Bulk Electrolyte Research Articles

1,8‐Diazabicyclo[5.4.0]undec‐7‐ene as Cyclic Ether Electrolyte Polymerization Inhibition for Wide‐Temperature‐Range High‐Rate Lithium‐ion Batteries

Abstract1,3‐Dioxolane (DOL), with its broad liquid phase temperature window and low Li+‐solvent binding energy, stands out as an ideal solvent candidate for the wide‐temperature and high‐rate electrolytes. Unfortunately, DOL is susceptible to undergo ring‐opening polymerization under common lithium salts, which markedly retards the reaction kinetics. This work introduces the organic basic additive 1,8‐Diazabicyclo[5.4.0]undec‐7‐ene (DBU) to effectively suppress the polymerization, thus achieving compatibility between LiFSI, LiDFOB lithium salts, and DOL. Furthermore, density functional theory (DFT) calculations are utilized to elucidate the underlying mechanisms of DOL polymerization and to clarify how DBU inhibits its polymerization. The resulting electrolyte, devoid of polymer chain formation, forms a weak solvation structure rich in anions, which demonstrates rapid ion transport kinetics in the bulk electrolyte and excellent electrochemical stability at the electrolyte–electrode interfaces (EEIs) simultaneously. When applied to the LiFePO4||graphite full cell, it exhibits exceptional wide‐temperature and high‐rate performance, with specific capacities reaching 101.2 mAh g −1 at room temperature (20 C), 36.9 mAh g−1 at −40 °C (0.5 C), and 118.0 mAh g−1 at 60 °C (20 C). This study significantly guides the development of wide‐temperature, high‐rate electrolytes.

Detecting underscreening and generalized Kirkwood transitions in aqueous electrolytes.

We establish the connection between the measured small angle x-ray scattering signal and the charge-charge correlations underlying Kirkwood transitions (KTs) in 1:1, 2:1, and 3:1 aqueous electrolytes. These measurements allow us to obtain underscreening lengths for bulk electrolytes independently verified by theory and simulations. Furthermore, we generalize the concept of KTs beyond those theoretically predicted for 1:1 electrolytes, which involves the inverse screening length, a0, and the inverse periodicity length, Q0. Above the KTs, we find a universal scaling of a0∝c-ζ/3 and Q0 ∝ c1/3 for the studied electrolyte solutions, where ζ is the ionic strength factor.

Tuning solvation behavior within electric double layer via halogenated MXene for reliable lithium metal batteries

Solid electrolyte interphase (SEI)/electrolyte interface is critical in determining the lithium (Li) plating/stripping behavior. The solvation structure of Li-ion is well understood in the bulk electrolyte. Still, the mechanism of how SEI components affect the Li-ion solvation structure and desolvation energy barrier at the SEI/electrolyte interface is still unclear. Herein, Ti3C2 Maxine with single halogenated terminations (−Cl, −Br, −I) are synthesized and used as a model system, because their surface terminations induce a double halide-rich SEI formation (LiF and LiCl/LiBr/LiI). We examine the influence of the interaction strength between different Li halides and Li-ion on coordination number of Li ions and distribution of Li ions within the inner Helmholtz plane (IHP). A solvation sheath with a low solvent coordination number forms near the IHP of the LiBr interphase, improving the kinetics of Li deposition. Accordingly, half-cells utilising Li-carbon fiber/Ti3C2Br2 electrodes exhibit a long lifespan of 12,000 h (1 mA cm−2, 1 mAh cm−2). A pouch cell comprising Li-carbon fiber/Ti3C2Br2 anode and LiFePO4 cathode displays a capacity retention rate of 97 % after 300 cycles even at a low negative to positive electrode capacity ratio of 2.26. Our research provides crucial principles for the design of SEI components in Li metal batteries.

Regulating Zn2+ Migration-Diffusion Behavior by Spontaneous Cascade Optimization Strategy for Long-Life and Low N/P Ratio Zinc Ion Batteries.

