Recent Advances in the Lithium Recovery from Water Resources: From Passive to Electrochemical Methods

Sustainable lithium extraction from produced water: Integrating membrane pretreatment and next-generation adsorbents

With the surging demand for lithium in energy storage and electric vehicles, lithium production has become increasingly crucial to modern society. While conventional Salt Lake brines remain a primary lithium source, produced water-a byproduct of oil and gas extraction-has emerged as a promising alternative due to its considerable extraction potential. In this review, we propose an efficient and sustainable process that leverages the strengths of membrane treatment and lithium adsorption. This process combines membrane treatment as an efficient pretreatment method for produced water with adsorption as a highly selective and effective approach for subsequent lithium extraction. The review first examines conventional membrane materials, such as polysulfone and ceramics, for pretreatment, alongside key classes of lithium adsorbents, including titanium-based, manganese-based, and aluminum-based materials. It then discusses advancements and modifications in these materials, emphasizing performance enhancements for lithium recovery. Emerging material optimization strategies, such as electrochemical coupling and the development of fibrous adsorbents, are also discussed, highlighting their potential to improve efficiency and scalability. A detailed process roadmap is presented, demonstrating the integration of membrane-based pretreatment with adsorbent-based lithium recovery and underscoring the strong industrial adaptability of this approach. By providing a comprehensive analysis of material performance and process optimization, this review offers valuable insights into scalable, efficient, and sustainable solutions for lithium extraction from produced water.

Environmentally relevant concentrations lithium exposure induces neurotoxicity in yellowstripe goby (Mugilogobius chulae): Responses of BDNF/AKT/FoxOs in regulating glutamate excitotoxicity and mitochondrial function

The wide application of lithium in green energy and clinical psychiatry results in ubiquitous occurrence of lithium in aquatic environments. However, researches on the toxicity of lithium are largely confined to acute and/or high-dose scenarios, with insufficient data on its impacts on non-target organisms at environmental levels. The present study investigated the neurotoxicological effects of environmentally relevant concentrations of lithium exposure on yellowstripe goby (Mugilogobius chulae) and the related molecular response mechanisms. The results showed that lithium exposure significantly inhibited the expression of the target protein GSK-3β in the brain of M. chulae, and induced a series of harmful events including oxidative stress, glutamate accumulation, and even behavioral alteration. The organism mitigated the excitotoxic effects of glutamate accumulation by down-regulating ionotropic glutamate receptors. At the same time, the organism met the energy supply and alleviated oxidative stress by altering mitochondrial function. Notably, the stress regulators FoxOs and sestrins both modulated synaptic sensitivities to enhance the neural signaling and altered the energy metabolism pattern to alleviate energy crisis, all of which were important for maintaining neuronal survival and organismal homeostasis. In conclusion, lithium exposure induced glutamate excitability and led to a series of toxic events. Meanwhile, FoxOs played an important role in neural signaling and homeostatic regulation of energy metabolism in brain. This study furthered the comprehension of the neurotoxic impacts of lithium on aquatic organisms, elucidated the associated molecular mechanisms, and underscored the environmental risks posed by increasing lithium contamination.

The Development and Analysis of a Preliminary Electrodialysis Process for the Purification of Complex Lithium Solutions for the Production of Li2CO3 and LiOH

Direct lithium extraction (DLE) is emerging as a promising alternative to brine extraction although it requires further processing to obtain high-quality products suitable for various applications. This study focused on developing a process to concentrate and purify complex LiCl solutions obtained through direct lithium extraction (DLE). Two different chemical compositions of complex LiCl solutions were used, dividing the study into three stages. In the first part, lithium was concentrated to 1% by mass by evaporation. In the second, electrodialysis was used to alkalinize the LiCl solution and remove magnesium and calcium impurities under different current densities. The best results obtained were magnesium and calcium removals of 99.8% and 98.0%, respectively, and lithium recoveries of 99% and 96%. In the third stage, the selectivity of two different commercial cationic membranes (Nafion 117 and Neosepta CMS) was evaluated to separate Li+, K+, and Na+ cations under different current densities and volumetric flow rates. The Neosepta CMS membrane demonstrated higher lithium recovery. This study evaluated the quality of the purified lithium-rich solution and its potential use both in the production of Li2CO3 as well as in the electrochemical production of LiOH.

