Lithium Recycling Research Articles

Molecular dynamics study on the dissolution characteristics and cluster formation of Li2CO3 in supercritical water

Recycling lithium from electronic waste is the focus of current research on waste treatment and resource utilization, and environmentally friendly supercritical water technology is an important recycling method. It is necessary to study the dissolution and precipitation characteristics of lithium salt in supercritical water. In this paper, molecular dynamics (MD) and quantum mechanics (QM) were used to study the dissolution properties of Li2CO3 in supercritical water and the structure and properties of clusters. The potential mean force (PMF), radial distribution function (RDF), and coordination number (CN) showed that the solubility of Li2CO3 in supercritical water was more affected by temperature, and the trend was opposite to that of temperature, and the ion pairs in solution were mostly in CIP state. Cluster searches were performed for the cluster configurations and their distribution probabilities of CIP states in supercritical water. The electrostatic potential distribution and intermolecular interactions of the initial cluster configuration in the supercritical solution of Li2CO3 are calculated by the QM method. In this study, the cluster configuration with a planar symmetry structure accounted for the largest proportion, and the lowest free energy was −431.86308400 a.u.

A Green Closed-Loop Process for Selective Recycling of Lithium from Spent Lithium-Ion Batteries

We developed a highly selective recycling process to recover lithium from spent lithium-ion batteries with the easily degradable formic acid. The lithium can be completely extracted with a leaching efficiency of 100%. Other elements are rarely leached out with lithium with a leaching efficiency of lower than 5%, indicating a highly selective extraction only for lithium. The purity of recovered lithium carbonate is as high as 99.994% with an impressive recycling rate of 99.8%. In addition, the formic acid is reusable, which means that our proposed process does not produce any secondary waste.

Regenerated Ni-Rich Cathode Materials from Spent Li-Ion Batteries by a Closed Loop Process

The demand for rechargeable lithium-ion batteries (LIBs) has increased exponentially since they were first commercialized by Sony in 1991.[1] Due to the high energy density and excellent cycle stability, LIBs have been widespread utilized in electric vehicles and other applications. However, the lifespan of LIBs is limited. Thus, tons of spent LIBs are generated during the recent decades. More importantly, the price of raw materials, including lithium and cobalt salts, for producing LIBs grows significantly.[2, 3] Therefore, recycling these End-of-Life LIBs becomes a non-negligible part in the whole manufacturing process and hydrometallurgical process is the most common recycling method. Here, our group has demonstrated a closed loop recycling process, combining inorganic acid etching and coprecipitation reaction, to produce regenerated Ni-rich cathode materials. The regenerated LiNi0.83Mn0.06Co0.11O2 shows excellent performance: the first cycle discharge capacity is 214.1mAh/g at 0.05C in the voltage range of 2.8 - 4.3V and the initial columbic efficiency is 90.9%. The performance of our regenerated cathode materials is comparable to commercial cathode materials. In order to further optimize the properties of the regenerated LiNi0.83Mn0.06Co0.11O2, different elements, like Al, with various doping or coating methods will be utilized. Manthiram A. A reflection on lithium-ion battery cathode chemistry. Nature Communications 2020; 11(1):1550.Li W, Lee S, Manthiram A. High‐Nickel NMA: A Cobalt‐Free Alternative to NMC and NCA Cathodes for Lithium‐Ion Batteries. Advanced materials (Weinheim) 2020; 32(33):2002718-n/a.Hou J, Ma X, Fu J, Vanaphuti P, Yao Z, Liu Y, et al. A green closed-loop process for selective recycling of lithium from spent lithium-ion batteries. Green Chemistry 2022; 24(18):7049-7060.

