Nanocomposite Gel Polymer Electrolytes Research Articles

Segmental mobility and relaxation processes of Fe2O3 nanoparticle-loaded fast ionic transport nanocomposite gel polymer electrolyte

The interaction of Fe2O3 nanoparticles emphasized between poly(propylene glycol) (PPG 4000) and silver triflate (AgCF3SO3) on the conformal changes of coordination sites and the electrochemical properties have been investigated. On the influence of Fe2O3 nanoparticles distribution, the interactions between the ether oxygen in C–O–C of the polymer chain with Ag+ ion as a result of bond strength of the C–O–C stretching vibration, the end group effect has been examined by Fourier transform infrared (FT-IR) spectroscopy. The formation of transient cross-links between polymer chains and filler particles appears to be a characteristic change in the glass transition temperature (T g) and enhance the effective number of cations as well. The strength of ion–polymer interactions was revealed by the transport of ions, t Ag+, and found to be in the range of 0.42–0.50, and the ionic conductivity was ascertained by complex impedance analysis with a maximum of 9.2 × 10−4 S cm−1 at 298 K with a corresponding concentration of 10 wt% Fe2O3 nanoparticles. The temperature dependence of conductivity has been examined based on the Vogel–Tammann–Fulcher (VTF) equation, thereby suggesting the segmental chain motion and free volume changes. From the impedance data, both the dielectric and modulus behaviours have been revealed and both were well correlated as a function of frequency.

Effect of nano-filler on the performance of multiwalled carbon nanotubes based electrochemical double layer capacitors

This article presents the main features of electrochemical double layer capacitor (EDLC), made up of multiwalled carbon nanotubes as electrode materials and electrolyte based on nano silica dispersed in poly(vinylidene fluoride-co-hexafluoropropylene)-based magnesium ion conducting nano composite gel polymer electrolyte. The capacitance value was stable up to 5000 voltammetric cycles and even more. The performance characteristics of EDLC have been tested using cyclic-voltammetry, impedance spectroscopy, and charge-discharge techniques. Analysis shows that the nano-filler based EDLC has relatively larger capacitance value as compared to filler-free based electrolyte. The maximum capacitance of 92 mF cm−2, equivalent to single electrode specific capacitance of 92 F g−1 was achieved. It corresponds to energy-density of 10.5 W h kg−1 and power-density of 3.25 kW kg−1.

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.

Experimental studies on high-performance supercapacitor based on nanogel polymer electrolyte with treated activated charcoal

Electrochemical capacitors, based on the double-layer capacitance of high specific surface area carbon materials, are attracting major fundamental and technological interest as highly reversible, electrical-charge storage and delivery devices, capable of being operated at high power densities. In the present paper, studies have been carried out on nanocomposite gel polymer electrolyte comprising poly(vinylidene fluoride-co-hexafluoropropylene)-propylene carbonate-magnesium perchlorate-nanofumed silica with a view to use them as electrolyte in electrochemical double-layer capacitors (EDLCs) based on chemically treated activated charcoal as electrodes. The optimized composition of nanogel polymer electrolyte exhibits high room-temperature ionic conductivity of 5.4 × 10−3 S cm−1 with good mechanical and dimensional stability which is suitable for their application as electrolyte in EDLCs. Detailed chemical and microstructural characterization of chemically treated and untreated activated charcoal was conducted using scanning electron microscopy and Brunauer–Emmett–Teller (BET). BET studies reveal that the effective surface area of treated activated charcoal powder (1,515 m2 g−1) increases by more than double-fold compared with untreated one (721 m2 g−1). Performance characteristics of EDLCs have been tested using cyclic voltammetry, impedance spectroscopy, prolonged cyclic test, and charge–discharge techniques. Analysis shows that the treated activated charcoal electrodes have almost five times more capacitance values as compared with the untreated one. The maximum capacitance of 324 mF cm−2, equivalent to single electrode specific capacitance of 216 F g−1 was achieved. It corresponds to an energy density of 20 Wh kg−1 and a power density of 2.2 kW kg−1.

