Asymmetric Supercapacitor Applications Research Articles

Sphere-like Naphthalene-Based Microporous Nickel Phosphonate Facile for Asymmetric Supercapacitor Devices and Bifunctional Oxygen Electrocatalysts

To produce clean energy due to the lack of fossil fuels, the development of cost-effective and highly efficient energy storage devices and multifunctional electrocatalysts is essential to substitute noble metal-based electrocatalysts. In this context, transition metal-based nickel phosphonate material (NiNAP) has been synthesized using 1,1′-binaphthyl-2,2′-diyl hydrogenphosphate and nickel nitrate hexahydrate in a hydrothermal reaction pathway in the absence of a templating pathway. The organic–inorganic hybrid structure with microporous arrays as a potential electrode material facilitates energy storage and conversion reactions. For the first time, a sphere-like NiNAP material has been developed, which is a potential electrode material for asymmetric supercapacitor applications with high specific capacitance and both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) with a low overpotential and higher current density. Moreover, the NiNAP material exhibits a specific capacitance of 4456 F g–1 in three-electrode assembly and 455 F g–1 in asymmetric supercapacitor at a scan rate of 1 mV s–1, where the energy and power density are estimated to be 204 W h kg–1 and 409 W kg–1, respectively. Interestingly, the NiNAP material displays outstanding catalytic activity toward OER with a low overpotential of 242 mV at the current density of 10 mA cm–2 and excellent ORR activity with an onset potential of 0.74 V vs RHE. Also, it shows long-term stability without significant changes in the current density for OER and ORR.

Electrochemical Characteristics of Polyaniline Nanofibers and Active Chromium Sulfide Nanoparticles for Asymmetric Supercapacitor Applications

AbstractMetal sulfides exhibit rich surface chemistry and electrochemical features and their comparison with polyaniline may give a new perspective to supercapacitor applications. Active chromium sulfide nanoparticles and polyaniline nanofibers were synthesized using the solvothermal and polymerization process, respectively. Chromium sulfide nanoparticles reveal a good specific capacitance of 594.38 F/g at the current density of 1 mA/cm2, meanwhile, the polyaniline nanofibers exhibit a maximum specific capacitance of 150 F/g at the current density of 4 mA/cm2, through the galvanostatic charge‐discharge profile. The power density of the polyaniline was found 3111 W/Kg, which is greater due to the conductive nature of polyaniline, meanwhile, chromium sulfide nanoparticles also exhibit a reasonable power density of 2403.06 W/Kg. Comparatively, chromium sulfide nanoparticles maintained specific capacitance and power density. The two electrodes asymmetric system exhibits a good coulomb efficiency of 100 % at 1 mA/cm2. So, chromium sulfide nanoparticles exhibit good electrochemical characteristics for supercapacitor applications.

Facile synthesis of mesoporous MnCo2O4@MoS2 nanocomposites for asymmetric supercapacitor application with excellent prolonged cycling stability

A synergistic effect occurs in material science when a composite material's physical and chemical properties increase significantly as compared to its individual components. In the present work, MnCo2O4 (MCO) and MnCo2O4@MoS2 (MCOS) nanocomposites have been synthesized using the co-precipitation synthesis process. The main focus of the present research is to observe the impact of MoS2 on the electrochemical characteristics of the nanocomposites while keeping the MCO precursor quantity constant. The MCOS nanocomposite was synthesized with a homogeneous dispersion of 20 % MoS2 (MCOS20). It has the most significant enhancement in electrochemical properties due to its larger specific surface area (44 m2g−1) and mesoporous distribution of pore size. The MCOS20 nanocomposite as a single electrode possesses larger specific capacitances of 512 F g−1 at 0.5 A g−1 and exhibits a good rate capability. Besides that, the electrode exhibits excellent cycling stability of 91.87 % along with the coulombic efficiency of 99.57 % up to 5000 consecutive cycles, even at a high current density of 8 A g−1. An asymmetric supercapacitor (ASC) device has been fabricated with the MCOS20 nanocomposite as a cathode and commercially purchased activated carbon as an anode electrode to examine the practical utility of synthesized composite material. The device displays the highest specific energy density and power density of 36 Wh kg−1 and 19 kW kg−1, respectively. The device shows excellent stability up to 20,000 cycles at 3.5 A g−1 with a coulombic efficiency of 98.85 % and capacitance retention of 94.28 % in 6 M KOH gel electrolyte. Furthermore, the two devices illuminate red, blue, and yellow LEDs. It lights up for more than 3 min a red LED. We believe that our proposed MCOS20 nanocomposite has potential for use as electrodes in the fabrication of high-performance supercapacitor devices, owing to its simple manufacturing method and good electrochemical performance.

