Electrode Materials For Supercapacitors Research Articles

Nickel-copper-cobalt mixed oxide electrode material for high performance asymmetric supercapacitor

Nickel copper cobalt oxide (NiCuCoO) ternary metal oxide nanoparticles were synthesized by employing the hydrothermal method. NiCuCoO electrode demonstrates a specified capacity of 596 C g−1 at 1 A g−1, high capacitance retaining of 99% even if 1000 sequences at the density of current 10 A g−1, and significant extended cyclic strength over 1000 sequences. The gathered asymmetric supercapacitor (ASC) tool via NiCuCoO as the cathode and activated carbon as anode materials achieve a specified capacity of 168 C g−1 at a current density of 1 Ag−1, an excellent capacity retaining of 95% even later than 5000 sequences at a density of current 10 A g−1. The fabricated device exhibits a high density of energy and power is 96 Wh kg−1 and 841 W kg−1. The prepared material confirms an excellent capacitance routine, so this work represents for a next-generation energy storage device.

Hydrothermal formation of novel SrCeO3/RGO nanocomposite as supercapacitor electrode material

Hydrothermal formation of novel SrCeO3/RGO nanocomposite as supercapacitor electrode material

Synergistic Enhancement of Supercapacitors with Cobalt‐Copper Bimetal–Organic Framework

Metal‐organic frameworks (MOFs), as high‐potential electrode materials for applications in supercapacitors, have received significant attention recently. Unfortunately, MOF materials still suffer from unsatisfactory specific capacitances due to poor conductivity and limited redox active sites. In this work, a novel cobalt‐copper‐based bimetal–organic framework (CoCu‐MOF) was synthesized by a bottom‐up synthesis strategy, the material properties systematically characterized, and finally investigated as a supercapacitor electrode material. The synthesized CoCu‐MOF presented a high specific surface area of 62.4 m2 g−1, and 83% of the copper ions attained the +1 oxidation state contributing to the formation of additional redox active sites and leading to the formation of dual‐redox sites. The CoCu‐MOF displayed an excellent specific capacitance of 618 F g−1 at a current density of 1 A g−1, which was more than twice that of Co‐MOF and four times that of Cu‐MOF. The CoCu‐MOF retained 75% of its original capacitance after 3000 charge‐discharge cycles at the current density of 1 A g−1. Overall, this work demonstrates how the bimetallic synergistic strategy can effectively enhance the electrochemical properties of MOFs by providing a higher specific surface area and by the introduction of dual redox sites.This article is protected by copyright. All rights reserved.

Fabrication of Ternary Titanium Dioxide/Polypyrrole/Phosphorene Nanocomposite for Supercapacitor Electrode Applications

In this paper, we report a titanium dioxide/polypyrrole/phosphorene (TiO2/PPy/phosphorene) nanocomposite as an active material for supercapacitor electrodes. Black phosphorus (BP) was fabricated by ball milling to induce a phase transition from red phosphorus, and urea-functionalized phosphorene (urea-FP) was obtained by urea-assisted ball milling of BP, followed by sonication. TiO2/PPy/phosphorene nanocomposites can be prepared via chemical oxidative polymerization, which has the advantage of mass production for a one-pot synthesis. The specific capacitance of the ternary nanocomposite was 502.6 F g−1, which was higher than those of the phosphorene/PPy (286.25 F g−1) and TiO2/PPy (150 F g−1) nanocomposites. The PPy fully wrapped around the urea-FP substrate provides an electron transport pathway, resulting in the enhanced electrical conductivity of phosphorene. Furthermore, the assistance of anatase TiO2 nanoparticles enhanced the structural stability and also improved the specific capacitance of the phosphorene. To the best of our knowledge, this is the first report on the potential of phosphorene hybridized with conducting polymers and metal oxides for practical supercapacitor applications.

