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1.
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)16LiClO4 electrolyte. The ionic conductivity of (PEO)16LiClO4-12 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
2.
In the paper the dependence of the photorefraction (PhR) in LiNbO3 and LiNbO3−Fe (0.1 wt%, 0.3wt%) crystals on light intensity (within 1016–1023 quanta·cm−2·s−1 at wavelengths 496.5 nm and 600 nm) and temperature (in the region 100–500 K) is studied. For all the crystals the limiting
values of PhR are similar and atT=293 K Δn
sat
lim
≈3·10−3. In LiNbO3 the temperature dependence of PhR in the range 100–500 K requires to take into account at least two trapping centres. 相似文献
3.
The present paper deals with ion transport studies on a new proton conducting composite polymer electrolyte — (PVAx:NH4SCN)y:PVAc system. Complexation and morphology of the composite electrolyte films are discussed on the basis of X-ray diffraction
and differential scanning calorimetry data. Coulometry and transient ionic current measurements revealed charge transport
through protons. The maximum ion conductivity was found to be 7.4·10−4 S·cm−1 for the composition: x=0.15, y=0.12. The observed conductivity behaviour is correlated to the morphology of the films. The
temperature dependence of the electrical conductivity exhibits Arrhenius characteristics in two different temperature ranges
separated by a plateau region related to morphological changes occurring in the electrolyte. 相似文献
4.
Non-aqueous polymer gel electrolytes containing trifluoromethanesulfonic acid (HCF3SO3) and polyethylene oxide (PEO) as the gelling polymer has been studied. The increase in conductivity observed with the addition
of PEO to liquid electrolytes has been explained to be due to the breaking of ion aggregates present in electrolytes at higher
acid concentrations. The increase in free H+ ion concentration upon breaking of ion aggregates has also been observed in pH measurements and viscosity of gel electrolytes
has been found to increase with PEO addition. Polymer gel electrolytes containing dimethylacetamide (DMA) have σ ∼ 10−2 S/cm at room temperature and are stable over −50 to 125 °C range of temperature. Gels based on propylene carbonate (PC) and
ethylene carbonate (EC) are stable in the −50 to 40 °C temperature range and loose their gelling nature above 40 °C. 相似文献
5.
Non-aqueous polymer gel electrolytes containing trifluoromethanesulfonic acid (HCF3SO3) and polyethylene oxide (PEO) as the gelling polymer has been studied. The increase in conductivity observed with the addition
of PEO to liquid electrolytes has been explained to be due to the breaking of ion aggregates present in electrolytes at higher
acid concentrations. The increase in free H+ ion concentration upon breaking of ion aggregates has also been observed in pH measurements and viscosity of gel electrolytes
has been found to increase with PEO addition. Polymer gel electrolytes containing dimethylacetamide (DMA) have σ ∼ 10−2 S/cm at room temperature and are stable over −50 to 125 °C range of temperature. Gels based on propylene carbonate (PC) and
ethylene carbonate (EC) are stable in the −50 to 40 °C temperature range and loose their gelling nature above 40 °C. 相似文献
6.
The conductivity of poly(N-vinylimidazole) (PVIM) and its fluoroborate salt (PVIM–HBF4) are reported here. N-vinylimidazole is polymerized by free radical method and PVIM–HBF4 is prepared by acidification of PVIM with HBF4. The polyelectrolyte so formed has been characterized by infrared, hydrogen-1 nuclear magnetic resonance, thermogravimetric
analyzer, and differential scanning calorimetry. Frequency and temperature dependence of AC conductivity has been studied
to learn about the electrical conduction behavior in the materials. The electrical conductivity of the new material is found
to be in the range of 10−5 to 10−6 S cm−1.There is about 102- to 103-fold increase in conductivity of the polyelectrolyte. The material is shown to be a predominantly ionic conductor with t
ion ≈ 0.88. Apparent activation energies are found to be 0.397 and 0.250 eV for the polymer and the polyelectrolyte, respectively. 相似文献
7.
