Bombardment Induced Ion Transport through Ion Conducting Glasses

2016 ◽  
Vol 6 ◽  
pp. 107-143 ◽  
Author(s):  
Karl Michael Weitzel
Keyword(s):  
Ion Transport ◽  
Diffusion Coefficients ◽  
Particle Density ◽  
Ion Beam ◽  
Ionic Conductivities ◽  
Metal Electrode ◽  
Theoretical Modelling ◽  
Concentration Profiles ◽  
Surface Particle ◽  
Ion Conducting

The recently developed bombardment induced ion transport (BIIT) technique is reviewed. BIIT is based on shining an energy-selected alkali ion beam at the surface of a sample of interest. Attachment of these ions leads to the build-up of a surface potential and a surface particle density. This in turn generates the corresponding gradients which induce ion transport towards a single metal electrode connected to the backside of the sample where it is detected as a neutralization current. Two different versions of BIIT are presented, i.) the native ion BIIT and ii.) the foreign ion BIIT. The former is demonstrated to provide access to absolute ionic conductivities and activation energies, the latter leads to the generation of electrodiffusion profiles. Theoretical modelling of these concentration profiles by means of the Nernst-Planck-Poisson theory allows to deduce the concentration dependence of diffusion coefficients.

Bond valence analysis of ion transport in reverse Monte Carlo models of mixed alkali glasses

2002 ◽  
Vol 756 ◽  
Author(s):  
Stefan Adams ◽  
Jan Swenson
Keyword(s):  
Ion Transport ◽  
High Efficiency ◽  
Volume Fraction ◽  
Ionic Conductivities ◽  
Bond Valence ◽  
Mixed Alkali ◽  
Mixed Alkali Effect ◽  
Ion Conducting ◽  
Mobile Ions ◽  
Bond Valence Analysis

ABSTRACTAn analysis of RMC structure models of ion conducting glasses in terms of our bond softness sensitive bond-valence method enables us to identify the conduction pathways for a mobile ion as regions of sufficiently low valence mismatch. The strong correlation between the volume fraction F of the “infinite pathway cluster” and the transport properties yields a prediction of both the absolute value and activation energy of the dc ionic conductivities directly from the structural models. Separate correlations for various types of mobile cations can be unified by employing the square root of the cation mass as a scaling factor. From the application of this procedure to RMC models of mixed alkali glasses, the mixed alkali effect, i.e. the extreme drop of the ionic conductivity when a fraction of the mobile ions is substituted by another type of mobile ions may be attributed mainly to the blocking of conduction pathways by unlike cations. The high efficiency of the blocking can be explained by the reduced fractal dimension of the pathways on the length scale of individual ion transport steps.

scholarly journals Theoretical Modelling of Ion Exchange Processes in Glass: Advances and Challenges

2021 ◽  
Vol 11 (11) ◽  
pp. 5070
Author(s):  
Xesús Prieto-Blanco ◽  
Carlos Montero-Orille
Keyword(s):  
Ion Exchange ◽  
Diffusion Coefficients ◽  
Molten Salts ◽  
Theoretical Modelling ◽  
Copper Films ◽  
Theoretical Frameworks ◽  
Self Diffusion ◽  
Exchange Processes ◽  
The One ◽  
Made In

In the last few years, some advances have been made in the theoretical modelling of ion exchange processes in glass. On the one hand, the equations that describe the evolution of the cation concentration were rewritten in a more rigorous manner. This was made into two theoretical frameworks. In the first one, the self-diffusion coefficients were assumed to be constant, whereas, in the second one, a more realistic cation behaviour was considered by taking into account the so-called mixed ion effect. Along with these equations, the boundary conditions for the usual ion exchange processes from molten salts, silver and copper films and metallic cathodes were accordingly established. On the other hand, the modelling of some ion exchange processes that have attracted a great deal of attention in recent years, including glass poling, electro-diffusion of multivalent metals and the formation/dissolution of silver nanoparticles, has been addressed. In such processes, the usual approximations that are made in ion exchange modelling are not always valid. An overview of the progress made and the remaining challenges in the modelling of these unique processes is provided at the end of this review.

scholarly journals Migration of mineral oil in elastomers

2021 ◽  
Author(s):  
Tobias Förster ◽  
Artur Blivernitz
Keyword(s):  
Diffusion Coefficients ◽  
Mineral Oil ◽  
Activation Energies ◽  
Concentration Profiles ◽  
Small Reservoir ◽  
Experimental Procedure ◽  
Mineral Oils ◽  
The Absolute ◽  
Suitable Measure

AbstractThis work describes a newly introduced experimental procedure to quantify the diffusion progress of mineral oils locally resolved in NBR. Diffusion of reference oils IRM 901, IRM 902 and IRM 903 in NBR with various acrylonitrile contents was investigated. Classical sorption experiments were performed as a basic characterization and compared to the newly introduced method. Here, elastomer specimens are only being dipped with the bottom in a relatively small reservoir of mineral oil. This provides a determination of locally resolved concentration profiles of mineral oils, and the calculation of diffusion coefficients. These diffusion coefficients follow the same trends like those determined via sorption experiments. Despite differences in the absolute numbers, activation energies of diffusion can be applied as a suitable measure for the compatibility of elastomers and fluids.

scholarly journals Structural, Electrical and Electrochemical Properties of Glycerolized Biopolymers Based on Chitosan (CS): Methylcellulose (MC) for Energy Storage Application

