Search Results (26)

In this work, iron–phosphorus-based composite biochar (FPBC) was prepared by modification with the leachate of spent LiFePO₄ batteries. The effects of solution pH, dosage, adsorption time, initial concentration, and temperature on the adsorption performance of FPBC were investigated by batch adsorption experiments with Pb(II) and Sb(III) as the target pollutants, and the adsorption mechanism was explored using SEM, BET, XPS, FTIR and XRD characterization. The results indicated that as the initial pH of the solution increased, the removal efficiency of FPBC for Pb(II) gradually increased, while the removal efficiency for Sb(III) remained largely unchanged. The removal of Pb(II) and Sb(III) by FPBC fitted the pseudo-second-order kinetic model and the three-step intraparticle diffusion model, indicating that their removal was primarily controlled by chemical adsorption. Isothermal adsorption studies revealed that FPBC adsorption of Pb(II) better fitted the Langmuir and D-R models, suggesting a monolayer-dominated adsorption process. In contrast, adsorption of Sb(III) fitted the Langmuir, Freundlich, and Temkin models, suggesting a combination of monolayer and multilayer adsorption characteristics. The maximum adsorption capacities of FPBC for Pb(II) and Sb(III) were 312.54 mg·g⁻¹ and 219.20 mg·g⁻¹ at 30 °C, which were approximately 12.85 and 3.37 times those of commercial corn stalk biochar (BC). Thermodynamic analysis confirmed that the removal of Pb(II) and Sb(III) by FPBC was a spontaneous and endothermic process. In addition, FPBC demonstrated strong selective adsorption of Pb(II) in the binary co-adsorption system of Pb(II) and Sb(III). Mechanism studies indicated that Pb(II) removal primarily occurred through co-precipitation, complexation, ion exchange, and electrostatic adsorption, while Sb(III) was mainly adsorbed by FPBC via redox reactions and complexation. Therefore, this work not only provides a low-cost, high-performance adsorbent for the remediation of water contaminated with Pb(II) and Sb(III), but also opens up new avenues for the resource recovery of the leachate of spent LiFePO₄ batteries. Full article

The recycling of spent lithium iron phosphate (LiFePO₄, LFP) batteries is receiving increasing attention as electric-vehicle deployment accelerates worldwide. Pyrometallurgical reduction offers a viable route for large-scale recovery of iron-rich products from spent LFP batteries; however, the resulting Fe-based alloys often retain residual copper (Cu), which deteriorates alloy quality and constrains downstream utilization and refining. In this study, a sulfidation–slag refining process was developed to selectively remove Cu from an Fe–P–Cu alloy produced by dry reduction of spent LFP batteries. FeS was employed as a sulfidizing agent to promote preferential conversion of Cu into sulfide phases, while fayalite (Fe₂SiO₄) slag was introduced to enhance phase separation between metallic and sulfide/slag phases. Thermodynamic calculations coupled with high-temperature experiments were conducted at 1400–1600 °C under various Cu:FeS ratios to identify operating conditions that maximize Cu removal while minimizing Fe loss. The results indicate that Cu is selectively transferred from the metallic phase to Cu–Fe–S sulfide phases, whereas Fe remains predominantly in the metal phase. Under the optimal condition (1400 °C, Cu:FeS = 2:1), the refined metal reached an Fe content of 90.80 wt.%, achieving an Fe recovery of 87.42% and a Cu removal efficiency of 81.13%. The proposed approach provides a practical stepwise refining strategy for upgrading Fe-rich secondary resources recovered from spent LFP batteries and facilitates subsequent impurity-control processes. Full article

Traditional lithium-ion battery recycling relies mainly on pyrolysis or chemical leaching to separate current collectors from electrode materials, inevitably resulting in secondary pollution. In contrast, eddy current separation (ECS) applied to crushed lithium-ion battery residues can substantially reduce the introduction of contaminants while minimizing material losses. However, the heterogeneous composition and diverse surface characteristics of crushed battery products, together with the conductivity degradation of electrode materials after long-term use, make conventional empirical particle–trajectory correlations inadequate for accurate optimization of ECS operating parameters. In addition, the coupling between process parameters and the resultant forces acting on conductive particles, as well as the associated separation trajectories, remain insufficiently understood, which severely limits process controllability. A force–trajectory model was therefore developed for spent current collectors and conductivity-degraded LiFePO₄ to describe their particle dynamics in an alternating magnetic field. The results demonstrate that the trajectory of LiFePO₄ is very similar to that of non-conductive materials, thereby facilitating its effective separation from metallic components in battery scrap. Eddy current separation experiments further confirm the accuracy of the model predictions with respect to separation trajectories and the influence of key process parameters. On this basis, optimization of the operating parameters increased the separation efficiency of the cathode material to above 95.1%. The clarified ECS mechanism for current collectors and electrode materials provides new insights into the mechanical pre-sorting and mechanistic understanding of lithium-ion battery fragments, thereby contributing to reductions in contaminant introduction during battery material recycling. Full article