A sodium ion conducting composite polymer electrolyte (CPE) prepared by solution-caste technique by dispersion of an electrochemically
inert ceramic filler (SnO2) in the PEO–salt complex matrix is reported. The effect of filler concentration on morphological, electrical, electrochemical,
and mechanical stability of the CPE films has been investigated and analyzed. Composite nature of the films has been confirmed
from X-ray diffraction and scanning electron microscopy patterns. Room temperature d.c. conductivity observed as a function
of filler concentration indicates an enhancement (maximum) at 1–2 wt% filler concentration followed by another maximum at
∼10 wt% SnO2. This two-maxima feature of electrical conductivity as a function of filler concentration remains unaltered in the CPE films
even at 100 °C (i.e., after crystalline melting), suggesting an active role of the filler particles in governing electrical
transport. Substantial enhancement in the voltage stability and mechanical properties of the CPE films has been noticed on
filler dispersion. The composite polymer films have been observed to be predominantly ionic in nature with t
ion ∼ 0.99 for 1–2 wt% SnO2. However, this value gets lowered on increasing addition of SnO2 with t
ion ∼ 0.90 for 25 wt% SnO2. A calculation of ionic and electronic conductivity for 25 wt% of SnO2 film works out to be ∼2.34 × 10−6 and 2.6 × 10−7 S/cm, respectively. 相似文献
8.
Composite materials used for electrode and electrolyte materials have been intensely studied in view of their advantages such
as higher conductivity and better operational performance compared to their single-phase counterparts. The present work aims
at studying the electrical and structural characteristics of a new composite electrolyte namely, (PbI2)
x
− (Ag2O–Cr2O3)100−x
where x = 5, 10, 15, 20, and 25 mol%, respectively, prepared by the melt quenching technique. The room temperature X-ray diffraction
spectra revealed certain crystalline phases in the samples. AC conductivity analysis for all the prepared samples was carried
out over the frequency range 1 MHz–20 Hz and in the temperature window 297–468 K. The room temperature conductivity values
were calculated to be in the order of 10−5–10−3 Scm−1. An Arrhenius dependence of temperature with conductivity was observed, and the activation energies calculated were found
to be in the range 0.27–0.31 eV. Furthermore, the total ionic transport number (t
i) values obtained for all these indicated the ionic nature of this system.
Paper presented at the Third International Conference on Ionic Devices (ICID 2006), Chennai, Tamilnadu, India, Dec. 7–9, 2006. 相似文献
9.
Markin G. V. Baranov E. V. Ketkov S. Yu. Lopatin M. A. Kuropatov V. A. Shavyrin A. S. Domrachev G. A. 《Physics of the Solid State》2012,54(3):647-651
For the first time, bis(anisole)chromium fulleride (PhOMe)2Cr+·[C60]−· and a crystalline complex of fullerene with ortho-butoxyanisole have been obtained. The temperature dependence of the parameters
of the EPR spectrum of bis(anisole)chromium fulleride (PhOMe)2Cr+·[C60]−· has been studied. The molecular structure of the complex of fullerene with ortho-butoxyanisole has been established. 相似文献
10.
A new ion conducting solid polymer electrolyte thin film based on Polyethylene oxide (PEO) with NaClO3 salt is prepared by solution-casting method. The solvation of salt with PEO has been confirmed by X-ray diffraction and IR
spectral studies. Plasticizer effects were studied in PEO:NaClO3 system by using low molecular weight polyethylene glycol (PEG), dimethyl formamide (DMF) and propylene carbonate(PC). AC
conductivity in the temperature range (308–378 K) was measured to evaluate the conductivity of the polymer electrolytes. From
the conductivity data, it was found that the conductivity value of pure PEO increases 102–104 order of magnitude with the addition of salts as well as plasticizers. From the transference number experiments, it was confirmed
that the charge transport in these electrolyte is mainly due to the ions (tion≈0.94). Finally, the conductivity value of all PEO: NaClO3 systems were compared. 相似文献
11.
