Electroconvection near an ion-selective surface with Butler–Volmer kinetics

2021 ◽  
Vol 930 ◽  
Author(s):  
Gaojin Li ◽  
Alex Townsend ◽  
Lynden A. Archer ◽  
Donald L. Koch
Keyword(s):  
Ion Transport ◽  
Linear Stability ◽  
Scaling Laws ◽  
Liquid Electrolyte ◽  
Critical Voltage ◽  
Ion Diffusion ◽  
Effective Voltage ◽  
Diffusion Migration ◽  
Electrode Interface ◽  
Ion Deposition

We study the effects of interfacial kinetics on the electro-hydrodynamics of ion transport near an ion-selective surface using a combination of linear stability analysis and numerical simulation. The finite kinetics of the electrolyte–electrode interface affects the ion transfer and electroconvection in many ways. On a surface of fixed topography, such as a metal surface of slow and stable ion deposition or covered by a polymer membrane, the finite kinetics reduces the current in one-dimensional ion diffusion/migration, increases the critical voltage for the onset of the electroconvective instability, changes the dynamics of the electroconvection and the overlimiting current, and enhances the lateral ion diffusion within the interfacial layer. The first three effects are indirectly caused by the reaction kinetics and can be characterized by an effective voltage difference across the liquid electrolyte. In comparison, the last effect is controlled by a direct interplay between kinetics and nonlinear electroconvection. Scaling laws for ion transport and features of electroconvection are proposed. We also analyse the linear stability of a surface which evolves under ion deposition and find that the finite kinetics decreases the growth rate of both electroconvective and morphological instabilities and therefore modifies the wavenumber of the most unstable mode.

Enhanced Ion Transport in an Ether Aided Super Concentrated Ionic Liquid Electrolyte for Long-Life Practical Lithium Metal Battery Applications

2020 ◽  
Author(s):  
Urbi Pal ◽  
Fangfang Chen ◽  
Derick Gyabang ◽  
Thushan Pathirana ◽  
Binayak Roy ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ion Transport ◽  
Current Density ◽  
Coulombic Efficiency ◽  
High Energy ◽  
Liquid Electrolyte ◽  
High Mass ◽  
Lithium Metal ◽  
Ionic Liquid Electrolyte ◽  
Lithium Metal Battery

We explore a novel ether aided superconcentrated ionic liquid electrolyte; a combination of ionic liquid, <i>N</i>-propyl-<i>N</i>-methylpyrrolidinium bis(fluorosulfonyl)imide (C<sub>3</sub>mpyrFSI) and ether solvent, <i>1,2</i> dimethoxy ethane (DME) with 3.2 mol/kg LiFSI salt, which offers an alternative ion-transport mechanism and improves the overall fluidity of the electrolyte. The molecular dynamics (MD) study reveals that the coordination environment of lithium in the ether aided ionic liquid system offers a coexistence of both the ether DME and FSI anion simultaneously and the absence of ‘free’, uncoordinated DME solvent. These structures lead to very fast kinetics and improved current density for lithium deposition-dissolution processes. Hence the electrolyte is used in a lithium metal battery against a high mass loading (~12 mg/cm<sup>2</sup>) LFP cathode which was cycled at a relatively high current rate of 1mA/cm<sup>2</sup> for 350 cycles without capacity fading and offered an overall coulombic efficiency of >99.8 %. Additionally, the rate performance demonstrated that this electrolyte is capable of passing current density as high as 7mA/cm<sup>2</sup> without any electrolytic decomposition and offers a superior capacity retention. We have also demonstrated an ‘anode free’ LFP-Cu cell which was cycled over 50 cycles and achieved an average coulombic efficiency of 98.74%. The coordination chemistry and (electro)chemical understanding as well as the excellent cycling stability collectively leads toward a breakthrough in realizing the practical applicability of this ether aided ionic liquid electrolytes in lithium metal battery applications, while delivering high energy density in a prototype cell.

scholarly journals A single cation or anion dendrimer-based liquid electrolyte

2016 ◽  
Vol 7 (5) ◽  
pp. 3390-3398 ◽  
Author(s):  
Sudeshna Sen ◽  
Rudresha B. Jayappa ◽  
Haijin Zhu ◽  
Maria Forsyth ◽  
Aninda J. Bhattacharyya
Keyword(s):  
Ion Transport ◽  
Transference Number ◽  
Liquid Electrolyte ◽  
Ion Conductor ◽  
Ionic Transference Number ◽  
Anion Diffusion

The proposed dendrimer based liquid electrolyte is a single-ion conductor where ion transport is altered by the nature of the chemical functionalities leading to large variations in anion diffusion and hence ionic transference number.

scholarly journals Shear instability of an axisymmetric air–water coaxial jet

2018 ◽  
Vol 843 ◽  
pp. 575-600 ◽  
Author(s):  
Jean-Philippe Matas ◽  
Antoine Delon ◽  
Alain Cartellier
Keyword(s):  
Surface Tension ◽  
Stability Analysis ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Convective Instability ◽  
Scaling Laws ◽  
Shear Instability ◽  
Liquid Jet ◽  
Absolute Instability ◽  
Instability Waves