The rapid expansion of lithium-ion battery (LIB) applications and the imminent surge in end-of-life batteries have intensified the demand for efficient, scalable recycling technologies. Physical separation of cathode and anode materials is a crucial pretreatment step that enables high-value metal recovery and direct material regeneration. This review critically examines recent advances in three major physical separation technologies—magnetic separation, gravity separation, and flotation—for processing spent LIB electrodes. Rather than offering a descriptive summary, the review systematically analyzes separation mechanisms, key controlling parameters, and pretreatment strategies across representative cathode chemistries, including LiFePO₄ (LFP), LiCoO₂ (LCO), and Ni–Co–Mn (NCM) systems. Particular emphasis is placed on emerging flotation-enhancement strategies, such as nanobubble-assisted and ultrasonic-enhanced flotation, and their underlying mechanistic roles in improving selectivity and recovery. Comparative evaluation indicates that magnetic separation has reached industrial maturity for LFP–graphite systems but remains chemistry-specific. Gravity separation is effective for coarse particles and centrifugal-assisted graphite recovery yet shows limited selectivity for fine particles. Flotation has become the dominant research focus for complex, fine-particle separations due to its tunable surface chemistry. Despite significant laboratory progress, challenges remain, including incomplete binder removal, limited understanding of electrode surface reconstruction during pretreatment, fine-particle entrainment, and the gap between bench-scale research and industrial implementation. Future research priorities include green reagent development, intelligent separation control, and integration with direct regeneration routes to advance closed-loop LIB recycling towards sustainable development. Full article

With the increasing deployment of lithium iron phosphate (LiFePO₄) batteries in electric vehicles and energy storage systems, the recycling of these materials has become an urgent necessity. Specifically, the reclamation of lithium iron phosphate cathode materials presents a significant challenge in the recycling process. In this study, we proposed an efficient low-temperature hydrothermal direct regeneration method aimed at repairing lithium vacancies and Fe/Li inversion defects in spent lithium iron phosphate resulting from prolonged cycling. By using this method, spent lithium iron phosphate was successfully regenerated through a hydrothermal process conducted at 80 °C for 6 h, utilizing hydrazine hydrate (N₂H₄·H₂O) as a potent reducing agent and lithium hydroxide (LiOH·H₂O) as the lithium source. X-ray diffraction (XRD) analysis, coupled with Rietveld refinement, revealed a substantial reduction in the concentration of Fe/Li anti-site defects in the spent material, decreasing from 8.8% to 3.3% following regeneration. Consequently, the electrochemical performance was significantly restored. The initial specific discharge capacity increased from 118.0 mAh·g⁻¹ to 150.3 mAh·g⁻¹, and the capacity retention after 100 cycles (at 1 C) improved from 67.5% to 90.7%. The hydrothermal regeneration process introduced in this work effectively repairs the material structure and restores the active valence state of iron, thereby significantly enhancing lithium-ion diffusion and electron transport capabilities. This approach constitutes a technically viable solution for the efficient, environmentally friendly, and cost-effective recycling of spent lithium-ion batteries. Full article

In this study, spent LiFePO₄ (LFP) cathode materials were recycled and transformed into amorphous FePO₄ (a-FePO₄) via a leaching–precipitation method for further use as a high-performance cathode material in lithium-ion batteries. To enhance its electrochemical performance, a-FePO4 was composited with graphene oxide (GO) and subsequently reduced at different temperatures (250–450 °C) under N₂ atmosphere to obtain a series of a-FePO₄/rGO composites. Among them, the a-FePO₄-rGO-1 (reduced at 250 °C) exhibited the most superior performance, delivering a specific high discharge capacity of 117 mAh·g⁻¹ after 100 cycles at 1 C and an excellent rate capability of 98 mAh·g⁻¹ even at 10 C. Electrochemical impedance spectroscopy revealed that this composite possessed the lowest charge transfer resistance and most efficient Li⁺ diffusion kinetics. This study demonstrates that moderate-temperature thermal reduction is a critical strategy for optimizing the conductive network of a-FePO₄-rGO composites, thereby significantly improving the electrochemical properties of recycled FePO₄-based cathode materials. Full article