Parasitic side reactions and dendrite growth on zinc anodes are formidable issues causing limited lifetime of aqueous zinc ion batteries (ZIBs). Herein, a spontaneous cascade optimization strategy is first proposed to regulate Zn2+ migration-diffusion behavior. Specifically, PAPE@Zn layer with separation-reconstruction properties is constructed in situ on Zn anode. In this layer, well-soluble poly(ethylene oxide) (PEO) can spontaneously separation to bulk electrolyte and weaken the preferential coordination between H2O and Zn2+ to achieve primary optimization. Meanwhile, poor-soluble polymerized-4-acryloylmorpholine (PACMO) is reconstructed on Zn anode as hydrophobic flower-like arrays with abundant zincophilic sites, further guiding the de-solvation and homogeneous diffusion of Zn2+ to achieve the secondary optimization. Cascade optimization effectively regulates Zn2+ migration-diffusion behavior, dendrite growth and side reactions of Zn anode are negligible, and the stability is significantly improved. Consequently, symmetrical cells exhibit stability over 4000 h (1 mA cm-2). PAPE@Zn//NH4 +-V2O5 full cells with a high current density of 15 A g-1 maintains 72.2 % capacity retention for 12000 cycles. Even better, the full cell demonstrates excellent performance of cumulative capacity of 2.33 Ah cm-2 at ultra-low negative/positive (N/P) ratio of 0.6 and a high mass-loading (~17 mg cm-2). The spontaneous cascade optimization strategy provides novel path to achieve high-performance and practical ZIBs.

Disodium Malate Electrolyte Additive Facilitates Dendrite-Free Zinc Anode: Deposition Kinetics and Interface Regulation.

Due to the presence of H2O within the solvated sheath of [Zn(H2O)6]2+ as well as reactive free water in the electrolyte bulk phase, the extended cycling of aqueous zinc-ion batteries (AZIBs) is significantly affected by detrimental side reactions and the growth of Zn dendrites. This study significantly enhances the long-term cycling stability of AZIBs by introducing a small amount of disodium malate (DM) into a 2m ZnSO4 electrolyte solution. DM involvement in the solvation sheath of Zn2+ reduces the desolvation energy of Zn2+, thereby mitigating the corrosion and hydrogen evolution reaction (HER) of the negative electrode surface by [Zn(H2O)6]2+ ions. Additionally, DM adsorption on the zinc surface retards the reduction kinetics of Zn2+ at anode, promoting uniform distribution and predominant deposition on the flat (002) crystal plane, thus reducing dendrite formation. The assembled Zn||Zn symmetric cell exhibits stable cycling for over 500 h at 10mA cm-2 and 5 mAh cm-2. The Zn||VO2 full cells with DM additive exhibits an ultralong cycling lifespan without capacity loss.

Exploring the Impact of In Situ-Formed Solid-Electrolyte Interphase on the Cycling Performance of Aluminum Metal Anodes.

Unwanted processes in metal anode batteries, e.g., non-uniform metal electrodeposition, electrolyte decomposition, and/or short-circuiting, are not fully captured by the electrolyte bulk solvation structure but rather defined by the electrode-electrolyte interface and its changes induced by cycling conditions. Specifically, for aluminum-ion batteries (AIBs), the role of the solid-electrolyte interphase (SEI) on the Al0 electrodeposition mechanism and associated changes during resting or cycling remain unclear. Here, we investigated the current-dependent changes at the electrified aluminum anode/ionic liquid electrolyte interface to reveal the conditions of the SEI formation leading to irreversible cycling in the AIBs. We identified that the mechanism of anode failure depends on the nature of the counter electrode, where the areal capacity and cycling current for Al0 electrodeposition dictates the number of successful cycles. Notwithstanding the differences behind unstable aluminum anode cycling in symmetrical cells and AIBs, the uniform removal of electrochemically inactive SEI components, e.g., oxide-rich or solvent-derived organic-rich interphases, leads to more efficient cycling behavior. These understandings raise the importance of using specific conditioning protocols for efficient cycling of the aluminum anode in conjugation with different cathode materials.

An assessment of electroneutrality implementations for accurate electrochemical ion transport models

During the diffusion and migration of ions in electrolytes, the electrodynamic ion-ion interactions prevent charge separation despite different ionic mobilities, ultimately enforcing electroneutrality in the bulk electrolyte. To model ion transport accurately, a method to enforce electroneutrality must be implemented. In this study, four strategies to implement electroneutrality are discussed and evaluated. The ion distributions that result from a transport model with the different electroneutrality implementations are calculated, considering various electrolytes and sets of electrochemical parameters. The meaningfulness and applicability of each implementation are assessed through spatial charge accumulations, transference numbers, and experimental data from the literature. Combining the electrochemical ion transport models with the electroneutrality constraint for all ions is shown to result in an overdetermined system of equations if the driving forces are calculated under neglection of diffusion potentials. The often-reported model simplification of using the electroneutrality constraint to resolve the transport of one specific species explicitly results in non-physically correct mass transport. A practical approach to precisely describe the measured physicochemical ion movements is obtained by equilibrating spatial charges with the ion conduction for every time step in the ion transport model, which is reasonably applicable to multi-ion systems in three-dimensional frameworks. This comprehensive assessment aims to guide readers in selecting an appropriate electroneutrality implementation framework for ion transport models.