Poly (vinylchloride) (PVC)-LiBF4 polymer electrolytes plasticized with DBP in different mole ratios have been studied by FTIR and Impedance Spectroscopic
techniques. The complexation has been confirmed from FTIR studies. The maximum room temperature conductivity (2.1·.10−7 S·.cm−1) has been observed for PVC-LiBF4-DBP (10-5-85 mole%) complex. The temperature dependence of the conductivity of the polymer films seems to obey the VTF relation.
The conductivity values are presented and the results are discussed. 相似文献
12.
Doubly substitution of vanadium by Cu and Co in the limit of 10% in Bi4V2O11, has led to the formation of the Bi4V1.8Cu0.2−xCoxO10.7 solid solution. X-ray diffraction shows that all the compositions present a tetragonal symmetry. The thermal analysis has
revealed that the polymorph γ' phase, which is formed by a partial ordering of oxygen ions in the γ high temperature form,
is stabilized at room temperature. The influence of sintering temperature on the microstructure of the samples was investigated
by the scanning electron microscopy (SEM). The ceramics sintered at 820 °C for more than 3 hours present micro-craks. The
evolution of the electrical conductivity with temperature and the degree of substitution has been investigated by impedance
spectroscopy. The sample with x=0.1 presents the highest value of the conductivity ≈4.6×10−2 S·cm−1 at 600 °C. 相似文献
13.
Kamlesh Pandey Mrigank Mauli Dwivedi Mridula Tripathi Markandey Singh S. L. Agrawal 《Ionics》2008,14(6):515-523
Development and characterisation of polyethylene oxide (PEO)-based nanocomposite polymer electrolytes comprising of (PEO-SiO2): NH4SCN is reported. For synthesis of the said electrolyte, polyethylene oxide has been taken as polymer host and NH4SCN 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
14.
Pellicular γ-zirconium phosphate (γ-ZP(p)), i.e. sheets made up entirely of oriented lamellae of Zr(PO4)(H2PO4)·2H2O (γ-ZP), have been obtained by filtering colloidal dispersions of exfoliated γ-ZP in water/acetone. The ac-conductivity of
γ-ZP(p) and γ-ZP was measured in the temperature range 20/–20°C on samples previously conditioned at relative humidities between
90 and 5%. In both cases, the conductivity dependence on material hydration indicates the presence of a non-negligible bulk
transport at low relative humidities. For each relative humidity the conductivity data have been parameterised on the basis
of the Arrhenius equation. Activation energy and pre-exponential factor values suggest the presence of the same conduction
mechanism in both materials. The conductivity of γ-ZP(p) measured by applying the electric field parallel to the sheets ranges from 3·10−4 to 1·10−5 S cm−1 for relative humidity decreasing from 90 to 11%, being an order of magnitude higher than that of γ-ZP. Since the pellicular
and microcrystalline material have very similar surface areas (11–12 m2/g), the higher conductivity of γ-ZP(p) is mainly due to the preferred particle orientation parallel to the electric field.
Paper presented at the 3rd Euroconference on Solid State Ionics, Teulada, Sardinia, Italy, Sept. 15–22, 1996 相似文献
15.
H. Hoffmann J. Pickl M. Schmidt D. Krause 《Applied Physics A: Materials Science & Processing》1978,16(3):239-246
Indium oxide films doped with tin (ITO-films) have been hf-sputtered from an 80 at-%In2O3/20 at-%SnO2 target onto glass substrates. The sputter atmosphere contained mainly argon (10−2Torr) with addition of oxygen (0≦p
O
2≦2·10−2Torr). The sputtered films aren-conductors. The conductivity and density of charge carriers depend on the oxygen content of the sputter gas. They could be
varied by two orders of magnitude. In air or in oxygen atmosphere the films oxidize at the surface and for a certain depth
beneath the surface, thus decreasing the conductivity. The Hall mobility of the sputtered films is smaller (≈10 cm2V−1 s−1) than one observes at ITO films produced by CVD sparaying or other methods. The conductivity of as sputtered films approached
maximum values of about 1000Ώ−1cm−1. 相似文献
16.
