Supercapacitive Behavior Research Articles

Supercapacitive performance of self-assembled thin film of liquid catocene/basal plane pyrolytic graphite electrode

Reasonable design of electrode material with low cost, lightweight, and excellent electrochemical properties is of great significance for future large-scale energy storage applications. Herein, we report the electrochemical and supercapacitive behaviour of the liquid redox of catocene, 2,2’-bis(ethyl-ferroceneyl) propane, self-assembled on a basal plane pyrolitic graphite electrode in comparison to the solid ferrocene thin film in aqueous sodium sulfate electrolyte. The modified electrode surfaces were evaluated to assess the iron content and the formation of thin film using scanning electron microscopy, laser-induced breakdown spectroscopy, and attenuated total reflectance method. Also, the supercapacitive performances of the related modified electrodes were assessed and compared using cyclic voltammetry and galvanostatic charge-discharge in a three-electrode system and an asymmetric two-electrode supercapacitor system. Electro­chemical results showed that the electrode processes are diffusion-controlled with battery-like behaviour, and the liquid catocene exhibits more effective interaction with the graphite surface in comparison to solid ferrocene. The catocene surface coverage on graphite is nearly 50-75 % higher than ferrocene, leading to improved interaction and charge transfer resistance, observed in electrochemical impedance spectroscopy studies. In galvanostatic charge-discharge evaluations, the supercapacitor based on catocene modified electrode shows a specific capacitance of 141.2 F g-1 at a current density of 1.0 A g-1, with a specific energy density of 56.7 Wh kg-1 at a power density of 2.9 kW kg-1.

Green Synthesis of ZnO Nanoparticles and Ag-Doped ZnO Nanocomposite Utilizing Sansevieria trifasciata for High-Performance Asymmetric Supercapacitors.

This study provides a comprehensive analysis of a biofabricated nanomaterial derived from Sansevieria trifasciata root extract, evaluating its structural, morphological, and optical properties for use in asymmetric supercapacitors. The nanomaterial comprises pristine ZnO nanoparticles (ZnO NPs) and a 1% Ag-doped ZnO nanocomposite (Ag@ZnO NC), synthesized through a green-assisted sol-gel autocombustion method. Employing techniques such as X-ray diffraction, ultraviolet-visible near-infrared, scanning electron microscopy-energy-dispersive X-rayspectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and transmission electron microscopy, the study confirms a hexagonal wurtzite structure and nanocrystallites with spherical and hexagonal shapes (30 nm). Optical analysis reveals a red shift in the band gap with Ag doping, indicating improved conductivity. The material shows potential applications in solar cells, optoelectronics, spintronics, wastewater treatment, and high-performance asymmetric supercapacitors. Raman spectra validate the wurtzite phase and identify intrinsic defects. Electrochemical tests demonstrate remarkable supercapacitive behavior with a 94% capacitance retention after 10,000 cycles, highlighting its promise as advanced asymmetric supercapacitors.

Electrochemical and structural performances of carbon and glass fiber-reinforced structural supercapacitor composite at elevated temperatures

The structural supercapacitor can store electrical energy and withstand structural loads while saving substantial weight in many structural applications. This study investigated the development of a structural supercapacitor with a fiber-reinforced polymer composite system and explored the operating temperature’s influence on its performance. The electrochemical and mechanical properties of structural supercapacitors beyond the ambient temperature have not yet been studied; hence, evaluating parameters such as specific capacitance, energy density, cycle life, and structural performance at elevated temperatures are highly desired. We have designed and manufactured single and parallelly connected multilayer structural supercapacitor composites in this research. Carbon fibers were used as a bifunctional component, acting both as a current collector while acting as a mechanical reinforcement. In addition, glass fibers were added as the separator which is also acting as an integral reinforcement. The electrochemical and mechanical behavior of structural supercapacitors at elevated temperatures up to 85 °C were experimentally investigated. The test results revealed that at room temperature, the developed double-cell structural supercapacitor, which demonstrated an area-specific capacitance of 1.16 mF cm−2 and energy density of 0.36 mWh cm−2 at 0.24 mA cm−2, which are comparable to current achievements in structural supercapacitor research. The structural supercapacitor’s tensile, flexural, and compression strengths were measured as 109.5 MPa, 47.0 MPa, and 50.4 MPa, respectively. The specific capacitance and energy density reached 2.58 mF cm−2 and 0.81 mWh cm−2, while tensile, flexural, and compression strengths were reduced to 70.9 MPa, 14.2 MPa, and 8.8 MPa, respectively, at 85 °C. These findings provide new comprehensive knowledge on structural supercapacitor devices suitable for applications operating within a temperature range from ambient conditions to 85 °C.

