Lithium Leaching Research Articles

Active Corrosion Protection by Epoxy Coating on Li2CO3-Pretreated Anodized Aluminum Alloy 2024-T3

The fast leaching and robust barrier property of inhibitors are the basic fundamentals for the formation of active protective coatings to protect aluminum alloys. Herein, an active protective surface was developed based on an epoxy coating and an underlying lithium carbonate (Li2CO3)-treated anodized aluminum alloy 2024-T3. The morphology of the Li-LDH layer was studied to know its formation mechanism. The electrochemical studies revealed that the fast and adequate leaching of lithium led to a substantial increment of corrosion resistance of the scratched coating in 3.5 wt% NaCl from 1 to 8 days. Time of flight secondary ion mass spectroscopy (ToF-SIMS) results indicated that Li was distributed in the lateral direction and covered the scratched area. The 3D images indicated that different lithium compounds were formed and 90% of the scratched area was covered with the lithium protective layer over immersion time. A combined approach of morphology observations, electrochemical measurements, and ToF-SIMS showed the lithium protective layer offered good corrosion resistance. On the contrary, lithium provided fast and adequate leaching from the coating, demonstrating good active protection for aluminum and its alloys.

A Study on Optimization of Nitric Acid Leaching and Roasting Process for Selective Lithium Leaching of Spent Batreries Cell Powder

A Study on Optimization of Nitric Acid Leaching and Roasting Process for Selective Lithium Leaching of Spent Batreries Cell Powder

Efficient recovery and regeneration of waste graphite through microwave stripping from spent batteries anode for high-performance lithium-ion batteries

Green and efficient separation of waste graphite (WG) from the copper foil of spent lithium-ion batteries (LIBs) anode can significantly reduce the pollution caused by the LIBs anode and relieve the pressure of graphite demand. Here, a clever technique for the excellent microwave absorption ability of LIBs anode makes the binder and electrolyte in WG volatilize quickly in the microwave field, resulting in an efficient separation of WG from the copper foil. In addition, microwave radiation also causes the remaining lithium in WG to form Li2CO3, which can be extracted by water leaching under CO2 and then heating, lithium-containing wastewater can also be recycled for the leaching of lithium. The purity of reconstituted graphite (RG) is improved after water leaching and heating, and the content of fluorine impurity is reduced from 15.87% to 0.28%. RG also retains the orderly layered structure and restores the electrochemical activity, the initial discharge specific capacity and coulombic efficiency at 0.1 C are 435.2 mAh·g−1 and 80.6%, respectively. Moreover, it reveals the superior cycling stability and rate performance comparable with commercial graphite. The proposed method provides an industrialized, low-energy-consumption pathway for the clean recovery and re-use of spent LIBs anode, which provides a reference basis for the disposal of other hazardous carbon-containing solid wastes.

Lithium extraction from clay-type lithium resource using ferric sulfate solutions via an ion-exchange leaching process

Clay-type lithium resources have been developed as an important natural lithium source secondary to hard rock sources and brine sources. In this study, a green and effective lithium extraction process employing ferric salt solutions to leach lithium-rich clay was proposed. Upon calcination treatment, 73.6% of lithium could be leached over a period of 180 min using a 15% ferric sulfate solution at 90 °C. The most suitable calcination temperature, leaching temperature, ferric sulfate concentration, and reaction time were determined to be 600 °C, 90 °C, 15% ferric sulfate, and 180 min, respectively. Ferric chloride and ferric nitrate had similar lithium leaching efficiencies under the same conditions. In addition, ferrous, sodium and calcium salts were introduced and compared in terms of their lithium extraction abilities. The results indicated that ferric ions had good selectivity for lithium leaching. The leaching process was considered to involve ion exchange between ferric ions and lithium ions.

