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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]

Recently, there has been significant interest in the development of high-performance electroactive ionic actuators that possess biocompatible, biodegradable, and bio-friendly characteristics for use in human-attachable electronics. However, research on biopolymer-based soft actuators has been relatively limited due to challenges such as the low ionic conductivity of biopolymers, difficulty in processing to achieve desired functionalities, and improper mechanical stiffness. Therefore, in this study, an electrospun silk membrane coated with sulfonated chitosan, in which membrane exhibits stable mechanical and electrochemical properties due to its interdigitated structures, is utilized to realize high-performance ionic biopolymer actuators. In particular, the introduction of sulfonated chitosan-ionic liquid on electrospun silk lowers the mechanical stiffness and increases the ionic conductivity, resulting in the provision of ion pathways through the interdigitated silk-chitosan domain. On bare electrospun silk membrane, the ionic electrospun silk-sulfonated chitosan actuators with graphene-PEDOT:PSS electrodes show a 165% increase in bending performance compared to those with only PEDOT:PSS electrodes. The developed biopolymer actuator, which shows substantial improvement in actuation performance, can be a promising candidate for use in skin-attachable and biomedical devices. [ABSTRACT FROM AUTHOR]

Polymeric single chloride-ion conductor networks based on acrylic imidazolium chloride ionic liquid monomers AACXImCYCl as reported previously are prepared. The chemical structure of the polymers is varied with respect to the acrylic substituents (alkyl spacer and alkyl substituent in the imidazolium ring). The networks are examined in detail with respect to the influence of the chemical structure on the resulting properties including thermal behavior, rheological behavior, swelling behavior, and ionic conductivity. The ionic conductivities increase (by two orders of magnitude from 10−6 to 10−4 S·cm−1 with increasing temperature), while the complex viscosities of the polymer networks decrease simultaneously. After swelling in water for 1 week the ionic conductivity reaches values of 10−2 S·cm−1. A clear influence of the spacer and the crosslinker content on the glass transition temperature was shown for the first time in these investigations. With increasing crosslinker content, the Tg values and the viscosities of the networks increase. With increasing spacer length, the Tg values decrease, but the viscosities increase with increasing temperature. The results reveal that the materials represent promising electrolytes for batteries, as proven by successful charging/discharging of a p(TEMPO-MA)/zinc battery over 350 cycles. [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]

The formulation of a hybrid gel polymer electrolyte (HGPE) system comprising of polymethyl methacrylate (PMMA) and polylactic acid (PLA) as a hybrid host polymer doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) has been successfully prepared in this study with the introduction of an ionic liquid, namely 1-Ethyl-3-methylimidazolium chloride (EMIMCl). Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were used to investigate the structural features of HGPEs. The FTIR analysis revealed that the complexation changes the peak intensity at region C = O stretching, CH2 bending, and C-O stretching. Meanwhile, XRD showed that the addition of EMIMCl altered the HGPE properties and formed an amorphous structure. The prepared HGPE sample was examined for ionic conduction properties through electrical impedance spectroscopy (EIS). It shows that by adding an EMIMCl to the PMMA-PLA-LiTFSI HGPE has decreased the activation energy (Ea) and increased the ionic conductivity. The sample containing 15 wt.% has the lowest Ea value of 0.057 eV and the highest ionic conductivity at room temperature of 3.20 10−3 S cm−1. The itemperature dependence was studied in the temperature range from 303 K to 393 K, the HGPE systems were found to follow Arrhenius behavior. The effect of EMIMCl content had decreased the viscosity of HGPEs which led to the gel-like type behavior. The potential windows stability analysis revealed that the highest conducting sample was electrochemically stable up to 3.3 V versus Li/Li+, thus showing that the present electrolytes are promising to be applied as in Li-ions battery. [ABSTRACT FROM AUTHOR]