Anion-cation coupled electrolyte additive enhancing the performance of lithium-oxygen batteries

The rational design of electrolyte via introducing additive is an efficient strategy to improve the electrochemical performance of lithium-oxygen batteries (LOBs). In this work, coupling LiCl and Sn(TFSI)2 as the anion-cation electrolyte additive achieved the high-performance of LOBs by promoting the oxygen electrode reactions, regulating the Li+ solvation structure, and inducing the growth of the SEI protective layer. Specifically, Cl− with strong coordination affinity to Li+ could weaken the binding between Li+ and TEGDME solvent molecules, leading to the formation of an anion-dominant Li+ solvation structure, which facilitates the diffusion of Li+ in the electrolyte bulk and electrolyte/electrode interface. On the other hand, Sn2+ can serve as a redox mediator to catalyze ORR on the cathode and participate in the growth of smooth and dense SEI protective layer on Li metal anode surface, thus effectively promoting the oxygen electrode reaction kinetics and suppressing the corrosion of Li anode. As a consequence, the LOBs with coupled LiCl and Sn(TFSI)2 additive exhibited a ultra-high discharge capacity of 21517.1 mA h g−1 and an excellent cycling life of 334 cycles. This work provides a deep understanding for designing efficient electrolyte with additive for LOBs.

Curved surface coupled structural battery composites manufactured by resin transfer molding process: Microstructure and multifunctional performance

To bridge industrial production and lab-scale research, this work demonstrates a technology to manufacture curved surface structural battery composites (CSBCs) that can simultaneously achieve electrochemical energy storage and load-bearing. The curved-surface carbon fiber structural anode and cathode are fabricated by coating the active materials on carbon fiber fabric with a vacuum-bag-assisted technique. The resin transfer molding (RTM) process is conducted to manufacture the coupled CSBCs by infusing bi-continuous phase epoxy resin electrolyte and curing at high temperatures. The microstructure of structural electrodes and CSBCs is characterized by scanning electron microscopy (SEM). Due to good interfacial compatibility between high mechanical strength carbon fiber structural electrode and high ionic conductivity solid polymer electrolyte bulk for load support, the fabricated CSBCs demonstrate a high density of 294 mWh kg−1 based on the whole mass of devices, a tensile strength of 257.4 MPa with Young's modulus of 12.9 GPa and a flexural strength of 194.1 MPa with flexural modulus of 11.1 GPa. In situ electrochemical-mechanical tests further confirm the durability of CSBCs under mechanical loads with a multifunctional efficiency of 1.07, suggesting the effectiveness of the introduced manufacturing techniques for coupled structural battery composites.

The Effect of Electrolyte pH and Impurities on the Stability of Electrolytic Bicarbonate Conversion.

Electrolytic bicarbonate conversion holds the promise to integrate carbon capture directly with electrochemical conversion. Most research has focused on improving the faradaic efficiencies of the system, however, the stability of the system has not been thoroughly addressed. Here, we find that the bulk electrolyte pH has a large effect on the selectivity, where a higher pH results in a lower selectivity. However, the bulk electrolyte pH has no effect on the stability of the system. A decrease in CO selectivity of 30% was observed within the first three hours of operation in an optimized system with 3 M KHCO3 and gap between the membrane and electrode. Single-pass electrolyte experiments at various constant pH values (8.5, 9.0, 9.5, and 10.0), show that only at a pH of 10 the CO selectivity was stable during three hours, reaching a faradaic efficiency toward CO of only 18% as compared to an initial 55% at pH 8.5. Trace metal impurities present in the electrolyte were found to be the cause of the decrease in stability as these deposit on the electrode surface. By complexing the trace metal ions with ethylenediaminetetraacetic acid (EDTA), the metal deposition was avoided and a stable CO selectivity was obtained.

