Current Density Of 1Ag-1 Research Articles

Promising transition metal molybdate (TMM) single phase microstructures for asymmetric supercapacitor and photocatalytic applications

The increasing impact of worldwide energy challenges has sparked significant interest in developing multifunctional nanomaterials for energy and environmental applications. Among semiconductor photocatalysts, stable mixed metal molybdate materials have garnered much interest regarding energy storage and photocatalytic dye degradation. In this context, we have synthesized three different single-phase metal molybdates (NiMoO4, MnMoO4, and Fe2(MoO4)3) using the gel matrix method. XRD and Raman were executed to confirm phase formation of the acquired materials. Difference in surface morphology of synthesized transition metal molybdate powders was examined using SEM analysis. The energy-storing properties of synthesized transition metal molybdate powders were analyzed and compared using three and two electrode method. At a 1 Ag-1 current density, the as-synthesized NiMoO4, MnMoO4, and Fe2(MoO4)3 nanostructures exhibit specific capacitances of about 424.6, 325.5 and 157.8 Fg-1, respectively. Furthermore, the fabricated ASC device with NiMoO4 shows 41.6 Whkg-1 and 750 Wkg-1 as maximum energy and power density at 1 Ag-1, respectively. Meanwhile, photocatalytic methylene blue degradation was carried out using the as-synthesized materials as photocatalysts. The Fe2(MoO4)3 effectively decolourizes the dye with a maximum efficiency of 82.7 %, when compared to other two metal molybdate powders. Thus, the results show that the synthesized metal molybdates such as NiMoO4, and Fe2(MoO4)3 can act as potent electrode materials and efficient photocatalysts for energy storage and dye degradation applications when compared to MnMoO4.

High-capacity and fast-charging Al battery based on Cu/KB cathode

Rechargeable aluminum-ion batteries (RABs) are promising for energy storage due to their high theoretical energy density, but face challenges in cathode materials that match aluminum's capacity and stability. We propose copper (Cu) as an inexpensive and easily synthesized cathode material for RABs, using KetjenBlack (KB) as a carbon framework to enhance cycling stability by reducing structural damage. Key findings include: (1) Specific capacities of 793.5 mAhg-1 (charge) and 414.5 mAhg-1 (discharge) at 2 Ag-1 current density; (2) Good rate performance with a capacity maintained around 200 mAhg-1 at 12 Ag-1; (3) After 300 cycles at 2 Ag-1, discharge capacity stabilized at 225.1 mAhg-1. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) were used to analyze electrode changes and understand the Cu/KB||Al battery's energy storage mechanism. This study introduces a novel electrode material and proposes a carbon framework for enhancing RAB performance.

A Universal In-Situ Interfacial Growth Strategy for Various MXene-Based van der Waals Heterostructures with Uniform Heterointerfaces: The Efficient Conversion from 3D Composite to 2D Heterostructures.

Two-dimensional (2D) van der Waals heterostructures endow individual 2D material with the novel functional structures, intriguing compositions, and fantastic interfaces, which efficiently provide a feasible route to overcome the intrinsic limitations of single 2D components and embrace the distinct features of different materials. However, the construction of 2D heterostructures with uniform heterointerfaces still poses significant challenges. Herein, a universal in-situ interfacial growth strategy is designed to controllably prepare a series of MXene-based tin selenides/sulfides with 2D van der Waals homogeneous heterostructures. Molten salt etching by-products that are usually recognized as undesirable impurities, are reasonably utilized by us to efficiently transform into different 2D nanostructures via in-situ interfacial growth. The obtained MXene-based 2D heterostructures present sandwiched structures and lamellar interlacing networks with uniform heterointerfaces, which demonstrate the efficient conversion from 3D composite to 2D heterostructures. Such 2D heterostructures significantly enhance charge transfer efficiency, chemical reversibility, and overall structural stability in the electrochemical process. Taking 2D-SnSe2/MXene anode as a representative, it delivers outstanding lithium storage performance with large reversible capacities and ultrahigh capacity retention of over 97% after numerous cycles at 0.2, 1.0, and 10.0 Ag-1 current density, which suggests its tremendous application potential in lithium-ion batteries.