The electrochemical comparisons of reduced graphene oxide synthesized from pristine and recovered graphite from spent Li-ion batteries

Two reduced graphene oxides (rGO) were synthesized using two carbon sources, namely pristine graphite (rGO-PG), and recovered graphite (rGO-RG) (graphite recovered from spent Li-ion batteries) by modified hummers method and followed by the chemical reduction method to compare their supercapacitive performances. Their supercapacitance is found to be highly competitive and comparable with each other, except for their rate capabilities. The rate capability of rGO-RG is found to be inferior compared to rGO-PG. The supercapacitive behavior of both rGO’s was evaluated using five different aqueous electrolytes. The specific capacitance, specific energy, specific power, and columbic efficiencies exhibited by rGO-RG and rGO-PG were superior in the presence of 1 M H2SO4 and are 36 F g1, 7.1 Wh kg1, 0.88 kW kg1 and 96.55 %; and 40 F g1, 7.9 Wh kg1, 0.66 kW kg1 and 97.36 %, respectively. Both the rGOs exhibited no deterioration in their performance up to 10,000 continuous charge and discharge cycles at a current density of 10 A g1; rather, they exhibited enhancement in their performances with an increase in charge and discharge cycles. The enhancement exhibited by rGO-RG is superior to that of rGO-PG, which is 844 % (272 F g1) higher than its initial performance (29 F g1).

WITHDRAWN: Recent advances on the metal oxides and nanocomposites based on quantum dots and metal oxides for supercapacitor applications: A mini-review

Considering the limited resources of fossil fuels and the environmental pollution caused by their use, the need for alternative technology has become a global challenge. As a candidate for replacing fossil fuels, batteries have limitations such as the lack of sodium and lithium sources. Supercapacitors are a suitable alternative technology due to the availability of electrode materials. In this study, our team reviewed the supercapacitor performance of metal oxides and nanocomposites based on metal oxides and quantum dots to overcome the limitations of metal oxide electrode materials. In this study, by investigating the supercapacitor performance of nanocomposites based on metal oxide and quantum dots in three categories of carbon quantum dot, graphene quantum dot, and polymer dot, the performance of each quantum dot in improving the supercapacitor behavior of metal oxides was discussed. The results confirmed that the synergistic effect of quantum dots and metal oxides is improving the supercapacitor performance of nanocomposites. Also, the functional groups on the surface of the quantum dots accelerate the rate of penetration of ions and the rate of ion transfer. The results of this study confirmed that polymer dots have better performance among quantum dots with polymer properties and quantum dots properties at the same time which provides research opportunities for researchers in the field of supercapacitors.

Exploring the influence of Ni doping thin films for supercapacitor application

AbstractThis study explores the impact of nickel (Ni) doping bismuth ferrite (BiFeO3) thin film synthesis by spray pyrolysis method. The structural and morphological study shows that the thin films are slightly amorphous with granular morphology. Investigated the supercapacitive behavior of synthesized material by using cyclic voltammetry, galvanostatic charge‐discharge, and electrochemical impedance spectroscopy. The thin films synthesized are capable of storing a 253.31 F/g capacitance at a 10 mV/s scan rate and by introducing nickel into the synthesis process, we obtained 312.12 F/g capacitance at a 10 mV/s scan rate. The material shows good cyclic stability after 91000 cycles. It is also observed that no structural and morphological changes were made by doping Ni into BiFeO3 thin films. The significant improvement in capacitance was displayed by Ni doping into BiFeO3 obtained via spray pyrolysis methods indicating its potential for use in supercapacitor applications.

