Ion Concentration Gradients Research Articles

Coupled mutual diffusion in aqueous paracetamol + sodium hydroxide solutions

Ternary mutual diffusion coefficients (Dik) measured by the Taylor dispersion method are reported for aqueous paracetamol + NaOH solutions at 25.00 °C and concentrations up to 0.050 mol dm−3. The coupled diffusion of paracetamol (1) and NaOH (2) is significant, as indicated by the large negative cross-diffusion coefficients. In sodium hydroxide solutions, paracetamol, a weak acid, is partially converted to its sodium salt. To help interpret the results, the measured Dik coefficients are compared with predictions based on Nernst and Nernst-Planck equations for mixed electrolyte solutions. The analysis shows that the diffusion of the paracetamol and sodium hydroxide components is strongly coupled by the electric field (diffusion potential) generated by the ionic concentration gradients.

Anomalous potentials on bilayer lipid membranes in the presence of usnic acid: Markin-Sokolov versus Nernst-Donnan equilibrium

To gain insight into the mechanisms of ionophoric activity of usnic acid (UA), we examined the UA-induced generation of potentials on a planar bilayer lipid membrane (BLM) in the presence of concentration gradients of hydrogen and magnesium or calcium ions under open-circuit conditions. Remarkably, the BLM potential generated by UA at the proton concentration gradient of 1 pH unit was approximately twice the Nernst equilibrium level. With a concentration gradient of magnesium or calcium ions, the BLM potential generated by UA had the opposite sign. The observed anomalies in the membrane potentials were consistent with a theory developed by Markin and Sokolov (Bioelectrochem. Bioenerg. 1990) for the case of ionophore-mediated coupled fluxes of several ions across a membrane.

Impact of mechanical stiffening and softening on the spatial distribution of lithium ions in spherical electrode particle under galvanostatic charging

This article investigates the lithiation of low-expansion electrode particles with concentration-dependent properties. The conventional electrochemical coupled stress equations do not take into account concentration dependency, especially for particles with a low volume of expansion, as they are assumed to have no impact on the lithium-ion (Li-ion) migration. However, considerable changes are observed in the present study when this factor is included. The Li-ion concentration gradient is observed to decrease with stiffening and increase with softening in an electrode particle. The stresses at the center of the particle increase with stiffening and reduce with the softening. It is observed that the effect of concentration-dependent elastic modulus on the concentration gradient of lithium ions at the surface of the particle is more prominent at higher charging rates. The stresses in the electrode particle are observed to increase in proportion to an increase in the charging rate up to a critical limit beyond which its magnitude reduces.

Impact of ion partitioning and double layer polarization on diffusiophoresis of a pH-regulated nanogel

Diffusiophoresis of a charge regulated spherical polyelectrolyte nanogel (PE) due to an externally imposed ionic concentration gradient is considered. The immobile charge density of the nanogel develops through the association/dissociation reactions of their inorganic functional groups. The nanogel is ion and fluid permeable with dielectric permittivity different from that of the surrounding electrolyte medium. This difference in dielectric permittivity creates an ion partitioning due to the difference in self energy of ions. The Nernst–Planck equation for ion transport and the Poisson equation (PNP) for the electric field are modified to take into account the ion partitioning effects. The diffusiophoresis mechanism is governed by the electrophoresis generated by the induced electric field and chemiphoresis develops due to the mitigation of counterions across the double layer of the nanogel. In addition, the convection dominated double layer polarization and the counterion condensation as well as the electroosmotic flow created by the gel immobile charge play a role in the diffusiophoresis. All these effects are incorporated through the modified PNP equations coupled with the Navier–Stokes equations. The governing equations in their full form are solved numerically through a control volume approach. Present computed solutions for the limiting cases are in good agreement with the existing solutions based on the first-order perturbation analysis. In order to illustrate the diffusiophoresis mechanism we have measured the induced electric field and effective charge density of the PE and analyzed its dependence on several electrokinetic parameters. The contribution due to chemiphoresis is low for PE compared to a rigid colloid. For a highly permeable PE the diffusiophoretic velocity increases and approaches a saturation for higher range of the PE fixed charge density. The ion partitioning effect depletes counterions in PE to manifests its diffusiophoretic velocity. The diffusiophoretic velocity of PE for pH > IEP is higher than the case for which pH < IEP.

Moving Binary-Color Heterojunction for Spatiotemporal Multilevel Encryption via Directional Swelling and Anion Exchange.

