Electrode For Asymmetric Supercapacitors Research Articles

Copper Phosphosulfide Nanosheets on Cu-Coated Graphene Fibers as Asymmetric Supercapacitor Electrodes

Copper Phosphosulfide Nanosheets on Cu-Coated Graphene Fibers as Asymmetric Supercapacitor Electrodes

Chemical vapor deposition-grown single-layer graphene-supported nanostructured Co3O4 composite as binder-free electrode for asymmetric supercapacitor and electrochemical detection of caffeic acid

In this study, we developed a monolayer graphene/nanostructured cobalt oxide (MLG/Co3O4) composite for asymmetric supercapacitor and electrochemical sensor applications. The MLG was grown by chemical vapor deposition process and the Co3O4 nanostructures were electrodeposited on the MLG surface. Scanning electron microscopy proved that there were flower-like nanostructured Co3O4 densely electrodeposited on the MLG surface. At a current density of 3 mA cm−2, the MLG/Co3O4 composite produced an areal capacitance of 3.73 F cm−2. After 10,000 cycles, the composite electrode still had 93.6 % of its initial capacitance at 5 mA cm−2. The asymmetric system displayed an areal capacitance of 929 mF cm−2 at 4 mA cm−2 with good cycle stability. The asymmetric electrode produced a specific energy of 51 μWh cm−2 and a specific power of 11.1 mW cm−2. Cyclic voltammetric measurements demonstrated that the composite showed redox peaks at 0.48 eV and 0.09 eV toward the determination of CA. With a sensitivity of 0.13 µA/µM/cm2 and a limit of detection of 0.009 µM, the composite showed CA concentrations, ranging from 0.5 to 480 M. The composite displayed excellent selectivity and the current produced for the interfering compounds was exceedingly low. Using the composite electrode, the spiked CA in red wine and green tea samples recovered remarkably effectively.

Influence of Deposition Potential on Electrodeposited Bismuth–Copper Oxide Electrodes for Asymmetric Supercapacitor

AbstractThe modern research reported the simplest low–cost synthesis of Bismuth–Copper oxide (Bi2CuO4) with spruce–leaf–like morphology and its applications in supercapacitor devices. Bi (NO3)3 . 5H2O was used as a precursor during an electrodeposition (ED) method to create the spruce–leaf–like Bi2CuO4 electrode. XRD, XPS, FE−SEM, EDX, and TEM were used to characterize the structures and morphologies of the synthesized materials, while CV, CP, and EIS were used to determine their electrochemical characteristics. The Bi2CuO4 phase was confirmed by XRD patterns, and electrochemical testing demonstrated that the material had better rate capability and an SC of 431.2 F/g at a scan rate of 2 mV/s. After 5,000 cycles, it retained 81.4 % of its energy. Additionally, the maximum SC that was attained by the created asymmetric solid–state device ASSD (Bi0.6 Vǀǀ1 M PVA−KOHǀǀAC) was 73.7 F/g. The energy density was 55.3 Wh/Kg at a power density of 4570 W/Kg. The exceptional electrochemical performance of Bi2CuO4 thin film electrodes recommends it has a promising material.

Hierarchical flower bud-like P, W co-doped NiCo2S4@MoS2 composites as high-performance electrodes for asymmetric supercapacitor

Engineering binary transitional metal sulfides (BTMSs)-based electrode materials with a rationally designed constituent architecture is a viable strategy for improving their rate capability and electrochemical durability, which provides a possibility for their application in supercapacitors (SCs). Herein, a novel three-dimensional (3D) flower bud-like phosphorus and tungsten co-doped NiCo2S4 and MoS2 composites (P, W-NCS@MS) is prepared on conductive carbon cloth using the hydrothermal method. The effects of P, W-doping, or MoS2-combination on the morphology, structure and electrochemical properties of NiCo2S4-based electrode materials are systematically studied. The designed P, W-NCS@MS achieves a high specific capacity of 1250C g−1 at 1 A g−1 and a satisfactory capacity retention of 80 % after 10,000 cycles. In addition, the asymmetric supercapacitor (ASC) constructed through P, W-NCS@MS and activated carbon electrodes delivers a high energy density of 65.0 Wh kg−1 at the power density of 400 W kg−1 and shows satisfactory cycling stability of 85 % capacitance retention after 20,000 cycles. Notably, the assembled ASC device successfully powered electronic devices in a serial circuit, highlighting its prospective applications in energy storage. This work offers a viable design approach for heteroatom doping and hierarchical interface structures in composite electrode materials toward high-performance SCs.

