Water-based process for preparation, separation, and recycling of LiCoO2 from Li-ion battery cathodes
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Wygant, Bryan Russell↗
SEARCH · Engineering Papers
Results for “Ions Separations”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Synthesis, crystal structure and magnetic properties of K Ln Se 2 ( Ln = La, Ce, Pr, Nd) structures: A family of 2D triangular lattice frustrated magnets
Here, we report the detail synthesis, single crystal structure characterization and magnetic properties of KLnSe 2 series obtained via solid state molten flux growth method. The crystal structures were characterized using single crystal x-ray diffraction. The KLnSe 2 (Ln = La, Ce, Pr and Nd) series crystallizes in the trigonal crystal system with the space group of R-3m (No. 166). The overall structure contains two-dimensional (2D) layers made from edged shared LnSe 6 -octahedra. Ln 3+ ions form a perfect triangular magnetic lattice which propagates along ab-plane. These triangular lattices are separated by the K + ions. The magnetic properties confirm that, Ce, Pr and Nd do not show any long-range ordering down to 0.4 K indicating frustrated magnetism in the KLnSe 2 series.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Functionalization of Electrodes with Tunable [EMIM] x [Cl] x +1 – Ionic Liquid Clusters for Electrochemical Separations
Functionalization of electrodes with clusters of hydrophobic molecules may improve the energy efficiency and selectivity of electrochemical separations by modulating the desolvation process occurring at the interface. Ionic liquids (IL), which have a broad range of compositions and properties, are potential candidates for controlling the transport, desolvation, and adsorption of target ions at electrochemical interfaces. We report a joint experimental and theoretical investigation of the structure, stability, and selective adsorption properties of the IL clusters 1-ethyl-3-methylimidazolium chloride [EMIM] x [Cl] x+1 - (x = 1 – 10) and demonstrate their ability to adsorb and separate ions from solution. The structure and stability of the IL clusters are determined experimentally using high-mass-resolution electrospray ionization mass spectrometry, collision-induced dissociation, and negative ion photoelectron spectroscopy. Global optimization theory and ab initio molecular dynamics simulations provide molecular-level insight into the bonding and structural fluxionality of these species. Ion soft landing is used to selectively functionalize the surface of highly oriented pyrolytic graphite (HOPG) working electrodes with [EMIM] 1 [Cl] 2 - , [EMIM] 3 [Cl] 4 - , and [EMIM] 5 [Cl] 6 - clusters. Kelvin probe microscopy provides insight into the relative stability of the clusters on HOPG and their effect on the work function of IL-functionalized electrodes. Cyclic voltammetry measurements reveal irreversible adsorption of Fe(CN) 6 4-/3- anions during redox cycling, while electrochemical impedance spectroscopy indicates a substantial decrease in the electron transfer resistance of the IL-functionalized electrodes due to adsorption of Fe(CN) 6 4-/3- . Overall, our findings demonstrate that IL clusters with different size and stoichiometry may be used to increase the efficiency of electrochemical separations, opening new horizons in selective electrode functionalization.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Origin of Unusual Acidity and Li+ Diffusivity in a Series of Water-in-Salt Electrolytes.
Superconcentrated aqueous electrolytes ("water-in-salt" electrolytes, or WiSEs) enable various aqueous battery chemistries beyond the voltage limits imposed by the Pourbaix diagram of water. However, their detailed structural and transport properties remain unexplored and could be better understood through added studies. Here, we report on our observations of strong acidity (pH 2.4) induced by lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) at superconcentration (at 20 mol/kg). Multiple nuclear magnetic resonance (NMR) and pulsed-field gradient (PFG) diffusion NMR experiments, density functional theory (DFT) calculations, and molecular dynamics (MD) simulations reveal that such acidity originates from the formation of nanometric ion-rich structures. The experimental and simulation results indicate the separation of water-rich and ion-rich domains at salt concentrations >= 5 m and the acidity arising therefrom is due to deprotonation of water molecules in the ion-rich domains. As such, the ion-rich domain is composed of hydrophobic -CF3 (of TFSI-) and hydrophilic hydroxyl (OH-) groups. At 20 m concentration, the tortuosity and radius of water diffusion channels are estimated to be similar to 10 and similar to 1 nm, respectively, which are close to values obtained from hydrated Nafion membranes that also have hydrophobic polytetrafluoroethylene (PTFE) backbones and hydrophilic channels consisting of SO3- ion cluster networks providing for the transport of ions and water. Thus, we have discovered the structural similarity between WiSE and hydrated Nafion membranes on the nanometer scale.
