA/TiO2 and PMMA/TiO2@Clay nanocomposite prepared via a simple sol-gel method followed by ultrasonication. With pore diameters of 16.657 Å, ternary nanocomposites have an increased specific surface area of 28.88 m2/g. The significant dielectric properties are observed for PMMA/TiO2 and PMMA/TiO2@Clay nanocomposite with the highest dielectric constant ε′ of 3.66 × 103 and 1.45 × 103 and maximum dielectric loss ε″ of 1.7 and 1.9 at 1 kHz respectively. The PMMA/TiO2 nanocomposite exhibits the highest σac conductivity of 1.29 × 10−4 S/m and 6.85 × 10−2 S/m, whereas; the PMMA/TiO2@Clay nanocomposite demonstrates the highest σac conductivity of 1.47 × 10−4 S/m and 1.84 × 10−2 S/m at 1 kHz and 3 MHz, respectively. The manufactured device's highest specific capacitance is 364.13 F/g, which corresponds to an energy density of 129.26 Wh/kg and a power density of 2913.04 W/kg. Even after 5000 CV cycles, a 97 % capacitance retention is reported in the cyclic stability. The present work proves its virtue and competency towards superior energy storage applications.

Metal-free platforms for molecular thin films as high-performance supercapacitors.

Controlling chemical functionalization and achieving stable electrode-molecule interfaces for high-performance electrochemical energy storage applications remain challenging tasks. Herein, we present a simple, controllable, scalable, and versatile electrochemical modification approach of graphite rods (GRs) extracted from low-cost Eveready cells that were covalently modified with anthracene oligomers. The anthracene oligomers with a total layer thickness of ∼24 nm on the GR electrode yield a remarkable specific capacitance of ∼670 F g-1 with good galvanostatic charge-discharge cycling stability (10 000) recorded in 1 M H2SO4 electrolyte. Such a boost in capacitance is attributed mainly to two contributions: (i) an electrical double-layer at the anthracene oligomer/GR/electrolyte interfaces, and (ii) the proton-coupled electron transfer (PCET) reaction, which ensures a substantial faradaic contribution to the total capacitance. Due to the higher conductivity of the anthracene films, it possesses more azo groups (-N[double bond, length as m-dash]N-) during the electrochemical growth of the oligomer films compared to pyrene and naphthalene oligomers, which is key to PCET reactions. AC-based electrical studies unravel the in-depth charge interfacial electrical behavior of anthracene-grafted electrodes. Asymmetrical solid-state supercapacitor devices were made using anthracene-modified biomass-derived porous carbon, which showed improved performance with a specific capacitance of ∼155 F g-1 at 2 A g-1 with an energy density of 5.8 W h kg-1 at a high-power density of 2010 W kg-1 and powered LED lighting for a longer period. The present work provides a promising metal-free approach in developing organic thin-film hybrid capacitors.

Synergistic enhancement of electrochemical performance of NiFe2O4@Ni-MOF nanoflake hybrids for high-performance energy storage applications

In this study, a novel method is investigated for enhancing the electrochemical performance of MOFs, particularly Ni-MOFs, which have encountered challenges in energy storage applications owing to their limited electrical conductivity and stability.

Hydrothermal synthesis of an MoS2/MnO2 nanocomposite: a unique 3D-nanoflower/1D-nanorod structure for high-performance energy storage applications

In this study, an MoS2/MnO2 nanocomposite electrode with a novel 3D nanoflower/1D nanorod architecture is effectively synthesized using a straightforward, cost-effective hydrothermal process.

Borax cross-linked guar gum hydrogel-based self healing polymer electrolytes filled with ceramic nanofibers towards high-performance green energy storage applications

An inventive concept towards the implementation of green energy-storing devices is the synthesis of hydrogel-based gel electrolytes from biopolymers imbued with self-healing capabilities. However, these electrolytes have drawbacks, such as low mechanical stability due to inadequate cross-linking and limited ionic conductivity compared to synthetic polymers. This work develops and characterizes a flexible self-healing hydrogel polymer electrolytes (HPEs) based on guar gum (GG) hydrogel for use in energy storage devices. Hydrogel is prepared with silicon dioxide (SiO2) nanofibers dispersed into borax-bonding cross-linked guar gum. Propylene carbonate (PC) and diethyl carbonate (DC) in equal amounts and lithium perchlorate (LiClO4) are used as plasticizers and salt, respectively. It has been found that adding nanofibers to the hydrogel and spreading them there considerably increases the ionic conductivity as evaluated by ac impedance spectroscopy. When the nanofiber concentration is 5 wt% (wt%), the hydrogel electrolytes reach their maximum room temperature ionic conductivity of 4.3 × 10−3 S cm−1. XRD, FTIR, SEM, and XPS investigations are used to explain the enhanced conductivity caused by the dispersion of nanofibers. Nanofibers also improve the self-healing abilities of materials, as demonstrated by the fact that hydrogels loaded with 5 wt% nanofibers recover from deformation more quickly than hydrogels with lower nanofiber contents. Additionally, the dispersion of nanofibers enhances the hydrogel's mechanical and thermal properties. According to electrochemical investigations and linear sweep voltammetry (LSV) graphs, hydrogel electrolytes are stable up to 4.7 V. When compared to nanofiber-free hydrogels, nanofiber-integrated hydrogel electrolytes show more excellent interfacial stability. The developed self-healing hydrogel-based polymer electrolytes exhibit outstanding promise for a range of energy storage systems, opening the way for creating high-performance and environmentally friendly energy storage solutions.

Intercalation of C60 into MXene Multilayers: A Promising Approach for Enhancing the Electrochemical Properties of Electrode Materials for High-Performance Energy Storage Applications.

