Effect of SiO2 morphology and pores size on the proton nanocomposite electrolytes properties

Пономарева, В. Г.; Лаврова, Г. В.; Simonova, L. G.

doi:10.1016/s0167-2738(98)00517-7

Cited by 61 publications

(82 citation statements)

References 8 publications

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“…Generally, a single conductivity maximum has been reported in the literature for most of the Li þ , Ag þ , Na þ ion conducting composites with Al 2 O 3 as the dispersoid in contrast to the present proton conducting composites studied by us using hydrates and alumina which exhibit two conductivity maxima. From a careful scan of literature data, we could find some systems which also exhibit two peaks in the conductivity-composition isotherm [29][30][31][32] but due notice was either not taken or no effort was made to explain them. We propose the following two tentative models to find a qualitative explanation for the occurrence of two maxima in the conductivity-composition isotherm: Our present data cannot unequivocably establish either of the above two models.…”

Section: Total Ionic Transference Numbermentioning

confidence: 99%

Proton Conducting Composites of Heteropolyacid Hydrates (Phosphomolybdic and Phosphotungstic Acids) Dispersed with Insulating Al2O3

Lakshmi

Chandra

2001

phys. stat. sol. (a)

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Section: Total Ionic Transference Numbermentioning

confidence: 99%

Proton Conducting Composites of Heteropolyacid Hydrates (Phosphomolybdic and Phosphotungstic Acids) Dispersed with Insulating Al2O3

Lakshmi

Chandra

2001

phys. stat. sol. (a)

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“…However, Park et al [6,15] suggested that mechanisms of the electrical conductivity in H-bonded crystals must consider thermal dehydration, as well as ionic transport, because it is known that many H-bonded crystals reveal surface instabilities like thermal dehydration at high temperatures. Given that structural disorder facilitates ionic conduction, we studied the high-temperature phenomena and the dynamics of mobile protons in ADP-based composites since proton transport may be affected by the presence of outer and inner surfaces provided by highly dispersed ceramic nanoparticles, such as TiO 2 in the ADP solid matrix [16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Electrical relaxation in proton conductor composites based on (NH4)H2PO4/TiO2

Castillo

Materón

Castillo

et al. 2008

Ionics

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We report on electrical relaxation measurements of (1 − x)NH 4 H 2 PO 4 -xTiO 2 (x = 0.1) composites by admittance spectroscopy, in the 40-Hz-5-MHz frequency range and at temperatures between 303 and 563 K. Simultaneous thermal and electrical measurements on the composites identify a stable crystalline phase between 373 and 463 K. The real part of the conductivity, σ ', shows a power-law frequency dependence below 523 K, which is well described by Jonscher's expression σ = σ 0 (1 + (ω/ω p ) n ), where σ 0 is the dc conductivity, ω p /2π = f p is a characteristic relaxation frequency, and n is a fractional exponent between 0 and 1. Both σ 0 and f p are thermally activated with nearly the same activation energy in the II region, indicating that the dispersive conductivity originates from the migration of protons. However, activation energies decrease from 0.55 to 0.35 eV and n increases toward 1.0, as the concentration of TiO 2 nanoparticles increases, thus, enhancing cooperative correlation among moving ions. The highest dc conductivity is obtained for the composite x = 0.05 concentration, with values above room temperature about three orders of magnitude higher than that of crystalline NH 4 H 2 PO 4 (ADP), reaching values on the order of 0.1 ( cm) −1 above 543 K.

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“…In the low-temperature phase, the composites with SiO 2 and TiO 2 showed 2-3 orders of magnitude higher conductivity than that of pure cesium hydrogen sulphate, while proton conductivity in the superprotonic phase decreases by mixing inorganic particles [77,78].…”

Section: Inorganic Proton Conductorsmentioning

confidence: 97%

Diffusion in Solid Proton Conductors: Theoretical Aspects and Nuclear Magnetic Resonance Analysis

Vona

Sgreccia

Tosto

2012

Solid State Proton Conductors

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Water behavior in solid proton conductors is a considerably complex phenomenon. However, the knowledge of transport and diffusivity inside electrolytes is an important requirement for many applications. Extensive efforts have been made in terms of modeling water transport and its management. Accurate measurements of diffusion are required to validate these models and to optimize the performance of solid proton conductors.The focus of this chapter is the theoretical approach together with the use of nuclear magnetic resonance (NMR) techniques for the understanding of diffusion phenomena in solid proton conductors. The basic principles and the main NMR methods will be also discussed.

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Effect of SiO2 morphology and pores size on the proton nanocomposite electrolytes properties

Cited by 61 publications

References 8 publications

Proton Conducting Composites of Heteropolyacid Hydrates (Phosphomolybdic and Phosphotungstic Acids) Dispersed with Insulating Al2O3

Proton Conducting Composites of Heteropolyacid Hydrates (Phosphomolybdic and Phosphotungstic Acids) Dispersed with Insulating Al2O3

Electrical relaxation in proton conductor composites based on (NH4)H2PO4/TiO2

Diffusion in Solid Proton Conductors: Theoretical Aspects and Nuclear Magnetic Resonance Analysis

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