Preparation of Battery-Grade Lithium Carbonate with Lithium-Containing Desorption Solution

In this study, a process for preparing battery-grade lithium carbonate with lithium-rich solution obtained from the low lithium leaching solution of fly ash by adsorption method was proposed. A carbonization-decomposition process was carried out to remove impurities such as iron and aluminum. First, primary Li2CO3 was treated by CO2 to get the more soluble bicarbonates. The decomposition of LiHCO3 produced insoluble Li2CO3 at 90 °C And Li2CO3 was smashed by air stream pulverization. The final precipitation yielded a high purity (99.6%) and homogeneous Li2CO3. Some factors affecting production efficiency were investigated. The results showed that a liquid-solid ratio of 25:1, a carbonization temperature of 25 °C, an air velocity of 2 L/min, and a stirring speed of 400 rpm; a decomposition temperature of 90 °C and a stirring speed of 400 rpm, a molar ratio of EDTA to Ca 2:1; an air pressure of 0.3 MPa and hot water washing precipitate (L/S mass ratio 2:1) promoted ions removal.

Temperature dependent lithium isotope fractionation during glass dissolution

Understanding the mechanisms by which borosilicate glasses corrode in contact with aqueous solutions remains a challenge to the safety case for the geological disposal of vitrified high-level nuclear waste. Here, lithium isotope fingerprinting techniques were applied to the leachates of a simulant Magnox waste glass to probe the mechanisms of aqueous corrosion at both short and long timescales (6 hours to 464 days). Experiments took place at 40 and 90 °C to assess the consistency of the dissolution mechanisms across a range of commonly employed temperatures and the legitimacy of applying higher temperature experimental datasets to understand glass corrosion within a disposal facility at lower temperatures.Two competing release mechanisms were observed for lithium (diffusion and hydrolysis), and the relative proportions of these mechanisms changed through time. Leachates initially had lower δ7Li values than the pristine glass (−2.7‰ at 40 °C and −1.1‰ at 90 °C relative to the pristine glass) at both temperatures due to lithium leaching incongruently through diffusive processes. The greater offset between solution and solid at lower temperatures indicates a larger rate of diffusion (incongruent dissolution) relative to the rate of hydrolysis (congruent dissolution) at lower temperatures. The fraction of lithium released through diffusion relative to the fraction of lithium released through hydrolysis then increased at both temperatures with time up to 126 days, increasing from 0.47 and 0.22 at 6 hours to 0.66 and 0.41 at 126 days at 40 and 90 °C respectively. Subsequently, the fractions of lithium released through diffusion sharply decreased to 0.36 at 40 °C and 0.22 at 90 °C after 464 days, consistent with network hydrolysis coupled with secondary phase precipitation later controlling the long-term release of Li at both temperatures. Throughout the duration of the experiments (464 days) the δ7Li values in solution increased to 9.0‰ at 40 °C and 10.0‰ at 90 °C due to the formation of talc and montmorillonite phases at 40 °C and additional smectite phases at 90 °C. Further, no evidence for the formation of a diffusive barrier to the transport of Li within the alteration layers became apparent during the later stages of dissolution at either temperature. However, the fraction of lithium leached through diffusion was still significant throughout all stages of dissolution. Lithium isotope ratios in solution were correlated with the transition from a system which was increasingly dominated by lithium diffusion as the dissolution rate slowed to one which was controlled by hydrolysis coupled with secondary phase precipitation at long durations. Alongside elemental ratios in solution, these results were consistent with the same set of mechanisms governing dissolution across the temperature range studied.

Study on Roasting for Selective Lithium Leaching of Cathode Active Materials from Spent Lithium-Ion Batteries

Recently, many studies have been conducted on the materialization of spent batteries. In conventional cases, lithium is recovered from an acidic solution through the leaching and separation of valuable metals; however, it is difficult to remove impurities because lithium is recovered in the last step. Cathode active materials of lithium-ion batteries comprise oxides with lithium, such as LiNixCoyMnzO2 and LiCoO2. Thus, lithium should be converted into a compound that can be leached in deionized water for selective lithium leaching. Recent studies on the leaching and recovery of Li2CO3 through a carbon reduction reaction show low economic efficiency, due to the solubility of Li2CO3 at room temperature being as low as 13 g/L. This paper proposes a method of roasting after nitric acid deposition for selective lithium leaching and recovery to LiNO3. Based on experiments involving the varying of the amount of nitric acid, roasting temperature, and solid–liquid ratio, optimal values were found to be dipping in 10 M HNO3 2 mL/g, roasting at 275 °C, and deionized water with a solid–liquid ratio of 10 mL/g, respectively. Over 80% Li leaching was possible under these conditions. IC analysis confirmed that the purity was 97% lithium nitrate.

