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A novel strategy is proposed by constructing TFSI - ion-sieve interlayer to guide Li-ion selective transport and solid SEI growth. The uniform MgF 2 seeds on the fiber surface reacts rapidly with Li + in electrolyte to form Mg and LiF dual functional sites for the first charging process. Benefiting from the high affinity of LiF, the TFSI - ions is enriched near the anode forming an ion-sieve interlayer, which acts as a protective umbrella and guides priority penetration of Li + due to the coordination reaction with Li + and thus homogenize the Li + flux. While the Mg sites induce Li nucleation with its strong lithiophilicity and facilitate uniform Li plating on fiber surface. Furthermore, as raw material of LiF, the TFSI - enrichment on anode surface is contribute to increasing LiF content in SEI, achieving the stability enhancement and densification of SEI. Of greater importance, the excess Li + can spread to the adjacent Mg sites for nucleation by means of ultralow Li + migration barrier on LiF and Mg. The combination of the ion-sieve homogenization of Li + flux in electrolyte and the uniformity of Li + transport in LiF/Mg solid medium achieves the purpose of uniform Li metal plating/stripping., (© 2024 Wiley‐VCH GmbH.)

Among the manganese-based lithium-ion sieves, Li 1.6 Mn 1.6 O 4 has a high theoretical lithium adsorption capacity as a spinel ion sieve material. Small particle size orthogonal phase purity LiMnO 2 powders were prepared by a semi-wet method and calcined in air at 400 °C to obtain Li 1.6 Mn 1.6 O 4 a lithium-ion sieve precursor. The synergistic effects of oxygen atmosphere, heat treatment conditions and lithium/manganese molar ratio on the crystal structure of LiMnO 2 and the lithium adsorption/desorption characteristics of Li 1.6 Mn 1.6 O 4 were comprehensively investigated with XRD, SEM, TEM, XPS, Raman, DTA-TG and capacity retention study. Notably, when the initial lithium/manganese molar ratio was set at 1.1, and the sample underwent a calcination at 120 °C for 48 h under carefully controlled deoxygenation conditions, we observed the exclusive presence of the desired orthorhombic phase in the LiMnO 2 sample. In contrast, when the synthesis conditions deviated from the optimized parameters led to the presence of the monoclinic phase of Li 2 MnO 3. This highlights the sensitivity of Li 1.6 Mn 1.6 O 4 properties to the synthesis conditions. The results of adsorption-desorption cycles show that the ion sieve Li 1.6 Mn 1.6 O 4 prepared by heat treatment of ordered o-LiMnO 2 is more stable, the structural stability of Li 1.6 Mn 1.6 O 4 were characterized by high-temperature in-situ XRD experiments during heating from 30 to 800 °C. The equilibrium adsorption capacity was 34 mg g−1 in Qarhan Salt Lake brine at 10th cycle, and a remarkably low Mn dissolution loss rate of 0.6 %. The results have significant potential to advance the development of high-performance adsorbent in the Li-Mn-O system and contribute to the advances in lithium separation technology. [Display omitted] • Under the optimized synthesis conditions and control of oxidation environment, the relatively pure phase o-LiMnO 2 was obtained. • Deox-HMO 4 showed highly anti-dissolution properties for the lithium adsorption from brine water. • Deox-HMO 4 has been proved to have excellent practical application prospects. • Deox-HMO4, after 10 cycles, exhibits a minimal manganese dissolution loss of only 0.61%. [ABSTRACT FROM AUTHOR]

With the large-scale use of lithium-ion batteries, the global demand for lithium resources has increased dramatically. It is essential to extract lithium resources from liquid lithium sources such as brine and seawater, as well as recycled waste lithium-ion batteries. Among various liquid lithium extraction technologies, lithium ion-sieve (LIS) adsorption is considered to be the most promising method for its low energy consumption and environment-friendly. This method has advantages of excellent lithium uptake capacity, high selective, and good regeneration performance. In this review, we summarized the development of lithium manganese oxides (LMO)-type LIS, including the chemical structure, lithium intercalation/de-intercalation mechanism, preparation methods and forming technology of this material. The problems in the industrial application of ion-sieves are put forward, and the future research directions are prospected. Image 1 • We summarized the basic information of LIS adsorbent, including the chemical structure and lithium intercalation/de-intercalation mechanism. • In this review, the preparation methods of LIS precursors are introduced. • The latest developments in LIS forming methods are reviewed, with an emphasis on granulation, membrane formation and foaming. [ABSTRACT FROM AUTHOR]