Naked-eye-visible color/graphical patterns have shown significant potential in optical encryption. However, current strategies for optical encryption are usually based on static or homogeneous information, which limits their applications in multivalue coding and advanced confidential encryption. Here, we propose a concept of spatiotemporally tunable optical encryption by constructing a multilevel binary-color spatial heterojunction pattern into the time dimension. This multiple coding strategy can enable a simple pattern much more difficult to be counterfeited and keep the facile authentication by naked eyes or smartphone at the same time. As a proof of concept, we fabricated a moving red-green heterojunction pattern by elaborately utilizing the directional swelling process of a poly(dimethylsiloxane) matrix in organic solvents and the ion-exchange property of a perovskite quantum dot wrapped in it. We demonstrate that trioctylphosphine plays a significant role in endowing the red-green heterojunction with a stable and distinct interface for better perception by eyes. The directional swelling and following ion-exchange dynamics in the local interface indicate that we can tailor the movement of the binary-color heterojunction in a quasi-continuous way via orthogonal variables of swelling ratio and ion concentration gradient. The concept of heterojunction-based multivalue optical encryption in the time dimension is independent with other dimensions, indicating a promising compatibility with the existing optical encryption systems.

Level of natremia as an index of the condition of the organism of animals under stress

In the diagnosis of stressful conditions in humans and other animals, ionic indicators remain practically unused. In this work, we studied the changes in the concentrations of sodium ions in the blood plasma of freshwater fish under stress caused by stressors of different quality and quantity. Most of the experiments were carried out on adult bream (Abramis brama L) from the Rybinsk Reservoir. Separate experiments were duplicated on adult individuals of roach (Rutilus rutilus L.), pike (Esox lucius L.), and blue bream (Abramis ballerus L.). The concentration of cations in the blood plasma was determined using a Flapho-4 flame photometer. Under the action of mild and short-term stressors of different qualities, the sodium concentration in the internal environment altered toward an increase in concentration gradients on the cell membrane (eustress or physiological stress). Hypernatremia was approximately 10%. Under the action of strong and/or prolonged stressors of different strength, the sodium concentration in the internal environment changed toward a decrease in concentration gradients on the cell membrane (distress or pathological stress). Hyponatremia was 50% in the conditions of acute lethal stress, 20% in subacute lethal stress, 10% or more in chronic lethal stress. During strong acute reversible stress, hyponatremia could reach 30%. Analysis of the material on mammals allowed us to conclude that the adaptation mechanisms in fish and higher vertebrates are similar. In this work, for the first time, the state of the system of electrolyte balance of animals under stress was analyzed from the standpoint of the leading role of ionic concentration gradients on the cell membrane (mainly sodium) in the energetics (level of disequilibrium) of the organism. We propose a concept that in normal and extreme conditions fish use two different defense reactions (or adaptation strategies): active and passive, consisting, respectively, in increasing or decreasing the level of disequilibrium (energy) in the organism. The hyponatremia recorded by numerous authors, which accompanies diseases in humans, is evidently a nonspecific reaction of the organism and serves as an indicator of reduced energy of the organism. It is suggested that the sodium level in the internal environment of the organism be used for diagnosing the stress state of animals.

Single‐Ion Conducting Polymer Electrolytes for Solid‐State Lithium–Metal Batteries: Design, Performance, and Challenges

AbstractRealizing solid‐state lithium batteries with higher energy density and enhanced safety compared to the conventional liquid lithium‐ion batteries is one of the primary research and development goals set for next‐generation batteries in this decade. In this regard, polymer electrolytes have been widely researched as solid electrolytes due to their excellent processability, flexibility, and low weight. With high cationic transference numbers (tLi+close to 1), single‐ion conducting polymer electrolytes (SICPEs) have tremendous advantages compared to polymer electrolyte systems (tLi+ &lt; 0.4) because of their potential to reduce the buildup of ion concentration gradients and suppress growth of lithium dendrites. The current review covers the fundamentals of SICPEs, including anionic unit synthesis, polymer structure design, and film fabrication, along with simulation and experimental results in solid‐state lithium–metal battery applications. A perspective on current challenges, possible solutions, and potential research directions of SICPEs is also discussed to provide the research community with the critical technical aspects that may advance SICPEs as solid electrolytes in next‐generation energy storage systems.

