Nanocomposite Polymer Electrolyte System Research Articles

New Network Polymer Electrolytes Based on Ionic Liquid and SiO2 Nanoparticles for Energy Storage Systems.

Elementary processes of electro mass transfer in the nanocomposite polymer electrolyte system by pulse field gradient, spin echo NMR spectroscopy and the high-resolution NMR method together with electrochemical impedance spectroscopy are examined. The new nanocomposite polymer gel electrolytes consisted of polyethylene glycol diacrylate (PEGDA), salt LiBF4 and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) and SiO2 nanoparticles. Kinetics of the PEGDA matrix formation was studied by isothermal calorimetry. The flexible polymer-ionic liquid films were studied by IRFT spectroscopy, differential scanning calorimetry and temperature gravimetric analysis. The total conductivity in these systems was about 10-4 S cm-1 (-40 °C), 10-3 S cm-1 (25 °C) and 10-2 S cm-1 (100 °C). The method of quantum-chemical modeling of the interaction of SiO2 nanoparticles with ions showed the advantage of the mixed adsorption process, in which a negatively charged surface layer is formed from Li+ BF4- ions on silicon dioxide particles and then from ions of the ionic liquid EMI+ BF4-. These electrolytes are promising for use both in lithium power sources and in supercapacitors. The paper shows preliminary tests of a lithium cell with an organic electrode based on a pentaazapentacene derivative for 110 charge-discharge cycles.

Nanocomposite polymer electrolytes comprising starch-lithium acetate and titania for all-solid-state supercapacitor

A nanocomposite solid polymer electrolyte (SPE) system has been prepared for application in a supercapacitor. Corn starch is used to host the ionic conduction with lithium acetate (LiOAc) salt as an ion provider. Different concentrations of nanosized titanium dioxide (TiO2) filler have been added to analyse the influence of nanofiller addition on the conductivity and other properties of the electrolytes. Structural characterisation and complex formation have been examined by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy, respectively. It is shown that the room temperature conductivity changes with the change in TiO2 concentration. Adding 4 wt.% TiO2 to the starch-LiOAc complex leads to an optimum conductivity of (8.37 ± 1.04) × 10−4 S cm−1. The variation in conductivity is accompanied by the change in surface morphology as observed from field emission scanning electron microscopy (FESEM) analysis. Linear sweep voltammetry (LSV) indicates that the electrochemical potential stability window of the electrolyte with 4 wt.% TiO2 lies in the range between − 2.0 and + 1.9 V. A supercapacitor has been assembled using the electrolyte, and its performance has been characterised using impedance technique and cyclic voltammetry.

Enhancement of Ionic Conductivity and Dielectric Permittivity for PMMA-Based Polymer Electrolyte with BaTiO3NanoFiller

The design of the lithium polymer battery with excellent performance needs proper exploration of the materials. Poly(methyl methacrylate) (PMMA)-hosted solid nanocomposite polymer electrolyte systems are prepared by solvent-casting technique. A fixed amount of propylene carbonate (PC) is used as a plasticizer, barium titanate (BaTiO[Formula: see text] as a nanofiller and lithium hexafluorophosphate (LiPF[Formula: see text] as a dopant salt. The characterization of nanocomposite solid polymer electrolyte (SPE) was carried out using scanning electron microscope (SEM), and the outcome revealed the formation of a three-dimensional network with dispersed nanofillers. The dielectric constants and ionic conductivities for different wt.% of nanofiller with different temperature ranges are measured by impedance analyzer. It is observed that for 15[Formula: see text]wt.% of nanofiller-mixed electrolyte sample, a highest dielectric constant of 5166 and a maximum ionic conductivity of [Formula: see text] S[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] are achieved.

Role of Multiferroic Filler on the AC Response of Bi1‐xBaxFeO3 doped PVA:NH4CH3COO Nanocomposite Gel Polymer Electrolytes

AbstractThe frequency dependent AC conductivity and dielectric studies of multiferroic filler (Bi1‐xBaxFeO3) doped nanocomposite gel polymer electrolyte (NCGPEs) based on PVA:(NH4CH3COO) are investigated in the present work. The nano composite gel polymer electrolyte systems are synthesized for various filler concentrations by solution cast method. The effect of filler concentration on ionic conductivity is studied using AC impedance technique in the frequency range 1–106 Hz. X‐ray diffraction studies reveal the formation of nanocomposite gel polymer electrolyte. The low frequency dispersion in the dielectric response of electrolytes shows the relaxation contribution is superimposed with electrode polarization effects. The relaxation peaks in the NCGPEs are found to shift toward higher frequency side with increasing filler concentration and are suitably correlated to change in morphology of the gel electrolyte system. The variation of AC conductivity with frequency is seen to obey Jonscher's universal power law with the exception of small deviation in the low frequency regime. Modulus formalism of dielectric response suggests that the ion transport is strongly coupled to the polymer segmental motion.