In this study, we report on the enhancement of the electrochemical properties of MXene by intercalating C60 nanoparticles between its layers. The aim was to increase the interlayer spacing of MXene, which has a direct effect on capacitance by allowing the electrolyte flow in the electrode. To achieve this, various concentrations of Ti3SiC2 (known as MXene) and C60 nanocomposites were prepared through a hydrothermal process under optimal conditions. The resulting composites were characterized by using X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, Raman spectroscopy, and cyclic voltammetry. Electrodes were fabricated using different concentrations of MXene and C60 nanocomposites, and current-voltage (I-V) measurements were performed at various scan rates to analyze the capacitance of pseudo supercapacitors. The results showed the highest capacitance of 348 F g1- for the nanocomposite with a composition of 90% MXene and 10% C60. We introduce MXene-C60 composites as promising electrode materials for supercapacitors and highlight their unique properties. Our work provides a new approach to designing high-performance electrode materials for supercapacitors, which can have significant implications for the development of efficient energy storage systems.

Multi-Parameter Optimization of Siloxene-PANI Composites for High-Performance and Flexible Energy Storage Application

The development of high-performance energy storage devices is crucial for various applications, such as electric vehicles, portable electronics, and renewable energy systems. Supercapacitors have emerged as a promising technology due to their high power density and long cycle life. However, their low energy density has limited their widespread application. To address this limitation, researchers have been exploring various strategies, including the use of new electrode materials and optimized electrode design. In this study, a high-energy-density energy storage device was developed using a composite material composed of siloxene and polyaniline (PANI) for flexible supercapacitor designs. Here, optimized material's surface area, pore distribution, and electronic transition, achieving a specific capacitance of 483 F/g at 1A/g in a three-electrode system using a 1 M H2SO4 electrolyte. The optimized material also exhibited a retention rate of 92.6% at 5A/g. The optimized siloxene-PANI composite material was then used to fabricate a flexible asymmetrical supercapacitor (SiP4//AC). The supercapacitor exhibited a high energy density of 19.7 Wh/kg at a power density of 248 W/kg, with a cyclic stability of 90.26% and a coulombic efficiency of 97%. The flexible design of the supercapacitor using the siloxene-PANI composite material allowed for its use in wearable electronics and other applications requiring high-performance, flexible energy storage devices. The study provides valuable insights into the development of energy storage devices with high energy density and high power density, which will pave the way for the practical application of supercapacitors in various fields.

Mxene/SnO2 QDs Heterostructure Based Separator Interlayer Enable Kinetically Boosted Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries have drawn much attention as potential next-generation energy storage technology. However, their practical implementation faces challenges related to the cathode and anode, including the sluggish reactions, shuttle effect and lithium dendrite growth. The design of an efficient separator interlayer has been proved to be effective in mitigating the lithium polysulfides (LiPSs) shuttling and suppressing the formation of lithium dendrites. Here, we report a novel ultrathin and laminar MXene/SnO2 quantum dots based Mott-Schottky heterostructure with abundant active sites at their hetero-boundaries as a separator interlayer. Such design combines highly polar SnO2, conductive MXene, and highly active heterojunctions, synergistically enabling strong anchoring of LiPSs, rapid electron transportation and efficient LiPSs catalytic conversion (See figure 1). Moreover, the interlayer exhibits excellent performance at the anode side by suppressing lithium dendrite growth due to its high Young's modulus. As a consequence, the incorporation of this ultrathin and weight-negligible separator interlayer has resulted in a significant capacity enhancement of at least 20 %. In addition, we achieved an area capacity exceeding 6 mAh/cm2 at a high sulfur loading of 7.5 mg/cm2 during cycling. These findings pave new ways for further advancements in Li-S batteries and highlight the potential of heterostructure catalysis for high-performance energy storage applications. Figure 1

Synthesis of hybrid SmMnO3/rGO nanocomposites for high performance energy storage applications

The reduction of renewable energy resources like fossil fuels leads to a focus on electrochemical energy storage systems, which are remarkable and sustainable in day-to-day life. Furthermore, the challenge in supercapacitors is to fabricate a hybrid energy storage device with high energy density and longer discharge time. Herein, the samarium manganese oxide/reduced graphene oxide nanocomposites (SmMnO3/rGO NCs) were synthesized via ultrasonic-assisted hydrothermal technique and their structure, vibrational modes, morphology, and elemental composition were investigated by X-ray diffraction (XRD), Raman, Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray Spectroscopy (EDX), High Resolution Transmission Electron Microscope (HRTEM), and Selected Area Electron Diffraction (SAED) analysis. Furthermore, the electrochemical activities were analyzed by Cyclic voltammetry (CV analysis), Galvanostatic charge-discharge (GCD analysis), and the Electrochemical impedance spectroscopy (EIS analysis). The CV study of SmMnO3/rGO NCs possesses a higher specific capacity (Cspecific) of 392.95 C/g at a 10 mV/s scan rate compared to SmMnO3. From Trasatti and Dunn’s technique, the synthesized SmMnO3/rGO NCs deliver the total (qTo′′), outer (qou′′), and inner qin′′ capacities of 490.19, 208.53, and 281.65 C/g respectively. The EIS analysis of SmMnO3/rGO NCs delivers low Rs (Solution resistance) and Rct (Charge-transfer resistance) of 0.26 Ω and 0.06 Ω. Moreover, the hybrid supercapacitor (SmMnO3/rGO//AC) device (HSC) was fabricated and tested for electrochemical performances which delivered excellent specific capacity (Cspecific4) of 205.71 C/g at 0.5 A/g current density, superior energy density (Edevice) of 48.28 Wh/kg, and the power density (Pdevice) of 422.49 W/kg at 0.5 A/g current density, and possesses better capacitive retention of 49.63% and the coulombic efficiency of 100.12% over 6000 charge-discharge cycles.