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1.
A proton-conducting polymer electrolyte based on starch and ammonium nitrate (NH 4NO 3) has been prepared through solution casting method. Ionic conductivity for the system was conducted over a wide range of
frequency between 50 Hz and 1 MHz and at temperatures between 303 K and 373 K. Impedance analysis shows that sample with 25 wt.%
NH 4NO 3 has a smaller bulk resistance ( R
b) compared to that of the pure sample. The amount of NH 4NO 3 was found to influence the proton conduction; the highest obtainable room temperature conductivity was 2.83 × 10 −5 S cm −1, while at 100 °C, the conductivity in found to be 2.09 × 10 −4 S cm −1. The dielectric analysis demonstrates a non-Debye behavior. Transport parameters of the samples were calculated using the
Rice and Roth model and thus shows that the increase in conductivity is due to the increase in the number of mobile ions. 相似文献
2.
An attempt has been made in the present work to combine gel and composite polymer electrolyte routes together to form a composite
polymeric gel electrolyte that is expected to possess high ionic conductivity with good mechanical integrity. Polyethylene
glycol (PEG) based composite gel electrolytes using polyvinyl alcohol (PVA) as guest polymer have been synthesized with 1
molar solution of ammonium thiocyanate (NH 4SCN) in dimethyl sulphoxide (DMSO) and electrically characterized. The ionic conductivity measurements indicate that PEG:PVA:NH 4SCN-based composite gel electrolytes are superior ( σ
max = 5.7 × 10 −2 S cm −1) to pristine electrolytes (PEG:NH 4SCN system) and conductivity variation with filler concentration remains within an order of magnitude. The observed conductivity
maxima have been correlated to PEG:PVA:NH 4SCN-and PVA:NH 4SCN-type complexes. Temperature dependence of conductivity profiles exhibits Arrhenius behaviour in low temperature regime
followed by VTF character at higher temperature.
相似文献
3.
Development and characterisation of polyethylene oxide (PEO)-based nanocomposite polymer electrolytes comprising of (PEO-SiO 2): NH 4SCN is reported. For synthesis of the said electrolyte, polyethylene oxide has been taken as polymer host and NH 4SCN as an ionic charge supplier. Sol–gel-derived silica powder of nano dimension has been used as ceramic filler for development
of nanocomposite electrolytes. The maximum conductivity of electrolyte ∼2.0 × 10 −6 S/cm is observed for samples containing 30 wt.% silica. The temperature dependence of conductivity seems to follow an Arrhenius-type,
thermally activated process over a limited temperature range. 相似文献
4.
Solid polymer electrolytes based on poly(vinyl alcohol) (PVA) doped with NH 4Br have been prepared by the solution-casting method. The complex formation between the polymer and the salt has been confirmed
by Fourier transform infrared spectroscopy. The highest conductivity at 303 K has been found to be of the order of 10 −4 Scm −1 for 25 mol% NH 4Br-doped PVA system. The ionic transference number of polymer electrolyte has been estimated by Wagner’s polarization method,
and the results reveal that the conducting species are predominantly ions.
Paper presented at the Third International Conference on Ionic Devices (ICID 2006), Chennai, Tamilnadu, India, Dec. 7–9, 2006. 相似文献
5.
The plasticized polymer electrolyte consisting of poly(epichlorohydrin-ethyleneoxide) [P(ECH-EO)], lithium perchlorate (LiClO 4) and γ-butyrolactone (γ-BL) have been prepared by simple solution casting technique. The polymer–salt–plasticizer complex
has been confirmed by XRD analysis. The ionic conductivity studies have been carried out using AC impedance technique. The
effect of plasticizer (γ-BL) on ionic conductivity has been discussed with respect to different temperatures. The maximum
value of ionic conductivity is found to be 1.3 × 10 −4 Scm −1 for 70P(ECH-EO):15γ-BL:15LiClO 4 at 303 K. The temperature dependence of the plasticized polymer electrolyte follows the Vogel–Tamman–Fulcher formalism. The
activation energy is found to decrease with the increase in plasticizer. 相似文献
6.
