Plasticized Polymer Electrolytes Research Articles

UV-cured Al2O3-laden cellulose reinforced polymer electrolyte membranes for Li-based batteries

A methacrylate based plasticised polymer electrolyte membrane is prepared via a rapid and facile UV curing process, the major concerns of mechanical integrity are overcome by simply using appropriately modified cellulose handsheet laden with nano-sized acidic alumina particles as a reinforcement. The use of the cellulose handsheets greatly enhances the flexibility and mechanical properties of the membrane while the addition of alumina particles helps to maintain satisfactory conductivity values. The reinforced composite electrolyte membrane is also tested in a real lithium cell, exhibiting excellent performance which account for its use in futuristic lithium batteries having low cost, environmentally friendly and easily scalable properties.

Effect of nanofiller CeO2 on structural, conductivity, and dielectric behaviors of plasticized blend nanocomposite polymer electrolyte

A novel combination of nanoparticles of rare earth oxide ceria (CeO2) dispersed in polyethylene oxide (PEO)/polyethylene glycol (PEG) blend polymer doped with cation donor salt lithium perchlorate (LiClO4), and ethylene carbonate (EC) nanocomposite polymer electrolyte (NCPE) was prepared by standard solution casting technique. The X-ray diffraction (XRD) patterns reveal that the amorphous nature of the nanocomposite has been increased considerably on dispersion of nanofiller. The complexation was further confirmed by Fourier transform infrared (FTIR) analysis. The impedance spectroscopy technique was used to measure the ionic conductivity and activation energy of the nanocomposite electrolytes. The maximum ambient temperature conductivity of 1.18 × 10−4 Scm−1 was obtained for the nanocomposite of 68 % PEO, 16 % PEG, 11 % LiClO4, 5 % EC, and 1 % CeO2 by weight percentage. The ac conductivity follows the universal power law. The variation of dielectric permittivity, dielectric loss, and modulus spectra with frequency and temperature was consistent with conductivity. The activation energy calculated from temperature-dependent imaginary modulus well coincides with that of conductivity. The loss tangent ascertains the presence of conductivity relaxation and the minimum relaxation time for highest conducting electrolyte.

Impedance and structural studies on plasticized PCL-LiSO3CF3-SiO2 polymer electrolytes.

Plasticized polymer electrolytes in this study are consist of biodegradable polycaprolactone (PCL) as a host, ethylene carbonate (EC) as a plasticizer, lithium triflate (LiSO3CF3) as salt and nanocomposite silicon dioxide (SiO2) as filler. Solution cast technique is used in the preparation of the plasticized polymer electrolytes. The electrical properties of the plasticized polymer electrolytes with different composition of lithium salt, plasticizer and nano-sized filler are reported in this paper. Conductivity as high as 4.30 x 10(-3) S cm(-1) is obtained in ambient temperature. Ionic conductivity of the plasticized polymer electrolytes are measured using electrochemistry impedance spectroscopy (EIS). The structural and complex formations are studied by X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy. The ionic conductivity result can be further verified and supported by XRD and FTIR reading in which the ionic conductivity is directly proportional to the amorphous phase behaviour of the sample.

Effect of Plasticizers on Structural and Dielectric Behaviour of [PEO + (NH4)2C4H8(COO)2] Polymer Electrolyte

Improvements in ion transport property of polyethylene-oxide- (PEO-) based polymer electrolytes have been investigated, using different types of plasticizers. The effects of single and coupled plasticizers [i.e., EC, (EC + PC), and (EC + PEG)] on structural and electrical behavior of pristine electrolyte were studied by XRD, SEM technique, and impedance spectroscopy. The electrical conductivity of the best plasticized system was found to be 4 × 10−6 S/cm. Argand plots show dispersive nature of relaxation time or inhomogeneous space charge polarization of plasticized polymer electrolyte.