Rational design of epoxy functionalized ionic liquids electrolyte additive for hydrogen-free and dendrite-free aqueous zinc batteries

Despite the high safety and low cost associated with aqueous Zn-ion batteries (ZIBs), uncontrolled Zn dendrite growth and parasitic reactions induced by water significantly diminish their stability. Herein, a new epoxy functionalized ionic liquid, 4-methyl-4-glycidylmorpholin bis[(trifluoromethyl)sulfonyl]imide (MGM[TFSI]), has been developed to mitigate water reactivity for stable ZIBs. It was found that the MGM+ cation disrupts the hydrogen bond network of water, hindering its adsorption on Zn anodes, thereby suppressing water decomposition and enhancing anode stability. Additionally, preferential adsorption of MGM+ cations on the Zn anode surface mitigates tip effects, suppresses dendrite growth, and promotes the formation of a ZnF2 solid electrolyte interphase layer, effectively isolating the anode from the bulk electrolyte. As a result, benefiting from the well-designed MGM+-based electrolyte, Zn//Zn cells achieve significantly enhanced cycling stability, lasting over 2000 h at 1 mA cm−2 with 1 mAh cm−2. Furthermore, Zn//MnO2 full cells deliver remarkable stability, retaining approximately 89 % of their initial capacity after 3000 cycles at 5 A/g. This work proposes that the MGM[TFSI] additive can effectively regulate the interfacial chemistry of the Zn anode, providing an opportunity to design advanced electrolytes for highly reversible ZIBs and beyond.

Breunnerite grain and magnesium isotope chemistry reveal cation partitioning during aqueous alteration of asteroid Ryugu

Returned samples from the carbonaceous asteroid (162173) Ryugu provide pristine information on the original aqueous alteration history of the Solar System. Secondary precipitates, such as carbonates and phyllosilicates, reveal elemental partitioning of the major component ions linked to the primordial brine composition of the asteroid. Here, we report on the elemental partitioning and Mg isotopic composition (25Mg/24Mg) of breunnerite [(Mg, Fe, Mn)CO3] from the Ryugu C0002 sample and the A0106 and C0107 aggregates by sequential leaching extraction of salts, exchangeable ions, carbonates, and silicates. Breunnerite was the sample most enriched in light Mg isotopes, and the 25Mg/24Mg value of the fluid had shifted lower by ~0.38‰ than the initial value (set to 0‰) before dolomite precipitation. As a simple model, the Mg2+ first precipitated in phyllosilicates, followed by dolomite precipitation, at which time ~76−87% of Mg2+ had been removed from the primordial brine. A minor amount of phyllosilicate precipitation continued after dolomite precipitation. The element composition profiles of the latest solution that interacted with the cation exchange pool of Ryugu were predominantly Na-rich. Na+ acts as a bulk electrolyte and contributes to the stabilization of the negative surface charge of phyllosilicates and organic matter on Ryugu.

Anode‐Electrolyte Interfacial Acidity Regulation Enhances Electrocatalytic Performances of Alcohol Oxidations

AbstractThe local acidity at the anode surface during electrolysis is apparently stronger than that in bulk electrolyte due to the deprotonation from the reactant, which leads to the deteriorated electrocatalytic performances and product distributions. Here, an anode‐electrolyte interfacial acidity regulation strategy has been proposed to inhibit local acidification at the surface of anode and enhance the electrocatalytic activity and selectivity of anodic reactions. As a proof of the concept, CeO2‐x Lewis acid component has been employed as a supporter to load Au nanoparticles to accelerate the diffusion and enrichment of OH− toward the anode surface, so as to accelerate the electrocatalytic alcohol oxidation reaction. As the result, Au/CeO2‐x exhibits much enhanced lactic acid selectivity of 81 % and electrochemical activity of 693 mA⋅cm−2 current density in glycerol oxidation reaction compared to pure Au. Mechanism investigation reveals that the introduced Lewis acid promotes the mass transport and concentration of OH− on the anode surface, thus promoting the generation of lactic acid through the simultaneous enhancements of Faradaic and non‐Faradaic processes. Attractively, the proposed strategy can be used for the electro‐oxidation performance enhancements of a variety of alcohols, which thereby provides a new perspective for efficient alcohol electro‐oxidations and the corresponding electrocatalyst design.