Hybrid solid polymer electrolyte films comprising of poly(vinyl acetate) (PVAc), poly(methyl methacrylate) (PMMA), LiClO 4, and propylene carbonate are prepared by solution casting technique by varying the salt concentration. In this study, PVAc/PMMA
polymer blend ratio is fixed as 25:75 on the basis of conductivity and mechanical stability of the film. X-ray diffraction,
Fourier transform infrared impedance, thermogravimetry/differential thermal analysis and scanning electron microscopy studies
are carried out for the polymer electrolytes. The maximum ionic conductivity is found to be 4.511 × 10 −4 S cm −1 at 303 K for the plasticized polymer electrolyte with 8 wt.% of LiClO 4. The ionic conductivity is found to decrease with an increase of LiClO 4 concentration. 相似文献
7.
Ion-conducting thin film polymer electrolytes based on poly(ethylene oxide) (PEO) complexes with NaAlOSiO molecular sieves
powders has been prepared by solution casting technique. X-ray diffraction, scanning electron microscopy, differential scanning
calorimeter, and alternating current impedance techniques are employed to investigate the effect of NaAlOSiO molecular sieves
on the crystallization mechanism of PEO in composite polymer electrolyte. The experimental results show that NaAlOSiO powders
have great influence on the growth stage of PEO spherulites. PEO crystallization decrease and the amorphous region that the
lithium-ion transport is expanded by adding appropriate NaAlOSiO, which leads to drastic enhancement in the ionic conductivity
of the (PEO) 16LiClO 4 electrolyte. The ionic conductivity of (PEO) 16LiClO 4-12 wt.% NaAlOSiO achieves (2.370 ± 0.082) × 10 −4 S · cm −1 at room temperature (18 °C). Without NaAlOSiO, the ionic conductivity has only (8.382 ± 0.927) × 10 −6 S · cm −1, enhancing 2 orders of magnitude. Compared with inorganic oxide as filler, the addition of NaAlOSiO molecular sieves powders
can disperse homogeneously in the electrolyte matrix without forming any crystal phase and the growth stage of PEO spherulites
can be hindered more effectively. 相似文献
8.
Thin films of ZnSe and PEO–chitosan blend polymer doped with NH 4I and iodine crystals were prepared to form the two sides of a semiconductor electrolyte junction. ZnSe was electrodeposited
on indium tin oxide (ITO) conducting glass. The polymer is a blend of 50 wt% chitosan and 50 wt% polyethylene oxide. The polymer
blend was complexed with ammonium iodide (NH 4I), and some iodine crystals were added to the polymer–NH 4I solution to provide the I −/I 3−redox couple. The room temperature ionic conductivity of the polymer electrolyte is 4.32 × 10 −6 S/cm. The polymer film was sandwiched between the ZnSe semiconductor and an ITO glass to form a ZnSe/polymer electrolyte/ITO
photovoltaic cell. The open circuit voltage ( V
oc) of the fabricated cells ranges between 200 to 400 mV and the short circuit current between 7 to 10 μA. 相似文献
9.
A proton-conducting polymer electrolyte based on agar and ammonium nitrate (NH4NO3) has been prepared through solution casting technique. The prepared polymer electrolytes were characterized by impedance spectroscopy, X-ray diffraction, and Fourier transform infra-red spectroscopy. Impedance analysis shows that sample with 60 wt.% NH4NO3 has the highest ionic conductivity of 6.57 × 10−4 S cm−1 at room temperature. As a function of temperature, the ionic conductivity exhibits an Arrhenius behaviour increasing from 6.57 × 10−4 S cm−1 at room temperature to 1.09 × 10−3 S cm−1 at 70 °C. Transport parameters of the samples were calculated using Wagner’s polarization method and thus shows that the increase in conductivity is due to the increase in the number of mobile ions. Fuel cell has been constructed with the highest proton conductivity polymer 40agar/60NH4NO3 and the open circuit voltage is found to be 558 mV. 相似文献
10.
