Novel Electrode Material For Supercapacitors Research Articles

A novel carbonized natural silk nanofiber/graphene oxide aerogel for supercapacitor

In this study, we established a novel electrode material for supercapacitors using carbonizing natural silk nanofibers/graphene oxide (SNF/GO) aerogel. Particularly, the SNF/GO electrode fabricated at 800 °C carbonization exhibited unique microstructure, high stability. In terms of its electrochemical performances, the 800 °C SNF/GO electrode showed lower resistance and higher capacitance. After 10,000 cycles of charging, the 800 °C SNF/GO supercapacitor presented remarkable capacitance stability, indicating great potential in supercapacitor and other energy storage systems.

Iron oxide induced preparation of nanoscrolls of reduced graphene oxide for electrochemical charge storage applications

Fe3O4 - reduced graphene oxide nanoscrolls (FRGNS) are tailored for fabricating electrode material for supercapacitor applications. The scrolling of reduced graphene oxide is initiated by the magnetic field produced by the superparamagnetic iron oxide NPs. The formation mechanism and critical concentration of nanoparticles required for scroll formation is investigated by varying the weight ratio of iron oxide NPs. The nanoscroll formation is completely reversible and reproducible. The unique end open morphology of nanoscrolls facilitates the electrolytic accessibility and the Fe3O4 NPs favor the redox reactions as well. At a current density of 1Ag-1, FRGNS12 (rGO: Fe3O4 1:12) achieve a noteworthy specific capacitance value of 1498 Fg-1 within a potential ranging from 0 to −0.73 V in 1 M Na2S2O3 with exceptional energy density of 110.9 Wh Kg−1 and power density of 405 Wkg-1. A prominent cycling stability of 88% capacitance retention after 4000 cycles is also obtained. The electrochemical performance of opened as well as regenerated scrolls (RFRGNS12) are also evaluated. The specific capacitance increases to 1514 Fg-1 for RFRGNS12 due to the further exfoliation of rGO sheets take place during the unscrolling and scroll regeneration process. The unique fabrication methodology for the synthesis of graphene nanoscrolls and their utilization as electrode material for supercapacitors paves a new pathway for the advancement of novel electrode materials for supercapacitors.

Predominated capacitive behavior of Ag-doped magnesium vanadate as a novel electrode material for supercapacitors

Transition metal vanadate nanostructures are getting significant importance as an efficient electrode material for modern energy storage applications. In this work, a simple hydrothermal method is employed for the synthesis of magnesium vanadate (MgV2O5) and Ag-doped magnesium vanadate (Ag doped MgV3O8) nanomaterials. The X-ray diffraction (XRD) analysis reveals the formation of an orthorhombic structure for magnesium vanadate, whereas the Ag-doped magnesium vanadate results in a monoclinic structure. Interestingly, the optical bandgap is observed to increase from 2.85 eV to 3.92 eV with the increase in Ag-doping as revealed from Tauc's plot of the UV-visible absorption spectrum. The electrochemical performance of magnesium vanadate electrodes is thoroughly investigated by cyclic voltammetry (CV), Galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy. The Ag-doped magnesium vanadate shows higher specific capacitance (Cs = 706 Fg−1) in comparison to undoped (325 Fg−1) at a current density J = 5 Ag−1. The theoretical investigations through Dunn's model demonstrate a major contribution arises from surface-controlled processes, which increase as high as 91% at scan rate of 60 mVsec−1. Our findings indicate that Ag-doping significantly improves the overall electrochemical response of magnesium vanadate as an efficient electrode material for supercapacitor applications.

One-pot synthesis of NiO-MnCo2O4 heterostructure hollow spheres via template-free solvothermal method for high-performance supercapacitors

Supercapacitors employ transitional metal oxides as pseudocapacitive materials have drawn great attention owing to their prominent energy storage performances, but most of them are concentrate on simplex metal oxides. In this work, we reported a novel electrode material for supercapacitors composed of NiO-MnCo2O4 heterostructure hollow spheres via a facile and one-pot route. The resulting hybrid electrode material demonstrates a high specific capacity of 660 C g−1 at 1 A g−1. An assembled hybrid supercapacitor based on this unique heterostructure hollow spheres as positive electrode and nitrogen doped hierarchically porous carbon as negative electrode indicates a favorable energy density of 40 Wh kg−1 at 750 W kg−1 and long cycling lifespan of nearly 90% capacity retention rate after 5000 cycles. This work not only produces a competitive electrode material for energy storage devices but also offers a feasible strategy for producing complex transitional metal oxides materials with high capacitive performance.

