Effect of PBMA on PVC‐based polymer blend electrolytes

Poly(vinyl chloride) (PVC)—poly(butyl methacrylate) (PBMA) blended polymer electrolytes with lithium perchlorate (LiClO₄) as the complexing salts are prepared by solution casting technique. The addition of PBMA into PVC matrix is found to induce considerable changes in physical and electrical properties of the polymer electrolytes. Addition of PBMA into PVC matrix is found to increase the conductivity by two orders of magnitude (1.108 × 10^?5 S cm^?1) when compared with that of the pristine PVC polymer electrolyte (10^?7 S cm^?1). Structural, thermal, mechanical, morphological, and polymer–salt interactions are ascertained from X‐ray diffraction (XRD), thermogravimetry/differential thermal analysis (TG/DTA), mechanical analysis, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) respectively. A thermal stability upto 250 °C is asserted from the TG/DTA analysis. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44939.     

Enhanced electrical and electrochemical properties of PMMA-clay nanocomposite gel polymer electrolytes

In the present work, effect of organically modified montmorillonite (MMT) clays on PMMA-based electrolytes has been investigated. The nanocomposites have been prepared by solution intercalation technique with varying clay loading from 0 to 5 wt.%. The formation of partially exfoliated nanocomposites has been confirmed by XRD and TEM analyses. The obtained nanocomposites were soaked with 1 M LiClO₄ in 1:1 (v/v) solution of propylene carbonate (PC) and diethyl carbonate (DEC) to get the required gel electrolytes. Surface morphology and structural conformation of the nanocomposite electrolytes have been examined by SEM and FTIR analyses, respectively. It has been observed that the ionic conductivity of the nanocomposite gel polymer electrolytes increases with the increase in clay loading and attains a maximum value of 1.3 × 10⁻³ S/cm at room temperature as revealed by ac impedance spectroscopy. Improvement of electrochemical and interfacial stabilities has also been observed in the gel electrolytes containing MMT fillers.     

Ionic conduction in P(VDF-HFP)/PVDF-(PC + DEC)-LiClO4 polymer gel electrolytes

Gel polymer electrolytes composed of poly(vinylidene fluoride-hexafluoropropylene) copolymer, poly(vinylidene fluoride) polymer, PC+DEC as plasticizer and LiClO₄ as salt have been synthesized by solvent casting technique with varying the plasticizer-salt concentration ratio systematically. Complex impedance spectroscopy has been carried out to investigate ionic conduction in P(VDF-HFP)-(PC+DEC)-LiClO₄ and PVDF-(PC+DEC)-LiClO₄ electrolyte systems. Transport number measurements have been made by Wagner’s polarization technique. With all other parameters same, P(VDF-HFP) electrolytes exhibit higher ionic conductivity and transport number as compared to PVDF based electrolytes which could be attributed to higher degree of amorphicity in the P(VDF-HFP) system. XRD and FTIR studies have been conducted to investigate the structural and complexation in the polymer gel electrolytes. Microstructural studies by SEM exhibit higher amorphicity and solvent retention capability for P(VDF-HFP)-(PC+DEC)-LiClO₄ system than those of PVDF-(PC+DEC)-LiClO₄ system.     

Lithium Ion-conducting Blend Polymer Electrolyte Based on PVA–PAN Doped with Lithium Nitrate

A new blend polymer electrolyte based on poly(vinyl alcohol) and polyacrylonitrile doped with lithium nitrate (LiNO₃) has been prepared and characterized. The complexation of blend polymer (92.5 PVA:7.5 PAN) with LiNO₃ has been studied using X-ray diffraction and Fourier transform infrared spectroscopy. Differential scanning calorimetry thermograms show a decrease in glass transition temperature with the addition of salt. The maximum ionic conductivity of the blend polymer electrolyte is 1.5 × 10^?3 Scm^?1 for 15 wt% LiNO₃ doped–92.5 PVA:7.5 PAN electrolyte. The conductivity values obey Arrhenius equation. Ionic transference number measurement reveals that the conducting species are predominantly ions.     

