Electrochemical Extraction Of Lithium Research Articles

The regeneration process of FePO4 in electrochemical lithium extraction: The role of alkali ions

The rapid expansion of lithium battery applications has resulted in a shortage of lithium resources, prompting researchers to focus on the electrochemical extraction of lithium from water resources using FePO4 as the host material. However, a large amount of alkali metal impurity ions in brine leads to irreversible capacity loss, limiting the industrial application of FePO4 materials in lithium extraction. The mechanism of alkali metal ions’ influence on FePO4 materials remains unclear. To address this issue, the quaternary phase diagram of FePO4-LiFePO4-NaFePO4-KFePO4 and the diffusion barriers of lithium/sodium ions in FePO4 were obtained for the first time based on the theoretical calculation of density functional theory (DFT). DFT and X-ray diffraction (XRD) refinement revealed that the inability to remove Na2/3FePO4 from the FePO4 is a critical issue affecting electrode recyclability. An innovative electrode regeneration process was proposed to enhance the lifespan of FePO4 material. The Na2/3FePO4 impurity was converted to LiFePO4 using K2S2O8 abstersion and 0.1 mol/L LiCl lithiation regeneration process. After five rounds of regenerations, the total lithium extraction of the material could still reach 80.18 % of the extraction of the brand-new electrode, demonstrating the multiple reuses of the host material and cost savings. These innovative discoveries can advance the industrial application of electrochemical lithium extraction from FePO4 electrode materials.

Continuous Flow‐By Electrochemical Reactor Design for Direct Lithium Extraction from Brines

AbstractThe demand for lithium is expected to increase significantly in the next few years, mainly due to the energy transition in the mobility sector. To electrify the entire global transportation system, it is necessary to have access to a wide variety of lithium deposits to ensure resource sovereignty and sufficient supply to meet demand. For this reason, much effort has recently been invested in developing technologies for direct lithium extraction (DLE) from brines. In this work, a membrane‐based continuous flow‐by reactor for the electrochemical extraction of lithium from brine with a LiMn2O4/λ‐MnO2 system has been studied. A zoned reactor was proposed in which the current density and electrode mass loading gradually decrease along with the depletion of lithium in the brine, obtaining an average electrode capacity of 80 mAh/g throughout three different reactor sections. The limiting Reynolds number was determined for the dilute lithium segment of the reactor to avoid mass transport limitations, with brine concentration equal to Li 3 mM and Na 1.3 M. A homogeneous cycle time was achieved for the three reactor zones and their associated average energy consumption was determined, ranging from 3.9 Wh/mol Li to 9.5 Wh/mol Li.

Progress in Electrochemical Extraction of Lithium from Seawater

Progress in Electrochemical Extraction of Lithium from Seawater

Go-encapsulated La-doped lithium manganese oxide assemblies to enhance lithium extraction performance in capacitive deionization

The electrochemical lithium extraction technique from brine has emerged as a key strategy in addressing the issue of lithium resource scarcity. Lithium manganese oxide (LMO) stands out as a typical lithium-ion selective material. Nevertheless, its lithium extraction application is restricted by inadequate conductivity and limited cycling stability. In this report, through a simple electrostatic self-assembling method, a 3-dimensional (3D) GO/La-LMO hybrid was fabricated wherein La-doped LMO (La-LMO) was enveloped by graphene oxide (GO) nanosheets. The resultant GO/La-LMO exhibited a significantly improved electrochemical behavior with fast Li+ diffusion rate and high conductivity. The GO/La-LMO hybrid demonstrated outstanding selectivity for the electrochemical intercalation/de-intercalation of Li+. As a Li+-selective cathode in capacitive deionization (CDI) device, the GO/La-LMO electrode achieved a high Li+ adsorption capacity of 1.33 mmol g−1 (10 mM LiCl) and superior selectivity with a separation factor of 126 (Mg2+/Li+ = 30, molar ratio) in Mg2+/Li+ mixed solution. The Li+ extraction percentage reached 80.4 % in the simulated salt-lake brine. Crucially, the GO/La-LMO electrode substantiated prominent structural stability and low Mn dissolution over 100 cycles, attributed to the synergistic effect of La-doping and GO capsulation to mitigate Jahn-Teller distortion. In addition, the selective adsorption–desorption mechanism of Li+ was confirmed. This work introduces a facile approach for the fabrication of robust carbon-based LMO hybrids, demonstrating the potential applications as high-performance lithium-selective materials.