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1183
Author(s):  
Shujahadeen B. Aziz ◽  
Ahmad S. F. M. Asnawi ◽  
Mohd Fakhrul Zamani Kadir ◽  
Saad M. Alshehri ◽  
Tansir Ahamad ◽  
...  
Keyword(s):  
Energy Storage ◽  
Ion Transport ◽  
Ammonium Thiocyanate ◽  
Transference Number ◽  
Ionic Mobility ◽  
Transport Parameters ◽  
Ionic Transference Number ◽  
Energy Storage Application ◽  
Electrochemical Double Layer ◽  
Ion Conducting

In this work, a pair of biopolymer materials has been used to prepare high ion-conducting electrolytes for energy storage application (ESA). The chitosan:methylcellulose (CS:MC) blend was selected as a host for the ammonium thiocyanate NH4SCN dopant salt. Three different concentrations of glycerol was successfully incorporated as a plasticizer into the CS–MC–NH4SCN electrolyte system. The structural, electrical, and ion transport properties were investigated. The highest conductivity of 2.29 × 10−4 S cm−1 is recorded for the electrolyte incorporated 42 wt.% of plasticizer. The complexation and interaction of polymer electrolyte components are studied using the FTIR spectra. The deconvolution (DVN) of FTIR peaks as a sensitive method was used to calculate ion transport parameters. The percentage of free ions is found to influence the transport parameters of number density (n), ionic mobility (µ), and diffusion coefficient (D). All electrolytes in this work obey the non-Debye behavior. The highest conductivity electrolyte exhibits the dominancy of ions, where the ionic transference number, tion value of (0.976) is near to infinity with a voltage of breakdown of 2.11 V. The fabricated electrochemical double-layer capacitor (EDLC) achieves the highest specific capacitance, Cs of 98.08 F/g at 10 mV/s by using the cyclic voltammetry (CV) technique.

scholarly journals Sodium, Silver and Lithium-Ion Conducting β″-Alumina + YSZ Composites, Ionic Conductivity and Stability

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 293
Author(s):  
Liangzhu Zhu ◽  
Anil V. Virkar
Keyword(s):  
Ion Exchange ◽  
Electrochemical Impedance ◽  
Ionic Conductivities ◽  
Lithium Ion ◽  
Co2 Corrosion ◽  
Ionic Conductors ◽  
Ion Conductor ◽  
Sensor Applications ◽  
Potential Applications ◽  
Ion Conducting

Na-β″-alumina (Na2O.~6Al2O3) is known to be an excellent sodium ion conductor in battery and sensor applications. In this study we report fabrication of Na- β″-alumina + YSZ dual phase composite to mitigate moisture and CO2 corrosion that otherwise can lead to degradation in pure Na-β″-alumina conductor. Subsequently, we heat-treated the samples in molten AgNO3 and LiNO3 to respectively form Ag-β″-alumina + YSZ and Li-β″-alumina + YSZ to investigate their potential applications in silver- and lithium-ion solid state batteries. Ion exchange fronts were captured via SEM and EDS techniques. Their ionic conductivities were measured using electrochemical impedance spectroscopy. Both ion exchange rates and ionic conductivities of these composite ionic conductors were firstly reported here and measured as a function of ion exchange time and temperature.

scholarly journals Designing electrolytes with polymerlike glass-forming properties and fast ion transport at low temperatures

2020 ◽  
Vol 117 (42) ◽  
pp. 26053-26060
Author(s):  
Qing Zhao ◽  
Xiaotun Liu ◽  
Jingxu Zheng ◽  
Yue Deng ◽  
Alexander Warren ◽  
...  
Keyword(s):  
Ion Transport ◽  
Lithium Iron Phosphate ◽  
Coulombic Efficiency ◽  
High Capacity ◽  
Ionic Conductivities ◽  
Iron Phosphate ◽  
Cyclic Ether ◽  
Activation Entropy ◽  
Metal Electrodes ◽  
Metal Anodes

In the presence of Lewis acid salts, the cyclic ether, dioxolane (DOL), is known to undergo ring-opening polymerization inside electrochemical cells to form solid-state polymer batteries with good interfacial charge-transport properties. Here we report that LiNO3, which is unable to ring-open DOL, possesses a previously unknown ability to coordinate with and strain DOL molecules in bulk liquids, completely arresting their crystallization. The strained DOL electrolytes exhibit physical properties analogous to amorphous polymers, including a prominent glass transition, elevated moduli, and low activation entropy for ion transport, but manifest unusually high, liquidlike ionic conductivities (e.g., 1 mS/cm) at temperatures as low as −50 °C. Systematic electrochemical studies reveal that the electrolytes also promote reversible cycling of Li metal anodes with high Coulombic efficiency (CE) on both conventional planar substrates (1 mAh/cm2over 1,000 cycles with 99.1% CE; 3 mAh/cm2over 300 cycles with 99.2% CE) and unconventional, nonplanar/three-dimensional (3D) substrates (10 mAh/cm2over 100 cycles with 99.3% CE). Our finding that LiNO3promotes reversibility of Li metal electrodes in liquid DOL electrolytes by a physical mechanism provides a possible solution to a long-standing puzzle in the field about the versatility of LiNO3salt additives for enhancing reversibility of Li metal electrodes in essentially any aprotic liquid electrolyte solvent. As a first step toward understanding practical benefits of these findings, we create functional Li||lithium iron phosphate (LFP) batteries in which LFP cathodes with high capacity (5 to 10 mAh/cm2) are paired with thin (50 μm) lithium metal anodes, and investigate their galvanostatic electrochemical cycling behaviors.

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