Performance Supercapacitors Research Articles

Incorporating Ag into Nd-Succinate MOF: Tunned electrochemical supercapacitor behaviour of Ag modified Nd-Succinate and electrochemical reaction mechanism

The electrode materials must be tailored to achieve higher energy and power densities and thus improve the supercapacitor's performance. This study explores the impact of incorporating Silver (Ag) into a Neodymium-Succinate Metal Organic Framework (Nd-Succinate) on supercapacitor behaviour. Initially, the Nd-Succinate MOF was characterized by structural, morphological, and spectroscopic characterizations. Subsequently, Ag/Nd-Succinate was synthesized and characterized. The electrochemical performance of Ag/Nd-Succinate was evaluated in a 6 M KOH electrolyte; the results indicated a significant enhancement in supercapacitor performance upon incorporating Ag into parent Nd-Succinate. From galvanostatic Charge-Discharge cycles (GCD), the capacitance for Ag/Nd-Succinate was determined to be 1389 F/g, i.e., 42 % higher than that of bare Nd-Succinate which was measured at 978 F/g. at a current density of 1.25 A/g. Ag/Nd-Succinate showcased an 89 % retention value for multiple retention cycles, slightly higher than the retention value obtained (84 %) for Nd-Succinate. The results of electrochemical experiments (Cyclic voltammetry (CV) and Electrochemical Impedance Spectra (EIS)) provided information about the nature of electron transfer and capacitance enhancement upon the introduction of Ag into Nd-Succinate. These findings provide valuable information on modifying MOFs and introducing metal that will help produce high-performance supercapacitor electrodes.

Probing the layer-dependent behavior of electronic properties and quantum capacitance in 2H MoS2: A computational analysis with emphasis on mechanical stability

The quest for clean, sustainable energy sources was prompted by the fast depletion of fossil fuels and the world's expanding energy requirements. To store renewable energy, it is important that effective energy storage devices such as supercapacitor (SCs) be manufactured. SCs offer a promising avenue for fast-charging, energy storage, and long-life cycles but maximizing their energy density remains a problem. This study theoretically explores the intrinsic Quantum capacitance (Cq) of MoS2 in the 2H phase with a few number of layers and how factors like electronic structure and density of states influence its capacitance behavior. In the present work, the first principles analysis utilizing computational modelling with Density Functional Theory (DFT) has been employed to investigate the Cq and surface charge density (σ) of MoS2. By explaining the connection between MoS2's electrical and structural properties with its Cq, valuable insights for optimizing it's SC performance were obtained. Both the density of states (DOS) and the Cq increase with the number of layers. Among the observed structures the highest value of Cq is observed for the three layered structure of 2H–MoS2 (2H3L-MoS2) at +1 V which is 1615.14 μF cm−2. Investigating the mechanical stability of optimized structure (2H3L-MoS2), a high Young's modulus of 180.46 GPa is observed for 2H3L structure. Hence, 2H-phase of MoS2 can be used as an excellent anode material for asymmetric SCs and flexible electronic devices.

Construction of ultra-thin NiMo3S4 nanosheet sphere electrode for high-performance hybrid supercapacitor

The construction of electrode materials with rational morphology and structure based on bimetallic sulfides is crucial to improve the performance of supercapacitors. Ultra-thin three-dimensional nickel molybdenum sulfide nanosheet spheres (NiMo3S4 NSSs) are grown on nickel foam (NF) using a one-step hydrothermal synthesis. NiMo3S4 NSSs have a diameter of ∼ 5 μm and nanosheet thickness of 200 nm. The effects of increasing the hydrothermal synthesis time and molar concentration ratios of Ni2+ to MoO42- on the morphologies of the NiMo3S4 are investigated. Due to the synergistic effect of NiMo3S4 NSSs and bimetallic ions which can provide a larger solution contact areas and improve the redox activity, the electrode exhibits good electrochemical properties. The specific capacity of NiMo3S4 NSSs/NF electrode can reach 1002.4 C/g (1 A/g). After being assembled into a hybrid supercapacitor (HSC) with activated carbon (AC), the energy density can reach 72.1 Wh/kg at the power density of 749.9 W/kg. In addition, the HSC shows an excellent stability of 89 % after 10, 000 charge-discharge cycles (10 A/g).