Restraining Lattice Distortion of LiMn2O4 Facilitates Fluidic Electrochemical Lithium Extraction from Seawater

Reversible electrochemical extraction using cathode materials shows great potential for selective lithium extraction from low-concentration aqueous sources. However, ion selectivity and structural distortion challenges have limited its application to sources like seawater. Here, we synthesize Nb-modified LiMn2O4 using a simple wet chemistry coating method, introducing minimal structural defects in the LiMn2O4 materials and enhancing stability with a LiNbO3 coating to limit lattice expansion. Additionally, operando XRD reveals reduced lattice distortion during Li+ intercalation/deintercalation. Electrochemical tests show that the composite achieves high stability (over 100 cycles), fast Li+ electrosorption, and robust ion selectivity. Furthermore, utilizing a fluidic electrochemical approach, we extract lithium from simulated seawater (3.5 ppm of Li+), achieving an absorption capacity of 13.8 mg g-1 and an energy consumption of 9.96 Wh g-1.

Crown Ether-Grafted Graphene Oxide-Based Materials-Synthesis, Characterization and Study of Lithium Adsorption from Complex Brine

Direct lithium extraction from unconventional resources requires the development of effective adsorbents. Crown ether-containing materials have been reported as promising structures in terms of lithium selectivity, but data on adsorption in real, highly saline brines are scarce. Crown ether-grafted graphene oxides were synthesized using 2-hydroxymethyl-12-crown-4, hydroxy-dibenzo-14-crown-4 and epichlorohydrin as a source of anchoring groups. The obtained carbonaceous materials were used to prepare chitosan-polyvinyl alcohol composites. The prepared materials (and intermediate products) were characterized using FTIR, XRD, Raman spectroscopy and SEM-EDS methods. Adsorption tests were performed in a pure diluted LiCl solution ([Li] = 200 mg/kg) as well as in a real, highly saline oilfield brine ([Li] ≈ 220 mg/kg), and the distribution coefficients (Kd) were determined. The obtained results show that Kd in pure LiCl solution was in the range of 0.9-75.6, while in brine it was in the range of 0.2-2.3. The study indicates that the high affinity for lithium in pure LiCl solution is mostly associated with the non-selective interaction of lithium ions with the graphene oxide matrix (COOH groups). It was also shown that the application of dibenzo-14-crown-4 moiety to graphene oxide modification groups increases the affinity of the composite material for lithium ions compared to an analogous material containing 12-crown-4-ether groups.

Recycling Lithium-Ion Batteries-Technologies, Environmental, Human Health, and Economic Issues-Mini-Systematic Literature Review

Global concerns about pollution reduction, associated with the continuous technological development of electronic equipment raises challenge for the future regarding lithium-ion batteries exploitation, use, and recovery through recycling of critical metals. Several human and environmental issues are reported, including related diseases caused by lithium waste. Lithium in Li-ion batteries can be recovered through various methods to prevent environmental contamination, and Li can be reused as a recyclable resource. Classical technologies for recovering lithium from batteries are associated with various environmental issues, so lithium recovery remains challenging. However, the emergence of membrane processes has opened new research directions in lithium recovery, offering hope for more efficient and environmentally friendly solutions. These processes can be integrated into current industrial recycling flows, having a high recovery potential and paving the way for a more sustainable future. A second method, biolexivation, is eco-friendly, but this point illustrates significant drawbacks when used on an industrial scale. We discussed toxicity induced by metals associated with Li to iron-oxidizing bacteria, which needs further study since it causes low recycling efficiency. One major environmental problem is the low efficiency of the recovery of Li from the water cycle, which affects global-scale safety. Still, electromembranes can offer promising solutions in the future, but there is needed to update regulations to actual needs for both producing and recycling LIB.

Li-ion transport in two-dimensional nanofluidic membranes

The growing demand for lithium, driven by its critical role in lithium-ion batteries (LIBs) and other applications, has intensified the need for efficient extraction methods from aqua-based resources such as seawater. Among various approaches, 2D channel membranes have emerged as promising candidates due to their tunable ion selectivity and scalability. While significant progress has been made in achieving high Li+/Mg2+ selectivity, enhancing Li+ ion selectivity over Na+ ion, the dominant monovalent cation in seawater, remains a challenge due to their similar properties. This review provides a comprehensive analysis of the fundamental mechanisms underlying Li+ selectivity in 2D channel membranes, focusing on the dehydration and diffusion processes that dictate ion transport. Inspired by the principles of biological ion channels, we identify key factors-channel size, surface charge, and binding sites-that influence energy barriers and shape the interplay between dehydration and diffusion. We highlight recent progress in leveraging these factors to enhance Li+/Na+ selectivity and address the challenges posed by counteracting effects in ion transport. While substantial advancements have been made, the lack of comprehensive principles guiding the interplay of these variables across permeation steps represents a key obstacle to optimizing Li+/Na+ selectivity. Nonetheless, with their inherent chemical stability and fabrication scalability, 2D channel membranes offer significant potential for lithium extraction if these challenges can be addressed. This review provides insights into the current state of 2D channel membrane technologies and outlines future directions for achieving enhanced Li+ ion selectivity, particularly in seawater applications.