In situ observation of thermal-driven degradation and safety concerns of lithiated graphite anode

Graphite, a robust host for reversible lithium storage, enabled the first commercially viable lithium-ion batteries. However, the thermal degradation pathway and the safety hazards of lithiated graphite remain elusive. Here, solid-electrolyte interphase (SEI) decomposition, lithium leaching, and gas release of the lithiated graphite anode during heating were examined by in situ synchrotron X-ray techniques and in situ mass spectroscopy. The source of flammable gas such as H2 was identified and quantitively analyzed. Also, the existence of highly reactive residual lithium on the graphite surface was identified at high temperatures. Our results emphasized the critical role of the SEI in anode thermal stability and uncovered the potential safety hazards of the flammable gases and leached lithium. The anode thermal degradation mechanism revealed in the present work will stimulate more efforts in the rational design of anodes to enable safe energy storage.

Enhanced lithium leaching from lepidolite in continuous tubular reactor using H2SO4+H2SiF6 as lixiviant

An acidic mixture of sulfuric and fluosilicic acid (H2SO4+H2SiF6) was employed as lixiviant to enhance leaching of lithium from lepidolite. The H2SiF6 was obtained as a byproduct of anhydrous hydrofluoric acid production, aiming to provide HF molecules. It was found that the HF molecules were the main reaction component and played a key role in strengthening the dissolution of lepidolite. Different factors, including mass ratio of ore/H2SO4/H2SiF6, concentrations of H2SO4 and H2SiF6, leaching temperatures (40−80 °C) and time (15−75 min), were investigated. Moreover, an efficient tubular reactor was employed to improve this acid leaching system. Under the optimal conditions (ore/H2SO4/H2SiF6 mass ratio of 1:0.8:1.6, 80 wt.% H2SO4, 15 wt.% H2SiF6, 80 °C, 15 min), 97.9% of Li, 96.4% of K, 97.6% of Rb, 96.7% of Cs and 81.4% of Al (mass fraction) were leached. Additionally, a two-step thermal process was proposed to remove fluorine of leaching slurry. This acid treatment using an acidic mixture of H2SO4 and H2SiF6 in a continuous tubular reactor shows potential as an alternative process to extract lithium from lepidolite.

Laterally-resolved formation mechanism of a lithium-based conversion layer at the matrix and intermetallic particles in aerospace aluminium alloys

Lithium leaching coatings have recently been developed as eco-friendly active corrosion protection technology for aerospace aluminium alloys (AAs) by the formation of a conversion layer at coating defects. While general conversion layer formation characteristics were studied and reported before, here we study the local layer formation process with sub-micron resolution at and around intermetallic particles (IMPs) in AA2024-T3. Top- and cross-sectional-view morphological electron micrograph observations along with open circuit potential (OCP) measurements are performed, mimicking coating defect conditions upon lithium carbonate leaching from the coating matrix. The results revealed five stages of the conversion process in which the alloy matrix and different IMPs evolve morphologically, compositionally, and electrochemically. Besides, we found a correlation between the OCP response of the AA2024-T3 system and the morphological and compositional evolutions of the alloy matrix and IMPs at different stages of exposure. Passive layer and alloy matrix dissolution leading to surface Cu-enrichment and S-phase dealloying occur at early stages of exposure. They precede the formation of a columnar layer on the alloy, followed by the establishment of a dense-like layer at the final stage. Dealloying of Al2CuMg can assist the conversion process by providing local supersaturation. Through complementary experiments in a sodium carbonate solution and besides X-ray diffraction analysis, we found out that lithium plays a critical role in stabilising the corrosion product throughout the conversion process.

