FTIR characterization of PEO + LiN(CF3SO2)2 electrolytes

A series of polymer nanocomposite films based on intercalation of (PAN) 8 LiCF 3 SO 3 into the nanometric clay channels of an organomodified clay has been prepared using the standard solution-casting technique. The role of organoclay concentration on polymer-ion interaction, ion-ion interaction, and ion-clay interaction in clay-based nanocomposite films has been analyzed using Fourier transform infrared (FTIR) analysis. Substantial ion dissociation is observed even at a very low clay loading (1-2 wt.%) in the nanocomposites. FTIR results suggest the presence of both uncoordinated CF 3 SO 3 − (free-anions) and ion pairs in the nanocomposite evidenced by changes in CF 3 SO 3 − symmetry from C3ν to Cs and marked asymmetry in the profile of degenerate δ d (CF 3 − ) mode. The experimental results suggest a direct correlation of clay-assisted ion dissociation process with variation in conductivity (σ dc ) and glass transition temperature (T g ) as a function of clay concentration. A model has been proposed to explain the observed correlation on the basis of polymer-ion-clay interaction. The proposed scheme of ion transport mechanism appears to be consistent with the experimental observation.

Section: Materials Characterizationcontrasting

confidence: 79%

Polymer–ion–clay interaction based model for ion conduction in intercalation-type polymer nanocomposite

Sharma

Thakur

2009

“…7b and c, respectively. From the spectra, these bands became less intense but have similar shape due to the effect of CF 3 SO 3 anion [22]. In the region of 1,300-1,150 cm −1 , CH 2 twisting mode was observed at 1,241 and 1,279 cm −1 .…”

Section: Resultsmentioning

confidence: 86%

Morphology, chemical interaction, and conductivity of a PEO-ENR50 based on solid polymer electrolyte

Noor

Ahmad

Talib

et al. 2009

149

A solid polymer electrolytes (SPE) comprising blend of poly(ethylene oxide; PEO) and epoxidized natural rubber as a polymer host and LiCF 3 SO 3 as a dopant were prepared by solution-casting technique. The SPE films were characterized by field emission scanning electron microscopy to determine the surface morphology, X-ray diffraction, and differential scanning calorimeter to determine the crystallinity and thermogravimetric analysis to confirm the mass decrease caused by loss of the solvent. While the presence of the complexes was investigated by reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Electrochemical impedance spectroscopy was conducted to obtain ionic conductivity. Scanning electron microscopy analysis showed that a rough surface morphology of SPE became smoother with addition of salt, while ATR-FTIR spectroscopy analysis confirmed the polymer salt complex formation. The interaction occurred between the salt, and ether group of polymer host where the triple peaks of ether group in PEO merged and formed one strong peak at 1,096 cm −1 . Ionic conductivity was found to increase with the increase of salt concentration in the polymer blend complexes. The highest conductivity achieved was 1.4× 10 −4 Scm −1 at 20 wt.% of LiCF 3 SO 3 , and this composition exhibited an Arrhenius-like behavior with the activation energy of 0.42 eV and the preexponential factor of 1.6×10 3 Scm −1 .

“…These conformational changes, which correspond to those of infrared active vibrational bands involving ether oxygen, indicate the complexation of alkali metal ion to the ether oxygen [20,21]. (2) The strong broad absorption band appearing in the 2,950-2,700 cm −1 region in pure PEO corresponds to symmetric and asymmetric C-H stretching modes of the CH 2 group [20]. The width of this band in PEO was found to decrease with an increasing dopant concentration.…”

Section: Experimental Descriptionmentioning

confidence: 96%

“…(1) In the spectral range 1,050-1,150 cm −1 , significant changes are observed in the width and the intensity of the vibrational bands of PEO on the addition of NaFeF 4 at different concentrations. These conformational changes, which correspond to those of infrared active vibrational bands involving ether oxygen, indicate the complexation of alkali metal ion to the ether oxygen [20,21]. (2) The strong broad absorption band appearing in the 2,950-2,700 cm −1 region in pure PEO corresponds to symmetric and asymmetric C-H stretching modes of the CH 2 group [20].…”

Section: Experimental Descriptionmentioning

confidence: 99%

Ion transport and battery discharge characteristics of polymer electrolyte based on PEO complexed with NaFeF4 salt

Mohan

Raja

Sharma

et al. 2006

Ion-conducting solvent-free solid polymer electrolytes based on polyethylene oxide (PEO) complexed with sodium ferric tetrafluoride (NaFeF 4 ) were prepared using a solution casting technique. The complexation of the films was investigated through X-ray diffraction and Fourier transform infrared spectroscopic studies. Measurements of DC conductivity in the temperature range 300-370 K and the transference numbers were carried out to investigate the nature of charge transport in the polymer electrolyte system. Transference number data shows that the charge transport in this system is found to be predominantly due to ions. Using these polymer electrolytes, electrochemical cells were fabricated with the configuration of Na/(PEO+NaFeF 4 )/ (I 2 +C+electrolyte). Various cell parameters, such as open circuit voltage, short circuit current, power density, and energy density of the device were evaluated and reported.