Quantitative measurement of ion transport phenomena in an operating lithium-ion battery by low-energy X-ray microscopy and nuclear magnetic resonance spectroscopy

In this study, quantitative measurements of lithium ion concentrations in an operating lithium-ion battery (LIB) with a graphite anode were achieved using low-energy X-ray microscopy and nuclear magnetic resonance (NMR) spectroscopy. The concentration distributions of lithium ions inside the graphite anode and the separator were able to be investigated quantitatively. Higher discharge rates produced steep ion concentration gradients inside of the LIB. At a 3C discharge rate, the ion concentration reached 2.5 M inside the anode. However, it was observed that the lithium ion was depleted near the cathode and that the discharge stopped because of an increase of overvoltage. To investigate the validity of the measurement, the diffusion coefficient of ions was measured by NMR, and the lithium-ion flux was calculated from the concentration gradient. The results showed good agreement with the theoretical values obtained from the discharge rate, which indicates that ion transport phenomena in the electrodes of operating LIBs can be evaluated quantitatively with this combination of low-energy X-ray microscopy and NMR.

Model Analysis of Post-Stimulation Effect on Axonal Conduction and Block.

To reveal the possible contribution of changes in membrane ion concentration gradients and ion pump activity to axonal conduction/block induced by long-duration electrical stimulation. A new model for conduction and block of unmyelinated axons based on the classical Hodgkin-Huxley (HH) equations is developed to include changes in Na+ and K+ concentrations and ion pumps. The effect of long-duration stimulation on axonal conduction/block is analyzed by computer simulation using this new model. The new model successfully simulates initiation, propagation, and block of action potentials induced by short-duration (multiple milliseconds) stimulations that do not significantly change the ion concentrations in the classical HH model. In addition, the activity-dependent effects such as action potential attenuation and broadening observed in animal studies are also successfully simulated by the new model. Finally, the model successfully simulates axonal block occurring after terminating a long-duration (multiple seconds) direct current (DC) stimulation as observed in recent animal studies and reveals 3 different mechanisms for the post-DC block of axonal conduction. Ion concentrations and pumps play an important role in post-stimulation effects and activity-dependent effects on axonal conduction/block. The duration of stimulation is a determinant factor because it influences the total charges applied to the axon, which in turn determines the ion concentrations inside and outside the axon. Despite recent clinical success of many neurostimulation therapies, the effects of long-duration stimulation on axonal conduction/block are poorly understood. This new model could significantly impact our understanding of the mechanisms underlying different neurostimulation therapies.

Time-Lapse, Live-Cell Imaging of Potassium Efflux in Cell Exposed to Nanosecond Pulsed Electric Fields

Electric-field-induced cell membrane permeabilization (electroporation) is used in a wide range of applications, from cancer therapy to food processing. The mechanisms underlying this phenomenon are, however, poorly understood. Electroporation is generally thought to involve the formation of transient pores, and perhaps other conductive structures, in the cell membrane. This enables the transport of normally impermeant material across the membrane and disrupts the intracellular:extracellular ion concentration gradients (Na+, K+, Cl-) maintained by intact cells.

Can Complete Transporter Mechanisms be Inferred from Experimental Data?

Membrane cotransporters perform essential cellular functions, selectively transporting nutrients as well as maintaining ion concentration gradients. Although careful structural, biochemical, and electrophysiological studies have revealed important elements of transporter mechanisms, numerous aspects remain ambiguous. Generally, the precise order of binding events is unknown, and it remains an open question whether multiple mechanistic pathways are at play. Here we address the identifiability question: Which mechanistic details can be resolved in principle based on both typical and idealized experimental data? Our approach builds on previous work to search and fit models using the entire allowed transporter reaction and state space.

Stationary Electro-osmotic Flow Driven by ac Fields around Insulators

Electric fields are commonly used for manipulating particles and liquids in microfluidic systems. In this work, we report stationary electro-osmotic flow vortices around dielectric micropillars induced by ac electric fields in electrolytes. The flow characteristics are theoretically predicted based on the well-known phenomena of surface conductance and concentration polarization around a charged object. The stationary flows arise from two distinct contributions working together: an oscillating nonuniform zeta potential induced around the pillar and a rectified electric field induced by the ion concentration gradients. We refer to this fluid flow as concentration-polarization electro-osmosis (CPEO). We present experimental data in support of the theoretical predictions. The magnitude and frequency dependence of the electro-osmotic velocity are in agreement with the theoretical estimates and are significantly different from predictions based on the standard theory for induced-charge electro-osmosis, which has previously been postulated as the origin of the stationary flow around dielectric objects. In addition to furthering our understanding of the influence of ac fields on fluid flows, we anticipate that this work will also expand the use of ac fields for flow control in microfluidic systems.