Quasi‐Solid‐State Dye‐Sensitized Solar Cells Using Nanocomposite Gel Polymer Electrolytes Based on Poly(propylene carbonate)

AbstractPoly(propylene carbonate) (PPC) is synthesized from the copolymerization of CO2 and propylene oxide. Novel nanocomposite gel polymer electrolytes (GPEs) are prepared by utilizing PPC, organic solvents containing a redox couple, and aluminum oxide nanoparticles for application in dye‐sensitized solar cells (DSSCs). The quasi‐solid‐state DSSC assembled with optimized nanocomposite GPEs exhibits a relatively high conversion efficiency of 6.16% at 100 mW cm−2 and better stability than DSSC with liquid electrolyte.

Ionic transport studies in hyperbranched polyurethane/clay nanocomposite gel polymer electrolytes

In the present work, we report a novel nanocomposite gel electrolytes based on intercalation of hyperbranched polyurethane (HBPU) into organically modified montmorillonite for application in Li-ion batteries. The nanocomposites have been prepared by solution intercalation technique with varying clay loading. The formation of partially exfoliated nanocomposites has been confirmed by X-ray diffraction. Nanocomposites were soaked with 1 M LiCO4 in 1:1 (v/v) solution of propylene carbonate and diethyl carbonate to get the required gel electrolytes. AC impedance analysis shows that ionic conductivity increases with the increase of clay loading and attains the highest value of 8.3 × 10−3 S/cm for 5 wt.% clay concentration. Surface morphology of the nanocomposite electrolytes has been examined by SEM analysis. Improvement of electrochemical properties, viz., electrochemical potential window and interfacial stability, is also observed in the clay-loaded HBPU samples.

Electrical and structural studies on (PEO)50-AgCF3SO3: SnO2 nanocomposite gel polymer electrolyte materials

The present work deals with a new series of silver-ion conducting nanocomposite gel polymer electrolytes based on poly (ethylene oxide)50silver triflate, (PEO)50AgCF3SO3 incorporated with a nano-sized inorganic filler namely, SnO2 and a plasticizer, ethylene carbonate (EC) prepared using solution casting technique. Electrical conductivity measurements have been made on thin film polymer electrolyte systems containing (PEO50AgCF3SO3: 2wt% SnO2) + x wt% EC (x = 10, 15, 20, 25 and 30 respectively). It has been found that the room temperature ionic conductivity value enhanced from 3.1 × 10−6 to 5.4 × 10−5 S cm−1 on addition of EC into the chosen nanocomposite system PEO50AgCF3SO3: 2wt% SnO2. The apparent surface morphology has been examined through scanning electron microscopic (SEM) analysis. The occurrence of a reduction in the degree of crystallinity of the plasticized system has also been revealed from the observed X-ray diffraction (XRD) data.

Ionic conduction and phase separation studies in P(VdF-HFP))-LiClO4-dedoped polyaniline nanofiber composite polymer electrolytes — II: Effect of incorporation of PC and DEC

In the present work, ionic transport and interfacial stability of dedoped (insulating) polyaniline (PAni) nanofibers dispersed P(VdF-HFP) based nanocomposite gel polymer electrolytes have been investigated. Samples of P(VdF-HFP)-(PC+DEC)-LiClO4-x wt. % dedoped PAni nanofibers (x = 0, 2, 4, 6, 8, 10) are prepared by conventional solution casting technique. By analysis of SEM, XRD and impedance spectroscopy results it has been demonstrated that the incorporation of up to 6 wt. % of dedoped PAni nanofibers to P(VdF-HFP)-(PC+DEC)-LiClO4 polymer electrolyte system significantly enhances the ionic conductivity and interfacial stability of the electrolyte system. Above that concentration phase separation of PAni nanofibers is observed leading to decrease in ionic conductivity. The aggregated phase decreases the porosity, which results in lower ionic conductivity as confirmed by SEM. Experiments on the interfacial stability reveals that the stability of polymer electrolytes containing nanofibers is better than that of nanofiber free polymer electrolytes.