We study the destabilization of a round liquid jet by a fast annular gas stream. We measure the frequency of the shear instability waves for several geometries and air/water velocities. We then carry out a linear stability analysis, and show that there are three competing mechanisms for the destabilization: a convective instability, an absolute instability driven by surface tension and an absolute instability driven by confinement. We compare the predictions of this analysis with experimental results, and propose scaling laws for wave frequency in each regime. We finally introduce criteria to predict the boundaries between these three regimes.

scholarly journals Towards Understanding the Different Influences of Grain Boundaries on Ion Transport in Sulfide and Oxide Solid Electrolytes

2019 ◽  
Author(s):  
James Dawson ◽  
Pieremanuele Canepa ◽  
Matthew Clarke ◽  
Theodosios Famprikis ◽  
Dibyajyoti Ghosh ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Ion Transport ◽  
Grain Boundaries ◽  
Solid Electrolytes ◽  
Ionic Conductivities ◽  
Liquid Electrolyte ◽  
Boundary Resistance ◽  
Polycrystalline Materials ◽  
Solid State Batteries ◽  
And Performance

Solid electrolytes provide a route to the development of all-solid-state batteries that can potentially surpass the safety and performance of conventional liquid electrolyte-based devices. Sulfide solid electrolytes have received particular attention as a result of their high ionic conductivities. One of the main reasons for such high ionic conductivity is the apparently reduced grain boundary resistance of sulfide solid electrolytes compared to their oxide counterparts, but this is not fully established. Using two model electrolyte systems, Na3PS4 and Na3PO4, we apply a novel microscale simulation approach to analyze ionic transport in polycrystalline materials with various grain volumes. For Na3PO4, high grain boundary resistance is found, with the Na-ion conductivity decreasing with decreasing grain volume. For Na3PS4, the overall influence of grain boundaries is significantly reduced compared to the oxide. Detailed analysis reveals a minimal change in the local structures and Na-ion conduction mechanism between bulk and polycrystalline Na3PS4, whereas the change is far more substantial for Na3PO4, with evidence of over-coordination of Na ions at the grain boundaries. Our microscale approach helps to explain the fundamentally different influences of grain boundaries on ion transport in phosphate and thiophosphate solid electrolytes.

scholarly journals Atomic-scale ion transistor with ultrahigh diffusivity

Science ◽  
2021 ◽  
Vol 372 (6541) ◽  
pp. 501-503
Author(s):  
Yahui Xue ◽  
Yang Xia ◽  
Sui Yang ◽  
Yousif Alsaid ◽  
King Yan Fong ◽  
...  
Keyword(s):  
Ion Transport ◽  
Energy Barrier ◽  
Critical Energy ◽  
Bulk Water ◽  
Atomic Scale ◽  
Optical Measurements ◽  
Threshold Behavior ◽  
Ion Diffusion ◽  
Reduced Graphene

Biological ion channels rapidly and selectively gate ion transport through atomic-scale filters to maintain vital life functions. We report an atomic-scale ion transistor exhibiting ultrafast and highly selective ion transport controlled by electrical gating in graphene channels around 3 angstroms in height, made from a single flake of reduced graphene oxide. The ion diffusion coefficient reaches two orders of magnitude higher than the coefficient in bulk water. Atomic-scale ion transport shows a threshold behavior due to the critical energy barrier for hydrated ion insertion. Our in situ optical measurements suggest that ultrafast ion transport likely originates from highly dense packing of ions and their concerted movement inside the graphene channels.

scholarly journals Ion diffusion coefficients in poly(3-alkylthiophenes) for energy conversion and biosensing: role of side-chain length and microstructure

2020 ◽  
Vol 8 (38) ◽  
pp. 13319-13327 ◽  
Author(s):  
Jonathan K. Harris ◽  
Erin L. Ratcliff
Keyword(s):  
Ion Transport ◽  
Energy Conversion ◽  
Chain Length ◽  
Diffusion Coefficients ◽  
Side Chain ◽  
Ion Diffusion ◽  
Ion Movement ◽  
Ion Imprinted ◽  
Electrochemically Deposited

Electrochemically deposited conductive polymers, with their ion imprinted channels, can increase ion transport speed by three orders of magnitude over their spin coated counterparts by eliminating energetic traps for ion movement.

Enhanced ion transport in an ether aided super concentrated ionic liquid electrolyte for long-life practical lithium metal battery applications

2020 ◽  
Vol 8 (36) ◽  
pp. 18826-18839 ◽  
Author(s):  
Urbi Pal ◽  
Fangfang Chen ◽  
Derick Gyabang ◽  
Thushan Pathirana ◽  
Binayak Roy ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ion Transport ◽  
Transport Mechanism ◽  
Liquid Electrolyte ◽  
Lithium Metal ◽  
Ionic Liquid Electrolyte ◽  
Long Life ◽  
Lithium Metal Battery

We explore a superconcentrated electrolyte comprising N-propyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide, 1,2 dimethoxyethane and 3.2 mol kg−1 LiFSI. It offers an alternative ion-transport mechanism, improved fluidity and ultra-stable Li metal battery performance.

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