The effect of plasticizer and TiO 2 nanoparticles on the conductivity, chemical interaction and surface morphology of polymer electrolyte of MG49–EC–LiClO 4–TiO 2 has been investigated. The electrolyte films were successfully prepared by solution casting technique. The ceramic filler,
TiO 2, was synthesized in situ by sol-gel process and was added into the MG49–EC–LiClO 4 electrolyte system. Alternating current electrochemical impedance spectroscopy was employed to investigate the ionic conductivity
of the electrolyte films at 25 °C, and the analysis showed that the addition of TiO 2 filler and ethylene carbonate (EC) plasticizer has increased the ionic conductivity of the electrolyte up to its optimum
level. The highest conductivity of 1.1 × 10 −3 Scm −1 was obtained at 30 wt.% of EC. Fourier transform infrared spectroscopy measurement was employed to study the interactions
between lithium ions and oxygen atoms that occurred at carbonyl (C=O) and ether (C-O-C) groups. The scanning electron microscopy
micrograph shows that the electrolyte with 30 wt.% EC posses the smoothest surface for which the highest conductivity was
obtained. 相似文献
11.
In the present paper, the ionic conductivity and the dielectric relaxation properties on the poly(vinyl alcohol)-CF 3COONH 4 polymer system have been investigated by means of impedance spectroscopy measurements over wide ranges of frequencies and
temperatures. The electrolyte samples were prepared by solution casting technique. The temperature dependence of the sample’s
conductivity was modeled by Arrhenius and Vogel-Tammann-Fulcher (VTF) equations. The highest conductivity of the electrolyte
of 3.41×10 − 3 (Ωcm) − 1 was obtained at 423 K. For these polymer system two relaxation processes are revealed in the frequency range and temperature
interval of the measurements. One is the glass transition relaxation ( α-relaxation) of the amorphous region at about 353 K and the other is the relaxation associated with the crystalline region
at about 423 K. Dielectric relaxation has been studied using the complex electric modulus formalism. It has been observed
that the conductivity relaxation in this polymer system is highly non-exponential. From the electric modulus formalism, it
is concluded that the electrical relaxation mechanism is independent of temperature for the two relaxation processes, but
is dependent on composition. 相似文献
12.
The ZnO filler has been introduced into a solid polymeric electrolyte of polyvinyl chloride (PVC)–ZnO–LiClO 4, replacing costly organic filler for conductivity improvement. Ionic conductivity of PVC–ZnO–LiClO 4 as a function of ZnO concentration and temperature has been studied. The electrolyte samples were prepared by solution casting
technique. The ionic conductivity was measured using impedance spectroscopy technique. It was observed that the conductivity
of the electrolyte varies with ZnO concentration and temperature. The temperature dependence on the conductivity of electrolyte
was modelled by Arrhenius and Vogel–Tammann–Fulcher equations, respectively. The temperature dependence on the conductivity
does not fit in both models. The highest room temperature conductivity of the electrolyte of 3.7 × 10 −7 Scm −1 was obtained at 20% by weight of ZnO and that without ZnO filler was found to be 8.8 × 10 −10 Scm −1. The conductivity has been improved by 420 times when the ZnO filler was introduced into the PVC–LiClO 4 electrolyte system. It was also found that the glass transition temperature of the electrolyte PVC–ZnO–LiClO 4 is about the same as PVC–LiClO 4. The increase in conductivity of the electrolyte with the ZnO filler was explained in terms of its surface morphology. 相似文献
13.
