Electrode Materials For Supercapacitors Research Articles

Microporous tungsten oxide spheres coupled with Ti3C2Txnanosheets for high-volumetric capacitance supercapacitors.

In the contemporary landscape of technological advancements, the burgeoning demand for portable electronics and flexible wearable devices has necessitated the development of energy storage systems with superior volumetric performance. Tungsten oxide (WO3), known for its high density and theoretical capacitance, is a promising electrode material for supercapacitors. However, low conductivity and poor cycling stability are still the key bottlenecks for its application. Herein, a novel composite comprising hollow porous WO3 spheres (HPWS) derived by template method was electrostatic self-assembled on the surface of the Ti3C2Tx nanosheets. The resulting electrodes exhibited ultra-high volumetric capacitance of 1930 F cm-3 at 1 A g-1 and rate capability of 46% at 50 A g-1, attributed to enhanced ion accessibility from microporous structure and electron transport from conductive network of Ti3C2Tx even at a high packing density of 3.86 g cm-3. Utilizing HPWS/Ti3C2Tx as the negative electrode and porous carbon as the positive electrode, the assembled asymmetric supercapacitor achieved an energy density of 31 Wh kg-1 at a power density of 650 W kg-1 with over 107% capacitance retention after 5000 cycles. This work provides a promising approach for developing next-generation supercapacitors with ultra-high volumetric capacitance.

Synthesis and application of nanorod Bi2WO6/ZnO/rGO composite as a latent high-performance supercapacitor electrode

Bismuth Tungstate/Zinc oxide/reduced Graphene Oxide (Bi2WO6(BWO)/ZnO/rGO) nanocomposites with various ratios of rGO were fabricated utilizing a surfactant-driven hydrothermal process to investigate structural, morphological, and electrochemical properties as a potential electrode material. Compared with the BWO/ZnO/rGO(0.03 wt%) to BWO/ZnO/rGO(0.02 wt%) and BWO/ZnO/rGO(0.02 wt%) composite electrodes, the composite with the highest concentration of rGO with a particular capacitance demonstrates much greater capacitive performances(Cs) of 254.34 Fg−1 at 2 A/g with high cycling stability with capacitance retention of 79.67 % of the initial capacitance(Cs). A good rate capacity of 87.39 % at 5 A/g, 85.37 % at 10 A/g, and a 79.67 % reduction of its initial capacitance at an extreme charge/discharge current density of 20 A/g. The enhanced performance of BWO/ZnO/rGO composites suggested a potential material for supercapacitor electrodes. EDX result ensures the chemical purity level of synthesized nanocomposites according to the experiment design. The SEM results of the composites BWO/ZnO/rGO exhibit a 50–150 nm long short rod-like shape and an average diameter of approximately 50 nm. The XRD patterns of BWO, BWO/ZnO, and BWO/ZnO/rGO have crystallite sizes of 42.016, 44.845, and 59.784 nm respectively representing a gradual increase in size wt% of rGO increased in the composite.

Manganese doped La0.8Ba0.2FeO3 perovskite oxide as an efficient electrode material for supercapacitor

In this study, L0.8Ba0.2Fe1-xMnxO3 (LBFM-x, x = 0.0, 0.2, 0.5, 0.8) perovskite materials were synthesized by a Sol-Gel combustion method and were investigated as an electrode material for a supercapacitor device. The morphology, crystalline structure and electrochemical performance of the samples were studied in detail. The active points, where the electrochemical redox reaction takes place to store faradaic energy, are the oxygen vacancies on the surface of perovskite oxides. Partial substitution in the B-site of the perovskite structure, which is directly related to the oxygen vacancy in BO6 octahedral, is effective in optimizing the electrochemical performance. Based on the results of structural analysis, LBFM-0.2 has the highest concentration of oxygen vacancies; thus, it showed a higher electrochemical performance compared to other samples. The supercapacitors prepared with this electrode material should have an acceptably high specific capacitance of 685F.g-1 at a current density of 2.0A.g-1. The partial substitution of Mnn+ at the B-site increases the oxidation state of Fe cations and the mobility of oxygen ions through the oxygen vacancy sites. The electrochemical stability of LBFM-0.2, was evaluated by applying long charge-discharge cycles. After 3000 charge-discharge cycles, the supercapacitor was able to maintain about 94% of its initial capacity.