V-Doping Strategy Induces the Construction of the CoFe-LDHs/NF Electrodes with Higher Conductivity to Achieve Higher Energy Density for Advanced Energy Storage Devices.

Doping of metal ions shows promising potential in optimizing and modulating the electrical conductivity of layered double hydroxides (LDHs). However, there is still much room for improvement in common metal ions and conventional doping methods. In contrast to previous methodologies, a hollow triangular nanoflower structure of CoFeV-LDHs is devised, which is enriched with a greater number of oxygen vacancies. This resulted in a significant enhancement in the conductivity of the LDHs, leading to an increase in energy density following the appropriate doping of V. To investigate the impact of V-doping on the energy density of the LDHs, in situ XPS and in situ X-ray spectroscopy is employed. Regarding electrochemical performance, the CoFeV-LDHs/NF electrode with optimal doping ratio exhibited a specific capacitance of 881Fg-1 at a current density of 1Ag-1. The capacitance remained at 90.53% after 3000 cycles. In addition, the constructed battery-type supercapacitor CoFeV-LDHs/NF-2//AC exhibited an impressive energy density of 124.7Whkg-1 at a power density of 850Wkg-1 and capacitance remained almost unchanged at 95.2% after 3000 cycles. All the above demonstrates the great potential of V-doped LDHs and brings a new way for the subsequent research of LDHs.

Rice powder template for hausmannite Mn3O4 nanoparticles and its application to aqueous zinc ion battery.

In this study, a simple calcination route was adopted to prepare hausmannite Mn3O4 nanoparticles using rice powder as soft bio-template. Prepared Mn3O4 was characterized by Fourier Transform Infra-Red Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray microanalysis (EDX), Powder X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET) and Solid state UV-Vis spectroscopic techniques. Mn-O stretching in tetrahedral site was confirmed by FTIR and Raman spectra. % of Mn and O content supported Mn3O4 formation. The crystallinity and grain size was found to be 68.76% and 16.43 nm, respectively; tetragonal crystal system was also cleared by XRD. TEM clarified the planes of crystal formed which supported the XRD results and BET demonstrated mesoporous nature of prepared Mn3O4 having low pore volume. Low optical band gap of 3.24 eV of prepared Mn3O4 nanoparticles indicated semiconductor property and was used as cathode material to fabricate CR-2032 coin cell of Aqueous Rechargeable Zinc Ion Battery (ARZIB). A reversible cyclic voltammogram (CV) showed good zinc ion storage performance. Low cell resistance was confirmed by Electrochemical Impedance Spectroscopy (EIS). The coin cell delivered high specific discharge capacity of 240.75 mAhg-1 at 0.1 Ag-1 current density. The coulombic efficiency was found to be 99.98%. It also delivered excellent capacity retention 94.45% and 64.81% after 300 and 1000 charge-discharge cycles, respectively. This work offers a facile and cost effective approach for preparing cathode material of ARZIBs.

Porous cobalt phosphide nanoflakes supported on ordered mesoporous carbon for superior electrochemical performance supercapacitor and hydrogen evolution reaction

In this study, we synthesized cobalt phosphate flake-like nanostructures anchored to the OMC matrix using a simple and cost-effective hydrothermal process followed by an environmentally friendly phosphidation process. The physicochemical characterization of the CoP@OMC composite indicated that the porous CoP nanoflakes made up of bundles of ultrathin nanosheets with an approximate thickness of 30 nm are anchored on rod-like hexagonal OMC with a diameter of 110–140 nm, allowing remarkable enhancement of mesoporosity and active surface area. The CoP@OMC composite was employed as a new material for modification of electrode surface used in supercapacitor and hydrogen evolution reaction (HER). Interestingly, CoP@OMC acquired a specific capacitance of 3182 Fg−1 at current density of 1 A g−1, in 6 M KOH. Asymmetrical CoP@OMC//CB cell showed a capacity of 194 Fg−1 at the current density of 1 A g−1 with a maximum energy density of 77.9 Wh kg−1 and a power density of 17 kW kg−1. CoP@OMC composite also showed an excellent HER performance with only 111 mV overpotential to drive a current density of 10 mA cm−2 and a low Tafel slope of 43.8 mV dec−1 in 1 M KOH. Therefore, CoP(OMC) as an environmentally friendly material with high efficiency and significant catalytic / electronic properties is expected to be a good candidate for future energy storage & conversion systems.

