Electrode Material For Electrochemical Supercapacitors Research Articles

Screen-Printed Stretchable Supercapacitors Based on Tin Sulfide-Decorated Face-Mask-Derived Activated Carbon Electrodes with High Areal Energy Density

Screen-Printed Stretchable Supercapacitors Based on Tin Sulfide-Decorated Face-Mask-Derived Activated Carbon Electrodes with High Areal Energy Density

Fabrication of hierarchically structured supercapacitor using N and S co‐doped activated carbons derived from Samanea saman biomass

AbstractBiomass‐derived activated carbons have emerged as highly promising electrode materials for electrochemical supercapacitors due to their remarkable characteristics, such as high surface area, cost‐effectiveness, and environmental sustainability. This study focuses on the synthesis of N and S co‐doped activated carbons (NSACs) from Samanea saman (rain tree) biomass through a combined hydrothermal‐chemical activation process. Leveraging the advantageous hierarchical structure inherent to biological sources, the resulting NSACs demonstrate enhanced ion transport, leading to remarkable capacity and power density. The NSACs synthesized by pyrolysis at 800°C exhibit exceptional specific capacitances of 434 and 401 Fg−1 in Na2SO4 and H2SO4 electrolytes, respectively, in a three‐electrode system. The capacitance retention of the same NSAC was found to be 77.6% at a corresponding current density of 10 Ag−1 in H2SO4 electrolyte. This outstanding electrochemical performance can be attributed to the material's high specific surface area (1402 m2 g−1), well‐defined hierarchical porous structure, and a substantial degree of graphitization. A symmetric supercapacitor constructed using the synthesized NSACs demonstrates notable energy densities of 14.5 and 25.0 Whkg−1, with H2SO4 and Na2SO4 electrolytes respectively. Furthermore, the symmetric supercapacitor exhibits excellent stability, retaining 91.3%–94.3% of its capacity after 5000 consecutive GCD cycles with H2SO4 and Na2SO4 electrolytes, respectively. The synergistic combination of the unique characteristics of NSACs derived from Samanea saman biomass presents a promising avenue for the development of high‐performance and environment‐friendly supercapacitors.

B-site disorder driven Griffiths-like phase and electrochemical behavior in Y2NiCrO6 double perovskite

In this investigation, nanoparticles of B-site disordered Y2NiCrO6 (YNCO) double perovskite were synthesized by the facile sol–gel method to evaluate their magnetic and electrochemical properties. Their crystallographic structure is monoclinic and the average size of the particles is 79±16 nm. XPS analysis indicated a mixed oxidation states of B-site transition metals Ni2+/Ni3+ and Cr2+/Cr3+. The mixed valence states of Ni and Cr, along with the mixed magnetic phases of YNCO, constitute a signature of the B-site disorder. This antisite disorder contributed to the observation of a Griffiths-like phase arising from ferromagnetic short-range interactions above the magnetic transition up to the Griffiths temperature, T G = 137 K. The synthesized YNCO double perovskite demonstrated a promising behavior as an electrode material for electrochemical supercapacitors. In a three-electrode system, it displayed a specific capacitance of 270 F g−1 at a current density of 0.5 A g−1. In a symmetric two-electrode system, YNCO exhibited a specific capacitance of 180 F g−1 at 0.5 A g−1, alongside an energy density of 6.25 Wh kg−1 at 250 W kg−1 power density. In both cases, we employed a mild 0.5 M neutral aqueous Na2SO4 solution as the electrolyte, in contrast to the typically employed corrosive and concentrated alkaline aqueous solution. The fascinating magnetic and charge storage properties of the B-site disordered YNCO double perovskite indicate its potential for use in spintronic devices and as efficient electrodes in symmetric hybrid supercapacitors.

