LiCl Solutions Research Articles

Water-aerosol-assisted roasting for selective lithium extraction from spent lithium-ion batteries

Selective extraction of lithium from spent lithium-ion batteries (LIBs) represents a promising solution for efficient lithium recovery. Herein, a water-aerosol-assisted roasting technology is proposed to selectively extract lithium from spent lithium transition metal oxides (LTMOs) cathodes. In an exemplary recycling of spent LiCoO2, the cathode material undergoes a low-temperature (350°C) chlorinating roast process to convert it into metal chlorides, followed by a higher-temperature (500°C) roasting to facilitate the selective pyrolysis of CoCl2. The presence of water-aerosol significantly enhances the selective pyrolysis process of CoCl2, reducing roasting time eightfold compared to conventional air roasting. Subsequent water-leaching effectively extracts 99.1 % of lithium as LiCl, while only 0.2 % of cobalt is extracted, ensuring selective lithium recovery. The resulting high-purity LiCl solution and Co3O4 residue are directly utilizable for producing battery-grade Li2CO3 and LiCoO2, respectively. Regenerated LiCoO2 demonstrates excellent cycling stability, retaining 90.5 % of its capacity after 300 cycles at 1C rate. Moreover, this method is applicable to ternary cathodes (NCM) black mass, offering a sustainable, robust, and cost-effective approach for lithium extraction from spent LIBs.

Multi-hierarchical structured PTFE membrane for liquid desiccant dewatering via membrane distillation

Poly (tetrafluoroethylene) (PTFE) can be used for robust separation membranes owing to its exceptional chemical and thermal stabilities. Simultaneously achieving construction of hierarchical pore structures and re-entrant surface microstructures during the fabrication of PTFE membrane holds significant importance in addressing the issues of low flux and membrane wetting in membrane distillation (MD). Herein, we proposed a flexible method for manufacturing hierarchically structured PTFE membrane by combining electrospinning/spraying with sintering/welding. The present approach facilitated the controlled fabrication of a superhydrophobic PTFE membrane with slippery surface (exhibiting a water contact angle of 153.5°, and an ultralow sliding angle of 7.5°) without using fluoride-based solvents or external nanoparticles. Moreover, the anti-wetting mechanism and performance stability of the PTFE membranes in MD were thoroughly investigated. In liquid desiccant regeneration experiments, the 20 wt% LiCl solution was successfully concentrated to 28.64 wt%. Furthermore, the PTFE membrane demonstrated a stable flux (>30 kg m−2 h−1) and relatively low permeate conductivity (<15 μs cm−1) during treating simulated seawater for 30 h. The present work offers a new approach to fabricate multi-hierarchical structured superhydrophobic membranes for desalination and regeneration of liquid desiccants.

Preparation, Characterization, and Adsorption Performance of H2TiO3 Lithium Ion Sieves with Homogeneous Nanoparticles: Kinetics, Thermodynamics, and Mechanism Analysis

AbstractLi2TiO3 precursor with layered structure is successfully prepared by template‐free method using anatase TiO2 and Li2CO3, followed by the treatment of dilute hydrochloric acid, which leads to obtaining H2TiO3 lithium ion sieve nanoparticles with uniform dispersion and small size. The adsorption performance and mechanism of the H2TiO3 are being studied. The experimental results show that the H2TiO3 lithium ion sieve has a large BET specific surface area (19.10 m2 g−1) and good thermal stability. At the same time, it also has a high adsorption rate and adsorption capacity (55.13 mg g−1) towards Li+ in solution due to its high dispersibility and uniformity of particle size, which can expose more adsorption sites in LiCl solution. The adsorption capacity of the H2TiO3 lithium ion sieve can reach 46.63 mg g−1, which achieves 84.58% of the equilibrium adsorption capacity. The equilibrium adsorption parameters follow the Langmuir model perfectly, demonstrating that Li+ undergoes monolayer adsorption. The results of thermodynamic and kinetic analysis show that the adsorption behavior of H2TiO3 is spontaneous and conforms to the pseudo‐second‐order kinetic model, indicating the adsorption process is controlled by chemosorption. In addition, after five adsorption/desorption cycles, the H2TiO3 lithium ion sieve still shows a high adsorption capacity of 46.15 mg g−1, and the dissolution loss of titanium is only 0.14%, which shows that the cycle stability is excellent. XPS and zeta potential analyses illustrate that the adsorption mechanism of Li+ on the H2TiO3 is an ion exchange reaction between Li+ and H+, combined with the electrostatic attraction of the adsorbent surface. Additionally, the adsorption performance of H2TiO3 lithium ion sieve in West Taijinaier Salt Lake brine was tested, and the adsorbent material proves itself is a perspective candidate for lithium extraction from aqueous lithium resources.

