High-performance Supercapacitor Applications Research Articles

Bifunctional heterostructure ZnWO4@ZnO nanocomposite for high-performance electrocatalysis and supercapacitor applications

Earth-abundant transition metal oxides (TMOs) represent a versatile class of electrode materials that excel in energy and environmental applications. Strategically incorporating additional metal oxides to form heterostructures significantly enhances electrical conductivity and cyclic stability, paving the way for better performance in energy storage and conversion technologies. In this study, we developed a ZnWO4@ZnO nanocomposite heterostructure using a straightforward solid-state synthesis method, positioning it as a bifunctional electroactive material for supercapacitor and catalytic applications. Importantly, the heterostructure’s increased surface area allows for more active sites for electrochemical reactions, which can boost current generation. The synergistic interaction between ZnO and ZnWO4 significantly enhances the electrochemical properties of the heterostructure, resulting in an impressive specific capacitance of 363 Fg−1 and exceptional cyclic stability over 10,000 charge–discharge cycles. These results underscore the potential of this material in energy storage and conversion technologies, making it a compelling candidate for high-performance supercapacitor and catalytic applications.

High-performance supercapacitors based on nonfunctionalized MXenes

MXenes are a group of two-dimensional materials that have attracted significant research interest worldwide due to their intriguing electrochemical characteristics for use in energy storage applications. However, the conductivity of MXenes and their performance as supercapacitor electrodes can be hindered by surface terminations. This study investigates the capability of non-functionalized MXenes, synthesized via chemical vapor deposition for use as supercapacitor electrodes, presenting a novel approach that explores the potential of these materials in energy storage applications. The synthesized MXenes are used to create supercapacitor electrodes, which are subjected to detailed analysis. The specific areal capacitance (SAC) of these electrodes (48.6 nm thick) is found to be 39.5 mFcm−2 at a scan rate of 2 mVs−1, equivalent to 928.4 Fg-1. Further investigation using galvanostatic charge-discharge (GCD) analysis reveals an initial specific gravimetric capacitance (SGC) of 442.6 Fg-1 at a current density of 0.5 Ag-1, which progressively decreases to 13.4 Fg-1 at 10 Ag-1. Remarkably, the MXene supercapacitors exhibit excellent stability over 10,000 charge-discharge cycles, retaining 85 % of their initial capacitance. These findings contribute to our understanding of MXene-based energy storage devices and pave the way for practical applications in high-performance supercapacitors.

2D/2D Nanocomposite of Graphene-Supported Cu-Doped Co-MOF for High-Performance Supercapacitor Applications

2D/2D Nanocomposite of Graphene-Supported Cu-Doped Co-MOF for High-Performance Supercapacitor Applications

Acid-etched halloysite and Co-Ni-B composites for high-performance supercapacitor application

The rational design and optimization of electrode materials can effectively enhance the electrochemical performance of supercapacitors. In this work, by utilizing the microemulsion method to combine the nanoflake-structured Co-Ni-B material with the highly porous hollow tubular structure of acid-etched halloysite (eHal), the stable and porous Co-Ni-B@eHal composites have been successfully synthesized. Simultaneously, the bimetallic composition in Co-Ni-B can offer a wealth of redox reactions, while the eHal tubes provide support and facilitate the ionic transport channels. The optimal electrode exhibits a high specific capacitance of 1534 F g−1 at a current density of 0.5 A g−1 and maintains 99.67 % of its initial specific capacitance at a current density of 20 A g−1, demonstrating excellent rate performance. Furthermore, it shows remarkable cyclic stability, retaining a specific capacitance of approximately 100 % after 60,000 cycles at a current density of 5 A g−1. The assembled Co-Ni-B@eHal-based asymmetric supercapacitor operates at a working voltage of 1.5 V and achieves a maximum energy density of 105.73 W h kg−1 at a power density of 375 W kg−1. These findings offer new insights into the development of bimetallic boride-based nanostructures and clay minerals in the field of electrochemical energy storage.