Solid polymer electrolytes (SPE) based on poly-(vinyl alcohol) (PVA) 0.7 and sodium iodide (NaI) 0.3 complexed with sulfuric acid (SA) at different concentrations were prepared using solution casting technique. The structural
properties of these electrolyte films were examined by X-ray diffraction (XRD) studies. The XRD data revealed that sulfuric
acid disrupt the semi-crystalline nature of (PVA) 0.7(NaI) 0.3 and convert it into an amorphous phase. The proton conductivity and impedance of the electrolyte were studied with changing
sulfuric acid concentration from 0 to 5.1 mol/liter (M). The highest conductivity of (PVA) 0.7(NaI) 0.3 matrix at room temperature was 10 −5 S cm −1 and this increased to 10 −3 S cm −1 with doping by 5.1 M sulfuric acid. The electrical conductivity (σ) and dielectric permittivity ( ε′) of the solid polymer electrolyte in frequency range (500 Hz–1 MHz) and temperature range (300–400) K were carried out.
The electrolyte with the highest electrical conductivity was used in the fabrication of a sodium battery with the configuration
Na/SPE/MnO 2. The fabricated cells give open circuit voltage of 3.34 V and have an internal resistance of 4.5 kΩ. 相似文献
14.
A solid polymer electrolyte comprising blend of poly(ethylene oxide) and 50% epoxidized natural rubber (ENR50) as a polymer
host, LiCF 3SO 3 as a salt and nanoparticle ZnO as an inorganic filler was prepared by solution-casting technique. The effect of filler on
the electrolyte properties was characterized and analysed. FESEM analysis showed that the filler was well distributed in the
polymer matrix, while the effective interaction between the salt and the polymer host was reduced by the addition of filler.
As evidenced by FTIR analysis, which showed the formation of triplet peak at C-O-C stretching region. Ionic conductivity was
found to decrease from 1.4 × 10 −4 Scm −1 to 2.5 × 10 −6 Scm −1 upon the addition of filler, due to the blocking effect of filler into the electrolyte conduction pathways. The temperature
dependence on the electrolyte conductivity obeys Arrhenius rule in two temperature regions. 相似文献
15.
The blend-based polymer electrolyte consisting of poly (vinyl chloride) (PVC) and poly (ethylene glycol) (PEG) as host polymers
and lithium perchlorate (LiClO 4) as the complexing salt was studied. An attempt was made to investigate the effect of TiO 2 concentration in the unplasticized PVC–PEG polymer electrolyte system. The XRD and FTIR studies confirm the formation of
a polymer–salt complex. The conductivity results indicate that the incorporation of ceramic filler up to a certain concentration
(15 wt.%) increases the ionic conductivity and upon further addition the conductivity decreases. The maximum ionic conductivity
0.012 × 10 −4 S cm −1 is obtained for PVC–PEG–LiClO 4–TiO 2 (75–25–5–15) system. Thermal stability of the polymer electrolyte is ascertained from TG/DTA studies. 相似文献
16.
A polymer blend electrolyte based on polyvinyl alcohol (PVA) and polyacrylonitrile (PAN) was prepared by a simple solvent casting technique in different compositions. The ionic conductivity of polymer blend electrolytes was investigated by varying the PAN content in the PVA matrix. The ionic conductivity of polymer blend electrolyte increased with the increase of PAN content. The effect of lithium salt concentrations was also studied for the polymer blend electrolyte of high ionic conductivity system. A maximum ionic conductivity of 3.76×10 −3 S/cm was obtained in 3 M LiClO 4 electrolyte solution. The effect of ionic conductivity of polymer blend electrolyte was measured by varying the temperature ranging from 298 to 353 K. Linear sweep voltammetry and DC polarization studies were carried out to find out the stability and lithium transference number of the polymer blend electrolyte. Finally, a prototype cell was assembled with graphite as anode, LiMn 2O 4 as cathode, and polymer blend electrolyte as the electrolyte as well as separator, which showed good compatibility and electrochemical stability up to 4.7 V. 相似文献
17.