Research on gas-liquid interface parameters related to thermal performance of frost-free evaporator of air source heat pump

Direct spray frost-free air source heat pumps (FFASHPs) base on liquid desiccant solutions are a more promising renewable energy technology for developing net-zero emission buildings. In order to improve the thermal performance of the frost-free evaporator, a numerical mode was established based on the penetration theory and the two-film theory to reveal the interfacial heat and mass transfer mechanism of LiCl solution falling film absorption on the air side of the frost-free evaporator. The distribution characteristics of temperature, water vapor concentration, effective diffusion coefficient, morphology, velocity and pressure at the interface under different air Reynolds numbers and temperatures were analyzed. The results show that the distribution uniformity of interface parameters has a greater effect on heat transfer performance than its average value. The critical Reynolds number is 391.0 under the present study, and the distribution uniformity of interface parameters and the intensity of interface fluctuation are improved, and the thermal performance reaches the peak. The COP of FFASHP system can be improved effectively when the frost-free evaporator is operated under the critical condition matching its parameters. The purpose of the study is to provide theoretical support for the performance improvement and efficient operation of frost-free evaporators.

Swelling and Degrafting of Poly(3-sulfopropyl methacrylate) Brushes.

Upon exposure to a good solvent, polymer brushes prepared via surface-initiated polymerization can undergo degrafting via cleavage of bonds that anchor the polymer tethers to the underlying substrate. As polymer brushes are often used in a solvent swollen state, this has implications for the longevity of these polymer coatings. Improving the fundamental understanding of this process is thus also of practical importance. It is believed that degrafting is the consequence of tension amplification at the bonds that anchor the polymer grafts, which is driven by swelling of the polymer brush film. Taking advantage of the sensitivity of the swelling behavior of poly(3-sulfopropyl methacrylate) (PSPMA) brushes toward changes in ionic strength, this study has investigated the degrafting behavior of these brushes in aqueous media at different LiCl and NaCl concentrations. The aim of these experiments was to investigate whether the rate constant of the degrafting process was correlated with the swelling ratio of the PSPMA brushes. The experiments show that in aqueous LiCl solutions, the initial rate constant of the degrafting process is correlated with the swelling ratio of the PSPMA brush. This observation represents a first example of the correlation between these two parameters for hydrophilic polymer brushes in aqueous media and supports the idea that degrafting is a mechanochemical process driven by a swelling-induced tension at the polymer-substrate interface.

Electrochemical Relithiation in Spent LiFePO4 Slurry for Regeneration of Lithium-Ion Battery Cathode.

Recycling spent lithium-ion batteries (LIBs) in a green and economical way is vital for maintaining the sustainability of the LIB industry. However, given the low content of high-value components in olivine-type lithium iron phosphate (LFP), traditional metallurgical processes are economically unfeasible for recycling due to high chemical/energy consumption and labor-intensive procedures. This study proposes a facile electrochemistry strategy to directly regenerate the spent LFP material by an electrically driven lithiation process as a spent LFP slurry (200 g/L) rather than as electrodes. Minimal energy and chemical consumption are achieved by enabling the healing of spent LFP without destroying the original olivine-type crystal structure. The proposed method utilizes mild healing conditions (25 °C for 2 h) and LiCl solution as the only reagent in the regeneration process, significantly lowering the expenses associated with producing cathode electrodes. The electrochemical performance of the regenerated LFP have been dramatically recovered after regeneration, exhibiting a capacity of 151.5 mA h g-1 at 0.1 C and 96.6% capacity retention over 400 cycles at 1 C. This approach demonstrates a high processing capability and offers considerable economic and environmental benefits, making it an eco-friendly option and supporting the sustainable development of the LFP industry.