Electrochemical charge storage performance of (Mn, Ni, Mo, Co, Fe)3O4 high entropy oxide nanoparticles produced via thermal plasma route

Highly complex high entropy metal oxides (HEOs) have several unique characteristics, such as more active sites and material stability that improve the electrochemical charge storage capacity. In this study, HEOs (Mn, Ni, Mo, Co, Fe)3O4 nanoparticles were synthesized using a thermal plasma route and its electrochemical energy storage performance was studied with two distinct electrolytes such as 1 M KOH and NaOH. The X-ray diffraction analysis revealed the phase pure spinel structured HEOs with crystalline size ranging from 13 to 29 nm. Scanning electron microscopy and electron dispersive X-ray spectroscopy results revealed the quasi-spherical morphology and uniform distribution of constitutional cations in the as-synthesized HEOs. The X-ray photoelectron spectroscopy results identified the oxidation states of cations in spinel HEOs. The charge/discharge studies of as-synthesized HEOs showed a specific capacitance of 215 F g-1 /26.9 mAh g-1 at a current density of 2 A g-1 in 1 M KOH electrolyte which is 156 % greater than 1 M NaOH electrolyte. Furthermore, a high capacitance retention of 91 % was achieved after completing 3000 cycles at 10 A g-1 current density which indicates that the HEOs have excellent charge/discharge reversibility. Electrochemical impedance spectroscopy revealed that the solution and charge transfer resistances of HEOs electrodes were 1.04 and 3.2 Ω, respectively. This novel synthesis strategy attempts to overcome the difficulties experienced by established methods for bulk manufacture of phase pure HEOs since thermal plasma method is a rapid and a single-step approach for the bulk production of nanomaterial.

Expeditious and single step synthesis of ceria quantum dots by microplasma discharge method for supercapacitor applications

In the present study, CeO2 quantum dots (QDs) were synthesized by microplasma discharge method out of cerium nitrate precursor suspension using argon gas as plasma medium. The highly energetic electrons in the microplasma plume generate highly reactive metastable OH radicals, which further combine with electrons to form OH− and react with the cerium ions (III) in the precursor solution to form CeO2 QDs. The radical produced during the process was recorded using optical emission spectroscopy. The structural features, oxidation states, morphology, elemental composition and surface area of the synthesized QDs were identified by XRD, Raman, XPS, FE-SEM, HR-TEM, EDS, PL and BET analysis, respectively. The results obtained revealed the formation of cubic phase CeO2 QDs, which was confirmed by XRD and Raman analysis. Agglomerated ceria QDs of spherical shape with an average size of around 5 nm were analyzed from FE-SEM and HR-TEM observations. The electrochemical performance of CeO2 QDs as electrode material was investigated through cyclic voltammetry analysis by an electrochemical workstation. The material achieved a highest specific capacitance of 388 Fg-1 at 1 Ag-1 current density. The commendable electrochemical performance of microplasma synthesized CeO2 QDs was attributed to the minuscule size, high surface area and the presence of Ce3+ ions. This study highlights the synthesis of CeO2 QDs through a single, rapid and amicable process without the use of secondary treatments and suggests the use of CeO2 as a good electrode material for electrochemical applications.