Ionic conductivity of solid polymer electrolytes for dye‐sensitized solar cells

We developed an ionic conductivity model of solid polymer electrolytes for dye‐sensitized solar cells (DSSCs) based on the Nernst–Einstein equation in which the diffusion coefficient is derived from the molecular thermodynamic model. We introduced concentration‐dependence of the diffusion coefficient into the model, and the diffusion coefficient was expressed by differentiating the chemical potential by concentration. The ionic conductivities of polymer electrolytes (PEO/LiI/I₂ system) were investigated at various temperatures and compositions. We prepared a set of PEO in which an EO : LiI mole ratio of 10 : 1 was kept constant for PEO·LiI·(I₂)_n compositions with n = 0.02, 0.05, 0.1, 0.15, 0.2, and 0.3 (mole ratio of LiI : I₂). The ionic conductivities of the electrolytes were measured using a stainless steel/polymer‐electrolyte/stainless steel sandwich‐type electrode structure using alternating current impedance analysis. The values calculated using the proposed model agree well with experimental data. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

New solid polymer electrolytes based on PEO/PAN hybrids

Hybrid polymer dry electrolytes comprised of poly(ethylene oxide) (PEO), polyacrylonitrile (PAN), and LiClO₄ were investigated. The impedance spectroscopy showed that the effect of PAN on the ion conductivity of PEO‐based electrolytes depends on the concentration of lithium salt. When the mole ratio of lithium to oxygen is 0.062 (15%LiClO₄‐PEO), adding PAN will increase the ionic conductivity. Differential scanning calorimetry, NMR, and IR data suggested that the enhanced conductivity was due to both the decreasing of the PEO crystallinity and increasing of the degree of ionization of lithium salt. There was obviously no interaction between PAN and lithium ions, and PAN acts as a reinforcing filler, and hence contributes to the mechanical strength besides reducing the crystallinity of the polymer electrolytes. When the LiClO₄‐PEO‐PAN hybrid polymer electrolyte was heated at 200°C under N₂, PAN crosslinked partially, which further decreased the crystallinity of PEO and increased the ionic conductivity, and at the same time prevented the recrystallization of PEO upon sitting at ambient environment. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1530–1540, 2006     

Nanocomposite polymer electrolytes by in situ polymerization of methyl methacrylate: For electrochemical applications

Hybrid materials, which combine properties of organic–inorganic materials, are of profound interest owing to their unexpected synergistically derived properties and are considered as innovative advanced materials promising new applications in many fields such as optics, electronics, ionics and mechanics. Inorganic fillers are added to polymers in order to increase some of the properties of the compounds. These hybrid polymeric materials are replacing the pristine polymers due to their higher strength and stiffness. In the present work, studies concerning the preparation of poly (methylmethacrylate) [PMMA] and the nanocomposites PMMA/SiO₂, PMMA/TiO₂ are reported. These nanocomposite polymers were synthesized by means of free radical polymerization of methylmethacrylate, further “sol–gel” transformation‐based hydrolysis and condensation of corresponding alkoxide was used to prepare the inorganic phase during the polymerization process of MMA. Electrolytes were synthesized based on these nanocomposite polymers and have shown superior properties as compared to conventional polymer electrolytes. The nanocomposites and the nanocomposite polymer electrolytes (NPEs) with different lithium salts were investigated through an array of techniques including FTIR and calorimetry along with the electrochemical and rheological techniques. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of nanofiller concentration on conductivity and dielectric properties of poly(ethylene oxide)–poly(methyl methacrylate) polymer electrolytes

This paper reports the effect of nanofiller concentration on the conductivity and dielectric properties of the poly(ethylene oxide)–poly(methyl methacrylate)–poly(ethylene glycol)–AgNO₃–Al₂O₃ polymer electrolyte system. The preparation of polymer films was done using the solution‐casting technique and characterization of the films was carried out using scanning electron microscopy, differential scanning calorimetry and ionic transport techniques. The ionic conductivity, investigated using impedance spectroscopy, was expected to show interesting behaviour at below and above the melting temperature of poly(ethylene oxide) in the polymer blend films. Complex impedance data were analysed in an alternating current conductivity and dielectric permittivity formalism in order to throw light on the transport mechanism. The effect of nanofiller concentration on conduction and relaxation processes at various temperatures was studied. © 2013 Society of Chemical Industry     