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.

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 21.7mgg-1 and low energy consumption of 2.6Whmol-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.

Electrochemical lithium extraction with continuous flow electrodes

Electrochemical lithium extraction presents the advantages of superior ion selectivity and environmental friendliness. However, it faces challenges of intermittent operation, limited areal capacity and constrained mass transfer with conventional solid electrodes. In this work, we propose a continuous electrochemical lithium extraction system by using flow electrodes. Due to the inherent fluidic characteristics, the flow electrodes facilitate efficient mass transfer, thereby manifesting boosted kinetics in the insertion and extraction of lithium ions. Compared with solid electrodes, flow electrodes exhibit a substantial augmentation in lithium extraction capacity, demonstrating a nearly sixfold increase in simulated Atacama brine and a nineteen-fold in diluted Atacama saline under equivalent current density. Furthermore, we achieve a lithium production rate of 1 mol m−2 h−1 with a purity level of 0.97 at a high current density of 4 mA cm−2. These results exemplify the capability of flow electrodes for industrial-scale lithium extraction, particularly emphasizing their suitability for large-scale and high-speed production.

Electrochemical selective lithium extraction and regeneration of spent lithium iron phosphate

In this paper, a green, efficient and low-cost process for the selective recovery of lithium from spent LiFePO4 by anodic electrolysis is proposed. The leaching rates of Li, Fe and P under different conditions were explored and the optimal conditions are obtained. In the optimal conditions, Li, Fe and P leaching rates were 96.31%, 0.06% and 0.62% respectively. The Li/Fe selectivity was over 99.9%. The product obtained is isostructural FePO4 and retains the original particle morphology. The FePO4 obtained can be synthesised into LiFePO4/C by direct regeneration process or impurity removal regeneration process. The material synthesized by the latter process has a better electrochemical performance, with a discharge specific capacity of 144.5 mAh/g at 1.0C and a capacity retention of 92.0% over 500cycles. The superior performance can be attributed to an impurity removal process that reduced agglomeration and improved particle morphology.

Ionic transport kinetics of selective electrochemical lithium extraction from brines

Lithium extraction from brines by electrochemical De-intercalation/Intercalation method with LiFePO4 as host materials has attracted extensive attention, but the ionic transport properties and rate-determining step of this process are not fully understood. Therefore, to address this knowledge gap, we study the electrode process kinetics of LiFePO4/Li1-xFePO4 (0 <x < 1) in brines by electrochemical impedance spectroscopy. The results reveal that the diffusion of Li+ in electrode is the rate-determining step, the apparent diffusion coefficient DLi shows a trend of first increasing and then decreasing with the increase of electrode coating density, and the maximum value is obtained as 2.23 × 10−11 cm−2·s−1 at 55 mg·cm−2. The charge transfer resistance Rct and Warburg impedance Zω decrease with increasing temperature and do not change significantly with Li+ concentration, but Mg2+ has an inhibitory effect on Li+ charge exchange. Furthermore, the Li+ charge transfer at electrode/solution interface is differentiated for different de-lithiated Li1-xFePO4 electrodes, the Rct reaches a minimum around Li0.3FePO4. The diffusion of other competing cations is more difficult than Li+ in electrodes, which gives theoretical support for selective lithium extraction from brines from a kinetic point of view.

