The development of Lithium batteries has gained more attention nowadays. polyethylene oxide (PEO)/Polyvinyl pyrrolidone (PVP) based Solid polymer electrolytes (SPEs) was prepared with lithium bromide ...by solution casting technique. From the X-ray diffraction studies, the amorphous nature of the polymer blend with the inclusion of LiBr had been studied. FT-IR study was used to find the presence of functional groups and the complex formation between the bonding of polymers. The maximum ionic conductivity was found to be 1.59 × 10−6 S/cm for PEO (30 wt %)/PVP (70 wt %)/Lithium bromide (4 wt %) at 303 K within the frequency range of 42 Hz - 1 MHz. The dielectric response of the SPE systems was studied at the temperature range of 303–363 K. An important factor of ion conduction is the relaxation behavior of polymer chains which was clarified by the dielectric properties of the SPE systems. Further, the capability of the polymer to dissolve salt was determined by the dielectric constant (ε). At lower frequencies, the higher dielectric permittivity was attained due to deposit of ionic charges. The ionic movement enhances the dielectric loss and dielectric permittivity. The conductivity relaxation process and the ion hopping mechanism have been explained by using the Electric modulus analysis.
•PEO/PVP based solid polymer electrolytes (SPEs) was prepared with lithium bromide by solution casting technique.•X-ray diffraction studies confirmed the amorphous nature of polymer blend with the inclusion of LiBr.•FT-IR study confirmed the functional groups and the complex formation between the bonding of polymers.•The ionic movement enhances the dielectric loss and dielectric permittivity.•The conductivity relaxation process and the ion hopping mechanism have been explained by using the Electric modulus analysis.
The cobalt sulfide (Co9S8) nanoparticles (NPs) have been synthesized by the solvothermal techniques by utilizing Cobalt diethyldithiocarbamate (CoDTC2) as single-source precursor and hexadecylamine ...(HDA) as shape directing agent. As-prepared Co9S8 NPs were characterized with structural, morphological, thermal, Spectroscopic and surface analysis using PXRD, TEM, SEM-EDS, TG/DTA, FTIR, Raman and XPS studies respectively. The electrochemical performances were investigated by galvanostatic charge-discharge (GCD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) analysis with Co9S8 NPs modified working electrode. The Co9S8 NPs modified electrode delivered excellent specific capacitances of 502 Fg-1 at current densities of 1 Ag-1. The capacitance retention of Co9S8 was found to be 87% over the examination even after 7000 cycles. Furthermore, a hybrid supercapacitor (HSC) device assembled with cathode and anode materials delivers a high energy density of 15.47Whkg-1 with power density of 1274.9Wkg-1.
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•Co9S8 nanoparticles have been successfully synthesized by simple solvothermal reflex method.•PXRD and SEM exhibit the cubic crystalline structure and spherical-like morphology for Co9S8 nanoparticles.•Co9S8 electrode material exhibits Faradic pseudo capacitive behaviour.•An enhanced high specific capacitance of 502 Fg-1 and current density of 1 Ag-1.•The Co9S8 electrode material exhibits 87% energy retention in cyclic test after 7000 cycles.
Mixed transition-metal oxides are emerging electrode materials, because of their higher electrochemical performances. In the present work, single-metal oxides, binary-metal oxides, and ternary ...mixed-metal oxides (MMOs) of zinc oxide (ZnO), nickel oxide (NiO), and copper oxide (CuO) are successfully prepared by simple gel-combustion process. The structure and properties of MMOs are of great interest, because of the opportunity to tune their properties for better multifunctional performance than single and binary metal oxides. The crystal structure, functional group, surface morphology, and binding energy of all of the single, binary, and ternary MMOs are studied through X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron microscopy (XPS), respectively. The entire electrochemical studies are also performed using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). From the electrochemical study, the ZnO–NiO–CuO MMOs electrode was found to possess pseudocapacitor-type features and shows an outstanding specific capacitance of 1831 F g–1 at a current density of 1 A g–1, which is higher than that of single and binary metal oxides. The fabricated asymmetric (ASC) device ZnO–NiO–CuO MMOs || r-GO exhibits maximum specific capacitance of 118 F g–1 at the current density of 1 A g–1. Hence, it leads to the supercapacitance property of maximum storage response; the ASC device possessed the excellent retentivity of (89.97%) up to 10 000 repeated cycles. The ASC device reveals a maximum specific power of 5672 W h kg–1 with a specific energy of 15.7 W h kg–1 with a high current density of 10 A g–1. This finding shows that the ZnO–NiO–CuO MMOs can be used as potential electrode material and might have promising applications in high-performance energy storage devices.