V2O5-assembled NiAl-layered double hydroxide as high-performance electrode for asymmetric supercapacitor

V2O5-assembled NiAl-layered double hydroxide as high-performance electrode for asymmetric supercapacitor

Heterostructured SnSe-MnSe@rGO as a composite electrode for Li-ion batteries and high energy density asymmetric supercapacitors

Systematically fabricated hybrid nanomaterials have good outer walls and inherent features, which can significantly improve energy storage capabilities. Herein, we demonstrated the successful preparation of heterostructure SnSe-MnSe nanomaterials anchored reduced Graphene oxide using the hydrothermal method. The SnSe-MnSe@rGO is used as the composite electrode for lithium-ion battery and supercapacitor applications. The SnSe, MnSe, and SnSe-MnSe materials were also prepared and compared their performances with the SnSe-MnSe@rGO material. The first cycle charge/discharge capacity of SnSe-MnSe@rGO was 484.6/641.9 mAhg−1 at 0.1Ag−1 with coulombic efficiency of 75.49 %. After 1000 cycles at 1Ag−1, the SnSe-MnSe@rGO delivered the discharge capacity of 175.7 mAhg−1 at 1Ag−1 with 72.75 % retention of capacity. For supercapacitor application, the SnSe-MnSe@rGO exhibits the battery-type energy storage mechanism and provides a specific capacity of 210. 8 mAhg−1 at 1 Ag−1 with superior rate capability and it withstands 94 % of initial capacity after 5000 GCD cycles at 20 Ag−1 in three-electrode electrochemical cells. The asymmetric type such as activated carbon//SnSe-MnSe@rGO device delivers the capacity of 105.8 mAhg−1 and shows a high energy density of 84.7 Whkg−1 with the power density of 810.5 Wkg−1 at 1 Ag−1. The device holds 89 % of its initial capacity retention after 10,000 continuous GCD cycles at 10 Ag−1. This study emphasizes a comprehensive and fundamental understanding of the reaction mechanisms at the heterostructures, as well as the strategic design of composite materials for constructing advanced electrodes in the realm of sustainable energy storage applications.

PPy-PdO modified MXene for flexible binder-free electrodes for asymmetric supercapacitors: Insights from experimental and DFT investigations

Binder-free, flexible electrodes of V2C MXene, V2C-PPy, and V2C-PPy-PdO (a ternary composite of vanadium carbide, polypyrrole, and palladium oxide) were fabricated using a simplified, one-step electrodeposition method. A comprehensive assessment has subsequently been conducted on the microstructural and electrochemical attributes of these electrode materials when utilized in supercapacitors with a 1 M H2SO4 electrolyte. Notably, an impressive specific capacitance of 487F g−1 is achieved for V2C-PPy-PdO ternary composite at 1 A/g. This exceptional performance is due to the considerable active surface area and inherent structural stability of the host material. These factors significantly enhanced the electrochemical reaction kinetics and cyclic reversibility. Furthermore, the V2C-PPy-PdO composite demonstrated a notable specific capacitance of 250F g−1 when integrated into an asymmetric coin cell configuration alongside activated porous carbon under a current density of 1 A/g. Remarkably, it maintained an outstanding capacitance retention of 92 % across 10,000 charge–discharge cycles. Our experimental discoveries were additionally substantiated through the Density Functional Theory calculations, which unveiled that the inclusion of PdO within the V2C-PPy-PdO composite led to an augmentation of electronic states near the Fermi level. This increase in electronic states ultimately improved the quantum capacitance, rendering the V2C-PPy-PdO composite a highly promising candidate for supercapacitor applications.

Preparation of Sea Urchin‐Like Co/Ni Alloy Compounds for Pseudocapacitive Supercapacitor

Energy density and power density are the two most crucial metrics in advanced electrochemical energy storage (EES) devices. The design of pseudocapacitor materials with good structure and reasonable composition can ensure that the power density can be greatly increased under the condition of little or no reduction in energy density. However, how to reasonably design excellent pseudocapacitor materials is still a huge challenge. Herein, layered double hydroxides containing Ni and Co elements on carbon materials derived from distillers’ grains by hydrothermal synthesis (NiCo‐LDH/JKPC‐2) are grown. The fabricated NiCo‐LDH/JKPC‐2 has exhibited a sea urchin‐like nanostructure that primarily consists of mesoporous and possesses a high specific surface area (303 m2 g−1), which facilitates the formation of larger active sites, thereby increasing the rate of charge transport. The specific capacitance of the NiCo‐LDH/JKPC‐2 reaches a maximum value of 1454 F g−1 at 1 A g−1. When it combines with carbon materials originating from distillers’ grains, the assembled asymmetric supercapacitor electrode exhibits a remarkable energy density (40.86 Wh kg−1 at 775 W kg−1) and superior power density (7750.8 W kg−1 at 21.53 Wh kg−1). Thus, the NiCo‐LDH/JKPC‐2 asymmetric supercapacitor electrode can be considered as a potential candidate in advanced energy storage device systems.