Facet dependent ion channel of iron phosphate for electrochemical lithium extraction

Lithium resources can be extracted from liquid by electrochemical intercalation processes. However, the response of material structure to ion transport channels in aqueous environments is not fully understood, which limits the effective design of materials. In this study, we present LiFePO4 samples with exposed (100) and (010) crystal facets (named LFP (100) and LFP (010)) as a model host to explore ion transport behavior and demonstrate the effect of exposed facet on surface adsorption and bulk phase diffusion of ions. Batch experimental results demonstrated that LFP (010), despite having a significantly smaller surface area, exhibits superior adsorption performance, with an adsorption capacity of 11.13 mg/g in a 50 ppm Li+ solution. Computational investigation reveals that due to the different exposed facets, the adsorption energy of Li(H2O)4+ on the LFP (010) is higher, but the immigration energies of Li+ in LFP (010) bulk phase are significantly lower (0.12 eV), leading to different adsorption rates at different time intervals. All these findings suggest that the adsorption process of Li+ is significantly crystal facet dependent, influenced by the adsorption energy and migration pathway, reflected in two stages of Li+ surface adsorption and bulk phase migration. These findings contribute to a better understanding of the interface interaction between Li+ and the adsorbent at the microscopic level and facilitate the design of more efficient adsorbents.

Multifunctional AlPO4 reconstructed LiMn2O4 surface for electrochemical lithium extraction from brine

LiMn2O4 (LMO) electrochemical lithium-ion pump has gained widespread attention due to its green, high efficiency, and low energy consumption in selectively extracting lithium from brine. However, collapse of crystal structure and loss of lithium extraction capacity caused by Mn dissolution loss limits its industrialized application. Hence, a multifunctional coating was developed by depositing amorphous AlPO4 on the surface of LMO using sol-gel method. The characterization and electrochemical performance test provided insights into the mechanism of Li+ embedment and de-embedment and revealed that multifunctional AlPO4 can reconstruct the physical and chemical state of LMO surface to improve the interface hydrophilicity, promote the transport of Li+, strengthen cycle stability. Remarkably, after 20 cycles, the capacity retention rate of 0.5AP-LMO reached 93.6% with only 0.147% Mn dissolution loss. The average Li+ release capacity of 0.5AP-LMO//Ag system in simulated brine is 28.77 mg/(g h), which is 90.4% higher than LMO. Encouragingly, even in the more complex Zabuye real brine, 0.5AP-LMO//Ag can still maintain excellent lithium extraction performance. These results indicate that the 0.5AP-LMO//Ag lithium-ion pump shows promising potential as a Li+ selective extraction system.

Electrochemical recovery of lithium from brine by highly stable truncated octahedral LiNi0.05Mn1.95O4

Lithium extraction from salt lakes has become a hot research issue in recent years, and LiMn2O4-based electrochemical lithium extraction is considered to be one of the most promising technologies for application. However, LiMn2O4 limits its further application due to the dissolution of Mn and the Jahn-Teller effect. In this study, a LiNi0.05Mn1.95O4 (LNMO-0.05) lithium-extraction electrode material with truncated octahedral characteristics was prepared. The special crystal surface structure enhanced the diffusion and adsorption rates of Li+, whereas Ni doping effectively suppressed the Jahn-Teller effect, and the two mechanisms synergistically enhanced the lithium extraction performance of LMO. In lithium extraction from East Taijiner brine with an Mg/Li ratio of 46, LNMO-0.05 showed excellent ion selectivity (αMg-Li = 214.08), high lithium extraction capacity (20.99 mg/g) and no significant capacity decay occurred after 10 cycles. These excellent properties make the LNMO-0.05 electrode suitable for industrial electrochemical lithium extraction.