Manganese dioxide ion‐sieves are known to be highly efficient lithium adsorbents, owing to their high adsorption capacity and selectivity. However, their manganese dissolution rate during acid desorption is high. Therefore, electrically switched ion exchange (ESIX) was proposed to recover Li+ from brine. Cyclic voltammetry results indicated that ESIX could be applied to capture lithium from the Li+‐containing solutions. Besides, the electrochemical behaviour of Li+ in LiMn2O4/λ‐MnO2 structures was studied, wherein Na+, K+, Ca2+, and Mg2+ naturally coexisted with Li+ in the brine. No redox peaks were observed between 0.3–1.2 V in the MCl solution (MCl = NaCl, KCl, CaCl2, and MgCl2), and the positions of the redox peaks in the LiCl solution were similar to those in the LiCl and MCl mixed solution, indicating that Na+, K+, Ca2+, and Mg2+ barely interacted with the λ‐MnO2 electrode under the experimental conditions. Based on the experimental results, the Li+ adsorption capacity was determined to be ∼2 mmol · g−1, and the selectivity coefficients of Li+ for Na+, K+, Ca2+, and Mg2+ were 38.78, 35.63, 29.04, and 120.08, respectively. Furthermore, by using ESIX, the Li+ adsorption capacity of the λ‐MnO2 electrode was 82.8 % of its initial value after 50 adsorption‐desorption cycles. Thus, we concluded that ESIX involving an λ‐MnO2 electrode can be used to separate Li+ from brine with excellent selectivity coefficients. [ABSTRACT FROM AUTHOR]

The controllable and low-cost synthesis of nanometal particles is highly desired in scientific and industrial research. Herein, size-tunable Ru nanoparticles were synthesized by using a novel ion-sieve-confined reduction method. The H 2 TiO 3 ion-sieve was used to adsorb Ru 3+ into the hydroxyl-enriched porous [TiO 3 ] 2- layers. The confined environment of the interlayer space facilitates Ru-Ru collision and bonding during annealing, achieving a precise reduction from Ru 3+ to Ru 0 without additional reductants. Owing to the confinement effect, Ru 0 nanoparticles are uniformly embedded in the pores on the surface of the postannealed TiO 2 matrix (Ru@TiO 2 ). Ru@TiO 2 exhibited a lower overpotential than Pt/C (57 vs 87 mV at 10 mA cm -2 ) for the HER in 0.1 M KOH solution. The confinement-induced reduction of metal ions was also preliminarily proved in ion-exchanged zeolites, which provides facile and abundant approaches for the size-controllable synthesis of nanometal catalysts with high catalytic activity.

A novel adsorbent lithium ion-sieve membrane (LISM) toward Li was successfully prepared by the phase inversion technique using synthesized lithium ion-sieve ultrafine powder as the precursor, poly(vinylidene fluoride) (PVDF) as a binder, N, N-dimethylacetamide (DMAc) as the solvent. The key design for the synthesis of LISM is the formation of lithium ion-sieve dropping with PVDF powder to obtain a highly selective adsorbent. The prepared LISM have been characterized. The X-ray diffraction illustrated that the synthesized lithium ion-sieve were purity phase cubic spinel structure, the scanning electron microscopy shown that the LISM with a poriferous surface morphology and lithium ion-sieve equably dispersed on the surface of the membrane. The membrane flux (9.7 mL cm min) suggested that the LISM achieved high hydrophily and stability. The maximum adsorption capacity is 27.8 mg g in a high adsorption rate towards Li within 60 min. In addition, the LISM has excellent adsorption selectivity, since the separation factor α is 4.76 with respect to Mg. Overall results revealed that the LISM as a good candidate for Li separation and concentration from salt lake brine with a relatively high value of Mg/Li ratio. [ABSTRACT FROM AUTHOR]

