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1.
The effect of plasticizer and TiO2 nanoparticles on the conductivity, chemical interaction and surface morphology of polymer electrolyte of MG49–EC–LiClO4–TiO2 has been investigated. The electrolyte films were successfully prepared by solution casting technique. The ceramic filler,
TiO2, was synthesized in situ by sol-gel process and was added into the MG49–EC–LiClO4 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 TiO2 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
2.
Mixed potential solid electrolyte CO sensors with sensing electrodes based on composite with various semiconducting oxides
were extensively studied in the temperature range 500–650 °C for sensitivity, stability and cross-sensitivity besides CO to
other combustion components like CO2, H2O, O2, and SO2. The highest CO sensitivity was found for the CO sensor with composite electrode based on Au/Ga2O3 showing also good reproducibility and stability in hazardous combustion environment. CO sensor response behavior in non equilibrated
oxygen containing gas mixtures is mainly determined by the catalytic activity of the measuring electrode and depends strongly
on preparation and measuring conditions. Mixed oxides based on doped chromites show only a little sensitivity to CO. CO sensor
based on Au/Ga2O3 composite electrodes was showing good CO selectivity in the presence of other combustion gas species and finally was tested
in combustion environment at power plant.
Paper presented at the 11th EuroConference on the Science and Technology of Ionics, Batz-sur-Mer, Sept. 9–15, 2007. 相似文献
3.
Composite electrolytes of Ag2SO4 is prepared by dispersing fine particles, average particle size <40 microns (350 mesh), of ferroelectric AgNbO3 in varying weight fraction. Enhancement in the conductivity is observed in β-phase of host system. The effect of dispersion
on the conductivity, activation energy and transition temperature is studied as a function of weight % of the dispersoid in
the host. Two distinct conduction mechanisms, viz. conduction through electrolyte bulk in parallel with conduction along the
inter-grain interaction layer (R
b
‖
‖R∞) and perpendicular to the interface (R
b
⊥
) could be resolved in the frequency range of 5 Hz to 13 MHz at temperatures below 300 °C. The interface interaction is found
to be nucleophilic increasing the concentration of Ag+ vacancies at the interface. Potentiometric SO2 gas sensors are tested with this composite electrolyte as an auxiliary phase.
Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003. 相似文献
4.
In thick film gas sensors Nasicon is used as a solid electrolyte with high Na+ ionic conductivity. Sensors like CO2, O2, Pt ▮ Na2CO3, BaCO3 ∥ NASICON [Pt]glass, O2, CO2 are suitable to measure the CO2-concentration over 5 orders of magnitude. To characterize the screen printed Nasicon as a main component of such sensors
grazing incidence diffractometry (GID), SEM, impedance spectroscopy and dc polarization measurements are performed in order
to improve the long-term stability. The sintering process of the thick film influences the chemical surface composition of
Nasicon and as a consequence the response of the sensor. Nasicon films sintered at temperatures between 1070 and 1210 °C show
an amorphous layer increasing up to 1.1 μm thickness on the surface. Impedance measurements show, that cells using in such
a way prearated Nasicon are responsible for water vapour.
Paper presented at the 1st Euroconference on Solid State Ionics, Zakynthos, Greece, 11 – 18 Sept. 1994 相似文献
5.
Li2SnO3 has been synthesized at 1000 °C from Li2CO3 and SnO2 (high temperature form - HT) and it has also been prepared from ball-milled SnO2 and Li2CO3 at 650 °C (low temperature form - LT). The Li2SnO3 materials have been tested as a negative electrode for possible use in a Li-ion cell and their electrochemical behaviour
has been compared with that of SnO2. In theory, Li2SnO3 and SnO2 should be able to cycle the same number of lithium atoms per tin atom but on the initial discharge SnO2 has inserted more lithium than Li2SnO3. During the initial discharge of SnO2 and Li2SnO3, a side electrochemical reaction seems to be occurring. The resultant compound apparently inserts lithium reversibly for
potentials around 1 V; however, cycling from 0.02–2 V significantly degrades performance compared to 0.02–1 V. Li2SnO3 (HT) allows the de-insertion of more lithium than Li2SnO3 (LT) and SnO2 in the first charge.
Paper presented at the 7th Euroconference on Ionics, Calcatoggio, Corsica, France, Oct. 1–7, 2000. 相似文献
6.
