Effective energy landscapes for mobile ions in solid electrolytes

2004 ◽  
Vol 835 ◽  
Author(s):  
Stefan Adams
Keyword(s):  
Activation Energy ◽  
Ion Transport ◽  
Solid Electrolytes ◽  
Transport Mechanism ◽  
Bond Valence ◽  
Trivalent Cation ◽  
Effective Energy ◽  
Energy Landscapes ◽  
Mobile Species ◽  
Mobile Ions

ABSTRACTBond valence mismatch landscapes may serve as simple models of the effective energy landscapes for mobile ions in solid electrolytes. Thereby they provide a tool to identify the ion transport mechanism and allow to predict the activation energy of the ionic conduction. Accounting for the mass dependence of the conversion from the BV mismatch into an activation energy scale yields a correlation that holds for different types of mobile cations. While in most cases the analysis of bond valence mismatch landscapes is consistent with the ion transport mechanism derived from experimental or other computational evidence, the presumed prototype of trivalent cation conductors Sc2(WO4)3 is discussed as an example, where the BV analysis of transport pathways suggests that the interpretation of previous experimental investigations has to be reconsidered. Both bond valence calculations and molecular dynamics simulations suggests that the most probable mobile species in stoichiometric Sc2(WO4)3 is neither Sc3+ nor individual O2- but the complex divalent anion WO42-.

Improved bond valence models for ion transport pathways in glasses

2008 ◽  
Vol 1152 ◽  
Author(s):  
Stefan N. Adams
Keyword(s):  
Ion Transport ◽  
Solid Electrolytes ◽  
Functional Materials ◽  
Bond Valence ◽  
Structure Model ◽  
Structure Property ◽  
Static Structure ◽  
Transport Pathways ◽  
Lithium Metasilicate ◽  
Mobile Species

ABSTRACTStructure property function relationships provide valuable guidelines for a systematic development of functional materials. It is demonstrated how an augmented bond valence (BV) approach helps to establish such relationships in solid electrolytes. In principle it permits to identify mobile species, transport pathways and provides estimates for ion mobilities. In this work we discuss ion conduction pathways in glassy Lithium metasilicate as an illustrative example. The required representative local structure model is derived from Molecular Dynamics simulations, which provides the opportunity to compare the bond-valence-based predictions from a static structure model with a comprehensive analysis of a complete simulation trajectory. It is shown that understanding the bond valence mismatch as an effective Morse-type interaction opens up a way for systematically analyzing ion transport pathways and for a generally applicable method with improved reliability to predict ion transport characteristics in solid electrolytes from the structure model.

Ionic conductivity enhancement in Gd2Zr2O7 pyrochlore by Nd doping

2008 ◽  
Vol 23 (4) ◽  
pp. 911-916 ◽  
Author(s):  
B.P. Mandal ◽  
S.K. Deshpande ◽  
A.K. Tyagi
Keyword(s):  
Activation Energy ◽  
Ionic Conductivity ◽  
Preexponential Factor ◽  
Dc Conductivity ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Conductivity Enhancement ◽  
Mobile Species ◽  
Oxygen Ion ◽  
Mobile Ions

The pyrochlore compositions Gd2–yNdyZr2O7 (y = 0.0, 0.1, 0.4, 0.6, 1.0, 1.4, 1.6, and 2.0) were synthesized, and their ionic conductivity was determined (100 Hz–15 MHz, 622–696 K). The direct-current (dc) conductivity (σdc) varies upon Nd substitution at the Gd site, and a peaking effect in σdc was observed around y = 1.0. This indicates that a significant increase in conductivity can be obtained at moderately high temperatures by suitable doping at the Gd site with isovalent rare-earth ions like Nd. The extent of oxygen ion disorder determined from x-ray diffraction was found to decrease with increasing Nd content. The dc conductivity obeys the Arrhenius relation σdcT = σ0 exp(−E/kBT). The activation energy E and the preexponential factor σ0, which is a measure of the concentration of the mobile species, increase while going from the ordered Nd2Zr2O7 to the least ordered Gd2Zr2O7. These two processes presumably lead to the peaking of σdc at an intermediate Nd content. Our results also suggest that the cooperative motion of mobile ions does not contribute much to the increase in activation energy in this compound.