The Mn-based Li 1.6 Mn 1.6 O 4 ion sieve is among the most effective lithium adsorbents due to its high lithium-ion adsorption capacity and selectivity for Li-ions. However, the inherent disadvantages of manganese dissolution and low structural stability prevent its industrial application. In this study, a series of Li 1.6 Mn 1.6 O 4 @R were synthesized by the low temperature solid phase hydrothermal method that exhibit highly anti-dissolution properties for the lithium adsorption from brine water. The LMO-L, LMO-LM, and LMO-M adsorbents show great adsorption capacities of 46.0 mg g−1, 43.0 mg g−1, and 38.0 mg g−1 compared to the 42.3 mg g−1 for the pristine adsorbent. After 20 cycles the dissolution loss of Mn was 0.06 % of LMO-L adsorbents. This improvement in adsorption properties is attributed to the stabilized layered structure due to the evolution of oxygen during the coating reaction, and the inhibition of the interfacial side reactions between the solution and the adsorbent by metal oxide coating. X-ray diffraction, and X-ray photoelectron spectroscopy analysis indicate the formation of Li 2 MnO 3 on the material surface, which can increase tetravalent manganese on the surface. Furthermore, our work may provide new insights for the design of efficient Mn-based adsorbents with high stability for water treatment applications. Metal oxide-Coated Li 1.6 Mn 1.6 O 4 @R were synthesized by the one-step low temperature solid phase hydrothermal method. [Display omitted] • Metal oxide-coated Li 1.6 Mn 1.6 O 4 @R were synthesized by the one-step low temperature solid phase hydrothermal method. • LMO@R showed highly anti-dissolution properties for the lithium adsorption from brine water. • LMO@R has been proved to have excellent practical application prospects. [ABSTRACT FROM AUTHOR]

This study presents the recovery of lithium from borogypsum by lithium ion-sieves known as selective adsorbents. In the study two types of ion-sieves were used. One was λ-MnO 2 which was obtained by the treatment of LiMn 2 O 4 with acid and the other was prepared via the acid treatment of LiNi 0 . 5 Mn 1 . 5 O 4 which occurred by the substitution some of manganese with nickel. Besides the lithium adsorption and desorption capacities, manganese and nickel dissolution ratios from the spinel powders were also studied. Optimum adsorption and desorption conditions were determined in the LiOH and HCl solutions. XRD and SEM analyses showed that substitution of manganese with nickel and treatment of spinel powders with acid did not destroy the spinel structure and morphology. Because of the cell-contraction, nickel-substituted spinel did not show any satisfying Li + extraction and adsorption properties. [ABSTRACT FROM AUTHOR]

The ion exchange adsorption method is the most promising technique for lithium recovery from low-grade brines, and the main adsorbents are titanium-based and manganese-based ion-sieves. Their expensive cost and poor cycling performance, which have limited their industrial applications, need to be solved fundamentally by finding a new ion-sieve. Hence, in this work, a high-stability and low-priced lithium ion-sieve with aluminosilicate framework was successfully synthesized by solid-phase sintering. The cheap silicon and aluminum raw materials make this ion-sieve have a low synthesis cost. The adsorption behavior of ion-sieves fits the Langmuir model and pseudo-second-order kinetics, indicating that the adsorption of lithium is mainly monolayer adsorption, and the process is chemisorption. After ten cycles, the lithium adsorption capacity is still over 27 mg/g. Moreover, it can recover lithium in the brine of West Taijinar Salt Lake in China even at 160 °C due to the excellent stability of the aluminosilicate framework, which can effectively improve its industrial production efficiency. Therefore, it has great potential to extract lithium from liquid lithium resources with a high Mg/Li ratio. • The ion-sieves with aluminosilicate framework can be easily synthesized by solid phase method. • Silicon and aluminum can effectively reduce the cost of the ion sieves. • The adsorbents exhibit excellent selectivity and stability. [ABSTRACT FROM AUTHOR]

