Electrode Materials For Capacitors Research Articles

Influence on effective and ineffective delamination of MXene (Ti3C2Tx) by tightly anchoring tin oxide nanocomposite for boosting the specific capacitance of supercapacitor

Rich surface functionalization properties and ion diffusion behavior make MXene a promising material for better self-discharge properties for Supercapacitor application. Utilizing a new electrode material for the renewable energy storage device is a very important factor for the environmental safety from the threatening fossil fuels. Herein, we report a highly capacitive and fast charge-discharge electrode material assembled by tightly anchoring SnO2 over Ti3C2Tx flakes (graphite sheet as a current collector) and the electrolyte Potassium Hydroxide (KOH) as a new promising material for supercapacitor electrode. XRD analysis with FESEM imaging showed that the tetragonal rutile structure of SnO2 nanoparticles was uniformly grown on the surface of sheet-like Ti3C2Tx. By optimizing Ti3C2Tx through delamination using TMAOH (Tetramethylammonium Hydroxide) and introducing SnO2 nanoparticles onto it by simple sonication, the developed electrode material delivered a maximum of specific capacitance (669 Fg−1 in the alkaline electrolyte) with stable cyclic performances (90% of retainability over Six thousand cycles) and shows a good rate performance. The comparison of delaminated and without delaminated samples reveals that the delaminated electrode can avoid the restacking of 2D MXene sheets and hence improve ion migration and electron transport in energy storage devices. This predominant performance demonstrated that Delaminated MXene/ SnO2 can effectively advance the future of electrode material for next-level supercapacitor applications.

Oaks-derived activated carbon by trace alkali-induced catalytic steam activation for electrochemical capacitor applications

With the aim of more efficiently using oaks resources, this study proposed a green and efficient strategy of trace KOH-induced catalytic activation to generate oaks-derived activated carbons (AC) for electrochemical capacitor applications. By studying the pore formation, trace KOH is found to be associated with mesopore formation and promotes the development of micropores in ACs, regulating the hierarchical structure of pores. Furthermore, trace KOH can enlarge the specific surface areas and change the surface functionalities of ACs. As the result, the obtained sample has a high specific surface area of 958 m2 g−1 and a total volume of 0.448 cm3 g−1. Evaluated as electrochemical capacitor (EC) electrode material, the obtained sample achieves a high specific capacitance of 157.5 F g−1 at a current density of 1 A g−1 and shows an excellent cycling performance with 97 % retention over 10,000 cycles at 2 A g−1. This work not only provides the mechanism understanding of the KOH-induced catalytic activation but also proves that the trace KOH-induced catalytic activation is a viable and green method for developing high-performance activated carbons for the demand of ECs in industrial applications.

Boosting Lithium Storage of a Metal-Organic Framework via Zinc Doping.

Lithium-ion batteries (LIBs) as a predominant power source are widely used in large-scale energy storage fields. For the next-generation energy storage LIBs, it is primary to seek the high capacity and long lifespan electrode materials. Nickel and purified terephthalic acid-based MOF (Ni-PTA) with a series amounts of zinc dopant (0, 20, 50%) are successfully synthesized in this work and evaluated as anode materials for lithium-ion batteries. Among them, the 20% atom fraction Zn-doped Ni-PTA (Zn0.2-Ni-PTA) exhibits a high specific capacity of 921.4 mA h g−1 and 739.6 mA h g−1 at different current densities of 100 and 500 mA g−1 after 100 cycles. The optimized electrochemical performance of Zn0.2-Ni-PTA can be attributed to its low charge transfer resistance and high lithium-ion diffusion rate resulting from expanded interplanar spacing after moderate Zn doping. Moreover, a full cell is fabricated based on the LiFePO4 cathode and as-prepared MOF. The Zn0.2-Ni-PTA shows a reversible specific capacity of 97.9 mA h g−1 with 86.1% capacity retention (0.5 C) after 100 cycles, demonstrating the superior electrochemical performance of Zn0.2-Ni-PTA anode as a promising candidate for practical lithium-ion batteries.