Potentiometric CO2 gas sensors with Li conducting glasses/glass ceramics of the system Li2O-Al2O3-SiO2 (different nominal composition) as solid electrolytes have been investigated. Li2CO3 was used as CO2 and O2 sensitive auxiliary electrode. During the sensor test measurements, the CO2 partial pressure was varied between 1×10−3 and 1×10−1 bar at a constant O2 partial pressure of 2.1×10−1 bar whereas N2 was used as carrier gas. Comparative measurements were accomplished with sensors comprising Na and K ion conducting glasses.
A metastable reference electrode was formed at the contact zone between the Au metal electrode and the former Li glasses of
definite nominal composition by crystallization processes taking place, which lead to stable, reproducible CO2 dependent EMF signals for more than 90d. The thermodynamically expected EMF difference and the observed EMF difference agree
quite well between 500 and 600 °C.
At 600 °C, the drift of sensors with glasses as solid electrolytes and direct Au glass/glass ceramics contact as reference
electrode amounts typically 0.32 mV/d (p(CO2)=1×10−3 bar, p(O2)=2.1×10−1 bar at the measuring electrode), if a metastable multiphase equilibrium is formed. At identical partial pressures of CO2 and O2, the signal reproducibility of these sensors with different solid electrolyte glasses of the same nominal composition lies
within 30 mV at 600 °C.
Paper presented at the 3rd Euroconference on Solid State Ionics, Teulada, Sardinia, Italy, Sept. 15–22, 1996 相似文献
7.
Potentiometric CO2 gas sensors with thin-film lithium phosphate (Li3PO4) electrolytes were developed by using radio frequency (RF) magnetron sputtering. Li2CO3 and a mixture of Li2TiO3 and TiO2 were used as sensing and reference electrodes, respectively. By using the RF sputtering deposition process, we obtained a dense, crystalline, thin-film Li3PO4 electrolyte with good adhesion on the Al2O3 substrate. The thin-film Li3PO4 electrolyte had good ionic conductivity, i.e., 2.15?×?10?6 S cm?1 at 500 °C, and its activation energy was 0.97 eV. The thin-film Li3PO4 electrolyte was suitable for the miniaturization of potentiometric CO2 sensors. The thin-film potentiometric CO2 sensor provided relatively good sensing response for overall CO2 concentrations (500 to 3,000 ppm and 5 to 20 %) at 500 °C. The Nernstian slope of 78.2 mV/decade obtained for CO2 concentrations from 5 to 20 % at 500 °C was close to the theoretical value (76.6 mV/decade). Although the sensor’s reading deviated from the theoretical value at low CO2 concentrations (500 to 3,000 ppm), the sensor provided better sensing performance than a potentiometric CO2 sensor with a thick electrolyte. As a result, it was assumed that the thin-film sensor could be used to monitor the overall concentration of CO2 in the environment. 相似文献
8.
Hiroyuki Nakano Kaoru Dokko Masanori Hara Yasuhiro Isshiki Kiyoshi Kanamura 《Ionics》2008,14(2):173-177
A novel electrode system composed of three-dimensionally ordered macroporous (3DOM) Li1.5Al0.5Ti1.5(PO4)3 (LATP) and LiMn2O4 was fabricated by the colloidal crystal templating method and sol–gel process. A LATP nanoparticle for the fabrication of
3DOM-LATP was prepared by a sol–gel process. A suspension containing polystyrene (PS) beads and the LATP nanoparticles was
filtrated by using a polycarbonate filter to accumulate PS beads and LATP. The accumulated PS beads had a close-packing structure,
and the void between PS beads was filled with LATP nanoparticles. 3DOM-LATP was obtained by heat treatment of the accumulated
composite. Li–Mn–O sol was injected by a vacuum impregnation process into the macropores of 3DOM-LATP and then was heated
to form three-dimensionally ordered composite materials consisting of LiMn2O4 and LATP. The formation of the composite between 3DOM-LATP and LiMn2O4 were confirmed with scanning electron microscopy and X-ray diffraction method. The prepared composite electrode system exhibited
a good electrochemical performance.
Paper presented at the 11th EuroConference on the Science and Technology of Ionics, Batz-sur-Mer, Sept. 9–15, 2007. 相似文献
9.