Role of Different Plasticizers in Li-Ion Conducting Poly(Acrylonitrile)-Poly(Methyl Methacrylate) Hybrid Polymer Electrolyte

In this work, polymer electrolytes composed of PAN/PMMA/LiClO4 with different plasticizers are prepared using solvent casting technique. Ionic conductivity of the electrolytes is evaluated with the help of ac impedance study at various temperatures. Structural and the complexation of the prepared electrolytes are studied by XRD and FTIR analysis, respectively. Thermogravimetric/differential thermal analysis (TG/DTA) is used to find the thermal stability of the polymer electrolytes. PAN/PMMA/EC/LiClO4-based plasticized polymer electrolyte is found to possess optimal properties in terms of conductivity and thermal stability. Porous nature of the polymer gel electrolytes is also confirmed by SEM analysis.

Effect of succinonitrile and nano-hydroxyapatite on ionic conductivity and interfacial stability of polyether-based plasticized nanocomposite polymer electrolytes (PNCSPE)

A series of novel plasticized nanocomposite solid polymer electrolytes (PNCSPE) consisting of polyethylene oxide as polymer host, lithium bisoxalatoborate as salt with different weight ratios of succinonitrile and nano-hydroxyapatite was prepared by membrane hot-press technique. The electrical property of PNCSPE was investigated by AC impedance analysis. The migration of lithium ion in the polymer matrix was confirmed from cyclic voltammetry study. The incorporation of different compositions of filler and plasticizer in the polymer matrix significantly enhanced the amorphous nature resulted in increase in ionic conductivity of PNCSPE. The maximum ionic conductivity was found to be in the order of 10−3.1 S/cm.

Influence of carbon nanotubes on the optical properties of plasticized solid polymer electrolytes

Polyethylene oxide (PEO) based solid polymer electrolyte films complexed with lithium hexafluorophosphate (LiPF6), ethylene carbonate (EC) and carbon nanotubes (CNTs) are prepared by solution-casting technique. The complexation of doping materials with polymer is confirmed by X-ray diffraction and infrared studies. The incorporation of LiPF6, EC and CNTs into the host polymer shows a significant increase in conductivity of 10−10 and 10−3Scm−1. The optical properties such as direct and indirect band gaps are investigated for pure and doped polymer films within a wavelength range of 200–400nm. It is found that the energy gaps and band edge values shift towards lower energies upon doping. It is shown that LiPF6, EC and CNTs are responsible for the formation of defects in polymer electrolytes, which increases the degree of disorder in the films.

Effect of Electron Beam Irradiation on the Mechanical and Electrochemical Properties of Plasticized Polymer Electrolytes Dispersed with Nanoparticles

The effect of electron beam irradiation on electrical, thermal, mechanical and morphological properties of plasticized polymer electrolytes was investigated. A significant improvement in the mechanical strength without reduction in ionic conductivity was observed for the irradiated polymer electrolytes. DSC studies showed that the thermal behavior of the polymer electrolytes was improved by the addition of filler and by irradiation. SEM studies revealed a significant improvement in surface morphology of the polymer electrolyte after irradiation. The results are presented herein.

Studies of a plasticized PEO + NH4PF6 proton-conducting polymer electrolyte system and its application in a proton battery

We have synthesized polyethylene oxide (PEO) + NH4PF6 polymer electrolyte films plasticized with ethylene carbonate (EC) and a mixture of ethylene carbonate and propylene carbonate (EC/PC) by using a solution cast technique. X-ray diffraction (XRD) results show a decrease in crystallinity from ∼67% in the unplasticized complex to 39% and 35% in the EC- and the EC/PC-plasticized complexes, respectively. Scanning electron microscopy (SEM) results show the formation of a fringed miscellar structure in the plasticized complexes. An increased coordination between dissociated ions and the ether oxygen of PEO on plasticization is established from the Fourier transform infrared (FTIR) studies. The ionic conductivity shows an enhancement of about two orders of magnitude on plasticization. The room-temperature ionic conductivities of the highest conducting compositions are obtained as ∼1.52 × 10−5 S cm−1 and ∼1.03 × 10−5 S cm−1 in the EC- and the EC/PC-plasticized complexes, respectively. The highest conducting compositions of plasticized polymer electrolyte films are used to fabricate proton batteries with the configuration Zn/ZnSO4.7H2O (anode) ‖Polymer electrolyte‖ PbO2/V2O5 (cathode), and different battery parameters are reported.

