Search Results (245)

In this work, a method for leaching black mass from spent Li batteries using oxalic acid was developed and experimentally verified with the objective of selectively separating lithium and cobalt. Oxalic acid proved to be an efficient and selective leaching agent. Under 1 M C₂H₂O₄, 120 min, L:S = 20, 80 °C and 300 rpm, a lithium yield of 90% was achieved, while cobalt dissolution remained low at 1.57%. Subsequently, cobalt spontaneously precipitated from the leachate within several hours, and the solid phase was fully separated after 24 h. The leachate contained minor amounts of accompanying metals, with dissolution yields of 0.5% Mn, 8% Fe and 1.4% Cu. These impurities were removed from the leachate by controlled pH adjustment using NaOH at ambient temperature and 450 rpm, with complete precipitation at pH 12. This procedure generated a purified lithium-rich leachate, which was converted into lithium oxalate by crystallisation at 105 °C. Subsequent calcination of the resulting solid at 450 °C for 30 min produced Li₂CO₃ with a purity of 91%. Based on the experimental findings, a conceptual technological process for selective lithium leaching using oxalic acid was proposed, demonstrating the potential of this method for sustainable lithium recovery. Full article

The rise in electric vehicles (EVs) with lithium-ion batteries supports net-zero goals, but the increasing demand will inevitably generate more battery waste. Current pack designs often rely on permanent joining techniques, which hinder disassembly and thereby limit serviceability, reuse and recycling. A critical challenge is the removal of the battery lid, typically bonded to the pack frame with sealant adhesives. In the absence of design for disassembly requirements for OEMs, this study investigates a novel debonding strategy focused on the lid-to-frame bonding. A silane-based adhesive commonly used in battery packs is first characterised under tensile, shear and mode I conditions to establish the baseline performance in the range of flexible adhesive properties. Herein, a heat-activated primer is introduced as a debondable interfacial layer between the adhesive and the substrate. Upon activation at 150 ${}^{\circ }$C, the primer significantly reduces adhesion, around 98% of the initial joint strength, enabling room temperature debonding. The primer demonstrates strong compatibility with epoxy and polyurethane adhesives, but its performance with silane-based systems still needs to be improved in terms of the primer’s compatibility with silane-based adhesives. Finally, a small-scale testing apparatus is developed to evaluate primer effectiveness in the disassembly of battery lids. This approach represents a promising step toward more serviceable, recyclable and sustainable battery systems. Full article

Waste electrical and electronic equipment (WEEE) is one of the fastest-growing waste streams globally. Disposable e-cigarettes are among the products that have gained popularity in recent years. Their complex construction and embedded lithium-ion batteries (LIBs) present environmental, safety, and resource recovery challenges. Despite growing research interest, integrated analyses linking material composition with user disposal behavior remain limited. This study is the first to incorporate device-level mass balance, material contamination assessment, battery residual charge measurements, and user behavior to evaluate the waste management challenges of disposable e-cigarettes. A mass balance of twelve types of devices on the Polish market was performed. Plastics dominated in five devices, while non-ferrous metals prevailed in the others, depending on casing design. Materials contaminated with e-liquid residues accounted for 4.4–10.7% of device mass. Battery voltage measurements revealed that 25.6% of recovered LIBs retained a residual charge (greater than 2.5 V), posing a direct fire hazard during waste handling and treatment. Moreover, it was estimated that 7 to 12 tons of lithium are introduced annually into the Polish market via disposable e-cigarettes, highlighting substantial resource potential. Survey results showed that 46% of users disposed of devices in mixed municipal waste, revealing a knowledge–practice gap largely independent of gender or education. Integrating technical and social findings demonstrates that improper handling is a systemic issue. The findings support the relevance of eco-design requirements, such as modular casings for battery removal, alongside the enforcement of Extended Producer Responsibility (EPR) schemes. Current product fees (0.01–0.03 EUR/unit) remain insufficient to establish an effective collection infrastructure, highlighting a key systemic barrier. Full article