Potassium oxysalt-assistant strategy towards heteroatom-doped porous carbon electrodes for high-performance Na-ion capacitors

Heteroatom-doped porous carbons are regarded as one of the most promising electrode materials for Na-ion capacitors (NICs). However, it is still necessary to further explore low-cost and high-efficiency strategy for their preparation. Herein, two gelatin-derived carbons (GCs) are directly prepared by a potassium oxysalt-assistant strategy. K2SO4 and K3PO4 are employed as multifunctional auxiliaries (template, activator, and dopant) for the preparation of seaweed-like N,S-doped porous carbon (NSGC) and honeycomb-like N,P-doped porous carbon (NPGC), respectively. The NSGC and NPGC are employed as electrodes for NICs and their energy-storage behaviours are detailly investigated. Electrochemical tests combined with in-situ Raman and X-ray diffraction (XRD) measurements reveal that the rich heteroatoms/defects, rational carbon interlayer distance, and hierarchical porous structures of the GCs result in their superior electrode performance in half cells. A pouch NIC constructed with the NSGC anode and the NPGC cathode exhibits high energy density (143 Wh kg−1), high power density (9 kW kg−1), and long lifetime (80% capacity retention after 8000 cycles), showing the good prospect of the carbon electrodes for use in NICs.

Interface regulation for stabilizing phosphorous electrode with cyclically formed hetero-interfaces enables durable lithium-ion storage

Red phosphorus has attracted tremendous attention because of its high theoretical specific capacity, cost effective as well as environmental friendly characteristics. Nevertheless, its large volumetric expansion during the charge–discharge process and intrinsic poor conductivity have severely hindered the practical application of red phosphorus. A novel strategy of carbon-excluded in active materials to achieve performance improvement of red phosphorus is constructively explored by delicate interface regulations of building a dynamic hetero-interface on cycling. A very simple red phosphorus/sulfur (P/S) was prepared by moderately ball-milling process to achieve the purpose despite only two electron-insulating components of sulfur (S) and red phosphorus (P) are involved. The experiment results demonstrate that the in-situ formation of the temporary solid sheath of lithiated sulfur, which is partially incorporated in solid electrolyte interface (SEI) film around red phosphorus. It is the crucial factor to depress the decomposition of the electrolyte. Furthermore, theoretic calculations based on first-principles reveal that the built-in electric field in the transient interface of Li2S/P provides fast diffusion tunnels for ions and electrons, which facilitates to improve the kinetics of the electrode. Our research demonstrates the construction of dynamic hetero-interfaces have huge potentials to improve the sluggish kinetics of high capacity electrode materials.

N-doped porous carbon-based capacitive deionization electrode materials loaded with activated carbon fiber for water desalination applications

Capacitive deionization (CDI) is a kind of emerging desalination technology. The development of electrode materials with a high desalination rate and long life, which can be used in seawater/brine water desalination and the reduction of salty wastewater, is a research hotspot in the aspect of global water treatment. In this study, N-doped porous carbon was combined with activated carbon fibers by a green coating method to successfully prepared CDI electrode (NPC@ACF). The microstructure and electrode performance of NPC@ACF were characterized by different techniques. The specific surface area of NPC@ACF tested by BET was 1098 m2 g−1. The electrochemical performance of this material was studied, showing that the NPC@ACF electrode possesses a high specific capacitance of 268.90 F g−1. At the voltage of 1.2 V, the electrosorption capacity is 14.63 mg g−1, and the CDI desalination efficiency was increased by 39% and 63% compared with that of pure ACF or NPC, respectively. The NPC@ACF material has good recyclability showing a desalination efficiency retention rate of 27% after 50 cycles. With its recyclability, stability, and enhanced electrochemical characteristics, the NPC@ACF electrode has been proved to be an excellent electrode for CDI applications.

Facile fabrication of intercalation-type pseudocapacitive S-Ti3C2Tx/PANI/F-Ti3C2Tx cathode for asymmetric capacitive deionization