Co-sintering of Cu-CGO cermet anodes on CGO (Ce0.8Gd0.2O2−δ) electrolyte was conducted at low temperature (1000 °C) by introducing small amounts (2 mol.%) of CuO sintering aid to the
electrolytic CGO. The Cu-CGO anodes with Cu contents from 20–50 vol.% were prepared by combustion synthesis followed by sintering
and reduction. Symmetrical anode/electrolyte/anode assemblies of Cu-GCO/CGO/Cu-CGO were fabricated by manually depositing
the anode combustion powder on a green substrate of the 2 mol% CuO-containing CGO, followed by co-pressing and co-sintering
of the assembly at 1000 °C. The low-temperature sintered CGO is submicron with 95–99% relative density. CuO addition has no
significant effect on either the total or ionic conductivity of the electrolyte, but p-type conduction in the temperature
range, 900–1200 °C, is 25 times higher than that of undoped CGO. Oxygen-ion transference numbers of the Cu-containing CGO
lie in the range 0.89–0.99, as determined by the modified e.m.f. technique under an oxygen/air potential gradient. The activation
energy for ionic conduction, 83 kJmol−1, is significantly lower than that for p-type electronic transport, 140 kJmol−1.
Paper presented at the 9th EuroConference on Ionics, Ixia, Rhodes, Greece, Sept. 15 – 21, 2002. 相似文献
10.
Liwei Su Linhui Liu Jinpei Hei Huan Chen Lianbang Wang Yuanhao Wang Manman Ren 《Particle & Particle Systems Characterization》2020,37(8):2000164
V2O5, as a lithium-free cathode material, has inherent defects such as sluggish kinetics and volume change and, at the same time, requires a lithium metal anode that tends to form dendrites in liquid electrolytes. Both the lithium dendrite and the flammable electrolyte solvent bring longtime safety issues. This work introduces nonflammable inorganic–organic composite solid electrolyte to inhibit the growth of the lithium dendrite and suppress the instability caused by V2O5 nanometerization. However, the long-term cycling and rate performances are still insufficient even when reducing V2O5 size to about 50 nm. As an improvement, sub-10 nm V2O5/C nanosheets are designed and prepared using corn stalks as precursors through simple impregnation and calcination process. The V2O5/C offers a much better electrode/electrolyte contact and interface stability than bulk V2O5 and commercial V2O5 in the inorganic–organic composite solid electrolyte. The discharge capacity is 228 mAh g−1 at 0.1 C after 50 cycles and ≈110 mAh g−1 at 2.0 C. 相似文献
11.
The recent interest in the (Sr, Mg) doped LaGaO3 family compounds as electrolyte for Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFCs) has suggested the study of
the system α-Al2O3/La0.8Sr0.2Ga0.8Mg0.2O3–δ as a possible new ionic conductor composite. The studies concerning the electrical and microstructural characterization of
the system α-Al2O3/La0.8Sr0.2Ga0.8Mg0.2O3–δ, in a wide compositions range, are reported and discussed.
Paper presented at the Patras Conference on Solid State Ionics — Transport Properties, Patras, Greece, Sept. 14 – 18, 2004. 相似文献
12.
G. B. Appetecchi F. Croce F. Ronci B. Scrosati F. Alessandrini M. Carewska P. P. Prosini 《Ionics》1999,5(1-2):59-63
In the development of rechargeable lithium polymer batteries it is of paramount importance to control the passivation phenomena
occurring at the lithium electrode interface. It is well estabilished that the type and the growth of the lithium passivation
layer is unpredictably influenced by the presence of liquid components and/or impurities in the electrolyte. Therefore, one
approach to improve the stability of the lithium interface is the use of liquid-free, highly pure electrolytes.
The electrochemical properties of a composite polymer electrolyte obtained by hot pressing a mixture of polyethylene oxide
(PEO), a lithium salt (lithium tetrafluoroborate, LiBF4) and a powdered ceramic additive (γ-LiAlO2), will be presented and discussed.
The electrochemical characterization included the determination of the ionic conductivity, the anodic break-down voltage and,
most importantly, the stability of the lithium metal electrode interface and the lithium stripping-plating process efficiency.