A treatment process was developed for effluents from direct physical lithium-ion battery (LIB) recycling with a focus on the removal of organic contaminants. The high chemical oxygen demand to biological oxygen demand ratio (COD/BOD₅) of 3.9–4.6 indicates that biological treatment is not feasible. Therefore, three advanced oxidation processes were evaluated: UV/H₂O₂ oxidation, the Fenton process and electrochemical oxidation. Two target scenarios were considered, namely compliance with the limit for discharge into the sewer system (COD = 800 mg/L) and compliance with the stricter limit for direct discharge into surface waters (COD = 200 mg/L). Under the investigated conditions, UV/H₂O₂ oxidation and the Fenton process did not meet the required discharge limits and exhibited high chemical consumption. In contrast, electrochemical oxidation achieved both discharge criteria with a lower energy demand, requiring 32.8 kWh/kgCOD_removed for sewer discharge and 95.3 kWh/kgCOD_removed for direct discharge. An economic assessment further identified electrochemical oxidation as the most cost-effective option, with treatment costs of EUR 6.63/m³, compared to EUR 17.31/m³ for UV/H₂O₂ oxidation and EUR 28.66/m³ for the Fenton process. Overall, electrochemical oxidation proved to be the most efficient and environmentally favorable technology for treating wastewater from LIB recycling, enabling compliance with strict discharge regulations while minimizing the chemical and energy demand. Full article

For the method of focused ion beam (FIB) milling to fabricate lithium tantalate (LiTaO₃) metasurfaces, the use of a Cr-Pt mask can enhance imaging contrast and enable superior drift correction. However, removing the Pt component necessitates the volatile and toxic etchant aqua regia, presenting considerable safety risks. This work introduces a novel lift-off strategy that incorporates thin Ag or Au sacrificial layers (≤30 nm) between the LiTaO₃ substrate and Cr-Pt mask. Systematic evaluation identifies Ag or Au as optimal candidates due to their high sputtering yield for efficient FIB patterning and compatibility with a low-toxicity KI + I₂ etchant. Experiments showed complete mask removal within 60 s while preserving structural fidelity: atomic force microscopy (AFM) results reveal a surface roughness comparable to conventional aqua regia processing, and scanning microscope (SEM) imaging confirms intact sidewall angles (10–11°). The second-harmonic generation (SHG) measurements reveal comparable optical performance upon the introduction of Ag or Au sacrificial layers. This approach eliminates hazardous etchant and maintains process precision, offering a scalable and safer fabrication route for LiTaO₃-based photonic devices. Full article

This study presents an approach to synthesizing LTA-type zeolite from spodumene residue generated during a lithium extraction process. A residue was obtained after leaching β-spodumene with 2 mol/L phosphoric acid. After solid–liquid separation, the delithiated residue was first treated with 2 mol/L sodium hydroxide and then subjected to hydrothermal synthesis using sodium aluminate as an additional aluminum source. The resulting material was characterized by XRD, SEM-EDS, XPS, and FTIR, which collectively confirmed the formation of a crystalline material exhibiting the structural features, elemental composition, and morphological characteristics consistent with LTA-type zeolite. Additional analyses, including BET surface area, particle size distribution, and zeta potential measurements, were performed to further evaluate the physicochemical properties of the synthesized zeolite. The spodumene leach residue (SLR)-derived zeolite was further tested for its adsorption performance in heavy metal ions removal from a mixed ion solution containing Pb²⁺, Cu²⁺, Zn²⁺, and Ni²⁺ ions. The zeolite demonstrated a high selectivity for Pb²⁺, followed by moderate uptake of Cu²⁺, while Zn²⁺ and Ni²⁺ adsorption was minimal. These findings demonstrate that spodumene residue, a waste by-product of lithium processing, can be effectively upcycled into LTA zeolite suitable for heavy metal remediation in water treatment applications. Full article

