Ion Conducting Polymer Electrolyte Films Research Articles

The D.C electrical properties of Lithium ion conducting solid polymer electrolyte based on polyvinyl alcohol

Lithium ion conducting polymer electrolyte films based on polyvinyl alcohol (PVA) with different concentration of lithium perchlorate salt, using a solution cast technique, have been prepared. The Solid polymer electrolyte (SPE) hasbeen characterized by XRD technique. The XRD analysis reveals the amorphous nature of the polymer electrolyte. Polymer sample of PVA with different concentration of lithium salt (0, 5, 10, 20) wt% with double distilled water as solvent have been prepared and studied. High conductivity of 1.85771X10-07 has been observed for the PVA with 20% LiClO4. The temperature dependent conductivity of polymer electrolyte follows the Arrhenius relationship which shows hopping of ion in the polymer system. The experiment result showed that the D.C electrical conductivity increased with increasing the lithium salt concentration.

Investigation on the Electrical Properties of Lithium Ion Conducting Polymer Electrolyte Films Based on Biodegradable Polymer Blends

In the present work, the polyvinyl alcohol/poly (N-vinyl pyrrolidone)/Lithium carbonate (PVA/PVP/Li2CO3) blend polymer electrolyte films were prepared via the solution casting technique, with varying concentration of Li2CO3 salt (0 to 25 wt%). The surface morphology of these blend electrolyte films was examined using polarized optical microscopy (POM). The electrical properties such as impedance (Z), quality factor (Q-factor) and phase angle () of PVA/PVP/Li2CO3 blend electrolyte films were elucidated using impedance analyzer in the frequencies from 50 Hz to 20 MHz and temperatures from 30 °C to 150 °C. It was observed that the inclusion of Li2CO3 salt into the PVA/PVP blend matrix led to an increase in the Z,  and Q-factor values. The maximum Z of 1.19 x 107 Ω (50 Hz, 30 °C) was observed for blend electrolyte film containing 25 wt% Li2CO3 salt. The  also increased from 139° (20 MHz, 90 °C) for PVA/PVP blend to 179° (20 MHz, 40 °C) for blend electrolyte film containing 25 wt% Li2CO3 salt. The Q-factor values was increased from 27.4 (10 MHz, 140 °C) for PVA/PVP blend to 56.2 (5 MHz,salt, 80 °C) for blend electrolyte film containing 25 wt% Li2CO3 salt.

Physical investigations on pure and KBr doped poly(vinyl alcohol) (PVA) polymer electrolyte films for solid state battery applications

Potassium ion conducting polymer electrolyte films were prepared based on poly(vinyl alcohol) (PVA) complexed with 5, 10 and 15 wt% potassium bromide (KBr) salt using solution-casting technique. X-ray diffraction and Fourier transform infrared spectroscopy studies were used to determine the complexation of the KBr salt with polymer structure. Differential scanning calorimetry was used to determine the melting temperatures and relative crystallinity values of pure PVA and PVA:KBr complexed films. The conductivity of the polymer films was measured using impedance spectroscopy. Room temperature ionic conductivity was found to be a maximum (1.23 × 10−5 S cm−1) for the (PVA:KBr) (85:15) complexed film, whose K+ ion transport number was found to be 0.97. Electrochemical cells were fabricated in the configuration K/(PVA:KBr)/(I2 + C + Electrolyte) and their discharge characteristics were studied under a constant load of 100 kΩ.

Thermal Analysis of 1-Ethyl-3-Methylimidazolium Trifluoromethanesulfonate Ionic Liquid to PEO-NaCF<sub>3</sub>SO<sub>3 </sub>Polymer Electrolyte

The objective of this study is to investigate the effect of ionic liquid to PEO-NaCF3SO3 solid polymer electrolyte. Sodium ion conducting polymer electrolyte films consisting of Polyethylene oxide (PEO) as a polymer host, Sodium trifluoromethanesulfonate (NaCF3SO3) as doping salt and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMiTF) as ionic liquid has been prepared by solution cast technique. Different amounts (5, 10, 15, 20, 25 and 30 wt. %) of EMiTF will be added to the optimized polymer-salt composition to develop PEO - NaCF3SO3 – EMiTF polymer electrolyte. Difference Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) indicated that the crystalline degree and the weight loss % of the electrolyte decrease with increasing the wt. % of the EMiTF respectively. The ionic transference number was found in the value of 0.95 which suggests that ions are the charge carriers.