The sustainable recycling of valuable metals from spent lithium-ion batteries (LIBs) is critical for resource conservation and environmental protection but remains challenging due to the complex coexistence of target and impurity metals. This study systematically investigates the selective leaching behaviors of metals (Co, Li, Cu, Fe, Al) in phosphoric acid media, revealing that lithium could be preferentially extracted in mild acidic conditions (0.8 mol/L H₃PO₄), while complete dissolution of both Li and Co was achieved in concentrated acid (2.0 mol/L H₃PO₄). Kinetic analysis demonstrated that metal leaching followed a chemically controlled mechanism, with distinct extraction sequences: Li > Cu~Co > Fe > Al in dilute acid and Cu > Al~Li > Fe > Co in concentrated acid. Furthermore, we developed a closed-loop process wherein oxalic acid simultaneously precipitates Co/Li while regenerating H₃PO₄, enabling acid reuse with minimal efficiency loss during cyclic leaching. These findings establish a single-step phosphoric acid leaching strategy for selective metal recovery, governed by tunable acid concentration and reaction kinetics, offering a sustainable pathway for LIBs recycling. Full article

Next-generation recycling technologies must be urgently innovated to tackle huge volumes of spent batteries, photovoltaic panels or printed circuit boards (WPCBs). Current e-waste recycling industrial technology is dominated by traditional recycling technologies. Herein, ionic liquids (ILs), deep eutectic solvents (DESs) and promising oxidizing additives that can overcome some traditional recycling methods of metal ions from e-waste, used in our works from last year, are presented. The unique chemical environments of ILs and DESs, with the application of low-temperature extraction procedures, are important environmental aspects known as “Green Methods”. A closed-loop system for recycling zinc and manganese from the “black mass” (BM) of waste, Zn-MnO₂ batteries, is presented. The leaching process achieves a high efficiency and distribution ratio using the composition of two solvents (Cyanex 272 + diethyl phosphite (DPh)) for Zn(II) extraction. High extraction efficiency with 100% zinc and manganese recovery is also achieved using DESs (cholinum chloride/lactic acid, 1:2, DES 1, and cholinum chloride/malonic acid, 1:1, DES 2). New, greener recycling approaches to metal extraction from the BM of spent Li-ion batteries are presented with ILs ([N_8,8,8,1][Cl], (Aliquat 336), [P_6,6,6,14][Cl], [P_6,6,6,14][SCN] and [Benzet][TCM]) eight DESs, Cyanex 272 and D2EHPA. A high extraction efficiency of Li(I) (41–92 wt%) and Ni(II) (37–52 wt%) using (Cyanex 272 + DPh) is obtained. The recovery of Ni(II) and Cd(II) from the BM of spent Ni-Cd batteries is also demonstrated. The extraction efficiency of DES 1 and DES 2, contrary to ILs ([P_6,6,6,14][Cl] and [P_6,6,6,14][SCN]), is at the level of 30 wt% for Ni(II) and 100 wt% for Cd(II). In this mini-review, the option to use ILs, DESs and Cyanex 272 for the recovery of valuable metals from end-of-life WPCBs is presented. Next-generation recycling technologies, in contrast to the extraction of metals from acidic leachate preceded by thermal pre-treatment or from solid material only after thermal pre-treatment, have been developed with ILs and DESs using the ABS method, as well as Cyanex 272 (only after the thermal pre-treatment of WPCBs), with a process efficiency of 60–100 wt%. In this process, four new ILs are used: didecyldimethylammonium propionate, [N_10,10,1,1][C₂H₅COO], didecylmethylammonium hydrogen sulphate, [N_10,10,1,H][HSO₄], didecyldimethylammonium dihydrogen phosphate, [N_10,10,1,1][H₂PO₄], and tetrabutylphosphonium dihydrogen phosphate, [P_4,4,4,4][H₂PO₄]. The extraction of Cu(II), Ag(I) and other metals such as Al(III), Fe(II) and Zn(II) from solid WPCBs is demonstrated. Various additives are used during the extraction processes. The Analyst 800 atomic absorption spectrometer (FAAS) is used for the determination of metal content in the solid BM. The ICP-OES method is used for metal analysis. The obtained results describe the possible application of ILs and DESs as environmental media for upcycling spent electronic wastes. Full article