Effective assembling of nickel oxide-reduced graphene oxide heterostructures for ultrahigh capacity supercapattery

Developing new materials to facilitate sustainable and renewable energy storage is the most sought research frontier of the current era. In this regard, supercapacitors have drawn huge research attention in developing efficient electroactive materials. Herein, a nickel oxide/reduced graphene oxide (NiO-rGO) composite has been synthesized using the facile precipitation-aging-calcination and ultrasonication technique for energy storage applications. Due to the composite's enhanced surface area and the synergistic effect of redox-active NiO and highly conductive rGO, the resulting heterostructure exhibits excellent performance as a supercapattery. The electrochemical investigations show that the designed NiO-rGO heterostructure exhibits battery-type electrode features with an ultrahigh specific capacity of 850 Cg-1 at 1 Ag-1 current density with 91 % capacity retention even after 5000 charge-discharge cycles. The efficacy of this composite has also been tested in a symmetrical device assembly (NiO-rGO//NiO-rGO), which shows a very high maximum energy density (56.6 Wh.kg−1) and power density (9.65 kW kg−1) with excellent performance retention for 10000 charge/discharge cycles. Further, the experimental charge storage outcomes of the materials have also been supported by calculating the energetics of OH* adsorption using DFT. This work provides a facile approach to maximize the synergistic interactions within metal oxides-rGO-based 3D/2D heterostructures to derive improved electrochemical features. Moreover, it also offers experimental and theoretical insights into designing efficient and cost-effective materials for energy storage.

High-performance rechargeable aqueous zinc-iodine batteries via a dual strategy of microporous carbon nanotubes for cathodic iodine immobilization and modified separator

Compared with lithium-ion battery, aqueous rechargeable zinc-iodine is of interest due to their high safety and low cost. Unfortunately, the host material's low conductivity, small specific surface area, shuttling effect, and high soluble iodine species (I2, I-, and I3-) are inhibiting its wide development. In this work, a dual strategy of fixing iodine active material with nanotubular microporous carbon (MCN) and modified cotton fiber separator (MCN@CF) is employed to solve the above-mentioned problem. The Zinc-ion batteries (ZIBs) assembled with an MCN/I2 cathode and MCN@CF separator show up to 162 mA h g-1 of reversible initial capacity with 85 % capacity retention at 100 mA g-1 after 100 cycles. Moreover, besides featuring excellent long-term cyclability, MCN@CF battery delivers a Coulombic efficiency of 99 % over 2000 cycles with a current density of 1 A g-1. This study would lead to opening of a new paradigm for the development of highly reversible aqueous rechargeable ZIBs.

Advanced 3D hierarchical composite electrode materials for supercapacitors: Biomass derived carbon doped CoMoO4@NiCo2O4

Carbon-doped CoMoO4@NiCo2O4 on nickel foam (C-CoMoO4@NiCo2O4@Ni foam) electrode is prepared by two-step hydrothermal method. Phyllanthus reticulates extract is used as carbon source and reducing agent for preparation of CoMoO4@NiCo2O4. The XRD and FE-SEM analyses have confirmed the formation of phases and the hierarchical structure of this electrode. Moreover, this C-CoMoO4@NiCo2O4@Ni foam electrode has been directly employed in supercapacitor applications. Impressively, it exhibits a high specific capacitance of 3130 F g−1 at a current density of 1 A g−1, surpassing the performance of both C-CoMoO4@Ni foam (2482 F g−1) and C-NiCo2O4@Ni foam electrodes (1884 F g−1). Remarkably, the C-CoMoO4@NiCo2O4@Ni foam electrode maintains good rate performance, with a 60 % capacity retention after 10,000 cycles at a current density of 100 A g−1. This outstanding performance can be attributed to the distorted array of CoMoO4 nanosheets and NiCo2O4 nanoflakes, which significantly enhance the exposure of active sites and provide a larger surface area for redox reactions. In summary, the C-CoMoO4@NiCo2O4@Ni foam electrode offers exceptional specific capacity, long-term cycling stability, and excellent rate performance, making it a promising choice for various energy storage applications, including supercapacitors.