Although tremendous efforts have been paid on Ti3C2Tx as a cathode for capacitive deionization (CDI), its structural instability and easy agglomeration have always limited such a promising application. In this study, a hybrid of hollow Ti3C2Tx spheres and flakes was synchronously fabricated by a novel sacrificial-templated method for the first time, and then immobilized/bonded together by in-situ polymerization of polyaniline, which was labelled as S-Ti3C2Tx/PANI/F-Ti3C2Tx. The highest specific capacitance of S-Ti3C2Tx/PANI/F-Ti3C2Tx in 1 M NaCl solution was measured to be 102 F·g−1, and diffusion capacitance of the as-obtained S-Ti3C2Tx/PANI/F-Ti3C2Tx was calculated to be 63%. Thus, a high salt adsorption capacity of 76 mg·g−1 with a maximum salt adsorption rate of 11.45 mg·g−1·min−1 was obtained, which is much higher than that of Ti3C2Tx-related materials in literature for asymmetric CDI system. Moreover, such a superior desalination performance was verified stable at almost 100% after 30 cycles. Besides the ion intercalation and fluoro/hydroxyl groups of Ti3C2Tx, the high performance and stability of the as-obtained S-Ti3C2Tx/PANI/F-Ti3C2Tx should also be ascribed to the beneficial effects of immobilization/bonding role of conductive PANI between S-Ti3C2Tx and F-Ti3C2Tx. This study gives a new perspective to promote the real applications of CDI by designing highly capacitive and stable electrode materials.

Hierarchical architecture of two-dimensional Ti3C2 nanosheets@Metal-Organic framework derivatives as anode for hybrid li-ion capacitors

Two-dimensional (2D) layered metal carbides materials called MXenes (e.g., Ti3C2) are significantly attentioned as electrode material for lithium-ion capacitors (LICs) because of its large surface-to-volume ratio and ultra-high electronic conductivity. Whereas, as anode electrode material, the performance and application prospects of Ti3C2 are severely restricted to its lower theoretical capacity. In this work, a straightforward and effective strategy to surmount the restrictions was developed to combine layered Ti3C2 nanosheets with dual Co/Zn metal–organic framework (MOF) polyhedrons derivatives through electrostatic assembly. Co3O4/ZnO polyhedrons could prevent the stacking of Ti3C2 nanosheets and provide prominent lithium storage capacity. Furthermore, the advanced structure of Ti3C2@Co3O4/ZnO as anode material could provide short Li+ paths, large electrolyte channels and excellent structural stability to enhance the electrochemical performance for LICs. As a result, the prepared Ti3C2@Co3O4/ZnO composite exhibited a specific capacity of 585.7 mAh/g at 0.1 A/g, and the electrode still delivered a capacity of 229 mAh/g at 2 A/g after 1000 cycles with 93% capacity retention in lithium-ion half cell. In addition, by assembling with activated carbon (AC) as cathode and Ti3C2@Co3O4/ZnO as anode, the LIC revealed an ultra-high energy density of 196.8 Wh/kg at a power density of 174.9 W/kg, and delivered a high energy output of 87.5 Wh/kg even at a power density of 3500 W/kg. And its capacitance retention reaches 75% after 6000 cycles at 2 A/g. The advanced structure, handy preparation, and outstanding performance of layered carbon-based material Ti3C2@hollow polyhedrons composite might provide promising applications in LICs.

Rational design of three-dimensional interlaced frameworks with 2D MXene-Ti3C2Tx and 2D ZnCo bimetallic hydroxide for enhanced sodium-ion capacitors

MXene-Ti3C2Tx is a promising material for next-generation energy storage for sodium-ion capacitors (SICs). However, the attraction between active functional groups and hydrogen bonds on the surface of Ti3C2Tx make the interlayer agglomerate obviously. Herein, we introduce 2D ZnCo bimetallic hydroxide (ZnCo-LDH) to adsorb on Ti3C2Tx nanosheets (Ti3C2Tx/ZnCo-LDH) and form the 3D interlaced porous frameworks, which could stabilize the complex structure and provide flexible ion diffusion channels. The ZnCo-LDH could not only increase the active sites for adsorbing the charges, but also prevent Ti3C2Tx from agglomerating and promote the electron transport kinetics. Benefited from this novel stable structure, Ti3C2Tx/ZnCo-LDH possess a wonderful specific capacitance (644.9 F g−1 at 2 mV s−1) and outstanding rate performance that combine with pseudocapacitance and low resistance. Particularly, the Ti3C2Tx/ZnCo-LDH electrode exhibit an excellent cyclic stability with 95.5% of the initial capacitance after 10000 cycles at 5 A g−1. More significantly, the SICs fabricated with 3D porous Ti3C2Tx/ZnCo-LDH display maximized energy density of 27.2 Wh kg−1 and power density of 7987.5 W kg−1, and an outstanding cycle stability of 95.8% after 10000 cycles. This work could provide an effective strategy for the preparation of MXene and LDH composites as electrode materials for sodium ion capacitors.