Improved supercapacitive performance based on novel RuO2/SiO2 nanocomposites

In this work, RuO2/SiO2 nanocomposites are synthesized by dispersing RuO2 in SiO2 nanoparticles with hydrothermal method. The morphology and structure of the composites are comprehensively characterized and confirmed that the agglomeration of RuO2 is reduced and their dispersion is enhanced. Their supercapacitive performances are evaluated by electrochemical tests. It shows that the RuO2/SiO2 nanocomposite provides a specific capacitance of 1785.1 F g−1 at 1 A g−1 and maintains 90.7 % capacitance retention after 10,000 cycles. Asymmetric supercapacitors are prepared with the RuO2/SiO2 composite as the positive electrode and conductive carbon as the negative electrode. The specific capacitance is 159.4 F g−1 at 0.05 A g−1. An energy density of 14.2 Wh kg−1 is obtained at a power density of 79.9 W kg−1. Through the doping of SiO2, RuO2 grows dispersedly outside SiO2, and thus the agglomeration of RuO2 is weakened, and both proton diffusion and electron transfer are effectively enhanced, and the electrochemical properties are improved significantly, showing great potential for commercial applications.

Engineering a vanadium-incorporated MoS2-based mixed metal dichalcogenide system for improved supercapacitor performance

In this study, we developed a mixed metal dichalcogenide system of molybdenum‑vanadium disulfide with the chemical formula Mo1-xVxS2, where x = 0.3, 0.5, and 0.7, corresponding to Mo:V ratios of 70:30, 50:50, and 30:70 using a facile one-pot hydrothermal method. This mixed metal structure is expected to influence both the basal plane and the edge plane towards engineering the active sites in the resulting system forming xMon+-yV4+-zS2− network, which is a crucial for its improved electrochemical performance. Structural studies confirmed the emergence of structural distortion in the system due to the difference in the ionic sizes of Mo and V ions, leading to strain in the lattices. Furthermore, electron microscopic analysis revealed the formation of aggregated nano-petals for bare MoS2, while these petals self-assembled to form flower-like microspheres upon the introduction of V in the mixed metal (Mo1-xVxS2) systems. Consequently, the Mo0.5V0.5S2 delivered a specific capacitance of 492.2 F g−1 at 1 A g−1 with substantial capacitance retention of 94 % up to 3000 cycles, which is twofold higher compared to bare MoS2. Moreover, the fabricated symmetric device achieved an energy density of 19.5 Wh kg−1 and a maximum power density of 9000 W kg−1 with capacitance retention of 92.8 and 86.3 % after 5000 and 10,000 charge/discharge cycles, respectively.

Self-doped N, P, O heteroatoms carbon nano-hollow-fiber derived aromatic bio-organic for advanced gravi-volumetric supercapacitors