Structural and Dielectric Properties of PVP Based Composite Polymer Electrolyte Thin Films

The study and application of thin film technology is entirely entered in to almost all the branches of science and technology. Transparent conducting oxide films have been widely used in the fields of flat panel displays, solar cells, touch panels and other optoelectronic devices owing to their high electrical conductivity and optical transmittance in visible region. In the present study, Solid state ion conducting polymer electrolyte films were prepared by doping nano-sized TiO2 particles on PVP (poly vinyl pyrrolidone) complexed with MgSO4·7H2O salt by solution casting technique and characterized by powder XRD, DSC, SEM, optical and dielectric studies. The XRD pattern of the prepared sample shows the semi-crystalline nature. SEM and EDS confirms the presence of compounds inside the material. Optical absorption studies are used to measure the bandgap of the prepared sample. Dielectric studies are performed to observe the conductivity of the sample.

A study of structural, electrical and electrochemical properties of PVdF-HFP gel polymer electrolyte films for magnesium ion battery applications

New magnesium ion conducting polymer electrolyte films are developed and their experimental investigations are reported. The polymer electrolyte films are composed of various poly(vinylidene fluoride-co-hexafluoropropylene):magnesium trifluoromethanesulfonate compositions (PVdF-HFP:Mg(Tf)2 in weight ratio) with different quantities of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid (EMITf). X-ray diffraction reveals that the pristine PVdF-HFP polymer film possesses a semi-crystalline structure and its amorphicity increases with increasing Mg(Tf)2 and EMITf concentrations. From thermal analysis, the melting temperature (Tm), relative crystallinity (χc) and thermal stability of the 90PVdF-HFP:10Mg(Tf)2 gel polymer electrolyte film doped with 40wt.% EMITf are obtained as 112°C, 21.8% and 355°C, respectively. The room-temperature ionic conductivity of the gel polymer electrolyte film increases with increasing EMITf concentration and reaches a high value of approximately 4.63×10−3Scm−1 at 40wt.% EMITf due to its amorphicity increase and interconnected pore structure. For the 40wt.% EMITf electrolyte film, the temperature dependence of ionic conductivity follows the Arrhenius relation with an activation energy of 0.35eV. The electrochemical stability window of the 40wt.% EMITf electrolyte film is determined as ∼4.8V. The findings from this study are promising and have great potential for practical ionic device applications, particularly in rechargeable magnesium ion batteries.

Electrical properties of biodegradable poly(ɛ-caprolactone): lithium thiocyanate complexed polymer electrolyte films

Lithium ion conducting polymer electrolyte films based on biodegradable poly(ɛ-caprolactone) (PCL) complexed with lithium thiocyanate (LiSCN) salt were prepared by solution cast technique. Thermal and electrical properties of the polymer electrolyte films were studied using differential scanning calorimetry (DSC) and ac impedance spectroscopy. In order to investigate the ion conduction mechanism and relaxation behavior of complex polymer electrolyte films, the conductivity, dielectric constant, loss tangent and electric modulus were analyzed as a function of frequency and temperature. The variation of conductivity with frequency obeyed the Johnscher's power law. The dielectric constant exhibited a higher value at a lower frequency and increased with rising temperature due to the polar nature of host polymer. The activation energies for both dc conductivity and relaxation had the same value (∼0.87 eV), implying that the charge carriers responsible for both conduction and relaxation were the same.