In-situ monitoring of the electrochemical corrosion behavior in fluoride environment of cellular structured Ti6Al4V alloy fabricated by electron beam melting

The variation of electrochemical corrosion behavior with pore depth in porous Ti6Al4V alloys produced by electron beam melting (EBM) was studied in situ by a unique simulation model in acidic solution containing fluoride (PBS-H-F). The results suggested that steady-state pitting occurred at shallow pore depth position, while the sample at deep pore depth position exhibited superior corrosion resistance. The degree of corrosion on the surface was decreased with the increase in pore depth, including susceptibility to pitting, a behavior attributed to the concentration gradient of fluoride ions inside the pores.

Choroid plexus epithelial cells as a model to study nongenomic steroid signaling and its effect on ion channel function.

The choroid plexus (CP) is an epithelial tissue primarily responsible for the secretion of the cerebrospinal fluid (CSF). Choroid plexuses are found in each of the four brain ventricles: two laterals, third and fourth. They ensure continuous production of CSF to provide nutrients, remove waste products and provide a mechanical buffer to protect the brain. Tight junctions in the CP epithelium form a barrier between the blood plasma and the CSF, which allow channels and transporters in the CP to establish a highly regulated concentration gradient of ions between the two fluids, thereby controlling the composition of CSF. CP plays an important part in healthy brain homeostasis, as its failure to maintain adequate CSF perfusion is implicated in Alzheimer's disease and traumatic brain injury. And yet, the physiology of CP and the mechanism of its age-related functional decline is one of the most understudied areas of neurobiology. Here, we describe a protocol to isolate and identify individual choroid plexus epithelial cells (CPEC) from murine brain for whole-cell patch-clamp recordings and ion channel identification. Using the recording from the inwardly rectifying potassium channel Kir7.1 and TRPM3 that are abundant in CP, we demonstrate a technique to study the regulators of ion channels in the choroid plexus.

Electrokinetic sweeping of colloids at a reactive magnesium oxide interface

Investigating the electrokinetic (EK) response in the vicinity of interfaces has regained interest due to the development of new membrane based processes for energy harvesting or soil depollution. However, the case of reactive interfaces, ubiquitous in these processes, remains scarcely explored. Here we experimentally investigate the EK response of a model interface between an aqueous electrolyte and a bulk MgO crystal surface (100), for different pH. For that purpose, we use a lab-scale non invasive method to monitor the zeta potential of the interface versus time, by confocal fluorescent particle tracking. An unexpected motion of the particles, repelled and then attracted again by the interface is observed. We attributed this motion to the surface reactivity, inducing ion concentration gradients perpendicular to the interface and subsequent diffusiophoresis of the charged particle. Accordingly, we could describe at a semi-quantitative level the particle dynamics by solving numerically the Poisson-Nernst-Planck equations to establish concentration profile in the system and subsequent diffusiophoretic motion. These experiments open the way to the characterization of both the EK response and the reaction rate in the vicinity of reactive interfaces.

Boosting adsorption of heavy metal ions in wastewater through solar-driven interfacial evaporation of chemically-treated carbonized wood

Once the adsorbent is selected, almost introducing larger specific surface area and more surface functional groups becomes the only way to improve its adsorption performance. However, this approach is generally limited in practical application for intricate and costly engineering steps. Herein, we provided a novel avenue for boosting adsorption activities towards specific metal ions in wastewater. Solar-driven interfacial water evaporation produces the localized temperature field and concentration gradient of metal ions inside small pores, endowing with a new sorption mechanism. By using chemically-treated carbonized wood as all-in-one solar absorption and metal ion adsorption system, we achieved higher water evaporation rate and heavy metal ion removal efficiency than carbonization-only wood reported previously. In particular, this system exhibited a strong dependence of specific metal ion adsorption capacity on solar intensity. Pb2+ adsorption capacity was enhanced by over 225% with the solar intensity increased to 3.0 kW·m−2. This could originate from the formed temperature field localized specially on the surface of adsorbents that not only induces Pb2+ concentration gradient near to solid-liquid interface but also activate inactive adsorption sites. Besides, the chemical-treated & carbonized wood showed excellent cyclic stability and can be directly utilized for wastewater treatment, recovery and reuse.