Abstract The combination of heteroatoms self-doping and nano-hierarchical-pore structure is essential in improving the physicochemical performance of gravi-volumetric scale supercapacitors based on biomass-derived carbon. Herein, this study used aromatic bio-organic waste from nutmeg leaves (Myristica fragrans Houtt) as raw materials due to their abundant dopant and high-potential unique nano-pore structure. A series of novel treatments were carried out using KOH immersion approach and bi-atmospheric (in N2 and CO2) pyrolysis to ensure the presence of rich heteroatoms and a defined pore structure. The results showed that KOH ratio in bi-atmospheric pyrolysis played an important role in the production of self-dopant N, O, and P. In addition, significant morphological changes were observed after the production process. The optimized material prepared at a ratio of 500 mmol g−1 showed rich heteroatoms dopant with values of 19.53%, 15.81%, and 3.01% for N, P, and O, respectively. The surface transformation of the products showed a unique structure of nano-hollow-fiber with a size of 8–12 nm size and a well-matched micro-mesopores ratio (4:1). In the 2E-symmetric system, the working electrode exhibited a high gravimetric capacitance of 235 F g−1 at 1 A g−1 and 210 F g−1 at 10 A g−1 (in H2SO4 electrolyte). The resulting energy output was relatively high at 32.64 Wh kg−1 with increased power density (218 W kg−1), coulombic efficiency (92.67%), and capacitance retention (89.78%). The findings also showed that the products obtained had a volumetric capacitance of 256.30 F cm−3 and volumetric energy of 35.00 Wh l−1. Based on these results, the selection of natural materials as well as the application of KOH immersion approach and bi-atmospheric pyrolysis produced natural self-doped N, O, P carbon nano-hollow-fiber for boosting the gravi-volumetric behavior of supercapacitors.

Sequential growth controlled copper vanadate nanopebbles embedded thin films: Electrode to asymmetric supercapacitive device assembly

Supercapacitor performance critically relies on the design of electrodes with both superior electrochemical and mechanical properties. In this study, we present a cost-effective and scalable approach for the synthesis of copper vanadate (Cu3V2O8) nanopebbles integrated into a thin film, tailored for supercapacitor applications. The synthesis was accomplished using the successive ionic layer adsorption and reaction (SILAR) method, which enabled precise control over the deposition of Cu3V2O8 on a stainless steel (SS) substrate. Detailed structural, morphological, and elemental characterizations confirm the successful formation and reveal critical insights into the chemical bonding and oxidation state at material. The supercapacitive performance of Cu3V2O8 electrode has been evaluated in an aqueous NaClO4 electrolyte to assess pseudocapacitive behavior. The Cu3V2O8 electrode exhibited a specific capacitance of 443 F g−1 at 5 mV s−1 scan rate. Additionally, liquid configured an asymmetric device was designed using Multiwalled carbon nanotubes (MWCNT) combined with Cu3V2O8, yielding a specific capacitance of 116 F g−1 at 5 mV s−1 with an energy density of 8.43 Wh kg−1 and a power density of 345.4 W kg−1, while maintaining capacitance retention of 76 % even after 4000 cycles as stability test. This work highlights the potential of Cu3V2O8 based materials for excellent performance of new avenues for energy storage.

Impact of CNT assimilation on binary MoO2/MoS2 hybrid for enhanced cyclic stability during charging-discharging process

Cyclic stability is a crucial metric for assessing the service lifespan of supercapacitors, as it determines the retention capacity of the electrode material. This study demonstrates the significant impact of Carbon Nanotubes (CNT) on enhancing the cyclic stability of a binary hybrid MoO2/MoS2 (MOS) electrode material, thereby improving supercapacitor performance and durability. The combination of MoO2 and MoS2 enhances capacitance due to their high surface area and electrical conductivity. Introducing CNTs into MOS significantly enhances cyclic stability and provides a crucial pathway for electrolyte ions during charging-discharging cycles, despite a minor compromise in conductivity and energy efficiency. This trade-off is justified by the substantial improvement in overall performance and durability. The materials were synthesized and deposited on Nickel foam via a hydrothermal route without any binding agent. Electrochemical tests showed specific capacitances of 2617 F/g for MOS and 2052 F/g for MOSC at a current density of 1 A/g. The MOSC system exhibited a 41.4 % increase in cyclic stability after 2000 cycles. Additionally, a symmetric coin cell device fabricated with the MOSC material demonstrated a maximum energy density of 153.41 mWh/kg and a power density of 3 kW/kg at a current density of 0.05 A/g, with a capacitive retention of 74.05 %. This underscores the potential of MOSC as a scalable electrode material for industrial energy storage applications.

