High-performance Asymmetric Supercapacitors Research Articles

Photo-assisted charging of heterostructured NiCo2S4@NiCo-LDH composite electrode with remarkable photoelectronic memory effect for high-performance asymmetric supercapacitor

Rational establishment of photo-assisted supercapacitor represents a viable strategy for achieving solar energy conversion and storage. In this study, NiCo2S4@NiCo-LDH (NCS@NC-LDH) composite electrode was effectively synthesized for a highly efficient asymmetric supercapacitor (ASC). Specific capacitance of NCS@NC-LDH under light condition (3286.25 F g−1 at 1 A g−1) demonstrated notable improvement in contrast to that under dark condition (2171.5 F g−1 at 1 A g−1). Meanwhile, NCS@NC-LDH displayed strong photoelectronic memory, as a merely 3 % specific capacitance decreased when discharged under dark compared to that of continuous illumination. Additionally, the assembled aqueous ASC (NCS@NC-LDH//AC) exhibited substantial energy density (83.2 Wh kg−1 at 800 W kg−1) under light condition. Density functional theory (DFT) calculation further demonstrated that the formed matched band facilitated efficient generation-transfer of photoinduced electrons/holes and thus improved the energy storage behavior. We anticipated that this work may offer new perspectives on developing multi-component composite electrodes tailored for high-performance solar-driven electrochemical energy storage.

Enhancing heterojunction interface charge transport efficiency in NiCo-LDHs@Co/CoO-CNFs for high-performance asymmetric and zinc-ion hybrid supercapacitors

Enhancing heterojunction interface charge transport efficiency in NiCo-LDHs@Co/CoO-CNFs for high-performance asymmetric and zinc-ion hybrid supercapacitors

High-performance asymmetric supercapacitor based on hierarchical hydrothermally grown CuS nanostructures

In this work, various hierarchical CuS were fabricated via an efficient one-step hydrothermal process with different surfactants (polyvinyl pyrrolidine (CS-P), Citric acid (CS-C), Oleic acid (CS-O)) and examined as electrode materials for supercapacitors. XRD, FESEM, HRTEM and BET analysis reveal the fabrication of a hexagonal crystal structure with porous microspheres of CuS-PVP having a BJH pore diameter of 16.241 nm. Among these, the CS-P electrode exhibits a superior specific capacitance of 414.28F/g at 1 A/g of current density in the KOH electrolyte. Additionally, an asymmetric supercapacitor built with CS-P as positive and Activated carbon as negative electrodes exhibited a specific energy of 27.95 Wh/kg at 624.96 W/kg of specific power at 2 A/g and demonstrated outstanding cycling stability with 80.6 % persistence of capacitance for 2500 GCD cycles at 10 A/g. Additionally, an ASC device created for use in real life and tested by charging it for 30 s managed to reach a 3-minute 50-second self-discharging duration. Hence, these favourable electrochemical findings indicate that the hydrothermally grown hierarchical CuS-PVP electrode is a bright potential material in energy storage applications.

High-performance pristine ZIF-67 asymmetric supercapacitor device with excellent energy and power density for energy storage application

The current work describes a simple and safe method for creating ZIF-67 (zeolitic imidazolate framework-67) nanostructures. X-ray diffraction (XRD) patterns reveal that the material exhibits a cubic phase free from contaminating impact. The synthesized material has a notable porosity, a high specific surface area (SSA) of ∼ 1071 m2 g−1, and a clearly defined hexagonal shape with high-resolution transmission electron microscope (HRTEM) analysis. Moreover, the electrochemical analysis in the three-electrode setup shows an extraordinary specific capacitance (CS) of 472 F g−1 and exceptional cyclic performance of 91.6 % retention in a 6 M NaOH aqueous electrolyte. Furthermore, activated carbon (AC) is being used as the negative electrode and ZIF-67 as the positive electrode to design a device with a wide potential window (1.50 V). The outstanding performance of the Asymmetric supercapacitor (ASC) device is evident in its exceptional CS (358 F g−1). This, coupled with its remarkable energy (22 Wh kg−1) and power density (4164 W kg−1), highlights its suitability for demanding energy storage applications. Notably, the device demonstrates extraordinary cyclic stability, retaining over 132 % of its initial capacitance after 5000 charge-discharge cycles, solidifying its long-term reliability. Finally, LEDs (Light Emitting Diodes) of various colors are being illuminated using three series-connected devices. Hence, the recent work is illustrating the possible practical benefit of the ongoing development of supercapacitive energy storage systems.