Study of pristine and functionalized V2C and Mo2C MXenes as novel electrode material for supercapacitors

The quantum capacitance (QC) of pristine and functionalized molybdenum carbide and vanadium carbide MXenes is determined using density functional theory to investigate their suitability as supercapacitor electrodes. The calculations are performed using Synopsys ATK package with PBE functional under generalized gradient approximation keeping the energy cut off at 540 eV and k-point sampling at 12 × 12 × 1. The calculated QC at Fermi level in case of V2C and Mo2C exhibit extremely high values of 3465.51 and 3243.99 μF/cm2 respectively. The values of QC remain high in both positive and negative bias region around Fermi level. The impact of functionalization is studied for functional groups OH, OCH3, F and O. For each functional group, two layers are added (one below and one above) to the pristine structure. Band structures of functionalized MXenes show that the metallic character of the MXenes is retained, except in the case of oxygen functionalized Mo2C, which turns out to be a semiconductor with band gap of 0.051 eV. Although some decrease in density of state (DOS) and QC is observed in functionalized MXenes with all functional groups. However, the values are still good enough for supercapacitor electrode applications. The effect of number of layers of pristine MXene is also studied up to three layers and an increase in QC is observed with increase in number of layers.

Flower-like g-C3N4 nanosheets decorated hollow Co2NiO4 cube derived from ZIF-67 for excellent performance supercapacitors

In this study, zeolite imidazole framework 67 (ZIF-67)-derived Co 2 NiO 4 cubes decorated with flower-like g-C 3 N 4 nanosheets (CN) were reported as novel electrode materials for supercapacitors with excellent capacitance and cycling stability. The prepared composite material was synthesized by a simple solvothermal method, and its structural characteristics were revealed by XRD, SEM and FT-IR spectroscopy. Moreover, cyclic voltammetry, constant current charge/discharge test and AC impedance test were used to study the electrochemical behavior of composite materials. The results showed that by combining Co 2 NiO 4 cubes with good redox reactions with flower-like g-C 3 N 4 nanosheets, adding different amounts of g-C 3 N 4 nanosheets during the reaction can effectively improve their electrochemical performance. As expected, Ni/Co-5 %CN exhibits an excellent specific capacitance of 1701 F·g −1 at 1 A·g −1 when the CN addition is 5 %. Besides, constructed asymmetric supercapacitor (Ni/Co-5 %CN//AC ACS) showed a high energy density of 49.37 Wh·kg −1 . After 5000 cycles at 5 A·g −1 , it can achieve nearly 91.5 % capacitance retention rate. The results showed that Ni/Co-CN had great potential to build safe and high-performance energy storage devices. Here, we first used ZIF-67 as a precursor to successfully synthesize Co 2 NiO 4 with a hollow cubic structure. Then, using acidified thinner graphitized carbon nitride (g-C 3 N 4 ) for decorative design, a hollow Co 2 NiO 4 /g-C 3 N 4 (Ni/Co-CN) material with the appearance of flower-like nanosheets was prepared by the hydrothermal method. A perfect composite structure can exert a synergistic effect between materials, thereby improving their overall electrochemical performance. • The Ni/Co-CN material was synthesized through a simple hydrothermal process for excellent performance supercapacitors. • The prepared hollow Co 2 NiO 4 cubes derived from ZIF-67 were successfully decorated with flower-like g-C 3 N 4 nanosheets. • The Ni/Co-5 %CN has a superior specific capacitance of 1701 F g −1 at 1 A g −1 and better cycle stability. • The asymmetric supercapacitor shows an high energy density of 51.38 Wh kg −1 at the power density of 729.9 W kg −1 .