Optimized energy storage with hydrothermally synthesized metal sulfide nanocomposite electrodes

Supercapacitors exhibit impressive energy storage capabilities, providing high power density and quick charge/discharge cycles across various applications, including electronics and renewable energy systems. Molybdenum disulfide (MoS2) plays a crucial role in enhancing supercapacitor performance through its high surface area, conductivity, and electrochemical stability. Recent reports have shown that manipulating phase transitions and incorporating dopants or substitutions can significantly enhance the performance of 2D materials. The present study investigated the influence of tungsten substitution on the phase changes and electrochemical properties of MoS2. The hydrothermal synthesis process involved the substitution of tungsten with different concentration, leading to a notable phase change from 2 H to 1 T, as confirmed by X-ray diffraction (XRD) analysis. Morphological studies using scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) revealed modifications in the morphological structure. The electrochemical performance of pristine MoS2 and MoS2/WS2 composites were evaluated using cyclic voltammetry (CV), chronopotentiometry (CP), and electrochemical impedance spectroscopy (EIS). The determined specific capacitances of MoS2/WS2 composites exhibited higher values compared to pristine MoS2. Specifically, the sample with 15 mol% tungsten addition demonstrated a maximum specific capacitance of 333 F g−1, surpassing that of pristine MoS2 and other samples at a current density of 1 A g−1. This research provides valuable insights into the phase-dependent electrochemical behaviour of MoS2 with tungsten substitution, offering a better understanding of its potential for applications in high-performance energy storage devices.

Combined experimental and density functional theory approaches to address different mechanisms of nitrogen and sulfur doping on the enhancement of capacitive performance of hierarchical porous biochars

Activated carbon derived from biomass as hierarchical porous biochars (HPB) has been developed as electrode materials for supercapacitors. Nitrogen is known as the doping element that enhances quantum capacitance, but the mechanisms of sulfur doping on the quantum capacitance enhancement remain ambiguous. In this study, conventional approaches to assess the characteristics and capacitive performance of biochars were combined with density functional theory (DFT) calculations to assess different mechanisms of nitrogen and sulfur doping. The Bbiochar samples were prepared from the pyrolyzed fish bone powder at 800 °C without additional doping possessed a specific capacitance of 240 F g−1 at 1 A/g within 1 M H2SO4. Interestingly, additional nitrogen doping through urea mixing and additional sulfur doping through thiosulfate mixing prior to the pyrolysis enhanced the specific capacitance of biochar samples to exceed 400 F g−1 under the same condition. The urea mixed sample possessed low porosity but high charge transfer resistance, while the thiosulfate mixed sample possessed high porosity but low charge transfer resistance. The different underlying mechanisms were discussed through DFT calculations on graphene models designed based on the x-ray photoelectron spectroscopy (XPS) results. Nitrogen-doped configurations with topological defects mainly stored charge at the dangling atoms and possessed a relatively high quantum capacitance. Meanwhile, doped configurations of oxidized sulfur groups required relatively low formation energy and possessed large bond dipoles, corresponding to larger pore size and surface area of the thiosulfate mixed biochars. Understanding the contrary between effects of nitrogen and sulfur doping could resolve the bottleneck on enhancing the performance of electronic double layer supercapacitors.

The role of polymer gel electrolyte infiltration for enhancement of capacitance and cycle stability

With the increasing application of electronic materials in various fields such as flexible electronic textiles, wearable and portable gadgets, aerospace and aircraft systems etc., the demand for clean high-power energy storage devices is also increasing rapidly. To date, the application of market available supercapacitors has not met the energy expectations in the range of market leading Li-ion batteries (LIBs) due to their unreliable mechanical flexibility, electrolyte leakage, low voltage application, low capacity, low cycle stability and moderate rate-capability. Inappropriate utilization of the maximum porosity of the electrode material and inefficient activities of the electrode/electrolyte interface are major challenges for present supercapacitor development. In this work, for the first time, the role of polymer gel electrolyte infiltration to improve the electrochemical performance of a supercapacitor has been explicitly studied and investigated. It has been observed that 1-Ethyl-3- Methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM][TFSI] ionic liquid electrolyte embedded in Polypropylene Carbonate (PPC) and Polycarbonate (PC) polymer matrix polymer gel electrolyte (PGE) showed excellent supercapacitive performance at high voltage window 2.6 V by delivering maximum total capacitance of 5.81 F and maximum energy density 10.9 Wh kg-1 at 30 mA current (0.06 A g-1). Regular infiltration of the polymer gel electrolyte inside the electrode material is also observed during long cycle operation of 10,000 cycles. Infiltration of electrolyte ions into the pores of electrode materials plays a significant role in increasing capacitance and cycle Stability. These results highlight the potential of this novel high-voltage polymer gel electrolyte for future high-power energy storage device applications.