Mass Transport in Confined Micro Geometry in Reciprocating Paddle Plating Cell by Numerical Simulation and Neural Network Analysis

The mass transport in confined geometry in a paddle plating cell is studied using numerical simulation with an attempt to extrapolate an explicit correlation to understand the transport physics and to predict the electrodeposition rate of metal microstructures. A moving boundary in conjunction with mapped mesh is used to allow the reciprocating movement of the flow. A correlation is obtained based on a generalized additive model using multivariant linear regression. Neural networks are also used to analyze the efficacy of such correlation and to determine the descriptor characterizing the error in prediction. A two-step convectional mass transport process, one in the bulk electrolyte outside the patterns and the other inside the micro-trenches, is demonstrated to better describe the overall transport physics and improve the correlation.

Anode-Electrolyte Interfacial Acidity Regulation Enhances Electrocatalytic Performances of Alcohol Oxidations.

The local acidity at the anode surface during electrolysis is apparently stronger than that in bulk electrolyte due to the deprotonation from the reactant, which leads to the deteriorated electrocatalytic performances and product distributions. Here, an anode-electrolyte interfacial acidity regulation strategy has been proposed to inhibit local acidification at the surface of anode and enhance the electrocatalytic activity and selectivity of anodic reactions. As a proof of the concept, CeO2-x Lewis acid component has been employed as a supporter to load Au nanoparticles to accelerate the diffusion and enrichment of OH- toward the anode surface, so as to accelerate the electrocatalytic alcohol oxidation reaction. As the result, Au/CeO2-x exhibits much enhanced lactic acid selectivity of 81 % and electrochemical activity of 693 mA⋅cm-2 current density in glycerol oxidation reaction compared to pure Au. Mechanism investigation reveals that the introduced Lewis acid promotes the mass transport and concentration of OH- on the anode surface, thus promoting the generation of lactic acid through the simultaneous enhancements of Faradaic and non-Faradaic processes. Attractively, the proposed strategy can be used for the electro-oxidation performance enhancements of a variety of alcohols, which thereby provides a new perspective for efficient alcohol electro-oxidations and the corresponding electrocatalyst design.

Tissue-like interfacing of planar electrochemical organic neuromorphic devices

Abstract Electrochemical organic neuromorphic devices (ENODes) are rapidly developing as platforms for computing, automation, and biointerfacing. Resembling short- and long-term synaptic plasticity is a key characteristic in creating functional neuromorphic interfaces that showcase spiking activity and learning capabilities. This potentially enables ENODes to couple with biological systems, such as living neuronal cells and ultimately the brain. Before coupling ENODes with the brain, it is worth investigating the neuromorphic behavior of ENODes when they interface with electrolytes that have a consistency similar to brain tissue in mechanical properties, as this can affect the modulation of ion and neurotransmitter diffusion. Here, we present ENODEs based on different PEDOT:PSS formulations with various geometries interfacing with gel-electrolytes loaded with a neurotransmitter to mimic brain-chip interfacing. Short-term plasticity and neurotransmitter-mediated long-term plasticity have been characterized in contact with diverse gel electrolytes. We found that both the composition of the electrolyte and the PEDOT:PSS formulation used as gate and channel material play a crucial role in the diffusion and trapping of cations that ultimately modulate the conductance of the transistor channels. It was shown that paired pulse facilitation can be achieved in both devices, while long-term plasticity can be achieved with a tissue-like soft electrolyte, such as agarose gel electrolyte, on spin-coated ENODes. Our work on ENODe-gel coupling could pave the way for effective brain interfacing for computing and neuroelectronic applications.

Ammonium crossover as a function of membrane type and operating conditions in flow cells for ammonia synthesis and water treatment applications

AbstractElectrochemical flow cells are promising designs for both ammonium () electrosynthesis from dinitrogen and removal/recovery from wastewater. The crossover is undesirable for electrosynthesis but is favourable for removal. The crossover is investigated herein under different current densities, concentrations, and feed locations using cation‐exchange (Nafion N112, N350) and anion‐exchange (Sustainion X37‐50) membranes and microporous diaphragms (Celgard 3400, 3500, and 5550). For Nafion N112, the crossover from catholyte to anolyte decreases with higher concentrations from 81.9 ± 4.7% at 1 ppm to 10.7 ± 0.7% at 3400 ppm. At a constant concentration, increasing the current density leads to more intense electrolyte pH polarization, which leads to volatilization in favour of recovery up to 78.1 ± 1.1% at a cathode superficial current density of −10 A m−2. When comparing the recovery efficiency, the cathode‐ and symmetric fed operations were outperformed by the anode‐fed mode for 3400 ppm due to the equilibrium that buffers the pH change. For Celgard diaphragms, modest crossover (<5%) was only demonstrated at low current densities (≤−1 A m−2), but the separation was compromised by the bulk electrolyte transport through micropores and electrolysis‐induced pH polarization, highlighting future needs to develop and rigorously verify separators toward electrosynthesis.