Photothermal-enhanced ion transport for efficient electrochemical lithium extraction at low temperatures

The demand for lithium (Li) resources is booming due to the widespread applications of Li-ion batteries recently. Electrochemically extracting lithium from brines is a promising approach to address the shortage of Li resources. However, when working at low temperatures, which are inevitable in frigid salt lakes, the performance is severely deteriorated due to depressed transport kinetics. Herein, we addressed this issue by constructing a new electrochemical lithium extraction system using polypyrrole-coated FePO4 as the electrode material, which exhibits superior performance at low temperatures due to photothermal effect of polypyrrole. At an ambient temperature of 5 °C and irradiated with sunlight, this system achieved a lithium intercalation capacity of 5.84 mmol g−1 (2.72 times higher than that without solar irradiation) at an extraction rate of 5.92 mmol g−1 h−1 from a 15 mM LiCl solution, and a selectivity of 124 towards Li over Mg. After 5000 cycles of continuous operation, the system still retained 81 % of its initial capacity at a current density of 50 A m−2. The proposed photothermal-enhanced electrochemical lithium extraction system has great application potential for lithium extraction from brine at low-temperature regions.

Early Events in G-quadruplex Folding Captured by Time-Resolved Small-Angle X-Ray Scattering.

Time-resolved small-angle X-ray experiments (TR-SAXS) are reported here that capture and quantify a previously unknown rapid collapse of the unfolded oligonucleotide as an early step in G4 folding of hybrid 1 and hybrid 2 telomeric G-quadruplex structures. The rapid collapse, initiated by a pH jump, is characterized by an exponential decrease in the radius of gyration from 20.6 to 12.6 Å. The collapse is monophasic and is complete in less than 600 ms. Additional hand-mixing pH-jump kinetic studies show that slower kinetic steps follow the collapse. The folded and unfolded states at equilibrium were further characterized by SAXS studies and other biophysical tools, to show that G4 unfolding was complete at alkaline pH, but not in LiCl solution as is often claimed. The SAXS Ensemble Optimization Method (EOM) analysis reveals models of the unfolded state as a dynamic ensemble of flexible oligonucleotide chains with a variety of transient hairpin structures. These results suggest a G4 folding pathway in which a rapid collapse, analogous to molten globule formation seen in proteins, is followed by a confined conformational search within the collapsed particle to form the native contacts ultimately found in the stable folded form.

Hydrophilic surface-modified titanium-based lithium ion sieve adsorbents for efficient lithium extraction

Titanium-based lithium ion sieve adsorbents (HTOs) are considered among the most promising materials for lithium extraction from aqueous sources. In this study, four surfactants—sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), hydroxypropyl cellulose (HPC), and tannic acid (TA)—were used to surface-etch HTOs, preparing adsorbents with enhanced hydrophilicity at the nanoscale. Correlation studies between the hydrophilicity of the HTO-X and their adsorption performance revealed that all HTO-X had lower contact angles than the unetched counterparts, indicating improved adsorption capacities. Notably, TA plays a synergistic role of “killing two birds with one stone”. The TA-etched HTO-T adsorbent exhibited the lowest contact angle (8.8°) and the highest specific surface area (62.10 m2/g). In a LiCl solution, HTO-T’s adsorption capacity for Li+ reached 33.61 mg/g, a 26 % increase over the unetched HTO adsorbent (26.56 mg/g). Simultaneously, HTO-T significantly reduces the adsorption time and enhances the adsorption efficiency during the surface diffusion phase. Additionally, HTO-T demonstrated remarkable selectivity for lithium ions, with separation factors α(Li/Na), α(Li/K), α(Li/Mg), and α(Li/Ca) of 397.13, 181.55, 1288.47, and 1345.19, respectively, showcasing an excellent separation effect. The adsorption mechanism indicates that Li+ adsorption by HTO-T primarily occurs through the disruption of O–H bonds and the formation of new O-Li bonds. This research presents an efficient strategy for the development of HTOs, demonstrating HTO-T as a potential adsorbent for lithium recovery from brine sources.