Na2Zn0.5Co0.5P2O7 Diphosphate: Sol-gel synthesis, physico-chemical studies, and prospects as a novel supercapacitor electrode material

For the first time, a mixed-metal diphosphate Na2Zn0.5Co0.5P2O7 has been successfully synthesized via the sol-gel method. The sample was characterized by means of XRD, DTA/TGA, SEM/EDX, UV–vis, Raman, IR and color measurements (CIE-L*a*b*). Its structure was determined through X-ray powder diffraction, in tetragonal system, with space group P42/mnm. The 3D structure of the material consists of infinite chains formed by [Zn/CoO4] tetrahedra and [P2O7] diphosphate units sharing corners. Sodium cations occupy two types of interstitial positions between the infinite chains [Zn/CoP2O7]2-. Raman and Infrared spectra of the studied phosphate have been investigated. A factor group analysis leads to determination of internal modes of the P2O74− anion. Tetrahedral environment of Co2+ ions was confirmed by mean of optical analysis, in which numerous bands in the region 475-675 nm, assigned to the forbidden and allowed d–d transitions of Co2+ are detected and the gap energy is extracted from Tauc and Kubelka-Munk plots. The prepared Na2Zn0.5Co0.5P2O7 diphosphate was extensively investigated for its potential use as an electrode material for supercapacitors. The electrode was prepared by depositing the active material on a conductive substrate (nickel foam) and demonstrated significant electrochemical performance with a specific capacitance of 277 F.g-1 at a scan rate of 5 mV.s-1. This outstanding performance underlines its relevance for supercapacitor applications.

Facile synthesis of MnMoO4 nanostructures arrays as novel electrode materials for high-performance symmetric and asymmetric supercapacitor

Facile synthesis of MnMoO4 nanostructures arrays as novel electrode materials for high-performance symmetric and asymmetric supercapacitor

Research progress in the development of transition metal chalcogenides and their composite-based electrode materials for supercapacitors

Research progress in the development of transition metal chalcogenides and their composite-based electrode materials for supercapacitors

Application of transition metal doped in boron carbide/graphene heterostructures as an electrode for supercapacitors

The density functional theory (DFT) is applied within the current piece of research for exploring the charge storage capacity, quantum or chemical capacitance (QC), electronic structures and the geometry of modified boron carbide (BC3)/graphene (Gr) heterostructure. Also, the impact of doping the Mn atom upon the capacitance behavior of BC3/Gr is explored. Based on the results, doping the Mn atom improved the QC of BC3/Gr. Moreover, doping the Mn atom was more effective than vacancy defect in enhancing the QC of BC3/Gr. The QC of the Mn-doped BC3/Gr was the highest (280.41 F/cm2), which demonstrates its potential application as an encouraging electrode material in supercapacitors (SCs). Based upon the DOS around the Fermi level, doping the Mn atom could be the reason for the increase in the QC. Finally, the results can provide useful insights into designing high-capacitance SCs.

One-step synthesis of double-walled NiCo2O4 hollow nanotubes using hollow fiber templates created by airflow-coaxial electrospinning

Metal oxide electrode material NiCo2O4 has significant potential for application as an Electrode material due to its excellent electrochemical performance and environmentally friendly characteristics. This paper utilizes a unique airflow-coaxial electrospinning technique combined with a simple one-step solution reaction to prepare NiCo2O4 nanotubes with a complex double-walled hollow structure. The XPS and XRD results demonstrated the synthesis of the NiCo2O4 materials, while the SEM and TEM results verified the presence of a double-walled hollow structure in the NiCo2O4 nanotubes. The electrochemical performance of the NiCo2O4 double-walled hollow nanotubes is significantly improved compared to those single-layer hollow nanotubes. The maximum specific capacitance of those two kinds of nanotubes is 437.5 F/g and 336.7 F/g under the current density of 1 A/g, respectively. The origin of the electrochemical performance improvement can be attributed to the increased specific surface area and the presence of interlayer ion transport channels in the double-walled hollow structure. The study is very helpful in improving the application prospect of NiCo2O4 material as the electrode material of supercapacitors. Equally important, this study also presents an efficient method to fabricate double-walled hollow nanostructures based on special templates.