Effect of Al2O3 nanoparticles on ionic conductivity of PVdF-HFP/PMMA blend-based Na+-ion conducting nanocomposite gel polymer electrolyte

In the present work, the effect of dispersion of Al2O3 nanoparticles on ionic conductivity of non-aqueous PVdF-HFP/PMMA blend-based nanocomposite gel polymer electrolyte system comprising liquid electrolyte of sodium trifluoromethanesulfonate is investigated. The ionic conductivity of the electrolyte increases maximum to ∼ 1.5 × 10−3 S cm−1 for the composition with 6 wt% Al2O3 nanoparticles. The optimized composition retains Vogel-Tamman-Fulcher (VTF) behavior in the temperature range from − 50 to 95 °C. The scanning electron micrography and x-ray diffraction studies reveal the uniform dispersion of Al2O3 nanoparticles in the porous structure of the nanocomposite gel polymer electrolyte and enhanced amorphicity of polymer matrix. The optimized electrolyte composition owns a sufficiently large electrochemical stability window of ~ 3.6 V with good sodium ion transference number. The optimized electrolyte is used in a prototype sodium battery cell, which shows an open circuit potential of ~ 2.5 V and first discharge capacity ~ 400 mA h g−1 followed by a capacity decline with cycling.

Gamma irradiation effects on conductivity and dielectric behaviour of PEO-based nano-composite polymer electrolyte systems

The effect of gamma irradiation on physical and electrical properties of polyethylene oxide (PEO)-based nano-composite polymer electrolyte films was investigated. The structural change induced and the reduction in crystallinity of the electrolyte film before and after irradiation were confirmed by FTIR spectra and X-ray diffraction studies. Microstructural studies carried out by scanning electron microscope technique reveal significant change in the surface morphology on irradiation. The bulk conductivities of the films were studied using standard impedance spectroscopic technique. A maximum ionic conductivity of 1.717 × 10−4 S cm−1 was observed for 40 kGy radiation dose, which is higher than earlier reported studies. Ion dynamics behaviour of the films was studied by frequency-dependent conductivity measurements which follow universal power law. The dielectric constant tends to be higher for films with higher lithium ion conductivity.

Spectroscopic and Discharge Studies on Graphene Oxide Doped PVA/PVP Blend Nanocomposite Polymer Films

Graphene oxide (GO) nanoparticles were synthesized by modified Hummers method. The synthesized GO nanoparticles were incorporated in polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) blend polymers for the preparation of nanocomposite polymer films by solution cast technique. Different characterizations such as XRD, UV–Vis and FTIR were carried-out on to the prepared nanocomposite polymer films. The thermal analysis of the films was studied by DSC. The morphology of PVA/PVP:GO polymer films confirms GO was exfoliated within the PVA/PVP matrix and also reveals the heterogeneous phase of nanocomposite polymer electrolyte systems. From the conductivity studies the highest conductivity of PVA/PVP: GO (0.45: 0.3) was found to be 8.05 × 10–4 S/cm at room temperature. Solid state battery has been fabricated with the configuration of Mg+/(PVA/PVP:GO)/(I2 + C + electrolyte) and its cell parameters were calculated for a constant load of 100 kΩ.

Optical and dielectric properties of PVP based composite polymer electrolyte films

Solid polymer electrolyte films were prepared by adding Al2O3 particles to poly(vinylpyrrolidone)-MgCl2 ∙ 6H2O salt using solution cast technique. Various analytical techniques have been applied to characterize the prepared polymer films such as XRD, SEM, UV–Vis spectroscopy and AC conductivity. The structural analysis of pure poly(vinylpyrrolidone) complexed with MgCl2 ∙ 6H2O salt showed orthorhombic lattice structure indicating its semi-crystalline nature. SEM analysis reveals the heterogeneous phase of nanocomposite polymer electrolyte systems. The conductivity of Al2O3 doped poly(vinylpyrrolidone) based solid polymer electrolyte was found to be 1.22 × 10–6 S/cm at room temperature for 85: 15 weight composition. Electrochemical cell has been fabricated with the configuration Mg+/(PVP + MgCl2 ∙ 6H2O + Al2O3)/(I2 + C + electrolyte) and its discharge characteristics were studied for a constant load of 100 kΩ. Various cell parameters such as open-circuit voltage, short circuit current, energy density and power density were calculated for the prepared samples.