Electrical and electrochemical studies of poly(vinylidene fluoride)–clay nanocomposite gel polymer electrolytes for Li-ion batteries

A study is conducted on the electrical and electrochemical properties of nanocomposite polymer electrolytes based on intercalation of poly(vinylidene fluoride) (PVdF) polymer into the galleries of organically modified montmorillonite (MMT) clay. A solution intercalation technique is employed for nanocomposite formation with varying clay loading from 0 to 4 wt.%. X-ray diffraction results show the β phase formation of PVdF on intercalation. Transmission electron microscopy reveals the formation of partially exfoliated nanocomposites. The nanocomposites are soaked with 1 M LiClO 4 in a 1:1 (v/v) solution of propylene carbonate (PC) and diethyl carbonate (DEC) to obtain the required gel electrolytes. The structural conformation of the nanocomposite electrolytes is examined by Fourier transform infrared spectroscopy analysis. Examination with a.c. impedance spectroscopy reveals that the ionic conductivity of the nanocomposite gel polymer electrolytes increases with increase in clay loading and attains a maximum value of 2.3 × 10 −3 S cm −1 for a 4 wt.% clay loading at room temperature. The same composition exhibits enhancement in the electrochemical and interfacial properties as compared with that of a clay-free electrolyte system.

Electrical conductivity and dielectric behaviour of PPG4–AgCF3SO3:Al2O3 nanocomposite gel polymer electrolyte system

In this report, the synthesis of solvent-free poly(propylene glycol) 4000 (PPG4)–silver triflate (AgCF3SO3):xAl2O3 nanocomposite gel polymer electrolytes containing four different amounts of Al2O3 nanoparticles corresponding to x = 1, 3, 5 and 7 wt.%, respectively, with an ether oxygen-to-metal cation ratio (O–M) of 4:1 together with their vibrational spectroscopic characteristics derived from Fourier transform infrared (FT-IR ) spectroscopic analysis at room temperature (25 °C) is described. Furthermore, a detailed investigation concerning their mechanism of ion transport performed by means of complex impedance analysis in the frequency range 20 Hz to 1 MHz and over the temperature region 25–90 °C and analysed in terms of electrical conductivity spectra, electrical modulus spectra and impedance spectra has indicated that the typical composition PPG4–AgCF3SO3:5 wt.% Al2O3 would exhibit the best room temperature electrical conductivity of 6.2 × 10−4 S cm−1 owing to the mobility of coordinated silver cations through the mechanism of enhanced segmental motion of the PPG4 polymer chains as aided by the various coordinating sites available within the polymer network. It is also demonstrated from the present FT-IR results that significant changes in the intensity, shape and position of the different vibrational bands corresponding to –OH stretching, C–O–C stretching, C–H stretching and C–O–C in C–H stretching modes occur as a result of the incorporation of Al2O3 nanofiller particles into the PPG4–AgCF3SO3 complex. It is evident from the conductivity data that the observed enhancement in electrical conductivity would result from appropriate changes in ionic association occurring in the form of probable ion–ion and ion–polymer interactions involving Al2O3 nanofiller additive in accordance with the Lewis acid–base model of polymer–salt–filler interactions.

Enhanced ionic conductivity in oxygen ion irradiated poly(vinylidene fluoride-hexafluoropropylene) based nanocomposite gel polymer electrolytes

In the present work, effect of Swift Heavy Ion (SHI) irradiation by 90 MeV O 7+ ion with four different fluences on P(VdF − HFP)–(PC + DEC)–LiClO 4-dedoped (insulating) polyaniline (PAni) nanofibers polymer electrolytes have been investigated. The irradiated films have been investigated by ac impedance, XRD, FTIR, DSC and SEM analyses. It has been observed that irradiation with swift heavy ion shows increase in ionic conductivity of the composite gel polymer electrolyte films at lower fluences (≤10 11 ions/cm 2) and decrease at higher fluences (≥10 11 ions/cm 2) as compared to the unirradiated film. Maximum ionic conductivity of 1.2 × 10 − 2 S/cm at room temperature has been found after irradiation with fluence 10 11 ions/cm 2. The increase in ionic conductivity at lower fluences could be attributed to the scissioning of polymer bonds, which leads to larger segmental motion of polymer backbone resulting in faster ionic transport through the polymer matrix. However at higher fluences (≥10 11 ions/cm 2) the polyaniline nanofibers get phase separated out from P(VdF − HFP)–(PC + DEC)–LiClO 4 leading to decrease in ionic conductivity. The phase separation phenomenon has been confirmed by DSC, FTIR and dielectric loss spectra. The surface morphology of the irradiated films has been examined by SEM.