Enhancement of power density and hydrogen productivity of the reverse electrodialysis process by optimizing the temperature gradient between the working solutions

Reverse electrodialysis (RED) is an emerging technology that converts the salinity gradient energy (SGE) embedded in two solutions of different concentrations into electricity or hydrogen productivity. Given that two solutions containing SGE in nature are often at different temperatures, this study experimentally investigated the effects of the temperature and salinity ratio of the working solutions on the performance of RED systems. The results show that the power density and hydrogen productivity of RED systems could be markedly improved by adjusting the imposed temperature difference on the basis of the salinity gradient. The degree of improvement mainly depends on the magnitude and direction of the temperature difference between the high- and low-concentration solutions. The enhancement effect was more pronounced under a negative temperature difference (NTD) than under a positive temperature difference (PTD). Additionally, the improvement in system performance owing to the temperature difference was not affected by the endothermic or exothermic effects of different solutes in the water. At a NTD of 25℃ and a concentration of 0.1 M aqueous NaOH as the electrode solution, a RED system based on LiBr solution with a salinity ratio of 4.5 M/0.02 M as the working solution achieved a maximum power density of 0.754 ± 0.006 W∙m−2 and the highest hydrogen productivity of 1.128 ± 0.019 mol∙m−2∙h−1, which was 15.1% and 5.5% higher than the hydrogen productivity under LiCl and NaCl solution conditions, respectively. These results show the great potential of LiBr solution in the field of RED hydrogen productivity.

Configuring a structure self-curable lithium aluminum layered double hydroxide chloride type lithium adsorbents via a facile one-pot synergistical modification way

Taking the application merits and difficulty into consideration, a synergistical synchronous doping strategy was firstly proposed for configuring a structure stable high-performance lithium aluminum layered double hydroxide chloride type lithium adsorbents by a simple one-pot precipitation method to resist the performance attenuation of aluminum-based adsorbents during sorption. As-proposed designing strategy not only grants the LDHs-type adsorbents high adsorption capacity up to 10.4 mg/g in 400 ppm LiCl solution, but also ensures the adsorbents excellent Li+/Na+, Li+/Mg2+, Li+/K+ separation coefficients up to 236.7, 187.2 and 282.6, respectively. The initial and retained adsorption capacities after 70 desorption/adsorption cycles of as-prepared adsorbents after granulation are 12.08 and 5.09 mg/g, respectively in real sulfate-type West Taijinar Salt Lake brines with 400 ppm Li+, which is mainly attributed to the largely accelerated structure self-curability at sorption. Generally, this study can actually achieve efficient, selective and stable collection of Li+ from low-grade brines with high Mg2+/Li+ ratio.

Preparation of zirconium oxide surface-modified magnetic lithium-ion sieves and selectivity mechanism analysis for lithium extraction from salt-lake brine based on the first principle

The increasing need for lithium (Li) resources requires the creation of effective extraction methods. Lithium-ion sieves have shown promise as adsorption materials; however, their ultrafine powder properties and poor cycle performance limit their industrial application. In this study, a new lithium-ion sieve named ZrO2@HMFO, which consists of zirconium oxide-coated magnetic manganese (Mn), was investigated. The absorption and desorption of Li by ZrO2@HMFO in a LiCl solution were studied. The adsorption capacity of ZrO2@HMFO was 35.8 mg/g, and it led to a decrease in the dissolution of manganese (Mn) and iron (Fe) to 1.11 % and 0.49 %, respectively. The combination of metal cation doping and coating significantly reduces the dissolution loss of Mn. Density functional theory (DFT) was employed to analyze the mechanism of selective Li+ extraction. Analysis of hydration energy, migration energy barrier, and adsorption energy revealed that Li ions were the most selectively adsorbed. Additionally, the increase in selectivity was confirmed by calculating that Fe doping increases the energy required for other metal cations to replace Hydrogen ions (H+) or Lithium ions (Li+). Thus, ZrO2@HMFO allows for easy separation and stable circulation, making it a promising material for efficient Li+ separation in salt-lake brine. The study of the selectivity mechanism also provides theoretical guidance for improving the selectivity of lithium-ion sieves in future research.