Han, Kee Sung↗
Synthesis and structure of Americium(III) diglycolate oxalate Trihydrate, Am(ODA)(C 2 O 4 )(H 2 O) 3
Improving f-element separations is important for actinide(III) (An 3+ ) and lanthanide(III) (Ln 3+ ) based technologies. Unfortunately, An 3+ and Ln 3+ ions are difficult to separate from one another because they have similar chemical characteristics. One successful separation method utilizes anion exchange chromatography. This approach exploits differences in An 3+ and Ln 3+ Lewis acidities and their varying abilities to attract anionic complexing agents, like oxalates (C 2 O 4 2– ) and diglycolates (ODA 2– ). The resulting negatively charged complexes are then separated using an anion exchange resin. To better understand how this anion exchange separation works, we reacted Am 3+ (aq) (aq designates Am 3+ dissolved in water) with the anion exchange complexing agents (H 2 C 2 O 4 and H 2 ODA). Here, the resulting Am(ODA)(C 2 O 4 )(H 2 O) 3 product was characterized using single crystal X-ray diffraction and UV-Vis-NIR spectroscopy. The Am(ODA)(C 2 O 4 )(H 2 O) 3 structure was similar to that established previously for Ln 3+ analogues, namely Ln(ODA)(C 2 O 4 )(H 2 O) x . These compounds were all isomorphous, had bridging C 2 O 4 2– and ODA 2– ligands, and crystallized as 2-dimensional extended solids. In addition, the Am 3 +–O bond distances could be predicted based on relative differences in Am 3+ and Ln 3+ 9-coordinate metal ionic radii. Overall, isolation of Am(ODA)(C 2 O 4 )(H 2 O) 3 showcased similarities in complexation and crystallization chemistry for Am 3+ and Ln 3+ .
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Cost‐Effective and Scalable Approach for the Separation and Direct Cathode Recovery from End‐of‐Life Li‐Ion Batteries
Li-ion battery recycling presents a promising opportunity to decrease dependence on foreign sources of materials and harvest precious materials within the United States. Herein, a superior complete direct recycling process on individual end-of-life cells is reported where the recovered high-purity cathode active material, as well as electrolyte salt Li hexafluorophosphate (LiPF 6 ) can be reused without significant processing. This new process utilizes a series of mechanical separation steps that enable the separation of the cathode and anode active materials while they are still attached to their current collectors. Using this type of process can significantly reduce metal contamination and enable a clean cathode that can be directly recycled. The process if implemented commercially can greatly reduce the environmental burden of batteries as the greenhouse gas emissions of 8.25 kg CO 2 e kg −1 from the direct recycling process are 64% lower compared to those from virgin production of cathode material. During electrochemical testing of the recovered LiNi 0.6 Mn 0.2 Co 0.2 O 2 a discharge capacity of ≈160 mAh g −1 and good cyclability of over 250 cycles at 0.33C are achieved. This success paves a new pathway to explore and optimize existing Li-ion battery recycling procedures.
electrolyte reuse↗
Origins of Enhanced Ion Transport in Nanostructured Anion-Conducting Polyelectrolytes
Ion-conducting polymer chemistry and microstructure profoundly impact membrane water uptake and ionic conductivity. Water uptake strongly impacts ionic conductivity; yet excess water uptake compromises ion-exchange membrane mechanical properties. Although nanophase separation has been proposed to overcome this trade-off, it is unclear how polymer backbone architecture governs ionic nanostructure and its subsequent impact on water uptake and conductivity. Here, we integrate experiments and molecular dynamics simulations to elucidate the role of backbone chemistry in governing ionic nanostructure, hydration behavior, and ion transport in anion-conducting polyelectrolytes (ACPs). We systematically investigate hydrocarbon polynorbornene (PNB)-based ACPs with three distinct backbone architectures: vinyl-addition polymerization (VAP), ring-opening metathesis polymerization (ROMP), and hydrogenated ROMP. While maintaining comparable ion exchange capacities (IECs) and identical side-chain chemistry, we isolate the effects of backbone structure. We show that nanophase-separated ionic nanostructures originate in the dry state and evolve upon hydration through heterogeneous water uptake, with water preferentially partitioning into ion-rich domains. This nanophase separation arises from a delicate interplay between ionic segregation propensity and the entropic barrier imposed by backbone stiffness. Specifically, flexible backbones intensify attractive ion–ion interactions by reducing the entropic penalty for backbone deformation, promoting nanophase separation, while rigid backbones suppress ionic nanostructure formation. Nanophase-separated ion domains locally concentrate water upon hydration, which in turn enables the connectivity required for fast transport at lower water concentration values. Furthermore, these findings demonstrate that backbone chemistry can be tuned as a design lever to promote nanophase separation and enhance ion transport without excessive water uptake.