Highlights: [•] PVC-Li1.6Mn1.6O4 precursor membranes were prepared by the solvent exchange method. [•] The lithium ion-sieve membrane has high selectivity for Li+ with coexisting ions. [•] It exhibits high stability after eight repeated adsorption–desorption cycles. [•] The thickness of membrane effects on adsorption capacity and mechanical strength. [Copyright &y& Elsevier]

Abstract: A new inorganic ion exchanger, zirconium molybdopyrophosphate, was synthesized by both precipitation and hydrothermal reactions. Through orthogonal experiments the sample obtaining the highest cesium exchange capacity was chosen and characterized by X-ray diffraction, scanning electron microscope, specific surface area along with determination of pH at the point of zero charge. Batch experiments were carried out to evaluate the effects of operational parameters such as initial pH, exchanger dose, contact time and Cs+ concentration on the cesium exchange capacity of the optimum sample. Evolution of solution pH presented in each case evidenced the main Cs+–H+ ion exchange mechanism. The pH at the point of zero charge indicated this ion exchanger as monofunctional and acidic in character. The ion exchange process followed the Langmuir and pseudo-second-order model. The results showed that the optimum sample with a considerable capacity of 1.21mmol/g might be a suitable precursor for cesium ion-sieve. [Copyright &y& Elsevier]

The cubic phase LiMnO precursors are prepared by high-temperature calcinations (1003 K) of LiOH⋅HO and MnO mixture with Li/Mn molar ratio = 0.55. The LiMnO precursors are synthesized via low-temperature solid-phase reaction (673 K) of LiNO and MnO mixture with Li/Mn molar ratio = 1.0. The ion-sieves counterparts (named SMO-H and SMO-L, respectively) are obtained by the acid treatment of Li-Mn-O precursors. The structure, chemical stability, morphology, ion-exchange property and mechanism of Li-Mn-O precursors and MnO ion-sieve were systematically examined via X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected-area electron diffraction (SAED), Infrared Spectroscopy (IR), X-ray photoelectron spectroscopy (XPS) and lithium ion selective adsorption measurements. The result shows the more compact Mn-O lattice makes the LiMnO spinel more stable after the Li is extracted. The results of IR and XPS show adsorption process of SMO-H exists ion-exchange between the Li and protons, and redox reaction, but only exists ion-exchange between the Li and protons in SMO-L. Agglomeration is well-improved by low calcination temperature and the morphology of the LiMnO precursor and final MnO ion-sieve are effectively controlled within low-dimensional structure. The maximum pH titration capacity of SMO-L for Li is 6.76 mmol⋅g, but only 3.47 mmol⋅g for SMO-H. The ion-sieve obtained from LiMnO precursor is promising in the lithium extraction from brine or seawater. [ABSTRACT FROM AUTHOR]

Abstract: β-MnO2, spinel-type Li4Mn5O12 and pure cubic phase MnO2 nanorod, with the size about 20–140nm in diameter and 0.8–4μm in length, were synthesized via a combination of hydrothermal synthesis and low temperature solid-phase reaction, more favorable to control the nanocrystalline structure with well-defined pore size distribution and high surface area than the traditional high temperature calcination process. Further, the MnO2 ion-sieves with lithium selective adsorption property were prepared by the acid treatment process to completely extract lithium from the spinel Li4Mn5O12 precursor with little change to the Mn–O lattice structure and the 1-D nanorod morphology. The effects of hydrothermal and solid-phase reaction process on the nanostructure, chemical stability and ion-exchange property of the ion-sieve material were examined with powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), N2 adsorption–desorption at 77K, and Li+ selective adsorption measurements. The lithium selective adsorption capacity was improved remarkably to 6.62mmolg−1 at equilibrium and about 5mmolg−1 at the initial lithium concentration of only 5.0mmoll−1, which is significant for lithium extraction from aqueous solutions with very low lithium content. [Copyright &y& Elsevier]