Novel NiCoMn MOFs/Ag citrate nanocomposites for high-performance asymmetric supercapacitor applications

Addressing the challenges posed by the global energy crisis, this research article explores the pivotal role of novel NiCoMn MOFs/Ag Citrate Nanocomposites in advancing high-performance asymmetric supercapacitor applications. This study delves into the synthesis of an efficient supercapacitor electrode material using a nanocomposite, denoted as MAx (where x = 1-3), combining NiCoMn metal-organic frameworks (MOFs, represented as M) with Ag-Citrate (notated as A). This synthesis employs an ultrasonication-assisted solvothermal approach. The XRD and SEM analyses authenticate the presence of anticipated phases and elements, revealing a seamless integration of the two components. Electrochemical assessments suggest that introducing Ag-citrate significantly augments the charge storage prowess of the nanocomposites. Specifically, the MA1 nanocomposite showcases a remarkable specific capacity of 762 C/g at 0.5 Ag−1, marking enhancements of 83 % and 10 % compared to pure Ag-citrate and unaltered MOFs, respectively. Furthermore, the asymmetric supercapacitor device based on this nanocomposite delivers optimal metrics: a specific capacity of 291.6 C/g at 2 Ag−1, an energy density of 61 Whkg−1, a power density of 1500 Wkg−1, a Coulombic efficiency of 98.5 %, and an enduring stability of 101 % over 4000 cycles. This exploration accentuates the significant promise of NiCoMn MOFs/Ag-Citrate nanocomposites as efficient, economical, and durable supercapacitors for a spectrum of energy storage needs.

Ternary MXene/PANI/ZnO-based composite with a built-in p–n heterojunction for high-performance supercapacitor applications

Abstract Two-dimensional (2D) Ti3C2T x MXene-based materials have attracted widespread attraction in the field of energy storage owing to their high conductivity and accordion-like structure. However, challenges such as restacking and oxidative degradation of the Ti3C2T x MXene structure lead to poor stability, low conductivity, low specific capacitance and, consequently, a low specific energy, hindering their extensive adoption at an industrial scale. In this study, a ternary MXene/polyaniline (PANI)/ZnO (MPZ) composite has been synthesized via surface engineering of two-dimensional (2D) MXene using one-dimensional (1D) PANI nanowires and ZnO nanoparticles to enhance its specific energy and stability while sustaining its specific power. 1D PANI nanowires and ZnO nanoparticles act as spacers to prevent restacking, while also exposing the suppressed redox active sites of 2D MXene and preventing it from being oxidized by forming a porous conductive network all over the surface of the MXene. PANI and ZnO also provide additional electroactive redox sites by forming p–n heterojunctions, thus enhancing faradaic redox reactions and the specific capacitance of the MPZ composite. As a result, the overall electrochemical performance and stability of the ternary MPZ composite are enhanced due to the synergistic interactions among the individual components within the ternary MPZ composite. At a low current density of 0.1 A g−1, the ternary MPZ composite exhibited a maximum specific capacitance of 651.96 F g−1 and a highest specific energy of 32.59 Wh Kg−1 while maintaining a specific power of 60 W Kg−1 as compared to MXene and binary MP composite. Furthermore, it showcased exceptional cyclic stability over 10 000 cycles with 94.75% and 92.95% capacitive retention at 0.6 A g−1 current density and 40 mV s−1 scan rate, respectively. Thus, this current study highlights an effective strategy to enhance the specific energy of MXene-based supercapacitors through surface engineering and the construction of p–n heterojunctions within the composite.

Facile synthesis and first principles calculations of Li-MoS2/rGO nanocomposite for high-performance supercapacitor applications

Two-dimensional (2D) nanostructured materials such as graphene oxide nanosheets and molybdenum disulfide (MoS2) are potential candidates for electrochemical energy storage applications. The layered structure of MoS2 makes it a promising active electrode material for supercapacitors. Lithium (Li) interacted with MoS2/reduced graphene oxide (Li-MoS2/rGO) nanocomposite has been synthesized in two steps using a sonochemical dispersion method, and a one-pot hydrothermal method resulting in few-layered MoS2/rGO nanosheets of 2D heterointerfaces. The Li-MoS2/rGO nanocomposite exhibits a high specific capacitance of 173.3 F g−1 at a current density of 1 A g−1. Furthermore, an asymmetric supercapacitor device fabricated with Li-MoS2/rGO achieves a good energy density of 10.6 Wh kg−1 at a power density of 686.3 W kg−1 and outstanding cycling stability with 81.2 % capacity retention over 10,000 cycles. The dispersion of 2D-MoS2 in water is due to the strong electrostatic interface. The structural and electronic properties are theoretically calculated for pristine and Li-interacted MoS2/rGO heterostructure using density functional theory. A comparison of the density of states plots of the two heterostructures and the difference charge density plot of Li-MoS2/rGO heterostructure clearly brings out the importance of the presence of Li. A value of 64 μF cm−2 for the quantum capacitance for pristine MoS2/graphene heterostructure increases to a value 99 μF cm−2 corroborating the experimental observations and we assign this change to the transfer of charge from the Li atom to the outer S atoms in the MoS2/graphene heterostructure. This comprehensive approach, combining experimental synthesis with computational modelling, significantly advances the development and optimization of high-performance supercapacitor materials in the energy storage field. The Li-MoS2/rGO nanocomposite has excellent electrochemical specific capacitance and long-term cyclic stability and has been effectively used for supercapacitor applications with high electrochemical performance.