The well-balanced combination of high energy density and competitive cycle performance has established lithium-ion batteries as the technology of choice for Electric Vehicles (EVs) energy storage. Nevertheless, battery degradation continues to pose challenges to EV range, safety, and long-term reliability, making accurate estimation of their State of Health (SoH) crucial for efficient battery management, safety, and improved longevity. This paper addresses a compelling research question surrounding the possibility of developing a real-time, non-invasive, and efficient methodology for estimating lithium-ion battery SoH without battery removal, relying solely on voltage and current data. Our approach integrates the fitting abilities of Maximum Likelihood Estimation (MLE) with the dynamic uncertainty propagation of Bayesian Filtering to provide accurate and robust online SoH estimation. By reconstructing the open-circuit voltage curve from real-time data, the MLE estimates battery capacity during discharge cycles, while Bayesian Filtering refines these estimates, accounting for uncertainties and variations. The methodology is validated using an available dataset from Stanford University, demonstrating its effectiveness in tracking battery degradation under driving profiles. The results indicate that the approach can reliably estimate battery SoH with mean absolute errors below 1%, confirming its suitability for scalable EV applications. Full article

This study undertakes a detailed computational examination of a direct refrigerant cooling approach for a 50 Ah prismatic lithium iron phosphate (LiFePO₄) battery. We conducted a systematic assessment to determine how the cooling plate’s topological layout and flow orientation influenced key performance indicators, namely thermal homogeneity, heat removal efficiency, and hydraulic pressure loss. Utilizing a validated two-phase flow model with 1,1,1,2-Tetrafluoroethane (R134a), simulations were performed on six distinct serpentine channel designs under a wide range of operating scenarios, covering variations in mass flow rate, saturation temperature, and inlet vapor quality. The simulation data revealed a strong correlation between the cooling plate’s geometric parameters and the system’s thermal behavior. In terms of uniformity, the optimized Case 6 configuration significantly outperformed Case 2, achieving a 76% improvement by narrowing the maximum mid-plane temperature difference from 2.02 °C down to 0.48 °C. A trade-off was observed regarding the mass flow rate: while higher rates lowered the peak temperature by approximately 18%, they simultaneously led to increased hydraulic pressure loss and slight non-uniformity. Similarly, decreasing the saturation temperature improved heat extraction but exacerbated flow resistance. Notably, this study identified an inlet vapor quality of 0.1 as the optimal point for maximizing temperature uniformity. These insights provide a robust theoretical foundation for optimizing the design and operation of compact direct refrigerant-based BTMSs. Full article

During the recycling process of spent lithium-ion batteries (LIBs), there is a large number of fluoride ions in the leaching solution. These fluoride ions not only affect the quality of lithium products, but they also have adverse effects on the environment. Therefore, the efficient and deep removal of the characteristic pollutant fluoride ions is currently a hot topic in the field of recycling spent LIBs. In this study, a porous zirconium-based adsorbent was prepared and its adsorptive properties were characterized. Due to the excellent affinity between zirconium and fluorine, the zirconium-based adsorbent exhibited excellent adsorption performance in the leaching solution of spent lithium iron phosphate (SLFP) batteries. Under the optimal adsorption conditions, the adsorption capacity reached 113.78 mg/g, and it surpassed most commercial adsorbents. The zirconium-based adsorbent followed the Langmuir isotherm model for fluoride adsorption with correlation coefficients consistently exceeding 0.95, and exhibited pseudo-second-order kinetics, demonstrating goodness-of-fit values above 0.998. The negative Gibbs free energy change thermodynamically confirms the spontaneous nature of the adsorption process. The structure of the adsorbent before and after adsorption was characterized, and the adsorption mechanism was elaborated in detail. Furthermore, the influence of the coexistence of different anions on the adsorption of fluoride ions by zirconium-based adsorbent was studied in a real leaching solution from SLFP calcine. This study provides a feasible approach to deep defluoridation for leachate from spent LIBs, and has the advantages of simple operation and high adsorption capacity. Full article