Effect of Al2O3 nanofiller on the electrical, thermal and structural properties of PEO:PPG based nanocomposite polymer electrolyte

A new series of nanocomposite polymer electrolyte (NCPE) system comprising of polyethylene oxide (PEO) and polypropylene glycol (PPG) as blended polymer host, zinc trifluoromethanesulfonate [Zn(CF3SO3)2] as dopant salt and nanocrystalline alumina [Al2O3] as filler was prepared by solution casting technique. The present system consisting of five different compositions of 87.5 wt% (PEO:PPG)–12.5 wt% Zn(CF3SO3)2 + x wt% Al2O3 [where x = 1, 3, 5, 7 and 9, respectively] has been thoroughly characterized by various analytical techniques such as electrical impedance spectroscopy, X-ray diffraction (XRD) studies, differential scanning calorimetry (DSC), scanning electron microscopic (SEM) analysis and linear sweep voltammetry (LSV). The maximum room temperature ionic conductivity exhibited by the NCPE was found to be 2.1 × 10−4 S cm−1 for 3 wt% loading of Al2O3 which is an order higher than that of the optimized filler-free zinc salt doped polymer electrolyte system at 298 K. The evidence of a decrease in the degree of crystallinity responsible for the enhanced conductivity was revealed by the XRD data and further confirmed by DSC and SEM results. Moreover, the electrochemical stability window of the highly conducting electrolyte matrix has been experimentally determined by linear sweep voltammetry and found to be 3.6 V which is fairly adequate for the construction of zinc primary batteries as well as zinc-based rechargeable batteries at ambient conditions.

Influence of Nano-Filler Concentration on Transport Properties of PVA-PEO Blend Systems

In the present study, two different PVA-PEO nanocomposite blend polymer electrolyte systems viz., System-I: [(PVA)(42.5):(PEO)(42.5):(AgNO3)(5):(PEG)(10):(Al2O3)(x)] and System-II: [(PVA)(47):(PEO)(47):(LiCF3SO3)(9):(EC)(6):(Al2O3)(x)] are prepared using solution cast technique for various Al2O3 nanofiller amounts ranging from 2 to 10 wt%. The influence of Al2O3 concentration on the transport properties of the electrolytes of both these systems is closely inspected. Here, the ionic transport number (ti) measurements of the blend specimens are carried out using ‘dc Polarization Technique’.

Impedance and dielectric studies of nanocomposite polymer electrolyte systems using MMT and ferroelectric fillers

Impedance and dielectric properties of nanocomposite polymer electrolyte systems modified with nano size MMT and ferroelectric fillers have been investigated for varying lithium to oxygen ratios. The changes in the structural properties of the electrolyte samples were characterized by X-ray diffraction (XRD) and differential scanning calorimetric (DSC) technique. The ion transport number estimated by DC polarization technique is found to be between 0.86 and 0.95. The bulk conductivities of nanocomposite polymer electrolyte films were studied using impedance spectroscopic technique. The impedance plot shows high frequency semicircle, due to the bulk effect of sample and maximum ionic conductivity of 2.15 × 10−4 Scm−1 was observed for (PEO)4LiCBSM at 323 K with lithium to oxygen ratio 1: 4. The complex impedance data was used to evaluate ionic conductivity and dielectric relaxation process, to understand the ion transport mechanism in these systems.

Mathematical modeling of field-assisted Li ion conduction in nanocomposite solid polymer electrolyte systems

Nanocomposite solid polymer electrolyte films were prepared to study the effect of electric field on the ionic conductivity. The studies were carried out by varying the electric field from 0 to 100 V cm−1 at different temperatures and the results shows that conductivity increases with increase in electric field and temperature. A mathematical model is proposed to describe the electric field and temperature-dependent ionic conductivity in nanocomposite solid polymer electrolyte systems. The correlation between the proposed equation and the experimental observations showed high degree of correlation.