Tailored LMO@COF composite electrodes for direct electrochemical lithium extraction from high-temperature brines

Tailored LMO@COF composite electrodes for direct electrochemical lithium extraction from high-temperature brines

Prussian blue analogue derived 3D hollow LiCoMnO4 nanocube for selective extraction of lithium by pseudo-capacitive deionization

Facing the huge demand of lithium resources in the green energy-oriented international development, the electrochemical lithium extraction technology is becoming one of the most popular way for lithium recovery from salt-lake brine or seawater. In this work, a novel LiCoMnO4 (LCMO) nanocube was facilely obtained by one-pot synthesis in the presence of Mn,Co-based bimetallic Prussian blue analogue (MnCo-PBA) and LiOH. The well-defined LCMO nanocube with unique hollow three-dimensional (3D) configuration was composed of small spinel structural LCMO nanocrystals with the particle size of 150 nm. In contrast with the LCMO block material, the specific surface area of LCMO nanocube increased, and the corresponding electrochemical activity enhanced significantly. As a Li+-selective cathode in capacitive deionization (CDI) device, LCMO nanocube exhibited high selectivity for Li+ extraction with excellent cycling stability. The Li+ adsorption amount achieved 700 μmol g−1, with the separation factor αMg2+Li+ of 88.7 (CMg2+/CLi+ = 30). The LCMO-based pseudo-CDI system was proved to be effective for Li+ extraction from the real salt-lake brine. This study delivered a new strategy for constructing a 3D porous Li+-intercalation material for Li recovery and beyond.

Electrochemical Lithium Extraction with Gas Flushing of Porous Electrodes.

Electrochemical extraction of lithium from seawater/brine is receiving more and more attention because of its environment-friendly and energy-saving features. In this work, an electrochemical lithium extraction system with gas flushing of porous electrodes is proposed. We verified that the operation of multiple gas washes can significantly reduce the consumption of ultrapure water during the solution exchange and save the time required for the continuous running of the system. The water consumption of multiple gas flush operations is only 1/60 of that of a normal single flush to obtain a purity close to 100% in the recovery solution. By comparing the ion concentration distribution on the electrode surface in flow-through and flow-by-flow modes, we demonstrate that the flow-through mode performs better. We also verified the lithium extraction performance of the whole system, achieving a purity close to 100% and average energy consumption of 0.732 kWh∙kg-1 in each cycle from the source solution of the simulated Atacama salt lake water. These results provide a feasible approach for the large-scale operation of electrochemical lithium extraction from seawater/brine.

Particle size control and electrochemical lithium extraction performance of LiMn2O4

With the unprecedented heat of lithium resources, it has been a hot topic to find an effective, low-energy-consumption, and eco-friendly method for extracting lithium from salt lakes. As an electrochemically active material, LiMn2O4(LMO) is widely used in electrochemical lithium extraction. In order to reduce the Mn dissolution loss and improve the cycle stability of LMO, we designed octahedral LMO with controllable particle size by adjusting the water/ethanol volume ratio of the precursor solution. Through the electrochemical performance test, it was found that with the increase in particle size, the cycle stability of LMO and the lithium ion transport performance also improved. The Mn dissolution loss per 30 cycles of LMO (B-LMO) was 0.187%, and the capacity was maintained at the initial 86.9%. The electrochemical lithium extraction system of B-LMO//Ag exhibits excellent lithium extraction performance. After 1 h of extraction, the lithium extraction capacity is 20.6 mg/g, and the energy consumption is 15.2 Wh/mol.

Electrochemical recovery lithium from brine via taming surface wettability of regeneration spent batteries cathode materials

Lithium-ion batteries are ubiquitous as energy storage technology in mobile electronics and hybrid electric vehicles. There is a necessity to develop new lithium extraction technologies to meet growing demand and diversify the global lithium supply chain. Electrochemical recovery is a promising method of Li+ extraction that is highly lithium selective, environmentally friendly and economical. In this work, the hydrophilicity of ZnO-coated LiMn2O4 (derived from regenerated lithium-ion battery cathode materials, rLMO) is modulated to construct electrochemical systems for the recovery of lithium from brine. The effects of current density, potential, the concentration of simulated brine, and the concentration of recovery solution on lithium extraction from the simulated brine are investigated via the response surface methodology-central composites design. The structure and morphology of the materials during lithium extraction were studied using SEM, TEM, XRD and Raman, and the electrochemical lithium extraction performance was investigated by cyclic voltammetry, galvanostatic and constant voltage. rLMO with Li vacancies has the dual functions of selective lithium extraction and ZnO coating to adjust the interface hydrophilicity, which can effectively improve the electrochemical performance. The average electro-adsorption capacity of the ZnO-modulate rLMO was 13.12 mg/g/cycle over five cycles. In the high-concentration feed solution (240 mM), the maximum adsorption capacity was 41.06 mg/g.