Synthesis and Characterization of Rgo Doped Nb2O5 Nano Composite for Chemical Sensor Studies

It has been reported that an effective synthesis of rGO-Nb2O5 composite for electrochemical sensor studies has been reported. The modified Hummer's method was used to produce reduced graphene oxide (rGO). The metal oxide (Nb2O5) was introduced to the rGO via the hydrothermal method to form the composite. X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), and were used to examine the sample. The CV measurements show a significant improvement in electrochemical reversibility, with the specific capacitances of rGO and Nb2O5/rGO being 45 and 110 Fg-1, respectively. These results indicate that the capacitive behavior and electron transfer of the Nb2O5/rGO nano composite was significantly higher than that of rGO. The charge-discharge curves show good symmetry and linear deviations with time change, indicating superior capacitance. This is primarily due to the electrode reversible reaction, and it has also been revealed as a type of super capacitor electrode material. The electrode materials obtained have the highest specific capacitance and excellent rate capability.

Comparison of Pore Structures of Cellulose-Based Activated Carbon Fibers and Their Applications for Electrode Materials.

This study presents the first investigation of cellulose-based activated carbon fibers (RACFs) prepared as electrode materials for the electric double-layer capacitor (EDLC) in lieu of activated carbon, to determine its efficacy as a low-cost, environmentally friendly enhancement alternative to nanocarbon materials. The RACFs were prepared by steam activation and their textural properties were studied by Brunauer–Emmett–Teller and non-localized density functional theory equations with N2/77K adsorption isotherms. The crystallite structure of the RACFs was observed by X-ray diffraction. The RACFs were applied as an electrode material for an EDLC and compared with commercial activated carbon (YP-50F). The electrochemical performance of the EDLC was analyzed using galvanostatic charge/discharge curves, cyclic voltammetry, and electrochemical impedance spectroscopy. The results show that the texture properties of the activated carbon fibers were influenced by the activation time. Crucially, the specific surface area, total pore volume, and mesopore volume ratio of the RACF with a 70-min activation time (RACF-70) were 2150 m2/g, 1.03 cm3/g and 31.1%, respectively. Further, electrochemical performance analysis found that the specific capacitance of RACF-70 increased from 82.6 to 103.6 F/g (at 2 mA/cm2). The overall high specific capacitance and low resistance of the RACFs were probably influenced by the pore structure that developed outstanding impedance properties. The results of this work demonstrate that RACFs have promising application value as performance enhancing EDLC electrode materials.

Heteroatom-doped reduced graphene oxide integrated with nickel-cobalt phosphide for high-performance asymmetric hybrid supercapacitors

The increasing energy demand and lack of sustainable energy storage systems have attracted considerable attention towards electrochemical capacitors. Transition metal phosphides have emerged as excellent electrode materials for electrochemical capacitors because of their highly metalloid characteristics and low cost. This paper reports the synthesis of binder-free nickel-cobalt phosphide nano horns wrapped with phosphorus-doped reduced graphene oxide by a hydrothermal reaction followed by phosphorization. The nickel-cobalt phosphide nano horns are formed by the Kirkendall effect due to differences in the diffusion rates of phosphorus ions and metal sources. The as-prepared electrode delivers a high specific capacity of 264.9 mAh g−1 (2384 F g−1) at 1 A g−1 and a high rate capability of 72 % at 15 A g−1. The asymmetric hybrid supercapacitor consisted of nickel-cobalt phosphide wrapped with phosphorus-doped reduced graphene as the anode, and activated carbon as the cathode yields a good energy density of 39.7 Wh kg−1 and a high power-density of 8.82 kW kg−1 with high cycling stability of 90 % after 10,000 charge–discharge cycles. The excellent pseudocapacitive properties of the as-prepared binary metal phosphide confirms its value for widespread practical applications in electrochemical supercapacitors.