Spinel-type ternary LiMn2O4 oxide precursor was synthesized by direct hydrothermal synthesis of Mn(NO3)2, LiOH, and H2O2 at 383 K for 8 h, a better technique for controlling the nanocrystalline structure with well-defined pore size distribution and high surface area than the traditional solid state reaction method. The final low-dimensional MnO2 nanorod ion-sieve with a lithium ion selective adsorption property was further prepared by an acid treatment process to completely extract lithium ions from the Li–Mn–O lattice. The effects of hydrothermal reaction conditions on the nanostructure, chemical stability, and ion-exchange property of the LiMn2O4 precursor and MnO2 ion-sieve were systematically examined via powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected-area electron diffraction (SAED), and lithium ion selective adsorption measurements. The results show that this new kind of low-dimensional MnO2 nanorod can be used for lithium extraction from aqueous environments, including brine, seawater, and waste water. [ABSTRACT FROM AUTHOR]

Abstract: The Li+ uptake was studied by two lithium ion-sieves with different properties (surface, crystal configuration, and grain size). The reaction of Li+ uptake was investigated in batch experiments via the pH technique. Equilibrium studies were performed in solution pH 7, 10, 12 and the Langmuir equation was applied to the data. The results indicated that there was strong responsive behavior of Li+ uptake to pH in neutral or weak alkaline solutions, and Li+ uptake could not proceed completely for reason of pH descent with proton releasing from ion-sieves. Sieve-2 had faster Li+ uptake rate than Sieve-1 owing to the quicker intraparticle diffusion in the small grain. The Li+–H+ ion-exchange was accepted as the main mechanism of Li+ uptake by spinel-type manganese oxide with manganese valence nearly equals to +4. Furthermore, it suggested that Li+ uptake by ion-sieves would be necessary to study in buffer solution. [Copyright &y& Elsevier]

• Modified synthesis method for preparation of Li 4 Ti 5 O 12 nanotubes. • Obtaining the lithium-ion sieve with the considerable specific surface area. • Significant lithium adsorption capacity achieved compared to the other studies. • Thermodynamics and Kinetics analysis of Li adsorption was carried out. In this study, H 4 Ti 5 O 12 nanotubes have been prepared as Li+ adsorbent by acid treatment of Li 4 Ti 5 O 12 nanotubes. Li 4 Ti 5 O 12 nanotubes were synthesized via a hydrothermal method in which TiO 2 (B) nanNotubes were used as a precursor. The prepared Li-ion sieve showed a significant high ion-exchange capacity (160.6 mgg−1) for lithium ions due to its large specific surface area of 115.4 m2 g-1 compared to the other related studies. The kinetics and isotherm investigation revealed that the pseudo-second-order equation well described the adsorption kinetics, and the Langmuir model well fitted the isotherm data. Furthermore, the low value of adsorption energy obtained from the Dubinin-Radushkevitch (D-R) isotherm suggests that the adsorption process is dominated by physisorption. Statistical analysis of experimental data using elementary statistical techniques demonstrated an acceptable agreement between experimental data and the proposed mathematical model. Overall, results show H 4 Ti 5 O 12 nanotube's capability as an attractive medium for large scale lithium extraction from aqueous resources. [ABSTRACT FROM AUTHOR]

Lithium is one of the most important light metals, which is widely used as raw materials for large-capacity rechargeable batteries, light aircraft alloys and nuclear fusion fuel. Seawater, which contains 250 billion tons of lithium in total, has thus recently been noticed as a possible resource of lithium. While, since the average concentration of lithium in seawater is quite low (0.17 mg·L−1), enriching it to an adequate high density becomes the primary step for industrial applications. The adsorption method is the most prospective technology for increasing the concentration of lithium in liquid. Among the adsorbents for lithium, the ion-sieve is a kind of special absorbent which has high selectivity for Li+, especially the spinel manganese oxides (SMO), which among the series of ion-sieves, has become the most promising adsorption material for lithium. In this study, the SMO ion-sieve was prepared by a coprecipitation method. The preparation conditions were discussed and the sample characters were analyzed. Recovery of Li+ from seawater were studied in batch experiments using prepared ion-sieve, and the effect of solution pH and the uptake rates were also investigated in different Li+ solutions. [ABSTRACT FROM AUTHOR]