Lithium Ion Conducting Polymer Electrolyte Based on Poly (Vinyl Alcohol) – Poly (Vinyl Pyrrolidone) Blend with LiClO4

Li+ ion conducting polymer electrolyte films have been prepared based on Poly (Vinyl alcohol) - Poly (Vinyl pyrrolidone) blend with LiClO4 using a solution casting technique. The increase in the amorphous nature of the polymer electrolytes has been confirmed by XRD analysis. The complex formation between the polymer and the salt has been confirmed by FTIR analysis. The highest ionic conductivity has been found to be 8.64 × 10−6 Scm−1 at ambient temperature for 0.22 molecular weight percentage of LiClO4 doped Poly (Vinyl alcohol) - Poly (Vinyl pyrrolidone) blend with low activation energy (0.59 eV). The dielectric behavior has been analyzed using dielectric permittivity (ϵ′) of the samples.

Preparation and characterization of PVP-based polymer electrolytes for solid-state battery applications

Sodium ion conducting polymer electrolyte films based on poly(vinyl pyrrolidone) (PVP) were prepared using solution casting technique. Structural characterization was performed using X-ray diffraction (XRD) technique. Increase in amorphous phase with the increase of dopant concentration was observed. Temperature dependence of electrical conductivity was performed using AC impedance analyzing technique in the frequency range of 0.1 KHz to 1 MHz. Activation energy values were evaluated, as well. Optical absorption studies were carried out in the wavelength range 200–600 nm. Absorption edge, direct band gap, and indirect band gap values were also evaluated. Optical absorption edge and optical band gap (both direct and indirect) showed decreasing trend with increasing the concentration of the dopant. Dominant conducting species in the present electrolyte system was determined using Wagner polarization technique and dominant conducting species were found to be ions rather than electrons. Solid-state batteries were developed using the present solid polymer electrolyte system and discharge characteristics over the load of 100 kΩ. Cell parameters, e.g., open circuit voltage, short circuit current, current density, power density were evaluated, too. Among these cells, the cell made up of PVP/NaI (70/30) ratio for electrolyte was found to be more stable than the other two cells PVP/NaI (90/10) and (80/20) ratios and the obtained results were comparable with the results achieved by other studies.

Electrical properties of poly(vinyl alcohol) (PVA) based on LiFePO4 complex polymer electrolyte films

Li ion conducting polymer electrolyte films were prepared based on poly(vinyl alcohol) (PVA) with 5, 10, 15, 20, 25 and 30 wt% lithium iron phosphate (LiFePO4) salt using a solution-casting technique. X-ray diffraction (XRD) was used to determine the complexation of the polymer with LiFePO4 salt. Differential scanning (DSC) calorimetry was used to determine the melting temperatures of the pure PVA and complexed films. The maximum ionic conductivity was found to be 1.18 × 10−5 S cm−1 for (PVA:LiFePO4) (75:25) film, which increased to 3.12 × 10−5 S cm−1 upon the addition of propylene carbonate (PC) plasticizer at ambient temperature. The Li+ ion transport number was found to be 0.40 for (PVA: LiFePO4) (75:25) film using AC impedance and DC polarization methods. Dielectric studies were performed for these polymer electrolyte films in the frequency range of 10 Hz to 10 MHz at different temperatures. The activation energies of the complexed films were calculated from the dielectric loss tangent spectra and were found to be 0.35, 0.30, 0.27 and 0.28 eV. The cyclic voltammogram (CV) curves of (PVA: LiFePO4) (75:25)+PC film exhibited higher specific capacities than those for other films.