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 Quantification of the ion transport mechanism in protective polymer coatings on lithium metal anodes

2021 ◽  
Author(s):  
Hongyao Zhou ◽  
Haodong Liu ◽  
Xing Xing ◽  
Zijun Wang ◽  
Sicen Yu ◽  
...  
Keyword(s):  
Ion Transport ◽  
Transport Mechanism ◽  
Polymer Coatings ◽  
Rechargeable Batteries ◽  
Cycle Life ◽  
Lithium Metal ◽  
Lithium Metal Anodes ◽  
Protective Polymer ◽  
Deposition Morphology ◽  
Metal Anodes

Protective Polymer Coatings (PPCs) protect lithium metal anodes in rechargeable batteries to stabilize the Li/electrolyte interface and to extend the cycle life by reducing parasitic reactions and improving the lithium deposition morphology.

3DBVSMAPPER: a program for automatically generating bond-valence sum landscapes

2012 ◽  
Vol 45 (5) ◽  
pp. 1054-1056 ◽  
Author(s):  
Matthew Sale ◽  
Maxim Avdeev
Keyword(s):  
Computer Program ◽  
Three Dimensional ◽  
Bond Valence ◽  
Spatial Distributions ◽  
Energy Landscapes ◽  
Bond Valence Sum ◽  
Scripting Language ◽  
Materials Studio ◽  
User Intervention ◽  
Minimal User Intervention

A computer program,3DBVSMAPPER, was developed to generate bond-valence sum maps and bond-valence energy landscapes with minimal user intervention. The program is designed to calculate the spatial distributions of bond-valence values on three-dimensional grids, and to identify infinitely connected isosurfaces in these spatial distributions for a given bond-valence mismatch or energy threshold and extract their volume and surface area characteristics. It is implemented in the Perl scripting language embedded in AccelrysMaterials Studioand has the capacity to process automatically an unlimited number of materials using crystallographic information files as input.

Activation energy for alkaline-earth ion transport in low alkali aluminoborosilicate glasses

2013 ◽  
Vol 102 (8) ◽  
pp. 082904 ◽  
Author(s):  
Priyanka Dash ◽  
Eugene Furman ◽  
Carlo G. Pantano ◽  
Michael T. Lanagan
Keyword(s):  
Activation Energy ◽  
Ion Transport ◽  
Alkaline Earth

scholarly journals Crosslinked perfluoropolyether solid electrolytes for lithium ion transport

2017 ◽  
Vol 310 ◽  
pp. 71-80 ◽  
Author(s):  
Didier Devaux ◽  
Irune Villaluenga ◽  
Mahesh Bhatt ◽  
Deep Shah ◽  
X. Chelsea Chen ◽  
...  
Keyword(s):  
Ion Transport ◽  
Solid Electrolytes ◽  
Lithium Ion

Non-solvating, side-chain polymer electrolytes as lithium single-ion conductors: synthesis and ion transport characterization

2020 ◽  
Vol 11 (2) ◽  
pp. 461-471 ◽  
Author(s):  
Jiacheng Liu ◽  
Phillip D. Pickett ◽  
Bumjun Park ◽  
Sunil P. Upadhyay ◽  
Sara V. Orski ◽  
...  
Keyword(s):  
Ion Transport ◽  
Dielectric Relaxation ◽  
Polymer Electrolytes ◽  
Transport Mechanism ◽  
Lithium Ion ◽  
Side Chain ◽  
Chain Polymer ◽  
Single Ion Conductors ◽  
Ion Conductors

Non-solvating, side-chain polymer electrolytes with more dissociable pendent anion chemistries exhibit a dielectric relaxation dominated lithium ion transport mechanism.

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