Construction of porous disc-like lithium manganate for rapid and selective electrochemical lithium extraction from brine

In order to satisfy the growing global demand for lithium, selective extraction of lithium from brine has attracted extensive attention. LiMn 2 O 4 -based electrochemical lithium recovery system is one of the best choices for commercial applications because of its high selectivity and low energy consumption. However, the low ion diffusion coefficient of lithium manganate limits the further development of electrochemical lithium recovery system. In this work, a novel porous disc-like LiMn 2 O 4 was successfully synthesized for the first time via two-step annealing manganese (II) precursors. The as-prepared LiMn 2 O 4 exhibits porous disc-like morphology, excellent crystallinity, high Li + diffusion coefficient (average 7.6×10 −9 cm 2 ∙s −1 ), high cycle stability (after 30 uninterrupted extraction and release cycles, the crystal structure hardly changed) and superior rate capacity (93.5% retention from 10 mA∙g −1 −120 mA∙g −1 ). The porous structure and disc-like morphology further promote the contact between lithium ions and electrode materials. Therefore, the assembled electrochemical lithium extraction device with LiMn 2 O 4 as positive electrode and silver (Ag) as negative electrode can realize the rapid and selective extraction of lithium in simulated brine (adsorption capacity of lithium can reach 4.85 mg∙g −1 in 1 h). The mechanism of disc-like LiMn 2 O 4 in electrochemical lithium extraction was proposed based on the analysis of electrochemical characterization and quasi in situ XRD. This novel structure may further promote the practical application of electrochemical lithium extraction from brine.

Modeling and performance predictions of electrochemical lithium extraction: Impact of leakage current

A comprehensive and practical model is important to the emerging electrochemical lithium extraction technology. In this study, an electrochemical model including leakage current for a LiMn2O4/Ag lithium extraction system is developed. With the consideration of leakage current, the Coulombic efficiency is below unity during charging, and the amount of lithium insertion during discharging increases, which make the model more practical and functional. The practicability of the model is validated by employing pulse and constant current profiles in charge/discharge process. It is found that the pulse current profile exhibits better electrochemical performance because of the lower overpotential, which shows higher Coulombic efficiency during charging and more lithium insertion during discharging. These simulation results fit well with experiment, demonstrating that the model with leakage current can predict the performance of different operation modes. This work may offer valuable consultation and guidance for future implementations of electrochemical lithium extraction from seawater and brine.

Island-like CeO2 decorated LiMn2O4: Surface modification enhancing electrochemical lithium extraction and cycle performance

Extracting lithium from salt lakes is an effective way to relieve the shortage of lithium resources. Electrochemical lithium extraction has attracted wide attention due to its high selectivity, eco-friendliness, and high-efficiency. Functional surface coating is an effective approach to improve the cycling performance, stability, and conductivity of the electroactive materials. In this work, LiMn2O4 (LMO) electrode materials were prepared via sol–gel method with island-like CeO2 coating (CeLMO) for lithium electrochemical adsorption from simulated brine. CeO2 is helpful to inhibit the agglomeration of active metal oxides and promote the contact and electron transfer between metal oxides. Based on the results from X-ray diffraction, X-ray photoelectron, and Raman spectroscopy, the fate of lithium intercalation and deintercalation in CeLMO is illuminated. CeLMO-2//Ag electrochemical system can produce 96% pure Li+ from Li2CO3 precipitated mother liquor, and the adsorption capacity is 36.52 mg·g−1. The capacity retention after 30 cycles was 60% at 50 mA·g−1, and the Mn dissolution loss rate is 0.016%. In summary, island-like oxide coating improves electrochemical lithium adsorption efficiency and is a promising technology for producing battery-grade lithium products.