In situ synthesis of a non-toxic cobalt–benzimidazole metal–organic framework decorated reduced graphene oxide composite for asymmetric supercapacitor applications

Synthesis of non-toxic cobalt-benzimidazole metal–organic framework decorated reduced graphene oxide composite for asymmetric supercapacitor applications.

Surfactant assisted synthesis of strontium hexaferrite microspheres for the fabrication of high-performance asymmetric supercapacitors

Synthesis of magnetic strontium hexaferrite particles by a chemical co-precipitation method for asymmetric supercapacitor applications.

Deoxyribonucleic acid scaffold assisted structural engineering to tune the intrinsic to extrinsic capacitive behavior in spinel structured MnCo2O4.5 for high-performance asymmetric supercapacitor application

The spinel structured materials (e.g., MnCo2O4.5) are good aspirants for supercapacitor electrode application due to their outstanding pseudocapacitor performance. However, due to the collapsing of the crystal and morphological structures during electrochemical analysis, inferior cyclic stability and low energy density problems are inevitable when the materials are used as supercapacitor electrodes. Alteration of intrinsic (diffusion-controlled) to extrinsic (surface-controlled) capacitive behavior is the effective solution to overcome these issues. Herein, the intrinsic capacitor behavior of the MnCo2O4.5 material was altered into an extrinsic mechanism through the precipitation process with the aid of a deoxyribonucleic acid (DNA)-based structural engineering process. The MnCo2O4.5 coated on nickel foam current collector delivered the specific capacity of 649C g−1 at 1 A g−1 and retained 97 % of its initial capacity after 5000 cycles at 20 A g−1 in three-electrode configurations. Additionally, the MnCo2O4.5//Activated carbon asymmetric device showed a specific capacity of 93.8C g−1 at 1 A g−1 with energy and power densities of 33.4 Wh Kg−1 and 681 W Kg−1 at 1 A g−1, respectively. DNA-based structural engineering demonstrates the tuning of intrinsic to extrinsic capacitive behavior resulting in better supercapacitor properties in MnCo2O4.5 material.

Nanometric MnO2 and MnO2‐Graphene Oxide Materials Enabled by a Solvent‐Assisted Synthesis and Their Application in Asymmetric Supercapacitors

Conventional manganese oxide (MnO2)‐based supercapacitors struggle to achieve theoretical capacitance due to the material's low conductivity and large particle size. Consequently, researchers have improved MnO2's properties by incorporating conductive carbonaceous materials to obtain high‐performance composite materials. Herein, the full process of engineering a MnO2‐graphene oxide (GO) composite and its application as a positive electrode for asymmetric supercapacitors (ASC) is presented. First, GO using a novel gas expansion precursor allowing an efficient chemical exfoliation of pristine graphite is synthesized. Afterward, size‐weakened MnO2 nanoparticles are synthesized and deposited onto the GO sheets by a self‐assembly redox reaction method using different MnO2/GO mass ratios. Multiple characterization methods are used to investigate the textural and structural properties of each material. A general electrochemical characterization is conducted using a three‐electrode cell; therefore, the synthesized MnO2‐GO composite achieves 150 F g−1 at 10 mV s−1. Furthermore, an ASC in an aqueous electrolyte using GO and MnO2 or MnO2‐GO as negative and positive electrodes, respectively, is assembled. The fabricated ASC based on MnO2‐GO composite exhibits a high specific capacitance of 38 F g−1 at 1 A g−1, excellent cycling stability after 36 000 cycles, and a steady electrochemical impedance behavior after 120 h of floating.