Al-doped lithium manganese oxides Li 1.6 Al x Mn 1.6- x O 4 were successfully prepared by sol–gel synthesis and solid state reactions. Protonated samples were obtained by further acid treatment. Experiments were performed to study the effects of physical properties including the Al3+ doping content x and calcination temperature for optimizing the synthesis of H 1.6 Al x Mn 1.6-x O 4 ion-sieve pursing nice performance such as enlarging the adsorption capacity and minimizing dissolution loss of manganese. The characteristics of a series of Al-doped ion-sieve were studied by XRD, SEM and EDS. The crystal structure was kept well after Al doping from XRD analysis. SEM and EDS showed that Al was uniformly distributed in the sample. The valence state of Mn in Al-doped ion-sieve precursor was analyzed by XPS. Adsorption/desorption experiments were carried out to evaluate the amounts of lithium extraction, lithium adsorption capacity and the manganese and aluminum dissolution loss of the ion-sieve. The results showed that the Al-doped H 1.6 Mn 1.6 O 4 ion-sieve exhibited higher absorption capacity (which approached 32.6 mg g−1 while the undoped one reached only 27.6 mg g−1). Furthermore, the dissolution loss of manganese and aluminum from the Al-doped ion-sieve were the most impressive among the ones. Importantly, the Al-doped ion-sieve still preserve a high adsorption capacity (26.8 mg g−1) and pretty low manganese dissolution loss (1.92%) after performing up to 4 cycles of adsorption/desorption experiments, indicating an enhanced stability of the Al-doped H 1.6 Mn 1.6 O 4 ion-sieve. [ABSTRACT FROM AUTHOR]

The widespread use of lithium-ion batteries has led to continuously increasing demands for lithium. In order to recover lithium from geothermal water, a novel composite lithium ion-sieve was synthesized and applied in this work. The stability of the material was successfully solved by granulating using acid-alkali resistant polyvinyl chloride as a binder, and its adsorption performances were also improved by using polyethylene glycol (PEG-6000) as a porogen to obtain a polyporous structure. When the developed material was applied for lithium separation from geothermal water, the adsorption capacity reached 12.84 mg/g at 328.15 K with an equilibrium time of about 12 h. The material can be well regenerated using 0.25 mol/L HCl to realize cycle use. The separation factors between Li + and other co-existing ions were within the range of 273.58-521.28, and the attenuation of adsorption capacity after five cycles was no more than 2%. The high selectivity and reusability properties of the polyporous ion-sieve make the material a potential candidate for the selective separation and recovery of a low concentration of lithium from geothermal water.

Ion-sieves are a class of green adsorbent for extraction Li+ from salt lakes. Here, we propose a facile synthesis of hexagonal spinel LiMn2O4 (LMO) precursor under mild condition which was first prepared via a modified one-pot reduction hydrothermal method using KMnO4 and ethanol. Subsequently, the stable spinel structured λ-MnO2 (HMO) were prepared by acidification of LMO. The as-prepared HMO shows a unique hexagonal shape and can be used for rapid adsorption-desorption process for Li+ adsorption. It was found that Li+ adsorption capacity of HMO was 24.7 mg·g−1 in Li+ solution and the HMO also has a stable structure with manganese dissolution loss ratio of 3.9% during desorption process. Moreover, the lithium selectivity ( α Mg Li ) reaches to 1.35 × 103 in brine and the distribution coefficients ( K d ) of Li+ is much greater than that of Mg2+. The results implied that HMO can be used in extract lithium from brine or seawater containing high ratio of magnesium and lithium. [ABSTRACT FROM AUTHOR]