Preparation of Tectona grandis Leaves derived Activated Carbon for High-Performance Supercapacitor Application

In energy-based applications, biomass porous micro/nanostructures activated carbon materials are the significant candidates, because of their high specific surface area, superior electrical conductivity, affordability and environmental friendliness. In this work, the activated carbon was prepared from Tectona grandis leaves as a biomass, and thus activated by 25% K2CO3 solution. The prepared carbon was designated as TGLAC. Second carbon was prepared from TGLAC was doped with urea and named as N-doped TGLAC. The physico-chemical analytical methods were employed to access the phase structure, bonding nature and morphological properties of the freshly prepared activated carbon material. Three electrode systems were utilized to estimate the supercapacitor features in 1 M Na2SO4 electrolyte. The prepared activated carbon electrode provides a specific capacitance of 371 F g–1 at 1 A g–1 and a 62% rate capability at 5 A g–1. It retains 94% of its initial capacitance during the cyclic stability analysis at 5 A g–1 over 5,000 cycles. This study demonstrates that carbon based materials obtained from sustainable waste biomass can exhibit favourable electrochemical performance in energy applications, providing a clear and feasible synthetic approach and strategy for their utilization.

Food waste-derived activated carbon for supercapacitors

This research investigates the utilization of activated carbon synthesized from food waste biomass, specifically, peels of orange, apple, cucumber, and onion, as electrode materials for high-performance supercapacitor applications. The peels were first pre-carbonized at 600 °C and then activated at 700 °C with KOH. The research involved developing a supercapacitor using the synthesized activated carbon as the electrode material and 6 M KOH as the electrolyte. The results indicated that electrodes made from orange peel, apple peel, cucumber peel, and onion peel exhibited specific capacitances of 238.5 F/g, 201.2 F/g, 236.9 F/g, and 118.9 F/g, respectively, at a current density of 1 A/g. When the current density was increased to 2 A/g, the elec-trodes maintained up to 90% of their capacitance.

Solid-state synthesis of nickel selenide for high-performance supercapacitors

This study focuses on the synthesis and electrochemical characterization of nickel diselenide (NiSe2) as a promising electrode material for supercapacitors. NiSe2 was synthesized through a facile solid-state process involving the mixing of nickel acetylacetonate and selenous acid, followed by drying and sintering at 500 °C under inert conditions. The resulting NiSe2 exhibited a granular structure with worm-like surface architecture and particle size ranging from 20 to 100 nm. The electrochemical performance of NiSe2 was evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) in a 6 M KOH electrolyte. NiSe2 demonstrated a high specific capacitance of 744.7 F g−1 at a discharge rate of 1 A g−1, with an outstanding rate capability retaining the capacitance of 483.6 F g−1 at 10 A g−1, and exceptional long-term cycling stability. The kinetic analysis revealed that the energy storage mechanism in NiSe2 primarily involves diffusion-controlled charge storage. EIS further confirmed the favorable charge transfer properties of the NiSe2 electrode. Overall, NiSe2 synthesized via the proposed method shows great promise for application in high-performance supercapacitors.

Capacity augmentation strategy in α-Fe2O3 nanoparticles through multifaceted structural and electrochemical analyses

Hematite (α-Fe₂O₃) has garnered significant research interest for supercapacitor applications, but capacity fading and limited cyclic life remain serious challenges. In this context, the present research provides a comprehensive study of the factors that significantly impact charge kinetics within the electrode and at the solid/electrolyte interface. By integrating structural and electrochemical analyses, this study offers an effective strategy to enhance the capacity of α-Fe₂O₃ nanoparticles through rigorous scientific analysis and identification of various qualitative and quantitative factors that influence charge storage capacity. A simple one-step co-precipitation method was adopted to synthesize porous α-Fe₂O₃ nanoparticles. The quantitative analysis of charge kinetics demonstrated the domination of diffusion-controlled charge storage as the main contributor to the total charge storage. The α-Fe₂O₃ nanoparticles-based electrode delivered a high energy density of 24.6 Wh kg⁻1 at an impressive power density of 478.7 W kg⁻1. Additionally, it displayed a capacity retention of 79 % over 10,000 cycle operations. The choice of electrode material and the superior porous nanoarchitecture have proven to be advantageous for high-performance supercapacitor applications, offering fast electron/ion transport.