Recycling of lithium and fluoride from LiF wastewater from LiF synthesis industry by solvent extraction

The LiF synthesis industry produces a large amount of wastewater that contains ∼0.36 g/L lithium and ∼1.10 g/L fluorine. The traditional treatment solidified fluoride by excessive CaO, resulting in waste of lithium resources and generation of CaF2-CaO solid waste. To recover the Li and F from the LiF wastewater, a two-section solvent extraction process using acidic solvent and mixed solvent as organic solvent was designed and the extraction mechanism were systematically investigated. The result showed that Li extraction was extracted by a cation exchange mechanism with D2EHPA (di-2-ethyl hexyl phosphoric acid), 99.72% Li recovery and battery-grade LiCl solution (3.40 g/L) were achieved by mixed the LiF aqueous with the saponified D2EHPA at 25 ℃ for 6 mins with 4.60 equilibrium pH. After then, F was recovered by mixed neutral solvent system, which coordination binding with HF molecule. The ultimately residue contains ∼1 mg/L Li and < 6 mg/L F. Besides, high-purity LiF products (LiF>99.95%) was generated by stripping with LiOH, F recovery is 99.45%. 2-stage extraction process realizes lithium and fluoride recovery with short process, no pollution and great prospect of industrialization.

Hydrometallurgical recycling of lithium from waste saggar: Studies on influential role of acid/alkaline additives, leaching kinetics and mechanism

Waste recycling has become crucial with the increasing attention paid to environmental rules and the fast-depleting resources of critical elements. Soaring demands for lithium in cathode materials of rechargeable batteries result in a surge in waste saggar after being used in the calcination of cathode precursor. The recycling of lithium from waste saggar is therefore imperative due to the high supply-risk of lithium. Herein, waste saggar composed of various mineral phases (26.26 % LiAlSi4O10 ≅ 0.6 % Li; 6.34 % Li4SiO4 ≅ 1.47 % Li; 0.79 % LiOH∙H2O ≅ 0.13 % Li; 0.03 % Li2CO3 ≅ 0.01 % Li) was leached in water for lithium extraction; while the effects of NaOH, Ca(OH)2, and H2SO4 as potential additives were examined under a wide temperature range of 5–80 °C. Interestingly, the observed order of leaching efficiency at lower temperature (20 °C) H2SO4 > NaOH > Ca(OH)2 was in variance with that at 80 °C (NaOH > H2SO4 Ca(OH)2). The apparent activation energy for lithium extraction was determined to be 29.8 kJ/mol using NaOH, 33.8 kJ/mol using Ca(OH)2, and 14.1 kJ/mol using H2SO4, indicating that the overall leaching process follows a mixed-controlled mechanism. The maximum efficiency of 94 % Li-extraction was achieved with NaOH which was used for the precipitation recovery of Li2CO3 of purity above 99 %.

Thermodynamics of Li+-Crown Ether Interactions in Aqueous Solvent.

Lithium ion-based batteries are ubiquitous in modern technology due to applications in personal electronics and high-capacity storage for electric vehicles. Concerns about lithium supply and battery waste have prompted interest in lithium recycling methods. The crown ether 12-crown-4 has been studied for its abilities to form stable complexes with lithium ions (Li+). In this paper, molecular dynamics simulations are applied to examine the binding properties of a 12-crown-4-Li+ system in aqueous solution. It was found that 12-crown-4 did not form stable complexes with Li+ in aqueous solution due to the binding geometry which was prone to interference by surrounding water molecules. In addition, the binding properties of sodium ions (Na+) to 12-crown-4 are examined for comparison. Subsequently, calculations were performed with the crown ethers 15-crown-5 and 18-crown-6 to study their complexation with Li+ as well as Na+. It was determined that binding was unfavorable for both types of ions for all three crown ethers tested, though 15-crown-5 and 18-crown-6 showed a marginally greater affinity for Li+ than 12-crown-4. Metastable minima present in the potential of mean force for Na+ render binding marginally more likely there. We discuss these results in the context of membrane-based applications of crown ethers for Li+ separations.

Enhanced lithium-ion adsorption by recyclable lithium manganese oxide-sepiolite composite microsphere from aqueous media: Fabrication, structure, and adsorption characteristics