Coupled Electron- and Ion-Transfer Processes at a Liquid/Liquid Interface Decorated with Photoactive Nanomaterials.

The influence of the ion transfer on photoinduced electron transfer (ET) reactions was studied on the surface of hyperbranched semiconducting BiVO4 particles spontaneously adsorbed at the liquid-liquid (L/L) interface between an aqueous LiCl solution and bis(triphenylphosphoranylidene) ammonium tetrakis(pentaflurophenyl)borate (BATB) in 1,2-dichlorethane. The organic electrolyte was supplemented with [Co(bpy)3](PF6)3 to accept photoexcited electrons from BiVO4 under formation of the corresponding Co(II) complex. The L/L interface was stabilized at the orifice of a micropipette (MP) and allowed to record ion transfer cyclic voltammetry (ITCV) by applying a Galvani potential difference between two reference electrodes in the electrolyte solutions with intermittent illumination by visible light (λ>420 nm). The photogenerated holes caused oxidation of water to O2. Co(II) and O2 were detected at constant at an amperometric microelectrode (ME) facing the orifice of the MP in either the organic or the aqueous electrolyte. The overall current exhibits a photocurrent only in the -range, in which the IT of PF6 - is kinetically limited. The amperometric detection of photogenerated products followed the same pattern as the photocurrent in the total current.

Coupled Electron‐ and Ion‐Transfer Processes at a Liquid/Liquid Interface Decorated with Photoactive Nanomaterials

AbstractThe influence of the ion transfer on photoinduced electron transfer (ET) reactions was studied on the surface of hyperbranched semiconducting BiVO4 particles spontaneously adsorbed at the liquid‐liquid (L/L) interface between an aqueous LiCl solution and bis(triphenylphosphoranylidene) ammonium tetrakis(pentaflurophenyl)borate (BATB) in 1,2‐dichlorethane. The organic electrolyte was supplemented with [Co(bpy)3](PF6)3 to accept photoexcited electrons from BiVO4 under formation of the corresponding Co(II) complex. The L/L interface was stabilized at the orifice of a micropipette (MP) and allowed to record ion transfer cyclic voltammetry (ITCV) by applying a Galvani potential difference between two reference electrodes in the electrolyte solutions with intermittent illumination by visible light (λ&gt;420 nm). The photogenerated holes caused oxidation of water to O2. Co(II) and O2 were detected at constant at an amperometric microelectrode (ME) facing the orifice of the MP in either the organic or the aqueous electrolyte. The overall current exhibits a photocurrent only in the ‐range, in which the IT of PF6− is kinetically limited. The amperometric detection of photogenerated products followed the same pattern as the photocurrent in the total current.

Preparation of tungsten-doped Ti-based lithium ion sieves with excellent adsorption performance by hydrothermal method

Ti-based Li-ion sieve (H2TiO3, HTO), is attractive for adsorbing lithium from salt lakes. Nevertheless, the titanium dissolution and limited adsorption capacity affect the cycling stability and adsorption performance. In this work, an atom engineering technique was employed by doping tungsten (W) into layered HTO via a hydrothermal method. Through experiments and theoretical simulation, it was demonstrated that the doped W in HTO results in expanded interplanar spacing, increased surface adsorption energy, and excellent adsorption performance. The optimized HTO-W exhibits an Ti dissolution rate of 0.73 % (in 2 mol L−1 HCl for 12 h, 5.6 % that of pristine HTO) and adsorption capacity of 43.01 mg g−1 (in 425 mg L−1 LiCl solution at 30 °C, 1.4 times that of undoped HTO). Furthermore, the HTO-W reaches adsorption equilibrium in about 3 h with exceptional selectivity and stability. This work demonstrates an effective enhancement of lithium adsorption by W doping, providing new avenues for developing lithium adsorbents with high performance.