Improvement of electrochemical performance of titania nanowires for supercapacitor electrodes by in-situ growth of polyaniline nanoparticles

Supercapacitors with excellent electrochemical performance are considered the most promising candidates to meet the increasing energy demand. Herein, we developed a novel electrode material for supercapacitors, polyaniline (PANI)-3-aminopropyl triethoxysilane (APTEs)-titania nanowires (TNW), which was synthesized on potassium doped titanium foil via a simple two-step procedure. In the composite, the nano-mesh structure formed by APTEs-coated TNW serves as the framework for the growth of PANI nanoparticles, and PANI nanoparticles act as the electrochemically active part. The specific capacitance of PANI-APTEs-TNW of up to 315.16 mF cm −2 at 0.2 mA cm −2 in 1.0 M H 2 SO 4 solution is achieved, while that of PANI-TNW is 271.67 mF cm −2 . Meanwhile, the capacitance retention rate of PANI-APTEs-TNW is 86.8% after 1000 cycles under 1.5 mA cm −2 . Compared to PANI-TNW, the better capacitive behavior of PANI-APTEs-TNW is attributed to the anchoring effect of APTEs, which is highly interactive and exhibits compact structures between the TNW and PANI nanoparticles, resulting in a stable structure during the rapid charge-discharge process. This strategy is characterized by its good electrochemical properties, simple equipment, low cost of raw materials, and large-area preparation. Thus, our findings provide an effective method for the design of high-performance supercapacitors and promote their practical applications.

Electrochemical performance of CuCo2O4/CuS nanocomposite as a novel electrode material for supercapacitor

Electrochemical performance of CuCo2O4/CuS nanocomposite as a novel electrode material for supercapacitor

Direct chemical synthesis of interlaced NiMn-LDH nanosheets on LSTN perovskite decorated Ni foam for high-performance supercapacitors

Herein, we report a 3D hierarchical heterostructure LSTN@NiMn-layered double hydroxide (La0.4Sr0.4Ti0.9Ni0.1O3-δ@NiMn-LDH) as a novel electrode material for supercapacitors with outstanding performance. Designing the heterostructure with the wet chemical approach followed by the hydrothermal reaction to grow LDH layers has engineered LSTN@NiMn-LDH, a highly active towards the electrochemical performance. The formation of hybrid structure is characterized using X-ray diffraction, and scanning electron microscopy, which confirmed as well as showed the uniform growth of NiMn-LDH layers on LSTN nanoparticles. The electrochemical performance was studied by cyclic voltammetry and galvanostatic charge-discharge, representing the outstanding performance of the electrode materials. The capacity of LSTN@NiMn-LDH was found to be 485 mAh/g (1745 C/g) at 1 A/g, with 86% capacitive retention after 10,000 cycles at 2 A/g. The improved electrochemical performance of the LSTN@NiMn-LDH electrode could be ascribed to rapid diffusion pathways provided by LSTN and improved redox reactions of NiMn-LDH nanosheets owing to the high surface area.

Covalently bonded boron nitride quantum dot and reduced graphene oxide composite electrode for highly efficient supercapacitors

This study investigates the synthesis and application of boron nitride quantum dot (BNQD) covalently bonded reduced graphene oxide (rGO) hybrid materials as a novel electrode material for supercapacitors. Because of the p-doping as well as the enhanced hydrophilicity and interfacial bonding force enabled by the hybridization of amine-functionalized boron nitride quantum dot (A-BNQD) with rGO via the chemical coupling reaction, the A-BNQD/rGO shows improved charge carrier density, wettability of electrolyte, and durability. As a result of the synergistic effects, the A-BNQD/rGO as a supercapacitor electrode shows much higher specific capacitance compared to those of rGO and raw BNQD/rGO at a current density of 1 A g−1. Further, the A-BNQD/rGO shows high cycling stability, maintaining almost 94.38%, even after 10,000 cycles due to the enhanced interfacial bonding force between the A-BNQD and rGO. Besides, the fabricated symmetric supercapacitor exhibits high specific capacitance (90 F g−1@1 A g−1), an energy density (12.5 Wh kg−1@0.5 kW kg−1), and good cycling stability. This result suggested that the fabricated A-BNQD/rGO has great potential as electrode materials for high-performance supercapacitors.