Porous core-shell B-doped silicon–carbon composites as electrode materials for lithium ion capacitors

Development of anode materials of high capacities, rate capability, and cycling stability is critical for lithium ion capacitors (LICs). Composite electrode design, combining advantages of constituent component materials, is a promising approach for the purpose. Porous core-shell B-doped silicon-carbon spheres, B–Si@1RFC, of small sizes (150 nm) and high specific capacities are successfully synthesized with a one-pot method, followed by carbonization, magnesiothermic reduction, and B-doping, to be composited with reduced graphene oxide (rGO) porous structure of excellent structural and electrical properties to serve as an outstanding anode material, B–Si@1RFC/rGO, for LICs. The LIC, assembled by coupling the B–Si@1RFC/rGO anode with a glucose-derived carbon nanosphere cathode of ultrahigh specific surface areas (1947 cm2 g−1) and pore volumes (2.04 cm3 g−1), delivers a high energy density of 149 Wh kg−1 at a power density of 0.328 kW kg−1 and maintains a decent energy density of 82.1 kW kg−1 at a high power density of 49.3 kW kg−1, together with an excellent cycling stability of retaining 74.4% of the initial energy density after 10,000 cycle operations at 5 A g−1.

Effect of g-C3N4 amount on green synthesized GdFeO3/g-C3N4 nanocomposites as promising compounds for solid-state hydrogen storage

Hydrogen energy is a key role in novel renewable energy production/consumption technologies. Traditional hydrogen energy systems are suffered from low density, high production cost, low efficiency, and storage complications. With the start of solid-state hydrogen storage technology, many of above deficiencies are fulfilled, however, there are several unknown points, particularly in metal oxides, which need more attention. Hydrogen sorption on the layered materials or inside porous materials is a hopeful key to drawbacks for high-performance hydrogen sorption. Hereupon, layered solids with the merit of hydrogen sorption are introduced, for the first time, including “nanostructured bi-metal oxide (BMO)” and “graphitic carbon nitride (CN)”. Perovskites are ceramic and they are hard materials so they could be a favorable candidate for solid-state hydrogen storage. g-C3N4 has attractive features including high surface area, chemical stability, small band gap, and low-cost synthesis methods but also has great potential as an electrode material for energy storage capacitors. The main motivation for this study comes from the potential applications for perovskite materials and graphitic carbon nitride for the solid-state hydrogen storage method. The Perovskite type GdFeO3 nanostructures (as BMO) synthesized through sol-gel approach in front of natural source of Grape juice as both complexing agent and fuel. The experimental scrutinization ascertains an original fabrication of GdFeO3 (GF) nanostructures in Grape juice at 800 °C, with an approximately uniform nanosized structure of 70 nm on average. The obtained pure GF nanostructures are then utilized for nanocomposite formation based on g-C3N4 (CN) with different amounts. The resulting nanocomposites with the ratio of 1:2 from GF:CN perform a preferable hydrogen sorption capacity, in terms of “maximum discharge capacity of 577 mAhg−1” in 2 M KOH electrolyte. It should be declared that however, the discharge capacity of the nanostructured GF is 188 mAhg−1. It can be emphasized that these GF/CN nanocomposites can be utilized as hopeful hosts in an electrochemical hydrogen storage setup due to the synergic effect of g-C3N4 with essential characteristics in cooperation with BMO nanostructures as acceptable electrocatalysts.

A novel NiMn2O4@NiMn2S4 core-shell nanoflower@nanosheet as a high-performance electrode material for battery-type capacitors

This study reported a novel NiMn2O4@NiMn2S4 core-shell nanoflower@nanosheet synthesized via a simple two-step hydrothermal method as an excellent electrode material for battery-type capacitors. The NiMn2O4@NiMn2S4 was characterized by XRD, XPS, SEM and EDS. The "core" (NiMn2O4) and "shell" (NiMn2S4) are both active materials, and they both participate in the Faraday redox reaction to facilitate the NiMn2O4@NiMn2S4 electrode to obtain more excellent electrochemical characteristics. The specific capacity for the NiMn2O4@NiMn2S4 electrode reaches 803.08 C g−1 when the current density is 1 A g−1. Moreover, the specific capacity retention rate of the NiMn2O4@NiMn2S4 electrode reaches 91.5% after 5000 charge - discharge cycles when the current density is 20 A g−1. The energy density for the NiMn2O4@NiMn2S4//AC device reaches 73.65 Wh kg−1 at a power density of 775.04 W kg−1. Additionally, the NiMn2O4@NiMn2S4//AC demonstrates excellent self-discharge characteristics. Therefore, the NiMn2O4@NiMn2S4 electrode material presents extensive application prospects for battery-type capacitors.