Lithium ion conducting solid polymer blend electrolytes (SPBE) are prepared using the host polymers polyvinylalcohol (PVA), polyvinyl pyrrolidone (PVP) and the lithium acetate. The complexation ...between the polymers and salt is confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The glass transition temperature of the prepared polymer electrolytes is determined by differential scanning calorimeter. Surface morphology of the polymer electrolytes is identified by scanning electron microscopy. Ionic conductivity of the solid electrolytes is studied using impedance analyzer in the frequency range of 42 Hz–1 MHz. The higher electrical conductivity of 5.79 × 10
−6
S cm
−1
and 1.400 × 10
−4
S cm
−1
is determined for 50PVA:50PVP:25 wt% lithium acetate system at 303 K and 363 K temperature, respectively. The dielectric and loss tangent analysis is also carried out for prepared polymer electrolyte and the higher-conductivity sample at different temperatures. The transference numbers of polymer electrolytes are calculated by Wagner’s polarizing technique and also confirmed by Bruce–Vincent technique.
•The reported work demonstrates the synthesis of pristine WO3 and Manganese (Mn)-doped WO3 through co-precipitation method.•A dynamic increment in AC conductivity was observed with doping even at ...room temperature.•We prove that Mn-doped WO3 nanoparticles are an outstanding candidate for applications for supercapacitors.•The electrochemical properties of Pure and Mn-doped WO3 samples were analysed through cyclic voltammetry measurements.•1 wt% Mn-doped WO3 electrode reports excellent electrochemical efficiency.•An electrochemical efficiency of (1178 F/g specific capacitance at 2 mA/cm2 ) is reported for 1 wt% Mn-doped WO3 supercapacitors.•1 wt% Mn- doped electrode material also delivers a long cycle life (94.2% capacity over 5,000 repetitive GCD cycles).
The work reported here, demonstrates the synthesis of pristine WO3 and Manganese (Mn)-doped through the hydraulic acid-assisted precipitation method. Structural, morphological, compositional, optical and electrochemical properties of the synthesized samples were analysed. The structural analysis through X-ray diffraction studies confirmed the monoclinic phase of WO3 as well as the substitutional incorporation of Mn inWO3 lattice. A bandgap value of 2.9 eV was estimated from Optical analysis using Kubelka-Munk model. The defect centered luminescence as a consequences of Mn doping was analyzed using photoluminescence spectroscopy (PL). FT Raman Spectroscopic data also reconfirmed the monoclinic structure of the sample and incorporation of Mn into the lattice of Mn-doped WO3. The surface morphological study was performed using Field Emission Scanning Electron Microscope (FESEM), which exhibits the development of mesoporous networks. The Conductivity, dielectric and electrochemical studies were performed on these mesoporous structures to inveterate the impact of Mn doping. A dynamic increment in AC conductivity was observed with doping even at room temperature. Most significantly, we prove that Mn doped WO3 for the first time, Nanoparticles are an outstanding candidate for applications for supercapacitors. Pure and Mn doped WO3 electrochemical properties cyclic voltammetry measurements have been used to analyze samples. The results showed the excellent electrochemical efficiency on 1 wt% Mn doped WO3 electrode (1178 F/g specific capacitance at 2 mA/cm2 and charge transfer ability) for supercapacitors.
Nanostructured sodium alginate (Na Alg.) assisted CuS nanoparticles are synthesized by graceful microwave irradiation method. The prepared CuS nanofiller is mixed by means of magnesium ion conducting ...PVA:PVP blend electrolyte films with different compositions using solution casting method. All compositions are characterized to analyse its structural and thermal properties through X-ray Diffraction (XRD), Fourier Transform infrared (FTIR) and Thermo gravimetric and Differential Thermal analysis (TG/DTA) techniques. The electrical conductivity and dielectric properties are analyzed through electrical impedance measurements. Nanofillers mixed Mg:PVA:PVP blend polymer solid electrolyte exhibit maximum protonic conductivity of 1.847 × 10−3 Scm−1. Proton and magnesium ion based conducting solid electrolytes are more applicable for energy storage devices applications.
•Na Alg. assisted CuS synthesized by microwave irradiation method and CuS nanofillered PVA:PVP:MgCl2 polymer films by solution casting method.•All composition of nanofiller mixed Mg:PVA-PVP blend polymer solid electrolyte are examined.•Electrical conductivity and dielectric properties are analyzed through electrical impedance measurements.•Nanofillers mixed Mg:PVA-PVP blend polymer solid electrolyte exhibit maximum protonic conductivity.•Mg:PVA-PVP based conducting electrolytes are more applicable for energy storage devices applications.