Mesoporous CeO2-α-MnO2- reduced graphene oxide composite with ultra-high stability as a novel electrode material for supercapacitor

Mesoporous CeO2-α-MnO2-reduced graphene oxide (CeO2-α-MnO2-rGO) was prepared by hydrothermal method, which was further used as electrode material for supercapacitor. The electrochemical tests such as galvanostatic charge-discharge were carried out to explore the electrochemical performance of the as-prepared materials. The orthogonal test was designed to obtain the optimized experimental conditions. And the effect of CeO2 amount on the electrochemical performance of the composite was also considered. The electrochemical test showed that the specific capacitance of optimal CeO2-α-MnO2-rGO could reach 466 F g-1 at the current density of 1.0 A g-1 in 1.0 mol L-1 Na2SO4 solution, and the energy density and power density of CeO2-α-MnO2-rGO are 259 Wh kg-1 and 1008 W kg-1, respectively. After 10,000 cycles, the loss of specific capacitance was almost zero, indicating ultra-high cycle stability for CeO2-α-MnO2-rGO ternary composite. The results proved that CeO2-α-MnO2-rGO ternary composite is an excellent electrode material for supercapacitor.

CuMn2O4 spinel anchored on graphene nanosheets as a novel electrode material for supercapacitor

Copper manganese oxide-graphene (CuMn2O4-RGO) composite was prepared by sol-gel method and then synthesized by physical grinding, which was further applied to electrode materials for supercapacitors. The structure and morphology of the composites were analyzed by means of characterization, such as X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscope (SEM), transmission electron microscopic (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric (TG) analysis, and Raman. The electrochemical tests including cyclic voltammetry (CV), galvanostatic charge-discharge, electrochemical impedance spectroscopy (EIS) and cyclic life were used to investigate electrochemical properties of CuMn2O4-RGO so as to optimize its composition. Through the comparison of electrochemical properties at different mass ratios, current densities and scan rates, it was found that when the mass ratio was m (CuMn2O4): m (RGO) =1:1, the as-prepared CuMn2O4-RGO exhibited the excellent electrochemical properties. The capacitance reached 342 F g−1 at the current density of 1.0 A g−1, which was significantly higher than that of pure CuMn2O4 and RGO. The higher capacitance performance can be comparable with the reported literature value. Meanwhile, the energy density of CuMn2O4-RGO (1:1) is significantly higher than that of CuMn2O4 and RGO. Therefore, CuMn2O4-RGO (1:1) composite has a good prospect as electrode material for supercapacitor.

Emerging ternary nanocomposite of rGO draped palladium oxide/polypyrrole for high performance supercapacitors

In this work, novel electrodeposited palladium oxide-polypyrrole (PdP) and its ternary composite with reduced graphene oxide (PdPGO) draped over the surface of PdP were synthesised to achieve the excellent electrochemical properties and high stability. An exhaustive study has been carried out to correlate the crystalline structure, chemical bonding, morphological behaviour, redox reactions at the electroactive species, and its promising influences on the electrochemical performance. The electrodeposited PdPGO composite on stainless steel bestows superior electrochemical properties and a specific capacitance of 595 F g−1 at 1 A g−1 in 1 M H2SO4. The incorporation of rGO with the PdP matrix prevents the aggregation of rGO layers and is responsible for the enhanced electrostatic interactions at the electrode-electrolyte interface in PdPGO. Outstanding supercapacitance retention of 88% even after 5000 cycles at 5 A g−1 was accomplished for the ternary composite of Pd. These profound electrochemical characteristics are due to the synergistic effect of the individual components involved, manifest a great potential for Pd based composites toward novel electrode materials for supercapacitors of high efficiency. This method facilitates blueprints for synthesizing a series of advanced electrode materials for enhancing high storage capability. The high electrochemical performance of the PdPGO reveals how synergy plays a very important role to work on the blueprint to create active electrode materials for energy storage solutions.