Investigating Cathode Dynamics in Realistic Desalination Reactors Using Operando High-Energy Synchrotron X-Ray Microscopy

Four billion people suffer from lack of clean water at least one month of the year.[1] This critical water shortage applies not only to the supply of potable water, but also to water for use in industrial, agricultural, and energy applications. While water resources like seawater are abundant, hardly any water resource is clean enough for direct use. Desalination provides a methodology to render unusable waters from such water resources fit for use. An innovative and particularly energy-efficient electrochemistry-based approach is the Desalination Battery (DB), which stores the energy input during desalination in chemical bonds between ions and faradaic electrode, allowing for its recovery during the salination process. DBs are at the forefront of the water-energy nexus[2]. While they are promising for seawater desalination (e.g., for seawater to brackish water conversion), practical implementation and their full potential still need to be unlocked. To this end, foundational understanding of the atomic- to electrode-scale physics/chemistry underlying functionality and degradation must be unraveled.Towards this end, we utilized our unique flow-by reactor setup to combine electrochemistry, conductivity, and temperature measurements with high-energy (75 keV) operando synchrotron X-ray diffraction (HEXRD) microscopy. Our investigation encompasses both the atomic and electrode levels, using a 3-electrodes setup with LiMn2O4 and Na0.44MnO2 as electrode active materials. As such, we were able to simulate a realistic electrode environment for operando measurements, as well as observe spatially resolved structural changes by scanning the beam across the electrodes surface. These phenomena are manifested through changes in unit cell parameters and the emergence of new phases during desalination cycles. Specifically, we tracked the changes in XRD patterns over the course of several desalination cycles in LiCl and NaCl solutions, as well as synthetic seawater and mixed solutions of LiCl/MgCl2. We were able to observe high selectivity of LiMn2O4 towards Li+, even in the highly concentrated synthetic seawater solutions, and could not observe the emergence of a new Mg+ rich phase down to potentials of 0 V vs. AgCl. Na0.44MnO2 exhibited good cycling behavior in synthetic seawater akin to pure NaCl solutions, and apart from the Na+ rich phase showed no signs of additional new phases, suggesting a highly selective nature towards Na+. Furthermore, we compared constant current and constant potential protocols and observed distinct differences in peak shift behavior. Ongoing analysis of the unit cell parameters and atomic positions allows us to allocate specific intercalation sites to specific potentials, providing foundational insight into the chemistry and physics underlying the selectivity of these materials.Literature:[1] M. M. Mekonnen, et al., Sci Adv 2016, 2, e1500323.[2] Q. Li, et al., Adv Sci (Weinh) 2020, 7, 2002213.

Nanoporous Silica Lattice Coated with LiCl@PHEA for Continuous Water Harvesting from Atmospheric Humidity

AbstractRecently, atmospheric water harvesting (AWH) based on hygroscopic salt on an inorganic or organic carrier has attracted great attention because of its significant potential applications in the environment. The major technical challenges for practical applications are how to prevent the leakage of hygroscopic salt while achieving a high capacity for sorption of atmospheric water and a high sorption rate. Additionally, techniques for converting sorbed water (in the form of a lithium chloride (LiCl) solution) into clean water need to be developed. Here, a novel method for continuous atmospheric water harvesting, leveraging LiCl@PHEA hydrogels is introduced. Synthesized via one‐step UV polymerization in saturated LiCl solutions, these hydrogels exhibit remarkable air distension ability (&gt;60 times), achieving high water sorption efficiency (11.18 gg−1 at 90% relative humidity in 30 min) with over 90 wt.% salt content and no leakage. This water collection system integrates a porous evaporator and a 3D‐printed silica substrate, ensuring an extraordinarily high evaporation rate (&gt;11 kgm−2 h−1 under sunlight) and efficient water transmission. A prototype based on this achieves a record‐breaking collection rate of over 5 kgm−2 h−1, enabling large‐scale efficient atmospheric water harvesting. Additionally, continuous hydrogen production through electrolysis using the collected water (&lt; 5 ppm of salts) is demonstrated.