ZnO nanorods embedded on functionalized CNT have been synthesised by the chemical refluxing method. The characterization results revealed the tube-like structure of carbon nanotubes, that expose the ...ZnO nanorods grafted upright and parallel on the floor across the CNT surface. The powder X-ray diffraction patterns show that crystalline ZnO nanorods are highly loaded on the surface of CNT and formed as a nano-composite. Raman spectroscopy results showed that the intensity of D and G bands decreased due to the loading of ZnO nanorods. Cyclic voltammetry curves reveal the double layer capacitor (EDLC) behaviour of ZnO/CNT. The synthesised hybrid ZnO/CNT exhibits a high specific capacitance (SPc) of 189 Fg-1. The quick charge-discharge performance was found about 95 Fg-1 and the cyclic stability of 96% was observed for 1000 cycles. ZnO/CNT nano-composites also exhibit a high power density of 2250 W kg-1.
•Uniform shape and size ZnO nanorod decorated on functionalized CNT was synthesised.•Electrochemical behaviour of ZnO/CNT was studied (CV, GCD and ESI) in Na2SO4 electrolyte.•EDLC specific capacitance was found to be 189 F/g at 1 mVs−1.•High power density of 2250 W/Kg with energy density of 10.7 Wh/Kg was found.•Cyclic life with retention of capacitance was found about 96% after 1000 cycles.
Lanthanum (Rare earth metal) doped CuS (La@CuS) at different compositions (0%, 1%, 3% and 5% of La) are synthesized by encapsulation of sodium alginate biopolymer using microwave irradiation method. ...The prepared various compositions of La@CuS are examined by structural characterizations, particle size and identifications of elements from XRD, TEM and EDX spectrum. The surface morphological studies are conformed by SEM and TEM images. Optical properties and characteristics peak are confirmed with UV, FTIR and Raman spectroscopic tools. In addition to that the electrochemical performances are studied using Cyclic Voltammetry (CV), Galvanostatic charge and discharge (GCD) and electrochemical impedance spectroscopy (EIS) investigations. The specific capacitance is found to be 1329 F/g for 5% of La doped CuS nano spheres.
•Biopolymer encapsulated CuS and La doped CuS NPs synthesized by chemical reflux method.•La doped CuS NPs were analysed by XRD, FTIR, SEM, TEM and EDX techniques.•La doped CuS NPs were investigated electrochemical studies (CV, GCD and ESI) with 1 M of KOH aqueous electrolyte solution.•Cyclic life of 91% retention of capacitance after 1000 cycles was found.
Solid polymer electrolytes (SPEs) consisting of polyethylene oxide (PEO) /Polyvinyl pyrrolidone (PVP) complexed with sodium nitrate have been synthesized by solution casting technique. Structural ...studies were carried out using X-ray diffraction (XRD) measurements. The complex formation between the bonding of polymers and the salt were confirmed by Fourier Transform Infrared (FT-IR) spectral data. The ionic conductivity and dielectric response of the SPEs were studied within the frequency range of 42 Hz–1 MHz at the temperature range of 303–363 K. The maximum ionic conductivity was found to be 6.157 × 10−7 S/cm at 303 K for PEO (67 wt %) /PVP (27 wt %)/NaNO3 (6 wt%). The dielectric properties were also studied using the complex dielectric permittivity spectra of the SPE films. The higher dielectric permittivity was obtained due to accretion of ionic charges at lower frequencies. The surface morphology of the polymer blend electrolyte film complexed with sodium nitrate was studied using Scanning Electron Microscopy (SEM).
•Blend Polymer electrolytes are easily prepared by solution casting technique.•XRD Confirmed the reduction of amorphous nature in nitrate salt mixed PEO-PVP blend polymer matrices.•FTIR characterize the structural identification of the polymer matrix through the existing functional group.•The highest bulk conductivity is observed as 6.157 × 10−7 S/cm for 6 wt% sodium nitrate blend PEO/PVP polymer matrix.•Ionic transport number is found to be ∼95% for all prepared polymers.
Solid polymer electrolytes used in energy storage devices based on Cornstarch and Poly (vinyl Pyrrolidone) blend incorporated with lithium acetate was prepared using the solution casting method. XRD ...results confirmed that the amorphous nature of the as-prepared polymer electrolyte was increased by addition of salt. 80 wt % Cornstarch/20 wt % PVP/60 wt % lithium acetate added polymer blend system attains better amorphous nature than others. At ambient temperature, 60 wt % of lithium acetate added system has better bulk conductivity of 3.52 × 10−5Scm−1 over the frequency range of 42 Hz to 1 MHz using AC impedance spectroscopy studies. The dielectric analysis is confirmed that the higher conducting sample was having high dielectric constant and low relaxation time for enhancing ions dynamic behaviour. The conduction mechanism of the higher conducting polymer electrolyte is explained by small polaron hopping and overlapping large polaron tunnelling conduction mechanism. From the argand plot, it is confirmed that higher conducting sample has low relaxation time.