Surfactant-assisted hydrothermal synthesis of FeVO4 nanoparticles for supercapacitor applications.

Due to their high capacitance, stability, and conductivity, binary transition metal oxides, such as iron vanadate, have the potential to be ideal electrode materials for supercapacitors. The effect of surfactants such as Polyethylene glycol (PEG), cetyltrimethylammonium bromide (CTAB), and thioglycolic acid (TGA) on the formation and properties (structural, morphological, optical and vibrational) of iron vanadate nanoparticles has been investigated using various analytical techniques. The results show that the surfactants significantly influence the morphology of the prepared FeVO4 nanoparticles. The nanoparticles prepared using TGA show a nano-mat like structure with the smallest particle size, and they were subjected to Cyclic Voltammetry analysis, showing a specific capacitance of 48 Fg−1 and demonstrating potential to be used for supercapacitors.

High-performance biomass tar-based nanofibers with CoNi nanosheets prepared by electrospinning for supercapacitor electrode material

Biomass-based nanofibers prepared by electrospinning have broad prospects in the field of supercapacitors. In this work, biomass tar-based carbon nanofibers (CNFs) are prepared by electrospinning technology, and the CoNi nanosheets are grown on the surface of CNFs. The obtained electrode materials have a three-dimensional open petal-like nanofiber structure, and the results of the electrochemical performances show that the CoNi@CNF-1 has a specific capacitance of 474.4F g−1 at 0.5 A g−1, an energy density of 65.9 Wh kg−1 and a power density of 250 W kg−1. After 5000 charge-discharge cycles, the CoNi@CNF-1 still maintains 95.4 % of its original capacitance in the three-electrode system. This work provides an important reference for the effective treatment of biomass tar and its application in the field of electrochemical energy storage.

Calcination process of porous metal–organic frameworks derived from nickel sulfide composites for supercapacitor and computer vision for investigating the porosity-electrochemical correlation

The utilization of metal–organic framework nanostructured electrode materials in supercapacitors and sensor applications is achieved by various chemical methods. In this study, we create NiS and NiS@MOF-BDC by employing nickel precursors and benzene dicarboxylic acid (BDC) as chelating organic linkers through a thermal reduction procedure at a temperature of 400 °C to produce the composite. The composite heterostructure enhanced the conductivity, porous characteristics, and diverse potential morphological qualities. The production of composite electrodes demonstrates a specific capacity of 260F/g (104C/g) when subjected to a current density of 1A/g. Additionally, these electrodes exhibit exceptional cyclic stability, enduring 5000 cycles, when used with a 2 M KOH electrolyte. Moreover, the synthesized composite HR-TEM images were analyzed using computer vision and AI techniques for estimating the porosity and investigating the enhanced electrochemical correlation.

Enhanced electrochemical performance of NiMn layered double hydroxides/graphene oxide composites synthesized by one-step hydrothermal method for supercapacitors.

This study aims to enhance the performance of supercapacitors, focusing particularly on optimizing electrode materials. While pure NiMn layered double hydroxides (LDHs) exhibit excellent electrochemical properties, they have limitations in achieving high specific capacitance. Therefore, this paper successfully synthesized composite materials of NiMn LDHs with varying loadings of graphene oxide (GO) using a hydrothermal method. Systematic physicochemical characterization of the synthesized materials, such as powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), and Raman spectroscopy, revealed the influence of GO doping on the microstructure and electrochemical performance of NiMn LDHs. Electrochemical tests demonstrated that the NiMn LDHs/GO electrode material exhibited optimal electrochemical performance with a specific capacitance of 2096 F g-1 at 1 A g-1 current density and 1471 F g-1 at 10 A g-1, when GO doping level was 0.45 wt%. Furthermore, after 1000 cycles of stability testing, the material retained 53.3% capacitance at 5 A g-1, indicating good cyclic stability. This study not only provides new directions for research on supercapacitor electrode materials but also offers new strategies for developing low-cost and efficient electrode materials.