Stepwise Construction of MoS2@CoAl-LDH/NF 3D Core-Shell Nanoarrays with High Hole Mobility for High-Performance Asymmetric Supercapacitors.

Supercapacitors (SCs) have received widespread attention as excellent energy storage devices, and the design of multicomponent electrode materials and the construction of ingenious structures are the keys to enhancing the performance of SCs. In this paper, MoS2 nanorods were used as the carrier structure to induce the anchoring of CoAl-LDH nanosheets and grow on the surface of nickel foam (NF) in situ, thus obtaining a uniformly distributed MoS2 nanorod@CoAl-LDH nanosheet core-shell nanoarray material (MoS2@CoAl-LDH/NF). On the one hand, the nanorod-structured MoS2 as the core provides high conductivity and support, accelerates electron transfer, and avoids agglomeration of CoAl-LDH nanosheets. On the other hand, CoAl-LDH nanosheet arrays have abundant interfacially active sites, which accelerate the electrolyte penetration and enhance the electrochemical activity. The synergistic effect of the two components and the unique core-shell nanostructure give MoS2@CoAl-LDH/NF a high capacity (14,888.8 mF cm-2 at 2 mA cm-2) and long-term cycling performance (104.4% retention after 5000 charge/discharge cycles). The integrated MoS2@CoAl-LDH/NF//AC device boasts a voltage range spanning from 0 to 1.5 V, achieving a peak energy density of 0.19 mW h cm-2 at 1.5 mW cm-2. Impressively, it maintains a capacitance retention rate of 84.6% after enduring 10,000 cycles, demonstrating exceptional durability and stability.

Facile Synthesis of 3D Cu(OH)2@NiCo-Binary Hydroxide Core–Shell Nanotube Arrays with High Mass Loading for High-Performance Asymmetric Supercapacitors

Facile Synthesis of 3D Cu(OH)₂@NiCo-Binary Hydroxide Core–Shell Nanotube Arrays with High Mass Loading for High-Performance Asymmetric Supercapacitors

Rational design of the binder-free polythiophene nanofibers deposited nickel foam for the high-performance aqueous asymmetric supercapacitor

Development of the binder-free electrode materials and employing in the supercapacitor is the essential footstep for high energy storage. The present study highlights the cost-effective synthesis strategy for the binder-free growth of the amorphous polythiophene nanofibers over the nickel foam substrate. The presence of functional bonds like CC, C-H, and C-S has confirmed the deposition of the polythiophene nanofibers on the nickel foam, while elemental mapping analysis detected the uniform distribution of Carbon and Sulfur elements over nanofibers. The surface structure of the polythiophene is transformed from nanofibers to a wire-like structure as the result of the monomer concentration variation. The optimized polythiophene film exhibited the highest areal capacitance of 1263.2 mF/cm2 at 2 mA/cm2 with 90.03% capacitance retention after 5000 cycles. Moreover, the aqueous asymmetric device (PTh//AC) is fabricated which delivered 31.5 F/g at 10 mA/cm2. The highest specific energy of PTh//AC device was 6.3 Wh/kg. Also, it showed good retention capability with 82.3% retention. Based on these results, the present investigation provides the performance metrics of the polythiophene nanofibers and highlights the potential utilization of the polythiophene-based supercapacitor in practical energy storage systems.

