Polymer Electrolyte Films Research Articles

Ultrathin polymer electrolyte film prepared by in situ polymerization for lithium metal batteries

Polymer materials demonstrate tremendous potential in constructing high-performance solid-state lithium metal batteries (LMBs). However, the polymer-based solid-state batteries assembled via the ex situ process generally exhibit poor electrolyte/electrode interfacial contact. Herein, we report an in situ solidification method based on ring-opening polymerization of ε-caprolactone (ε-CL), which enables an ultrathin film (11 μm) as solid polymer electrolytes (SPEs). Thanks to the mild reaction conditions and simple process, such SPEs are obtained efficiently and exhibit intimate interfacial contact with electrodes. It is worth noting that the initiator—stannous octoate—can react with the lithium metal anode to form a LiSn alloy layer, which possesses excellent lithium dendrite resistance. The addition of 15 wt% propylene carbonate leads to a semisolid-state battery with further improved ionic conductivity, which manifests outstanding cell performance at both 60 °C and room temperature. As a result, the semisolid-state LiFePO4/Li cell delivers a high discharge capacity of 150 mAh/g even after 100 cycles at room temperature, further highlighting the enhanced interfacial stability after the in situ solidification of ε-CL on the electrode surface. It is believed that such an in situ polymerization process to prepare polymer electrolytes has great potential for building the better solid-state LMBs.

Investigations on Structural, Optical Properties, Electrical Properties and Electrochemical Stability Window of the Reduced Graphene Oxides Incorporated Blend Polymer Nanocomposite Films.

The incorporation of reduced Graphene oxides (rGO) as a nanofiller in the blend polymer nanocomposite (BPNC) based on Polyvinylpyrrolidone (PVP)-Polyvinylalcohol (PVA) and sodium bicarbonate (NaHCO₃) are presented. The blend polymer electrolytes films are prepared by the standard solution cast technique, and it is characterized to investigate the structural, morphological, thermal, optical and electrochemical property. The X-ray diffraction confirms the formation of polymer nanocomposite and is agreed with FESEM analysis. The FTIR confirms the presence of various interactions between the polymer, salt and rGO, and indicates the composite formation. The DSC examines the thermal property of the blend polymer nanocomposite electrolytes system. The bandgap energy has been obtained from the UV-spectroscopy and examines the direct and indirect gap, both offer the decreases bandgap with the addition of a higher concentration of rGO as nanofillers. The highest value of ionic conductivity of the film is obtained ~1.39×10-6 S cm-1 at 15 wt.% of rGO content in polymer blend nanocomposite (BPNC) films. For these BPNC films, the electrochemical stability window (ESW) is ~4.0 V at 25 wt.% of rGO content and ionic transport number (tion) is ~0.98, for 10 wt.% of rGO content at the room temperature. These highly stable blend polymer nanocomposite electrolyte films offer the excellent properties for utilized as a separator for solid-state devices e.g., battery, supercapacitors, electrochromic display devices and other electrochemical energy storage/ conversion devices respectively.

Enhanced electrochemical performance of garnet-based solid-state lithium metal battery with modified anodic and cathodic interfaces

Due to high ionic conductivity and wide electrochemical window, the garnet solid electrolyte is considered as the most promising candidate electrolyte for solid-state lithium metal batteries. However, the high contact impedance between metallic lithium and the garnet solid electrolyte surface seriously hampers its further application. In this work, a Li-(ZnO) x anode is prepared by the reaction of zinc oxide with metallic lithium and in situ coated on the surface of Li 6.8 La 3 Zr 1.8 Ta 0.2 O 12 (LLZTO). The anode can be perfectly bound to the surface of LLZTO solid electrolyte, and the anode/electrolyte interfacial resistance was reduced from 2319 to 33.75 Ω·cm 2 . The Li-(ZnO) 0.15 |LLZTO|Li-(ZnO) 0.15 symmetric battery exhibits a stable Li striping/plating process during charge-discharging at a constant current density of 0.1 mA·cm −2 for 100 h at room temperature. Moreover, a Li-(ZnO) 0.15 |LLZTO-SPE|LFP full battery, comprised of a polyethylene oxide-based solid polymer electrolyte (SPE) film as an interlayer between LiFePO 4 (LFP) cathode and LLZTO solid electrolyte, presents an excellent performance at 60 °C. The discharge capacity of the full battery reaches 140 mA·h·g −1 at 0.1 C and the capacity attenuation is less than 3% after 50 cycles.