Facile electrodeposition of CoMn2O4 nanoparticles on nickel foam as an electrode material for supercapacitors

In this study, we successfully utilized nickel foam (NF) as a scaffold for the direct deposition of ultra-thin CoMn₂O₄ (CMOs) through a one-step electrochemical deposition method. This was followed by annealing to produce a stable, free-standing electrode. This electrode was then used to develop an aqueous asymmetric supercapacitor (AASC). The optimized electrode demonstrated an exceptionally high specific capacitance of 2218.32 F g−1 at 1 A g−1 and excellent cyclic stability, retaining 86.67 % of its capacitance after 6000 cycles. An AASC device was also constructed, employing CMOs on NF as the cathode and commercially available activated carbon (AC) on carbon cloth (CC) as the anode. This configuration achieved a high energy density of 83.85 Wh kg−1 at a power density of 800.03 W kg−1, with robust cycling stability (∼87.16 % retention after 16,000 cycles at 30.0 A g−1) and nearly 100 % Coulombic efficiency. These results surpass those of many state-of-the-art supercapacitors (SCs), highlighting the significant potential for practical applications.

Enhanced Performance of Laser-Induced Graphene Supercapacitors via Integration with Candle-Soot Nanoparticles.

Laser-induced graphene (LIG) has been emerging as a promising electrode material for supercapacitors due to its cost-effective and straightforward fabrication approach. However, LIG-based supercapacitors still face challenges with limited capacitance and stability. To overcome these limitations, in this work, we present a novel, cost-effective, and facile fabrication approach by integrating LIG materials with candle-soot nanoparticles. The composite electrode is fabricated by laser irradiation on a Kapton sheet to generate LIG material, followed by spray-coating with candle-soot nanoparticles and annealing. Materials characterization reveals that the annealing process enables a robust connection between the nanoparticles and the LIG materials and enhances nanoparticle graphitization. The prepared supercapacitor yields a maximum specific capacitance of 15.1 mF/cm2 at 0.1 mA/cm2, with a maximum energy density of 2.1 μWh/cm2 and a power density of 50 μW/cm2. Notably, the synergistic activity of candle soot and LIG surpasses the performances of previously reported LIG-based supercapacitors. Furthermore, the cyclic stability of the device demonstrates excellent capacitance retention of 80% and Coulombic efficiency of 100% over 10000 cycles.

Morphology Modulation of ZnMn2O4 Nanoparticles Deposited In Situ on Carbon Cloth for Supercapacitors

As a typical spinel structure material, ZnMn2O4 has been widely researched in the field of electrode materials. However, ZnMn2O4 nanoparticles as electrode materials for supercapacitors have the disadvantages of low conductivity, inferior structural integrity, and easy aggregation, resulting in unsatisfying electrochemical performance. In this work, we use a hydrothermal method and high-temperature calcination to deposit ZnMn2O4 nanoparticles on carbon cloth and explore the influence of hydrothermal reaction time on the deposition morphology and distribution of ZnMn2O4 nanoparticles on carbon cloth. The deposition process of ZnMn2O4 nanoparticles on carbon cloth was analyzed, and a ZMO-9 electrode was deduced to be the most suitable electrode for supercapacitors. A series of electrochemical performance tests show that the ZMO-9 electrode has excellent specific capacitance (specific capacity) (499 F·g−1 (299.4 C·g−1) at a current density of 1 A·g−1) and rate performance (75% capacitance retention at a current density of 12 A·g−1). The assembled asymmetric supercapacitor has an energy density of 46.6 Wh·kg−1 when the power density is 800.1 W·kg−1. This work provides a reference for the structural design of ZnMn2O4 supercapacitor electrode materials and the improvement of electrochemical properties.