Effect of TiO2 nanoparticles on structural, thermal, mechanical and ionic conductivity studies of PEO12–LiTDI solid polymer electrolyte

In the present study, poly(ethylene oxide) (PEO) complexed with lithium 2-trifluoromethyl-4,5-dicyanoimidazole (LiTDI) nanocomposite solid polymer electrolyte membranes (NSPEMs) have been prepared by solution cast technique using different weight percent of nano-sized TiO2 ceramic filler. The effect of filler incorporation on the structural, thermal, mechanical and ionic conductivity properties of solid polymer electrolytes have analyzed. X-ray diffraction (XRD) and polarized optical microscopy (POM) results indicated that the crystallinity has been reduced remarkably with the incorporation of TiO2 nanofiller. The thermal stability and mechanical integrity of the nanocomposite polymer electrolyte system increased significantly compared to filler free electrolytes. The maximum ionic conductivity is found to be in the range of 2.11×10−5Scm−1 for 8wt% TiO2 nanofiller in PEO12–LiTDI electrolyte system. These results indicated that the prepared TiO2 based nanocomposite membrane would be a promising alternative separator for rechargeable lithium-ion battery applications.

CeO2-TiO2 photoanode for solid state natural dye-sensitized solar cell

The main challenge facing liquid electrolyte-based dye-sensitized solar cells (DSSCs) is the leakage and valorization of organic solvents limiting the long-term durability and practical use of DSSC. Therefore, the solidification of the electrolyte used in these devices has been one of the most crucial research directions in the field of DSSC. In the present work, we have assembled a dye-sensitized solar cell based on a new nanocomposite polymer electrolyte system which is composed of polyvinyl alcohol as a host polymer, mixture of EC and PC as a plasticizer, LiI:I2 as a redox couple, and TiO2 as a filler. A novel photoanode CeO2-TiO2 sensitized with betacyanin natural dye was used in order to reduce recombination rate by providing inherent energy barrier. The obtained solar energy conversion efficiency was of 2.8 % with a current density JSC of 7.22 mA/cm2 using an irradiation of 100 mW/cm2 at 25 °C.

Nanocomposite blend gel polymer electrolyte for proton battery application

A proton-conducting nanocomposite gel polymer electrolyte (GPE) system, [35{(25 poly(methylmethacrylate) (PMMA) + 75 poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP)) + xSiO2} + 65{1 M NH4SCN in ethylene carbonate (EC) + propylene carbonate (PC)}], where x = 0, 1, 2, 4, 6, 8, 10, and 12, has been reported. The free standing films of the gel electrolyte are obtained by solution cast technique. Films exhibit an amorphous and porous structure as observed from X-ray diffractometry (XRD) and scanning electron microscopy (SEM) studies. Fourier transform infrared spectrophotometry (FTIR) studies indicate ion–filler–polymer interactions in the nanocomposite blend GPE. The room temperature ionic conductivity of the gel electrolyte has been measured with different silica concentrations. The maximum ionic conductivity at room temperature has been observed as 4.3 × 10−3 S cm−1 with 2 wt.% of SiO2 dispersion. The temperature dependence of ionic conductivity shows a typical Vogel-Tamman-Fulcher (VTF) behavior. The electrochemical potential window of the nanocomposite GPE film has been observed between −1.6 V and 1.6 V. The optimized composition of the gel electrolyte has been used to fabricate a proton battery with Zn/ZnSO4·7H2O anode and PbO2/V2O5 cathode. The open circuit voltage (OCV) of the battery has been obtained as 1.55 V. The highest energy density of the cell has been obtained as 6.11 Wh kg−1 for low current drain. The battery shows rechargeability up to 3 cycles and thereafter, its discharge capacity fades away substantially.

Effect of propylene carbonate as a plasticizer on (PEO)50AgCF3SO3:SnO2 nanocomposite polymer electrolyte

This work deals with the incorporation of propylene carbonate (PC) as a plasticizer in conjunction with poly (ethylene oxide) (PEO), silver triflate (AgCF3SO3) and nanocrystalline tin oxide (SnO2) for obtaining the nanocomposite polymer electrolyte system (PEO)50AgCF3SO3:2 wt% SnO2 + x wt% PC (x = 10, 20, 30 and 40) by solution casting method. The present electrical conductivity data extracted by means of complex impedance spectroscopic analysis in the frequency range 20 Hz–1 MHz and over the temperature domain 298–373 K have demonstrated that the maximum electrical conductivity value of 5.9 × 10−5 S cm−1 at 298 K would be possessed by the specimen containing 30 wt% PC incorporated into the optimized nanocomposite system (PEO)50AgCF3SO3:2 wt% SnO2. Silver ionic transference number (tAg+) data evaluated using AC/DC polarization technique have indicated that the highest tAg+ value of 0.52 could be realized in the case of the specimen (PEO)50AgCF3SO3:2 wt% SnO2 + 30 wt% PC, whereas the complexation of the plasticizer within the nanocomposite electrolyte has been deduced from the detailed Fourier transform infrared spectroscopic investigation owing to the fact that such results have revealed the appearance of absorption bands corresponding to free triflate ions (CF3SO3−) and PC. Surface morphological features of pure PEO and (PEO)50AgCF3SO3:2 wt% SnO2 + 30 wt% PC nanocomposite systems were analysed through scanning electron microscope. The feasibility of a reduction in the degree of crystallinity of the plasticized system has been indicated by the X-ray diffraction data and confirmed from differential scanning calorimetric results obtained in terms of quantification of crystallinity and reduction in the glass transition temperature due to the addition of the chosen plasticizer into the nanocomposite polymer electrolyte matrix. Interestingly, the all solid-state cell based on the nanocomposite polymer electrolyte, namely, (PEO)50AgCF3SO3:2 wt% SnO2 + 30 wt% PC and silver anode has exhibited an open circuit voltage of 676 mV and short circuit current of 192 μA at room temperature.