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 (NH4SCN) in dimethyl sulphoxide (DMSO) and electrically characterized. The ionic conductivity measurements indicate that PEG:PVA:NH4SCN-based composite gel electrolytes are superior (σ
max = 5.7 × 10−2 S cm−1) to pristine electrolytes (PEG:NH4SCN system) and conductivity variation with filler concentration remains within an order of magnitude. The observed conductivity
maxima have been correlated to PEG:PVA:NH4SCN-and PVA:NH4SCN-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
17.
Solid polymer electrolyte films based on poly (ethylene oxide) PEO complexed with NaClO3 have been prepared by a solution-cast technique. The solvation of Na+ ion with PEO is confirmed by XRD and IR studies. Measurements of the a.c. conductivity in the temperature range 308 – 378
K and the transference numbers have been carried out to investigate the charge transport in this polymer electrolyte system.
Transport number data show that the charge transport in this polymer electrolyte system is predominantly due to ions. The
highest conductivity (2.12.10−4 S/cm) has been observed for the 70:30 composition. Using the polymer electrolyte solid state electrochemical cells have been
fabricated. The various cell parameters are evaluated and reported. 相似文献
18.
Lithium fast ion conductors of the composition Li0.3La2/3Ti0.7P0.3−xVxO3.3 (LTV) based on mixtures of Li3xLa2/3−xTiO3 and LaPO4 were prepared by solid state reaction at high temperature (≈ 1300 °C). AC impedance measurements indicate total conductivities
of about 1 × 10−4 Scm−1 for compositions of x=0∼0.3 at room temperature with an activation energy of ≈18 kJ·mol−1 in the temperature range from 30 to 400 °C. X-ray powder diffraction patterns showed that the LTV system is composed of Li3xLa2/3−xTiO3 perovskite solid solution and LaP1−xVxO4 solid solution. 相似文献
19.
L. Palladino A. Reale G. Taglieri D. Batani S. Bollanti P. Di Lazzaro F. Flora T. Letardi G. Schina M. Belli A. Scafati 《Il Nuovo Cimento D》1993,15(8):1133-1146
Summary We present a detailed study of XUV and soft X-ray emission from Cu plasma produced by an excimer laser at intensitiesI
L≦8·1011 W/cm2. The XeCl excimer laser (ψ≈308 nm) delivers pulses with energyE
L≈2.3 J, temporal durationt
L≈100 ns and brightnessB≧1014 W/cm2 sr. We recorded a spectral conversion efficiency η=0.5% eV−1 forI
L=4·1011W/cm2 in the aluminium window at 73eV with a harder X-ray tail around ≈400eV. We also measured the dependence of X-ray signal on
laser intensity and viewing angle. Experimental results have been compared with some analytical laser-plasma interaction models. 相似文献
20.
Filler-matrix thermal boundary resistance of diamond-copper composite with high thermal conductivity 总被引:1,自引:0,他引:1
A composite material with a high thermal conductivity is obtained by capillary infiltration of copper into a bed of diamond
particles of 400 μm size, the particles having been pre-coated with tungsten. The measured thermal conductivity of the composite
decreases from 910 to 480 W m−1 K−1 when the coating thickness is increased from 110 to 470 nm. Calculations of the filler/matrix thermal boundary resistance
R and the thermal conductivity of the coating layer λ
i
using differential effective medium, Lichtenecker’s and Hashin’s models give similar numerical values of R and λ
i
≈ 1.5 W m−1 K−1. The minimal thickness of the coating h ∼ 100 nm necessary for ensuring production of a composite while maximizing its thermal conductivity, is of the same order
as the free path of the heat carriers in diamond (phonons) and in copper (electrons). The heat conductance of the diamond/tungsten
carbide coating/copper interface when h is of this thickness is estimated as (0.8–1) × 108 W m−2 K−1 and is at the upper level of values characteristic for perfect dielectric/metal boundaries. 相似文献