Charge-discharge Profiles Research Articles

Performance of full-cell Na-ion with NaNi1/3Mn1/3Co1/3O2 cathode material and different carbonate-based electrolytes

The battery performance not only depend on the electrodes nature but also depend on the choice of electrolyte consisting of salts and organic solvents. The development of electrolytes compatible with both cathode and anode materials is essential for enhancing the performance of practical full-cell Na-ion batteries. Among electrode with difference Ni/Mn/Co ratio, NaNi1/3Mn1/3Co1/3O2 (NMC) showed the best stable cycling. Besides, carbonaceous anode materials such as hard carbon (HC) are attracting due to it low cost, high gravity/volumetric capacity. In this work, the electrochemical performance of full-cell Na-ion including NMC as cathode and HC as anode was studied in difference carbonate-based electrolytes with 2wt%FEC as additive. The cathode material was synthesized by sol-gel reaction following a calcination at 900oC for 12 hours. X-ray diffraction result of the synthesized sample indicates a layered structure with mutual O3 and P2 phase intergrowth and the dominant phase is O3. The impurity phase NiO also presents with negligeable content. In half-cell configuration with sodium metal anode, the material exhibited a typical staircase chargedischarge profile in various electrolytes. The highest capacity of 106 mAh/g with stable clycing up to 50 cycles was obtained in the electrolyte NaClO4 1 M/PC+2wt%FEC. However, this electrolyte couldn't enable the cycling the full-cell HC||NMC due to the incompatibility with HC anode. In consequence, the initial capacity of full-cell in this electrolyte was only 30 mAh/g and significantly decreased in consecutive cycles. Meanwhile, the electrolytes without PC or with low PC content tend to improve the charge/discharge capacity and the cycle life as well. Indeed, full-cell HC||NMC using NaClO4 1M/EC-DMC (1:1) + 2wt%FEC electrolyte exhibited the highest capacity of 90 mAh/g and excellent capacity retention (90% of the initial capacity) after 50 cycles. Additionally, the full-cell could deliver capacity of 55 mAh/g at high rate up to 2C.

A new multi-task learning framework for fuel cell model outputs in high-dimensional spaces

In this paper we develop a multi-output, multi-task framework for approximating the outputs of complex physics-based computer models of fuel cells and batteries. For applications that require real-time or a high number of runs, such as optimization and control, the original computer model will be impractical, making such approximations necessary. It is normally the case that there are several quantities of interest (different tasks) from the model, such as the potential, reactant distributions and the cell voltage charge–discharge profile. We overcome several challenges in this paper: dealing with very high dimensional outputs (e.g., a distribution defined at many grid points), accounting for correlations between tasks, and accounting for noise in the outputs or missing information. We combine a multivariate Gaussian process (GP) model based on dimension reduction with a linear model of coregionalisation (LMC) to account for the between-task covariances. The LMC applies to coefficients in a low-dimensional subspace (each coefficient corresponding to a particular task), which results in highly-efficient training. We test the framework on two different 3-d hydrogen fuel cell models and compare the results to several alternative multivariate GP approaches. The results reveal that our framework is more accurate and also more computationally efficient.

Plasticized H+ ion-conducting PVA:CS-based polymer blend electrolytes for energy storage EDLC application

In this work, plasticized proton-conducting polymer blend electrolytes based on poly (vinyl alcohol): chitosan were synthesized, characterized, and utilized in an electric double-layer capacitor (EDLC). A structural study was performed using X-ray diffraction. The scarification and decrease of intensity of the crystalline peak were detected upon the addition of glycerol plasticizer (GP). The morphological appearance of the plasticized blend electrolyte films was examined through scanning electron microscopy, in which the role of GP on ion dissociation was indicated to be important. Electrochemical impedance spectroscopy was performed to estimate the conductivity of the films. Before the EDLC application, other electrochemical techniques, such as transference number measurement (TNM), linear sweep voltammetry (LSV), and cyclic voltammetry (CV), were carried out. To evaluate the performance of the EDLC, the charge–discharge profile was then examined. The EDLC has been cycled 250 times at a current density of 0.75 mA cm−2. The specific capacitance (Cspe) of the EDLC, which is known as an essential parameter, was found to be constant after the first cycle. The reduction in Cspe value was correlated with the increase of equivalent series resistance. Finally, the manners of energy (E) and power (P) densities as a function of the number of cycles were studied.