High specific capacitance and NTC behavior of substituted cobalt oxide spinels for electrochemical supercapacitor and thermistor applications

Due to the growing importance of low-cost energy storage devices in smart device applications, finding an appropriate electrode material with the least self-discharging, high power, and energy densities is the need of the hour. In this paper, Cu and Mn-modified Co3O4 spinels in the form of CuCo2O4 and MnCo2O4 are reported as the most promising electrode materials for high-performance electrochemical supercapacitors. Modified Co3O4 spinels were prepared by the co-precipitation technique, and the X-ray diffraction (XRD) studies show a single-phase formation with cubic crystal symmetry. The average crystallite size estimated by considering the highest intensity peak of the diffraction pattern using Scherrer’s relation shows the average crystallite size below 30 nm for reported spinels. Scanning electron microscopic (SEM) images stabilize the fact that grains with nanosizes consisting of regular shapes and excellent morphological features. The dc-conductivity measurement establishes the essence of negative temperature coefficient of resistance (NTCR) behavior in nanostructured spinels. The specific capacitance (Cs) of CuCo2O4 and MnCo2O4 estimated using cyclic voltammetry (CV) was found to be 616.074 F g−1 and 1401.16 F g−1 for a scan rate of 10 mV s−1 with verified stability up to 1000 cycles. The low internal resistance value in the range of 0.1 Ω for both the spinels verified by the electrochemical impedance spectroscopy (EIS) graph confirms these spinels as encouraging electrode materials for electrochemical supercapacitors.

Application of dandelion-like Sm2O3/Co3O4/rGO in high performance supercapacitors.

Novel 2D material-based supercapacitors are promising candidates for energy applications due to their distinctive physical, chemical, and electrochemical properties. In this study, a dandelion-like structure material comprised of Sm2O3, Co3O4, and 2D reduced graphene oxide (rGO) on nickel foam (NF) was synthesised using a hydrothermal method followed by subsequent annealing treatment. This dandelion composite grows further through the tremella-like structure of Sm2O3 and Co3O4, which facilitates the diffusion of ions and prevents structural collapse during charging and discharging. A substantial number of active sites are generated during redox reactions by the unique surface morphology of the Sm2O3/Co3O4/rGO/NF composite (SCGN). The maximum specific capacity the SCGN material achieves is 3448 F g-1 for 1 A g-1 in a 6 mol L-1 KOH solution. Benefiting from its morphological structure, the prepared composite (SCGN) exhibits a high cyclability of 93.2% over 3000 charge-discharge cycles at 10 A g-1 and a coulombic efficiency of 97.4%. Additionally, the assembled SCGN//SCGN symmetric supercapacitors deliver a high energy density of 64 W h kg-1 with a power density of 300 W kg-1, which increases to an outstanding power density of 12 000 W kg-1 at 28.7 W h kg-1 and long cycle stability (80.9% capacitance retention after 30 000 cycles). These results suggest that the manufactured SCGN electrodes could be viable active electrode materials for electrochemical supercapacitors.

Rapid hydrothermal green synthesis of core-shell-shaped NiCo2O4@MoS2/RGO ternary composites for high-performance electrode materials

RGO-based composites possess great potential as materials for supercapacitors owing to their remarkable properties such as high specific surface area and electrical conductivity. Herein, this work presents an investigation on ternary composite electrode materials composed of RGO, NiCo2O4, and MoS2. The chemical insertion method was employed to overcome the issue of RGO layer repacking. By means of a rapid green hydrothermal synthesis approach, conductive MoS2/RGO substrates were successfully fabricated, and subsequently, NiCo2O4@MoS2/RGO core–shell-shaped composites were prepared using the MoS2/RGO substrates. The ternary NiCo2O4@MoS2/RGO composites were composed of uniformly distributed conductive MoS2/RGO substrates embedded with NiCo2O4 core microspheres. Remarkably, the NiCo2O4@MoS2/RGO composites, used as electrode materials in supercapacitors, exhibited an exceptional specific capacitance of 946 F g-1 at 1 A g-1, improved rate capacity, and demonstrated outstanding electrochemical stability while maintaining 87.3 % retention after 5000 consecutive charge–discharge cycles. The exceptional integrated performance of these composites renders them promising electrode materials for electrochemical supercapacitors.

Covalently anchored benzimidazole-reduced graphene oxide as efficient electrochemical supercapacitor electrode material

Covalently anchored benzimidazole-reduced graphene oxide as efficient electrochemical supercapacitor electrode material

Facile synthesis of layered double hydroxides nanospheres and their electrochemical supercapacitor property dependent morphology

We fabricated a nanosphere-like layered double hydroxide (LDH) as a feasible electrode material for electrochemical supercapacitors. The electrochemical performances of NixCoy-LDHs with different proportions of Ni and Co were studied to discover the relationship between morphology and supercapacitor property. The Ni1Co4-LDH showed the best capacitance performance compared to Ni1Co1-LDH and Ni4Co1-LDH. The more curly sheets on the surface of Ni1Co4-LDH may have resulted in the increase of the capacitance due to the increasing conductivity. It is evident that besides changing the state of sheets on the surface of NixCoy-LDHs, the Co content may also influence the capacitance performance of NixCoy-LDHs.