Anions↗
Porin-Inspired Ionomers with sub-nm Gated Ion Channels for High Ion Conductivity and Selectivity (Final Project Report (2026))
The physiological functions of living systems heavily rely on biological ion channels, whose malfunction can lead to disease. These channels enable selective and regulated transport of water, ions, or small molecules across membranes. Analogously, ionomers used in energy conversion and storage technologies govern ion transport within membrane separators and catalyst binder layers. This DOE Office of Science Early CAREER project aimed to achieve molecular-level control over ionic conductivity and ion permselectivity by translating the functionalities of biological, gated ion channels into a novel class of ion-conducting polymers (ionomers) incorporating macrocyclic calix[4]arene-based repeat units. The overarching goal was to establish fundamental design principles and elucidate proton conduction mechanisms through strategic design of macrocyclic calix[4]arene-containing ionomers, with close relevance to energy conversion and storage devices, including proton exchange membrane fuel cells (PEMFCs). The project leveraged sub-nm-sized macrocyclic pores to facilitate exceptionally fast ion transport (beneficial to addressing sluggish ORR kinetics of PEMFC electrodes) and achieve functionalities of ionic diodes under applied electrochemical fields, beneficial for selective transport/separation.
59 BASIC BIOLOGICAL SCIENCES↗
Ion-Specific Precipitation of Extractants Enables Rare-Earth Separation and Wastewater Remediation from Solvent Extraction of Critical Elements
The increasing demand for rare-earth elements (REEs) necessitates sustainable recovery strategies, particularly from secondary sources, such as electronic waste. Solvent extraction is the primary industrial method for REE separation; however, the unintentional dissolution of extractants into wastewater poses serious environmental risks, leading to organic contamination and process inefficiencies. Existing wastewater treatment methods struggle to remove these persistent pollutants, underscoring the need for innovative recovery approaches. Herein, we present a ligand-mediated precipitation strategy that simultaneously recovers REEs and removes dissolved extractants from solvent extraction wastewater. We show that residual extractants in the aqueous phase can selectively bind REEs, inducing their precipitation while leaving transition metals in solution. By integrating FTIR spectroscopy, EDS, XPS, EXAFS, and SAXS, we elucidate the mechanism of ion-specific precipitation and the local coordination environment of metal ions in the precipitate. Importantly, we demonstrate that the precipitated extractants can be efficiently recovered and reused, providing a closed-loop solution that enhances sustainability. Applying this method to leachates from samarium–cobalt (Sm–Co) and neodymium–iron–boron (NdFeB) mixed magnets, we achieve highly selective REE precipitation under mild conditions, demonstrating a scalable and cost-effective pathway for REE recovery, wastewater purification, and extractant recycling. In conclusion, by integrating element-specific ligand-mediated precipitation with extractant reuse, this work offers a transformative approach to REE separation that reduces the environmental impact while improving resource efficiency.
E-waste↗
Adverse Effects of Trace Non-polar Binder on Ion Transport in Free-standing Sulfide Solid Electrolyte Separators
Sulfide solid-state electrolyte (SE) possesses high room-temperature ionic conductivity. However, fabrication of the free-standing, sheet-type thin sulfide SE film electrolyte to enable all-solid-state batteries to deliver high energy and power density remains challenging. Herein we show that argyrodite sulfide (Li 6 PS 5 Cl) SE can be slurry cast to form free-standing films with low (≤5 wt%) loadings of poly(isobutylene) (PIB) binder. Two factors contribute to a lower areal specific resistance (ASR) of the thin film SEs benchmarked to the pristine powder pellet SSE counterparts: i) 1–2 orders reduced thickness and ii) reasonably comparable ionic conductivity at room temperature after the isostatic pressing process. Nevertheless, an increasing polymer binder loading inevitably introduced voids in the thin film SEs, compromising anode/electrolyte interfacial ion transport. Our findings highlight that electrolyte/electrode interfacial stability, as well as the selection of slurry components, including sulfide SE, binder, and solvent, play essential roles in thin film sulfide electrolyte development.