Polymer electrolyte based on PVA doped with different concentrations of NH 4Br has been prepared by solution casting technique. The complexation of the prepared polymer electrolytes has been studied using X-ray diffraction (XRD) and Fourier transform infra red (FTIR) spectroscopy. The maximum ionic conductivity (5.7×10 −4 S cm −1) has been obtained for 25 mol% NH 4Br-doped PVA polymer electrolyte. The temperature dependence of ionic conductivity of the prepared polymer electrolytes obeys Arrhenius law. The ionic transference number of mobile ions has been estimated by dc polarization method and the results reveal that the conducting species are predominantly ions. The dielectric behavior of the polymer electrolytes has been analyzed using dielectric permittivity and electric modulus spectra. 相似文献
18.
Plasticized polymer electrolytes composed of poly(methyl methacrylate) (PMMA) as the host polymer and lithium bis(trifluoromethanesulfonyl)imide
LiN(CF 3SO 2) 2 as a salt were prepared by solution casting technique at different ratios. The ionic conductivity varied slightly and exhibited
a maximum value of 3.65 × 10 −5 S cm −1 at 85% PMMA and 15% LiN(CF 3SO 2) 2. The complexation effect of salt was investigated using FTIR. It showed some simple overlapping and shift in peaks between
PMMA and LiN(CF 3SO 2) 2 salt in the polymer electrolyte. Ethylene carbonate (EC) and propylene carbonate (PC) were added to the PMMA–LiN(CF 3SO 2) 2 polymer electrolyte as plasticizer to enhance the conductivity. The highest conductivities obtained were 1.28 × 10 −4 S cm −1 and 2.00 × 10 −4 S cm −1 for EC and PC mixture system, respectively. In addition, to improve the handling of films, 1% to 5% fumed silica was added
to the PMMA–LiN(CF 3SO 2) 2–EC–PC solid polymer electrolyte which showed a maximum value at 6.11 × 10 −5 S cm −1 for 2% SiO 2. 相似文献
19.
An attempt has been made to prepare a new proton-conducting polymer electrolyte based on poly(vinyl alcohol) doped with ammonium fluoride (NH 4F) by solution casting technique. The complex formation between polymer and dissociated salt has been confirmed by X-ray diffraction and Fourier transform infrared spectroscopy studies. The highest ionic conductivity has been found to be 6.9?×?10 ?6?Scm ?1 at ambient temperature (303 K) for 85PVA:15NH 4F polymer electrolyte. The conductance spectra contain a low frequency plateau region and high frequency dispersion region. The dielectric spectra exhibit the low frequency dispersion, which is due to space charge accumulation at the electrode–electrolyte interface. The modulus spectra indicate non-Debye nature of the material. The highest ionic conductivity polymer electrolyte 85PVA:15NH 4F has low activation energy 0.2 eV among the prepared polymer electrolytes. 相似文献
20.
The conducting polymer electrolyte films consisting of polyacrylonitrile (PAN) as the host polymer, lithium triflate (LiCF 3SO 3) and sodium triflate (NaCF 3SO 3) as inorganic salts were prepared by the solution-cast technique. The pure PAN film was prepared as a reference. The ionic
conductivity for the films is characterized using impedance spectroscopy. The room temperature conductivity for the PAN + 26 wt.%
LiCF 3SO 3 film and the PAN + 24 wt.% NaCF 3SO 3 film is 3.04 × 10 −4 S cm −1 and 7.13 × 10 −4 S cm −1, respectively. XRD studies show that the complexation that has occurred in the PAN containing salt films and complexes formed
are amorphous. The FTIR spectra results confirmed the complexation has taken place between the salt and the polymer. These
results correspond with surface morphology images obtained from SEM analysis. The conductivity–temperature dependence of the
highest conducting film from PAN + LiCF 3SO 3 and PAN + NaCF 3SO 3 systems follows Arrhenius equation in the temperature range of 303 to 353 K. The PAN containing 24 wt.% LiCF 3SO 3 film has a higher ionic conductivity and lower activation energy compared to the PAN containing 26 wt.%LiCF 3SO 3 film. These results can be explained based on the Lewis acidity of the alkali ions, i.e., the interaction between Li + ion and the nitrogen atom of PAN is stronger than that of Na + ion. 相似文献
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