Lithium Bonding in Acrylonitrile Copolymers and Nanocomposites with Ionic Conductivity (original) (raw)
Related papers
Journal of Applied Polymer Science, 2012
Copolymers of poly(acrylonitrile-co-ethyl methacrylate), P(AN-EMA), with three different EMA content and parent homopolymers were synthesized by emulsion polymerization. The chemical composition of copolymers were identified by FTIR, 1 H-NMR and 13 C-NMR spectroscopy. The thermal properties of copolymers were modified by changing the EMA content in copolymer compositions. Various amounts of LiClO 4 salt loaded (PAN-co-PEMA) copolymer films were prepared by solution casting. The dielectric properties of these films at different temperatures and frequencies were investigated. It was found that the dielectric constant and ac-conductivity of copolymer films were strongly influenced by the salt amounts and EMA content in copolymers. V
Polymer-in-Salt Electrolytes Based on Acrylonitrile/Butyl Acrylate Copolymers and Lithium Salts
Journal of Physical Chemistry B, 2004
Solid polymeric electrolytes for battery purposes in the form of composites of lithium salts [LiI, LiN(CF 3 SO 2 ) 2 , LiClO 4 , LiAlCl 4 , LiCF 3 SO 3 , and LiBF 4 ] and acrylic polymeric matrixes [poly(acrylonitrile-co-butyl acrylate), poly(methyl methacrylate), and poly(butyl acrylate)] have been obtained by film casting from acetonitrile. The ionic conductivity (σ) as a function of temperature was studied by the impedance spectroscopy method. These systems show the highest σ values, on the order of 10 -4 -10 -7 S‚cm -1 , at high salt concentrations (above 50 wt %), characteristic of polymer-in-salt electrolytes. The ionic conductivity and mechanical properties of composites depend on the chemical structure of the polymer matrix, the anion, and the salt concentration. The glass transition temperature (T g ) was determined from DSC studies. The introduction of a salt causes, in a majority of the composites studied, a considerable decrease in the T g values, indicating a strong plasticizing effect. DSC studies show a multiphase character of the composites, in which, with the exception of the amorphous system with LiN(CF 3 SO 2 ) 2 , phases of the plasticized matrix, complexes of the salt with the matrix of varying stoichiometry, and often the separating salt are observed. The logarithm of the decoupling index (log R τ ) on the order of 3-5 as well as the shift in the IR spectrum of the groups present in the polymer (CtN and CdO) by about 20-30 cm -1 indicate a weak interaction of the salt with the matrix. The ion transference numbers (0.5-0.8) determined by the electrochemical method indicate an increased participation of cations in the electrical charge conduction and a different conduction mechanism compared to that of classical electrolytes based on complexes with polyethers.
Solid State Ionics, 2005
Novel “polymer-in-salt“ electrolytes were prepared by mixing random copolymers of acrylonitrile and butyl acrylate [poly(AN-co-BuA)] with lithium bis(trifluoromethanesulfone)imide (LiTFSI). The interaction of Li+ ions and polymeric groups was investigated by DSC and IR methods; electrical properties were studied by impedance spectroscopy. The properties of the new system were compared to those of the well-known poly(ethylene oxide) (PEO)–LiTFSI polymer electrolytes. The mixtures of poly(AN-co-BuA) and LiTFSI exhibit much lower glass transition temperature Tg than the parent copolymer (decrease of over 60 K for high salt content). By extrapolation of the dependence of the Tg on the salt content, the value of Tg for pure LiTFSI was estimated as 232 K. The decrease of Tg was correlated with the increase of the decoupling index, Rτ, which is proportional to the value of conductivity measured at Tg. The interactions of LiTFSI with poly(AN-co-BuA) lead to high flexibility of this system; a property that is opposite to the behavior of the PEO–LiTFSI system, where interactions between the salt and polyether lead to stiffening of the polymer with increasing salt content.
Performance of acrylate-poly(ethylene oxide) polymer electrolytes in lithium batteries
Journal of Applied Electrochemistry, 1993
Results for the performance of lithium/MnO2 batteries containing solid polymer electrolytes based on poly(ethylene oxide) blends with some acrylic derivatives are presented. The ionic conductivities of the electrolytes are promising for battery application. It was found, however, that interfacial phenomena impair the battery efficiency. Impedance spectroscopy shows resistive limitations at the anode interface of the batteries, caused either by formation of an electrically distinguishable resistive layer or by chemical interaction between the polymer and lithium, influencing, most probably, the kinetics of the lithium oxidation reaction.
2012
The synthesis, diffraction patterns, thermal stability, and ionic conductivity properties of methacrylate-type polymers are analyzed here to assess their feasibility as polymer electrolytes. From the parent polymer, poly (N,N-dimethylaminoethylmethacrylate), herein labeled PDMAEMA, a protonated derivative was used to prepare polymer/Montmorillonite nanocomposites with various clay contents (1, 3, and 5 wt %). AC spectroscopy provided the ionic conductivity data for the polymers and clay-polymer nanocomposites. Evidences of nanocomposite formation are shown using transmission electron microscopy and wide-angle X-ray diffraction.