Recent Advances in High-Rate Solar-Driven Interfacial Evaporation

Recent advances in solar-driven interfacial evaporation (SDIE) have led to high evaporation rates that open promising avenues for practical utilization in freshwater production and industrial application for pollutant and nutrient concentration, and resource recovery. Breakthroughs in overcoming the theoretical limitation of 2D interfacial evaporation have allowed for developing systems with high evaporation rates. This study presents a comprehensive review of various evaporator designs that have achieved pure evaporation rates beyond 4 kg m-2 h-1, including structural and material designs allowing for rapid evaporation, passive 3D designs, and systems coupled with alternative energy sources of wind and joule heating. The operational mechanisms for each design are outlined together with discussion on the current benefits and areas for improvement. The overarching challenges encountered by SDIE concerning the feasibility of direct integration into contemporary practical settings are assessed, and issues relating to sustaining elevated evaporation rates under diverse environmental conditions are addressed.

Recycling primary lithium batteries using a coordination chemistry approach: recovery of lithium and manganese residues in the form of industrially important materials

In this study, we have investigated the potential use of post-consumer primary lithium metal batteries (LMBs) commonly used in portable electronic devices to recover lithium and manganese in the form of industrially important materials. A direct reaction of lithium-containing electronic waste with a naturally sourced ester, methyl salicylate, combined with a wide range of aliphatic alcohols has been used as a general method for recovering lithium in the form of lithium aryloxides of different nuclearities [Li(OAr)(HOMe)2] (1), [Li(OAr)(HOAr)] (2), [Li(OAr)(HOEt)]2 (3), [Li(OAr)(H2O)]2 (4), [Li4(OAr)4(EGME)2] (5), [Li6(OAr)6] (6-8) for ArOH = methyl salicylate (1, 2, 4, 6), ethyl salicylate (3, 7), 2-methoxyethyl salicylate (5, 8), and EGME = 2-methoxyethanol. The hydrolysis of 7 was then used to synthesize lithium salicylate [Li(Sal)(H2O)]n (10), which is an important antioxidant in the production of oils and grease. The discharged cathode material of Li-MnO2 batteries was investigated as a source from which LiClO4, Li2CO3, LiMn2O4, and Mn2O3 can be recovered by means of water-alcohol extraction or calcination. Particular emphasis was placed on the detailed characterization of all battery components and their decomposition products. LMBs were completely recycled for the first time, and materials were recovered from the cathode and the anode.

Reduced Lattice Constant in Al-Doped LiMn2O4 Nanoparticles for Boosted Electrochemical Lithium Extraction

Extracting lithium selectively and efficiently from brine sources is crucial for addressing energy and environmental challenges. The electrochemical system employing LiMn2O4 (LMO) electrodes has been recognized as an effective method for lithium recovery. However, the lithium selectivity and stability of LMO need further enhancement for its practical applications. Herein, the Al-doped LMO with reduced lattice constant is successfully fabricated through a facile one-step solid-state sintering method, leading to enhanced lithium selectivity. The reduced lattice constant in Al-doped LMO is proved through spectroscopic analyses and theoretic calculations. Compared to the original LMO, the Al-doped LMO (LiAl0.05Mn1.95O4, LMO-Al0.05) exhibits highercapacitance, lower resistance, and improved stability. Moreover, the LMO-Al0.05 with reduced lattice constant can offer higher Li+ diffusion coefficient and lower intercalation energy revealed by cyclic voltammetry and multiscale simulations. When employed in hybrid capacitive deionization (CDI), the LMO-Al0.05 obtains a Li+ intercalation capacity of 21.7 mg g-1 and low energy consumption of 2.6 Wh mol-1 Li+. Importantly, the LMO-Al0.05 achieves a high Li+ extraction percentage (≈86%) with Li+/Na+ and Li+/Mg2+ selectivity of 1653.8 and 434.9, respectively, in synthetic brine. The results demonstrate that the Al-doped LMO with reduced lattice constant could be a sustainable solution for electrochemical lithium extraction.

Nitrogen-doped substrate material ion imprinting-capacitive deionization selective recovery of lithium ions from acidic solutions

With the continuous development of global industry and the increasing demand for lithium resources, recycling valuable lithium from industrial solid waste is necessary for sustainable development and environmental friendliness. Herein, we employed ion imprinting and capacitive deionization to prepare a new electrode material for lithium-ion selective recovery. The material morphology and structure were characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, and other characterization methods, and the adsorption mechanism and water clusters were correlated using the density functional theory. The electrode material exhibited a maximum adsorption capacity of 36.94 mg/g at a Li+ concentration of 600 mg/L. The selective separation factors for Na+, K+, Mg2+, and Al3+ in complex solution environments were 2.07, 9.82, 1.80, and 8.45, respectively. After undergoing five regeneration cycles, the material retained 91.81% of the initial Li+ adsorption capacity. Meanwhile, the electrochemical adsorption capacity for Li+ was more than twice the corresponding conventional physical adsorption capacity because electrochemical adsorption provides the energy needed for deprotonation, enabling exposure of the cavities of the crown ether molecules to enrich the active sites. The proposed environment-friendly separation approach offers excellent selectivity for Li+ recovery and addresses the growing demand for Li+ resources.