Highly stable TiO2/g-C3N4 composite electrodes for quasi-solid-state supercapacitor applications

Supercapacitor research focuses on cheap, long-lasting electrode materials. As a semiconductor, titanium dioxide (TiO2) is cheap and chemically stable, making it a promising electrode material for supercapacitors. The goal is to improve carbon-based composites by hybridizing conductive materials. The graphitic carbon nitride (g-C3N4) is a stable and common allotrope of C3N4. Its optical, electrical, and structural properties make it a good hybrid system for supercapacitors. With a simple, affordable, and successful thermal decomposition method, we synthesized a TiO2/g-C3N4 composite material. Supercapacitors have 20.6 F g−1 specific capacitance, 63 Wh kg−1 energy density, and 92 % Coulombic efficiency. The TiO2/g-C3N4 composite showed highly stable electrochemical performance even after 10,000 charge–discharge cycles.

A rigid free-standing supercapacitor electrode material made from fat coal-based activated carbon foam

A free-standing electrode material is a competitive candidate for supercapacitor due to its excellent capacity and volumetric energy density. Currently, most of the studies are focused on the preparations and performances of flexible free-standing electrode materials, whereas few on the development of rigid free-standing electrode materials. Herein, a vitrinite concentrate of fat coal is used as a raw material and carbon black as an addition agent to prepare a carbon foam by way of high-pressure pyrolysis. The prepared carbon foam is activated by KOH solution to further achieve an activated carbon foam by which we have fabricated a rigid free-standing electrode material. The assembled symmetric device with the rigid free-standing electrode material demonstrates an extremely high areal specific capacitance of 2304.41 mF cm−2 at 4 mA cm−2, an outstanding cycling stability of 100 % after 40 000 cycles, and an excellent volume energy density of 10.23 mWh cm−3 at 31.78 mW cm−3. These fascinating electrochemical performances of the electrode material are attributed to unique 3D interconnected porous structure of the activated carbon foam. The micron-sized 3D interconnected pores facilitate the transport of electrolyte ions within the electrodes. Meanwhile, micropores on the 3D interconnected pore wall provide abundant active sites for electrolyte ions.

Long cycle life achieved in polyaniline/SP based self-healing supercapacitor

Polyaniline (PANI) has emerged as a promising electrode material for supercapacitors due to its low cost and high specific capacitance. However, during the charge and discharge process, PANI undergoes volume changes, leading to structural damage at the molecular level. This results in material pulverization, causing a loss of electronic contact with the electrode and, consequently, a decrease in capacitance. In this study, we employed ultrasonication-assisted growth of PANI on super-P (PANI/SP-US) to enhance the structural stability. At 1 A g−1, a high specific capacitance of 639 F g−1 was achieved. After 5000 charge-discharge cycles at 2 A g−1, the material retained 75.9% of its capacitance. More importantly, we further developed an effective strategy to incorporate a self-healing polymer (SHP) to fabricate a self-healing electrode. Due to the self-healing ability, the pulverized PANI/SP-US was able to be reconnected and restore electronic contact with the electrode substrate, thereby regaining specific capacitance and achieving excellent cycle life. The sphere-like shape of PANI/SP-US is also of benefit to the self-healing process. Symmetric and asymmetric self-healing devices based on PANI/SP-US and the self-healing polymer exhibited outstanding cyclic stability, retaining 107.9% and 108% of their capacitance, respectively, after 10,000 cycles at 2 A g−1. The self-healing device also exhibits good flexibility under bending, folding deformations. In addition, the device also shows good capacitance retention as the temperature shifted from 50°C to 0°C. This work underscores the significance of microstructure self-repair in enhancing cyclic stability and extends the application of self-healing devices to flexible and variable-temperature conditions.

Preparation of Positive and Negative Composite Electrode Materials for High-Performance Aqueous Asymmetric Supercapacitor by a Sequential Two-Step Reaction

Preparation of Positive and Negative Composite Electrode Materials for High-Performance Aqueous Asymmetric Supercapacitor by a Sequential Two-Step Reaction

High Volumetric Energy Density Supercapacitor of Additive-Free Quantum Dot Hierarchical Nanopore Structure.