3D copper-confined N-Doped graphene/carbon nanotubes network as high-performing lithium-ion battery anode

A facile synthesis of three-dimensional (3D) network of copper confined nitrogen-doped graphene (NG)/carbon nanotube (CNT) with high atomic percentage of nitrogen (10.1 at.%) has been reported. The homogenous intercalation of the CNT network in-between the graphene layers decorated with copper nanoparticles take place which inhibits the self-agglomeration within the lattice and enhance the volumetric storage capability. The composite electrode demonstrates exceptionally high specific capacitance of 1250 mA h/g obtained at a current density of 0.1 A/g which is 3.4 times greater than the theoretical capacity of graphite (372 mA h/g). The discharge-charge profiles (from 0.002 to 3 V) with reversible battery capacity exhibit a stable state of the lithium-ion batteries which were observed at high rate capability of 420 mA h/g at a current density of 1 A/g even after 500 cycles. The enhancement of the electrochemical performance could be attributed to the 3D electrically conductive networks of copper confined nitrogen-doped graphene/carbon nanotubes (Cu@[N-Gr/CNT]).

Hydrothermal synthesis and characterization of nanostructured nickel diselenide (NiSe2) from the decomposition of nickel acetate tetrahydrate (Ni(CH3COO)2).4H2O

Nickel diselenide (NiSe2) had been conflated from the reaction of nickel acetate tetra hydrate (C4H14NiO8) with selenium (Se) powder by simple hydrothermal method at 200 °C for 5 hrs. The structural analysis revealed that the synthesized samples are consists of cubic structure. The electrochemical performance was obtained from the cyclic voltammetery (CV) and galvanostatic charge discharge (GCD) profiles. The prepared NiSe2 exhibited the specific capacitance value of 384 Fg−1 at scan rate of 2 mVs−1. The obtained results ensure that the NiSe2 nanoparticles could act as an enhanced working electrode for the upcoming generation of supercapacitors.

Metal Complex as a Novel Approach to Enhance the Amorphous Phase and Improve the EDLC Performance of Plasticized Proton Conducting Chitosan-Based Polymer Electrolyte.

This work indicates that glycerolized chitosan-NH4F polymer electrolytes incorporated with zinc metal complexes are crucial for EDLC application. The ionic conductivity of the plasticized system was improved drastically from 9.52 × 10−4 S/cm to 1.71 × 10−3 S/cm with the addition of a zinc metal complex. The XRD results demonstrated that the amorphous phase was enhanced for the system containing the zinc metal complex. The transference number of ions (tion) and electrons (te) were measured for two of the highest conducting electrolyte systems. It confirmed that the ions were the dominant charge carriers in both systems as tion values for CSNHG4 and CSNHG5 electrolytes were 0.976 and 0.966, respectively. From the examination of LSV, zinc improved the electrolyte electrochemical stability to 2.25 V. The achieved specific capacitance from the CV plot reveals the role of the metal complex on storage properties. The charge–discharge profile was obtained for the system incorporated with the metal complex. The obtained specific capacitance ranged from 69.7 to 77.6 F/g. The energy and power densities became stable from 7.8 to 8.5 Wh/kg and 1041.7 to 248.2 W/kg, respectively, as the EDLC finalized the cycles.

NiF2 as an efficient electrode material with high window potential of 1.8 V for high energy and power density asymmetric supercapacitor

We investigated NiF 2 as an energy storage material in asymmetric supercapacitor together with activated carbon (AC) as the counter electrode. Cyclic voltammetry and galvanostatic charge-discharge profile are carried out to investigate the oxidation-reduction process and capacitive behavior of the NiF 2 sample. The interfacial electron transport properties of the sample are also explored using Nyquist plots in two and three electrodes configurations of electrochemical impedance spectroscopy. A very high specific capacitance of 751 F/g is achieved at 1 A/g current density in three electrode system. Further, the asymmetric supercapacitor device based on NiF 2 //AC structure reveals high capacitance of 175 F/g at 1 A/g in the high window potential of 1.8 V. The fabricated device retained 93% of its initial capacitance after 1000 cycles at 3 A/g current density affirms high electrochemical stability of the device. Ragone plot depicts high energy density of 79.65 Wh/kg with power density of 1727.35 W/kg for 1.8 V window potential at 1 A/g current density. High electrochemical stability of NiF 2 sample endures the tetragonal phase even after electrochemical measurement which can be more useful in recycling the electrode material for future recycled supercapacitor devices. • Pristine NiF 2 was employed for the fabrication of asymmetric supercapacitor device. • NiF 2 //AC device presented high C s of 175 F/g@1 A/g with high window potential of 1.8 V. • Ragone plot depicts high E D = 79.65 Wh/kg and P D = 1727.35 W/kg for 1.8 V@1A/g. • After electrochemical measurement, NiF 2 can be recyclable for further device fabrication.