Ligand mediated self-assembly of cobalt nanoclusters for tunable supercapacitors

Self-assembly of thiolated cobalt-based nanoclusters was achieved by a simple and one-step synthesis process towards the development of a tunable hybrid supercapacitor. Here, we report the wet chemical synthesis of self-assembly of cobalt nanoclusters (CoNCs) using three different thiols namely glutathione (GS), 3-mercapto propyl sulfonate (MPS) and 3-mercapto propionic acid (MPA) protected individually. The variation in the capping ability of the thiolate ligands brings the proximal changes in the optical, structural and electrochemical properties. In CoNCs, the structural and morphological changes that evolved from the obtained GS-CoNCs, MPS-CoNCs, and MPA-CoNCs were confirmed using UV–vis spectroscopy, XRD, and TEM analysis. The stability of CoNCs and binding states of cobalt metal were determined using TG and XPS analysis respectively. The divergence in the rigidifying nature of various thiolated cobalt nanoclusters significantly influences their capacitance ability for energy storage via altering the porosity and electron transfer characteristics. The rigid dense multifunctional ligands like GS facilitate the electron-hole hopping process in the nano-pockets available in GS, which enhances the energy storage capability and diffusion among ligand-metal-ligand chains. Wherein, the other two ligands MPS and MPA show comparatively lower supercapacitance activities due to diverse functionality and rigidify. The charge-discharge studies explore the supercapacitor behaviour of GS, MPS and MPA-protected CoNCs with the specific capacitance of 540, 494 and 358 F g−1 respectively at the current density of 1 A g−1.

Effect of electrolytes on supercapacitive behavior of cubic shaped pristine cuprous oxide synthesized via sol-gel approach

The present study uses the sol-gel approach to employ cuprous oxide (Cu2O) as an electrode material for the electrochemical energy storage application. Scanning electron microscopy (SEM) examines the structural and surface morphological characteristics of the synthesized material, and pure phase development is verified by the X-ray Diffraction (XRD) patterns. The synthesized material has a high value of specific capacitance, notable porosity, and a well-defined cubic shape. In the three-electrode set-up, the electrochemical analysis uses different aqueous electrolytes, i.e., KOH and NaOH. The electrochemical outcomes indicate that the synthesized material has a maximum specific capacitance (Cs) of 362.77 Fg-1 with excellent stability (104 %) in 6 M NaOH than KOH electrolyte (225 Fg-1). EIS data for Cu2O-based electrodes have been modeled using various equivalent circuits. The ESR value of Cu2O in NaOH electrolyte is much smaller (0.503 Ω) than in KOH electrolyte, indicating the creation of more active sites and enhanced accessibility of ions. Capacitive and diffusion current contributions are shown by using the Trassati and Dunn techniques. Thus, all our findings suggest that sol-gel synthesized pristine cuprous oxide is a potential option for energy storage gadgets.

Poly(ethylene‐thiosuccinate)/carbon allotrope/cubic nickel‐cobalt hexacyanoferrate nanoparticles nanocomposites as supercapacitor materials

AbstractThis paper reports the synthesis of poly(ethylene‐thiosuccinate) (PETS) using succinic anhydride and 1,2‐ethanedithiol monomers and investigates its electrochemical behavior as supercapacitor electrode material. The synthesized polymer's structure is designed so that to contain sulfur atoms in the main chain of polymer, as the sulfur containing polymers are among the interesting active compounds for fabricating of novel devices for energy storage with wider voltage window and increase the energy density. The cyclic voltammetry (CV) graphs show the supercapacitor behavior of the materials with the faradic charge storage mechanism. The triangular shape of the charge–discharge curves indicate the reversible performance of the PETS as an electrode material. To enhance the supercapacitive action of PETS, its nanocomposites including PETS/Norit (1:1), PETS/MWCNT (1:1) and PTES/MWCNT (1:1)/(1.5%, 3% and 5%) Ni2CoHCF (nickel‐cobalt hexacyanoferrate) is prepared. The results indicate that the PETS/MWCNT/0.15% Ni2CoHCF nanocomposite exhibits a specific capacity which is 7 times higher than that of the PETS/MWCNT (1:1) nanocomposite, when the current density is 0.05 mA.cm−2. Also, according to the Nyquist diagrams, by incorporating of 1.5% of Ni2CoHCF in the PETS/MWCNT (1:1) nanocomposite, its electrical resistance decreases significantly by about two times.Highlights Poly(ethylene‐thiosuccinate) (PETS) made by succinic anhydride & ethanedithiol PETS/Norit or MWCNT/cubic Ni2CoHCF nanoparticles composites are prepared PETS/MWCNT composites as supercapacitor materials by Faradic storage mechanism PETS/1.5% Ni2CoHCF showed 0.0449 mF.cm−2 specific capacity at 0.01 mA.cm−2