Electrical and optical properties of pure and KClO3-doped P(MMA-CO-4VPNO) polymer electrolyte films

Ion-conducting polymer electrolyte films based on a copolymer poly(methyl-methacrylate-co-4-vinyl pyridine N-oxide) [P(MMA-CO-4VPNO)] complexed with potassium chlorate (KClO3) were prepared by solution cast technique. The complexation of KClO3 salt with the polymer was confirmed by X-ray diffraction and infrared studies. The electrical conductivity and optical absorption of pure and KClO3-doped P(MMA-CO-4VPNO) polymer electrolyte films have been studied. The electrical conductivity increased with increasing dopant concentration, which is attributed to the formation of charge transfer complexes. The variation of electrical conductivity with temperature shows two regions with two activation energies. Optical properties like direct band gap, indirect band gap, and optical absorption edge were investigated for pure and doped polymer films in the wavelength range 300–550 nm. It was found that the energy gaps and band edge values shifted to lower energies on doping. The behavior is in an agreement with the activation energies obtained from the conductivity data.

Polymer electrolyte system based on (PEO+KBrO 3) — its application as an electrochemical cell

Ion-conducting polymer electrolyte films based on poly (ethylene oxide) (PEO) complexed with potassium bromate (KBrO 3) are prepared by a solution-cast technique. Several experimental techniques such as differential scanning calorimetry (DSC), dc-conductivity and transference number measurements are employed to characterise this polymer electrolyte system. The conductivity–temperature plots show two regions in the temperature range of study and transport number data which indicate that the charge transport in this electrolyte system is predominantly due to ions. Using these polymer electrolyte films, solid-state electrochemical cells are fabricated and their discharge characteristics are examined for a constant load of 100 kΩ. Several cell parameters associated with the cells are evaluated and reported.

Ion conducting polymer electrolyte films based on (PEO+KNO 3) system and its application as an electrochemical cell

Ion conducting polymer electrolyte films based on poly (ethylene oxide) (PEO) complexed with potassium nitrate (KNO 3) have been prepared by solution-cast technique. The complexation of KNO 3 salt with the polymer PEO has been confirmed by X-ray diffraction (XRD) and Infrared (IR) studies. DC conductivity in the temperature range 303–373 K and transference number measurements have been employed to investigate the charge transport in this polymer electrolyte system. Transport number data have shown that the charge transport in this polymer electrolyte system is predominantly due to ions. Using this polymer electrolyte, solid state electrochemical cells have been fabricated. Various cell parameters associated with these cells are evaluated and reported.

Conductivity and parametric studies of a (PEO+(glass)(15Na2O–15NaF–70B2O3)) cell

Ion conducting polymer electrolyte films based on poly(ethylene oxide) (PEO) complexed with a glass (15Na 2 O–15NaF–70B 2 O 3 ) are prepared by a solution—cast technique. The complexation of the glass with PEO is confirmed by X-ray diffraction analysis. DC conductivity in the temperature range 303–373 K and transference number measurements are performed in order to investigate the charge transport in the polymer electrolyte system. The conductivity of the (PEO+glass) electrolyte is about 10 4 times larger than that of pure PEO at room temperature. The transference number data show that the charge transport in this polymer electrolyte system is predominantly due to ions. Using these polymer electrolytes, solid-state electrochemical cells are fabricated. Various parameters associated with these cells are evaluated and compared with those of other reported cells.

Ion transport studies in PEO∶NH4I polymer electrolytes with dispersed Al2O3

Ion conducting polymer electrolyte films having high salt concentrations have been studied. The system studied is PEO∶NH4I, dispersed with α-Al2O3. Mechanically stable films with NH 4 + /EO ratio ≥0.13 have been obtained by dispersal of Al2O3. The films have been characterized using various techniques such as X-ray diffraction (XRD), differential thermal analysis (DTA), polarization and complex impedance spectroscopy. Intercorrelation between polymer matrix crystallite size, conductivity, and α-Al2O3 particle size is established.

Experimental observation of large-size fractals in ion-conducting polymer electrolyte films.

We have succeeded in growing large-size fractals (\ensuremath{\sim}2--3 cm) in solution-casted ion-conducting polymer films of polyethylene oxide doped with ammonium iodide. These are shown to be ``diffusion-limited aggregates'' due to iodine ions in random walk. This mechanism is supported by energy dispersive x-ray analysis, x-ray diffraction, optical absorption, polarization, and complex impedance studies.