Structural engineering for double-layer high-load LiFePO4 electrode with vertical imparity distribution of conductive additives

To improve the energy density of the batteries, constructing electrode structure should also be considered besides developing high specific capacity electrode materials. As the active material loading increases, the electrode rate performance worsens due to the long distance of electron transport and ion diffusion. This study proposes a simple and effective strategy to construct a high-load LiFePO4 electrode with excellent rate performance by using a double-layer structure. The bottom layer with more conductive additives forms a rich conductive network to improve the ability of electronic collection, the top layer with fewer conductive additives increases the porosity to facilitate ion diffusion. The capacity of the double-layer electrode (active material loading 11.4 mg cm−2) with imparity distribution of conductive additives achieves 98 mAh g−1 at 425 mA g−1 (2.5C). However, the capacity of the single-layer electrode is zero even at a lower loading (7.1 mg cm−2). The vertical imparity distribution of conductive additives in the double-layer structure can reduce the polarization and maintain the excellent rate performance of the high-load electrode. This strategy can be used not only in lithium-ion batteries but also for other energy storage systems possibly.

Reduced Graphene Oxide—Polycarbonate Electrodes on Different Supports for Symmetric Supercapacitors

Electrode materials for electrochemical capacitors or supercapacitors (SCs) are widely studied, as they are needed for the development of energy storage devices in electrical vehicles and flexible electronics. In the current work, a self-supported paper of reduced graphene oxide (rGO) with polycarbonate (PC) (as rGO-PC composite) was prepared by simple vacuum filtration and low-temperature annealing. rGO-PC as a freestanding single electrode was studied in a three-electrode system and presented a capacitive energy storage mechanism. To fabricate SCs based on rGO-PC, flexible polyethylene terephthalate (PET) with layers of both Cu tape (Cu tape) and carbon tape (C tape) (PET/Cu/C), as well as PET covered by graphene ink (PET/GrI), were used as supports. Fabricated flexible symmetric SCs have shown similar behavior with a higher areal capacitance value than that on PET/Cu/C substrate.

Activated carbon fiber–loaded single layer graphene oxide–based capacitive deionization electrode materials for water desalination applications

Activated carbon fiber–loaded single layer graphene oxide–based capacitive deionization electrode materials for water desalination applications

Bridged Carbon Fabric Membrane with Boosted Performance in AC Line-Filtering Capacitors.

High‐frequency responsive capacitors with lightweight, flexibility, and miniaturization are among the most vital circuit components because they can be readily incorporated into various portable devices to smooth out the ripples for circuits. Electrode materials no doubt are at the heart of such devices. Despite tremendous efforts and recent advances, the development of flexible and scalable high‐frequency responsive capacitor electrodes with superior performance remains a great challenge. Herein, a straightforward and technologically relevant method is reported to manufacture a carbon fabric membrane “glued” by nitrogen‐doped nanoporous carbons produced through a polyelectrolyte complexation‐induced phase separation strategy. The as‐obtained flexible carbon fabric bearing a unique hierarchical porous structure, and high conductivity as well as robust mechanical properties, serves as the free‐standing electrode materials of electrochemical capacitors. It delivers an ultrahigh specific areal capacitance of 2632 µF cm−2 at 120 Hz with an excellent alternating current line filtering performance, fairly higher than the state‐of‐the‐art commercial ones. Together, this system offers the potential electrode material to be scaled up for AC line‐filtering capacitors at industrial levels.

Investigations on partially exfoliated graphite as electrode material for electric double layer capacitors (EDLCs)

In this report, structural and electrochemical studies on exfoliated graphite (EG) as electrode material for electric double layer capacitor (EDLC) application are presented. The EG is obtained by activating the milled graphite powder using different wt.% of NaOH followed by thermal activation. The influence of activating agent NaOH on the structural, morphology and electrochemical performance of the EG has been investigated. The exfoliation inculcates more ordered graphitic structure and oxygen-functional groups, which play an important role in the porosity development in the EG. The activating agent NaOH reduces the crystallite size of EG from ∼ 16.50 nm to ∼ 16 nm on increasing its concentration (in wt.%) during activation process. A comparative study of the electric double layer capacitors (EDLCs) utilizing the electrodes of synthesized EGs and a liquid electrolyte of NaPF6 has also been demonstrated. The maximum specific capacitanceis obtained as ∼ 4.22F g−1 at 0.5 mA cm−2 current. The work suggests that the EG obtained by this low-cost synthesis method can be a suitable electrode material for EDLC.