A fast and efficient method for selective extraction of lithium from spent lithium iron phosphate battery

A new recovery method for fast and efficient selective leaching of lithium from lithium iron phosphate cathode powder is proposed. Lithium is expelled out of the Oliver crystal structure of lithium iron phosphate due to oxidation of Fe 2 + into Fe 3 + by ammonium persulfate. 99% of lithium is therefore leached at 40 °C with only 1.1 times the amount of ammonium persulfate without the help of acid treatment. The use of ammonium persulfate also avoids the necessity to remove other metal ions in the later purification process. Various characterization methods including SEM, XPS, XRD are used to explore the experimental leaching mechanism. Theoretical investigations are performed which reveals the E-pH diagram of Fe–P–Li–H 2 O thermodynamic equilibrium. It confirms the possibility and suggests appropriate pH range allowing direct conversion from lithium iron phosphate to iron phosphate with great energy saving and reduced use of acid and base. Based on the experimental and theoretical results, a green and efficient closed-loop recycling route for lithium iron phosphate is proposed. • A fast efficient leaching of LiFePO 4 is achieved via oxidation by (NH 4 ) 2 S 2 O 8 . • 99% of lithium is leached without acid due to oxidation of LiFePO 4 to FePO 4 . • Mechanism studies are conducted to establish principles for recycling LiFePO 4 .

Hydrometallurgical enhanced liberation and recovery of anode material from spent lithium-ion batteries

The efficient recycling of spent anode material (SAM) from spent lithium-ion batteries (LIBs) is generally critical in terms of electronic waste recyclingas well as increasing resource shortage and environmental problems. This research reported a novel and green method to recycle lithium, copper foil, and graphite from SAM by water leaching treatment. The results indicated that 100% of graphite was exfoliated from the anode material and 92.82% leaching efficiency of lithium was obtained under the optimal conditions of 80 °C, 60 g/L, 300 rpm, and 60 min, respectively. This finding revealed that the SAM got a full liberation characteristic due to the removal of binder, which produced an ideal leaching lithium efficiency rivaling the acids’ performance. The mechanism of the liberation of SAM and lithium leaching is presented based on the analysis of results. The graphite was purified and recovered after water leaching treatment. Besides, lithium was recovered in the form of lithium carbonate (Li2CO3), and the copper foil was recovered in a sheet. This study endeavors to develop an economical and environmentally feasible plan to recycle graphite, copper, and lithium from SAM.

The Systematics of Chlorine, Lithium, and Boron andδ37Cl,δ7Li, and δ11B in the Hydrothermal System of the Yellowstone Plateau Volcanic Field

AbstractChlorine, lithium, and boron are trace elements in rhyolite but are enriched in groundwater flowing through rhyolite because they tend to partition into the fluid phase during high‐temperature fluid‐rock reactions. We present a large data set of major element and δ37Cl, δ7Li, and δ11B compositions of thermal water and rhyolite from Yellowstone Plateau Volcanic Field (YPVF). The Cl/B, Cl/Li, δ37Cl (−0.2‰ to +0.7‰), and δ11B (−6.2‰ to −5.9‰) values of alkaline‐chloride thermal waters reflect high‐temperature leaching of chlorine, lithium, and boron from rhyolite that has δ37Cl and δ11B values of +0.1‰ to +0.9‰ and −6.3‰ to −6.2‰, respectively. Chlorine and boron are not reactive, but lithium incorporation into hydrothermal alteration minerals result​s in a large range of Cl/Li, B/Li, and δ7Li (−1.2‰ to +3.8‰) values in thermal waters. The relatively large range in δ7Li values of thermal waters reflects a large range of values in rhyolite. Large volumes of rhyolite must be leached to account for the chloride, lithium and boron fluxes, implying deep groundwater flow through rhyolite flows and tuffs representing Yellowstone's three eruptive cycles (∼2.1 Ma). Lower Cl/B values in acid‐sulfate waters result from preferential partitioning of boron into the vapor phase and enrichment in the near‐surface water condensate. The Cl/B, Cl/Li, δ7Li (−0.3‰ to +2.1‰), and δ11B (−8.0‰ to −8.1‰) values of travertine depositing calcium‐carbonate thermal waters which discharge in the northern and southern YPVF suggest that chlorine, lithium, and boron are derived from Mesozoic siliciclastic sediments which contain detrital material from the underlying metamorphic basement.