The rapid growth of lithium iron phosphate (LiFePO₄, LFP)-based lithium-ion batteries in energy storage raises urgent challenges for resource recovery and environmental protection. In this study, we propose a novel method for rapid and selective lithium extraction and the resynthesis of cathodes from spent LFP batteries, aiming to achieve an economically feasible and efficient recycling process. In this process, a selective leaching H₂SO₄-H₂O₂ system is employed to rapidly and selectively extract lithium, achieving a leaching efficiency of 98.72% within just 10 min. Through an exploration of the precipitation conditions of the lithium-containing solution, high-purity Li₂CO₃ is successfully obtained. The recovered FePO₄ and Li₂CO₃ are then used to resynthesize LFP cathode materials through a carbon-thermal reduction method. A preliminary economic analysis reveals that the disposal cost of spent LFP batteries is approximately USD 2.63 per kilogram, while the value of regenerated LFP reaches USD 4.46, highlighting the economic advantages of this process. Furthermore, with an acid-to-lithium molar ratio of only 0.57—just slightly above the stoichiometric 0.5—the process requires minimal acid usage, offering clear environmental benefits. Overall, this work presents a green, efficient, and economically viable strategy for recycling spent LFP batteries, showcasing strong potential for industrial application and contributing significantly to the development of a circular lithium battery economy. Full article

LiFePO₄ (LFP) batteries are among the earliest commercialized and most discarded lithium-ion batteries. Although existing recovery technologies focus on the conversion of LiFePO₄ to Li₂CO₃, challenges associated with achieving near-full recovery and high-value products remain. This study proposes a strategy for the conversion of spent LiFePO₄ to LiF by mechanical chlorination coupled with a fluorination reaction. The optimum conditions were determined to be a ball-to-powder ratio (BPR) = 15, NH₄Cl:LFP = 3, H₂O₂ = 2.0 mL, rotation speed = 600 rpm, and grinding time = 12 h. Results showed that 97.14% Li was converted into LiCl by H₂O₂–NH₄Cl mechanical chlorination. When chlorinated intermediates were immersed in water, FePO₄ could be harvested, and 96.79% Li could be recovered as LiF with a purity of 99.50% after adding NH₄F. When Cl-functionalized renewable resin was used to exchange 99.89% F⁻, 0.63 g NH₄Cl per litre of LiF conversion residual liquid was derived. The favourable results were attributed to the ¹O₂ generated by H₂O₂, which had a strong electron affinity to break Li–O bonds and provided superior conditions for the combination of Li and Cl. During fluorination, the formation of LiF reduced the ion concentration, and the entropy decreased, contributing to the spontaneous reaction. Therefore, the proposed method paves the way for near-full recovery and high-value products of spent LiFePO₄. Full article

The effective recovery of valuable materials from spent LiFePO₄ batteries is crucial for resource sustainability and environmental protection. This study investigates the recovery of phosphorus iron slag from waste LiFePO₄ batteries, focusing on dissolution and impurity removal processes to produce battery-grade iron phosphate. Using high-temperature-activated dissolution, followed by precipitation/dissolution for impurity removal, we optimize conditions to ensure high recovery rates (up to 98.8% for FePO₄ under optimized conditions) and product purity. Our findings demonstrate that the proposed method effectively transforms waste slag into valuable iron phosphate, significantly reducing raw material costs and contributing to sustainable battery recycling practices. The regenerated LiFePO₄ cathode exhibits excellent electrochemical performance, achieving a discharge capacity of 160.7 mAh g⁻¹ at 0.1 C, which meets market standard levels. This research provides a solid foundation for enhancing resource utilization and advancing circular economy principles in the battery industry. Full article

This study investigates advanced strategies for r regenerating and recycling lithium iron phosphate (LiFePO₄, LFP) materials from spent lithium-ion batteries. Recovery techniques are categorized into direct regeneration, which restores positive electrode materials with high electrochemical performance, and recycling, which produces intermediate compounds such as lithium carbonate and iron phosphate. Additionally, resynthesis methods are explored to convert recovered precursors into high-quality LFP materials, ensuring their reuse in battery production. Innovative approaches, including carbothermic reduction, doping, and hydrothermal resynthesis, are highlighted for their ability to enhance material properties, improve energy efficiency, and maintain the olivine structure of LFP. Key advancements include the use of eco-friendly reagents, automation, and optimization strategies to reduce environmental impacts and costs. Regenerated and resynthesized positive electrodes demonstrated performance metrics comparable to or exceeding commercial LFP, showcasing their potential for widespread application. This work underscores the importance of closed-loop recycling systems and identifies pathways for scaling, improving economic feasibility, and minimizing the ecological footprint of the lithium-ion battery lifecycle. Full article