A novel spherical structure, hydrogen-substituted lithium manganese oxide (LMO)-sepiolite (HMO-SEP) composite assembled from nanorods was fabricated via hydrothermal method combined with solid-phase method. The structure and composition of the as-prepared HMO-SEP was analyzed by a series of characterization techniques, and its adsorption behavior and characteristics for Li+ adsorption from aqueous media and recyclability were investigated in detail. The as-prepared HMO-SEP showed a typical IV-type gas adsorption isotherm with H3-type hysteresis loop at high P/P0, with a specific surface area of 46.49 m2/g and a pore size of 18.31 nm. The isotherm adsorption data of Li+ adsorption by HMO-SEP conform well to the Langmuir model, and the maximum adsorption capacity of Li+ reached 52.41 mg/g at 298 K. Kinetic studies showed that the adsorption process complies well with the pseudo-second-order model, reaching adsorption equilibrium within 8 h. The adsorption of Li+ by the resulting HMO-SEP is a spontaneous endothermic process with increasing entropy, with an adsorption ΔH of 21.9432 kJ/mol and an adsorption activation energy of 19.8092 kJ/mol. A suitable amount of SEP could improve the microstructure of the HMO-SEP through the interface effect between SEP and LMO. Such effect could enlarge the specific surface area and pore volume and improve the ion transport channels, thus enhancing the adsorption capacity towards Li+, stability, and recycling performance. The resulting HMO-SEP possesses excellent selective adsorption performance for Li+, even under high concentrations of Na+, K+, Ca2+, and Mg2+, stability, and regeneration–recycling performance. It has excellent potential for efficient use in the extraction of Li+ from aqueous media.

Selective recycling of lithium from spent lithium-ion batteries by carbothermal reduction combined with multistage leaching

The indiscriminate hydrometallurgical leaching of metallic ions from spent lithium-ion batteries derived black mass significantly hinders the targeted recovery of specific metal salts. Selective recycling of lithium from electrode materials has attracted much attention because of its high value and realizability. While carbothermal reduction combined with single stage water-leaching is an alternative pathway, impurities in the electrode materials will affect the reduction process and decrease the recycling efficiency. In this study, we proposed the concept of carbothermal reduction in combination with multi-stage leaching as a facile and earth friendly approach to recycle lithium from electrode materials. Results demonstrate that cathode material of LiNixCoyMn(1-x-y)O2 can be fully reduced to Li2CO3, LiAlO2, CoO, NiO, Co, Ni. Li2CO3 can be recycled by water-leaching while LiAlO2 can be recycled by alkali-leaching. Roasting process can make lithium ions out of the aluminum-containing precipitates to form water-soluble salts, and this part of lithium can be recycled by water-leaching again. Afterwards, the comprehensive recovery rate of lithium is 87.15% when the content of aluminum in electrode materials is up to 4.03%. Findings made from this study may inspire the next generation of greener hydrometallurgical pathways to recover lithium from electrode materials even with a high aluminum content.

A Review of Chemically Induced Intercalation and Deintercalation in Battery Materials

Intercalation is the fundamental process underlying lithium‐ion batteries and related technologies. While intercalation is electrochemically induced in batteries, it can also be performed with chemical redox agents. In principle, the two processes are equivalent, although there can be differences, such as rate control, side reactions, and charge transfer mechanisms. Chemically induced intercalation can be used where electrochemical methods are impractical or impossible and continues to inspire innovative applications. This chemistry is important in synthesis and pretreatment of intercalation materials, with novel impactful applications emerging that range from lithium recycling to intercalation material‐based redox flow batteries. This review summarizes the use of chemical intercalation and serves as a resource for selecting and optimizing methods specific to material and application. Covering the whole life cycle of intercalation materials: development, synthesis, use, and finally recycling, it can be expected that these reactions will continue to have great impact on the path toward efficient and cheap energy storage.

Kinetic enhanced separation of praseodymium and neodymium induced by specific ion effect

The precise and controllable separation of Pr/Nd is the key to restricting the recovery of rare earths from neodymium magnets. However, it is difficult to realize the efficient separation by difference in thermodynamic properties of Pr3+ and Nd3+. In present work, the enhanced separation was achieved by a kinetic extraction strategy in systems with different salting-out agents. The comprehensive effect of multiple ions including salt anions and cations on enhanced separation of Pr3+/Nd3+ were investigated. Experimental results revealed that the separation coefficient can be higher than 8. The enhancing effect on separation of Pr3+/Nd3+ from different salting-out agents followed the order of NaCl < NaNO3 < NaSCN < LiNO3. It had a relationship with the salting-out effect, which could be influenced by the type and concentration of salting-out agents. In details, the salting-out effect was closely related with hydration of salt anions and cations. There are differences in the binding ability of rare earth ions to the above anions. The behaviors of rare earth ions arriving at the interface were different under specific ion effect of Li+ and Na+. By molecular dynamics simulations, it verified that the separation behaviors were related with diffusion mass transfer rate to the interface and the adsorption behaviors of rare earth ions at the interface. At the end, the recycling and recovery of lithium was suggested. This work provides a basis for developing a new method for efficient and green separation of adjacent rare earths.