A review on effect of conducting polymers on carbon-based electrode materials for electrochemical supercapacitors

Supercapacitors, commonly referred to as electrochemical capacitors, are a significant type of energy storage devices with more energy density than capacitors, greater power density, and longer cycle life than batteries. Conventionally, the electrode material of supercapacitors is composed of metal oxides, inorganic complexes, carbon-based materials, and conducting polymers. Researchers have attempted numerous combinations of aforementioned materials to create electrode material with enhanced electrochemical properties. However, supercapacitor (SC) electrodes constructed with pure conducting polymers (CPs) have poor cycling stability, resulting in a rapid decrease in specific capacitance. To improve the electrochemical property of such materials, researchers have attempted to construct binary and ternary composites of various CPs by mixing them with carbonaceous materials and metal oxides. In this review, SC electrode materials prepared from CPs, such as polyaniline (PANI), polythiophene (PTh), polypyrrole (PPy) and their composites with carbonaceous materials such as activated carbon (AC), carbon nanotubes (CNTs), reduced graphene oxide (rGO), graphene and carbon quantum dots have been discussed.

Effect of pyrolysis temperature on carbon materials derived from reed residue waste biomass for use in supercapacitor electrodes

Activated carbon (AC) obtained by the pyrolysis of reed residue waste has been investigated for its potential application as a high-performance electrode material in supercapacitors. Four different pyrolysis temperatures (500, 600, 700, and 800 °C) were implemented, and the optimum pyrolysis temperature was determined on the basis of the physicochemical properties and electrochemical measurements of the AC materials. AC obtained at a relatively low pyrolysis temperature of 600 °C (denoted as C/600 °C) presented a Hemistepta lyrata (bunge flower)-like porous nanostructure with a high specific surface area of 2074.72 m2 g−1 and a large pore volume of 0.930 cm3 g−1. SEM and Raman spectroscopy have been used to inspect the surface morphology and assess the degree of graphitization of the AC materials. Electrochemical performances have been assessed by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. Sample C/600 °C displayed a relatively large capacitance of 228 F g−1 at a current density of 1 A g−1 in 6 m KOH as the electrolyte, and it retained very good cyclic stability with a capacitance retention of 98.1% after 8000 cycles at a current density of 5.0 A g−1. The results imply that C/600 °C derived from reed residue waste constitutes a promising electrochemical supercapacitor electrode material.

Electrochemical capacitance properties of pre-sodiated manganese oxide for aqueous Na-ion supercapacitors.

Mn-based oxides are widely investigated as electrode materials for electrochemical supercapacitors, because of their high specific capacitance in addition to the high abundance, low cost, and environmental friendliness of Mn. The pre-insertion of alkali metal ions is found to improve the capacitance properties of MnO2. While the capacitance properties of MnO2, Mn2O3, P2-Na0.5MnO2, and O3-NaMnO2etc. are reported, there is no report yet on the capacitive performance of P2-Na2/3MnO2, which has already been studied as a potential positive electrode material for Na-ion batteries. In this work, we have synthesized sodiated manganese oxide, P2-Na2/3MnO2 by a hydrothermal method followed by annealing at a high temperature of about 900 °C for 12 h. For comparison, manganese oxide Mn2O3 (without pre-sodiation) is synthesized by following the same method, but annealing at 400 °C. While P2-Na2/3MnO2 exhibits a high specific capacitance of 234 F g-1, Mn2O3 can deliver only 115 F g-1 when cycled at 0.4 A g-1 in an aqueous electrolyte of 1.0 M Na2SO4 in a three-electrode cell. An asymmetric supercapacitor Na2/3MnO2‖AC is assembled, which can exhibit a SC of 37.7 F g-1 at 0.1 A g-1 with an energy density of 20.9 W h kg-1, based on the total weight of Na2/3MnO2 and AC with an operational voltage of 2.0 V and possesses excellent cycling stability. This asymmetric Na2/3MnO2‖AC supercapacitor can be cost-effective considering the high abundance, low-cost and environmental friendliness of Mn-based oxides and aqueous Na2SO4 electrolyte.