Three-dimensional network structured MnCo2S4/NiCo2S4 electrode materials assembled with two-dimensional nanosheets as basic building units for asymmetric supercapacitor applications

Recently, the construction of morphology and structure is considered to be one of the key factors to improve the cycle stability and rate performance of nanomaterials. Herein, MnCo2S4/NiCo2S4 (MCS/NCS) composites with three-dimensional network structures were fabricated by simple electrodeposition of NiCo2S4 nanosheets on the MnCo2S4 nanosheets framework. Compared with the two-dimensional nanosheet structure, the three-dimensional network structure of MCS/NCS has good capacitive and conductive properties. Also, the effects of electrodeposition time on the morphology and electrochemical properties of the composites were studied. Among them, MCS/NCS-6 stands out for its unique structure and excellent electrochemical properties, exhibiting excellent specific capacity (920 C g−1 at a current density of 1 A g−1) and good cycling stability. More importantly, the fabricated asymmetric supercapacitor MCS/NCS//AC assembly has a high energy density of 45.6 Wh kg−1 (800 W kg−1 power density) and good cycle life (75.6%, 10,000 cycles), demonstrating the potential application of this uniquely structured electrode material in alkaline aqueous energy storage devices such as asymmetric supercapacitors (ASC).

Size-controllable synthesis of covalently interconnected few-shelled Fe3O4@onion-like carbons for high-performance asymmetric supercapacitors

Fe3O4 is considered as an appealing anode material for constructing high-energy-density asymmetric supercapacitors owing to its high theoretical capacitance, large potential window, natural abundance and eco-friendliness. However, the dilemma of inadequate practical capacitance, low rate performance and unsatisfactory cycling stability of Fe3O4-based electrode materials significantly plagues their progress in supercapacitor applications. To well utilize the advantage of Fe3O4, herein, Fe3O4@onion-like carbons (OLCs) with covalently interconnected and few-shelled graphitic coatings were synthesized in a size-controllable manner from uniform-sized monodispersed nanoparticles of Fe3O4@oleic acid ligands. The ultrasmall-sized Fe3O4 nanoparticles with a good size uniformity enable a high electrochemical activity and a pseudocapacitive-dominated electrochemical behavior. Meanwhile, the efficient ion/electron transportations are facilitated by the structural advantages including covalently interconnected graphitic layers, conformal and seamless graphitic coating with ultrathin thickness, and hierarchical pores. As a result of the synergistic cooperation of these merits, the Fe3O4@OLCs hybrid structure exhibits a high specific capacitance of 686.1 F g−1 at 1 A g−1 and a high rate capability with 71.3% capacitance retention at 10 A g−1, superior to most of the reported Fe3O4-based electrode materials. An asymmetric supercapacitor device assembled based on Fe3O4@ OLCs shows a high energy density of up to 63.1 Wh kg−1, which is still maintained as high as 39.1 Wh kg−1 at a high power density of 1.49 kW kg−1. Moreover, a high cycling stability (more than 80% of initial capacitance remained after 10,000 cycles) is obtained. This study offers a novel strategy for preparing high-performance Fe3O4/carbon hybrid structures for asymmetric supercapacitor applications.

Spinel-structured CuCo2O4 with a mixed 1D/2D morphology for asymmetric supercapacitor and oxygen evolution electrocatalyst applications

Transition metal oxides with multifunctional properties have attracted attention for use in various electro-catalytic applications, but their weak electroactive centers have severely limited their commercialization. In the present study, we describe an efficient bifunctional material whose structural morphology makes it both an effective oxygen evolution reaction (OER) electrocatalyst and a reliable power source for supercapacitor (SC) electrodes. We successfully fabricated spinel-structured CuCo2O4 consisting of a mix of one-dimensional (1D) nanorods and two-dimensional (2D) nanoplates using precipitation followed by hydrothermal treatment and calcination. For comparison purposes, CuO nanoplates and Co3O4 nanorods were synthesized individually, and their multifunctional features were examined. The synthesized mixed-morphology CuCo2O4 delivered an excellent electrochemical performance for SC and OER electrocatalyst applications. The mixed-morphology CuCo2O4 produced a specific capacity of 561 C g−1 (1122 F g−1) at 1 A g−1 and exhibited a superior rate capability and excellent stability, with 92% retention of capacity after 5000 cycles at 30 A g−1 in a three-electrode cell. In addition, a fabricated asymmetric supercapacitor device (CuCo2O4//activated carbon) delivered an energy density of 47.6 W h kg−1 and a power density of 1280 W kg−1, with outstanding long-term cyclic stability. Furthermore, the prepared CuCo2O4 had a low Tafel slope, a high electrochemical surface area, and excellent long-term durability. Therefore, mixed-morphology CuCo2O4 holds significant promise for use in SC and OER catalyst applications. Moreover, this study offers a useful method for preparing multifunctional materials.