Facile synthesis of NiMoO4@MnO2 nanoflower and waste biomass-derived N, P, and S self-doped carbon for advanced asymmetric supercapacitor electrode materials

Green energy storage technologies have been demonstrated by the use of sustainable biomass-derived carbon as an electrode. Herein, for a high performance all-solid-state asymmetric supercapacitor, we used biowaste material to derive multi-heteroatom doped carbon as a non-faradaic electrode along with NiMoO4@MnO2 Nano-flower-like hybrid structure on nickel foam as a Faradaic electrode. Due to the combined effect of the large specific surface area, hierarchical porous structure of biomass-derived activated carbon (FDAC3) and the highly specific capacitance of the NiMoO4@MnO2 hybrid, designed all-solid-state asymmetric supercapacitor achieved a remarkable specific capacitance of 109.1 F g−1 at 1.4 A g−1 and maximum specific energy of 54.7 Wh/kg within a voltage window of 1.8 V. Moreover, for the practical application of designed cell devices, two different devices were connected in a series to light up different colors light emitting diodes (LEDs). These findings provide new insights to realize the full utilization of biomass waste and a novel low-cost pathway for producing high-performance materials for energy storage applications.

Rational design and synthesis of a 3D hierarchical NiCo-LDH/C/GF composite foam as advanced electrodes for asymmetric supercapacitors

Rational design and synthesis of a 3D hierarchical NiCo-LDH/C/GF composite foam as advanced electrodes for asymmetric supercapacitors

Co3O4 nanowire modified with carbon nanotubes to be used as improved asymmetric supercapacitor electrode

Co3O4 itself suffers from drawbacks such as poor conductivity and a low active site density, significantly limiting its application in capacitors. To address this issue, this study employs a one-step hydrothermal method to incorporate carbon nanotubes (CNTs) into Co3O4, resulting in the fabrication of Co3O4/CNTs composite nanomaterials. In comparison to the pristine Co3O4 material, this composite exhibits a 69.7 % improvement in specific capacitance. When Co3O4/CNTs and activated carbon (AC) are assembled into asymmetric capacitors, an impressive energy density of 58.46 Wh Kg−1 (461.52 W Kg−1) is achievable at room temperature, with a capacitance retention rate of 83.2 % observed after 65,000 charge-discharge cycles. The addition of CNTs made the Co3O4 nanowire clusters and their binding with nickel foam more tightly, increasing the conductivity of the material and exposing more active sites while improving stability. This study offers valuable insights for further advancements and practical applications of electrode materials in supercapacitors.

ZIF-67 derived high stability CoNi2S4/carbon/MXene composites as an enhanced electrode for asymmetric supercapacitor

Supercapacitors have received widespread attention from scientific researchers due to the advantages of high power density, fast charging/discharging rate and long cycle life. Among them, the development of high performance and high safety electrode materials are important research topics in the field of supercapacitors. Herein, zeolitic imidazolate framework (ZIF) derivatives is a good candidate material for supercapacitors electrode because of its controllable pore rate, constant cavity and larger specific area. However, the reunion phenomenon and the damaged structure during the reaction seriously affected its electrochemical properties, especially its stability. To solve this problem, the few-layer MXene was added into ZIF-67 to inhibit the reunion of single materials and the carbonization process was operated to improve its conductivity and structure stability. In addition, the CoNi2S4/carbon/MXene (CNS/C/MXene) obtained by the solvent thermal method successfully inherited the hollow cages structure and rough surface from the precursor, expressing a better electrochemical performance. In three-electrode system, the CNS/C/MXene electrode can exhibit the specific capacitance of 1221.6 F g−1 (169.7 mAh g−1) at 1 A g−1 and still maintain a high capacitance of 966.4 F g−1 (134.2 mAh g−1) at 20 A g−1 (79.1 % of the former). After assembling it with activated carbon into asymmetric supercapacitor, the device can provide a high energy density of 19.82 Wh kg−1 at a power density of 469.31 W kg−1 and maintain about 71.17 % of the initial capacitance after 30,000 cycles under a current density of 20 A g−1, representing excellent cycle stability and rate capability.