The high surface-area-to-volume ratio of colloidal quantum dots (QDs) positions them as promising materials for high-performance supercapacitor electrodes. However, the challenge lies in achieving a highly accessible surface area, while maintaining good electrical conductivity. An efficient supercapacitor demands a dense yet highly porous structure that facilitates efficient ion-surface interactions and supports fast charge mobility. Here we demonstrate the successful development of additive-free ultrahigh energy density electric double-layer capacitors based on quantum dot hierarchical nanopore (QDHN) structures. Lead sulfide QDs are assembled into QDHN structures that strike a balance between electrical conductivity and efficient ion diffusion by employing meticulous control over inter-QD distances without any additives. Using ionic liquid as the electrolyte, the high-voltage ultrathin-film microsupercapacitors achieve a remarkable combination of volumetric energy density (95.6 mWh cm-3) and power density (13.5 W cm-3). This achievement is attributed to the intrinsic capability of QDHN structures to accumulate charge carriers efficiently. These findings introduce innovative concepts for leveraging colloidal nanomaterials in the advancement of high-performance energy storage devices.

Synergistic effects in CuO/SnO2/Ti3C2Tx nanohybrids: Unveiling their potential as supercapacitor cathode material

In the field of materials science, a synergistic effect occurs when the combined physical and chemical properties of a composite material show significant improvement compared to the properties of its individual components. In this study, we synthesized a novel nanosheet-like structure composed of copper oxide (CuO) and tin oxide (SnO2) dispersed on MXene (Ti3C2Tx) sheets using an ultrasonicated coprecipitation method, and then we explored its synergistic effects. The CuO/SnO2/MXene nanohybrids were characterized through SEM, HRTEM, XRD, XPS, and BET analysis, confirming successful synthesis and evident synergy between MXene and CuO/SnO2. The electrochemical behaviour of the nanohybrid structure was investigated using different electrochemical techniques. CuO/SnO2/MXene revealed a high capacitance of 683.5 Fg-1 at 1 Ag-1 in a 2 M H2SO4 electrolyte, with 85 % cycling performance after 10,000 cycles. Notably, this performance surpassed that of MXene-Ti3C2Tx and CuO/SnO2 separately, which achieved only 102.8 and 378.2 Fg-1 capacitance with 60 % and 76 % cycling stability, respectively. These incredible results are attributed to CuO/SnO2/MXene nanohybrids' synergistic effects, whereby enhance the surface area, electrical conductivity, and availability of active sites and enhanced electrochemical performance. This research offers a promising solution for advancing supercapacitor electrode materials through the creation of a novel nanosheet structure that leverages synergistic effects.

Exploring the Potential of Nitrogen-Doped Graphene in ZnSe-TiO2 Composite Materials for Supercapacitor Electrode.

The current study explores the prospective of a nitrogen-doped graphene (NG) incorporated into ZnSe-TiO2 composites via hydrothermal method for supercapacitor electrodes. Structural, morphological, and electronic characterizations are conducted using XRD, SEM, Raman, and UV analyses. The electrochemical study is performed and galvanostatic charge-discharge (GCD) and cyclic voltammetry (CV) are evaluated for the supercapacitor electrode material. Results demonstrate improved performance in the ZnSe-NG-TiO2 composite, indicating its potential for advanced supercapacitors with enhanced efficiency, stability, and power density. Specific capacity calculations and galvanic charge-discharge experiments confirmed the promising electrochemical activity of ZnSe-NG-TiO2, which has a specific capacity of 222 C/g. The negative link among specific capacity and current density demonstrated the composite's potential for high energy density and high-power density electrochemical devices. Overall, the study shows that composite materials derived from multiple families can synergistically improve electrode characteristics for advanced energy storage applications.