Study on electrochemical properties of CMC-PVA doped NH4Br based solid polymer electrolytes system as application for EDLC

In the present work, solid polymer electrolytes (SPEs) based CMC-PVA blend doped with various contents of NH4Br were successfully prepared via solution-casting technique. The prepared samples were then characterized with respect to its thermal and conduction properties by using differential scanning calorimetry (DSC) and impedance spectroscopy. The highest dc conductivity at room temperature is observed to be 3.21 × 10−4 S cm−1 for a sample that consists of 20 wt.% NH4Br which demonstrated good thermal stability of Tg. The CMC-PVA doped NH4Br recorded an increment on the ionic conductivity with the increase in temperature, and thus obeys the Arrhenius behavior. The potential window for the highest conducting sample was found to be plateaued at 1.55 V. The performance of the EDLC fabricated with highest ionic conducting CMC-PVA doped NH4Br was also examined through cyclic voltammetry (CV) and it was shown that the specific capacitance increased as the scan rate reduced. Based on the charge-discharge profile, it is apparent that the proposed system has excellent cyclic retention as it is able to keep the performance of the EDLC at ~88% even after 1000 cycles.

Utilizing 2D Graphite Carbon Nitride for Industrial Applications – from Supercapacitors to Biosensors

2D materials are slowly overcoming the critical drawbacks of stability, low conductivity, reproducibility and cost. Therefore, with their intrinsic advantages of: ultra-large specific surface areas, well-defined layered architecture, tuneable redox activity and material hybridization, many 2D materials beyond graphene are being discovered. Few such 2-D materials, which have been reported are WS2, MoS2, h-BN, etc. Recently, 2D nano-sized graphite carbon nitride (g-C3N4) has been reported, with prediction that it can become an excellent candidate for miniaturized energy storage and optoelectronic devices. Graphite carbon nitride is a 2-D layered structure, where the tris-triazine unit are connected with planner amino groups in each layer, and weak van der Waal force acts between the layers. The quantum size effect are quite prominent along the inplane direction, which leads to interesting modulations in electrical and chemical properties. The nitrogen functional groups-rich frame-work is also expected to synergistically contribute in enhancing the electrochemical response of the material. Large synthesis of this material has remained a challenging task.In this paper, using a low-cost pyrolysis synthesis protocol, it is established that 2D nano-sized graphite carbon nitride can be produced in large quantities, with reproducible characteristics. The preliminary characterization of graphite carbon nitride was performed using XRD, SEM, TEM, Raman, FTIR, AFM, and BET techniques. The sizes of the nanosheets was found to be in the range of 200-300 nm, while the thickness of these sheets was ~90 nm. The performance of 2D nano-sized graphite carbon nitride in supercapacitors was investigated in detail. The electrochemical properties were investigated by cyclic voltammetry and charge-discharge measurements in 3 M KOH. The results clearly indicated improved cyclic stabilities up to 2500 cycles, with a specific capacitance of 84 F g-1 at 1 A g-1 current density. A typical charge-discharge profile (as a function of current density) for the synthesized g-C3N4 is shown in Fig. 1. A symmetric supercapacitor was also fabricated using this material as an active electrode, which showed ~ 11Wh Kg-1 energy and 500 W Kg-1 power density. The versatilaty of the material is established by extending its application to biosensing and catalytic applications. The results of electrochemical sensor for the detection of hydrogen peroxide is also presented in the paper. The result of cyclic voltammetry and chronoamperometric experiments showed that the linear response ranges are 0-80 nM, with a detection limit of 0.42 nM. The materials also shows excellent capability to catalytically reduce p-nitrophenol, which is a common pollutant in industrial waste water. Figure 1

Evaluation of PBI Nanofiber Membranes as a High-temperature Resistance Separator for Lithium-ion Batteries

Separators with excellent thermal stability and electrolyte wettability are essential for high-energy-density lithiumion batteries (LIBs). In this study, polybenzimidazole (PBI) nanofiber membranes were prepared by electrospinning and subsequent thermal calendering for a high-temperature resistance and flame-retardant LIB separator. The PBI nanofiber membrane calendered at 120 oC (PBI-120) was evaluated as an LIB separator due to its overall good physical properties. PBI- 120 showed better thermal dimensional stability, electrochemical stability, ionic conductivity, and interfacial compatibility with the electrodes than did a commercial separator, Celgard 2400. The cell assembled with PBI-120 showed stable chargedischarge profiles and cycle performance. The PBI nanofiber separator was demonstrated to be a promising separator candidate for enhanced safety and electrical performance of high-energy-density LIBs.