Microcubes of ZnSe–SnSe2 Encapsulated within Graphene for High-Performance Asymmetric Supercapacitors

Microcubes of ZnSe–SnSe₂ Encapsulated within Graphene for High-Performance Asymmetric Supercapacitors

Nickel-molybdenum bimetallic sulfide decorated biomass derived carbon support for high performance asymmetric supercapacitor application

Biomass - derived carbon electrode material with a porous structure is widely used in supercapacitor applications, which can improve electron transfer and shorter ion diffusion pathways. In this work, the garlic peel biomass carbon (GPBC), NiMo3S4(NMS) and garlic peel biomass carbon decorated with NiMo3S4 (GPBC/NMS) composite were prepared through a in situ two-step hydrothermal method. The synthesized materials were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM), energy dispersive x-ray spectroscopy (EDS), Transmission electron microscopy techniques (TEM), Raman spectroscopy and Brunauer-Emmett-Teller (BET) techniques were used to analyze the structure, morphology and specific surface areas and X-ray photoelectron spectroscopy (XPS). The prepared bimetallic metal sulfide on a biomass - derived carbon namely the GPBC/NMS composite is used in supercapacitor application. The GPBC/NMS composite electrode exhibits good cycle performance with high specific capacity of 304C/g at current density of 1 A/g in a 3 M KOH electrolyte solution. The electrochemical performance of the GPBC/NMS//GPBC asymmetric supercapacitor device produces an excellent energy density 45.5 Wh kg−1 at a power density of 1125 W kg−1 in the 1.6 V operating potential window. The GPBC/NMS//GPBC also exhibits 93 % retention of its initial capacitance after the 10,000 GCD cycle performance. The above results demonstrate a new way of developing high performance electrode materials for energy storage applications.

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.

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

3D Architecting triple gradient graphene-based fiber electrode for high-performance asymmetric supercapacitors

High-performance fibrous architectures and controllable fabrication methods for active nanomaterials are fundamental in the development of fiber-based supercapacitors (FSCs). Herein, we rationally designed a triple gradient structured fibrous electrode based on three-dimensional (3D) architectural approach with Ni3S2 nanoflakes (Ni3S2 NFs) in situ growth on Ni-coated graphene fiber (Ni3S2-NiGFs) for highly energy-dense asymmetric supercapacitors. Remarkably, the Ni-metal coating imparted the Ni3S2-NiGFs exceptional electrical conductivity (619.8 S cm−1), mechanical strength (335.0 MPa), and flexibility without significantly compromising its density. Moreover, the unique 3D interconnected ultrathin Ni3S2 NFs significantly increase the contact area between the electrode and the electrolyte solution, providing abundant redox activity to facilitate ion transport and accumulation. Therefore, the fibrous electrode showcased a remarkable areal specific capacitance of 1387.6 mF cm−2 at 3 mA cm−2 in 3 M KOHaq electrolyte, while its asymmetric FSCs delivered an impressive areal energy density of 15.6 μW h cm−2 at power density of 1.0 mW cm−2 along with durable cycle life (86.7 % of the initial specific capacitance retention over 10,000 cycles). In summary, the featured work provides a facile but robust electrode design to realize highly energy-dense flexible energy storage devices for next-generation wearable industries.

Fabrication of NiCo2O4@NiCo2S4 Core@Shell nanostructured arrays decorated over the rGO sheets for High-Performance asymmetric supercapacitor

Reliable and cost-effective energy storage systems can only be designed using electrode materials that exhibit high energy densities and consistency. In this work, NiCo2S4@NiCo2O4 core@shell nanoneedle-like nanostructures (NCS@NCO/rGO) are synthesized over the rGO sheet using a new and easy hydrothermal approach. Electrolyte transport and sulfur incorporation during charge–discharge reactions are both made easier by the core@shell nanostructured arrays' large active surface area. The ternary electrodes made of NCS@NCO/rGO have a rich mesoporous framework, a large surface area of 156.5 m2g−1, and an ideal distribution of pore sizes centered at 8.1 nm. An impressive specific capacitance of 2011 Fg−1 at 10 mV s−1 demonstrates the exceptional performance of the NCS@NCO/rGO ternary electrode. The ternary electrodes made of NCS@NCO and rGO have been shown to have remarkable cyclic stability in reports, maintaining 91 % of their capacity after 10,000 cycles. With an impressive power density of 983 Wkg−1 and an outstanding cycling durability of 98.8 % retention of the original capacitance after 10,000 cycles, the manufactured NCS@NCO/rGO//AC ACS displays a noticeable energy density of 68.5 Whkg−1. The mesoporous structure is excellent for increasing the characteristics of supercapacitor electrodes, as these astounding results can attest.