Green extraction of lithium from waste lithium aluminosilicate glass-ceramics using a water leaching process

An acid-free leaching process for lithium extraction from waste lithium aluminosilicate (LAS) glass-ceramics was investigated. Lithium was extracted by a water leaching process after calcination with CaO or a CaO-CaCl2 mixture. Compared to extraction using only CaO calcination, the addition of CaCl2 to CaO can significantly reduce the Si:Ca mixing ratio as well as the thermal treatment temperature. A drastic decrease in thermal treatment and leaching time was observed during the experiments. Based on thermodynamics calculations and X-ray diffraction analysis, the crystalline phase that determined the lithium extraction mechanism was investigated. In substituting CaO with CaCl2, the lithium leaching rate initially decreased or remained constant due to a decrease in the LiAlO2 phase. However, the lithium leaching rate gradually increased with increasing CaCl2 substitution rate, caused by an increase in the formation of the LiCl phase. In addition to lithium, calcium and chloride were also observed during the water leaching process. The leaching rate was independent of the thermal treatment and leaching time. Considering conventional lithium purification techniques, a green process for lithium extraction, purification, and recovery from waste LAS glass-ceramics is proposed.

Early-Stage Recovery of Lithium from Tailored Thermal Conditioned Black Mass Part I: Mobilizing Lithium via Supercritical CO2-Carbonation

In the frame of global demand for electrical storage based on lithium-ion batteries (LIBs), their recycling with a focus on the circular economy is a critical topic. In terms of political incentives, the European legislative is currently under revision. Most industrial recycling processes target valuable battery components, such as nickel and cobalt, but do not focus on lithium recovery. Especially in the context of reduced cobalt shares in the battery cathodes, it is important to investigate environmentally friendly and economic and robust recycling processes to ensure lithium mobilization. In this study, the method early-stage lithium recovery (“ESLR”) is studied in detail. Its concept comprises the shifting of lithium recovery to the beginning of the chemo-metallurgical part of the recycling process chain in comparison to the state-of-the-art. In detail, full NCM (Lithium Nickel Manganese Cobalt Oxide)-based electric vehicle cells are thermally treated to recover heat-treated black mass. Then, the heat-treated black mass is subjected to an H2O-leaching step to examine the share of water-soluble lithium phases. This is compared to a carbonation treatment with supercritical CO2, where a higher extent of lithium from the heat-treated black mass can be transferred to an aqueous solution than just by H2O-leaching. Key influencing factors on the lithium yield are the filter cake purification, the lithium separation method, the solid/liquid ratio, the pyrolysis temperature and atmosphere, and the setup of autoclave carbonation, which can be performed in an H2O-environment or in a dry autoclave environment. The carbonation treatments in this study are reached by an autoclave reactor working with CO2 in a supercritical state. This enables selective leaching of lithium in H2O followed by a subsequent thermally induced precipitation as lithium carbonate. In this approach, treatment with supercritical CO2 in an autoclave reactor leads to lithium yields of up to 79%.

Design Optimization of Selective Lithium Leaching of Cathodic Active Materials from Spent Lithium-Ion Batteries Based on the Taguchi Method

The use of lithium-ion batteries (LIBs) has increased in recent years. Thus, efficient recycling is important. In this study, the Taguchi method was used to find the optimal selective lithium leaching parameters for spent LIB recycling. Orthogonal array, signal-to-noise ratio, and analysis of variance were employed to investigate the optimization of selective lithium leaching. The experimental parameters were heat treatment and leaching conditions. The lithium leaching ratio was analyzed by inductively coupled plasma (ICP). The reaction temperature was analyzed by thermogravimetry differential scanning calorimetry (TG-DSC) using lithium cobalt oxide (LCO) and carbon powder, and X-ray diffraction (XRD) was performed after heat treatment at different temperatures. From the XRD analysis, a Li2CO3 peak was observed at 700 °C. After heat treatment at 850 °C, a peak of Li2O was confirmed as Li2CO3 decomposed into Li2O and CO2 over 723 °C. The Li2O reacts with Co3O4 at a high temperature to form LCO. The phase of lithium in the LIB changes according to the conditional heat treatment, affecting the lithium leaching rates. As heat treatment conditions, N2 atmosphere combined with 700 °C heat treatment is suitable, and the solid–liquid ratio is important as a leaching factor for selective lithium leaching.