Study of the Thermal Stability and Ionic Conductivity of Polystyrene-Co-Acrylonitrile Based Composite Solid Polymer Electrolytes Incorporated with different Lithium Salts

In the present study, a series of poly(styrene-co-acrylonitrile) (SAN) polymer electrolytes and SAN- poly(vinyl alcohol) (PVA) polymer blend electrolytes were prepared with different lithium salts using a solvent casting technique. TG & DSC studies were carried out to investigate the thermal stability of the polymer blend electrolytes. Ionic conductivities of these electrolytes were measured by AC impedance spectroscopy. Results for conductivity studies have shown that the polymer with SAN/PVA complex with 5 % LiBr exhibits the highest conductivity of 8.7 × 10−5 S/cm at 70°C. The temperature dependence of the polymer electrolyte films obeys Arrhenius relation.

Synthesis, optical properties, and impedance spectroscopy of Na2TeO3 doped polyvinyl alcohol as novel polymeric electrolyte films

Synthesis, optical properties, and impedance spectroscopy of Na2TeO3 doped polyvinyl alcohol as novel polymeric electrolyte films

Preparation and electrochemical properties of polymer electrolyte containing lithium difluoro(oxalato)borate or lithium bis(oxalate)borate for Li-ion polymer batteries

A lithium difluoro(oxalato)borate (LiODFB) and lithium bis(oxalate)borate (LiBOB) salts in combination with an ionic liquid (N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulphonyl)imide - MePrPyrNTf2 or 1-ethyl-3-methylimidazolium bis(trifluoromethanesulphonyl)imide - EtMeImNTf2), sulfolane (TMS) and poly(vinylidene fluoride) (PVdF) were tested as polymer electrolytes (PEs) for Li-ion polymer batteries. Quaternary lithium salt (LiBOB or LiODFB) + ionic liquid (EtMeImNTf2 or MePrPyrNTf2) + PVdF + TMS polymer electrolytes were prepared by the casting technique. All the membranes are free-standing, flexible and transparent. Obtained PE films were investigated by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and the flammability test. Conductivity of the polymer electrolytes ranged from 0.52 to 3.21 mS cm−1 with the activation energy of 34.24 and 19.58 kJ mol−1, respectively. Decomposition of PE does not result in flammable products. The presence of large pores in these membranes ensures better lithium ion transport processes. The polymer electrolytes were used as electrolytes in Li|LiFePO4 and Li|Li cells which were tested applying EIS, cyclic voltammetry and the galvanostatic method. The electrochemical formation of SEI protects the Li| polymer electrolyte system against its aging (the total impedance evolution with time is much smaller). The LiFePO4 cathode with the membrane (24.7 wt% PVdF, 2.3 wt% LiODFB, 51.1 wt% EtMeImNTf2 and 21.9 wt% TMS) exhibited a good reversible capacity of 138 mAh g−1 and 120 mAh g−1 at high current densities (the C/2 and 1C rates).

Dielectric relaxations and ion transport study of NaCMC:NaNO3 solid polymer electrolyte films

Na+ ion-conducting solid polymer electrolyte (SPE) of sodium salt of carboxymethyl cellulose (NaCMC) doped with sodium nitrate (NaNO3) was developed by solution casting method. FTIR technique confirmed the formation of hydrogen bonding between {NO}_3^{-} anion and functional groups of NaCMC. XRD study revealed the low degree of crystallinity that reduced upon doping. Impedance spectroscopy was adapted in order to analyze the conductivity and dielectric relaxation phenomena of the polymer-salt complex. FTIR deconvolution technique was employed to understand the factor that influences the ionic conductivity in SPE; concentration of mobile ions and ionic mobility both play a vital role. Ion transference number has been found out to be > 0.97 for all samples indicating that the conducting species are primarily ions. The highest ionic conductivity of ̴ 3 × 10−3 Scm−1 with the mechanical strength of 30.12 MPa was achieved for a host containing 30 wt.% NaNO3 at ambient temperature.