Journal of Non-Crystalline Solids, 2011
Ionic conductivity, diffusion coefficients, mobility and ionic concentration for lithium salts dissolved in polymer electrolytes are determined by the modeling of the dielectric loss and spectra. Cation and anion diffusion coefficients are quantified using the Trukhan model depending on the assumed ratio of the cation to anion diffusion coefficients. Measurements are performed for polymer electrolytes consisting of polyethylene oxide (PEO) with dissolved LiClO 4 salts for different sample thicknesses and temperatures ranging from 5 to 105°C, which comprises both the crystalline and amorphous phases of the composite electrolyte. A good phenomenological description of the dielectric loss spectra is obtained for both the semi-crystalline and amorphous phases. The fraction of mobile ions is estimated to vary from 0.002% at 25°C (semi-crystalline phase) up to 0.05% at 80°C (amorphous phase).
Arabian Journal of Chemistry, 2018
Effect of binary lithium salts (lithium tetrafluoroborate, LiBF 4 with lithium trifluoromethanesulfonate, LiCF 3 SO 3) and (lithium tetrafluoroborate, LiBF 4 with Lithium iodide, LiI) as charge carriers in solid polymer electrolyte based 49% poly(methyl methacrylate) grafted natural rubber (MG49) for Li-ion battery application has been investigated. The polymer electrolytes were prepared by solution casting technique. The effect of binary lithium salts on chemical interaction, structural, thermal studies, ionic conductivity and ion transference number of MG49 films are analyzed by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC) and electrochemical impedance spectroscopy (EIS). Infrared analysis indicated the interaction occurred between Li ions and oxygen atoms at the carbonyl group (−C=O) and the ether group (C−O−C) on methyl methacrylate (MMA) segments. XRD studies exhibited a reduction of the MMA peak intensity at 29.5˚ after the addition of different ratios of binary Li salts due to the plasticizing effect of the salts. The larger anion size tends to create bigger free volume in the polymer electrolyte. In addition, this confirms that the degree of crystallinity of the electrolyte films is reduced leading to enhancement of ionic conductivity. DSC results revealed the highest conductivity sample has the lowest T g implying the ions can flow with more ease throughout the polymer chain. The ratios of LiBF 4 :LiI presenting the higher overall performance in terms of ionic conductivity comparing to LiBF4:LiCF 3 SO 3 ratios in MG49. The highest room temperature conductivity was obtained at 1.89 × 10-6 S cm-1 for 2 (30:70) LiBF 4 :LiI percentages ratio. Moreover, t ion is observed to increase with the ionic conductivities.
Concentration dependence of ionic relaxation in lithium doped polymer electrolytes
Journal of Non-Crystalline Solids, 2010
This is an author produced version of a paper published in Journal of Non-Crystalline Solids. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination. Citation for the published paper: Furlani, M. et. al. "Concentration dependence of ionic relaxation in lithium doped polymer electrolytes"
Journal of Polymer Science Part B: Polymer Physics, 2010
The use of lithium cation in composites of block copolymers [polyethylene-b-polyethylene oxide (PE-b-50%PEO and PE-b-80%PEO)] and their derivatives was tested as a modifier of the vapor sorption and impedance of these complexes. The block copolymer PE-b-80%PEO was modified by oxidation of its hydroxyl end group to both a carboxylic acid group (PE-b-80%PEO)CH 2 COOH and its sodium salt (PE-b-80%PEO)CH 2 COO À Na þ for the purpose of improving its compatibility and performance as a matrix for composites. These modified copolymers were characterized by FTIR, DSC, and mass spectrometry. The sorption of water of these copolymers and their composites with lithium nitrate was also compared, as well as the electrical properties of their composites were measured by electrical impedance spectroscopy. For the composites obtained with PE-b-80%PEO and lithium nitrate, it was found that lithium cation plays an important role increasing the sorption rate, which is maximized for the PE-b-80%PEO þ (21% lithium nitrate) composite. For the copolymers (PE-b-80%PEO)CH 2 COOH and (PE-b-80%PEO)CH 2 COO À Na þ and their composites, the highest sorption rate was observed for salt in the following order: COO À Na þ > COOH > OH. The PE-b-80%PEO þ (21% lithium nitrate) composite behaves as a solid polymeric ionic conductor fitting the Williams-Landel-Ferry equation. However, both (PE-b-80% PEO)CH 2 COOH and (PE-b-80%PEO)CH 2 COO À Na þ þ (21% lithium nitrate) composites fitted the Variable Range Hopping equation, indicating a conductance trend with temperature governed by a thermally activated with energy of 0.482 and 0.524 eV and not by a relaxation process. V