The growing adoption of lithium iron phosphate (LiFePO₄) batteries in electric vehicles (EVs) and renewable energy systems has intensified the need for sustainable management at the end of their life cycle. This study introduces an innovative method for recycling lithium from spent LiFePO₄ batteries and repurposing the recovered lithium carbonate (Li₂CO₃) as a carbon dioxide (CO₂) absorber. The recycling process involves dismantling battery packs, separating active materials, and chemically treating the cathode to extract lithium ions, which produces Li₂CO₃. The efficiency of lithium recovery is influenced by factors such as leaching temperature, acid concentration, and reaction time. Once recovered, Li₂CO₃ can be utilized for CO₂ capture in hydrogen purification processes, reacting with CO₂ to form lithium bicarbonate (LiHCO₃). This reaction, which is highly effective in aqueous solutions, can be applied in industrial settings to mitigate greenhouse gas emissions. The LiHCO₃ can then be thermally decomposed to regenerate Li₂CO₃, creating a cyclic and sustainable use of the material. This dual-purpose process not only addresses the environmental impact of LiFePO₄ battery disposal but also contributes to CO₂ reduction, aligning with global climate goals. Utilizing recycled Li₂CO₃ decreases the demand for virgin lithium extraction, supporting a circular economy. Furthermore, integrating Li₂CO₃-based CO₂ capture systems into existing industrial infrastructure provides a scalable and cost-effective solution for lowering carbon footprints while securing a continuous supply of lithium for future battery production. Future research should focus on optimizing lithium recovery methods, improving the efficiency of CO₂ capture, and exploring synergies with other waste management and carbon capture technologies. This comprehensive strategy underscores the potential of lithium recycling to address both resource conservation and environmental protection challenges. Full article

The rapid growth of electronic devices, electric vehicles, and mobile energy storage has produced large quantities of spent batteries, leading to significant environmental issues and a shortage of lithium resources. Recycling spent batteries has become urgent to protect the environment. The key to treating spent lithium-ion batteries is to implement green and efficient regeneration. This study proposes a recycling method for the direct regeneration of spent lithium iron phosphate (LFP) batteries using hydrothermal reduction. Ascorbic acid (AA) was used as a low-cost and environmentally friendly reductant to reduce Fe³⁺ in spent LiFePO₄. We also investigated the role of AA in the hydrothermal process and its effects on the electrochemical properties of the regenerated LiFePO₄ cathode material (AA-SR-LFP). The results showed that the hydrothermal reduction direct regeneration method successfully produced AA-SR-LFP with good crystallinity and electrochemical properties. AA-SR-LFP exhibited excellent electrochemical properties, with an initial discharge specific capacity of 144.4 mAh g⁻¹ at 1 C and a capacity retention rate of 98.6% after 100 cycles. In summary, the hydrothermal reduction direct regeneration method effectively repairs the defects in the chemical composition and crystal structure of spent LiFePO₄. It can be regarded as a green and effective regeneration approach for spent LiFePO₄ cathode materials. Full article

As of 2035, the European Union has ratified the obligation to register only zero-emission cars, including ultra-low-emission vehicles (ULEVs). In this context, electric mobility fits in, which, however, presents the critical issue of the over-exploitation of critical raw materials (CRMs). An interesting solution to reduce this burden could be the so-called second life, in which batteries that are no longer able to guarantee high performance in vehicles are used for other applications that do not require high performance, such as so-called stationary systems, effectively avoiding new over-exploitation of resources. In this study, therefore, the environmental impacts of second-life lithium iron phosphate (LiFePO₄) batteries are verified using a life cycle perspective, taking a second life project as a case study. The results show how, through the second life, GWP could be reduced by −5.06 × 10¹ kg CO₂ eq/kWh, TEC by −3.79 × 10⁰ kg 1.4 DCB eq/kWh, HNCT by −3.46 × 10⁰ kg 1.4 DCB eq/kWh, −3.88 × 10⁰ m²a crop eq/kWh, and −1.12 × 10¹ kg oil eq/kWh. It is further shown how second life is potentially preferable to other forms of recycling, such as hydrometallurgical and pyrometallurgical recycling, as it shows lower environmental impacts in all impact categories, with environmental benefits of, for example, −1.19 × 10¹ kg CO₂ eq/kWh (compared to hydrometallurgical recycling) and −1.50 × 10¹ kg CO₂ eq/kWh (pyrometallurgical recycling), −3.33 × 10² kg 1.4 DCB eq/kWh (hydrometallurgical), and −3.26 × 10² kg 1.4 DCB eq/kWh (pyrometallurgical), or −3.71 × 10⁰ kg oil eq/kWh (hydrometallurgical) and −4.56 × 10⁰ kg oil eq/kWh (pyrometallurgical). By extending the service life of spent batteries, it may therefore be possible to extract additional value while minimizing emissions and the over-exploitation of resources. Full article