Core-shell structured MgCo2O4@Ni(OH)2 nanorods as electrode materials for high-performance asymmetric supercapacitors

In the field of energy storage, supercapacitors have received extensive attention in recent years. However, achieving the expected electrochemical performance and energy density of supercapacitors is still a huge challenge. The design and synthesis of binder-free composite electrode with core–shell structure is an effective strategy to improve the electrochemical performance of supercapacitors. In this paper, a heterogeneous core–shell structured and binder-free electrode material MgCo2O4@Ni(OH)2 (MCO@NH) grown on nickel foam (NF) is prepared by a simple hydrothermal and oil bath method. The unique core–shell structure makes the MCO@NH have a large specific surface area, which provides abundant active sites for ion transport and storage, thereby improving the electrochemical performance. The MCO@NH/NF nanocomposite demonstrates a high specific capacitance (Cs) of 1583 F g−1 at 1 A/g. A solid-state asymmetric supercapacitor (ASC) assembled with MCO@NH/NF and active carbon (AC) exhibits excellent energy density (45 Wh kg−1 at 457.5 W kg−1) and outstanding capacitance (89.51 %) and coulombic efficiency (97.8 %) after 12,000 cycles, evidencing its good operation stability and potential practical applications. Therefore, the prepared core–shell MCO@NH/NF electrode can be a promising candidate for energy storage devices.

One-step microwave synthesis of in situ grown NiSe microdendrite arrays on Ni foam for high-performance supercapacitors

The strategic design of in situ grown nanomaterials with microdendrite morphology to enhance supercapacitor performance has become a significant research focus in the field of renewable energy storage. This study explores an innovative one-step microwave technique for producing different NiSe microdendrite arrays that are grown in situ on Ni foam (NF) substrates. In this process, Ni foam serves dual roles as a Ni source and a structural framework. At a current density of 0.6 A g−1, NiSe microdendrite arrays that were synthesized demonstrate a capacity of 261.1 mAh·g−1, surpassing that of the majority of traditional pseudocapacitive materials. Furthermore, the effect of the solvent, Se powder dosage, and microwave reaction parameters on the micromorphology and electrochemical properties of NiSe is comprehensively examined. Furthermore, the supercapacitor device featuring a positive electrode composed of NiSe microdendrite arrays and a negative electrode constructed from activated carbon (AC) exhibits a broad voltage range of 1.7 V. It also achieves a peak energy density of 50.29 Wh·Kg−1 at power density of 847.98 W kg−1, suggesting a promising application prospect.

Microwave-assisted synthesis of perovskite hydroxide-derived Co3O4/SnO2/reduced graphene oxide nanocomposites for advanced hybrid supercapacitor devices