Effect of interlayer thickness on electrochemical properties and corrosion resistance of sputtered TiNxnm/Tixnm multilayer thin films

Three multilayers [TiNxnm/Tixnm/p-type Si (100)] (x = 2.5, 5, 10) were fabricated using a dc-magnetron sputtering to evaluate surface and interfacial effect on electrochemical properties for possible application in supercapacitor electrode materials. The (111) and (101) planes of TiN and Ti were observed at 36.50° and 40.19° respectively. TA, LA, and TO phonon modes were found at 254.12, 306.15, and 637.94 cm−1, respectively. The defect state distribution of Ti, N, and O was investigated from PL. XPS confirmed the Ti at. % of TiNxnm/Tixnm multilayers decreased from 43.07 to 12.04 and N at. % increased from 42.79 to 72.53 % as the x value decreased from 10 nm to 2.5 nm. The areal specific capacitance (Ca) and energy density (E) of the TiNxnm/Tixnm multilayer electrode increased with decreasing multilayer thickness. E varied from 0.27 to 1.37 mWhcm−2 and the power density (P) from 5.04 to 25.4 mWcm−2 for the multilayers. The diffusion coefficient (D) and total accumulated charge (Qin) decreased from 6.48 × 10−17 to 1.56 × 10−18 cm2/s and 1.82 to 1.64 C/cm2, respectively, for TiNxnm/Tixnm multilayers. The capacitive contribution was the highest in x = 10 (2.181 Av−1s). However, the diffusion-limited contribution was maximum in x = 5 (3.541 Av−1/2s1/2). The cyclic stability maintained at 85.4 % capacitive retention over 1000 cycles and the expansive potential window (up to 0.8 V in 1 M H2SO4) makes the multilayer thin films ideal for supercapacitor electrodes. Among all the samples, the TiN2.5nm/Ti2.5nm exhibited the highest Ca, E, and diffusion coefficient, originating from the smaller layer thickness, leading to more ohmic conductivity and facilitating the supercapacitive performance.

Novel three-dimensional architectured ZnMgAl ternary layered double hydroxide@reduced graphene oxide nanocomposites as electrode material for high-performance supercapacitor

Ternary layered double hydroxides (LDH) have recently attracted immense attention owing to their stupendous features, such as fine compositional tuning, multiple valence states, and superior electrochemical activity. Moreover, their intriguing structures and distinctive physiochemical properties delineate them as an exemplary material to serve as electrodes for high-performance supercapacitors (SCs). The present work reports the in-situ synthesis of Zinc Magnesium Aluminium LDH (ZMA) integrated with reduced graphene oxide (rGO) through a single-step hydrothermal approach. The resulting novel ternary ZMA@rGO nanocomposite (ZMAG) possesses a unique architecture incorporating hierarchical 3D nanoflowers of ZMA embedded on graphene nanosheets. The porous morphology of LDH improves interfacial charge transport, which results in more faradaic reactions at the electrochemically active sites. In addition, the conductive graphene nanosheets render a high specific surface area, endowing excellent capacitive behavior. The amalgamated electrochemical properties of ZMA and rGO develop a competent electrode material (ZMAG) for SCs. The ZMAG2 nanocomposite having ZMA and rGO in 1:1, evinces a specific capacitance (Cs) of 656.7 F/g at a current density (Id) of 1 A/g. Furthermore, the asymmetric supercapacitor (ASC) features admirable cycle stability (retains 89% of initial capacitance after 15,000 charge/discharge cycles). Herein, the real-time application of ZMA@rGO//AC ASC has also been demonstrated. Therefore, hierarchical porous nanostructure proclaims new prospects for fabricating proficient electrode materials for energy storage devices.