Combined electroosmotic and pressure driven flow through soft nanochannel grafted with partially ion-penetrable polyelectrolyte layers

ABSTRACT This study explores the coupled effects of pressure-driven and electroosmotic flows in a soft nanochannel filled with non-Newtonian ionised liquid, where the inner walls are coated with a polymer layer. The ion partitioning effect occurs due to the Born energy, arising from the dielectric permittivity difference between the polyelectrolyte medium and the ionised liquid. The model incorporates the nonlinear Poisson-Boltzmann equation, the modified Darcy-Brinkman equation in the polyelectrolyte layer (PEL), the Cauchy momentum equation in the electrolyte domains and the continuity equation for incompressible fluids. Using the Debye-Hückel approximation for analytical results, the study validates numerical findings. The study considers the no-slip boundary condition on the walls and examines the impact of volume charge density of PEL, bulk electrolyte concentration, non-Newtonian fluid rheology and polymer layer characteristics and applied pressure gradient on flow modulation and ionic transport in the nanochannel. We provide rigorous mathematical results showing how electrohydrodynamic factors like charged PEL, flow behaviour index, EDL thickness, ion partitioning parameters, Debye-Hückel parameter and softness parameters influence the strength of the potential and the total flow modulation. We illustrate ion selectivity in the soft nanochannel and the friction factor across its walls, considering ion partitioning effects.

20-Fold Increased Limiting Currents in Oxygen Reduction with Cu-tmpa by Replacing Flow-By with Flow-Through Electrodes.

Electrochemical oxygen reduction is a promising and sustainable alternative to the current industrial production method for hydrogen peroxide (H2O2), which is a green oxidant in many (emerging) applications in the chemical industry, water treatment, and fuel cells. Low solubility of O2 in water causes severe mass transfer limitations and loss of H2O2 selectivity at industrially relevant current densities, complicating the development of practical-scale electrochemical H2O2 synthesis systems. We tested a flow-by and flow-through configuration and suspension electrodes in an electrochemical flow cell to investigate the influence of electrode configuration and flow conditions on mass transfer and H2O2 production. We monitored the H2O2 production using Cu-tmpa (tmpa = tris(2-pyridylmethyl)amine) as a homogeneous copper-based catalyst in a pH-neutral phosphate buffer during 1 h of catalysis and estimated the limiting current density from CV scans. We achieve the highest H2O2 production and a 15-20 times higher geometrical limiting current density in the flow-through configuration compared to the flow-by configuration due to the increased surface area and foam structure that improved mass transfer. The activated carbon (AC) material in suspension electrodes, which have an even larger surface area, decomposes all produced H2O2 and proves unsuitable for H2O2 synthesis. Although the mass transfer limitations seem to be alleviated on the microscale in the flow-through system, the high O2 consumption and H2O2 production cause challenges in maintaining the initially reached current density and Faradaic efficiency (FE). The decreasing ratio between the concentrations of the O2 and H2O2 in the bulk electrolyte will likely pose a challenge when proceeding to larger systems with longer electrodes. Tuning the reactor design and operating conditions will be essential in maximizing the FE and current density.

(Invited) Analysis of Interfacial Species at Finite Bias - Calcium Borohydride in Tetrahydrofuran

To understand the operation of complex electrolytes we must determine which species are present and active at the interface with the electrode. We combine molecular dynamics sampling with continuum modeling to determine the speciation of Ca(BH4)2 in THF next to a model electrode (graphite). Mulitvalent ions in organic solvents with poor dielectric screening may exist in multiple coordinated states. We explore the free energy landscape associated with the interconversion of species in the bulk electrolyte using metadynamics simulations. We find that the chemical equilibrium between neutral and charged species is dominated by disproportionation following dimer formation - consistent with experimental findings. We also make use of clustering analysis to reveal distinct molecular conformations within constrained coordination states. To assess how the chemical equilibrium may be modified by the potential difference at the electrode, we develop a continuum model based on the modified Poisson-Boltzmann equation, with volume exclusion. This model also incorporates molecular-scale details through sampled free energy profiles of each relevant species within the solvent as a function of distance from the electrode. We find that a narrow (approximately 1 nm) region near the electrode, with highly variable speciation driven by potential difference, dominates the electrochemical activity of this electrolyte.