Al-doped H2TiO3 ion sieve with enhanced Li+ adsorption performance.

H2TiO3 (HTO) is considered to be one of the most promising adsorbents for lithium recovery from aqueous lithium resources duo to its highest theoretical adsorption capacity. However, its actual adsorption capacity is much lower owing to its unknown structure and incomplete leaching of lithium. After Al is doped into H2TiO3 (HTO-Al), the adsorption capacity of HTO-Al is 32.12 mg g−1 and the dissolution of Ti is 2.53%. HTO-Al has good adsorption selectivity, and all the separation factors α are ≫1. Furthermore, HTO-Al also exhibits good cyclic stability and solubility resistance. After 5 cycles, the adsorption capacity remains 29.3 mg g−1 and the dissolution rate is 1.7%. Therefore, HTO-Al has potential application value for recovering Li+ from aqueous lithium resources.

High-efficiency method for recycling lithium from spent LiFePO4 cathode

Abstract The extraction of Li from the spent LiFePO4 cathode is enhanced by the selective removal using interactions between HCl and NaClO to dissolve the Li+ ion while Fe and P are retained in the structure. Several parameters, including the effects of dosage and drop acceleration of HCl and NaClO, reaction time, reaction temperature, and solid–liquid ratio on lithium leaching, were tested. The Total yields of lithium can achieve 97% after extraction process that lithium is extracted from the precipitated mother liquor, using an appropriate extraction agent that is a mixture of P507 and TBP and NF. The method also significantly reduced the use of acid and alkali, and the economic benefit of recycling is improved. Changes in composition, morphology, and structure of the material in the dissolution process are characterized by inductively coupled plasma optical emission spectrometry, scanning electron microscope, X-ray diffraction, particle size distribution instrument, and moisture analysis.

Leaching of lepidolite and recovery of lithium hydroxide from purified alkaline pressure leach liquor by phosphate precipitation and lime addition

This study investigated the pressure leaching of lithium and other valuable metals from lepidolite using NaOH and Ca(OH)2. The findings showed that NaOH concentration, temperature, and stirring rate are the most significant process parameters. The addition of Ca(OH)2 facilitates the leaching of lithium and minimizes the concentration of silicate and fluoride in the leach liquor by forming solid phases identified as Ca3Al2Si3O12, CaF2 and NaCaHSiO4, with a loss of about 7% NaOH. The leaching efficiencies after 2 h were 94% Li, 98% K, 96% Rb, and 90% Cs under the most suitable conditions (250 °C, 320 g/L NaOH, liquid-to-solid ratio of 10, 300 rpm stirring speed, lime addition of 0.3 g/g). Precipitation of lithium as Li3PO4 by adding phosphoric acid and subsequent conversion of Li3PO4 to LiOH using Ca(OH)2 recovered 83% of lithium as LiOH allowing recycling the rest along with residual remnant NaOH for leaching.

Simultaneous lithium bioleaching and bioaccumulation from lepidolite using microscopic fungus Aspergillus niger

The leaching of lithium from lepidolite using the filamentous fungus Aspergilluss niger was examined. Two mechanisms were suggested – biochemical using citric acid as the main bioleaching agent and biomechanical through hyphae penetration confirmed by XRD and SEM analyses. The bioleaching processes were conducted at various glucose concentrations (5 – 20 g.L-1). The higher glucose concentration was, the higher Li bioleaching was observed. Li accumulation by fungal biomass played an important role in Li solubilisation from lepidolite. Totally, 11.5 mg of lithium were recovered from 1 kg of lepidolite by combination of bioleaching and bioaccumulation processes. As a result of bioleaching, the formation of new silicate phase of SiO2 was detected. According to the results, fungal bioleaching of Li from lepidolite can be a perspective way of Li recovery from hard-rock ores.