Iron oxide induced preparation of nanoscrolls of reduced graphene oxide for electrochemical charge storage applications

Fe3O4 - reduced graphene oxide nanoscrolls (FRGNS) are tailored for fabricating electrode material for supercapacitor applications. The scrolling of reduced graphene oxide is initiated by the magnetic field produced by the superparamagnetic iron oxide NPs. The formation mechanism and critical concentration of nanoparticles required for scroll formation is investigated by varying the weight ratio of iron oxide NPs. The nanoscroll formation is completely reversible and reproducible. The unique end open morphology of nanoscrolls facilitates the electrolytic accessibility and the Fe3O4 NPs favor the redox reactions as well. At a current density of 1Ag-1, FRGNS12 (rGO: Fe3O4 1:12) achieve a noteworthy specific capacitance value of 1498 Fg-1 within a potential ranging from 0 to −0.73 V in 1 M Na2S2O3 with exceptional energy density of 110.9 Wh Kg−1 and power density of 405 Wkg-1. A prominent cycling stability of 88% capacitance retention after 4000 cycles is also obtained. The electrochemical performance of opened as well as regenerated scrolls (RFRGNS12) are also evaluated. The specific capacitance increases to 1514 Fg-1 for RFRGNS12 due to the further exfoliation of rGO sheets take place during the unscrolling and scroll regeneration process. The unique fabrication methodology for the synthesis of graphene nanoscrolls and their utilization as electrode material for supercapacitors paves a new pathway for the advancement of novel electrode materials for supercapacitors.

Hybrids of porous NiMoO4@Reduced graphene oxide composites for asymmetric supercapacitor applications

A major factor in improving the specific capacitance of supercapacitors is the shape of NiMoO4. In general, it is important to have a morphology with a large surface area and thin electrolytic dielectric characteristic. In this study, a hydrothermal technique was used to create a reduced graphene oxide/nickel molybdate (NiMoO4/rGO) nanocomposite, which was then heated to 450 °C for annealing. Analyses using X-ray diffraction, Raman, and X-ray photoelectron spectroscopy proved that the NiMoO4/rGO nanocomposite was formed. A study using field emission scanning electron microscopy revealed that the rGO surface was embellished with rod-like NiMoO4 nanostructures that ranged in length from 1 to 5 m. The NiMoO4/rGO electrode, when used in the aqueous basic electrolyte, demonstrated remarkable electrochemical properties by obtaining a high capacity of 1516 Fg-1 at current densities of 1 Ag-1 with high degree of rate capability. More intriguingly, during the charge-discharge process, the NiMoO4/rGO electrode showed outstanding cycling stability of 95.8% after 10,000 cycles. In order to create a supercapattery with a large operating potential window of 1.8 V, NiMoO4/rGO is used as a positive electrode and activated carbon (AC) as a negative electrode. at 1 Ag-1 current density, an energy density of 48.2 Whkg-1 and a power density of 878 Wkg-1 were attained, showing tremendous promise for this material's use in supercapacitors.

Synthesis and characterization of cotton candy-PANI: Enhanced supercapacitance properties

Polyaniline (PANI) is a popular material for making supercapacitor electrodes due to its long-term cycle stability, specific capacitance, conductivity, mechanical robustness, scalability, and viability. All of these characteristics may be improved by introducing new architecture and employing alternative synthetic methods. The current study covers the synthesis and electrochemical performance of the protonated emeraldine salt of a newly architected PANI, which is referred in this article as cotton candy polyaniline (cc-PANI). It was found that the direct current (DC) conductivity and specific capacitance of PANI and cc-PANI electrodes are 1.21 × 10−4 Scm−1, 3.73 × 10−4 Scm−1 and 161.66 Fg-1, 203.33 Fg-1 at a current density of 1Ag-1 in a 1 M H2SO4 electrolyte solution respectively. Further, the static contact angle (CA) was found to be 38.3o and 32.6o for PANI and cc-PANI. Here, a novel designed cc-PANI was effectively synthesised and characterised. This strategy offers new hopes in the realm of PANI with improved supercapacitance qualities.