Aftermath of Ag embedding on structural, optical, and supercapacitor electrode attributes of USP-grown CuO thin films

Here, ultrasonic spray pyrolysis method (USP) was utilized to produce pure and silver doped copper oxide nanostructures on glass substrates. Thereafter, several characterization techniques were conducted on the grown samples to delve into their morphological, structural, electrochemical, and optical aspects. The mentioned analyses were carried out by performing x-ray photoelectron spectroscopy, scanning electron microscope, X-ray diffraction, electrochemical impedance spectroscopy, galvostatic charge-discharge, cyclic voltammetry, and UV–visible spectroscopy measurements. Thus, the impact of silver impurity doping on the relevant aspects of host material were recorded as well as the features of unspoiled copper oxide films. Accordingly, the samples, as indicated by X-ray diffraction results, possessed (002) preferential plane orientation of copper oxide material along with the crystallite sizes ranging from 52.52 nm to 75.02 nm due to the imperfections caused by the silver doping. The scanning electron microscope images exhibited that the silver doping did not form significant modifications in the host material morphology where nanowire-like structures observed. The presence of the suggested materials in the films was verified by the x-ray photoelectron spectroscopy. Also, the UV–visible spectroscopy measurements detected that optical absorbance edge and bandgap energy values red shifted as a result of the impurity doping. The electrochemical supercapacitors performances of the silver doped copper oxide nanostructured thin films were inspected by using the GCD, EIS, and CV. The silver doped copper oxide films demonstrated a specific capacitance value of 66 F/g at a current density of 1 A/g in 1 M KOH electrolyte. From Nyquist plot, Rs, Rcor, Rpo, Ccor and Cc were obtained as 2.327 × 103 Ω.cm2, 43.63 × 103 Ω.cm2, 4.580 × 103 Ω.cm2, 111.5 × 10-6 S*s^a. cm-2 and 101.1 × 10-6 S*s^a. cm-2, respectively. The results indicated that the electrochemically synthesized the silver doped copper oxide electrodes can be obtained and developed as an alternative electrode material for supercapacitors (SCs).

Synthesis and characterization of CuFe2O4 spinel ferrite for supercapacitor application

The present work describes the synthesis of spinel ferrites which is potentially active material for electrodes of supercapacitors with high theoretical capacitance. Using nitrate salts of respective metal ions with citric acid as a chelating agent CuFe2O4 spinel ferrite was prepared by using the sol-gel auto-combustion method. The formation of single-phase nano particles of CuFe2O4 spinel ferrite is confirmed form the X-ray diffraction pattern. The spherical morphology of copper ferrite nano particles is displayed by Field-emission Scanning Electron Microscopy. The electrochemical properties of CuFe2O4 spinel ferrite has been investigated by Cyclic Voltammetry (CV) and Galvanostatic Charge-Discharge (GCD) tests. The specific capacitance of the prepared CuFe2O4 spinel ferrite is 238 F/g at the current density of 0.5 A/g. The corresponding power density is 118.29 W/kg and the energy density is 62.5 Wh/kg. The resultant CuFe2O4 spinel ferrite nanoparticles exhibit excellent electrochemical performance and can be a promising candidate for supercapacitor application.

Carbon-modified NiCo2O4 as an electrode material for supercapacitors

Transition metal oxides are a promising class of electrode materials for pseudocapacitors due to their high electrochemical activity and eco-friendly nature. However, they possess poor intrinsic conductivity which results in the low energy density of the assembled supercapacitors. In this study, electrodes composed of amorphous C-modified NiCo2O4 (C/NiCo2O4/NF) on nickel foam substrate were prepared by electrochemical deposition and thermostatic heating method. The incorporation of amorphous C compensates for the low electrical conductivity of NiCo2O4 materials, thereby significantly enhancing the electrochemical performance. The galvanostatic charge-discharge (GCD) test results reveal an impressive specific capacitance of 379.4 mF/cm2 at a current density of 1.5 mA/cm2, and with a capacitance retention rate of 87.1 %. In addition, the symmetric supercapacitor assembled using C/NiCo2O4 electrode materials exhibits exceptional energy density and power density, reaching maximum values of 522.3 μWh/cm2 and 900 μW/cm2 respectively. The device is capable of illuminating LED for up to 8 min, further demonstrating its practical applicability. These results underscore the feasibility and promise of C/NiCo2O4 as an electrode material for the advancement of high-performance supercapacitors.