Unraveling lithium-ion intercalation in lead-free bismuth-based vacancy ordered halide perovskites supercapacitors

Halide perovskites have recently gained a lot of attention in energy storage applications because of their unique properties. The difficulty in getting high-performance supercapacitors requires the significant development and customization of electrode materials. This study explores vacancy-ordered lead-free halide perovskites with chemical formula A3B2X9 as electrode material for supercapacitors. Furthermore, we have tuned the X site (X = Br−, Cl−, I−) to see the effect of halide ions on supercapacitor performance. Due to high ionic mobility and BET surface area, Cs3Bi2I9 has a specific capacitance of ∼242 F/g and energy density of ∼140 Wh/kg; however, power density variation is almost the same for all samples, measured in three-electrode systems. We have performed the ex-situ XRD and FTIR to understand the structural changes before and after charging. XPS measurement shows the peak shifting before and after measurement in Lithium-based electrolytes. Further, we have fabricated double perovskite-based symmetric devices with gel electrolyte as a separator. The Cs3Bi2I9 device shows an areal energy density of ∼23 μWh/cm2, the highest among all halide perovskite-based supercapacitor devices reported to date. The flexible device on the S.S. substrate shows 79% and 82% capacitance retention up to 180° bending angle and 200 bending cycles, respectively.

Production and applications of lead (II) oxide/poly(aniline-co-thiophene) composite materials for enhanced supercapacitor performance

In this work, a novel approach was employed to prepare and utilize lead (II) oxide and poly(aniline-co-thiophene) (PANI-co-PTh) composite materials as electrode materials for supercapacitors, marking the first instance of such utilization in the literature. PANI-co-PTh was synthesized in bulk through chemical polymerization, and the conducting polymers underwent comprehensive spectroscopic, physical, and microscopic characterization. Subsequently, the material, incorporating lead (II) oxide (PbO) as a composite, was employed as electrode materials in asymmetric-type supercapacitors. The main results indicate a clear relationship between the surface area of conducting polymers and their specific capacitance. Notably, PANI-co-PTh-6, possessing the highest surface area, demonstrated the highest specific capacitance. Particle size distribution and specific surface area for PANI-co-PTh-6 were determined as 130 μm and 64.76 m2g−1, respectively. The PbO@PANI-co-PTh-3 configuration exhibited the highest specific capacitance, reaching 294 Fg−1 at a 10 mVs−1 scan rate. Remarkably, during long-cycle experiments, this system demonstrated a capacity retention of 70.69% after 1000 cycles. The inaugural application of the PbO@PANI-co-PTh-3 supercapacitor showcased notable capacitance values, establishing a substantial foundation for future research endeavors in this field.

Optimization of Cobalt-Based MOFs for Super-Capacitor Electrode Materials of New Energy Vehicle

Super-capacitors (SCs), as new energy conversion storage elements, have attracted much attention, but there is still a research gap in the design of electrode materials. In this study, the optimization scheme of Metal-Organic Frameworks (MOFs) and cobalt-based MOF composites as electrode materials for SCs in new energy vehicles is explored, and a series of experiments are conducted to evaluate their performance. Scanning Electron Microscope (SEM) images reveal that the cobalt-based MOF composites have a surface morphology of particles with uniform distribution. The electrochemical performance test results show that the specific capacitance of the cobalt-based MOF composites is much higher than the sum of the two individual electrode materials and presents a remarkable increase with the scanning rate. Additionally, in the constant current charge-discharge test, cobalt-based MOF composites exhibit the longest charge-discharge time and good symmetry. Electrolyte particle contact tests for samples at different preparation temperatures display that high-temperature samples have better structural stability and electrolyte ion contact. In Cyclic Voltammetry (CV) and Galvanostatic Charge Discharge (GCD) tests, the 250°C sample demonstrates the best electrochemical properties and the highest specific capacitance (269 F/g). Moreover, as the current density increases, the specific capacitance of the 600°C sample decreases at a lower rate, showing stronger stability. However, the use of cobalt-based MOF materials may pose environmental and safety risks, such as the environmental impact of cobalt resource mining, instability under high-temperature conditions, and the possible production of hazardous substances. Therefore, these factors need to be fully considered when designing and using SCs to ensure the environmental friendliness and safety of cobalt-based MOFs. These results provide an important reference for selecting and optimizing electrode materials for SCs in new energy vehicles. Furthermore, this study offers research suggestions for improving new energy materials, filling the research gaps in related fields, and supporting the further development of SC technology.