25 ENERGY STORAGE↗
Nonlinear burn control in ITER using adaptive allocation of actuators with uncertain dynamics
Abstract ITER will be the first tokamak to sustain a fusion-producing, or burning, plasma. If the plasma temperature were to inadvertently rise in this burning regime, the positive correlation between temperature and the fusion reaction rate would establish a destabilizing positive feedback loop. Careful regulation of the plasma’s temperature and density, or burn control, is required to prevent these potentially reactor-damaging thermal excursions, neutralize disturbances and improve performance. In this work, a Lyapunov-based burn controller is designed using a full zero-dimensional nonlinear model. An adaptive estimator manages destabilizing uncertainties in the plasma confinement properties and the particle recycling conditions (caused by plasma–wall interactions). The controller regulates the plasma density with requests for deuterium and tritium particle injections. In ITER-like plasmas, the fusion-born alpha particles will primarily heat the plasma electrons, resulting in different electron and ion temperatures in the core. By considering separate response models for the electron and ion energies, the proposed controller can independently regulate the electron and ion temperatures by requesting that different amounts of auxiliary power be delivered to the electrons and ions. These two commands for a specific control effort (electron and ion heating) are sent to an actuator allocation module that optimally maps them to the heating actuators available to ITER: an electron cyclotron heating system (20 MW), an ion cyclotron heating system (20 MW), and two neutral beam injectors (16.5 MW each). Two different actuator allocators are presented in this work. The first actuator allocator finds the optimal mapping by solving a convex quadratic program that includes actuator saturation and rate limits. It is nonadaptive and assumes that the mapping between the commanded control efforts and the allocated actuators (i.e. the effector model) contains no uncertainties. The second actuator allocation module has an adaptive estimator to handle uncertainties in the effector model. This uncertainty includes actuator efficiencies, the fractions of neutral beam heating that are deposited into the plasma electrons and ions, and the tritium concentration of the fueling pellets. Furthermore, the adaptive allocator considers actuator dynamics (actuation lag) that contain uncertainty. This adaptive allocation algorithm is more computationally efficient than the aforementioned nonadaptive allocator because it is computed using dynamic update laws so that finding the solution to a static optimization problem is not required at every time step. A simulation study assesses the performance of the proposed adaptive burn controller augmented with each of the actuator allocation modules.
Physics↗
Method for the preparation of controlled porosity supports for chromatographic separation
Disclosed herein are extraction chromatographic supports comprising a porous support, an inert filler, and metal ion binding extractant that may be used for chromatographic separation of metal ions. Also disclosed herein are methods for preparing and using the extraction chromatographic supports.
Dietz, Mark↗
Membrane design for non-aqueous redox flow batteries: Current status and path forward
Redox flow batteries are promising technologies for large-scale, long-duration energy storage applications. Among them, non-aqueous redox flow batteries (NARFB) represent a transformative flow battery system since NARFBs potentially offer a higher energy density than aqueous flow batteries. However, many technical challenges remain for NARFBs, including the lack of high-performance membranes, low solubility of redox materials, and poor cycling efficiencies. Membranes serve a vital function in NARFBs, as they allow for selective ion transport while providing separation between the anolyte and catholyte. NARFB membrane development is an emerging research area, and this article reviews their design and critical factors that influence membrane properties, including solvent uptake, ion transport, and redox species permeability. A greater understanding of membrane behavior in non-aqueous solutions provides design principles for developing next-generation membranes for NARFB. In conclusion, we summarize the challenges, target metrics, and future perspectives for NARFBs.