Vertically aligned graphene-MXene nanosheets based electrodes for high electrochemical performance asymmetric supercapacitor

Vertically aligned porous morphologies have attracted much attention due to their long-range ordered channel structures. Here, a novel 3D vertically aligned graphene-MXene nanosheets based electrochemical supercapacitor is designed. Graphene oxide and Ti3C2TX MXene are used to prepare a vertically aligned porous bridge substrate (the pore size of 7 μm) by an ice template directional solidification method. Polyaniline nanowire arrays (PANI NWAs) are in-situ grown on the substrate by a polymerization process (positive electrode) and the substrate with more MXene is used as the negative electrode. After assembling into an asymmetric supercapacitor (ASC), the vertically aligned porous morphology is conducive to accelerating the directional transport of ions, which obviously improves the electrochemical properties of the ASC. The calculated specific capacitance of the ASC is 108F/g (at 1 A/g). The energy density of the ASC can reach 38 Wh/kg (at the power density of 810 W/kg) and the cycle stability is 82 % after 10, 000 cycles at 10 A/g.

Construction of MOFs derived porous carbon based core–shell hetero-structure electrode for superior asymmetric supercapacitor

The design of electrode materials with high performance is very important to improve the energy density of supercapacitors (SCs). The combination of electrical double layer capacitor and pseudo-capacitive materials can significantly improve the electrochemical performance of material, but reasonable structural design can inhibit the slow Faraday dynamic mismatch caused by different storage mechanisms. In this study, NiCoB nanosheets were grown on the surface of cobalt metal-organic frameworks (Co-MOF) derived porous carbon (Co-C) by chemical precipitation method to form a core–shell hetero-structure Co-C@NiCoB electrode. The Co-C@NiCoB electrode has the specific capacitance of 2990 F g−1 at 1 A g−1, which is significantly higher than that of Co-C (416 F g−1) and NiCoB (1052 F g−1). In order to further increase the energy density of the device, the carbon nano-sheets with cactus shape as cathode were obtained by calcination of Co-MOF (CNS). The asymmetric SCs with CNS as cathode and Co-C@NiCoB as anode have a high energy density of 66.03 Wh kg−1 at the power density of 763.35 W kg−1 and exceptional cycling life with capacitance retention of 92.1 % over 10,000 cycles.

Synergistic CuCoS-PANI materials for binder-free electrodes in asymmetric supercapacitors and oxygen evolution.

In advanced electronics, supercapacitors (SCs) have received a lot of attention. Nevertheless, it has been shown that different electrode designs that are based on metal sulfides are prone to oxidation, instability, and poor conductance, which severely limits their practical application. We present a very stable, free-standing copper-cobalt sulfide doped with polyaniline as an electrode coated on nickel foam (CuCoS/PANI). The lightweight nickel foam encourages current collection as well as serving as a flexible support. The CuCoS-PANI electrode had a substantially greater 1659 C g-1 capacity at 1.0 A g-1. The asymmetric supercapacitor (ASC) can provide an impressive 54 W h kg-1 energy density while maintaining 1150 W kg-1 power. Additionally, when employed as an electrocatalyst in the oxygen evolution reaction, CuCoS/PANI exhibited a 200 mV overpotential and 55 mV dec-1 Tafel slope, demonstrating its effectiveness in facilitating the reaction.

Valence state regulation of iron oxide composited with graphene towards negative electrodes in asymmetric supercapacitors

A strategy based on a laser-induced method for the in situ synthesis of LIG/Fe3O4 composites was developed. The Fe3+/Fe2+ ratio was modulated to exhibit optimal electrochemical performance.

Ni0.5Co0.5S nano-chains: a high-performing intercalating pseudocapacitive electrode in asymmetric supercapacitor (ASC) mode for the development of large-scale energy storage devices.

Grid-scale energy storage solutions are necessary for using renewable energy sources efficiently. A supercapattery (supercapacitor + battery) has recently been introduced as a new variety of hybrid devices that engage both capacitive and faradaic charge storage processes. Nano-chain architectures of Ni0.5Co0.5S electrode materials consisting of interconnected nano-spheres are rationally constructed by tailoring the surface structure. Nano-chains of the bimetallic sulfide Ni0.5Co0.5S are presented to have a superior charge storage capacity. The Ni0.5Co0.5S nano-chain electrode presents a capacitance of 2001.6 F g-1 at 1 mV s-1, with a specific capacity of 267 mA h g-1 (1920 F g-1) at 1 A g-1 in 4 M KOH aqueous electrolyte through the galvanostatic charge-discharge (GCD) method. The reason behind the high charge storage capacity of the materials is the predominant redox-mediated diffusion-controlled pseudocapacitive mechanism coupled with surface capacitance (electrosorption), as the surface (outer) and intercalative (inner) charges stored by the Ni0.5Co0.5S electrodes are close to 46.0% and 54.0%, respectively. Additionally, a Ni0.5Co0.5S//AC two electrode full cell operating in asymmetric supercapacitor cell (ASCs) mode in 4 M KOH electrolyte exhibits an impressive energy density equivalent to 257 W h kg-1 and a power density of 0.73 kW kg-1 at a current rate of 1 A g-1.