Interface Inversion: A Promising Strategy to Configure Ultrafine Nanoparticles over Graphene for Fast Sodium Storage.

Due to the merits of high activity and rapid reaction kinetics, ultrafine nanoparticles loaded on conductive scaffolds are of great potential in energy-related fields. Usually, the nucleation and uniform growth of these active nanoparticles in high density on scaffolds is governed by the local ion concentration gradient and nucleation sites at the interfaces. On account of this, a novel interface-inverting strategy is developed to modulate the diffusion of metal ions toward the nucleation sites, leading to the tuned growth of ultrafine nanoparticles anchored on graphene. Typically, the Ni(OH)2 deposited on graphene initially enables the interface inverting from oil-water-solid consisting of liquid paraffin (LP), water, and GO to water-oil-solid, finally resulting in LP-enveloped Ni(OH)2 /GO structure. In response, the inert-infiltrated LP layer inhibits the solubility and diffusion of nickel ions, which functions to modulate the growth and aggregation of adjacent nanoparticles. As a demonstration, the phosphorized Ni2 P@C/G as anode in sodium-ion capacitor can deliver a high energy density of 54Wh kg-1 at a high power density of 23kW kg-1 yet with a remarkable rate performance due to the surface-enhanced energy storage and fast Na+ transport enabled by the tuned surface/interface.

Direct Numerical Simulation of Electric Double Layer Formation in Supercapacitors

We will present an innovative method to simulate the formation of electric double layers on complex electrode geometries. Electric double layers are omnipresent and affect the ionic diffusion in many natural systems. It plays the most crucial role in the energy storage of supercapacitors and electric-field desalination. Upon imposing an electrostatic potential, the cations and anions near the electrode surface separate to form a localized polarization counterbalancing the potential. The charge-separated region usually spans 20 to 50 nanometers, whereas other significant length scales, e.g., particle size or inter-particle space in electrodes, are in tens to hundreds of microns. A direct numerical simulation in the continuum scale requires to resolve the ionic concentration and potential gradients across 3~4 orders of magnitude in spatial scales and is incredibly challenging. Therefore, continuum-scale numerical studies are limited to one-dimensional or simple symmetric geometries, or in nanoscales where double-layer thickness and particle size are comparable. In this work, we use the smoothed boundary method that defines complex microstructures with a phase-field-order-parameter-like continuous function to reformulate the Nernst-Planck-Poisson equations and solve the equations on adaptively refined meshes. Thus, the method allows for accurately simulating the charge separation and potential distribution in arbitrarily complex geometries with resolutions spanning from nanometers in the double layer to micron/millimeters in the particle/electrode scales. Simulations of the dynamics during double layer formation and the resultant capacitance on complex electrode microstructures will be presented. The coupling of charge separation and fluid mechanics in simulating the electric-field desalination process through porous electrodes will also be discussed. Figure Caption: Electrostatic potential in the electrolyte of the supercapacitor at different time after simulation begins (a) t = 0.133 ms (b) t = 0.266 ms (c) t = 0.532 ms and (d) t = 2.13 ms. Figure 1

(Invited) Enabling Fast Charging Li-ion Batteries through Three-dimensional Graphite Anode Design

Current Li-ion battery technology is highly optimized for performance at relatively slow charging rates. However, significant challenges still present for fast-charge conditions with < 15-minute charge time.1 In state-of-the-art Li-ion batteries with high energy densities, thick electrodes (> 50 μm) are adopted, which leads to a tradeoff between energy density and high-power performance. Thicker electrodes with tortuous pathways limit Li-ion transport through the electrode thickness, resulting in large electrolyte concentration gradients during cycling. This causes large cell polarizations, which reduce the accessible capacity of the battery. In addition, the electrochemical potential of the graphite anode can become more negative than the thermodynamic potential of Li metal during fast charging, resulting in irreversible Li plating. Therefore, to simultaneously achieve fast charging and maintain energy density of Li-ion batteries, new approaches are required to address Li ionic transport limitations through the thick graphite anodes.In this work, we demonstrate a structural modification of conventional graphite anodes to improve their fast-charge capability. This is achieved by introducing laser-patterned vertical channels into post-calendered graphite anodes.2 This 3-D electrode architecture consists of a hexagonal close-packed array of vertical channels that serve as linear pathways for rapid ionic diffusion through the electrode thickness, allowing for a more homogeneous Li-ion flux throughout the volume of the electrode and decreased ionic concentration gradients. As a result, the accessible capacity of the electrode can be significantly improved and Li plating can be minimized during fast charging. Utilizing the 3-D electrode design, we demonstrate significant improvement in capacity fade at 4C (15-minute) and 6C (10-minute) charge rate with industrial-relevant electrode material and loading (> 3 mAh/cm2 electrode loading in > 2Ah pouch cells). This work thus demonstrates the viability of realizing high energy density Li-ion batteries with fast charge capability based on thick electrodes.Reference Ahmed, S. et al. Enabling fast charging e A battery technology gap assessment. 367, 250–262 (2017).Chen, K.-H; Namkoong, M.; Goel, V.; Yang, C.; Mazumder, J; Thornton, K.; Sakamoto, J; Dasgupta, N. P. Efficient Fast-Charging of Lithium-ion Batteries Enabled by Laser-Patterned Three-Dimensional Graphite Anode Architectures. J. Power Sources In Press (2020).

