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Solid polymer electrolyte blends with varied compositions of poly(ethylene oxide) (PEO)/carboxymethyl cellulose (Na-CMC) in 10/90, 50/50, and 90/10 compositions have been successfully prepared by means of the solution cast technique at room temperature. The modification of the structural, optical, and electrical properties of the prepared blend samples was studied by employing XRD, FTIR, UV-Vis, and electrical impedance spectroscopy methods. X-ray diffraction studies revealed that the crystalline nature gradually transforms into amorphous as the Na-CMC content increases in the sample. The variation of bands noticed in the Fourier transform infrared spectroscope characteristic spectrum of the blends reveals the formation of complexes between the individual polymers. The analysis of optical properties using a UV-Vis spectrometer in the wavelength range of 900–1100nm, shows a gradual decrease in the optical indirect energy band gap with an increase in Na-CMC content in the blend. The study of the electrical properties of the blend carried out in the frequency range 50 Hz–1MHz and temperature range 303K–338K, using an electrical impedance analyzer reveals that, the dielectric constant and loss decrease with the rise in frequency, exhibiting the usual behavior of the polymers. AC conductivity is found to increase with an increase in temperature. The highest value of ionic conductivity is found to be 6.06 × 10−3Scm−1 for the blend with a 10/90 composition. [ABSTRACT FROM AUTHOR]

Solid polymer electrolytes (SPEs) have been recognized as a preferable alternative to liquid electrolytes for energy storage application. However, low conductivity of SPEs has restricted their application. This issue can be overcome by adding controlled amount of dopant salt to the SPEs. In this work, various concentration of ammonium thiocyanate (NH4SCN) salt was incorporated into dextran using solution cast technique in order to study the effect of NH4SCN on electrical properties, crystallite size, morphology and ionic conductivity. Results from Fourier-transform infrared (FTIR) analysis confirm the coordination of cation of salt at the OH and C-O-C groups of dextran. Deconvolution of the FTIR band between 2015 and 2090 cm−1 was performed to investigate the ion association and dissociation phenomena. It is confirmed that the ion mobility and diffusion are directly proportional to the ionic conductivity. Based on the electrochemical impedance spectroscopy (EIS) result, an optimum ionic conductivity of (3.18 ± 1.19) × 10−4 S cm−1 was achieved with the sample containing 40 wt.% salt concentration. The conductivity result can be clarified by the crystallite size obtained from X-ray diffraction (XRD) analysis and field emission scanning electron microscopy (FESEM) images. [ABSTRACT FROM AUTHOR]

Solid polymer electrolytes were prepared using polymethyl methacrylate (PMMA), ethylene carbonate (EC), lithium trifluoroethane-sulfonate (LiTf), magnesium trifluoro-methanesulfonate (MgTf2). The ionic conductivity was measured at 30 °C as 6.17 × 10−6 and 1.83 × 10−4 S cm−1, respectively. The ionic mobility (μ), charge carrier diffusion coefficient (D) and the ion number density (n) of the samples have been calculated to understand the effect of these parameters on the ionic conductivity. The experimentally obtained values of Z r and Z i are compared with theoretical calculations. The PMMA-EC-MgTf2 sample exhibits higher dielectric constant compared to PMMA-EC-LiTf. The MgTf2 containing sample also exhibits a higher transference number. [ABSTRACT FROM AUTHOR]

Poly(acrylamide-co-acrylic acid) (PAAm-PAA) based solid polymer electrolytes (SPEs) containing potassium iodide (KI) have been prepared. The complexation between PAAm-PAA and KI has been identified through the position changes at the asymmetric NH2 stretching and CH2 stretching; and the intensities changes at the amide (C = O, C-N) and carboxylate (COO-) bands using Fourier transform infrared (FTIR) spectroscopy. PAAm-PAA film exhibits a room temperature (RT) ionic conductivity of (8.8 ± 0.8) × 10−11 S·cm−1 which increases to maximum at (4.0 ± 0.5) × 10−7 S·cm−1 with 45 wt.% KI addition. The conductivity-temperature dependence studies of all samples followed the Arrhenius rule. [ABSTRACT FROM AUTHOR]

Understanding the transport mechanism of Li+ in solid polymer electrolytes is beneficial for improving the safety and energy density of lithium-ion batteries. In this work, we investigate the effects of chain length of poly (ethylene oxide) (PEO) and anions (TfO-, TFSI-, PFSI-) on ion transport properties in PEO-lithium salt systems using all-atom molecular dynamics simulations. We found that the Li+ and PEO monomers are co-diffusion, regardless of the PEO chain length and the type of anion. The diffusion of Li+ becomes slower with PEO chain length and reaches an asymptotic value. In addition, the motion of the Li+ is the slowest in PEO/LiTfO systems. We conclude that the free volume of the systems plays a decisive role in the transport properties of Li+. [ABSTRACT FROM AUTHOR]

Poly(ethylene oxide) has been intercalated inside the interlayer galleries of montmorillonite clay and the electrochemical properties of the nanocomposite have been investigated. Interlayer spacing and clay gallery width increase with increasing MMT concentration confirming intercalation of PEO into MMT as observed from XRD results. The fraction of free anions as calculated from FTIR, increases with increasing clay content and remains constant beyond 7.5 wt. % of clay content. Ionic conductivity of the order of 10−4 Scm−1 has been obtained in the case of MMT based electrolytes. The initial increase of conductivity with increasing MMT content can be attributed to the increase fraction of free ions which eventually increases ionic conductivity. After 7.5 wt. % of MMT loading ionic conductivity decreases due to the high viscosity of MMT. Interfacial stability results show that passivation takes place very slowly in MMT based electrolytes. Dielectric properties show that at high frequency relaxation takes place due to the segmental motion of polymer chains and it proves the hopping of ions. [ABSTRACT FROM AUTHOR]