Characterizations of proton conducting polymer electrolytes for electrochemical capacitors

Solid polymer electrolytes containing phosphotungstic acid (PWA) and/or silicotungstic acid (SiWA) in polyvinyl alcohol (PVA) were investigated for their proton conductivities. Enhanced conductivity was obtained when mixing PWA and SiWA at equal ratio. This polymer electrolyte was found viable for electrochemical capacitors. Thermal and structural analyses were conducted with DSC, XRD, and FTIR. The polymer electrolyte exhibited a different structure and different thermal properties from its respective components. The polymer electrolyte retained its original Keggin structure but contained crystallized protonated water in the form of H₅O₂⁺. The protonated water may contribute to the proton conductivity of the polymer electrolyte.     

Lithium difluoro(oxalate)borate‐based novel nanocomposite polymer electrolytes for lithium ion batteries

BACKROUND: HF formation and poor thermal stability found in commercial lithium ion batteries comprising LiPF₆ (and other salts) have hampered the replacement of LiPF₆. Therefore, a new kind of electrolyte salt is necessary to replace the one commercially available. RESULTS: A novel lithium difluoro(oxalate)borate (LiDFOB)‐based nanocomposite polymer electrolyte has been prepared in a matrix of poly[(vinylidene fluoride)‐co‐(hexafluoropropylene)] (PVdF‐HFP). The electrolyte contains ethylene carbonate and diethyl carbonate as plasticizers and nanoparticulate Sb₂O₃ as a filler. Membranes obtained by a solution casting technique were characterized by AC impedance, thermogravimetry and tensile strength measurements and morphological studies. Membranes with 5 wt% Sb₂O₃ exhibit a room‐temperature conductivity of 0.298 mS cm^?1, and are thermally stable up to ca 130 °C. Furthermore, the nanocomposite membranes show a 125% increase in mechanical stability as compared to filler‐free membranes. The structural change from α to β phases was confirmed by Raman studies. CONCLUSION: One of the important advantages of using LiDFOB lies in its bulkier DFOB anion, which also acts as solid plasticizer, thus improving the basic requirements of the electrolyte, such as mechanical and thermal stabilities, as well ionic conductivity and with a lower filler content. The overcharge tolerance of LiDFOB salt at higher temperature is also to be noted, because of the oxalate moieties. Preliminary investigations confirmed the possibility of using Sb₂O₃ nanoparticle‐filled membranes in industry in the near future. Copyright © 2008 Society of Chemical Industry     

Fabrication and characterization of a solid polymeric electrolyte of PAN‐TiO2‐LiClO4

The ionic conductivity of PAN‐TiO₂‐LiClO₄ as a function of TiO₂ concentration and temperature has been reported. The electrolyte samples were prepared by solution casting technique. Their conductivity was measured using the impedance spectroscopy technique. The highest room temperature conductivity of 1.8 × 10^?4 S cm^?1 was obtained at 7.5 wt % of TiO₂ filler. It was observed that the relationship between temperature and conductivity were linear, fitting well in Arrhenius and not in Vogel‐Tamman‐Fulcher equation. The pre‐exponential factor, σ₀ and E_a are 1.8 × 10^?4 S cm^?1 and 0.15 eV, respectively. The conductivity data have been supported by differential scanning calorimeter (DSC) analysis. DSC analysis showed that there was a significant change in glass transition temperature (T_g) with the filler concentration. The SEM micrograph revealed that the TiO₂ particles are dispersed in the electrolyte, thus enhancing its conductivity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis of elastin‐based polymer and evaluation of its intermolecular interactions with hydroxypropyl methylcellulose