Electrical double-layer capacitors with plasticized polymer electrolyte based on methyl cellulose

Poly(ethylene glycol) plasticized polymer electrolytes based on methyl cellulose have been prepared using the solution casting technique. Interactions between component materials in the electrolyte have been examined using Fourier transform infrared spectroscopy. The polymer-salt spectrum indicates that interaction occurred at the oxygen atom with the shift of the C–O stretching mode. Inference from the Nyquist plot suggests that the material can be represented by a resistor connected in series with a constant phase element. Capacitance evaluated from the fitting equation representing impedance of the equivalent circuit is observed to decrease with increasing temperature. From linear sweep voltammogram, the 63.75 wt% MC-21.25 wt% NH4NO3-15 wt% PEG, which is the highest conducting plasticized sample shows good electrochemical stability. This material has been tested as an electrolyte in electrical double-layer capacitor fabricated in this study. The electrochemical properties of the capacitors have been investigated by cyclic voltammetry, charge-discharge, and self-discharge characteristics. The discharge capacitance obtained is 38 F g−1.

Conductivity Study on PEO Based Polymer Electrolytes Containing Hexafluorophosphate Anion: Effect of Plasticizer

AbstractPEO based polymer electrolytes containing ammonium hexafluorophosphate (NH4PF6) and hexafluorophosphoric acid (HPF6), both with PF anion have been studied. The effect of the addition of propylene carbonate (PC) to PEO‐NH4PF6 and PEO‐HPF6 has been observed to increase in ionic conductivity which is attributed to an increase in free ion concentration due to the dissociation of ion aggregates present at higher acid/salt concentrations. The plasticized polymer electrolytes containing HPF6 show relatively higher conductivity (σmax = 1.02 × 10−4 S/cm at 10 wt% HPF6) as compared to electrolytes containing NH4PF6 (σmax = 1.09 × 10−5 S/cm at 10 wt% NH4PF6). Presence of free ions, ion aggregates and their dissociation with the addition of PC has been studied by Fourier Transform Infrared Spectroscopy (FTIR). The change in amorphous phase with PC content was also studied by X‐Ray Diffraction (XRD). The variation of conductivity with temperature shows Vogel–Tammen–Fulcher (VTF) behavior, which is associated with the highly amorphous nature of electrolytes. 1H Nuclear magnetic Resonance (NMR) spectra at different temperatures shows line narrowing and suggests the onset of long range ion diffusional motion. Change in surface morphology of polymer electrolytes with the addition of PC is also checked by Scanning Electron Microscopic (SEM) studies.

Improved performance using a plasticized polymer electrolyte for quasi-solid state dye-sensitized solar cells

A PEO/P(VDF-HFP) polymer-blend electrolyte is modified by different amounts of LiN(SO2CF3)2 (lithium bis(trifluoromethanesulfone)imide, LiTFSI). Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC) are carried out to examine the configuration changes of the polymer electrolyte. LiTFSI acts as a plasticizer influencing the ionic conductivity of the LiTFSI-modified polymer electrolyte, and improves the short-circuit photocurrent effectively. The electrochemical impedance spectroscopy (EIS) indicates that the intercalation or adsorption of overdose Li+ to the TiO2 photoanode surface positively changes the Fermi energy level and the conduction band. This improves the interface recombination in the DSSC and reduces the open-circuit voltage. With moderate LiTFSI content (0.05g, nKI/nI2=7:1) modification, the DSSC exhibits a 1.6mAcm−2 improvement of current density and an improved performance of 5.03% compared with 4.51% of the original DSSC.