Thiourea modulated supercapacitive behavior of reduced graphene oxide

In this report, we investigated the role of the concentration of nitrogen and sulfur containing thiourea in modulating the electrochemical properties of reduced Graphene Oxide (rGO) by controlling the percentage of heteroatoms on the rGO surface. The synthesis route involved the preparation of Graphene Oxide (GO) using an improved method of synthesis in an economical way by reducing the volume of concentrated acids used. Furthermore, GO is reduced by using different mass proportions of thiourea via a simple reflux method. Characterization of the rGO samples by Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDAX) and elemental analysis through CHNS analyzer exhibited successful doping and impact of nitrogen and sulfur atoms on the graphene framework. The comparative electrochemical performance from Cyclic Voltammograms (CV), Galvanostatic Charge Discharge (GCD) profiles and Electrochemical Impedance Spectroscopy (EIS) measurements on the various rGO samples revealed the superiority of 1:8rGO having 15.190 wt% of nitrogen and 26.849 wt% of sulfur and S/N ratio of 1.768, in delivering highest specific capacitance of 465.21 F·g−1 at 1 mV·s−1 scan rate with a remarkable cyclic stability exhibiting a capacitive retention of 119 % and offering lowest charge transfer resistance and diffusion resistance. The study also demonstrated detrimental effect of excess thiourea on electrochemical properties of rGO. This work suggests an effective and simple approach for optimizing the nitrogen and sulfur content in rGO to enhance its electronic properties using thiourea.

Comparative study of supercapacitive behaviour of vanadium oxide nanoflakes deposited hydrothermally on stainless steel mesh

Comparative study of supercapacitive behaviour of vanadium oxide nanoflakes deposited hydrothermally on stainless steel mesh

N-doped Bi2S3 nanoflower as an efficient supercapacitor electrode based on the highly concentrated salt electrolyte

As a low-cost and environmentally friendly new energy storage device, supercapacitors suffer from a low energy density, significantly restricting their potential applications. Hence, exploring supercapacitors with elevated energy density and wide potential windows has become a key research focus. Metal sulfides are receiving notable interest for their benefits, such as superb electrical conductivity, efficient charge storage, and cost-effectiveness. This study utilized ultrasonic methods to rapidly prepare Bi2S3 nanoflowers, followed by the synthesis of N-doped Bi2S3 through urea pyrolysis. And its supercapacitor behavior of N-doped Bi2S3 in 10 M NaNO3 electrolyte was studied. The assembled N–Bi2S3//N–Bi2S3 symmetric capacitor exhibited a high energy density of 112 Wh kg−1 when power density is 7828 W kg−1. The study provides a new scientific avenue for exploring the design of supercapacitors with high capacity and wide potential windows.

Crafting NaGd(MoO4)2 quadrilateral disks with oleic acid-assisted hydrothermal technique: Enhanced supercapacitor performance

Materials containing binary transition metals with MoO4 polyanions exhibit excellent stability, electrical storage capacity, long-term cycling resilience, and high operating voltage. In this study, an oleic acid-assisted hydrothermal synthesis method was used to control the morphology of NaGd(MoO4)2 quadrilateral disks (QuDs), and the electrodes based on the controlled morphology of NaGd(MoO4)2 QuDs were investigated for the fabrication of supercapacitors. In addition, cyclic voltammetry (CV) and constant current charge/discharge (GCD) analysis were performed to analyze the supercapacitance behavior of NaGd(MoO4)2 QuDs based electrode. The NaGd(MoO4)2 QuDs with 1.25 mL of oleic acid doped showed a good specific capacitance of ∼249.4 F∙g−1 at 0.01 V∙s−1 and excellent cycling stability, retaining up to ∼93.8% of its initial capacitance after 1000 cycles. Thus, the results indicate that the NaGd(MoO4)2 QuDs-based supercapacitor holds great potential as a high-performance option for advancing supercapacitor technology.