The current article reports a facile, ultrafast, and cost-effective, solid-state microwave (MW) synthetic route for the conversion of perovskite hydroxide (CoSn(OH)6) to crystalline metal oxides (Co3O4 and SnO2) with the help of reduced graphene oxide (rGO) nanosheets. In a domestic MW oven, the Co3O4/SnO2/rGO (CSO-rGO) nanocomposite was synthesized within a quick reaction time of only 30 s. The study deeply focused on analyzing the surface morphology, metal oxide attachment on the surfaces of rGO nanosheets, the specific surface area, and the electrochemical performance of supercapacitor devices from the CSO-rGO nanocomposite. As a positive electrode for supercapacitors, the synthesized hybrid electrode displayed a good capacity (146.4C/g) and enhanced cycling stability (103.2 % after 15,000 cycles). Moreover, the corresponding aqueous hybrid supercapacitor device with MW-synthesized rGO as a negative electrode displayed a maximum energy density of 27 Wh/kg and promising cycling stability of 102.4 % after 10,000 cycles. As a whole, compared to the common time-consuming synthetic approaches, the MW-assisted synthetic approach is highly beneficial in terms of short reaction time, cost-effectiveness, and straightforwardness. The MW synthesis methodology employed in this study can be utilized for analogous composite electrodes that incorporate other layered conductive architectures in addition to metal oxides.

Enhanced Supercapacitor and Cycle-Life Performance: Self-Supported Nanohybrid Electrodes of Hydrothermally Grown MnO2 Nanorods on Carbon Nanotubes in Neutral Electrolyte.

Efficient and sustainable energy storage remains a critical challenge in the advancement of energy technologies. This study presents the fabrication and electrochemical evaluation of a self-supporting electrode material composed of MnO2 nanorods grown directly on a carbon paper and carbon nanotube (CNT) substrate using a hydrothermal method. The resulting CNT/MnO2 electrodes exhibit a unique structural architecture with a high surface area and a three-dimensional hierarchical arrangement, contributing to a substantial electrochemical surface area. Electrochemical testing reveals remarkable performance characteristics, including a specific capacitance of up to 316.5 F/g, which is 11 times greater than that of conventional CP/MnO2 electrodes. Moreover, the CNT/MnO2 electrodes demonstrate outstanding retention capacity, exhibiting a remarkable 165% increase over 10,000 cycles. Symmetric supercapacitor devices utilizing CNT/MnO2 electrodes maintain a large voltage window of 3 V and a specific capacitance as high as 200 F/g. These results underscore the potential of free-standing CNT/MnO2 electrodes to advance the development of high-performance supercapacitors, which can be crucial for efficient and sustainable energy storage solutions in various industrial and manufacturing applications.

Evolution of CuO bundles of nanowires by room temperature surface oxidation of electroplated Cu for high-performing energy storage device

In the present work, copper oxide bundles of nanowires (CuO BNWs) were synthesized by room-temperature surface oxidation of an electroplated Cu layer in an alkaline bath. The time-dependent morphological evolution of CuO BNWs is systematically achieved by varying surface oxidation times. The CuO BNWs provide a high surface area (19.12 m2/g) and have shown excellent supercapacitive performance with a specific capacitance of 509 F/g at 1 A/g current density owing to fast electron transfer paths offered by BNWs. The all-solid-state hybrid supercapacitor device (SS//Cu//CuO-BNWs//KOH-PVA//rGO) demonstrates a specific capacitance of 77.3 F/g and energy density of 22.57 Wh/kg at a power density of 1.29 kW/kg.

Utilization of copper chromite-reduced graphene oxide nanocomposite for the wastewater remediation and effective supercapacitive performance

This article has detailed the growth of virgin copper chromite nanoparticles (CuCr2O4 NPs) and reduced graphene oxide sheet (rGO)-based CuCr2O4 nanocomposite through the process of reflux condensation method and calcination process. When exposed to visible light, these two synthesized nanomaterials exhibit enhanced photocatalytic activity which helps in the degradation of organic dyes such as methylene blue. Numerous characterization methods, including FTIR, UV–visible analysis, and XRD, verify the creation of these nanomaterials. The CuCr2O4-rGO nanocomposite's semiconductor nature is confirmed by the band gap analysis using Tauc's formula. The CuCr2O4 NPs grown on the rGO surface have a dimension of 6 nm, according to the TEM study and particle distribution graph. To find the reason for the enhanced photo-activity, we have proposed a photocatalytic mechanism which is supported by photoluminescence result. Recyclability in five more cycles is used to measure the stability of the nanocomposite, and it is found that photocatalytic efficiency does not significantly decline up to five cycles. When exploring the CuCr2O4-rGO nanocomposite as a material for supercapacitor electrodes, it showcased a remarkable specific capacity of 681.43 F/g at 0.5 A g−1. Moreover, the CuCr2O4-rGO nanocomposite electrode displayed a long-term life cycle, retaining 93.8 % of its initial capacity after 1200 cycles, paired with a commendable Coulombic efficiency of 95.31 % and outstanding power and energy density of 1504 W/kg and 23.66 Wh/kg respectively.