Nickel cobalt manganese ternary carbonate hydroxide nanoflakes branched on cobalt carbonate hydroxide nanowire arrays as novel electrode material for supercapacitors with outstanding performance

In this work, for the first time we are reporting the development of a kind of high rate and long cycle life electrode composed of nickel cobalt manganese ternary carbonate hydroxide (NiCoMn-CH) ultrathin nanoflakes coated on Co-CH nanowire arrays (NWAs), which are directly generated on a nickel foam (NF) support. The hierarchical heterostructures are synthesized via a scalable two step solvothermal strategy without any adscititious surfactant and binder. The smart combination of Co-CH and NiCoMn-CH nanostructures in the nanowire arrays shows significant synergistic effect on the enhancement of the electrochemical performance of the as-fabricated supercapacitors. The as-obtained electrode exhibits excellent conductivity and high specific surface area, resulting in an unprecedented high specific capacitance (up to 3224F g−1 at 1 A g−1 in a three-electrode system) and an ultralong cycling stability (92.4% retention after 6000 successive charge–discharge cycles 5 A g−1). Meanwhile, an asymmetric supercapacitor device assembled of the Co-CH@NiCoMn-CH hierarchical nanostructures as positive electrode and activated carbon (AC) as negative electrode delivers good energy density of 20.31 W h kg−1 at the power density of 748.46 W kg−1 in the operation window 0–1.5 V. This methodology could be generalized to the design of other novel structured nanomaterials for energy storage devices and other applications.

Biomass Waste Derived Low Cost Activated Carbon from Carchorus Olitorius (Jute Fiber) as Sustainable and Novel Electrode Material

Abstract Natural bio mass derived active carbon from recycled jute is synthesized by simplistic hydrothermal approach and then chemically activated with KOH for further enhancement of electrochemical characteristics. The structural, chemical composition, morphological, and electrochemical measurements for jute carbon are explored in detail. The prepared active jute carbon exhibits high surface area of 1, 903.48 m2/g and high charge storage capacity with a specific capacitance of 346.00 F/g in 6 M KOH at a current density of 1.0 A/g; and shows excellent cyclic stability (the capacity retention ~96 %) over 10, 000 cycles, which authenticates excellent charge storage capacity of electrode material. Furthermore, a supercapacitor device is assembled by using jute carbon as both positive and negative electrode materials, which demonstrate the promising specific capacitance of 43.43 F/g in 1 M Na2SO4 at 0.5 A/g current density besides exhibits high specific energy of 15.44 Wh/kg at the specific power of 402.78 W/kg. Thus, from the explored results it can be concluded that, biomass derived active jute carbon could be used as a sustainable and novel electrode material for supercapacitors or batteries applications.

Rapid synthesis of bismuth molybdate nanoplates for supercapacitor applications by microwave combustion

Orthorhombic structured bismuth molybdate (Bi2MoO6) is obtained by one pot microwave combustion method. The characteristic performance of Bi2MoO6 nanocatalyst are described by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) furnished with Energy - dispersive X-ray spectroscopy (EDS) and Fourier change infrared (FT-IR) spectroscopy. The average crystallite size for Bi2MoO6 estimated from XRD is about 28.9 nm. The surface morphology from SEM pictures displays nanoplates. The FTIR is utilized to recognize the structural coordination and the presence of functional group. The electrochemical studies are taken to readily comprehend the electrochemical performance of the modified active electrode with notable specific capacitance value are found 234.9 Fg-1 at 5 mVs-1 and cyclic retention is stable up to 900 cycles (98.7 %). The as-synthesized dynamic material acts as a novel electrode material for supercapacitor.