Conductivity and dielectric behaviour of PEO-based solid nanocomposite polymer electrolytes

In this research, thin films of poly(ethylene oxide) (PEO) blend with lithium hexafluorophosphate (LiPF6) salt and ethylene carbonate (EC) as plasticiser and carbon nanotube (CNT) as filler, are prepared using solution casting method. The conductivity and dielectric response of the nanocomposite polymer electrolyte systems are studied within the broad frequency range of 5 Hz–5 MHz and within a temperature range of 298–373 K. The conductivity–temperature plots are observed to be of Arrhenius nature. The dielectric behaviour is analysed using the dielectric permittivity (εr and εi), loss tangent (tanδ) and electric modulus (Mi and Mr) of the samples. It is observed that the dielectric permittivity rises sharply towards low frequencies due to electrode polarisation effects. The maxima of the loss tangent (tanδ) shifts towards higher frequencies and the height of the peak increases with increasing temperature.

Investigation on ion conduction behaviour in Zn-ferrite based polymer nanocomposite electrolyte

Present paper deals with, improvement in ion transport property and dielectric relaxation of polyethylene oxide (PEO)-based polymer electrolytes subsequent to dispersal of nanosized Zn-ferrite filler particles. The nanocomposite polymer electrolyte (NCPE) system [93PEO:7NH4SCN]: x% Zn-ferrite was prepared by solution cast technique through dispersal of sol gel derived Zn-ferrite nano powder in the pristine polymer electrolyte solution. The structural and morphological behavior of NCPEs have been studied by XRD, SEM, IR and DSC measurements. Electrical conductivity (both a.c. & d.c.) measurement on nanocomposite polymer electrolyte sample have been carried out using impedance spectroscopic technique. Dielectric relaxation studies were extracted by impedance data. The hopping ion transport mechanism in NCPEs has been concluded with the help of dielectric and modulus formalism.

Conductivity studies of plasticized PEO–HPF6–fumed silica nanocomposite polymer electrolyte system

The effect of the addition of propylene carbonate (PC) on the ion transport behaviour of nanocomposite polymer electrolytes having composition of polyethylene oxide–hexafluorophosphoric acid–fumed silica has been studied. The ionic conductivity of 6.89 × 10−4 S cm−1 at 298 K has been obtained for these electrolytes along with good mechanical and thermal properties. The variation of 1H NMR linewidth with temperature shows line narrowing at the glass transition and melting temperature of the electrolytes which suggests the onset of long-range ion translational motion. The increase in ionic conductivity with the addition of PC is related to the transformation of these electrolytes to the amorphous phase which has been supported by X-ray diffraction results. The polymer electrolytes are thermally stable up to around 498 K and hence are suitable for various applications.

Neural networks for Nyquist plots prediction in a nanocomposite polymer electrolyte (PEO–LiPF6–EC–CNT)

In this study, the Nyquist plots for nanocomposite polymer electrolyte system (polyethylene oxide (PEO)–lithium hexafluorophosphate (LiPF6)–ethylene carbonate (EC)–carbon nanotube (CNT)), which was produced by using solution cast technique, were obtained using Bayesian neural network. First, to prepare the training and test set of the network, some results were experimental obtained and recorded. In the experiment, PEO, LiPF6, EC, and CNT were mixed at various ratios. The effects of the chemical composition on the impedance spectra of polymer electrolyte system were investigated. In neural network training, different chemical composition and real impedance were used as inputs and imaginary impedance in the produced polymer electrolytes was used as outputs. After the training process, the test data were used to check system accuracy. As a result, the neural network was found successful for the prediction of imaginary impedance of nanocomposite polymer electrolyte system.