High conducting PVDF-HFP + PTA polymer electrolyte for supercapacitor application

Herein, we reported the synthesis of polymer electrolyte prepared using polymer PVDF-HFP and PTA doped using well known solution cast technique method. There was a huge hike in the conductivity recorded while incorporating of PTA with polymer PVDF-HFP which was scrutinized by complex impedance spectroscopy. Fourier transform infrared spectroscopy was done to check the complexity of blended polymer PVDF-HFP with PTA. Polarized optical microscopy was also done to check the amorphousity of the polymer electrolyte. A good stable Electric double layer capacitor was fabricated using optimized polymer electrolyte film which shows reasonable efficiency.

Development of bio-degradable based polymer electrolytes for EDLC application

In this work, bio-degradable blended solid polymer electrolyte (BSPE) films made up of PVA:PS:(CH3COO)2Mg with different wt% ratios 50:50:00, 40:40:20, 35:35:30 and 30:30:40, prepared using solution casting technique at room temperature. The physical and chemical properties of the prepared BSPE films were done using XRD, FTIR, UV–vis spectroscopy, TGA and SEM techniques. The electrical properties were measured using impedance analyzer. The highest conductivity 6.28 × 10−4 S/cm and the highest energy band gap 3.52 eV observed for the BSPE film with ratio at room temperature was. The charge storage capability of the material was analysed using dielectric analysis. Cyclic voltammetry (CV) analysis of PVA:PS:(CH3COO)2Mg (35:35:30 wt%) BSPE film showed specific capacitance value as 2 F/g, energy density value as 8.68 W h kg-1 and power density value as 312 W kg-1 respectively.

Ionic Conductivity and Structural Properties for CMC - AN in Propylene Carbonate as Plasticizer in Solid Biopolymer Electrolytes

The present study aims to investigate the structural and ionic conductivity of carboxymethyl cellulose (CMC) - ammonium nitrate (AN) – propylene carbonate (PC) as proton conducting polymer electrolytes. The CMC-AN-PC were prepared via solution casting technique. The complexion of polymer electrolyte films has been confirmed via FTIR studies. Fourier transform infrared (FTIR) spectra showed the occurrence of complexation between the polymer electrolyte components. Impedance studies reveals that the highest ionic conductivity of CMC-AN-5wt% PC 6.5 × 10−3 Scm−1 was observed in polymer electrolyte system obtained at ambient temperature.

Effect of TiO2 Nano-Filler on Electrical Properties of Na+ Ion Conducting PEO/PVDF Based Blended Polymer Electrolyte

Nanocomposite polymer electrolyte (NCPE) films based on a blend of two polymers poly (ethylene oxide) (PEO) and poly (vinylidene fluoride) (PVDF) complexed with sodium perchlorate (NaClO4) salt and Nano-filler titanium dioxide (TiO2) (i.e., (80 wt% PEO/20 wt% PVDF) + 7.5 wt% NaClO4 + x wt% TiO2 where x = 3, 6, 9, 12, 15, and 18) were prepared and characterized as potential candidates for battery applications. Electrochemical impedance spectroscopy (EIS) has been employed between the frequencies 10 Hz and 4 MHz to investigate electrical, dielectric and electric modulus properties of the prepared NCPE films. Effect of TiO2 Nano-filler concentration on the structural, ionic conductivity, and dielectric relaxation has been studied. The AC conductivity of the NCPE films at high frequencies obeys Jonscher’s power law. The values of DC ionic conductivity calculated by fitting the AC conductivity spectra to the best fit of Joncher’s power law are consistent with the values of DC ionic conductivity calculated from the bulk resistance (Rb) of the NCPE films. The ionic conductivity that depends on temperature follows the Arrhenius rule between the temperatures 298 and 328 K. The maximum ionic conductivity at ambient temperature 8.75 × 10–5 S/cm was obtained for (80 wt% PEO/20 wt% PVDF) + 7.5wt% NaClO4 + 15 wt% TiO2 NCPE film and it is attributed to the decrease in crystallinity. Using Wagner’s polarization technique ionic transport numbers of various NCPE films were measured.