Lignosulfonate-Assisted Synthesis of Porous Carbon-Supported MnO2 Composites with Reinforced Interface Bonding for High-Performance Asymmetric Supercapacitors

Lignosulfonate-Assisted Synthesis of Porous Carbon-Supported MnO₂ Composites with Reinforced Interface Bonding for High-Performance Asymmetric Supercapacitors

Carbamide-mediated facile sol-gel synthesis of porous flower-like ZnCo2O4 microspheres for high-performance asymmetric coin cell supercapacitors

The design and development of ultrahigh-performance nanomaterials possessing novel characteristics are needed to achieve reliable energy storage performance. To satisfy the needs, diverse electrode materials are explored. Even though carbon-based materials hold high surface area and conductivity, their specific capacitance value fails to deliver high-performance applications. Therefore, pseudocapacitive transition metal oxide is adopted to overcome these issues. Among all Zinc Cobaltite, a binary transition metal oxide is widely explored owing to its fascinating electrochemical properties. As most of the synthesis of these kinds of materials requires the hydro/solvothermal method, herein, we have proposed the concept of a facile sol-gel method to prepare this class of materials by using Carbamide as both structure director and fuel to achieve the porous flower-like Zinc Cobaltite. The prepared material delivers the notable gravimetric specific capacitance of 513.3 F g−1. Owing to its unique morphology and porous structure, ion channelization is feasible, which will enhance the electrochemical reaction. Constructed asymmetric coin cell supercapacitor showed an extraordinary specific capacitance of 106.5 F g−1 and energy density of 56.2 Wh kg−1, demonstrating an impressive ability to retain 89.6 % of its capacitance after 4000 cycles at a current density of 6 A g−1. Due to the remarkable electrochemical behavior, this work can act as a guiding tool for designing efficient and cost-effective energy storage devices that will hold prodigious potential in commercial energy storage applications.

Facial design and synthesis of CoAl-LDH-doped MXene with nanosheet structure for high-performance asymmetric supercapacitors

Facial design and synthesis of CoAl-LDH-doped MXene with nanosheet structure for high-performance asymmetric supercapacitors

High-performance asymmetric supercapacitors assembled with novel disc-like MnCo2O4 microstructures as advanced cathode material

Herein, porous MnCo2O4 with disc-like (MnCo2O4-discs) and ring-like (MnCo2O4-rings) microstructures were respectively synthesized using an initial hydrothermal method at different temperatures and a calcination treatment in air. The electrochemical properties of these MnCo2O4 materials were investigated in three-electrode and two-electrode systems, and as such, MnCo2O4 presented a battery-like electrochemical response. The specific capacity of MnCo2O4-discs was determined to be 296.1C/g at 1 A/g, superior to 246.3C/g for MnCo2O4-rings. An asymmetric supercapacitor (ASC) was assembled with MnCo2O4 as the cathode and activated carbon (AC) as the anode to evaluate the potential for practical application. The MnCo2O4-discs//AC ASC exhibited an energy density (Ed) of 35.8 W h kg−1 at a power density (Pd) of 927.5 W kg−1. For the MnCo2O4-rings//AC ASC, an inferior Ed of 31.4 W h kg−1 under 890.9 W kg−1 was achieved. Furthermore, the two ASCs presented outstanding cyclic performance after 5000 cycles at 6 A/g. The exceptional properties of MnCo2O4 microstructures can be applied to the assembly of ASC devices, which can have promising potential for application in electrochemical energy storage. This synthetic method is straightforward, cost-effective, and can be extended to fabricate similar electrode materials with superior electrochemical performance.