Temperature dependence of the conductivity of plasticized poly(vinyl chloride)-low molecular weight liquid 50% epoxidized natural rubber solid polymer electrolyte

Characterizations were carried out to study on a new plasticized solid polymer electrolyte that was composed of blends of poly(vinyl chloride) (PVC), liquid 50% epoxidized natural rubber (LENR50), ethylene carbonate, and polypropylene carbonate. This freestanding solid polymer electrolyte (SPE) was successfully prepared by solution casting technique. Further analysis and characterizations were carried out by using scanning electron microscopy (SEM), X-ray diffraction, differential scanning calorimeter (DSC), Fourier transform infrared (ATR-FTIR), and impedance spectroscopy (EIS). The SEM results show that the morphologies of SPEs are compatible with good homogeneity. No agglomeration was observed. However, upon addition of salt, formation of micropores occurred. It is worth to note that micropores improve the mobility of ions in the SPE system, thus increased the ionic conductivity whereas the crystallinity analysis for SPEs indicates that the LiClO4 salt is well complexed in the plasticized PVC-LENR50 as no sharp crystallinity peak was observed for 5–15% wt. LiClO4. This implies that LiClO4 salt interacts with polymer host as more bonds are form via coordination bonding. In DSC study, it is found that the glass temperature (Tg) increased with the concentration of LiClO4. The lowest Tg was obtained at 41.6 °C when incorporated with 15% wt. LiClO4. The features of complexation in the electrolyte matrix were studied using ATR-FTIR at the peaks of C=O, C–O–C, and C–Cl. In EIS analysis, the highest ionic conductivity obtained was 1.20 × 10−3 S cm−1 at 15% wt. LiClO4 at 353 K.

Effect of propylene carbonate and dimethylformamide on ionic conductivity of P(ECH-EO) based polymer electrolyte

The new plasticized polymer electrolyte composed of poly(epichlorohydrin-ethyleneoxide) (P(ECH-EO)) as host polymer, mixture of γ-butyrolactone (γ-BL) and propylenecarbonate (PC), γ-butyrolactone (γ-BL) and dimethylformamide (DMF) as plasticizer and lithium perchlorate (LiClO4) as salt were prepared by simple solution casting technique. The structure and the surface morphological characterization were studied by X-ray diffraction (XRD) and polarized optical microscopic (POM) measurements respectively. Differential scanning calorimetry (DSC) analysis was carried out on the plasticized polymer electrolyte to observe the change in transition temperature caused by the addition of two different plasticizers (PC and DMF). The thermal stability of the plasticized polymer electrolyte was studied by TG/DTA and found as the plasticizer content increases the thermal stability of the film decreased. Impedance spectroscopy technique was used to study the mode of ion conduction in the plasticized polymer electrolyte. The highest ionic conductivity is found to be 5.8×10−4Scm−1 at 303K for DMF plasticized polymer electrolyte. The electrochemical stability of the plasticized polymer electrolyte has been studied by cyclic voltammetry using aluminum (Al) as the blocking electrodes. The films were found to be electrochemically stable till 1.2V.

Effect of Nano-Filler on Structural and Ionic Transport Properties of Plasticized Polymer Electrolyte

Polymer blend electrolytes, where PEO-PMMA polymer blend is used as polymer host matrix, doped with AgNO3 and plasticized with ethylene carbonate (EC) and Al2O3 as nano-filler were synthesized using the solution cast techniques. The polymer films were characterized by impedance spectroscopy, XRD, DSC, SEM, FT-IR and ionic transport mea-surements. The results indicate an enhancement in conductivity of PEO-PMMA-AgNO3-EC polymer electrolytes. The ionic conductivity of the polymer films is also found to increase with temperature. Electrical properties of polymer films in the framework of dielectric and modulus formalism are studied and discussed

Resistive-type Humidity Sensor Based on CA-NH4BF4-PEG600 Thin Films

Abstract The resistive-type humidity sensor was prepared by using dip-coating method based on CA-NH4BF4-PEG600 plasticized polymer electrolytes film on a glass substrate. The electrical properties of the film are examined as a function of relative humidity to elucidate the potential of the film act as sensory properties in humidity sensor. The sensor well responded towards humidity with a relatively good in linearity though it is depended on the applied frequency. The temperature dependence of resistance followed Arrhenius law and the activation energy decreased with increasing in relative humidity. The hysteresis phenomenon showed the resistance on desiccation process is slightly lower than the resistance on humidification process at all temperatures. The stability of fabricated humidity sensor stabled up to 30 days.