The main feature of this dry, true solid-state electrolyte is a very good compatibility with the lithium metal electrode,
demonstrated by a very high lithium cycling efficiency, which approaches a value of 99%.
Paper presented at the 5th Euroconference on Solid State Ionics, Benalmádena, Spain, Sept. 13–20, 1998. 相似文献
13.
Alkali-ion conducting glasses/glass ceramics of the system Me2O-A12O3-SiO2 (Me=Li, Na) were applied as solid electrolytes in potentiometric gas sensors to detect CO2 in the presence of O2 at increased temperatures. The corresponding Me-Carbonates were utilized as auxiliary electrodes. Sensors using the direct
Au-glass contact as a kind of reference electrode (type I), as well as symmetrical sensors with carbonate phase at the reference
and measuring electrode (type II - for comparative measurements) were manufactured.
By applying Au as electrode metal, the theoretically expected EMF difference and the observed EMF difference of both sensor
types agree quite well with the expected values according to the Nernst equation between 500 and 600 °C (over four orders
of magnitude of CO2 partial pressure (10−5 – 10−1 bar) at constant O2 partial pressure (2.1×10−1 bar)). A long time stability of 120 days for sensors of type I with Li glasses has been observed, although evaporation of
carbonate phase (Li2CO3) was detected under the conditions of sensor application. Sensors of type I (with Li2CO3) show thermodynamically unexpected cross-sensitivities to H2O.
Paper presented at the 3rd Euroconference on Solid State Ionics, Teulada, Sardinia, Italy, Sept. 15–22, 1996 相似文献
14.
Lithiated transition metal oxides having a layered structure and general formula LiMO2, have been extensively studied as positive electrode active materials for lithium or lithium-ion batteries. In particular,
lithium nickel dioxide (LiNiO2) and lithium cobalt dioxide (LiCoO2) present a layered structure with high diffusion coefficients for the lithium ion. This latter property is very important
in order to realize practical devices having high discharge rates. LiNiO2, compared with LiCoO2, has the advantage to be a cheaper material with a higher specific capacity for lithium cycling, but its stability upon cycling
can be greatly influenced by the displacement of Ni ions from the Ni layers to the Li planes as the content in lithium is
reduced over a certain value. Recently, solid solutions such as LiNixCo1−xO2 have been proposed to offer a compromise between stability, cost and capacity.
In this work we have studied LiNi0.5Co0.5O2 prepared by the Complex Sol-Gel Process (CSGP). The advantage of this procedure toward the solid-state process is the high
homogeneity in composition and in particle dimension of the synthesized compounds. The samples have been characterized electrochemically
using chronopotentiometric, voltammetric and impedance measurements in liquid electrolyte. The results indicates that CSGP-synthesized
LiNi0.5Co0.5O2 shows good cyclability (after 1000 cycles about 2/3 of the initial capacity can still be cycled) only if the anodic potential
is limited to about 4.2 V. The quite low values of the specific capacity (∼70 mAh/g at C/1 charge-discharge rate) can be justified
by the non-complete calcination reaction, as suggested by X-ray measurements. Kinetic properties have been evaluated by Electrochemical
Impedance Spectroscopy measurements, which have shown quite high values for the lithium chemical diffusion coefficient (10−7÷10−8 cm2s−1) and its unexpected decrease as deintercalation proceeds from x=0.5 in LiNi0.5Co0.5O2.
Paper presented at the 4th Euroconference on Solid State Ionics, Renvyle, Galway, Ireland, Sept. 13–19, 1997 相似文献
15.
The development of a solid state thin film lithium battery system needs a detailed investigation of the electrolyte as well
as the electrodes. The realisation of a total solid state battery includes the assumption, that the interfacial contact between
the electrodes and the electrolyte is as good as possible. The interfacial resistance should be low for an easily intercalation
or deintercalation of lithium at the electrodes and the ionic conductivity of the electrolyte should be high.
A further critical aspect of the solid state battery is the porosity of the electrodes and the electrolyte. A homogeneous
surface coverage and a high density are useful for a high contact concentration between the grains of electrolyte itself and
between the electrolyte and the electrodes. As a possible electrolyte we have investigated the system Li4GeO4/Li3VO4, which we prepared in the stoichiometry Li3.6 Ge0.6 V0.4 O4. This lithium conducting system shows a high lithium conductivity of about 4 x 10−5 S/cm at room temperature and higher values at elevated temperatures. The conductivity is the result of interstitial Li cations
in the solid state solution.