In this article, the complexation of methylcellulose (MC) with tri-potassium phosphate (K3PO4) is investigated using an ultrasonication-assisted solution cast process. X-ray diffraction (XRD) analysis indicates that varying concentrations of K3PO4 salt (7–35 wt.%) disrupt the crystalline segment of the MC host matrix. The considerable shift in the intensity and orientation of the Fourier transforms infrared spectroscopy (FTIR) transmittance bands indicate the establishment of a charge-transfer entanglement between the polymer host and the dispersed salt. The optimum sample (28 wt.%) exhibits a high ionic conductivity of 1.74 × 10−5 S cm−1, potential stability of 3.48 V, and a cation transference number (ti) of 0.945. These findings show the relevance of the developed SPEs for possible application in electrochemical devices. [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]

Pristine and doped films of polyvinyl alcohol (PVA): poly (methacrylic acid-ethyl acrylate)(MAA-EA) (50:50) blend with various weight percentages (5, 10 and 15 wt%) of sodium chloride (NaCl) (Na+ ions) were prepared by a simple solution casting method. Exhibiting a decrease in diffraction peak intensities with increasing weight percentage of NaCl salt content, X-ray diffraction (XRD) indicated a decrease in crystallinity or less polymer blend. Thermogravimetric analysis (TGA) showed a decreasing trend in melting temperature of the doped films compared with the pure films. From the optical absorption and conductivity studies, among the prepared samples, the film with 15 wt% NaCl showed minimum absorption edge, direct band gap and indirect band gap values of 4.02, 4.52, 3.54 eV, respectively, and the maximum ionic conductivity of 9.85 × 10−8 S/cm. [ABSTRACT FROM AUTHOR]

Recently, considerable researches are conducted to develop promising polymer electrolytes for Li-ion batteries (LIBs). Herein, we prepared poly(lithium acrylate) (PAALi)-based composite polymer electrolytes (CPEs) containing alumina (Al2O3) nanoparticles. The addition of inorganic nanoparticles into the PAALi matrix can not only improve CPE's ionic conductivity ( σ D C ∼ 1.3 × 10 − 2 S / cm at 303 K), but also enhance CPE's mechanical properties due to the nanoparticles acting as cross-linkers between the PAALi chains. We systematically investigated the influences of inorganic nanoparticle types (pure alumina vs. vinyl functionalized alumina) and contents on ionic conduction and mechanical properties of PAALi-based CPEs. [ABSTRACT FROM AUTHOR]

As a prospective electrolyte for potassium-ion batteries, porous polymer electrolytic membranes were prepared based on poly (vinylidene difluoride-co-hexafluoropropylene) (PVDF-co-HFP) by a solution cast method. The casting solution, effects of the solvent, non-solvent and addition of nanoscale TiO2 particles were investigated in this study. The membranes were characterized by scanning electron microscopy (SEM) results in the surface morphology and porous nature of the fabricated membrane. X-ray diffraction (XRD) analysis gives the crystalline phase of the TiO2 doped membrane. The FTIR confirms the different functional groups present in PVDF-co-HFP films. Electrochemical stability of the prepared PVDF-co-HFP-TiO2 was performed by thermogravimetric analysis (TGA). The charge and discharge tests were conducted using the cyclic voltammetric analysis in this study. The addition of TiO2 particles to the polymer electrolyte was found to reduce the porousness of the PVDF-co-HFP membrane and to enhance the electrolyte uptake, ion conductivity and electrolyte/electrode interfacial stability of the membrane. [ABSTRACT FROM AUTHOR]

All-solid-state Li-ion batteries, have become increasingly important because of their highly reliable solid electrolyte materials. Flexible solid polyethylene oxide (PEO) based electrolytes have been widely studied. Nevertheless, this material exhibits low lithium-ion conductivity. Herein, we report the optimisation of the composition of PEO/polyvinylidene fluoride (PVDF)-based electrolytes to enhance ionic conductivity. When the weight ratio of lithium bis(trifluoromethane sulphonyl)imide and PEO/PVDF is 1:5 (LiTFSI:PEO/PVDF = 1:5), maximum conductivities are 2.98 × 10−5 S cm−1 at 30°C and 5.56 × 10−4 S cm−1 at 60°C. Furthermore, the all-solid-state battery using this solid electrolyte film, a Li metal anode, and a LiFePO4 cathode delivers initial discharge capacities of 149.6 mAhg−1 (0.1 C, 60°C) and 130.2 mAh g−1 (0.5 C, 60°C). Meanwhile, the solid-state lithium battery also presents good cycling performance and excellent rate capability at 60°C. [ABSTRACT FROM AUTHOR]