Effect of surface modification of dispersoid on hybrid polymer electrolyte

This study reports the properties of hybrid polymer electrolyte films obtained via incorporating varying amounts of surface modified SiO2 nanoparticles and electrolyte solution (1 M LiBF4 in EMIMBF4) in PVdF-HFP. The SiO2 nanoparticles (diameter ~100–150 nm) have been synthesized by the conventional Stober's method and further modified chemically in two steps, viz., (i) carboxylation and (ii) EDC-NHS coupling. The surface modification of the nanoparticles has been confirmed by FTIR and XRD. The effect of addition of modified SiO2 and/or electrolyte solution has been studied using different characterization techniques. The positive impact of surface modification is evident by the reduced aggregation of the surface modified nanoparticles in the host matrix as compared to the unmodified ones (SEM micrographs). The effect of better dispersion of the modified nanoparticles in the polymer matrix has been reflected by the enhanced ionic conductivity (at room temperature) of modified SiO2 added electrolyte film (~2.94 mS/cm) compared to the films with no SiO2 and unmodified SiO2 (~1.90 mS/cm and ~1.56 mS/cm, respectively). The hybrid electrolyte film with maximum ionic conductivity has exhibited a wide electrochemical stability window (~5.5 V) and good mechanical and thermal stability (up to ~300 °C). The optimized hybrid film has been further used to fabricate an electric double layer capacitor (EDLC). The electrochemical performance of the cell has been studied using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) techniques.

Rational synthesis and characterization of IL-CNTs-PANI microporous polymer electrolyte film

A noble, safe and electrochemically stable microporous IL-CNTs-PANI polymer electrolyte has been reported. In the microporous polymer electrolyte (MPE), polyvinylidene fluoride (PVDF) was doped with an ionic liquid (IL), carbon nanotubes (CNTs) and polyaniline (PANI). The surface structure and element composition of MPE film were measured by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and fourier-transform infrared spectroscopy (FTIR). The thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) have carried out to characterize electrolytes’ thermal stability, and the electrochemical performance was measured by cyclic voltammetry (CV) and Tafel curves. It is found that a soft and porous MPE film can be obtained by changing the content of CNTs/PANI and the heat treatment temperature. Doping with different amounts of PANI has certain effects on the thermal stability and crystallization properties of MPE film. The prepared electrolyte membrane has good capacitance, wide electrochemical window (~3 V), certain charge transfer and ionic conductivity. Finally, the prepared electrolyte membrane was used to print a NO2 gas sensor, which proved that the MPE has the potential to become a gas-sensing material for NO2 sensors.

Structural, Vibrational, Electrical, Electrochemical and Capacitive Investigations on Ionic Liquid Doped P (VDF-HFP) + NaSCN Based Polymer Electrolytes

Background: Solid polymer electrolyte (SPEs) films based on poly (vinylidene fluoride-co-hexafluoropropylene) P(VDF–HFP) and sodium thiocyanate (NaSCN) are prepared using the solution casting technique. Methods: Ionic liquid (IL; 1-ethyl-3-methyl-imidazolium tricyanomethanide ([EMIM] [TCM]) is incorporated into the prepared polymer-salt complex matrix to enhance its ionic conductivity further. Polarized optical microscopy (POM) shows a change in the surface morphology of IL doped polymer electrolyte films. The composite nature of polymer electrolyte films is confirmed using Fourier transform infrared (FT-IR) spectroscopy via studying ion-ion and ion-polymer interactions. The structural morphology of ionic liquid doped polymer electrolyte films (ILDPE) confirms the complexation between the ionic liquid ([EMIM][TCM]), salt (NaSCN) and polymer P(VDF-HFP). This is further confirmed using DSC and XRD measurements. The XRD structural analysis confirms that the intensity of crystalline peaks present in IL doped solid polymer electrolyte films decreases as compared to that of the pure polymer as well as polymer salt complex system. XRD clearly indicates the enhancement in its amorphous nature, which is necessary to increase the conductivity. Results: The incorporation of IL into polymer salt-complex matrix leads to changes in the melting of polymer electrolytes, confirmed by DSC thermograms. Polymer electrolyte films are also characterized using impedance spectroscopy (IS) to check their electrical properties. The highest ionic conductivity is found to be 7.80×10-4 S cm-1 for 6 wt% IL doped polymer electrolyte film. Conclusion: The Linear sweep voltammetry (LSV) analysis shows that the optimized polymer gel electrolyte is electrochemically stable up to 1.5 V. The calculated value of ionic transference number (tion) is found to be 0.985. A laboratory scale electrical double layer capacitor (EDLC) has been fabricated using this highly conducting polymer electrolyte film. The specific capacitance value is found to be 1.31 F g-1.