The deposition of the inorganic thin film was done by a spray pyrolysis technique on different substrates. A variety of different
substrates were investigated as a function of adhesion and modified surface conditions. The aim is to find a correlation between
the substrate and the morphology of the thin film. The temperature of the deposition was varied between 400 and 600 °C. The
temperature dependent cristallinity was also studied. Furthermore the change of the unit cell volume and its constants a,
b and c has been investigated as a function of temperature by high temperature diffractometry. The thermal expansion coefficient
of the electrolyte could be calculated, to examine stresses with various substrates.
Paper presented at the 2nd Euroconference on Solid State Ionics, Funchal, Madeira, Portugal, Sept. 10–16, 1995 相似文献
16.
Potentiometric sensors based on zirconia can be used for determining gaseous NO at temperatures between 400 and 480 °C. For
such mixed potential sensors, NO sensitive electrode materials such as CdMn2O4 and V2O5 have been described. In order to improve the cell voltage response, composite electrode materials based on V2O5-γ-Al2O3 were investigated. Sensors employing these materials show a better voltage response and an improved adhesion to the solid
electrolyte compared with pure V2O5. The optimal temperature was found to be 440 °C. The NO sensitivity is nearly independent on the oxygen partial pressure
in the gas.
Paper presented at the 8th EuroConference on Ionics, Carvoeiro, Algarve, Portugal, Sept. 16–22, 2001. 相似文献
17.
Polymer electrolyte membranes, comprising of poly(methyl methacrylate) (PMMA), lithium tetraborate (Li2B4O7) as salt and dibutyl phthalate (DBP) as plasticizer were prepared using a solution casting method. The incorporation of DBP
enhanced the ionic conductivity of the polymer electrolyte. The polymer electrolyte containing 70 wt.% of poly(methyl methacrylate)–lithium
tetraborate and 30 wt.% of DBP presents the highest ionic conductivity of 1.58 × 10−7 S/cm. The temperature dependence of ionic conductivity study showed that these polymer electrolytes obey Vogel–Tamman–Fulcher
(VTF) type behaviour. Thermogravimetric analysis (TGA) was employed to analyse the thermal stability of the polymer electrolytes.
Fourier transform infrared (FTIR) studies confirmed the complexation between poly(methyl methacrylate), lithium tetraborate
and DBP. 相似文献
18.
Open circuit voltage (OCV) measurements in H2O/air concentration cells at T<580 K using Yb-doped SrCeO3 electrolyte indicate that under these conditions, protons are transported through the electrolyte as -ve ions, possibly as
hydroxyl (OH−) ions. The H+ ionic transport, which is generally reported, becomes the dominant mode for H2O/air concentration cells at temperatures greater than 750 K or when H2O/air electrodes are replaced by H2/Ar, and the anomalous OCV sign disappears. The combination of low temperature and the presence of hydrogen and oxygen as
provided by the H2O/air system appears to be necessary for the postulated hydroxyl ion electrode reactions to take place.
In addition to OCV measurements, results from impedance spectroscopy are used to provide evidence in support of the suggested
hydroxyl ion mode of protonic transport under the specified conditions. These findings are directly relevant in the development
of novel humidity sensors in the temperature range 450–580K and is reported in a separate paper in this conference.
Paper presented at the 3rd Euroconference on Solid State Ionics, Teulada, Sardinia, Italy, Sept. 15–22, 1996 相似文献
19.
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
20.
Thin films of mixed CeO2-TiO2 with different Ce/Ti mole ratios were prepared following an alcohol based sol-gel route via the spin coating technique using
mixed inorganic-organic [CeCl3.7H2O and Ti(OPr)4] precursors. Ion storage capacity for films obtained from aged sols was observed to be high. Enhanced titanium oxide content
improved the insertion capacity of the corresponding films as was evident from inserted charge determined by multiple step
chronoamperometric measurements. Electrochemical, optical, structural and thermal performances showed the suitability of the
films in an all solid state electrochromic (transmissive) device with tungsten trioxide (WO3) as electrochromic material and a conductive polymeric electrolyte based on lithium.
Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003. 相似文献