Highly matched porous MXene anodes and graphene cathodes for high-performance aqueous asymmetric supercapacitors

Aqueous asymmetric supercapacitors (ASCs) provide promising prospects for electronic systems in the future that require high energy density, power density and cycling life, due to their advantages such as low cost, safe operation and environmental friendliness. However, developing well-matched anodes and cathodes with complementary potential windows and coordinated charge storage kinetics remains a significant challenge. Here, we constructed porous MXene- and graphene-based films with nitrogenous and phosphorous terminals as anodes and cathodes, respectively, alleviating the restacking of nanosheets, generating more electrochemical active sites and improving the electrolyte penetration. The assembled aqueous ASCs based on the porous MXene and graphene films could achieve an excellent energy density of 26.8 Wh kg−1 at 425 W kg−1, high rate performance, and remarkable cycling stability with 97.3 % retention after 20,000 cycles. This work demonstrates a novel concept to develop high-performance aqueous ASCs by surface engineering of two-dimensional porous electrodes with matched structural and electrochemical properties.

Binder free cobalt Manganese layered double hydroxide anode conjugated with bioderived rGO cathode for sustainable, high-performance asymmetric supercapacitors

Metal-organic frameworks (MOFs) possessmultifunctional characteristicssuch as tuneable pore structure and high specific surface area and are being designed with great interest to enhance the electrochemical properties of current energy storage devices. In this aspect, MOFs-derived layered double hydroxides (LDHs) are important candidates for advanced supercapacitors due to their high electrochemical activity and electric conductivity. Herein, we report synthesis of Cobalt Manganese layered double hydroxides (CoMn LDH) utilising Co MOF as a precursor via ion exchange method, while optimising the dosage of Mn to achieve the best possible structural outcome. The unique structure of CoMn LDH expressed high electrochemical parameters possessing specific capacitance of 1305F/g at 1 A/g. Afterwards, an asymmetric supercapacitor device was fabricated employing CoMn LDH as cathode and coffee grounds derived rGO (reduced graphene oxide) as anode. The as-prepared asymmetric supercapacitor device demonstrated a maximum working potential window of 1.2 V with energy and power density of 23.8 Wh/kg and 0.30 kW/Kg respectively. The device also exhibits superiorcoulombic efficiency and capacitance retention of 71.11 % and 82.7 % respectively over 3010 charge–discharge cycles that represents an effectiveapproach towards sustainable and effectiveenergy storage devices. In a nutshell, our study centred on adjusting composition, engineering structures, and assembling devices.

Fabrication of nickel foam/MXene/CoAl-layered double hydroxide by electrodeposition as electrode material for high-performance asymmetric supercapacitor

Layered double hydroxides (LDH) have become one of the highly promising electrode materials due to large specific area, excellent cycling stability and high energy density. However, the large internal resistance limits their applications in energy storage. The introduction of highly conductive materials is expected to solve this problem. In here, nickel foam (NF)/MXene/CoAl-LDH is prepared by electrodepositing CoAl-LDH on the surface of MXene-coated NF, and the effects of Co:Al ratio on the electrochemical properties are investigated in detail. The best electrochemical performance of the composite is obtained when Co:Al=2:1, with a specific capacitance of 646.7 F g−1 at 0.5 A g−1 and 450.8 F g−1 at 5 A g−1. Furthermore, the asymmetric supercapacitor is assembled with NF/MXene/CoAl-LDH as the positive electrode and activated carbon (AC) as the negative electrode. The voltage window of the device can reach 1.6 V. The specific capacitance of the device is 126.87 F g−1 at a current density of 0.5 A g−1. At the power density of 400 W kg−1, the energy density of 45.11 Wh kg−1 is provided. Even at the high power density of 4000 W kg−1, the energy density can still reach 17.88 Wh kg−1. After 5000 cycles at a current density of 5 A g−1, it still maintains a capacity retention rate of 92.9%. The asymmetric device with its high specific capacitance, long term stability and good power density and energy density has a great potential in energy storage applications.