Polyether-tethered imidazole-2-thiones, imidazole-2-selenones and imidazolium salts as collectors for the flotation of lithium aluminate and spodumene.

Imidazolium salts were prepared which possess 2-ethoxyethyl pivalate or 2-(2-ethoxyethoxy)ethyl pivalate groups as amphiphilic side chains with oxygen donors as well as n-butyl substituents as hydrophobic groups. The N-heterocyclic carbenes of the salts, characterized by 7Li and 13C NMR spectroscopy as well as by Rh and Ir complex formation, were used as starting materials for the preparation of the corresponding imidazole-2-thiones and imidazole-2-selenones. Flotation experiments in Hallimond tubes under variation of the air flow, pH, concentration and flotation time were performed. The title compounds proved to be suitable collectors for the flotation of lithium aluminate and spodumene for lithium recovery. Recovery rates up to 88.9% were obtained when the imidazole-2-thione was used as collector.

Exploring the potential for improving material utilization efficiency to secure lithium supply for China's battery supply chain

Lithium-ion battery (LIB) is the key technology for climate change mitigation. The sustainability of LIB supply chain has caused widespread concern since the material utilization efficiency of LIB supply chain has not been well investigated. This study aims to fill this research gap by conducting a dynamic material flow analysis of lithium in China from 2015 to 2021. Results indicate that within the temporal boundary, lithium flow and in-use stock grew significantly in China due to the rapid development of the EV market, with lithium flow in domestic production of basic chemicals increasing by 614% to 100 kt, end-use consumption increasing by 160% to 35 kt, and in-use stock increasing by 62% to 195 kt. China has been a net importer of lithium, of which cumulative imports and exports were 343 kt and 169 kt, respectively. In addition, 103 kt of lithium was converted to inventories or was lost during the processing from 2015 to 2021. By optimizing inventory and processing, developing substitutes for lithium for non-battery applications, and improving lithium recycling, China's net import dependency of lithium could be reduced from 27%-86% to 0%-16%. Our study demonstrates that it is urgent to improve material utilization efficiency so that the lithium resource supply can be secured.

Poly(ionic liquid) membranes preserving liquid crystalline microstructures for lithium-ion enrichment

The combination of membrane separation technology and hydrometallurgy has opened up new possibilities for the recovery and recycling of lithium from ever-growing spent lithium-ion batteries. Herein, we prepared a series of positively charged poly(ionic liquid) membranes preserving liquid crystal mesophases and investigated the monatomic ion separation capacity of the liquid crystalline membranes by diffusion dialysis experiments using the simulative spent battery leachate. The results revealed that liquid crystalline membranes with bicontinuous cubic liquid crystal structure possessed great potential as precise ion separation membranes for lithium-ion enrichment. Compared to the other topological structures, the bicontinuous cubic liquid crystal structure enhanced both the Li+ flux and ion selectivity of the membranes. The ion flux of the membrane with this structure was three times higher than that of amorphous membranes. Meanwhile, the Li+/Ni2+ selectivity was up to 7.40, which was significantly higher than that of hexagonal liquid crystalline membranes (2.59) and commercial membranes AMI-7001S (5.71). Moreover, the preservation of liquid crystal structures obviously improved the water management capacity and mechanical strength of the membranes.