Direct interfacial growth of Sr–CeO2 nanoparticles on carbon nanofibers and their multidisciplinary applications

Cerium oxide (CeO2) and carbon nanofibers (CNF) based material have been widely used for supercapcitor, optoelectronic as well and electrochemical sensor applications due to their interesting physicochemical properties. Present article reports the facile hydrothermal synthesis of Sr–CeO2/CNF electrode material under subcritical reaction conditions. Different analytical techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–Visible spectroscopy, X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), and Transmission electron microscopy (TEM) were used for the chractrization of nanocomposite. XRD and XPS results confirm the formation of Sr–CeO2/CNF having cubic fluorite structure. In addition, morphological studies shows formation of dot like morphology of Sr–CeO2 nanoparticals embedded on CNF nanorods. Surface area analysis indicated that synthesized material is mesoporous in nature and exhibited high surface area of 38.45 m2/g. The optical absorption concludes that the band gap values lies between 2.1 and 3.15 eV, suitable for optoelectronic applications. Moreover, the electrochemical study of 5 wt% Sr–CeO2/CNF exhibits substantial specific capacitance of 192 Fg-1 with 95.4% good cyclic stability at 5000 cycles. The composite electrode exhibit energy density and power density of 96 WhKg−1and 1440 WKg−1at 0.8 Ag-1 current density suggesting a good electrode material for supercapacitor. Finally, the nanocomposite was also studied for cyclic voltammetric electrochemical detection of Harmaline (HAR) showing good sensitivity with Limit of detection (LOD) and Limit of quantification (LOQ) of 0.82 μg mL−1 and 2.48 μg mL−1 respectively.

The Co3O4–Co3(PO4)2 nanocomposite supercapacitor system: Synthesis, electrochemistry, temperature effects, and computational studies

Supercapacitors with improved storage capacity and longer operational times are in high demand. Herein we report the charge storage nanocomposite cobalt(II, III) oxide/cobalt(II) phosphate, Co3O4–Co3(PO4)2, formed in the calcination temperature range 600–800 °C showing varying degrees of crystallinity. The isolated Co3O4–Co3(PO4)2 nanocomposite was characterized by Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, powder X-ray diffraction and high-resolution Transmission Electron Microscopy (HRTEM) and Scanning Electron Microscopy (SEM). Cyclic voltammetry studies based on a three-electrode system showed that Co3O4–Co3(PO4)2 formed at 700 °C exhibited the highest specific capacitance behaviour of 538.3 Fg-1 at 0.5 mVs−1 in 3 M KOH electrolyte. Galvanostatic charging and discharging studies showed a specific capacitance of 526.9 Fg-1 at 1 Ag-1 current density. The unrestricted Becke-3-Lee-Yang-Parr (UB3LYP) functional in conjunction with the 6–311g(d,p) basis set was used for quantum calculations of the thermo-chemical properties of the Co3(PO4)2 moiety in the nanocomposite. The entropy and heat capacity showed optimum temperature values for the nanocomposites in the order 600 °C > 800 °C > 700 °C, the most suited electrode material for charge storage was found at 700 °C. The electronic measurement for the cobalt(II) phosphate moiety in the nanocomposites indicated that the system was very polar with a low bandgap and good electronic and ionic conductivity.

Exploration on magnetic and electrochemical properties of nitrogen and phosphorus Co-doped ordered mesoporous carbon for supercapacitor applications