In-situ grown of FeCo2O4 @ 2D-Carbyne coated nickel foam - A newer nanohybrid electrode for high performance asymmetric supercapacitors

In this study, we synthesized 2D-carbyne by a simple chemical route coated on nickel foam. To this carbyne coated nickel foam, FeCo2O4 was grown by the solvothermal process to serve as a nanohybrid electrode for asymmetric supercapacitor applications. This nanohybrid electrode has shown high specific capacitance due to the large surface area, high electrical conductivity and improved rate characteristics. The specific capacitance of FeCo2O4 @Carbyne nanohybrid electrode was about 2584.8 Fg−1 at the current density of 3 Ag−1. Furthermore, the asymmetric supercapacitor device assembled using FeCo2O4@Carbyne and activated carbon (FeCo2O4@Carbyne || AC) shows better performance with an energy density of about 93.12 Wh Kg−1 at a high-power density of 2.25 kW kg−1 with a capacitance decay of approximately 26 % even at 5000 cycles. These outcomes provide a new approach for the development of asymmetric supercapacitors with superior characteristics.

Strategies to enhance the electrochemical performance of strontium-based electrode materials for battery-supercapacitor applications

• Sonochemical approach was employed for synthesis of sulfides-based electrode materials. • The optimized electrodes show excellent specific capacity and rate capability. • Hybrid device (SrS//AC) was assembled revealing remarkable energy density (44.39 Whkg -1 ). • Capacitive and diffusive contribution was investigated through Dunn’s model. Asymmetric supercapacitors (SCs) have gained peculiar attention in energy storage domain. However, they still lack to accommodate high specific energy (E s ) and power density (P s ) demands. Therefore, the performance enhancement of supercapacitors by utilizing various electrode materials with superior electrochemical activities is desired. Herein, we have studied various strontium-based materials for asymmetric device applications. Initially, strontium oxide (SrO), phosphide (Sr 3 P 2 ), and sulfides (SrS) were sonochemically synthesized. The structural, morphological, and elemental study were performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). At first, three electrode system was used to execute electrochemical testing, which revealed SrS to hold prime performance compared to SrO and Sr 3 P 2 . The SrS sample obtained high specific capacity (Q s ) of 451.7 C/g (3 mV/s) and 202.5 C/g (0.5 A/g). The electrochemical analysis of the aforementioned SrS electrode was further investigated in two electrode configuration with activated carbon (AC). The device exhibited 44.39 Wh/kg E s and P s of 595 W/kg and attained power of 8400 W/kg while having E s of 12.9 Wh/kg with significant capacity retention of 89.6% over 5000 cycles. Furthermore, a simulation approach was scrutinized to verify the capacitive and diffusive contributions. The results obtained predicts strontium sulfides to be efficient materials for asymmetric supercapacitor applications.

Tuning the crystal structure of NiS/carbon by Mo doping for asymmetric supercapacitor application

A major challenge faced by NiS as positive electrode material for supercapacitors is the capacity attenuation caused by structural changes in the charging and discharging process. In this article, based on theoretical calculations and experimental studies, it is demonstrated that Mo doping can significantly improve the stability and specific capacitance of NiS for supercapacitor application. Experiments show that compared with original NiS/C, the cycle stability of the doped Mo-NiS/C increases by about 30% after 5,000 cycles, and the specific capacitance achieves 1,852 F/g at 1 A/g. Besides, Mo doping can bring better ion contact and increased reaction site to the original lamellar structure of NiS. The calculation results also show that the bond energy of the doped Mo-NiS/C is lower than that of the original NiS/C, which hinders the structural transformation or other side reactions and achieves a better cycle life. This article verifies the effect of Mo doping on the properties of NiS/C and provides a feasible scheme for the study of metal-doped sulfide.