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
Alizarin Multilayers Adsorbed onto Glassy Carbon Electrodes for Electrochemical Sequestration of Manganese, Sodium, and Lithium Cations
The development of efficient methods for metal ion recovery and water remediation is critical for addressing the nation’s urgent need for secure domestic supply chains, overcoming critical materials challenges, and ensuring resilient manufacturing. Here, we present a novel approach for synthesizing stable Alizarin (Alz, 1,2-dihydroxy anthraquinone) multilayers on glassy carbon electrodes (GCEs) for electrochemical sequestration of manganese, sodium, and lithium cations. Alz-GCEs exhibit negatively shifted reduction potentials, indicating strong interactions between Alz and metal cations through metal-coupled electron transfer (MCET) mechanisms. The cation binding interactions and redox behavior of these electrodes were investigated using cyclic voltammetry (CV) and density functional theory (DFT) calculations. Our results demonstrate that Alz forms multilayer structures on GCEs with redox properties that are modulated by the presence of metal cations in the electrolyte. DFT calculations provide insights into the electrochemical mechanism, indicating both stepwise and concerted pathways for metal binding. The findings highlight the potential of Alz-GCEs for efficient and selective metal ion capture, which could be useful for developing sustainable materials for critical metal recovery and water remediation. This work suggests that redox-mediated organic adlayers are promising candidates for advancing electrochemical separation technologies of metal ions.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Self-acceleration and energy channeling in the saturation of the ion-sound instability in a bounded plasma
A novel regime of the saturation of the Pierce-type ion-sound instability in bounded ion-beam-plasma system is revealed in 1D PIC simulations. It is found that the saturation of the instability is mediated by the oscillating virtual anode potential structure. The periodically oscillating potential barrier separates the incoming beam ions into two groups. One component forms a supersonic beam which is accelerated to an energy exceeding the energy of the initial cold ion beam. The other component is organized as a self-consistent phase space structure of trapped ions with a wide energy spread – the ion hole. The effective temperature (energy spread) of the ions trapped in the hole is lower than the initial beam energy. In the final stage the ion hole expands over the whole system length.
70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
Capacitive Deionization for the Extraction and Recovery of Butyrate
Separation processes underpin chemical manufacturing, energy and fuel production, resource recovery, and water purification. Capacitive deionization (CDI) is an electrochemical separation technique based on electrosorption of charged species from an aqueous solution. This work reports the development and application of CDI for the extraction and recovery of butyrate, a carboxylate anion that is key to bioenergy production, among other applications. Electrosorption of sodium butyrate was evaluated using a bench-scale CDI system with activated carbon cloth electrodes. Applying an external potential (1.2 V) enhanced the adsorption capacity of activated carbon for butyrate by 250%. Reversible electrosorption was also demonstrated by extracting and recovering butyrate at 1.2 and 0 V, respectively. Performance metrics including butyrate adsorption and desorption capacities, adsorption and desorption rates, charge efficiency, energy consumption, and recovery are reported. Furthermore, this study also investigates the long-term operational stability of the system by cycling the cell more than 1000 times using 1.2 and 0 V for charging and discharging, respectively. Subsequent physicochemical characterization indicates increased oxygen content (from similar to 2% to >8%), decreased specific surface area (by similar to 20%), and decreased pore volume (by similar to 20%), attributed to carbon oxidation. Overall, this work informs the design of CDI for organic anion separation and recovery.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Novel Separator Membranes for Rechargeable High Energy Density Mg-Ion Batteries
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Shanthi, Pavithra↗
Bicarbonate-Carbonate Selectivity through Nanofiltration for Direct Air Capture of Carbon Dioxide
Direct air capture (DAC) of carbon dioxide is one approach among many proposed that is capable of offsetting hard-to-avoid emissions. In previous work, we developed the alkalinity concentration swing (ACS) method, which is driven through concentrating an alkaline solution that has been loaded with atmospheric CO 2 by desalination technologies, such as reverse osmosis or capacitive deionization. Though the ACS is promising in terms of energy usage and implementation, its absorption rate and water requirements are infeasible for a large-scale DAC process. Here, we propose an improvement on the ACS, the bicarbonate-enriched alkalinity concentration swing (BE-ACS), which selects bicarbonate ions from a stream of aqueous alkaline solution that has absorbed atmospheric CO 2 . The bicarbonate-rich stream is then concentrated, which greatly increases its CO 2 partial pressure, and then CO 2 is extracted from solution. We experimentally investigate the use of pressure-driven nanofiltration (NF) membrane-based separation to select bicarbonate ions over carbonate ions. We screen commercial membranes and select one high-performance membrane for detailed studies, quantifying its bicarbonate-carbonate selectivity factor and bicarbonate-passage factor. Feed pH, the combined concentration of aqueous CO 2 , bicarbonate, and carbonate species (or dissolved inorganic carbon), alkalinity, and permeation flux are systematically varied to study NF separation properties. We find that the selectivity factor, which exceeds 30 times in certain regimes, increases with higher feed pH and higher alkalinity. Lastly, the performance metrics of the selected NF membrane are input into a theoretical BE-ACS cycle analysis, and the required energy input and cycle capacity output are evaluated. Ideal cycle energy is found to be as low as around 250 kJ/mol, with opportunities identified for further decreases through process engineering and forward osmosis energy recovery.
animal feed↗