Nanocomposite ionic conductors in the Li2SO4Al2O3 system

Уваров, Н. Ф.; Bokhonov, Boris B.; Исупов, В. П.; Hairetdinov, E.F.

doi:10.1016/0167-2738(94)90432-4

Cited by 64 publications

(31 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This interaction can be explained by the adsorption of Ag ϩ cations on the Al 2 O 3 or ZrO 2 surface. 10 Since Al 2 O 3 or ZrO 2 are ionic crystals, defect concentration in the space-charge region 13 is rather high, and the highly conductive region is thus formed at the interface between AgI and Al 2 O 3 or ZrO 2 , respectively. The formation of such large interface areas between AgI and Al 2 O 3 or ZrO 2 should lead to a decrease of the average crystallite size or crystallinity of AgI.…”

Section: Journal Of the Electrochemical Society 149 ͑6͒ A773-a777 ͑2mentioning

confidence: 99%

“…8 The conductivity of the AgI-SiO 2 system is also about one order of magnitude higher than that of the system reported so far. 6 The large specific surface area and large pore volume of aerogels must contribute to higher defect densities in space charge regions 13 and thus these higher values of conductivity were observed. Figure 5 shows the DSC heating and cooling curves for (1-x)AgI•xZrO 2 composites using a ZrO 2 aerogel together with data for AgI crystal for comparison.…”

Section: Journal Of the Electrochemical Society 149 ͑6͒ A773-a777 ͑2mentioning

confidence: 99%

See 1 more Smart Citation

Conductivity Enhancement and Thermal Properties of AgI-MO[sub 2] (M=Zr, Si) Composites Using Sol-Gel Derived Aerogels

Tadanaga

Imai

Tatsumisago

et al. 2002

J. Electrochem. Soc.

View full text Add to dashboard Cite

AgI-ZrO 2 and AgI-SiO 2 composites were prepared using sol-gel derived aerogels. The conductivity at room temperature showed a maximum for the composition of 0.4AgI•0.6ZrO 2 or 0.4AgI•0.6SiO 2 and was 3.3 ϫ 10 Ϫ3 S cm Ϫ1 for the composite using ZrO 2 aerogels and 1.2 ϫ 10 Ϫ4 S cm Ϫ1 for the composite using SiO 2 aerogels. The diffusion of AgI into the micropores of the aerogel was observed for the ZrO 2 system, suggesting that the diffusion caused a decrease of the crystallinity of AgI and the formation of a high conductive phase of AgI at the AgI-ZrO 2 interface. In the SiO 2 -containing system, however, the diffusion was not observed and, hence, the conductivity was an order of magnitude lower than that of the ZrO 2 -based system. © 2002 The Electrochemical Society. ͓DOI: 10.1149/1.1475687͔ All rights reserved. In recent years there has been much interest in materials which show high ionic conductivity at room temperature, because they have potential application in various electrochemical devices such as all solid-state batteries, sensors, etc.1 Several approaches have been tried to increase the ionic conductivity of solid electrolytes. For example, the conductivity enhancement in the two-phase composites, which consist of ionically conducting and inorganic oxide ͑insulator͒ fine particles, has been studied since Liang reported the effect in LiI-Al 2 O 3 composites in 1973.2 Among these composites, AgI-based systems, such as AgI-MxOy (MxOy ϭ Al 2 O 3 ,SiO 2 ,ZrO 2 ,CeO 2 ,Fe 2 O 3 ), have been studied extensively. 3-11The mechanism of conductivity enhancement is unclear even now, but some models have been proposed. Most of them are based on the fact that the interface of ionic conductors and inorganic oxides plays an important role in conductivity enhancement. [9][10][11] From this point of view, further conductivity enhancement is expected by controlling ionic conductor-oxide interfaces.The sol-gel process is known to be a practical method for preparing oxides with a variety of characteristics. 12 In the sol-gel process, wet gels are prepared by hydrolysis of an alcoholic solution of metal alkoxides, and dried gels are porous materials with high porosity and large specific surface area. Thus, sol-gel derived oxides are expected to bring higher conductivity than the usual oxides in two-phase composites, because the large specific surface area of the gels can increase the area of ionic conductor-oxide interfaces, and micropores of the gels must be used as ion conduction pathway. Aerogels, which are formed by drying wet gels under a supercritical condition of the solvent used, have larger pore size and porosity than xerogels which are formed by drying wet gels under an ambient atmosphere. 12 We have already reported that the pore size of gels influences the conductivity and thermal properties of composites in the AgI-Al 2 O 3 system prepared using Al 2 O 3 aerogel and xerogel.11 These results indicated that the microstructure of aerogels was more effective than that of xerogels for enhancing the ionic conductivi...