Lithium is a metal of particular interest due to its growing industrial use. However, concerns have been raised about its potential impact on the environment. A notable demand for sustainable technologies to remove Li from environmental matrices and possibly recover it for re-utilization is occurring. Plants can be successfully targeted for this purpose, but further research is needed to expand knowledge. In this regard, laboratory studies under full control of the parameters affecting plant performances are very helpful to obtain insight on the matter. This study investigated the potential of hemp (Cannabis sativa L.) plants to tolerate and accumulate Li in their organs under hydroponic conditions, evaluating morphological, physiological and ionomic parameters. Hemp plants were exposed for 10 days to different LiCl concentrations (0, 50, 150 and 300 mg L⁻¹). The results show the toxicity of the metal at the highest concentration tested (150 and 300 mg L⁻¹ LiCl), causing a reduction in biomass and pigment content (evaluated by spectral reflectance), as well as an uneven impairment of the photosynthetic processes across the leaf lamina (highlighted by the imaging of chlorophyll fluorescence). The ionomic analysis revealed the increase in some micronutrients (Na, Mn, Zn, Mo and Co), which may be involved in the plant’s response to stress conditions at the highest tested Li concentration. Despite accumulating up to 500 mg kg⁻¹ of Li in their aerial organs, hemp plants exposed to 50 mg L⁻¹ LiCl did not exhibit any toxic effects at biometric and physiological levels. These results open up interesting perspectives for the use of this plant species for phytoremediation and metal recovery from biomass, in line with the EU regulations requiring environmentally sustainable practices. Full article

Accurate prediction of the State of Health (SOH) of lithium-ion batteries is essential for improving the safety and longevity of energy storage systems. This paper introduces ExpertMixer, a novel model based on a fused expert network for SOH estimation. By combining the strengths of state space models and recurrent neural networks, the model effectively handles the joint optimization of long-sequence dependency modeling and complex dynamic feature extraction. To improve temporal representation, ExpertMixer utilizes sampling time-based rotary position encoding (RoPE). It consists of two expert modules: a Mamba module designed to capture global degradation trends and an LSTM module focused on modeling local dynamic fluctuations. These are adaptively fused through a learnable gating mechanism that supports multi-scale feature integration. Experiments performed on the NASA PCoE dataset show that ExpertMixer achieves optimal performance on the NASA L subset, with an average MAE of 1.047 and RMSE of 1.603. It surpasses the traditional CNN BiGRU model, which had an MAE of 2.286, by 54.2%, and improves upon the advanced SambaMixer model, which had an MAE of 1.072, by 2.3%. Under low-temperature conditions using Battery 47, the model reduces the prediction error for nonlinear degradation to an MAE of 0.539, significantly exceeding all compared methods. Ablation studies verify the effectiveness of the dual-expert structure and fusion mechanism; removing the gating module results in an 18.7% decrease in performance. This research offers a new framework for lithium battery life prediction that demonstrates improved accuracy and generalization capability, suggesting potential practical value for intelligent energy storage management. Full article

The removal of the electrolyte solvents in an early-stage thermal drying step is crucial for safe and efficient recycling processes for end-of-life lithium-ion batteries. A comprehensive understanding of the governing influences on the solvent volatilization during the drying step enables optimized processes. The initial phase of this process is of particular interest because, due to the high spatial accessibility of the solvent, drying is determined by the mass transport in the surrounding gas phase, which can be precisely controlled through the process boundary conditions. In this study, the evaporation of representative binary and ternary electrolyte–solvent mixtures containing linear and cyclic organic carbonates is investigated under defined boundary conditions. The evaporation kinetics and selectivity are assessed by time-discrete measurement of the amount of solvent and its composition during the evaporation experiments. At the conditions applied, the vapor pressure of the solvents governs the evaporation selectivity, with the evaporation kinetics dictated by the mass transport of the solvent vapor in the gas phase. Hence, the evaporation of highly mobile but low volatile solvents, such as ethylene carbonate (EC), is the constraining aspect within this process. Moreover, molecular interactions within mixtures can further hinder the volatilization of EC. The developed simulation model describes the evaporation behavior with high accuracy and thus allows the prediction of minimum drying times. It establishes a solid foundation for designing and scaling the drying processes of end-of-life batteries, which involve complex material interactions. Full article