Electrochemical evaluation of ZnO and PAN-based carbon nanofibers composite for high-performance supercapacitor application

Electrochemical evaluation of ZnO and PAN-based carbon nanofibers composite for high-performance supercapacitor application

MnCo2O4 nanospheres entrapped in g-C3N4 network for High-Performance supercapacitor applications

MnCo2O4 nanospheres were embedded in a g-C3N4 network using the solvothermal method with ethylene glycol as the solvent. SEM confirmed the uniformity of the MnCo2O4/g-C3N4 nanospheres, while XRD and XPS were used for structural and elemental analysis, including metal oxidation states. BET analysis revealed the surface area and porosity, while TEM analysis provided information on the interplanar spacing and morphology. Electrochemical evaluations using CV, GCD, and EIS demonstrated that the 2D g-C3N4 nanosheets interwoven with MnCo2O4 nanospheres have excellent specific capacities (654 Fg−1 at 2 Ag−1) and power densities (1521.2 W/kg at 7 Ag−1). The electrode material shows superior cyclic stability with 92.3 % capacitance retention after 5000 cycles.

Polar phonons features and intrinsic dielectric properties of RE2CoMnO6 (RE = Tb, Dy, Ho, Tm and Yb) double perovskites

RE-based double perovskite (DP) oxides of the RE₂TMTM'O₆ family exhibit intriguing magnetodielectric (MD) properties and magnetocaloric effects (MCEs), making them promising candidates for applications in high-performance supercapacitors, memories, spintronic devices, and cryogenic magnetic refrigeration. This paper addresses the vibrational properties of RE2CoMnO6 (RE = Tb, Dy, Ho, Tm, and Yb) ceramics for the first time using infrared reflectance spectroscopy. The dielectric merit factors in the microwave (MW) range, including the quality factor (Qu) and the static dielectric constant (ɛ0), were estimated. It was observed that the intrinsic dielectric constants decrease from approximately 26.2 to 14.4 as the rare earth ionic radius decreases. The mean values of these compounds suggest their suitability for applications in MW circuitry devices.

MOF-on-MOF Derived Co2P/Ni2P Heterostructures for High-Performance Supercapacitors.

Metal-organic frameworks (MOFs) have been widely used as versatile precursors to fabricate functional nanomaterials with well-defined structures for various applications. Herein, the presynthesized Ni-MOF nanosheets were grown on a Ni foam (NF) substrate, which then guided the nucleation and further growth of Prussian blue analogues (PBA) nanocubes to form MOF-on-MOF of the PBA/Ni-MOF film. This film was subsequently converted into a Co2P/Ni2P heterostructure. The NF-supported Co2P/Ni2P composites exhibited excellent supercapacitor performance, delivering a high specific capacity of 5124.2 mF cm-2 at 1 mA cm-2 and a remarkable capacity retention of 80.69% after 3000 cycles at 10 mA cm-2. An asymmetric supercapacitor assembled using Co2P/Ni2P/NF as the cathode and activated carbon as the anode yielded a maximum energy density of 0.34 mWh cm-2 at a power density of 1.50 mW cm-2. The enhanced supercapacitor performance is attributed to the synergistic effects of the Ni2P and Co2P components with multiple valence states as well as the unique hierarchical structure, which provides efficient pathways for electron and ion transport while mitigating volume expansion during energy storage. This synthetic strategy demonstrates an effective approach to fabricate phosphide-based hybrid materials for high-performance supercapacitor applications.