A Superlattice-Stabilized Layered Oxide Cathode for Sodium-Ion Batteries.

Sodium-ion batteries are in high demand for large-scale energy storage applications. Although it is the most prevalent cathode, layered oxide is associated with significant undesirable characteristics, such as multiple plateaus in the charge-discharge profiles, and cation migration during repeated cycling of Na-ions insertion and extraction, which results in sluggish kinetics, capacity loss, and structural deterioration. Here, a new strategy, i.e., the manipulation of transition-metal ordering in layered oxides, is proposed to show a prolonged charge-discharge plateau and cation-migration-free structural evolution. The results demonstrate that the transition-metal ordering with a honeycomb-type superlattice can adjust the crystal lattice and suppress cation migration by modifying the crystal strain to realize a large reversible capacity and excellent cycling performance, which are not characteristics of the widely used common layered oxides. These findings can provide new insight that can be used to improve the design of high-performance electrode materials for secondary-ion batteries.

New composite Li1.4Mn0.61Ni0.18Co0.18Al0.03O2.4 and LiNi0.5Mn1.5O3.9F0.1 cathode material with higher specific capacity and better capacity retention

Aluminum-modified Li1.4Mn0.61Ni0.18Co0.18Al0.03O2.4 (LNCMA) and fluorine-modified LiNi0.5Mn1.5O3.9F0.1 (LNMOF) cathode materials were successfully synthesized via a solid-state reaction procedure. The discharge capacity of the LNCMA increased from 175.3 to 192.2 mAh g−1, showing approximately a 9.6% improvement after 50 cycles due to Al doping. For the LNMOF cathode, the discharge capacity increased from 116.9 to 174.9 mAh g−1 after F doping, corresponding to an increase of 49.6% after 50 cycles. The new composite cathode was formed by mixing the two cathode materials at a weight ratio of 1:1, which was selected based on the charge–discharge profiles during the first cycle. When the cells were tested in a voltage range of 2.0–4.85 V, the composite material exhibited initial specific capacities of 229.2 and 215.4 mAh g−1, a coulombic efficiency of 94.0% during the first cycle, and a capacity retention of 94.5% after 50 cycles at 0.2C. The concept of inserting irreversible Li ions from the Li-rich material into the 16c vacancy of the LNMOF was validated. The improved capacity was due to the plateau in the discharge capacity curves due to the Mn3+ → Mn2+ reduction. The charge–discharge capacities of the composite material were higher than those in the literature, as was the coulombic efficiency. The new composite material inherited a high-voltage plateau from the LNMOF and a high specific capacity from the LNCMA, and this material has great potential for future applications.

Optimal location identification for aggregated charging of electric vehicles in solar photovoltaic powered microgrids with reduced distribution losses

ABSTRACT The battery-powered electric vehicle finds an alternative for fossil fuel-based vehicles in the transportation sector. The charge-discharge power profiles of the battery storage systems (BSS) contribute toward distribution losses, which can be minimized by proper scheduling. Such scheduling gives better results if the charging stations are optimally placed in the solar photovoltaic (PV) powered microgrid. This paper proposes a methodology to identify the optimal location to charge the electric vehicle in the microgrid. The proposed methodology has been developed using particle swarm optimization (PSO)-based optimal power flow (OPF) with an integrated power management (IPM) algorithm. The novelty of the IPM algorithm is the coordinated charging-discharging of the multiple numbers of aBSS of the EVs to reduce the overall distribution losses of the microgrid. The proposed methodology is tested in a standard solar PV powered microgrid network, where the optimal locations to charge the electric vehicles are identified. The daily distribution loss of the network is computed for all possible charging locations of the electric vehicle in the microgrid, and it is found that the distribution loss is minimum for the identified optimal locations. Also, to evaluate the effectiveness of the proposed methodology, the distribution loss analysis is carried out for three test cases; i) un-optimized power flow, ii) PSO based-OPF, and iii) PSO-based OPF with IPM. The case study shows that the PSO-based OPF gives 84% reduction in daily distribution loss compared to the conventional un-optimized power flow test case. The daily distribution loss is further reduced by 8% by incorporating the IPM algorithm in the PSO-based OPF. The utility can thereby encourage the electric vehicle (EV) owners to park their EVs at the optimal locations to reduce the distribution losses.

