Electrochemical and spectroscopic study of the transport properties of composite polymer electrolytes (original) (raw)
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Studies on Solid Polymer Electrolyte Based on PEO/PVC Blends
2007
Novel polymer blend electrolyte was prepared using poly (ethylene oxide), polyvinyl chloride) and lithium perchlorate (LiCI0 4) as the complexing salt by employing solvent casting technique The prepared films were subjected to XRD, FTIR, ac impedance spectroscopy and thermogravimetry / differential thermal analysis (TQ/OTA) Quantitative analysis of the FTIR spectra provides the specific interactions between the constituents The thermal stability of the film is found using TG/DTA studies The maximum conductivity value of PVC (25)-PEO(75)~LiCI0 4 {8) film is found as 1 32 x 10 5 S/cm at room temperature As the PVC concentration increases in the electrolyte, the conductivity is found to decrease The temperature dependent ionic conductivity is also carried out in the temperature range 303-333K and the results are discussed
Transport and interfacial properties of composite polymer electrolytes
Electrochimica acta, 2000
Lithium polymer electrolytes formed by dissolving a lithium salt LiX in poly(ethylene oxide) PEO, may find useful application as separators in lithium rechargeable polymer batteries. The main problems, which are still to be solved for a complete successful operation of these materials, are the reactivity of their interface with the lithium metal electrode and the decay of their conductivity at temperatures below 70°C. In this paper we demonstrate that a successful approach for overcoming these problems, is the dispersion of selected ceramic powders in the polymer mass, with the aim of developing new types of composite PEO -LiX polymer electrolytes characterized by enhanced interfacial stability, as well as by improved ambient temperature transport properties.
Materials Chemistry and Physics, 2004
Composite polymer electrolyte films consisting of polyvinylchloride, polymethymethacrylate, dibutylphthalate, Li 2 SO 4 and also ZrO 2 particles have been prepared by a casting procedure. The effect of an inorganic filler on the ionic conductivity of the blend polymer electrolytes was studied. The results indicated the incorporation of the ceramic filler at a low level decreases the ionic conductivity of the material, while at the higher concentrations there is an improvement of the conductivity. From the temperature dependence of the ionic conductivity can be suggested that the ion conduction follows the Williams-Landel-Ferrry mechanism, which is confirmed by Vogel-Tammann-Fulcher plots.
Effect of complexing salt on conductivity of PVC/PEO polymer blend electrolytes
Bulletin of Materials Science, 2011
Solid polymer electrolyte membrane comprising poly(vinyl chloride) (PVC), poly(ehylene oxide) (PEO) and different lithium salts (LiClO 4 , LiBF 4 and LiCF 3 SO 3 ) were prepared by the solution casting technique. The effect of complexing salt on the ionic conductivity of the PVC/PEO host polymer is discussed. Solid polymer electrolyte films were characterized by X-ray diffraction, FTIR spectroscopy, TG/DTA and ac impedance spectroscopic studies. The conductivity studies of these solid polymer electrolyte (SPE) films are carried out as a function of frequency at various temperatures ranging from 302 K to 353 K. The maximum room temperature ionic conductivity is found to be 0⋅079 × 10 -4 S cm -1 for the film containing LiBF 4 as the complexing salt. The temperature dependence of the conductivity of polymer electrolyte films seems to obey the Vogel-Tamman-Fulcher (VTF) relation.
Thermochimica Acta, 2010
In this paper, temperature dependence of ionic conductivity, crystallographic structural, morphological and thermal characteristics of polymer blends of PMMA and PVC with lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) as a dopant salt are investigated. The study on the temperature dependence of ionic conductivity shows that these polymer blends exhibit Arrhenius behavior. The highest ionic conductivity was achieved when 70 wt% of PMMA was blended with 30 wt% of PVC. Xray diffraction (XRD) and scanning electron microscopy (SEM) reveal the amorphous nature and surface morphology of polymer electrolytes, respectively. In DSC analysis it was found that the glass transition temperature (T g ) and melting temperature (T m ) decreased, whereas the decomposition temperature (T d ) increased. In contrast, the shift towards higher decomposition temperature and decrease in weight loss of polymer electrolytes, in TGA studies, indicates that the thermal stability of polymer electrolytes improved.
2004
Thin films of polymer blend electrolytes comprising Poly(vinyl chloride) (PVC) and Poly(methyl methacrylate)(PMMA) and plasticized with a combination of ethylene carbonate (EC) and propylene carbonate (PC) for different lithium imide salt, LiN(C 2 F 5 SO 3 ) 2 , concentrations were prepared using the solution casting technique. The films were subjected to a. c. impedance measurements as a function of temperature ranging from -30 °C to 70 °C. The variation of ionic conductivity as a function of temperature and PVC content in the blend was analysed. The role of PMMA in the phenomena occurring at the interface between the plasticized polymer electrolyte and lithium electrode was also studied. The cast films were also subjected to TG/DTA and FT-IR studies which are discussed.