Recently, solid polymer electrolytes (SPEs) are of great current interest as substitutes to conventional liquid type electrolytes. Although the SPEs significantly alleviate the safety issues of the lithium-ion batteries based on conventional liquid electrolytes, they intrinsically exhibit low ion conductivity. In this study, a bicontinuous solid polymer electrolyte containing polyacrylonitrile (PAN) membrane and a mixture of succinonitrile (SN) and lithium bis(trifluoromethanesulfonyl)imide was prepared with different molarities of the lithium salt. Porous PAN membrane was fabricated via a thermally induced phase separation method (TIPS). The PAN-based SPE exhibited the maximum ionic conductivity of ∼5.0 × 10−3 S/cm at the salt molarity of 1.0 M. [ABSTRACT FROM AUTHOR]

The aim of this study is to prepare Er and Sm co-doped CeO2 electrolytes via the Pechini method and investigate the effects of simultaneous addition of Sm and Er on the structural and electrical features of CeO2. The structural, functional group analysis, microstructures, and electrical properties of the electrolyte samples are conducted by X–ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and impedance spectroscopy (IS). All the calcined and sintered electrolytes were obtained with cubic fluorite crystal structure without secondary oxide phases. After sintering at 1400 °C, highly dense electrolytes were achieved (> 90%). The IS measurements indicated that the highest ionic conductivity was observed for the singly doped Ce0.80Sm0.20O1.90 (σ750 °C = 3.86 x 10−2 S/cm) electrolyte. σ750°C was found to be 3.82 x 10−2, 1.73 x 10−2, 0.61 x 10−2 S/cm for Ce0.80Er0.05Sm0.15O1.90, Ce0.80Er0.10Sm0.10O1.90 and Ce0.90Er0.10O1.95, respectively. [ABSTRACT FROM AUTHOR]

A solid polymer blend electrolyte was prepared by using Polyvinyl alcohol (PVA) and Methacrylic Acid Ethyl acrylate (MAA: EA) polymers with different weight percentages (Wt%) of Potassium Chloride (KCl) by using solution casting technique, with water as a solvent. The structural, thermal, optical, and electrical properties of the prepared samples were studied. The X-ray diffraction pattern shows the decreasing trend in the degree of crystallinity due to the incorporation of KCl into the polymeric matrix. From the FTIR analysis, some peak intensities were decreasing and shifted in the case of KCl complexed films, which results in the complexation between the polymer blend and dopant ions. The TGA analysis reveals that the thermal stability of the KCl complexed films increases as dopant concentration increases. The SEM images reveal the structural reorganisation of polymer chains in the KCl complexed polymer blend electrolytes. UV-VIS spectra show that the optical constants such as absorption edge and band gap (both direct and indirect) values are decreased with an increase in KCl concentration. From conductivity data, it was noticed that the conductivity increased with the increase in the K+ ion concentration. The maximum ionic conductivity of 1.85 × 10−7 S/cm was obtained for the sample having 15 wt% of KCl salt. [ABSTRACT FROM AUTHOR]