Iron-Based Mixed Phosphate Na4Fe3(PO4)2P2O7 Thin Films for Sodium-Ion Microbatteries.

Iron-based polyanionic materials can be exploited to realize low cost, durable, and safe cathodes for both bulk and thin film sodium-ion batteries. Herein, we report pulsed laser deposited mixed phosphate Na4Fe3(PO4)2P2O7 as a positive electrode for thin film sodium-ion microbatteries. The bulk material and thin films of Na4Fe3(PO4)2P2O7 are employed by solution combustion synthesis (SCS) and the pulsed laser deposition (PLD) technique, respectively. Phase purity and the nature of the crystallinity of the thin films were confirmed by grazing incidence X-ray diffraction and transmission electron microscopy. Identification of surface roughness and morphology was obtained from atomic force microscopy and scanning electron microscopy, respectively. Emerging electrochemical properties were observed from charge–discharge profiles of the thin films, which are well comparable to bulk material properties. The Na4Fe3(PO4)2P2O7 thin film electrodes delivered a highly reversible Na+ storage capacity of ∼120 mAh g–1 with an excellent stability of over 500 cycles. Electrochemical analysis results revealed that the thickness of the film affects the storage capacity.

Supercapacitor like behavior in nano-sized, amorphous mixed poly-anion cathode materials for high power density lithium and other alkali-metal ion batteries

In this manuscript, we report a new mixed poly-anionic framework based material as a cathode for lithium-ion batteries which is having an amorphous structure as compared to traditional crystalline nature of cathode materials, with a chemical formula of Na2Fe(PO4) (CO3). The amorphous mixed poly-anion cathode is synthesized using one-pot microwave hydrothermal synthesis technique, which is a faster and cheaper technique as compared to the traditional techniques of forming amorphous structures. The particle size of the material lies in the nano-regime, with a particle size distribution in the range of 10–80 nm. The amorphous structure, combined with the small particle size, shows excellent electrochemical properties as lithium-ion battery cathode. The half-cells are able to charge at constant specific current of 1 A g-1 (∼10C rate), and deliver an energy density of ∼150Whkg−1 at a specific discharge current of 50 mAg−1, consistently without fading. The cell is able to charge to ∼85% of its theoretical capacity in under 7 min with CC-CV charging scheme, and deliver the capacity at 50 mAg−1 specific discharge current (∼0.5C) with an efficiency >97% for ∼150 cycles, with ∼100% capacity retention. The high energy density and the anomalous charge-discharge profile of the material make it extremely suitable for next-generation supercapacitors as well.

Highly Active Electrode With Efficiently Added Surface Oxygen Groups for a Vanadium Redox Flow Battery

AbstractHigher power output by a lower kinetic resistance of the vanadium redox flow battery is needed for its commercialization. In this study, we focused on the air oxidation conditions of carbon paper, which is the electrode material, to reduce the kinetic resistance. The air oxidation is considered to affect the number of surface oxygen groups such as the phenol-type hydroxyl group due to oxidation of the carbon fiber. The surface oxygen groups may correspond to the active sites for the charge/discharge reaction. We quantitatively evaluated the number of surface oxygen groups by temperature-programmed desorption. In addition, we measured the double-layer capacitances of the carbon papers, which may reflect the surface area of the carbon fiber. The single-cell performances, i.e., current–voltage curves and charge–discharge profile, of the electrodes were studied. The air oxidized carbon paper, heat-treated at 500 °C for 3 h (8.4% mass decrease from the pristine sample), showed the highest power density (960 mW cm−2) in this study with thin electrode material (ca., 0.2 mm for one sheet). The negative half-reaction was enhanced by air oxidation. This result could be explained by the reduction of the kinetic resistance by increasing the number of phenol groups, and this power output was relatively high as the vanadium redox flow battery by using a commercial carbon paper and the standard flow field.

Promoting Transport Kinetics in Li-Ion Battery with Aligned Porous Electrode Architectures.