Influence of NaF salt doping on electrical and optical properties of PVA/PVP polymer blend electrolyte films for battery application

Solid polymer electrolyte films of poly(vinyl alcohol) (PVA)/polyvinylpyrrolidone (PVP) doped with sodium fluoride (NaF) of different weight ratios (2, 4, 6, 8, and 10 wt%) have been prepared by using solution casting method. These films are characterized by XRD, FTIR, and SEM analysis. The X-ray diffraction (XRD) spectra show a characteristic PVA peak signifying its semi-crystalline nature. As NaF salt is incorporated into the polymer blend, the peak intensity decreases gradually, implying a decrease in the degree of crystallinity of the samples. The FTIR study confirmed the complexation, functional group occurred, and interaction between the different components in the polymer blend electrolyte, which suggests the micro-structural variations, takes place in polymer blended films by addition of NaF salt. The a.c. conductivity was measured at room temperature as well as in the temperature between the range 300 and 343 K. The conductivity was found to depend on NaF concentration which increases with increase in frequency and rise in temperature. The dielectric constant was found to decrease with increase in frequency and increased with temperature increase. The dielectric loss tangent peak was observed to increase in lower frequency range and its intensity is found to decrease with increasing frequency. Optical constants such as absorption coefficient (α), bandgap (Eg), extinction coefficient (k), refractive index (n), and real & imaginary part of optical dielectric constant were calculated. It was found that these optical constants found to depend on the concentration of NaF in PVA/PVP blend system. Transference number measurement (TNM) was carried out in order to investigate the nature of charge transport mechanism which showed that charge transport in the as-prepared polymer blend films is predominantly due to ions. Electrochemical cells were fabricated for the as-prepared samples and various cell parameters were determined.

Ammonium iodide salt-doped polyvinyl alcohol polymeric electrolyte for UV-shielding filters: synthesis, optical and dielectric characteristics

Polyvinyl alcohol (PVA) incorporated with various amounts of ammonium iodide salt (NH4I) composite polymer electrolyte films were prepared via the casting process. The XRD analysis, as a tool for structural investigation, confirms the polymer electrolytes formation. The transmittances of the studied samples are decreased with increasing NH4I fillers. The UV–Vis absorption spectra are shifted to the higher wavelengths, which indicate their importance for light shielding devices. The bandgaps decrease with the increase in NH4I content, attributed to the increase in the crystallite size. The calculated Urbach energy was found to increase with increasing NH4I salt fillers. The samples' optical limiting is carefully investigated using a He–Ne laser beam of wavelength = 632.8 nm. This result enhances light absorption behavior and makes the material suitable for optical UV-protection devices. The correlation between dielectric properties and conductivity is also understood and discussed. The dielectric permittivity e' of the samples is associated with the dipole, and polarization increased with the addition of NH4I salt content as the particle size increased according to XRD analysis. AC impedance spectroscopy was carried out to disclose the PVA doped with NH4I polymer electrolyte films as a function of various NH4I salt fillers. The analysis via complex electric modulus gives abnormal behavior by adding NH4I salt content, where the minimization of the electrode polarization can be achieved. Our results indicate that the newly designed composite polymeric electrolyte films are commonly appropriate for electronic and optoelectronic devices.

Preparation and characterization of titanium oxide based poly (vinylidene fluoride-co-hexafluoropropylene) polymer electrolyte films

The recent research focused on the fabrication of flexible battery and electrochemical performance in various fields such as flexible electronics, wearable sensors and implantable medical devices. Due to essential safety and less stability of the organic liquid-based electrolytes were replaced by the ionic liquid electrolytes with enhancing properties. In this manuscript, the flexible LIB was fabricated with the efficient, stable polymer matrix such as TiO2 doped PVDF-HFP polymer and high conductivity possessed EMIMDCA electrolytic liquid. The prepared TiO2 doped PVDF-HFP was analysed using various characterization techniques such as FTIR for the functional groups present in the polymer matrix, XRD for crystallinity of the TiO2 NPs, SEM for the determination of the pores before and after doping with TiO2 and TGA for the electrochemical stability. The electrochemical performance of fabricating battery was determined using cyclic voltammetry studies and results were suggested that high stability and ionic conductivity was observed in LIBs.