A Paradox over Electric Vehicles, Mining of Lithium for Car Batteries

Lithium, a silver-white alkali metal, with significantly high energy density, has been exploited for making rechargeable lithium-ion batteries (LiBs). They have become one of the main energy storage solutions in modern electric cars (EVs). Cobalt, nickel, and manganese are three other key components of LiBs that power electric vehicles (EVs). Neodymium and dysprosium, two rare earth metals, are used in the permanent magnet-based motors of EVs. The operation of EVs also requires a high amount of electricity for recharging their LiBs. Thus, the CO2 emission is reduced during the operation of an EV if the recharged electricity is generated from non-carbon sources such as hydroelectricity, solar energy, and nuclear energy. LiBs in EVs have been pushed to the limit because of their limited storage capacity and charge/discharge cycles. Batteries account for a substantial portion of the size and weight of an EV and occupy the entire chassis. Thus, future LiBs must be smaller and more powerful with extended driving ranges and short charging times. The extended range and longevity of LiBs are feasible with advances in solid-state electrolytes and robust electrode materials. Attention must also be focused on the high-cost, energy, and time-demand steps of LiB manufacturing to reduce cost and turnover time. Solid strategies are required to promote the deployment of spent LiBs for power storage, solar energy, power grids, and other stationary usages. Recycling spent LiBs will alleviate the demand for virgin lithium and 2.6 × 1011 tons of lithium in seawater is a definite asset. Nonetheless, it remains unknown whether advances in battery production technology and recycling will substantially reduce the demand for lithium and other metals beyond 2050. Technical challenges in LiB manufacturing and lithium recycling must be overcome to sustain the deployment of EVs for reducing CO2 emissions. However, potential environmental problems associated with the production and operation of EVs deserve further studies while promoting their global deployment. Moreover, the combined repurposing and remanufacturing of spent LiBs also increases the environmental benefits of EVs. EVs will be equipped with more powerful computers and reliable software to monitor and optimize the operation of LiBs.

A green and sustainable strategy toward lithium resources recycling from spent batteries.

Recycling lithium from spent batteries is challenging because of problems with poor purity and contamination. Here, we propose a green and sustainable lithium recovery strategy for spent batteries containing LiFePO4, LiCoO2, and LiNi0.5Co0.2Mn0.3O2 electrodes. Our proposed configuration of “lithium-rich electrode || LLZTO@LiTFSI+P3HT || LiOH” system achieves double-side and roll-to-roll recycling of lithium-containing electrode without destroying its integrity. The LiTFSI+P3HT-modified LLZTO membrane also solves the H+/Li+ exchange problem and realizes a waterproof protection of bare LLZTO in the aqueous working environment. On the basis of these advantages, our system shows high Li selectivity (97%) and excellent Faradaic efficiency (≥97%), achieving high-purity (99%) LiOH along with the production of H2. The Li extraction processes for spent LiFePO4, LiNi0.5Co0.2Mn0.3O2, and LiCoO2 batteries is shown to be economically feasible. Therefore, this study provides a previously unexplored technology with low energy consumption as well as high economic and environmental benefits to realize sustainable lithium recycling from spent batteries.

Recycling of lithium, cobalt, nickel, and manganese from end-of-life lithium-ion battery of an electric vehicle using supercritical carbon dioxide

The widespread utilization of lithium-ion batteries (LIBs) will lead to multimillion tons of end-of-life LIBs. The batteries comprise high content of valuable metals including lithium, cobalt, nickel, and manganese; hence, their recycling is imperative. This study develops a supercritical fluid extraction process using supercritical CO 2 solvent with tributyl phosphate–nitric acid and hydrogen peroxide adduct to recover the four metals from the LIBs of electric vehicles. A full factorial design of experiment is utilized to determine the effect of temperature, pressure and adduct to solid ratio on the extraction. The extraction is optimized using empirical models, leading to 90% metal extraction. The addition of hydrogen peroxide improves the extraction by reducing metals to more soluble forms in supercritical CO 2 . A systematic investigation is performed to elucidate the process mechanism. The developed process can help management of end-of-life LIBs, conserve of natural resources, and promote the circular economy . Graphical Abstract. .