Triblock copolymers comprising chemically complementary poly(ethylene oxide)/polyacrylamide (TBC) and their partially hydrolyzed derivative (TBChydr) were investigated as possible ion-conducting membranes for Li-ion batteries (LBs), dye-sensitized solar cells (DSSCs) and fuel cells (PEFCs). Two TBC samples consisting PEO blocks of variable block length (MnPEO = 6·104 and 3.5·104 kDa) were synthesized and used for these purpose. It was noticed that ionic conductivity of TBC membranes increases with PEO block lengthening from 6.2·10−11 to 3.2·10−9 S⋅cm−1. The introduction of additional ionic groups -COOH in polyacrylamide block of TBC has a positive effect on the conductive characteristics of copolymer membranes. The ionic conductivity of TBC membranes filled with LiPF6 increases with increasing of salt content. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This paper describes the results of solution casting technique derived PVP polymer electrolytes with different concentrations of Fe3+ ion as the dopant. Thermogravimetric curves of the pure and Fe3+ doped PVP polymer films show three distinct steps of weight loss. X-ray diffraction patterns indicate an enhanced amorphous nature of the polymer electrolyte with the increase in dopant concentration. SEM elucidates the surface morphology of the system. The optical band gaps of the films showed a decreasing trend with increasing dopant concentration. The FTIR spectra confirmed the complexation between the Fe3+ ions and the host polymer in terms of changes in intensity and certain bands position. The maximum ionic conductivity of 5.62 × 10−8 Scm−1 at 303 K has been observed for 5 mol% Fe3+ ions doped PVP sample. Hence, the observed properties of pure and Fe3+ ions doped PVP polymer electrolytes look very desirable and promising for battery applications. [ABSTRACT FROM AUTHOR]

New polymer electrolytes have been prepared from room temperature ionic liquid (IL) and poly(vinylidene fluoride)-hexafluoropropylene copolymer [PVdF-HFP]. The variation of thermal and electrical properties with varying polymer to IL concentration was investigated. The electrolytes had high thermal stabilities. The IL-PVdF-HFP electrolytes were freestanding, flexible films with room temperature conductivities of the order of 10−3 S cm−1. Increase in conductivity was found with increasing IL and also with increasing temperature. Increase in conductivity can be attributed to the fact that with increasing IL amorphicity increases as evident from XRD result. Dielectric studies showed decrease in relaxation time with increasing IL concentration indicating increase in polymer segmental motion which result in increase in conductivity. [ABSTRACT FROM AUTHOR]

The chemical cross-linking of epoxy resin has been known as an imperative way to improve the mechanical strength and thermal stability of solid polymer electrolytes (SPEs). Herein, we prepare flexible epoxy-based SPEs with high ion conductivity for electrochemical devices via ring-opening polymerization. A diglycidyl ether of bisphenol-A (DGEBA) epoxy resin was selected as the mechanical supporting SPE matrix. The high flexibility of SPEs can be obtained by adding poly(ethylene glycol) diglycidyl ether (PEGDE) plasticizer to the epoxy resin. Furthermore, the incorporation of electrolyte mixture of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salts and 1-butyl-3 methylimidazolium bis(trifluorosulfonyl)imide (BMIM-TFSI) ionic liquids allows for boosting ionic conductivity of the epoxy-based SPEs. Consequently, the high room temperature ionic conductivity ∼2.4 × 10−3 S/cm was achieved in the SPE containing 30 wt% of the epoxy and 70 wt% of the electrolyte mixture. [ABSTRACT FROM AUTHOR]

Recently, research on solid polymer electrolytes (SPEs) for lithium-ion batteries (LIBs) has been actively carried out as an alternative to conventional liquid electrolytes that present safety issues such as flammability and explosion. However, the SPEs show relatively low ion conductivity, compared to the liquid electrolytes. In this study, a poly(vinylidene difluoride) (PVDF)-based SPE was prepared by introducing two different electrolytes; one is weak-binding lithium bis(trifluoromethane)sulfonimide (LiTFSI) salt mixture with solvating plastic crystal succinonitrile (SN) and the other is lithium bis(fluorosulfonyl)imide (LiFSI) salts. Among the SPEs studied, the PVDF/LiFSI-containing SPE membrane exhibited the highest room temperature ion conductivity of 1 x 10−3 S/cm, characterized by electrochemical impedance spectroscopy (EIS). [ABSTRACT FROM AUTHOR]