Developing scalable energy storage systems with high energy and power densities is essential to meeting the ever-growing portable electronics and electric vehicle markets, which calls for development of thick electrode designs to improve the active material loading and greatly enhance the overall energy density. However, rate capabilities in lithium-ion batteries usually fall off rapidly with increasing electrode thickness due to hindered ionic transport kinetics, which is especially the issue for conversion-based electroactive materials. To alleviate the transport constrains, rational design of three-dimensional porous electrodes with aligned channels is critically needed. Herein, magnetite (Fe3O4) with high theoretical capacity is employed as a model material, and with the assistance of micrometer-sized graphine oxide (GO) sheets, aligned Fe3O4/GO (AGF) electrodes with well-defined ionic transport channels are formed through a facile ice-templating method. The as-fabricated AGF electrodes exhibit excellent rate capacity compared with conventional slurry-casted electrodes with an areal capacity of ∼3.6 mAh·cm-2 under 10 mA·cm-2. Furthermore, clear evidence provided by galvanostatic charge-discharge profiles, cyclic voltammetry, and symmetric cell electrochemical impedance spectroscopy confirms the facile ionic transport kinetics in this proposed design.

Implication of charge transfer property on the supercapacitive performance of manganese oxide originated through different synthesis routes

In the present investigation manganese oxide in three different forms; Mn-Oxide/pristine, Mn-Oxide/rGO-1 (synthesised through hydrothermal route in HCl media) and Mn-Oxide/rGO-2 (synthesised through hydrothermal route in ethylene glycol) were synthesised. Materials were characterised using spectroscopic, structural and morphological investigation. Supercapacitance property of the materials was investigated through various electrochemical techniques. Materials were having similar structural behaviour, however their morphological characteristics were different. Most superior supercapacitance property was observed in case of Mn-oxide/rGO-2 composite material. Stable charge discharge profile was observed in all the materials when recorded up to 2000 cycles. The specific capacitance values in the case of Mn-Oxide/pristine, Mn-Oxide/rGO-1 and Mn-Oxide/rGO-2 were obtained as 200, 400 and 750 Fg−1 respectively.

Solution processed Copper Phthalocyanine nanowires: A promising supercapacitor anode material

Abstract In this paper, Copper Phthalocyanine (CuPc) nanostructures are the focus of an electrochemical investigation. This Phthalocyanine is nitrogen enriched having metal redox centers that facilitate the redox reaction. CuPc nanowires are synthesized by a simple room temperature process from bulk CuPc powder and their electrochemical properties are explored for the first time. The as prepared samples are characterized by X-ray Diffraction, high resolution transmission electron microscopy, field emission scanning electron microscopy, etc. They are then tested electrochemically in a three electrode system. Cyclic voltammogram (CV) and charge discharge (CD) profiles have been recorded. The CuPc nanowire electrode exhibits 406 F/g capacitance at 5 mVS−1 scan rate and 260 F/g at 0.3 A/g current density. Long cycling stability up to 3000 cycles at 6 A/g has been carried out. The results show that this material can be used as the potential candidate for positive electrode in supercapacitor applications.

Fabrication of High Performance Asymmetric Energy Storage Device with WO3@Graphene By Electrochemical Exfoliation Method

The demand for batteries and supercapacitors on a single platform has been building up for decades now. The demand for supercapacitors stems from its peak power densities and long-term cycle life. However, transition metal oxides have high theoretical specific capacity to store charge but it drawbacks due to its low electronic conductivity and capacity fading with number of cycles. To overcome these usually metal oxides are embedded with the conductive matrix. The conductive matrix like graphene not only provides path for easy electron movement it also increases the surface area for higher interaction of active electrode materials with electrolyte. Hence it attracts active research pursuits in synthesizing low cost effective electrode materials. In this work, we report a facile and economic approach to produce tungsten oxidenanospheres embedded in graphene sheets (WO3@G) powders with an improved electrochemical activity.The method consists of exfoliation of graphite cardboard at constant voltage of 10 V in a metal sulphate bath. This ultimately yields black flakes like powders. The WO3@G powders' crystallinity was characterized by XRD which confirmed. The FE-SEM and TEM reveals the formation of nanospheres embedded on the graphene nanosheets. A comparison of the physical and chemical properties was intended with different concentrations of metal sulphate salt solutions. Interestingly, it was found that the yield of graphene also depends on the concentrations of salt bath. The Raman spectroscopy reveals the few exfoliated layers of graphene. We have examined the electrochemical activity of these different electrode materials by studying the supercapacitors properties like cyclic voltammetry, charge-discharge profiles and electrochemical impedance spectroscopy. Thus, we have reached a cheap and effective yield of promising candidate for the electrode materials for energy storage devices. The WO3@G positive electrode was assembled with graphene as negative electrode, sandwiched by gel-electrolyte. These prototype devices were capable of powering consumer electronics applications.