Effect of Al2O3 on electrical properties of polymer electrolyte for electrochemical device application

Polyvinylideneflouride (PVDF) based nanocomposite polymer electrolyte (NCPE) thin films consist of magnesium nitrate as ionic salt and aluminium oxide nanoparticles as nano-filler has been synthesized by solution casting technique. The electrical, structural, thermal, transport and discharge properties of synthesized films were characterized by Impedance Spectroscopy, X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, Differential Scanning Calorimetry-Thermal Gravimetric Analysis (DSC-TGA) and Wagner’s DC polarization technique respectively. Complexation was done in polymer electrolyte films were confirmed by XRD and FTIR studies. Composition dependant conductivity studies of films give highest conductivity value for composition: 70PVDF:30 Mg(NO3)2: 2Al2O3 i.e. σ ~ 1.01 × 10−4 S/cm. Thermal stability of polymer electrolyte was confirmed by DSC-TGA. Transport number (tion ~ 1) has been calculated from polarization technique. A test cell fabricated for OCC of NCPE in cell configuration Mg| NCPE| C cell and various parameters have been calculated.

Preparation, characterization and impedance spectroscopic studies of Na+ ion conducting PEO + PVDF-blended polymer electrolytes

The films of poly (ethylene oxide) (PEO) and poly (vinylidene fluoride) (PVDF)-based blended polymer electrolyte films complexed with sodium perchlorate (NaClO4) salt were prepared using the solution casting method. The complexation of NaClO4 salt with the blend of polymers PEO and PVDF was confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The melting temperatures were measured by differential scanning calorimetry (DSC). The surface morphology was examined by scanning electron microscopy (SEM). The prepared films were subjected to electrical impedance spectroscopy (EIS) to investigate ionic conductivity, dielectric and electrical modulus studies. It was observed that adding a small amount of PVDF to the PEO host polymer improves the interaction between the ions and the polymer and results in more ionic dissociation. Consequently, the number of active mobile carriers in the polymer matrix increases. The ionic conductivity studies have shown the maximum conductivity 2.84 × 10−6 S/cm at 303 K for the polymer blend 0.8PEO + 0.2PVDF complexed with 5 wt% NaClO4 and it is attributed to a decrease in crystallinity. Ionic transport numbers of various prepared samples were measured using Wagner’s polarization technique.

Conductivity and Dielectric Behavior Studies on Solid Polymer Electrolyte Based Poly(methyl methacrylate) (PMMA) Grafted Natural Rubber (MG49) Polymer Blends

A series of solid polymer electrolyte films, employing 49% poly(methyl methacrylate)(PMMA)-grafted natural rubber (MG49) as polymer host and lithium tertrafluoroborate (LiBF4) as conducting material were prepared by solution casting technique. The films of MG49-LiBF4, MG49-PMMA and MG49-Poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP) at the optimum weight percentage of LiBF4 (25 wt.%, 25 wt.% and 30 wt.%) respectively, were characterized using potentiostatic electrochemical impedance spectroscopy (EIS) technique to measure their impedans. The measurements were conducted at the temperature range from 303 K to 403 K. The values of dielectric constant, Ꜫr increases with the increase of ionic conductivity. The dielectric constant, Ꜫr and dielectric loss, Ꜫi decrease with increase in frequency at the low frequency region attributed to the electrode polarization effects, but almost negligible in the high frequency region due to frequency independent. The imaginary part, Mi of electrical modulus are observed increases with frequency. The systems are concluded as ionic conductors by the present of Mi peak in the plot Mi versus frequency. The presence of peaks at certain frequency in the tan δ versus frequency plots of the polymer electrolytes indicate the existence of relaxation of charge in all samples contributed by the ions and polar functional groups.