The parent repeating sequence of elastin, poly(GVGVP), was synthesized using solution phase method and characterized by ¹³C‐ and ¹H‐NMR spectroscopy. In order to study the polymer–polymer interactions between poly(GVGVP) and hydroxyl propyl methyl cellulose (HPMC), the blends were prepared both in aqueous and solid phase and examined using various analytical techniques. The viscometric measurements have been carried out at 24 °C and the interaction parameters such as α, β, µ, and Δ[η]_m revealed the miscible nature of the poly(GVGVP)/HPMC blend systems. In addition, Fourier‐transform infrared spectroscopy showed the formation of strong intermolecular hydrogen bond between poly(GVGVP) and HPMC networks. This result was further supported by glass transition temperature (T_g), scanning electron microscopic, and X‐ray diffraction studies. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45283.     

Synthesis and characterization of LiBOB‐based PVdF/PVC‐TiO2 composite polymer electrolytes

Synthesis and characterization of composite polymer electrolytes based on lithium bis(oxalato)borate (LiBOB) and a host matrix of nanoparticulate anatase dispersed in phase‐separated poly(vinylidenefluoride) (PVdF)‐poly(vinylchloride) (PVC) are described. Ethylene carbonate (EC) and diethyl carbonate (DEC) were used as plasticizers in the membranes, and nanoparticulate TiO₂ (anatase) was used as the filler. The membranes were characterized by SEM, XRD, and a.c. impedance measurements. A membrane with 2.5 wt% filler exhibited a conductivity of 5.43 × 10^?4 S.cm^?1 at ambient temperature. Filler levels above 2.5 wt% increased the crystallinity of the membranes, rendering them less conducting. Activation energy and coherent length of the composite polymer electrolytes have also been calculated. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers.     

Structure–property relationship of polyethylene glycol‐based PU/PAN semi‐interpenetrating polymer networks

Polyethylene glycol‐400 (PEG) based polyurethane (PU) and polyacrylonitrile (PAN) semi‐interpenetrating polymer networks (SIPNs) (PU/PAN; 90/10, 70/30, 60/40, and 50/50) have been prepared by sequential polymerization method. The prepared SIPNs have been characterized by physicomechanical properties. The microcrystalline parameters such as crystal size (〈N〉), lattice disorder (g), surface (D_s) and volume (D_v) weighted crystal size of SIPNs have been estimated using wide angle X‐ray scattering studies, and quantification of the polymer network has been carried out on the basis of these parameters. The microstructural parameters have been established using Exponential, Lognormal, and Reinhold asymmetric column length distribution functions and the results are compiled. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 177–187, 2006     

Composite polymer electrolytes based on the low crosslinked copolymer of linear and hyperbranched polyurethanes

Low crosslinked copolymer of linear and hyperbranched polyurethane (CHPU) was prepared, and the ionic conductivities and thermal properties of the composite polymer electrolytes composed of CHPU and LiClO₄ were investigated. The FTIR and Raman spectra analysis indicated that the polyurethane copolymer could dissolve more lithium salt than the corresponding polymer electrolytes of the non crosslinked hyperbranched polyurethane, and showed higher conductivities. At salt concentration EO/Li = 4, the electrolyte CHPU30‐LiClO₄ reached its maximum conductivity, 1.51 × 10^?5 S cm^?1 at 25°C. DSC measurement was also used for the analysis of the thermal properties of polymer electrolytes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3607–3613, 2007     

Characterization of PEO-PAN hybrid solid polymer electrolytes

Hybrid solid polymer electrolytes (HSPE) of high ionic conductivity were prepared using polyethylene oxide (PEO), polyacrylonitrile (PAN), propylene carbonate (PrC), ethylene carbonate (EC), and LiClO₄. These electrolyte films were dry, free standing, and dimensionally stable. The HSPE films were characterized by constructing symmetrical cells containing nonblocking lithium electrodes as well as blocking stainless steel electrodes. Studies were made on ionic conductivity, electrochemical reaction, interfacial stability, and morphology of the films using alternating current impedance spectroscopy, infrared spectroscopy, and scanning electron microscopy. The properties of HSPE were compared with the films prepared using (i) PEO, PrC, and LiClO₄; and (ii) PAN, PrC, EC, and LiClO₄. The specific conductivity of the HSPE films was marginally less. Nevertheless, the dimensional stability was much superior. The interfacial stability of lithium was similar in the three electrolyte films. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2191–2199, 1997     