Characterizing Ion Transport in Non-Aqueous Electrolyte Solutions for Li-Ion and Li- Metal Batteries

A majority of ionic conductivity in current state-of-the-art liquid electrolytes results from the movement of the anion rather than the electrochemically active Li+ ion. Passing current through such an electrolyte can cause severe ionic concentration gradients to extend into porous electrodes, which at high currents can reduce active material utilization and result in high overpotentials that cause deleterious side reactions to occur (e.g., Li plating on graphite electrodes). The severity of these concentration gradients is directly influenced by the transference number (t+), which describes the ratio of current carried by the electrochemically active Li+ ion to the total current passed. Non-aqueous polyelectrolyte solutions (PESs) are a promising, but underexplored, route to high transference number electrolytes that demonstrate potential for both high ionic conductivity and t+. This combination is achieved by anchoring the anion to a polymer backbone – allowing for high t+ by slowing down the motion of the electrochemically inactive anion – while maintaining high ion conductivity through improved ion dissociation and solvent-mediated Li+ transport. New measurement techniques are necessary to rigorously understand ion-transport and structure-property relationships in this new class of electrolytes.Rigorously measuring the complete set of transport properties of concentrated liquid electrolytes under battery-relevant operating conditions is difficult and sparsely explored in experimental liquid electrolyte literature. Complete transport characterization is particularly challenging for novel electrolytes and additives where cost or synthetic complexity limit the volume of available electrolyte. In particular, small volume characterization is necessary for polyelectrolyte solutions, in order to study many different polymer concentrations and molecular weights. Major challenges limiting full ion transport characterization in liquid systems include significant corrosion of Li metal in the presence of electrolyte solvents, large and unstable interfacial impedance, and difficulty in establishing sufficiently small concentration gradients to ensure measurement validity while maintaining high signal to noise ratio data.In this presentation, we will discuss efforts to understand and address these challenges. Using techniques amenable to small electrolyte volumes, we rigorously measured liquid electrolyte transport properties, including the ideal solution Bruce-Vincent transference number, total salt diffusion coefficients, activity coefficients, and the true transference number under battery-relevant conditions using Newman’s concentrated solution theory framework. While our long-term objective is to fully characterize Li-triflimide-appended polyelectrolyte solutions, we initially attempt to develop the methodology on the well-studied liquid electrolyte system of LiPF6 in an ethylene carbonate:ethyl methyl carbonate blend. Using rigorous statistical analysis, we found that transport coefficients obtained via these measurements were consistently not in agreement with those reported in the literature and prone to significant variation depending on data fitting methodology. We believe the discrepancy can largely be attributed to parasitic corrosion reactions and large interfacial resistances at the lithium electrodes, which appear to dominate at the low current densities necessary to maintain sufficiently small concentration gradients. These experimental findings are supported by COMSOL Multiphysics modeling studies. Additional experimental studies incorporating stabilizing additives indicate that simply improving Li stripping/plating coulombic efficiency does not allow for accurate transport coefficient measurements. This reveals a major roadblock in characterizing liquid electrolyte systems, as methods that rely on Li metal stripping/plating do not readily result in reliable liquid electrolyte transport coefficients, unlike similar methods for solid polymer electrolytes. These results have important implications across the electrolyte engineering field that often relies on similar tests to screen electrolyte candidates.