Solid State Ionics, 2015
Solid electrolytes based on poly(ethylene oxide)/poly(4-vinyl phenol-co-2-hydroxyethyl methacrylate) (PVPh-HEM) blends and LiClO 4 were obtained and characterized by differential scanning calorimetry (DSC), infrared vibrational spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). DSC curves showed a progressive decrease of crystallinity as the [O]:[M] ratio decreases in the polymer matrices and one glass transition temperature (T g) for all the samples, indicating that the original miscibility of the blend is maintained in the presence of LiClO 4. Analysis of the vibrational mode ν(COC) from the PEO chain suggests the complexation of Li + with the ether binding sites and, from a decomposition treatment employed to the vibrational spectra, the spectroscopic fractions of modes ν(C_O) and ν(ClO 4) were analyzed. The DSC and FTIR results allowed the elaboration of a molecular model to describe the cation-polymer interactions in the solid. From the impedance spectra, conductivity (σ) values were obtained as a function of [O]:[M] ratio and PVPh-HEM concentration in the polymer matrices. The σ values reached 10 −5 Ω −1 cm −1 for temperatures higher than 40°C and the electrolytes exhibited stability up to 3.5 V.
Physical and Chemical Properties of Nanocomposite Polymer Electrolytes
The Journal of Physical Chemistry B, 1999
The physical and chemical properties of a new class of lithium conducting polymer electrolytes formed by dispersing ceramic powders at the nanoscale particle size into a poly(ethylenoxide) (PEO)-lithium salt, LiX complexes, are reported and discussed. These true solid-state PEO-LiX nanocomposite polymer electrolytes have in the 30-80°C range an excellent mechanical stability (due to the network of the ceramic fillers into the polymer bulk) and high ionic conductivity (promoted by the high surface area of the dispersed fillers). These important and unique properties are accompanied by a wide electrochemical stability and by a good compatibility with the lithium electrode (assured by the absence of any liquids and by the interfacial stabilizing action of the dispersed filler), all this making these nanocomposite electrolytes of definite interest for the development of advanced rechargeable lithium batteries.
Investigation on the structure and the conductivity of plasticized polymer electrolytes
Solid State Ionics, 1992
Leiling Yang l)~7~artm ('plt ~l t'~d.t'tner Mat('rm/~. 1,¢et]mg Research l,~stilute ~!l' ('hcmtca/htdu.~try. I0(~013 B('!/in,~,,, t'.R ( 'hina Electrical properties of polymer electrolytes depend on the structure ot polym¢l matrix. It ~as reported that lranst)ortalion o1" carries in polymer electrolFles was correlated with tile segment movement oF the amorphous phase. D?namic properly of amorphous phase and the cwstallinit} of electrolyte would effecl the conducti~it~ of pol}mcr electrol}tes. The properties or" I)E() Li('F~SO~ modified with additives were investigated b~ conducti',ity measurement. I)S(' and ~tt-, "~F-NMR experiments. It was tbund [hat addilives would increase ~he conten! of amorphous phase and salt concentration m amorphous phase, and improve the dynamic property of amorphous phase. The spin-spin relaxation lime for the polymer matrix is also increased. It was indicated that the glass transition temperature of modified electrolFtcs was decreased from 21 (" Ior typical PE()-Li('F~S(), dectrolytes to about -48 C. These iml)ro~ements result in the increase of the conducf.iv il,v.
Lithium ion conducting solid polymer blend electrolyte based on bio-degradable polymers
Lithium ion conducting polymer blend electrolyte films based on poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) with different Mwt% of lithium nitrate (LiNO 3) salt, using a solution cast technique, have been prepared. The polymer blend electrolyte has been characterized by XRD, FTIR, DSC and impedance analyses. The XRD study reveals the amorphous nature of the polymer electrolyte. The FTIR study confirms the complex formation between the polymer and salt. The shifts in T g values of 70 PVA-30 PVP blend and 70 PVA-30 PVP with different Mwt% of LiNO 3 electrolytes shown by DSC thermograms indicate an interaction between the polymer and the salt. The dependence of T g and conductivity upon salt concentration has been discussed. The ion conductivity of the prepared polymer electrolyte has been found by a.c. impedance spectroscopic analysis. The PVA-PVP blend system with a composition of 70 wt% PVA: 30 wt% PVP exhibits the highest conductivity of 1•58 × 10 −6 Scm −1 at room temperature. Polymer samples of 70 wt% PVA-30 wt% PVP blend with different molecular weight percentage of lithium nitrate with DMSO as solvent have been prepared and studied. High conductivity of 6•828 × 10 −4 Scm −1 has been observed for the composition of 70 PVA:30 PVP:25 Mwt% of LiNO 3 with low activation energy 0•2673 eV. The conductivity is found to increase with increase in temperature. The temperature dependent conductivity of the polymer electrolyte follows the Arrhenius relationship which shows hopping of ions in the polymer matrix. The relaxation parameters (ω) and (τ) of the complexes have been calculated by using loss tangent spectra. The mechanical properties of polymer blend electrolyte such as tensile strength, elongation and degree of swelling have been measured and the results are presented.