Laser Raman and conductivity studies of plasticized polymer electrolyte P(ECH-EO):propylenecarbonate:γ-butyrolactone:LiClO4

The plasticized polymer electrolytes composed of poly(epichlorohydrin-ethyleneoxide) (P(ECH-EO)) as host polymer, lithium perchlorate (LiClO4) as salt, γ-butyrolactone (γ-BL), and propylene carbonate (PC) as plasticizer have been prepared by simple solution casting technique. The effect of mixture of plasticizers γ-BL and PC on conductivity of the polymer electrolyte P(ECH-EO):LiClO4 has been studied. The band at 457 cm−1 in the Raman spectra of plasticized polymer electrolyte is attributed to both the ring twisting mode of PC and the perchlorate ν2(ClO4−) bending. The maximum conductivity value is observed to be 4.5 × 10−4 S cm−1 at 303 K for 60P(ECH-EO):15PC:10γ-BL:15LiClO4 electrolyte system. In the present investigation, an attempt has been made to correlate the Raman and conductivity data.

Effect of Plasticizers on Ion Transport Properties of PEO+NH4PF6 Polymer Electrolyte System – Dielectric Studies

Dielectric properties of proton conducting polymer electrolyte system, containing polyethylene oxide (PEO) as host polymer and ammonium hexfluorophosphate (NH4PF6) as complexing salt plasticized with EC and EC:PC, are investigated. The free standing films of thickness ~ 200 - 300µm are synthesized by solution casting technique. The electrical conductivity studies show that plasticization of the polymer electrolyte results into an enhancement in its conductivity by about two orders of magnitude. The maximum room temperature bulk conductivity is obtained to be ~ 10-5 S/cm for the plasticized polymer electrolyte. To understand the ion transport mechanism, different frequency dependent parameters are measured like dielectric permittivity, loss tangent and AC conductivity. The ionic transference number of the prepared systems is found to be close to unity which shows ion dominant charge transport in the electrolyte system. The conductivity of the polymer electrolyte has been found to be very sensitive to the relative humidity, which makes it a good candidate for its application for humidity sensor.

Conductivity, thermal and infrared studies on plasticized polymer electrolytes with carbon nanotubes as filler

New composite polymer electrolytes (CPE) are prepared using solution-casting technique. The CPE are based on polyethylene oxide (PEO) and employ lithium hexafluorate (LiPF6) as the doping salt, ethylene carbonate (EC) as the plasticizer and amorphous carbon nanotubes (αCNTs) as the filler. The crystallinity and ionic conductivity of the CPE are examined in this work. The conductivity increases from 10−10 to 10−5Scm−1 upon the addition of salt. The incorporation of EC and αCNTs into the salted polymer enhances the conductivity significantly to 10−4 and 10−3Scm−1. The Vogel–Tamman–Fulcher (VTF) plots suggest that the temperature dependence of conductivity is a thermally activated process. Differential Scanning Calorimetry (DSC) studies show that the melting transition temperature and crystallinity decrease upon the addition of salt, EC and αCNTs into the polymer electrolyte system. The complexation, nature and concentration of the various ionic species are examined using Fourier Transform Infrared Spectroscopy (FTIR). Scanning electron microscopy (SEM) images show the changes in morphologies of the composite polymer electrolytes. The application of CPE especially in batteries and the advantages of this composite are highly conductive and stable at elevated temperature.

Conductivity and optical studies of plasticized solid polymer electrolytes doped with carbon nanotube

Solid polymer electrolyte films based on Poly(ethylene oxide) (PEO) complexed with lithium hexafluorophosphate (LiPF 6), ethylene carbonate (EC) and amorphous carbon nanotube (αCNTs) were prepared by the solution cast technique. The conductivity increases from 10 −10 to 10 −5 Scm −1 upon the addition of salt. The incorporation of EC and αCNTs to the salted polymer enhances the conductivity significantly to 10 −4 and 10 −3 Scm −1. The complexation of doping materials with polymer were confirmed by X-ray diffraction and infrared studies. Optical properties like direct band gap and indirect band gap were investigated for pure and doped polymer films in the wavelength range 200–400 nm. It was found that the energy gaps and band edge values shifted to lower energies on doping.