Understanding the Electrochemical Extraction of Lithium from Ultradilute Solutions

The electrochemical extraction of lithium (Li) from aqueous sources using electrochemical means is a promising direct Li extraction technology. However, to this date, most electrochemical Li extraction studies are confined to Li-rich brine, neglecting the practical and existing Li-lean resources, with their overall extraction behaviors currently not fully understood. More still, the effect of elevated sodium (Na) concentrations typically found in most Li-lean water sources on Li extraction is unclear. Hence, in this work, we first understand the electrochemical Li extraction behaviors from ultradilute solutions using spinel lithium manganese oxide as the model electrode. We discovered that Li extraction depends highly on the Li concentration and cell operation current density. Then, we switched our focus on low Li to Na ratio solutions, revealing that Na can dominate the electrostatic screening layer, reducing Li ion concentration. Based on these understandings, we rationally employed pulsed electrochemical operation to restructure the electrode surface and distribute the surface-adsorbed species, which efficiently achieves a high Li selectivity even in extremely low initial Li/Na concentrations of up to 1:20,000.

Material Design Strategies for Recovery of Critical Resources from Water

Population growth, urbanization, and decarbonization efforts are collectively straining the supply of limited resources that are necessary to produce batteries, electronics, chemicals, fertilizers, and other important products. Securing the supply chains of these critical resources via the development of separation technologies for their recovery represents a major global challenge to ensure stability and security. Surface water, groundwater, and wastewater are emerging as potential new sources to bolster these supply chains. Recently, a variety of material-based technologies have been developed and employed for separations and resource recovery in water. Judicious selection and design of these materials to tune their properties for targeting specific solutes is central to realizing the potential of water as a source for critical resources. Here, the materials that are developed for membranes, sorbents, catalysts, electrodes, and interfacial solar steam generators that demonstrate promise for applications in critical resource recovery are reviewed. In addition, a critical perspective is offered on the grand challenges and key research directions that need to be addressed to improve their practical viability.

Perspective on the use of methanogens in lithium recovery from brines

Methanogenic archaea stand out as multipurpose biocatalysts for different applications in wide-ranging industrial sectors due to their crucial role in the methane (CH4) cycle and ubiquity in natural environments. The increasing demand for raw materials required by the manufacturing sector (i.e., metals-, concrete-, chemicals-, plastic- and lubricants-based industries) represents a milestone for the global economy and one of the main sources of CO2 emissions. Recovery of critical raw materials (CRMs) from byproducts generated along their supply chain, rather than massive mining operations for mineral extraction and metal smelting, represents a sustainable choice. Demand for lithium (Li), included among CRMs in 2023, grew by 17.1% in the last decades, mostly due to its application in rechargeable lithium-ion batteries. In addition to mineral deposits, the natural resources of Li comprise water, ranging from low Li concentrations (seawater and freshwater) to higher ones (salt lakes and artificial brines). Brines from water desalination can be high in Li content which can be recovered. However, biological brine treatment is not a popular methodology. The methanogenic community has already demonstrated its ability to recover several CRMs which are not essential to their metabolism. Here, we attempt to interconnect the well-established biomethanation process with Li recovery from brines, by analyzing the methanogenic species which may be suitable to grow in brine-like environments and the corresponding mechanism of recovery. Moreover, key factors which should be considered to establish the techno-economic feasibility of this process are here discussed.

Novel LiAlO2 Material for Scalable and Facile Lithium Recovery Using Electrochemical Ion Pumping

In this study, α-LiAlO₂ was investigated for the first time as a Li-capturing positive electrode material to recover Li from aqueous Li resources. The material was synthesized using hydrothermal synthesis and air annealing, which is a low-cost and low-energy fabrication process. The physical characterization showed that the material formed an α-LiAlO₂ phase, and electrochemical activation revealed the presence of AlO₂* as a Li deficient form that can intercalate Li⁺. The AlO₂*/activated carbon electrode pair showed selective capture of Li⁺ ions when the concentrations were between 100 mM and 25 mM. In mono salt solution comprising 25 mM LiCl, the adsorption capacity was 8.25 mg g^-1, and the energy consumption was 27.98 Wh mol Li^-1. The system can also handle complex solutions such as first-pass seawater reverse osmosis brine, which has a slightly higher concentration of Li than seawater at 0.34 ppm.