Enhanced ionic conductivity in novel nanocomposite gel polymer electrolyte based on intercalation of PMMA into layered LiV3O8

In the present work, a novel polymer electrolyte based on poly(methyl methacrylate) (PMMA)/layered lithium trivanadate (LiV3O8) nanocomposite has been investigated. X-ray diffraction (XRD) study shows that d-spacing is increased from 6.3 ± 0.1 A to 12.8 ± 0.1 A upon intercalation of the polymer into the layered LiV3O8. Room temperature ionic conductivity of the obtained nanocomposite gel polymer electrolyte is found to be superior to that of conventional PMMA-based gel polymer electrolyte. Enhancement in ionic conductivity of the nanocomposite gel electrolyte is attributed to the formation of a two-dimensional channel as a result of decreased interaction between Li+ and V3O8− layers as confirmed by FTIR. SEM results show aggregation of nanocomposite particles resulting from extension of some of the polymer chains from interlayer to the edge providing paths for Li+ ion transport. Interfacial stability of nanocomposite gel electrolyte is also found to be better than that of the conventional PMMA-based gel polymer electrolyte.

Enhanced electrical and electrochemical properties of PMMA–clay nanocomposite gel polymer electrolytes

In the present work, effect of organically modified montmorillonite (MMT) clays on PMMA-based electrolytes has been investigated. The nanocomposites have been prepared by solution intercalation technique with varying clay loading from 0 to 5 wt.%. The formation of partially exfoliated nanocomposites has been confirmed by XRD and TEM analyses. The obtained nanocomposites were soaked with 1 M LiClO 4 in 1:1 (v/v) solution of propylene carbonate (PC) and diethyl carbonate (DEC) to get the required gel electrolytes. Surface morphology and structural conformation of the nanocomposite electrolytes have been examined by SEM and FTIR analyses, respectively. It has been observed that the ionic conductivity of the nanocomposite gel polymer electrolytes increases with the increase in clay loading and attains a maximum value of 1.3 × 10 −3 S/cm at room temperature as revealed by ac impedance spectroscopy. Improvement of electrochemical and interfacial stabilities has also been observed in the gel electrolytes containing MMT fillers.

Structure and properties of an organic rectorite/poly(methyl methacrylate) nanocomposite gel polymer electrolyte by in situ synthesis

AbstractThe synthesis of organic‐modified rectorite (OREC)/polymethyl methacrylate (PMMA) nanocomposite gel polymer electrolyte (NGPE) via in situ polymerization was investigated using free radical initiator in an solution, in which organic plasticizer, propylene carbonate(PC) acted as a solvent. A serious of NGPE membranes with different OREC content were prepared and characterized. The dispersion and exfoliation statuses of the OREC in the prepared NGPE membranes were analyzed through X‐ray diffraction (XRD) and transmission electron microscope (TEM), and the results indicated that for the NGPE with 5 wt % OREC membrane, OREC was partly exfoliated and well dispersed in the gel polymer electrolyte system. The electrochemical properties of the NGPE were determined by alternating current (AC) impedance spectroscopy, which illustrated that the ionic conductivity of the nanocomposite gel polymer electrolyte firstly increased and then decreased with increasing OREC content. Meanwhile, the maximum value of ionic conductivity for nanocomposite gel polymer electrolytes was obtained when organic clay amount was 5 wt %. The interactions among the components of the NGPE were investigated by Fourier transform infrared (FTIR) spectroscopy. It was shown that there were specific interactions between OREC and the other components, which may influence the conductivity and the stability of GPEs. Finally, an thermal stability enhancement was presented by NGPE with 5 wt % OREC compared with GPE, which was determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

A study on LiBOB-based nanocomposite gel polymer electrolytes (NCGPE) for Lithium-ion batteries

Lithium bis(oxalato)borate (LiBOB) salt-based nanocomposite gel polymer blend electrolyte (PVdF/PVC) membranes have been prepared by solution casting technique for various concentrations of TiO2. The effect of anatase structure of nanosized titanium dioxide in the plasticized PVC/PVdF + LiBOB matrix has been observed in the 2:1 salt filler ratio in the impedance measurements that the conductivity is increased one order of magnitude higher than the filler-free electrolyte (1:0 salt:filler ratio). The phase morphology of this electrolyte membrane represents the appearance of the free volume sites for ionic migration.