Effect of conducting polymer incorporated heterostructure morphology of MgCo2O4@PPy nanosheets: a novel cathode material for asymmetric supercapacitor applications

Effect of conducting polymer incorporated heterostructure morphology of MgCo2O4@PPy nanosheets: a novel cathode material for asymmetric supercapacitor applications

1T metallic vanadium disulfide hybridized with MXene and functionalized‐MWCNT as a remarkable electrode for high power density asymmetric supercapacitor applications

<scp>1T</scp> metallic vanadium disulfide hybridized with <scp>MXene</scp> and <scp>functionalized‐MWCNT</scp> as a remarkable electrode for high power density asymmetric supercapacitor applications

Construction and application in solid-state asymmetric supercapacitors of gladiolus-like NiSe/CoSe/Ni3Se2 hierarchical nanocomposite with synergistic structural advantages

Gladiolus-like NiSe/CoSe/Ni3Se2 hierarchical nanocomposite supported by nickel foams (NF) was synthesized for the first time by the mixed solvothermal method. Structural characterizations show that the obtained hierarchical nanocomposite forms from the dense growth of NiSe and CoSe nanosheets around Ni3Se2 nanowires. This novel gladiolus-like nanostructure supported by NF possesses the remarkable synergistic structural advantages from 1D/2D nanostructures and porous metallic substrate. It makes the gladiolus-like NiSe/CoSe/Ni3Se2 hierarchical nanocomposite with the excellent electrochemical properties, i.e.: high mass specific capacitance of 1666 F g−1 at 0.5 A g−1, high rate performance of 56.7 % at 2.5 A g−1, and 85.19 % capacitance retention after 5000 cycles. These phenomena are ascribled to the hierarchical nanostructure, heterozygous mettalic atoms, high conductivity, and significant synergistic effect. Subsequently, solid-state asymmetric supercapacitors are built up by using gladiolus-like NiSe/CoSe/Ni3Se2 hierarchical nanocomposite and active carbon as the pair electrodes. This solid-state device has a high areal energy density of 0.33 mWh cm−2 at areal power density of 7 mW cm−2, 80.11 % capacitance retention after 10,000 cycles, and promising commercial value. Thus, the present work not only demonstrates that gladiolus-like NiSe/CoSe/Ni3Se2 hierarchical nanocomposite is the promising electrochemical materials, but also offers a new device for solid-state, small, and smart electronic products. The present groundbreaking work also offers a novel strategy for enhancing the electrochemical capability of supercapacitor electrodes by designing ingenious nanostructures.

3D Prussian blue decorated porous carbon composite electrode for advanced asymmetric supercapacitor applications

Irrational use of fossil fuels led to global warming and pollution. Therefore, the newer technologies should be sustainable and eco-friendly to combat climate change. In this context, supercapacitors (SCs) are demonstrated with carbon materials derived from natural biomaterials. The utilization of biomass-derived materials in energy storage not only converts biowaste material to value-added products but also reduces the production cost. Although SCs exhibit high power density, they are not considered a primary energy source due to their poor energy density. By taking advantage of the present work's asymmetric configuration, the operating voltage window and energy density of aqueous SCs are significantly enhanced. An asymmetric SC is developed by combining a porous 3D cubical-shaped Prussian blue (PB) decorated carbon derived from tamarind seeds (ACTS-800) (PB/ACTS-800) positive electrode with ACTS-800 negative electrode and aqueous 3 M KNO3 electrolyte. The resulting ACTS-800//PB/ACTS-800 (1:2) asymmetric SC demonstrated a broad electrochemical stable voltage window of 2.2 V in the aqueous medium. Impressively, a high energy density of 60 Wh/kg @ 551 W/kg realized is much superior to most of the carbon/carbon SCs operated in an aqueous medium.