Effect of plasticizers in poly(vinyl alcohol)‐based hybrid solid polymer electrolytes

Hybrid solid polymer electrolyte films consisting of poly(vinyl alcohol) (PVA), poly(methyl methacrylate) (PMMA), LiBF₄, and ethylene carbonate/propylene carbonate (EC/PC) were prepared with a solvent‐casting technique. The complexation was investigated with Fourier transform infrared and X‐ray diffraction. The ionic conductivities of the electrolyte films were determined with an alternating‐current impedance technique for various temperatures in the range of 302–373 K. The maximum conductivity value, 1.2886 × 10^?3 S/cm, was observed for a PVA–PMMA–LiBF₄–EC complex. Thermogravimetry/differential thermal analysis was performed to ascertain the thermal stability of the electrolyte with the maximum conductivity value. For an examination of the cyclic and reversible performance of the film, a cyclic voltammetry study was carried out. The surface morphology of the EC‐and PC‐based electrolytes was examined with scanning electron microscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2794–2800, 2003     

Electrochemical investigations on the effect of dispersoid in PVA based solid polymer electrolytes

Various compositions of TiO₂ dispersed PVA‐PMMA‐LiBF₄‐EC based electrolytes were prepared using solution casting technique. The prepared electrolytes were characterized using AC impedance, XRD, SEM, FTIR, etc. The ionic conductivity value is increased with the increase in filler content (up to 8 wt %) and then decreased with the increase in filler content. The results are described using Vogel–Tamman–Fulcher theory. The thermal and transport properties of the electrolyte exhibiting maximum conductivity have also been studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3950–3956, 2007     

Studies of solvent effect on the conductivity of 2‐mercaptopyridine‐doped solid polymer blend electrolytes and its application in dye‐sensitized solar cells

Solvents and electrolytes play an important role in the fabrication of dye‐sensitized solar cells (DSSCs). We have studied the poly(ethylene oxide)‐poly(methyl methacrylate)‐KI‐I₂ (PEO‐PMMA‐KI‐I₂) polymer blend electrolytes prepared with different wt % of the 2‐mercaptopyridine by solution casting method. The polymer electrolyte films were characterized by the FTIR, X‐ray diffraction, electrochemical impedance and dielectric studies. FTIR spectra revealed complex formation between the PEO‐PMMA‐KI‐I₂ and 2‐mercaptopyrindine. Ionic conductivity data revealed that 30% 2‐mercaptopyridine‐doped PEO‐PMMA‐KI‐I₂ electrolyte can show higher conductivity (1.55 × 10^?5 S cm^?1) than the other compositions (20, 40, and 50%). The effect of solvent on the conductivity and dielectric of solid polymer electrolytes was studied for the best composition (30% 2‐mercaptopyridine‐doped PEO‐PMMA‐KI‐I₂) electrolyte using various organic solvents such as acetonitrile, N,N‐dimethylformamide, 2‐butanone, chlorobenzene, dimethylsulfoxide, and isopropanol. We found that ac‐conductivity and dielectric constant are higher for the polymer electrolytes processed from N,N‐dimethylformamide. This observation revealed that the conductivity of the solid polymer electrolytes is dependent on the solvent used for processing and the dielectric constant of the film. The photo‐conversion efficiency of dye‐sensitized solar cells fabricated using the optimized polymer electrolytes was 3.0% under an illumination of 100 mW cm^?2. The study suggests that N,N‐dimethylformamide is a good solvent for the polymer electrolyte processing due to higher ac‐conductivity beneficial for the electrochemical device applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42489.