Structural, DFT and redox activity investigation of 2D silver based MOF for energy storage devices

A new silver(I) 2D MOF (Ag-MOF) was synthesized from 3,4-pyridinedicarboxylic acid (PDCA) by sonication method and characterized by single crystal X-ray diffraction, elemental analysis and FTIR spectroscopy. The material was further utilized for DFT computation and electrochemical performance. Theoretical and practicalresults for Ag-MOF geometrical parameters were found to be in reasonable agreement. Small HOMO-LUMO energy distance of 0.47 eV confirmed that electron transfer was much feasible. Distribution of electron isodensities was elaborated by DFT and FMOs computation. Double redox peaks in CV voltammograms reflected the change in oxidation state. Multiple plateaus in GCD curves showed the pseudo-capacitive behavior. Ag-MOF exhibited 101 Cg−1 specific capacity (Qs), 123 Wh.kg−1 energy density and 12,960 W kg−1 power density at current density of 5 Ag−1. There was a small difference in Rct and Ri which revealed that Ag-MOF had great ability to store energy. Presence of semi-circular arc in the EIS spectrum directly dictates the supercapacitor behavior. The electrode showed 97.5 % cyclic stability after 5000 cycles.

Zinc Cobalt Sulfide/Reduced Graphene Oxide Nanocomposite for High‐Performance Asymmetric Supercapacitor: A Microwave‐Assisted Synthesis

In this work, the microwave‐assisted synthesis of ZnxCo1–xS/reduced graphene oxide (rGO) nanocomposite and the evaluation of its electrochemical properties for supercapacitor (SC) application are dealt with. The synergistic effect between ZnxCo1–xS and rGO along with the conducting network provided by rGO facilitates the conducive movement of ions and enhances the electrochemical performance of the nanocomposite. The stoichiometric ratio of Zn:Co:rGO plays a crucial role in the SC behavior of the material. In three electrode systems, a material shows a high specific capacitance of 1094 F g−1 at current density 1 A g−1. The material stores charge both diffusively as well as capacitively. An asymmetric SC with acetylene black as the negative electrode and ZnxCo1–xS/rGO as the positive electrode has a stable potential window 0–1.6 V. For the fabrication of the electrodes, Ni foam is used as the current collector. The energy density and power density of the SC are found to be 32.71 and 431.95 W kg−1, respectively. The Coulombic efficiency of the SC is found to be 107% while its capacitance retention is 86% after 10 000 galvanostatic charge–discharge cycles. The energy and power density of the SC are comparatively higher than many recently reported literature. The material exhibits superior electrochemical stability and reversibility and can be a suitable electrode material for SCs.

Electrochemical Behaviour of Ultrasonic Probe Assisted Nickel Pyrophosphate (Ni2P2O7) Nanosheets for Supercapacitor Applications

New materials and synthesis strategies are needed to achieve better electrochemical performance. In this context, we developed a Ni2P2O7 Nanosheets (NNS) as a new classical-type active electrode using a simple and low-cost method. Crystal phase, chemical structure, and morphology of the sample were inspected by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Field Emission Scanning Electron Microscopy (FESEM) - Energy Dispersive Spectroscopy (EDS) analysis, respectively. As prepared electrode material was confirmed with monoclinic phase and nanosheet morphology identified from XRD and FESEM analysis, respectively. Various types of electrochemical approaches, such as CV, GCD, Cycling stability, and EIS applied in 2 M KOH electrolytes to investigate supercapacitive behaviour. As fabricated electrode material portrays satisfied specific capacitance (Cs) of 514.7F/g at a scan rate of 1 mV/s along with the excellent cyclic ability of 80 % retention upon 3000 continuous CV cycles, good rate capability in the extended potential window of 1 V. The GCD tests revealed remarkable specific capacity (462C/g) and exceptional energy density (64 Wh/Kg). Moreover, electrode material displayed impressive columbic efficiency as to be 77 % and 51 % at lower and higher current densities, respectively. These notable merits suggest that our designed Nanosheets (NNS) sample is the best opportunity for the development of sustainable supercapacitor devices.