Defect rich Se–CoWS2 as anode and banana flower skin-derived activated carbon channels with interconnected porous structure as cathode materials for asymmetric supercapacitor application

We propose the Se heteroatoms incorporated CoWS2 (Se–CoWS2) as anode and banana flower skin-derived activated carbon (BFS-AC) as cathode for energy storage application. Herein, the Se–CoWS2 was prepared by using hydrothermal and selenization methods, while the BFS-AC was prepared by following the carbonization method. The formation of anode and cathode active materials were confirmed by using various analytical techniques. In electrochemical studies, the Se–CoWS2 modified nickel foam (NF) exhibits the lower charge transfer resistance (Rct) and higher specific capacity (452 C/g at current density of 0.5 A/g) and long term stability (96.15% retention after 2,000th cycles). Fortunately, the fabricated asymmetric device (Se–CoWS2//BFS-AC) has delivered a satisfactory energy density of 107.87 W h kg−1 at a power density of 1600 W kg−1. And also, the device retains its 95.33% of Coulombic efficiency up to 3000 continuous charge/discharge cycles. In light emitting diode (LED) tests, the device lights up the LED around 30 min, which indicates the practicability of proposed asymmetric device. Finally, this study addresses that the heteroatom incorporation with metal chalcogenides can be one of the suitable methods to prepare the electrode materials with necessary electrochemical properties. In addition, the biomass-derived carbon can facilitate better charge balance in asymmetric configuration.

Binder‐Free Synthesis of Mesoporous Nickel Tungstate for Aqueous Asymmetric Supercapacitor Applications: Effect of Film Thickness

Nickel tungstate thin films of different thicknesses are synthesized using the binder‐free successive ionic layer adsorption and reaction (SILAR) method at ambient temperature and subsequent calcination at a temperature of 727 K. The physicochemical characterizations of NiWO4 thin films are carried out using different techniques. The electrochemical performances of NiWO4 films are evaluated in 2 m KOH electrolyte using a standard three electrode system. The specific capacitance of 1536 F g−1 at the current density of 2 A g−1 is obtained for the NiWO4 film. The film exhibits excellent electrochemical stability of 87% after 5000 galvanostatic charge–discharge (GCD) cycles at the current density of 3 A g−1. This study highlights use of SILAR‐deposited NiWO4 thin films as a cathode in aqueous asymmetric supercapacitors (ASCs). The ASC device NiWO4/KOH/Fe2O3 exhibits a specific capacitance of 115 F g−1 at 2 A g−1 and specific energy of 23Wh kg−1 at specific power of 1.2 kW kg−1. The device shows remarkable electrochemical cycling stability (78% capacitance retention after 5000 GCD cycles). The SILAR‐deposited NiWO4 thin films are expected to emerge as a potential candidate for supercapacitors.

Synergistic effect of La2o3 -Nio nanocomposite based electrode for electrochemical high-performance asymmetric supercapacitor applications

Global economic growth and rapid industrial development have resulted in a severe energy problem. Renewable energy sources have been replaced by alternative and sustainable energy sources. Super capacitors are one of the most important types of energy storage devices. The development of supercapacitor electrodes with maximum performance is currently the most important research topic in this area. Here we present the results of hydrothermal research on rare earth-based nanocomposites of Lanthanum-Nickel La2O3 -NiO-based electrodes for electrochemical super capacitor applications. XRD, FTIR, TG/DTA, SEM, TEM and EDAX techniques are used to examine the physico-chemical characteristics such as crystallographic structure, vibrational characteristics, thermal stability morphology, chemical composition, and its features respectively. According to the cyclic voltammetry (CV) investigation, the prepared nanocomposite materials have a Specific capacitance of 704 F/g at scan rate of 5 mV/s. EIS analysis demonstrates the RsValues ofLa2O3 (0.11549 Ω) NiO(0.1937 Ω) La2O3 -NiO(0.641 Ω) increased conductivity of nanocomposite material. According to galvanostatic charge–discharge (GCD) tests, the La2O3 -NiO electrode has a maximum specific capacitance of 564 F/g at 1 A/g current density in 1 M KOH electrolyte. This result proved that the prepared (La2O3 -NiO Nanocomposite), electrode material used for practical application, which shows good capacitive retention of 93.4%even after 2000 cycles. More ever asymmetric device constructed superior cyclic stability of 77.2%of capacitive retention even after 2000 charge discharge cycle.