High-capacity MnCo2O4/NiCo2O4 as electrode materials for electrochemical supercapacitors

In recent decades, investigations on eco-friendly energy storage devices to cope with the energy crisis and alleviate environmental pollution have garnered immense attention. Moreover, supercapacitors commercialization requires finding affordable, stable electrode nanomaterials of sufficient capacitance. Recent research has shown new hope for using two metal oxides together. Therefore, the present study introduced MnCo2O4/NiCo2O4 with star morphology on a nickel foam substrate as a cost-effective electrode for the first time. This electrode was prepared by a simple hydrothermal method in which MnCo and NiCo2O4 were deposited on nickel foam via a two-stage synthesis process. Furthermore, a particular star-like morphology was obtained by altering the synthesis temperature and time. The galvanostatic charge-discharge (GCD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were employed to assess the electrochemical properties of the electrodes by the three-electrodes system in a 3 M KOH solution. The synergistic effect of MnCo2O4 with NiCo2O4 led to an excellent capacitance of 1276 F/g and stability of 96.4% following 5000 consecutive CV cycles. Finally, the NiCo2O4/MnCo2O4 supercapacitor application was investigated in an asymmetric supercapacitor as the positive electrode, with rGO being the negative electrode. The results indicated satisfactory performance with a power density of 540 W/kg and an energy density of 68 W h//kg.

Recent development of carbon electrode materials for electrochemical supercapacitors

Supercapacitors have gained much attention due to their remarkable merits such as stable cycle performance, high power density and excellent charge and discharge performance at high rate. From this perspective, carbon-based materials are widely explored as the active electrode materials for supercapacitors by taking advantages of hierarchical porous structure, excellent chemical stability, multistage pore structure, high surface area, and excellent conductivity. Various studies have explored many methods to utilize carbon-based electrodes. The large amount of defects inside carbon materials including functional groups, heteroatoms, name as foreign-doping, can provide pseudocapacitance. Meanwhile, self-doping (voids, vacancies, defects, etc.) may also enhance the electric double-layer capacitance. In this context, a brief overview of carbon materials for supercapacitor is expounded, including their characteristics, development process and the future challenges, providing a referential guide to those new to this field.

Facile synthesis of nickel-based bimetallic metalorganic frameworks with different cobalt ratios as electrode material for electrochemical supercapacitors

Facile synthesis of nickel-based bimetallic metalorganic frameworks with different cobalt ratios as electrode material for electrochemical supercapacitors

In situ grown of thulium/samarium mixed metal–organic frameworks onto Ni foam as outstanding binder-free battery type high-performance electrode for supercapacitors

In this paper, a sphere-like thulium/samarium mixed-metal MOF with 1-imidazole-carboxylate (IMC) as the organic linker (i.e. Tm,Sm-IMC-MOF) was grown onto Ni-foam (NF) porous support by one-step cathodic deposition procedure. The synthesized Tm,Sm-IMC-MOF material was characterized through XRD, FT-IR, TGA/DSC and FE-SEM/EDS techniques. The charge storage performance of the fabricated Tm,Sm-IMC-MOF/NF electrode was analyzed through CV and GCD tests, where a battery-like supercapacitive ability with a highest capacity of 645 C/g at 1 A/g was observed. The assembled Tm,Sm-IMC-MOF/NF//RGO/NF ASC device showed specific capacity of 239 C/g, areal capacity of 2.11 C cm−2 at 4 A/g and ~63 % capacity retention after increasing the applied current load from 1 to 20 A/g. The assembled ASC device exhibited 85.4 % and 91.5 % cycling retentions after 5000 cycles at 4 and 8 A/g, respectively. These results demonstrated that the fabricated Tm,Sm-IMC-MOF/NF electrode could be a promising candidate as active electrode material for electrochemical supercapacitors.