A series of heteroatom doped ordered mesoporous carbons (HOMCs) such as ordered mesoporous carbon (OMC), nitrogen doped ordered mesoporous carbons (NOMC), phosphorus doped ordered mesoporous carbons (POMCs), and nitrogen and phosphorus co-doped ordered mesoporous carbon (NPOMC) were synthesized via a chemical vapor deposition nanocasting (CVD nanocasting) route using SBA-15 as the template at 800 °C for high-performance supercapacitor. The formation of the template and HOMCs were confirmed by various physicochemical characterization techniques such as XRD, RAMAN, BET, SEM-EDAX, HR-TEM and XPS. The magnetic properties of prepared HOMCs were measured. Also, the electrochemical properties of HOMCs were evaluated using electrochemical analyses such as CV, EIS and GCD in 1 M H2SO4 medium. Among the various prepared HOMCs, sample NPOMC showed a high specific capacitance of 355 Fg-1 at a current density of 0.5 Ag-1 due to the heteroatoms. Moreover, the symmetric device fabricated using NPOMC exhibited 98% columbic efficiency with 98% capacitance retention after 1000 cycles at 2 Ag-1 current density.

Designing High-Performance Symmetric Supercapacitors from Waste Jute and Bio-Electrolyte

The performance of porous carbon (PC)-based supercapacitor especially the energy density for the most part is dependent on its electrolytic system. Sodium sulfate (Na2SO4) is the most studied neutral aqueous electrolyte system studied so far for the PC-based electric double-layer capacitors (EDLC). But the theoretical value for the working potential of Na2SO4 is limited to only 1.23 V, and hence it limits the energy density of the storage system. Here, we are reporting the fabrication of a supercapacitor electrode derived from waste jute using the bio- electrolyte sodium acetate (SA) as an alternative to the Na2SO4 electrolyte. Due to its unique physicochemical properties, the 0.5 M SA electrolyte could successively be able to expand (0.5 V) the working potential of the fabricated supercapacitor. Thus, the system achieved almost four times higher energy density when using SA electrolyte instead of Na2SO4. The SA electrolyte-based EDLC showed an outstanding specific capacitance of 213 Fg-1 at 1 Ag-1 current density were retaining 92% capacitance even after 10,000 cycles.

A Facile Synthesis of High Performing MnxOy-Rgo Hybrid Composite for Potential Supercapacitor Application

In this study, the facile synthesis procedure of MnxOy-rGO hybrid and the variation of its electrochemical performance on varying the KMnO4 concentration have been elucidated. The as prepared hybrid was synthesized by adopting a one-step hydrothermal process at 180°C for 24h. The controlled growth of mixed manganese oxide (MnxOy) was achieved for 0.5 mM KMnO4, and it showed a specific capacitance of 280 Fg-1 at 1 Ag-1 current density using 0.5 M Na2SO4 electrolyte. The incorporation of the MnxOy into the conductive rGO layers successfully prevented the self-agglomeration of rGO nanosheets. It was found that an appropriate incorporation of MnxOy provided the fast electrolytic ion transportation in and on between the rGO layers by reducing the solution resistance, (Rs) down to 4 ohm (Ω). Hence, it is expected that the synthesis procedure for the fabrication of MnxOy-rGO has prospects as the high performing supercapacitor electrode materials.

Redox Mediated Neutral Electrolyte Solution for High Performing Ni(OH)2-MnO2-Rgo Supercapacitor Electrode

Using a redox-mediated neutral electrolytic system (0.5 M Na2SO4+ 0.5 M K4FeCN6), a ternary hybrid of Ni(OH)2-MnO2-rGO as a supercapacitor electrode was investigated. The hybrid electrode was synthesized by adopting a simple hydrothermal approach. The phase of the α-Ni(OH)2 and γ-MnO2 was confirmed by X-ray Diffraction (XRD), as well their incorporation was observed by High-resolution transmission electron microscopy (HRTEM). The hybrid electrode in the redox system has demonstrated appealing performance due to the improved charge transfer capability of redox-active K4FeCN6, and hence, a high specific capacitance of 870 Fg-1 was found within the potential window of 0-1.0 V at 1 Ag-1 current density. As well, a high energy density of 30.2 Whkg-1 was found by using a symmetrical two-electrode setup. On top even after 5000 cycles, this supercapacitor has shown 92% of capacitance retention while maintaining 95% Coulombic efficiency. From a comparative perspective, the electrode was also tested on neutral Na2SO4, KOH, and H2SO4 electrolytes.