Fabrication of oxygen-rich/nitrogen-doped hierarchical porous Ganoderma lucidum spore activated carbon for enhanced supercapacitor performance

Fabrication of oxygen-rich/nitrogen-doped hierarchical porous Ganoderma lucidum spore activated carbon for enhanced supercapacitor performance

Boosting supercapacitor performance synergistically with Bi2O3/MnO2:rGO nanocomposites and redox additive electrolyte

The contemporary surge in energy demand underscores the imperative for improvements in energy conversion and storage technologies. In response, supercapacitor devices were engineered using nanocomposites (NCs) of Bi2O3/MnO2:rGO (BMR), and their electrochemical performance was systematically documented. The BMR NCs were hydrothermally prepared and their physicochemical characteristics were analyzed. The working electrode was constructed employing BMR NCs, and tested in a three-electrode setup to explore its electrochemical properties using the aqueous electrolytes consisted of 1 M KOH and 0.1 M K4[Fe(CN)6] added 1 M KOH (referred as Redox additive electrolyte - RAE). BMR NCs loaded working electrode exhibited 1441.1 Fg−1 of specific capacitance at 5 mVs−1 in RAE. Subsequently, asymmetrical supercapacitor devices were assembled, incorporating a cathode comprised of BMR NCs modified Ni foam and rGO-loaded Ni foam as an anode. The supercapacitor performances were evaluated using KOH and RAE in a two-electrode setup. The BMR NCs loaded supercapacitors demonstrated 9.42 Whkg−1 and 2100 Wkg−1, of energy and power densities, respectively, in KOH. Obtained energy and power density values were improved to 16.08 Whkg−1 and 2800 Wkg−1, respectively, by the utilization of RAE. Since the synthesized BMR NCs exhibited superior performances in RAE, the suggested combination of BMR NCs and RAE emerged as a more promising option for energy storage applications in real-time.

Optimizing symmetric supercapacitor performance through rational design of Zr/Cu/Fe Oxide-Modified Poly(vinyl alcohol) hybrid nanofibers

Present work, ZrO2/CuO/PVA (ZC-PVA), ZrO2/Fe2O3/PVA (ZF-PVA) and ZrO2/CuO/Fe2O3/PVA (ZCF-PVA) nanofibers were synthesized by cost effective electrospinning method. The ZCF-PVA nanofiber prepared in this study were subjected to analysis using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) techniques, individually. XRD was employed to ascertain both the structure and crystallite size of the synthesized materials. SEM and FT-IR analysis were used to identify the morphology and functional groups present in the prepared ZC-PVA, ZF-PVA and ZCF-PVA nanofibers. XPS confirmed the surface elemental composition and oxidation states of Zr4+, Cu2+, and Fe3+ in ZCF-PVA nanofiber comprising ZrO2, CuO, and α-Fe2O3. In three electrode configuration ZCF-PVA nanofiber shows significantly higher specific capacitance of 824F/g at 1 A/g current density under 1 M KOH. The generation of synergic effect between multi valence oxidation states of mixed metal oxides and polymer (ZCF-PVA) enhances the capacitive behavior. The ZCF-PVA symmetric device exhibits 184F/g at 0.5 A/g current density with 91 % capacitance retention and 94 % of coulombic efficiency even after 5000 cycles at 3 A/g of current density.