Improving the lithium recovery using leached beta-spodumene residues processed by magnetic nanohydrometallurgy

World's largest production of lithium is mostly performed through the acid lixiviation of β-spodumene mineral (LiβS), LiAlSi2O6. The process generates large amounts of leached spodumene residues (LSR) containing the protonated form, here denoted HβS, among the several impurities from the system. HβS preserves the structure of LiβS, and can be used for capturing and recycling lithium ions. In this work, a nanotechnological approach, called magnetic nanohydrometallurgy (MNHM), was applied to selectively extract HβS from the leached spodumene residues. Accordingly, maghemite nanoparticles functionalized with diethylenetriamine (MagNP) were employed, because of their great stability and large positive zeta potentials in the protonated form. Such nanoparticles interact strongly with the negatively charged β-spodumene particles, allowing their magnetic separation as MagNP//HβS composites. After releasing the HβS content by an acid treatment, the product was isolated in pure form and used for recovering lithium ions. This material performs with great efficiency, reaching a lithium content of 3.55% in the final composition, corresponding to 95.1% of the theoretical value (3.73%) predicted for this mineral. In comparison with the previously reported values using directly the leached spodumene residues for the capture of lithium ions, a great improvement has been achieved in this work. The MagNP//HβS composite also can be used for lithium ion capture. By increasing the HβS purity, MNHM can promote lithium recycling, in a sustainable way.

Recycling lithium and cobalt from LIBs using microwave-assisted deep eutectic solvent leaching technology at low-temperature

With the rapid development of electric vehicles and the large-scale energy storage market in recent decades, recovering valuable metals from spent LIBs has become challenging. Here, we proposed a reliable microwave-assisted deep eutectic solvents (DES) hydrometallurgy leaching method for leaching Li and Co from LiCoO2, which achieved efficient recovery at low temperatures with a low viscosity. The Li and Co extraction efficiency were close to 100% under the optimal leaching conditions of the temperature of 70 °C, leaching time of 10 min, the liquid-solid ratio of 5:0.1 g/g, and water content 10 wt% in choline chloride-formic acid DES. Furthermore, the Co could be recycled as Co3O4 by adding saturated sodium carbonate solution through the precipitation-calcination process. The addition of water can effectively reduce the viscosity of this DES and promote its flow properties. The study contains positive implications for the industrial application of eutectic solvents in the recycling of lithium-ion batteries.

Improving China’s Global Lithium Resource Development Capacity

Flourishing sales of new electric vehicles have led to a considerable surge in demand for the vital, upstream raw material, lithium (Li). As an essential energy metal and raw material for the production of batteries, lithium has become indispensable to the electric vehicle industry. It has been identified as a strategic, emerging industrial mineral in China. Based on a literature review and qualitative analysis of the imbalance between the supply and demand of lithium raw materials in China, this paper analyzes the current challenges of China’s lithium supply chain, especially mining, pricing and recycling, that are obstructing the realization of China’s carbon neutrality. On this basis, relevant policy suggestions are proposed from three perspectives: strengthening lithium resource development and reserve capacity, promoting international cooperation for lithium supply, and properly regulating the circular economy of domestic lithium resources.

Material system analysis: A novel multilayer system approach to correlate EU flows and stocks of Li‐ion batteries and their raw materials

AbstractLithium‐ion batteries (LIBs) will play a crucial role in achieving decarbonization and reducing greenhouse gases. If the EU wants to be competitive in the global market of LIBs, it has to ensure a sustainable and secure supply of the raw materials needed for the manufacturing of these batteries. Limited understanding of how the battery material cycles are linked with raw materials supply chains may hinder policy measures targeting the set‐up of a domestic supply chain in the EU since no precise information on where to intervene will be available. The novelty of this work lies in a multilayer system approach developed to reveal interlinkages between the flows of five raw materials contained in LIBs (cobalt, lithium, manganese, natural graphite, and nickel) in the EU. This was achieved by aligning material system analysis datasets of raw materials contained in LIBs with datasets on stocks and flows of this type of batteries in the EU. The results demonstrate the EU's strong import dependency on LIBs and battery raw materials. The EU recycling of lithium and natural graphite is low/nonexistent hindering the sustainable supply of these materials. The results also show that the majority of battery materials are increasingly accumulated in use or hoarding stocks. The proposed approach is designed to help identify bottlenecks and possible solutions to increase the efficiency of the EU LIB system, which could go unnoticed if each material supply chain were examined individually. This study also highlights how the lessons learned can support EU resource‐management policies.