CeO2-clay composites for ultra-long cycle life electrochemical capacitive energy storage application

The lattice expansion caused by the reduction of Ce(IV) to Ce(III) impeded the development of the CeO2 as an effective electrode material for electrochemical supercapacitors. Herein, we prepared CeO2-clay composites through a one-step hydrothermal method. The interlayer structures of clays efficiently accommodate volume changes induced by crystal lattice expansion to achieve ultra-long cycle stability. After 60000 charge–discharge cycles, the capacitance retention rate of the assembled asymmetric supercapacitors is as high as ∼100%. The key findings of this work reveal the potential application of clays in achieving ultralong cycle stability of the CeO2 electrode material, paving the way for further application of the CeO2 in electrochemical energy storage.

One-step electrodeposition of a polypyrrole/NiO nanocomposite as a supercapacitor electrode

An electrochemical deposition technique was used to fabricate polypyrrole (Ppy)/NiO nanocomposite electrodes for supercapacitors. The nanocomposite electrodes were characterized and investigated by Fourier transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS). The performance of supercapacitor electrodes of Ppy/NiO nanocomposite was enhanced compared with pristine Ppy electrode. It was found that the Ppy/NiO electrode electrodeposited at 4 A/cm−2 demonstrated the highest specific capacitance of 679 Fg−1 at 1 Ag−1 with an energy density of 94.4 Wh kg−1 and power density of 500.74 W kg−1. Capacitance retention of 83.9% of its initial capacitance after 1000 cycles at 1 Ag−1 was obtained. The high electrochemical performance of Ppy/NiO was due to the synergistic effect of NiO and Ppy, where a rich pores network-like structure made the electrolyte ions more easily accessible for Faradic reactions. This work provided a simple approach for preparing organic–inorganic composite materials as high-performance electrode materials for electrochemical supercapacitors.

Investigations of 2D Ti 3 C 2 ( MXene )‐ CoCr 2 O 4 nanocomposite as an efficient electrode material for electrochemical supercapacitors

Investigations of <scp> 2D Ti ₃ C ₂ </scp> ( <scp>MXene</scp> )‐ <scp> CoCr ₂ O ₄ </scp> nanocomposite as an efficient electrode material for electrochemical supercapacitors

Heterogeneous Catalysis in Organic Transformations

In this study, we report a series of carbon/nickel-based composites. The composites are prepared through a facile one-pot solution combustion method by using nickel nitrate hydrate (Ni(NO3)2·6H2O) as an oxidizer and glucose (C6H12O6) as a fuel material. The phase, component and electrochemical capacitive behavior of the as-prepared samples are investigated. The component of the obtained composites could be simply controlled by changing the ratio of NO3−/C6H12O6. Novel C/Ni3(NO3)2(OH)4 composites are obtained at high molar ratio of NO3−/C6H12O6 (larger than 9) for the first time. The as-prepared C/Ni3(NO3)2(OH)4 composite shows battery-type behavior and exhibits a specific capacity of 630 C g−1 (1260 F g−1) at the current density of 1 A g−1, which is ca. 2–10 fold higher than those of C/NiO composite (414 C g−1, 828 F g−1) and C/NiO/Ni composite (65 C g−1, 129 F g−1). In addition, C/Ni3(NO3)2(OH)4 composite exhibits an excellent rate performance (448 C g−1, 996 F g−1 at 10 A g−1) and good cyclic stability. The results indicate that the C/Ni3(NO3)2(OH)4 composite is a potential electrode material for electrochemical supercapacitor. This work also suggests that the solution combustion process is promising for large-scale production of materials for supercapacitors.

The effect of synthesis temperature on the structural and electrochemical properties of S and N doped rGO electrodes

As the demand for alternative energy sources grows, new electrode materials for electrochemical supercapacitors are being developed. Heteroatom doped rGO sheets have attracted much attention in recent time. S and N doped rGO was prepared at various temperatures by a simple and low cost hydrothermal method in the present work. The successful formation of S and N doped rGO sheets is confirmed by structural characterization of prepared samples. The EDX and BET surface analysis shows the optimum doping of S and N and the highest surface area in SNrGO-140 sample, respectively. The electrochemical profile study shows that the SNrGO-140 has the maximum specific capacitance value of 332.5 F/g at a scan rate of 10 mV/s. The result observed suggested that S and N doped rGO prepared at 140 °C is the suitable electrode material to be used in high energy electrochemical supercapacitors.