show abstract

Section: Journal Of the Electrochemical Society 149 ͑6͒ A773-a777 ͑2mentioning

confidence: 99%

Section: Journal Of the Electrochemical Society 149 ͑6͒ A773-a777 ͑2mentioning

confidence: 99%

Conductivity Enhancement and Thermal Properties of AgI-MO[sub 2] (M=Zr, Si) Composites Using Sol-Gel Derived Aerogels

Tadanaga

Imai

Tatsumisago

et al. 2002

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…The appropriate mole percent of Na 2 SO 4 and dispersoid was weighed and mixed in the agate mortar using acetone as a medium. A series containing 5,10,20,30,35,40, and 50 mol% for each of the three dispersoids MgO, SiO 2 , and Al 2 O 3 were separately prepared at 900°C. The samples were heated for 6 h and were quenched in air to room temperature.…”

Section: Methodsmentioning

confidence: 99%

Electrical properties of Na2SO4-based composite systems

Bobade

Kulkarni

Gopalan

2007

Ionics

View full text Add to dashboard Cite

Composite electrolytes are well-known multiphase systems and exhibit maxima in the conductivity at certain second-phase concentration. An attempt has been made to investigate a number of sodium sulfate (Na 2 SO 4 )-based composite systems. The dispersoids that have been used are MgO, Al 2 O 3 , and SiO 2 . The samples have been characterized using impedance spectroscopy, X-ray diffraction, and differential scanning calorimetry. The maximum conductivity has been observed for MgO dispersed system, and the percolation threshold has been observed at 30-mol% dispersoid, MgO concentration. Interestingly, two maxima have been observed in case of the Na 2 SO 4 -SiO 2 and Na 2 SO 4 -Al 2 O 3 composite systems. In the Na 2 SO 4 -SiO 2 system, the first maximum occurs at lower concentration, i.e., in the range between 10 and 20 mol%, whereas the second occurs at the 40-mol% dispersoid concentration. For the Na 2 SO 4 -Al 2 O 3 system, although slightly indistinguishable, two peaks in the conductivity vs composition plot have been observed around 12-and 30-mol% Al 2 O 3 concentrations.

show abstract

“…For instance, dispersion of nanosized refractory oxides such as SiO 2 [86,87], Al 2 O 3 [88,89], Fe 2 O 3 , TiO 2 [90], ZrO 2 , MgO, etc. within pure oxo-acid salt phases allows considerable improvement to both the thermal stability and proton conductivity of the material.…”

Section: Membrane Nano-structurementioning

confidence: 99%

Materials for separation membranes in hydrogen and oxygen production and future power generation

Phair

Badwal²

2006

Science and Technology of Advanced Materials

110

View full text Add to dashboard Cite

Future fossil fuel power generation is likely to include technologies which increase process efficiency and reduce its impact on the environment, for example, CO 2 sequestration. Some of the key technologies identified for clean coal and natural gas combustion to produce power or hydrogen or both include O 2 generation/separation, H 2 and CO 2 separation. Hydrogen is considered as a potentially excellent substitute for transport fuels due to the concern over dwindling oil reserves and global warming. This paper discusses various separation processes that may be used in the industrial production of hydrogen from fossil fuels, with an emphasis on membrane separation technologies. Membrane separation has the advantage over other separation methods in that it is simple and potentially less energy intensive. Depending on the particular separation process utilised, however, the membrane materials can differ substantially. The materials used for H 2 , O 2 and CO 2 separation are discussed and the major similarities and differences between the membranes highlighted. Critical design aspects of the membrane such as multiple phase design, nano-structure control, the need for surface layers and fabrication processes are also reviewed as they represent the areas where most research and development effort is likely to be directed in the future. r

show abstract

Nanocomposite ionic conductors in the Li2SO4Al2O3 system

Cited by 64 publications

References 15 publications

Conductivity Enhancement and Thermal Properties of AgI-MO[sub 2] (M=Zr, Si) Composites Using Sol-Gel Derived Aerogels

Conductivity Enhancement and Thermal Properties of AgI-MO[sub 2] (M=Zr, Si) Composites Using Sol-Gel Derived Aerogels

Electrical properties of Na2SO4-based composite systems

Materials for separation membranes in hydrogen and oxygen production and future power generation

Contact Info

Product

Resources

About