Solution casting technique has been used to prepared chitosan-based polymer electrolyte films. The polymer electrolyte (PE) film containing 55 wt.% of biopolymer chitosan, 45 wt.% of NH4I salt and 80 wt.% of 1-butyl-3-methylimidazolium iodide (BMII) displayed the highest room temperature ionic conductivity of 3.02 × 10−4 S cm−1. The interaction between components in the biopolymer electrolyte has been optically investigated. The configuration of indium tin-oxide (ITO)/TiO2/Ru-complex (N3) dye/biopolymer electrolyte/Pt/ITO dye-sensitized solar cells (DSSCs) were fabricated. DSSC with chitosan-based PE consist of 80 wt.% BMII exhibited the highest efficiency of 1.2%. [ABSTRACT FROM AUTHOR]

Recently, extensive efforts have focused on the development of solid polymer electrolytes (SPEs) requiring high mechanical performance without sacrificing ion conductivity. To develop such a SPE, we incorporate robust silica mesoporous particles (SMP) into the epoxy-based SPEs, and increasing the SMP content raises the glass transition temperature of the SPEs. This enables to increase the mechanical properties of the SPEs, supported by the microstructural investigation showing a highly compact structure. Ionic conductivities of these SPEs follow Vogel temperature dependence, and increasing the silica nanoparticle content leads to a slight decrease in the conductivity, consistent with the dielectric response investigation. [ABSTRACT FROM AUTHOR]

Polymers based on ionic conducting materials have important interest because of their potential applications in polymer electrolytes and membranes for fuel cell application. PVdF-co-HFP poly(viniliden-co-hexafluoropropylene) was chosen as a polymer matrix because of its high ionic conductivity and better mechanical properties. Polymer matrix composites were prepared with various amounts of LiClO4 salt by a solution casting method. The sample-ionic conductivity measurements were recorded by AC impedance analyzer at different frequencies from 0.1 Hz to 20 MHz and at different temperatures from 273 to 373 K. The changes of nanoscopic free volume and free volume fraction in these materials were investigated in terms of temperature from 273 to 373 K using Positron Annihilation Lifetime Spectroscopy (PALS) and Simha-Somcynsky (SS) Hole Theory. The free volume had a bump at about 3% in weight percentage of the salt and there is a slight increase after 10%. The effects of weight percentages of LiClO4 and temperature were investigated. The mechanism of the ac ionic conductivity was presented in terms of the free volume models, however thermo-occupancy function justifies the best accurate representation of the data. [ABSTRACT FROM AUTHOR]

Composite gel polymer electrolytes (CGPE) were prepared using 1,3 Dioxolane (DIOX)/Tetraethyleneglycol dimethylether (TEGDME) as a combination of plasticizers, comprising with PEO, lithium salt (LiClO4) with the addition of filler SiO2. The composite gel polymer electrolytes were prepared by simple solution casting technique in an argon atmosphere. The electrolyte films were subjected to thermal, structural, morphological and electrochemical ac impedance analysis. A Lithium symmetric cell (Li/CGPE/Li) was fabricated and interfacial resistance as a function of time was studied. The film was thermally stable up to 298 °C. The ionic conductivity of high conducting sample is obtained in the order of 10−4 at ambient temperature. The transport properties of the gel polymer electrolyte were measured and the values are 0.6 which is sufficient for battery applications. The stability of the electrolyte film was analysed using the linear sweep voltammetry technique and the film was stable up to 3.4 V. [ABSTRACT FROM AUTHOR]

The present work deals with the development of carboxymethyl cellulose (CMC) blended with kappa carrageenan (KC) as a host-based polymer electrolyte (PE) system. The CMC/KC films were successfully prepared using solution casting method and were characterized through electrical impedance spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) methods, respectively. The FTIR spectrum revealed that the significant region of interaction transpires at wave number 1,057, 1,326, 1,584, and 3,387 cm−1 which correspond to the bending of C-O-C, bending of -OH, asymmetric of -COO− as well as the stretching of -OH, respectively. It has also been demonstrated that the complexation process occurred between CMC and KC. The CMC/KC blend PE system with a ratio of 80:20 achieved an optimum conductivity of 3.91 × 10−7 S cm−1 and had the lowest crystallinity percentage as suggested by the XRD analysis. [ABSTRACT FROM AUTHOR]