Superior electrochemical performance of SnSe-PPy nanocomposites for supercapacitor application

Recently, Metal chalcogenides have received considerable interest in the field of energy storage devices. In this work, tin selenide-polypyrrole (SnSe-PPy) nanocomposite has been synthesized by hydrothermal method and its supercapacitive behavior is investigated. The synthesized SnSe-PPy nanocomposite is analyzed by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and electrochemical characterization. XRD confirms the existence of orthorhombic SnSe, and the FTIR result reveals the presence of polypyrrole. The supercapacitive behavior of SnSe-PPy nanocomposite is studied by cyclic voltammetry and galvanostatic charge-discharge studies. SnSe-PPy nanocomposite delivers the specific capacitance of 223 F g-1 at 10 mV sec -1. The addition of polypyrrole increases the conductivity of the material and improves its supercapacitive behavior.

Enhancing ASC Energy Storage: A Component-Based Modeling Approach

Among various electrical energy storage technologies like batteries and ultracapacitors, asymmetrical supercapacitors (ASC) stand out as hybrid devices combining battery-like as well as ultracapacitor-like characteristics. Despite extensive research with respect to this device, a significant research gap has emerged – the lack of investigation into the relationship between positive electrode parameters and the performance of ASC. The presented research work comprises a comprehensive study of ASC employing statistical modeling with the design of experiment (DoE) methodology. Component-based approach adopted, offers a more efficient and cost-effective way to predict the behavior and performance of asymmetrical supercapacitor over conventional electrochemical-based methods. It allows the creation of predictive models based on existing data, reducing the need for extensive experimentation without compromising on research output. It has established correlations between these parameters and two vital performance metrics: specific capacitance and pulse current. The outcomes of this study offer valuable insights into the positive electrode factors directly influencing specific capacitance and pulse current in manganese dioxide-activated carbon-based supercapacitors. This knowledge holds the potential to enhance the performance of ASC, making them promising candidates for replacing conventional battery-supercapacitor combinations in various applications.

IoT-based real-time monitoring of supercapacitors used in electric vehicles

The research focuses on the condition monitoring of supercapacitor systems installed in the electric vehicle that acts as the power source for the vehicle when it needs high power for a lesser time. This research work aims to introduce the Internet of Things in battery systems along with supercapacitors aiming to increase the efficiency and reliability of the system. In the corresponding research work, IoT-based condition monitoring for a 48V supercapacitor for an electric vehicle is implemented, the supercapacitor is charged using the phase shift full bridge DC-DC converter after that the data is transferred from the Matlab Simulink to the Thingspeak platform to enable IoT based application Hence establishing the real-time monitoring of super- capacitor. Introducing the Internet of Things will help researchers in a deeper understanding of supercapacitor behavior in a real-time environment as well as the real-time data will be helpful in the protection of the system.

Optimization of the Porous Structure of Carbon Electrodes for Hybrid Supercapacitors with a Redox Electrolyte Based on Potassium Bromide

This work investigates the electrochemical behavior of hybrid supercapacitors with carbon-based electrodes of different porosity using 5M NaNO3 + 0.5M KBr electrolyte to optimize energy storage processes. Three types of carbon materials were synthesized: activated carbon from rice husk (RH) with a specific surface area of ~2300 m2/g and pore size < 1 nm, and templated carbons from magnesium citrate (MP-8) and glucose with SiO2 as a template (G7), having surface areas of 1976 and 1320 m2/g and pore sizes of 3.4 and 7 nm, respectively. The microporous structure of activated carbon (AC) obtained from RH shows limitations in the diffusion of electrolyte ions, which affects the charge-discharge kinetics. In contrast, the larger mesoporous structures of templated carbons promoted better adsorption and ion transport, significantly affecting the dynamics of redox reactions. The RH/MP-8 hybrid capacitor, combining high surface area and large pore size, demonstrated a 54% increase in specific capacitance, 128% increase in specific energy and 51% increase in energy efficiency at high current densities of 5 A/g, comparing to the symmetric RH/RH hybrid capacitor. This study highlights the critical importance of the relationship between electrode pore structure and electrolyte composition for optimizing supercapacitor performance, which provides valuable information for the development of efficient energy storage technologies.