In-situ synthesis of coral reef-like synergistic zinc cobalt oxide and zinc manganese oxide composite as a battery-type electrode material for supercapacitors

Recently, in-situ preparation of metal oxide composite structures has gained much importance in fabricating electrode materials for energy storage and conversion devices because of its advantageous properties of beneficial interfacial contact, high conductivity, good synergism, short ion diffusion distance, better electrochemical performance, etc. Binary transition metal oxides (BTMOs) are given great attention for their significant electrochemical performances over primary MOs because of the two metal ions with different valent states for the redox reactions. In this study, we synthesize zinc cobalt oxide (ZnCo2O4) and zinc manganese oxide (ZnMn2O4) composite via a solvothermal synthetic method. The existence of both phases is identified using an X-ray diffraction analysis (XRD). The unique coral reef-like structures of the composite electrode are analysed via field emission scanning electron microscopy, and the nanostructure was identified using transmission electron microscopy. The X-ray photoelectron spectroscopy confirms the surface oxidation states of the composite and supports the XRD analysis. The synergetic composite electrode provides a large surface area of 50.86 m2 g-1 with many pores. The composite electrode has a specific capacity of 250Cg-1 at 1Ag-1. The ZCO/ZMO composite demonstrated impressive stability, retaining a specific capacity of 180Cg-1 at 6Ag-1 over 5000 cycles.

Highly conductive titanium nitride core sterically reinforced nickel-vanadium layered double hydroxides for supercapacitors

Nickel vanadium layered double hydroxide (NiV-LDH) is a highly promising electrode material for supercapacitors, but its poor electrochemical durability and conductivity limit its capacitance performance as a high-performance supercapacitor electrode. In contrast, titanium nitride (TiN) stands out for its outstanding electrochemical durability and superior conductivity. In this work, a composite material (TiN@NiV-LDH) with outstanding electrochemical performance was prepared by a simple hydrothermal method, where nickel vanadium layered double hydroxide nanosheets were vertically grown in a staggered manner on the surface of amorphous titanium nitride nanoparticles. The results demonstrate that at a current density of 2 A g-1, the capacitance of TiN@NiV-LDH reaches 712.4 F g-1. In addition, the assembled TiN@NiV-LDH//AC asymmetric supercapacitor exhibits a high energy density of 136.5 Wh kg-1 at a high power density of 1549.9 W kg-1, and after 10000 cycles at a high current density of 20 A g-1, it retains 80.2% excellent cyclic stability. This work, based on nickel vanadium layered double hydroxide and utilizing titanium nitride modification, aims to enhance the long-term stability of nickel vanadium layered double hydroxide while preserving its advantageous properties, providing a promising strategy for designing efficient supercapacitor electrodes.

Sandwich-like high-performance Ti3C2Tx MXene/NiCo2O4 nanosphere composites for asymmetric supercapacitor application

NiCo2O4 is a promising electrode material for supercapacitors due to its low cost, high theoretical specific capacitance and good cycling stability. However, NiCo2O4 has the disadvantages of poor electronic and ionic conductivities and easy agglomeration. Moreover, the irreversible structural damage caused by the NiCo2O4 volume expansions during charging and discharging limits its use in supercapacitors. Herein, we fabricated sandwich Ti3C2Tx MXene/NiCo2O4 composites via an electrostatic self-assembly method. The problem of easy agglomeration of the NiCo2O4 nanospheres was solved by intercalating Ti3C2Tx MXene layers with the NiCo2O4 nanospheres. Furthermore, the Ti3C2Tx MXene layer was also utilized as a protective layer to limit serious volume expansion and protect the structure of NiCo2O4 nanospheres from destruction. The results showed that the prepared Ti3C2Tx MXene/NiCo2O4 composite exhibited a high specific capacitance of 1025 F g−1 at a current density of 1 A g−1 and had an initial capacity of 81 % when the current density was increased to 10 A g−1. The Ti3C2Tx MXene/NiCo2O4 composite cathode and activated carbon anode were assembled in an asymmetric supercapacitor, which showed an energy density of 36.67 Wh kg−1 at 800 W kg−1 and a capacity retention of 88.2 % after 5000 cycles.