Poly(1-vinylpyrrolidone-co-vinyl acetate)-based quasi-solid polymer electrolytes doped with potassium iodide are prepared. The highest room temperature ionic conductivity of 1.72 mS cm−1is obtained. The dielectric studies are performed to understand the ion conduction mechanism. Fourier transform infrared study has been performed to understand complexation of the poly(1-vinylpyrrolidone-co-vinyl acetate)-based quasi-solid polymer electrolytes. The best power energy conversion efficiency (η) obtained is 2.94% with short circuit current density (Jsc) of 8.05 mA cm−2, open circuit voltage (Voc) of 0.58 V, and fill factor of 63% under standard light intensity of 100 mW cm−2irradiation. [ABSTRACT FROM PUBLISHER]

The doping of polymer electrolytes (PEs) with liquid crystal (LC) materials has been shown to improve the performance of dye-sensitised solar cells (DSSCs). This is achieved by promoting ionic conduction and increasing optical path length through multiple-light scattering within the photovoltaic devices. In LCs, it is well known that the length of the alkyl chain plays an important role since the LC morphology and mesophase stabilisation depend strongly on the alkyl group. In this work, liquid crystal-polymer composite electrolytes (LC-PEs) are prepared using nematic LCs with different alkyl chain lengths. The morphology of the LC-PEs is investigated and correlated with their electrical properties. Subsequently, DSSCs are prepared using the LC-PEs as a direct example of its application. It is shown that increasing the alkyl chain length of the LCs reduces the efficiency of the solar devices. The longer alkyl chains are speculated to intertwine, thus trapping the mobile ions and reducing the bulk ionic conductivity. For the same reason, longer alkyl chain LCs are thought to be unable to passivate the TiO2 surface through the adsorption of cyanobiphenyl groups and hence the higher probability of back recombination reaction between the electrons in TiO2 and PE. [ABSTRACT FROM AUTHOR]

DNA-DODA with 7 to 11 wt% of either LiClO4or LiI/I2ionic conducting membranes were synthesized, characterized, and applied in small TiO2-dye sensitized solar cells (DSSC). The best ionic conductivity values of 2.9 × 10−4and 2.3 × 10−5S/cm at 25°C were obtained for samples with 10 wt% of LiClO4and LiI/I2, respectively. The samples displayed Arrhenius behavior of ionic conductivity as a function of temperature and activation energies of 32.7 and 37.1 kJ/mol. TGA showed ∼10% weight loss up to 120°C and a start of degradation process at ∼200°C. The membranes with 10 wt% of LiClO4and 9 and 10 wt% of LiI/I2applied in DSSCs revealed solar efficiencies of 0.21, 0.37, and 0.51, respectively. [ABSTRACT FROM PUBLISHER]

In this work, the formulation of biopolymer electrolytes (BEs) system has been accomplished by incorporating various plasticizers with carboxymethyl cellulose–NH4Br through solution casting technique. The ionic conductivity at room temperature of BEs system was achieved at ∼10−4S cm−1with addition of 25 wt% NH4Br and enhanced to ∼10−3S cm−1when plasticizers were added. The temperature-dependence of the BEs system exhibits Arrhenius behavior. Jonschers power law was used to study the electrical properties and shows that the highest conducting BEs system can be represented by overlapping overlapping a large polaron tunneling model for poly(ethylene glycol) system a, small polaron hopping model for glycerol system, and a quantum mechanical tunneling model for ethylene carbonate system. [ABSTRACT FROM AUTHOR]

New polymer electrolytes (PEs), potentially interesting for solid-state electrochemical devices applications, were synthesized by a solvent casting method using pectin and ionic liquid (IL)N,N,N-trimethyl-N-(2-hydroxyethyl)ammonium bis(trifluoromethylsulfonyl)imide ([N1 1 1 2(OH)] [NTf2]. The resulting electrolytes besides being moderately homogenous and thermally stable below 155°C, they also exhibited good mechanical properties. The SPE membranes were analyzed by differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and complex impedance spectroscopy. [ABSTRACT FROM PUBLISHER]