A 3D hydrangea-like NiMoO4/rGO/PANI hybrid composite for high performance asymmetric supercapacitor

Development of electrode materials exhibiting exceptional stability and possessing a high specific capacitance is the important task within the realm of supercapacitor research. In this study, a novel micro-architecture of NiMoO4 (NMO) resembling a hydrangea in three dimensions (3D) has been developed. The surface of NMO was modified by anchoring PANI nanoparticles and reduced graphene oxide (rGO) resulting in the formation of a composite material designated as NiMoO4/rGO/PANI (NMORP). The NMORP composite demonstrates a notable increase in specific-capacity, reaching 1150 C g−1 when tested at 1 A g−1. The observed capacity retention percentage of 97.5 % after undergoing 5000 cycles on a notable current density (10 A g−1) provides substantial proof of exceptional cycling performance within the cycling domain. The remarkable outcomes observed can be attributed to the synergistic impact of the structural and componential characteristics of the NMORP composite. The higher cycling stability of the NMORP composite electrode may be ascribed to the 2D–2D coupling phenomenon occurring at the interface of reduced graphene oxide (rGO) and NMO nanosheets, together with the stable 3-D design reminiscent of hydrangea flowers. Furthermore, the NMORP composite, characterized by a pore structure ranging from 10 to 20 nm and higher conductivity, demonstrates enhanced capabilities regarding the transfer of charge and diffusion of ions. In addition, the NMORP//AC supercapacitor shows a remarkable energy density of 82.43 Wh kg−1 at 850 W kg−1 power density. Furthermore, it shows exceptional cycling performance, retaining 94.5 % of its capacity with 10 A g−1 current density upon the completion of 10,000 cycles. The fabrication of a composite material, referred to as NMORP, presents a viable approach to address the challenges associated with the inadequate electrochemical durability and sluggish electron/ion transfer exhibited by NMO composite when utilized as an electrode in asymmetric supercapacitors (device).

A new binder-free ZnS-CuO microsphere: A battery-type electrode material for asymmetric supercapacitor

The supercapacitor has emerged as a viable solution to address the energy demands of industries and mitigate the environmental concerns associated with fossil fuel utilization. Hence, in this study, binder-free ZnS-CuO microspheres are reported for the first time and directly utilized as a battery-type electrode for asymmetric supercapacitor (ASC) applications. The current study demonstrates an exceptional electrochemical performance by optimizing the composition, structure, and morphology. The increased surface area and abundance of active sites contribute to the enhanced ion transfer efficiency between the electrolyte and the electrode, promoting rapid ion exchange. The electrochemical properties reveal a maximum capacitance of 561 F/g with excellent charge storage capacity, and good rate capability. The CuO-ZnS||AC ASC was built that operates in a broad voltage window of 1.6 V, and a capacitance of 175 F/g in an aqueous solution. It delivers the highest specific energy of 62 Wh/kg with an excellent power delivery of 8640 W/kg and remarkable stability of 93.2 % after 5000 cycles. Nevertheless, there is a prevailing optimism regarding the potential for optimizing synthesis procedures, which may ultimately result in the practical implementation of these innovative materials for efficient energy storage in the near future.

Facile synthesis of layered reduced graphene oxide/polyaniline (rGO/PANI) composite electrode for flexible asymmetric solid-state supercapacitor

For supercapacitors, composite electrodes with a combination of reduced graphene oxide and polyaniline (rGO/PANI) have gained a lot of attention due to their synergistic effects. In this study, rGO-PANI composite thin films were deposited on a stainless steel substrate with various mass loadings by successive ionic layer adsorption and reaction (SILAR) method. The specific surface area rises from 13 m2 g−1 to 30 m2 g−1 with the introduction of rGO. Due to the composition modification and specific surface area enhancement, the specific capacitance (capacity) of 1348 F g−1 (1255C g−1) was obtained at 0.89 mg cm−2 mass deposition. Additionally, rGO/PANI/PVA-H2SO4/AC flexible asymmetric solid-state supercapacitor (ASSS) showed specific energy of 20 Wh kg−1 at specific power of 1198 W kg−1. The device maintained almost 96 % of Cs at bending angle of 160° and 75 % over 5000 cycles. This work illustrates a simple way to improve the capacity and stability of PANI via rGO composition for supercapacitor applications.