In this study, a PVA/graphene oxide (GO) hydrogel nanocomposite was synthesized as a adsorbent for Li⁺ removal from aqueous solutions. The composite was characterized by FTIR, XRD, and SEM/EDS to verify interfacial interactions and porous morphology. Batch adsorption experiments were performed to evaluate the effects of contact time, initial concentration, pH, and temperature. Kinetic analysis indicated that the pseudo-first-order model provided a better fit than the pseudo-second-order model under the tested conditions. Equilibrium data were best described by the Freundlich isotherm, suggesting adsorption on a heterogeneous surface. Thermodynamic results (ΔG° < 0) confirmed a spontaneous process, while the observed decrease in capacity with increasing temperature indicated an exothermic adsorption behavior. Overall, the PVA/GO hydrogel nanocomposite shows promise for lithium recovery from dilute aqueous streams. Full article

Hydrometallurgy is currently the mainstream industrial process for recovering valuable components (nickel, cobalt, manganese, lithium, etc.) from spent ternary lithium-ion battery cathode materials. During the crushing of lithium batteries, cathode materials, anode materials (graphite), and electrolytes become mixed. Consequently, fluoride ions inevitably enter the leaching solution during the hydrometallurgical recycling process, with concentrations as high as 100–300 mg/L. These fluoride ions not only adversely affect the quality of the recovered precursor products but also pose environmental risks. To address this issue, this study employs a synthesized lanthanum–zirconium (La@Zr) composite material, with a specific surface area of 67.41 m²/g and a pore size of 2–50 nm, which can reduce the fluoride ion concentration in the leaching solution to below 5 mg/L, significantly lower than the 20 mg/L or higher that is typically achieved with traditional calcium salt defluorination processes, without introducing new impurities. Under optimal adsorption conditions, the lanthanum–zirconium adsorbent exhibits a fluoride ion adsorption capacity of 193.4 mg/g in the leaching solution, surpassing that of many existing metal-based adsorbents. At the same time as the valuable metals, Li, Ni, and Co, are basically not adsorbed, the selective adsorption of fluoride ions can be achieved. Adsorption isotherm studies indicate that the adsorption process follows the Langmuir model, suggesting monolayer adsorption. The secondary adsorption process is primarily governed by chemical adsorption, and elevated temperatures facilitate the removal of fluoride ions. Kinetic studies demonstrate that the adsorption process is well described by the pseudo-second-order model. After desorption and regeneration with NaOH solution, the adsorbent still has a favorable fluoride removal performance, and the adsorption rate of fluoride ions can still reach 95% after four cycles of use. With its high capacity, rapid kinetics, and excellent selectivity, the adsorbent is highly promising for large-scale implementation. Full article

Near-complete (>99%) dissolution of lithium and cobalt was achieved by the leaching of black mass from spent (end-of-life) lithium-ion batteries (LiBs) using 4 M H₂SO₄ or HCl at 60 °C. Raising the temperature to 90 °C did not increase the overall extraction of lithium or cobalt, but it increased the rate of extraction. At 60 °C, 2 M H₂SO₄ or 2 M HCl performed similarly to the 4 M H₂SO₄/HCl solution, although extractions were lower using 1 M H₂SO₄ or HCl (~95% and 98%, respectively). High extractions were also observed by leaching in low pulp density (15 g/L) at 60 °C with 2 M CH₂ClCOOH. Leaching was much slower with hydrogen peroxide reductant concentrations below 0.5 mol/L, with cobalt extractions of 90–95% after 3 h. Pulp densities of up to 250 g/L were tested when leaching with 4 M H₂SO₄ or HCl, with the stoichiometric limit estimated for each test based on the metal content of the black mass. Extractions were consistently high, above 95% for Li/Ni/Mn/Cu with a pulp density of 150 g/L, dropping sharply above this point because of insufficient remaining acid in the solution in the later stages of leaching. The final component of the test work used leaching parameters identified in the previous experiments as producing the largest extractions, and just sulphuric acid. A seven-stage semi-continuous sulphuric acid leach at 60 °C of black mass from LiBs that had undergone an oxidising roast (2h in a tube furnace at 500 °C under flowing air) to remove binder material resulted in high (93%) extraction of cobalt and near total (98–100%) extractions of lithium, nickel, manganese, and copper. Higher cobalt extraction (>98%) was expected, but a refractory spinel-type cobalt oxide, Co₃O₄, was generated during the oxidising roast as a result of inefficient aeration, which reduced the extraction efficiency. Full article