A solid polymer electrolyte based on lithium hydroxide (LiOH) added with polyethylene glycol and polyvinyl alcohol polymers was synthesized by solution casting. The structural variation with respect to loading wt% of LiOH reveals the semicrystalline property of polymer electrolyte. The differential scanning calorimetry data shows the onset of crystalline to amorphous transition, which occurs nearly to the melting peak, for higher salt content. The structural properties and cross-linking between polymer and salt were demonstrated by polarized optical microscopy. The polymer electrolytes were subjected to AC impedance analysis spectra for obtaining the ionic conductivity at different temperature. The charge carriers relax much faster for higher lithium salt concentration based polymer electrolyte and produces higher conductivity. The highest room temperature conductivity 2.63 × 10−5S/cm is obtained for 8 wt% loading of lithium salt based polymer electrolyte, confirming their use in preparation of ion conducting devices. [ABSTRACT FROM AUTHOR]

In this work, the influence of 2-mercaptobenzimidazole (2-MCBI) on poly(vinylidinefluoride-co-hexafluoropropylene)/KI/I2(PVDF-HFP/KI/I2) polymer electrolytes were studied. The pure and different weight percentage ratios (20, 30, 40 and 50%) of 2-MCBI doped PVDF-HFP/KI/I2electrolytes were prepared by a solution casting technique. The as-prepared polymer electrolyte films were characterized using various techniques such as Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), X-ray diffractometer (XRD), alternating current (AC)-impedance analysis. The addition of 2-MCBI with pure PVDF-HFP/KI/I2was found to increase the ionic conductivity of electrolyte. Among the various additions, 30 wt% 2-MCBI doped PVDF-HFP/KI/I2showed the highest room temperature ionic conductivity values than the others. The dye-sensitized solar cell (DSSC) fabricated using this optimized polymer electrolyte achieved a high power conversion efficiency of 4.40% than the pure PVDF-HFP/KI/I2(1.74%) at similar experimental conditions. Thus, the 2-MCBI doped polymer electrolyte has proven to be an effective substitute to the liquid electrolyte in DSSCs. [ABSTRACT FROM AUTHOR]

Polymer electrolyte membranes (PEMs) play a crucial role for use in major polymer-based fuel cell applications. Key PEM properties such as ion conductivity, reactant permeability, and chemical/physical stability are strongly influenced by the chemical structure and processing conditions of PEMs. This paper presents the property measurement techniques of PEMs using stand-alone membranes and membrane electrode assembly (MEA) configurations. PEM properties such as ion exchange capacity, water uptake, ion conductivity, gas/liquid permeability, and chemical/physical stability are discussed with emphasis on measurement techniques. In addition, the measurement techniques for polymer electrolyte in the catalyst layer are briefly discussed. This review may give some insight to polymer scientists when novel PEM materials are designed, prepared, screened, or fine-tuned for advanced fuel cell systems. [ABSTRACT FROM AUTHOR]

Two new series of solid polymer electrolytes (SPEs) based on phosphorus containing (co)polyesters (PPE) and Lithium triflate were obtained. PPEs are composed of phosphonate moeties (cyclohexyldichlorophosphonate (CHDP)) as linking agent and two diols: PEG (6000) and poly(tetramethylene glycol) (PTMG) inPPE I, and PEG (6000) and 4,4′-cyclohexylidenebisphenol (bisphenol Z, BZ) inPPE II. Polycondensation was carried out in solution in the presence of triethylamine (TEA) as scavenger of HCl side product (PPE I–IIa) and in the absence of any acid acceptor (PPE I–IIb). The Limiting Oxygen Index (LOI) and thermal analysis were performed both on polymers and membranes. The ionic conductivity of SPE membranes based onPPE-salt complexes, with various salt concentrations, was investigated at different temperature and ionic transference numbers were determined. Optimum composition was obtained for the polymer which contains in structure only alkyl units and 15% Lithium triflate. [ABSTRACT FROM PUBLISHER]