MoS2/Yb, Er-doped CeO2 composite synthesized by hydrothermal method for high-performance supercapacitor applications

MoS2/Yb, Er-doped CeO2 composite synthesized by hydrothermal method for high-performance supercapacitor applications

Preparation of N and S heteroatoms doped activated carbon from stalks of Gossypium hirsutum L. flower for high-performance symmetric supercapacitor application

Preparation of N and S heteroatoms doped activated carbon from stalks of Gossypium hirsutum L. flower for high-performance symmetric supercapacitor application

One-dimensional lepidocrocite titania mesoparticles integrated with activated carbon for high-performance supercapacitor applications

Herein, we mix titania-based, TiO2, porous mesostructured, comprised of one-dimensional lepidocrocite nanofilaments, 1DLs, ≈ 5 × 7 Å2 in cross-section, with activated carbon, AC, to create unique composite structures with exceptional electrochemical properties. The synthesis method is facile, cost-effective, and scalable. While the porous mesoparticles, PMs, possess excellent protonic conductivity and exhibit enhanced faradic behavior in acidic aqueous media, their low electronic conductivity restricts their power output. The problem is solved by mixing the PMs with AC powders with various loadings. Electrolytes used were sulfuric acid, H2SO4, potassium hydroxide, KOH, lithium and Na-sulphates. The best PM loading was found to be 25 wt%. The resulting composite exhibits a specific capacitance (capacity) of 1024 Fg−1 (554 mAhg−1) at a 2 mVs−1 scan rate, with 97 % cyclic stability over 10,000 cycles when the electrolyte was 1 M H2SO4. Upon integration into a symmetrical device, the composite exhibited a specific energy of 135 Whkg−1 at 0.5 Ag−1. Further, it demonstrated a peak specific power of 18 kWkg−1, while retaining a specific energy of 54 Whkg−1 at 5 Ag−1. Notably, following 100,000 cycles at 1 Ag−1, the symmetrical cell sustained approximately 50 % of its initial specific capacitance. Subsequently, a 24 h self-discharge test revealed a decrease in cell voltage from 1.95 V to 0.48 V, thereby highlighting the potential suitability of these supercapacitors for short-term energy storage applications.

Synergistic Schottky contacts & diatomic doping in Cr/P-MoS2@Ti3C2Tx with boosted energy storage performance

Molybdenum disulfide (MoS2), despite its promising attributes, suffers from low conductivity and aggregation. Herein, we introduce a novel approach that integrates Schottky contacts with Cr/P diatomic doping in MoS2@Ti3C2Tx, significantly enhancing its performance. The Schottky contacts effectively suppress aggregation and accelerate interfacial charge transfer, while Cr/P doping boosts conductivity, active sites, and stability. As a result, the Cr/P-MoS2@Ti3C2Tx electrode exhibits a specific capacitance of 650 F g-1 at 1 A g-1, which is fourfold higher than that of pristine MoS2. When assembled into an asymmetric supercapacitor (Cr/P-MoS2@Ti3C2Tx//AC ASC), the device achieves a peak energy density of 32 Wh kg-1 at 303 W kg-1, maintaining 85% capacitance retention after 10,000 cycles with an impressive coulombic efficiency of 97%. Furthermore, the density functional theory (DFT) calculations validate the beneficial effects of Schottky contacts and diatomic doping on the improved energy storage performance of Cr/P-MoS2@Ti3C2Tx. This work demonstrates the promising potential of the material for applications in high-performance supercapacitors (SCs).

Marigold flower-like structured battery-type Cu2O/Co(OH)2 composite electrode material for high-performance supercapacitors

Addressing the limitations of individual Cu2O and Co(OH)2 components, this study aims to develop a high-performance supercapacitor electrode by synergistically combining these materials. A composite electrode material of Cu2O/Co(OH)2 was effectively synthesized on nickel foam via a facile hydrothermal method for supercapacitor applications. The as-fabricated Cu2O/Co(OH)2 composite electrode exhibits a hierarchical marigold flower-like morphology that comprises of many interspersed nanoflakes. This unique morphology offers several advantages, including increased surface area, abundant electroactive sites, and enhanced electrolyte accessibility, all of which contribute to superior electrochemical performance. The Cu2O/Co(OH)2 electrode demonstrates exceptional battery-type supercapacitor behavior, characterized by prominent redox peaks in cyclic voltammetry curves and a well-defined potential plateau during galvanostatic charge-discharge measurements. The electrode delivers an outstanding specific capacitance of 90.21 mA h g⁻1 at a current density of 1.25 A g⁻1 and retains a remarkable 81.91 % capacitance at a high current density of 12.5 A g⁻1. Furthermore, the electrode exhibits impressive cycling stability, maintaining approximately 107.84 % of its initial specific capacity value after 200 cycles at 7.5 A g⁻1. Electrochemical impedance spectroscopy measurements reveal low solution resistance and charge-transfer resistance, signifying efficient charge-transfer kinetics within the electrode. These findings highlight the potential of Cu2O/Co(OH)2 composite electrodes as promising candidates for high-performance supercapacitor applications.