Nickel-cobalt-chromium ternary transition metal hydroxide for supercapacitors

Metal hydroxide is a promising electrode material for supercapacitors. And third metal introduction can improve its electrochemical performance. In this paper, the Cr was introducing into NiCo-LDH by one-step hydrothermal method. In addition, the influence of Cr content on the electrochemical performance was investigated. The results show that maximum specific capacitance of 2712 F g-1 with the ratio of Ni: Co: Cr of 1:1:0.05, higher than pure NiCo-LDH of 1676 F g-1. In addition, the assembled NiCoCr-0.05//YP50 supercapacitor devices can reach an energy density of 27.38 Wh kg-1 with a good cycle life.

Magnetic field-assisted electrodeposition of ZnCo2O4-rGo nanoelectrodes for enhanced supercapacitor performance

To investigate a convenient, rapid, and environmentally friendly method for the preparation of supercapacitor electrode materials to enhance supercapacitor performance, this study achieved the successful synthesis of ZnCo2O4-rGo (ZCG) nanomaterial electrodes on a nickel foam substrate. These electrodes were then assembled into supercapacitors using Magnetic field-assisted Electrodeposition (MFAED) technology. The surface morphology and structure characterization analysis revealed that the ZCG-4 material exhibited a mesoporous layered nanosheet structure. Moreover, they exhibited a significant specific active surface area of 155.7 m2/g and showed excellent adhesion to the nickel foam substrate. The electrochemical properties of the ZCG nanoelectrode material were studied in a 1 M KOH aqueous solution. The results revealed that the ZCG-4 nanoelectrode displayed low electrochemical impedance (Rs 0.23 Ω, Rct 1.36 Ω, and Zw 0.99 Ω) and a high specific capacitance of 2672 Fg−1. Furthermore, at a current density of 3 Ag−1, the electrode maintained good capacity retention (2672 Fg−1–2529 Fg−1, 94.6 %). Moreover, it retained a significantly high specific capacitance of 1339 Fg−1 even after 6000 cycles under a current density of 20 Ag−1. The supercapacitor assembled with ZCG-4 electrodes exhibits good electrochemical performance, possessing a high capacitance of 5.8F/cm2 at a current density of 1 mA/cm2. Moreover, the ZCG-4 supercapacitor demonstrates outstanding cyclic performance, maintaining 86 % capacity retention following 6000 charge–discharge cycles at a high current density of 30 mA/cm2. The mechanism of magnetic field electrodeposition for preparing ZCG has also been explained using magnetohydrodynamics theory. At a magnetic field strength of 6 T, the ion migration speed is 1.7 × 10−5 m/s, and the addition of the magnetic field effectively increases this speed. An effective magnetic field electrodeposition approach was thus proposed in this investigation to enable the synthesis of high-performance electrode materials and capacitors by combining metal oxide and rGo.

MoO3/WO3/rGO as electrode material for supercapacitor and catalyst for methanol and ethanol electrooxidation.

The potential of metal oxides in electrochemical energy storage encouraged our research team to synthesize molybdenum oxide/tungsten oxide nanocomposites (MoO3/WO3) and their hybrid with reduced graphene oxide (rGO), in the form of MoO3/WO3/rGO as a substrate with relatively good electrical conductivity and suitable electrochemical active surface. In this context, we presented the electrochemical behavior of these nanocomposites as an electrode for supercapacitors and as a catalyst in the oxidation process of methanol/ethanol. Our engineered samples were characterized by X-ray diffraction pattern and scanning electron microscopy. As a result, MoO3/WO3 and MoO3/WO3/rGO indicated specific capacitances of 452 and 583 F/g and stability of 88.9% and 92.6% after 2000 consecutive GCD cycles, respectively. Also, MoO3/WO3 and MoO3/WO3/rGO nanocatalysts showed oxidation current densities of 117 and 170 mA/cm2 at scan rate of 50 mV/s, and stability of 71 and 89%, respectively in chronoamperometry analysis, in the MOR process. Interestingly, in the ethanol oxidation process, corresponding oxidation current densities of 42 and 106 mA/cm2 and stability values of 70 and 82% were achieved. MoO3/WO3 and MoO3/WO3/rGO can be attractive options paving the way for prospective alcohol-based fuel cells.