One-step green route synthesis of spinel ZnMn2O4 nanoparticles decorated on MWCNTs as a novel electrode material for supercapacitor

This work focuses on designing new electrode materials by fabricating a nanocomposite hybrid of MWCNTs and a binary metal oxide, ZnMn2O4. The ZnMn2O4 has been extensively investigated as a high-performance anode in Li-ion battery, however, its capacitive faradaic charge storage behavior is rarely explored. Herein we demonstrate the fabrication of ZnMn2O4-CNT nanocomposites using acid modified MWCNTs and a one-step green hydrothermal method for supercapacitor application. The SEM analysis of the as-fabricated composites showed that the ZnMn2O4 nanoparticles were uniformly anchored on the MWCNTs backbone, which helps to maintain good electrical channel throughout the composite. Electrochemical characterizations were carried out in a three-electrode configuration in the 1 M Na2SO4 electrolyte in terms of cyclic voltammetry, galvanostatic charge discharge and electrochemical impedance spectroscopy analyses. The synergistic interaction between the MWCNTs and the ZnMn2O4 nanoparticles resulted in a high specific capacitance of 103 F/g of the as-fabricated electrode.

Homogeneous nickel metal-organic framework microspheres on reduced graphene oxide as novel electrode material for supercapacitors with outstanding performance

Herein, we designed and prepared nickel metal-organic framework microspheres anchored directly on reduced graphene oxide (Ni-MOF/rGO) by a facile hydrothermal and successive calcining process. The electrode for Ni-MOF/rGO composite annealed at an optimized temperature of 300 °C (Ni-MOF/rGO-300) shows desired conductivity, good cycling stability and high ion-accessible surface area, leading to an ultrahigh specific capacitance of 954 F g−1 at a current density of 1 A g−1 and a remarkable rate capability of 80.25% at 5 A g−1. Meanwhile, the assembled Ni-MOF/rGO-300//activated carbon asymmetric supercapacitor (ASC) shows a favorable energy density up to 17.13 Wh kg−1 at a power density of 750 W kg−1 in the potential window of 0–1.5 V. Moreover, the capacitance retention can still maintain 81.63% after 4000 cycles at a high current density of 5 A g−1. The excellent electrochemical properties can be credited to the synergistic effects between the unique structures of Ni-MOF and rGO, which makes the Ni-MOF/rGO composite a potential electrode material for high performance supercapacitors.

Quantum dots of molybdenum nitride embedded in continuously distributed polyaniline as novel electrode material for supercapacitor

Molybdenum nitride (Mo2N) and molybdenum nitride/polyaniline composites (Mo2N@PANI) have been prepared by simple static precipitation and in situ growth methods. The morphological and structural properties and chemical composition of the prepared materials have been analyzed by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The obtained results illustrate that in molybdenum nitride/polyaniline composites, polyaniline has been allocate continuously embedded with the quantum dots of molybdenum. Therefore, the formation of quantum dots of molybdenum and its uniform distribution in polyaniline bulk suggested that the synthesized materials could be used as an electrode material of supercapacitors. From the results of electrochemical analysis, the mass ratio capacitance of molybdenum nitride/polyaniline composites have been found to be 111.8 F/g at 0.5 A/g, while the mass ratio capacitance of pure molybdenum nitride is only 47.5 F/g at the same current density. Hence, obtained results clearly confirm that molybdenum nitride/polyaniline composites nanostructured quantum dot material is one of the best and novel electrode materials for high performed supercapacitors which exhibits excellent electrochemical properties.

Hierarchically mesoporous micro/nanostructured CoP nanowire electrodes for enhanced performance supercapacitors

The development of effective and high capacitive electrode materials for supercapacitor applications is highly desired. CoP nanowires are prepared by hydrothermal-oxidation-phosphidation method. As a novel electrode material for supercapacitors operating in alkaline aqueous electrolyte, the CoP nanowire electrode exhibits relatively high specific capacitance of 558 F g−1 at a current density of 1 A g−1, maintains a stable cycling life with 98% of the initial capacitance after continuous 5000 cycles. Furthermore, the CoP nanowire electrode can reach up to a high energy density of 23.4 W h Kg−1 at a power density of 274 W Kg−1. Moreover, it is found that as-prepared CoP nanowire electrode delivers substantially enhanced specific capacitance and rate performance compared with the Co3O4 nanowire electrode. These results demonstrate that the CoP nanowires could be an attractive electrode material for high-performance supercapacitor applications.