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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]

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]

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]

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]

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]

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]

A series of PVA/CMC polymer composite films with different amounts of NiCuZnFe2O4(nickel–copper–zinc–ferrite) was prepared by means of solution-casting technique. These films were characterised using various techniques like X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–visible) and AC electrical conductivity measurements. Recorded XRD pattern at room temperature shows an increase in amorphousity of the matrix with concentration of NiCuZnFe2O4nanoferrite. Microstructural parameters were computed using an in-house program employing XRD data. UV–visible spectra show that the optical absorption of the PVA/CMC nanocomposite films in the UV region is quite high. FTIR spectra show the stretching of the major vibration bands associated with organic–inorganic chemical groups present in the nanoferrite-doped polymer blends. Measured AC electrical conductivity of prepared samples shows that the added nanoferrite does increase the ionic conductivity at lower concentrations. [ABSTRACT FROM AUTHOR]

Symmetrical electrical double layer capacitors with ionic liquid potassium hydroxide (KOH)-based poly(acrylic acid) gel polymer electrolytes and activated charcoal electrodes were constructed and characterised. The optimised composition of gel polymer electrolytes exhibits high room temperature ionic conductivity of 0.46 S cm−1 with good mechanical and dimensional stability, which is suitable for their application as electrolyte in electrical double layer capacitors. Analysis shows that the maximum value of capacitance was 0.343 F cm−2, and this value corresponds to an energy density equal to 0.111 J cm−2. Electrical double layer capacitor exhibits large capacitance and high energy density. The results indicate that the gel polymer electrolyte used in our study is promising and is suitable as a solid electrolyte for high-performance all-solid-state electrochemical devices. [ABSTRACT FROM AUTHOR]

A room temperature ionic liquid 1-allyl-3-methyl-imidazolium bicarbonate ([amim][HCO3]) has been successfully synthesized. The molecular structure is determined by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. The viscosities and ionic conductivities of the resultant [amim][HCO3] are measured in the temperature range from 273.15 to 343.15 K, showing that the ionic conductivity increases with increasing of solvent concentration and temperature. However, the viscosity of the ionic liquid is inversely proportional to temperature. The resultant [amim][HCO3] exhibits reasonable ionic conductivity, easy preparation and low cost, making it a good candidate in modern electrical devices. [ABSTRACT FROM AUTHOR]

Nanocomposites of Yb2O3stabilized ZrO2(YbSZ) containing fine Al2O3dispersions were fabricated by conventional powder mixing and a pressureless sintering technique. A fine homogeneous microstructure was obtained for the composites. This microstructural refinement decreased the size of defects in the composites, which significantly increased the fracture strength of the composites compared to that of monolithic ZrO2. The composites had the same ionic conductivity values as those of the monolithic ceramics at high temperatures (in the range of 800–1000 °C). Furthermore, the activation energy at high temperatures was independent of the Al2O3content, whereas in the lower temperature regime (300–800 °C), it varied with the Al2O3fraction. This indicated that different O2-conduction-based activation processes were operating in the two temperature regimes. The O2-ion transfer could easily occur at high temperatures due to the presence of the Al2O3particulate dispersion in the composite system. From these results, it was concluded that the dispersion of fine grained Al2O3into YbSZ is advantageous for achieving high-strength ion-conductive cubic zirconia. [ABSTRACT FROM AUTHOR]

Polyimide-arylsilaneimide quasi nanocomposites have been prepared by an innovative route. Various structural features have been evaluated and verified by FTIR and XP S techniques. A dynamic mechanical analysis and tensile test have been performed on these quasi nanocomposites and properties have been found to be far better than those of the neat polyimide. Enhancement in the properties of these quasi nanocomposites has been attributed to the availability of high surface area to volume ratio for bonding of the nanoparticles crabbed in the continuous matrix and the same has been verified by atomic force microscopy. A hypothetical phase diagram has been proposed and different transformations occurring during the formation of quasi nanocomposites discussed. Wide angle X-ray has indicated the increment in crystallanity in quasi nanocomposites and the same has been found to be responsible for the enhancement in ionic conduction. Dielectric relaxations occurring in quasi nanocomposites have been correlated with the structural features. [ABSTRACT FROM AUTHOR]

The system Li2O-TiO2-P2O5 is prepared in order to investigate the effect of heat and mechanical treatment on the conductivity. Mechanical milling (MM) method was used to prepare the system. The effects of sintering temperature and mechanical milling treatment on the system Li2O-TiO2-P2O5 have been investigated using electrochemical impedance spectroscopy, X-ray differential analysis and laser particle sizer. Some crystalline phases with slight amorphous nature were detected in the highest conducting sample. The samples were sintered at several temperatures from 300 to 1000°C. The sample treated at 800°C obtained the smallest particle size of about 300 nm. The sample treated at 800°C and milled for 4 h obtained the highest conductivity with a value of 8·89 × 10-5 S cm-1. The activation energy was found to be as low as 0·075 eV. [ABSTRACT FROM AUTHOR]

The insolubility of chitosan in a wide range of organic solvents has limited the application of chitosan especially in electrochemical systems. In order to improve its solubility, acyl modification of chitosan was carried out in the present study. Films of hexanoyl chitosan-based polymer electrolyte were prepared by solution casting technique. The effect of filler on the transport properties of hexanoyl chitosan-LiCF3SO3-ethylene carbonate electrolytes has been investigated. The conductivity for fillerfree polymer electrolyte is 2·75 × 10-5 S cm-1. The addition of 6 wt-%Al2O3 increased the conductivity by one order of magnitude to 1·01 × 10-4 S cm-1. Within the temperature range investigated, the conductivity of the polymer electrolytes are thermally assisted and can be described by Arrhenius law. The conductivity variant has been justified via the Rice and Roth model in which the number of free ions per unit volume, mobility and diffusion coefficient of free ions were obtained. [ABSTRACT FROM AUTHOR]

Polyethylene oxide (PEO) films doped with lithium acetate (LiOAc) were prepared by the solution cast technique. The molecular weight of PEO was 300 000 g mol-1. Lithium acetate was added to PEO in different weight ratios ranging from 0 to 30 wt-%. The PEO-LiOAc mixtures were dissolved in 1% acetic acid solution and stirred overnight. The highest electrical conductivity obtained for this system is 2·18 × 10-6 S cm-1 for the sample containing 30 wt-%CH3 COOLi. The conductivity-temperature study was carried out for all samples from 25 to 100°C. Different amounts of ethylene carbonate were added as a plasticiser. This resulted in the conductivity increasing to 1·46 × 10-5 S cm-1. [ABSTRACT FROM AUTHOR]