Performance activation mechanism of aluminum-based layered double hydroxides adsorbents for recovering Li+ by pH modulating

Aluminum-based adsorbents, simply prepared by eluting the lithium-aluminum layered double hydroxide precursors with deionized water, is the only industrialized adsorbents for selectively separating Li+ from saline brines. Taking the roles of lattice and surface Li+ active sites on its performances into consideration, influence of ending pH modulating on prominently improving the adsorbing capacity and stability of aluminum-based adsorbents prepared by precipitation method is initially investigated. As experimentally evidenced that, the maximum desorption amount of Li+ at the eluting stage should be controlled to around 20 mg/g Li+ rather than thoroughly removed to effectively avoid the topotactic solid-phase transformation from adsorbent to α-Al(OH)3. As-prepared adsorbents not only has high adsorption capacity up to 8.4 mg/g in 400 ppm LiCl solution, but also owns unique self-healing ability, thus promising the excellent cycling stability. It is firstly proposed that the formation of the layer-structured precursor by precipitation method is well in accordance with the three-step formation mechanism and pH modulating mainly contributes to the anions exchange between solution Cl- and interlayer OH–. This study experimentally proves the importance of pH adjusting for preparing high performance lithium adsorbents by precipitation method, which is very significant and important for effectively extracting lithium resources from the complicated multi-component liquid minerals.

Peculiarities of the potentiometric response of ISEs with membranes containing two neutral ionophores and an excess of ion-exchanger: Experiment and modeling

The potentiometric response of ion-selective electrodes (ISEs) with membranes simultaneously containing two ionophores: valinomycin and lithium ionophore Li VIII, as well as the cation exchanger potassium tetrakis(p-Cl-phenyl) borate in different concentrations is studied in KCl, LiCl and KCl + LiCl solutions. It is shown that ISEs with a membrane containing an excess of ionophores over the ion-exchanger provide Nernstian response to K+ and to Li+ ions. However, membranes with an excess of the ion-exchanger over valinomycin show Nernstian response to K+ only in mixed KCl + LiCl solutions with constant ratios of the concentrations of these electrolytes. On the contrary, the response to Li+ is obtained both in mixed and pure LiCl solutions. The results are semi-quantitatively explained using a simple mathematical model and respective computer simulation.

Preferential lithium extraction and simultaneous ternary cathode precursor synthesis from spent lithium-Ion batteries using a spray pyrolysis-based process

Spent LiNixCoyMnzO2 (NCM) recycling ensures the sustainable development of lithium-ion batteries (LIBs) industry by returning valuable metals back to the supply chain. However, traditional recovery techniques for extracting metals from spent NCM necessitate tedious separation and purification operations. Herein, a spray pyrolysis-based process has been proposed for spent NCM recycling, which achieves the preferential lithium (Li) extraction and ternary cathode precursor synthesis simultaneously. Specifically, after a process sequence ofchlorination roasting, spray pyrolysis, water leaching, spent NCM cathode powder is transformed into a LiCl solution and ternary oxide, which can be directly used for the synthesis of battery-grade Li2CO3 and NCM cathode, respectively. The pyrolysis behavior of different metal chloride solution is systematically examined and related thermodynamical mechanism is discussed. Besides, the residual Cl in the pyrolyzed powder is found to have a great influence on recovery efficiency and a corresponding Cl elimination method is proposed. Under the optimized conditions, >88 % of Li can be preferentially leached out and the regenerated single-crystal NCM811 retains 80 % capacity after 300 stable cycles at 1C. This work offers a short and robust process for obtaining high-value-added products from spent NCM cathode.