Process Development for the Recycle of Spent Lithium Ion Batteries by Chemical Precipitation

Comprehensive review and comparison on pretreatment of spent lithium-ion battery

Pretreatment, the initial step in recycling spent lithium-ion batteries (LIBs), efficiently separates cathode and anode materials to facilitate key element recovery. Despite brief introductions in existing research, a comprehensive evaluation and comparison of processing methods is lacking. This study reviews 346 references on LIBs recycling, analyzing pretreatment stages, treatment conditions, and method effects. Our analysis highlights insufficient attention to discharge voltage safety and environmental impact. Mechanical disassembly, while suitable for industrial production, overlooks electrolyte recovery and complicates LIBs separation. High temperature pyrolysis flotation offers efficient separation of mixed electrode materials, enhancing mineral recovery. We propose four primary pretreatment processes: discharge, electrolyte recovery, crushing and separation, and electrode material recovery, offering simplified, efficient, green, low-cost, and high-purity raw materials for subsequent recovery processes.

Ferrioxalate photolysis-assisted green recovery of valuable resources from spent lithium iron phosphate batteries

Recovering valuable resources from spent cathodes while minimizing secondary waste generation is emerging as an important objective for the future recycling of spent lithium-ion batteries, including lithium iron phosphate (LFP) batteries. This study proposes the use of oxalic acid leaching followed by ferrioxalate photolysis to separate and recover cathode active material elements from spent LFP batteries. The cathode active material can be rapidly dissolved at room temperature using appropriate quantities of oxalic acid and hydrogen peroxide, as determined through thermodynamic calculations. The dissolved ferrioxalate complex ion (Fe(C2O4)33-) is selectively precipitated through subsequent photolysis at room temperature. Depending on the initial concentration, the decomposition ratio can exceed 95 % within 1-4 h. Molecular mechanism analysis reveals that the decomposition of the Fe(C2O4)33- complex ion into water-insoluble FeC2O4·2H2O results in the precipitation of iron and the separation of metal elements. Lithium can be recovered as dihydrogen phosphates through filtration and water evaporation. No additional precipitant is needed and no other side products are generated during the process. Oxalic acid leaching followed by photolysis offers an environmentally friendly and efficient method for metal recovery from spent LFP cathodes. The photochemical process is a promising approach for reducing secondary waste generation in battery recycling.

Toward Direct Regeneration of Spent Lithium-Ion Batteries: A Next-Generation Recycling Method

The popularity of portable electronic devices and electric vehicles has led to the drastically increasing consumption of lithium-ion batteries recently, raising concerns about the disposal and recycling of spent lithium-ion batteries. However, the recycling rate of lithium-ion batteries worldwide at present is extremely low. Many factors limit the promotion of the battery recycling rate: outdated recycling technology is the most critical one. Existing metallurgy-based recycling methods rely on continuous decomposition and extraction steps with high-temperature roasting/acid leaching processes and many chemical reagents. These methods are tedious with worse economic feasibility, and the recycling products are mostly alloys or salts, which can only be used as precursors. To simplify the process and improve the economic benefits, novel recycling methods are in urgent demand, and direct recycling/regeneration is therefore proposed as a next-generation method. Herein, a comprehensive review of the origin, current status, and prospect of direct recycling methods is provided. We have systematically analyzed current recycling methods and summarized their limitations, pointing out the necessity of developing direct recycling methods. A detailed analysis for discussions of the advantages, limitations, and obstacles is conducted. Guidance for future direct recycling methods toward large-scale industrialization as well as green and efficient recycling systems is also provided.

A comprehensive review of emerging technologies for recycling spent lithium-ion batteries

Along with the increasing demand for lithium-ion batteries (LIB), the need for recycling major components such as graphite and different critical materials contained in LIB is also reaching a peak in the research community. Several authors review the different LIB recycling methodologies, including pyro- and hydrometallurgy processes. However, the characteristics, main stages, and achievements of LIB emerging recycling are still missing. This study reviews the diverse emerging approaches for recycling critical materials from spent LIB in the last five years. A classification for emerging recycling technologies is provided, including terms like development stage and eco-friendly status. The main stages of recycling LIB are opening, phase separation, and materials recovery. Among the emerging proposals with the highest industrialization potential are direct recycling techniques due to low costs and simple procedures. Concerning phase separation, froth flotation and ultrasound-assisted methods are discussed. The former divides black mass into pure anodic and cathodic materials, while ultrasonication is employed to physically detach active materials from foils or enhance binder degradation. As to materials recovery, several recent approaches show high recovery efficiency for different elements, mainly in leaching. The use of new organic acids, deep eutectic acids, and some salts are worth noting as leaching agents due to their low environmental impact. In addition, leaching methods assisted by ultrasound and microwave irradiation increase valuable metal recovery, reducing time consumption and the number of leaching reactants. As a part of the hydrometallurgy process, metallic ion purification is performed by solvent extraction and ion exchange, while selective precipitation can be achieved by specific chemical agents or electrochemical processes.

Recycling of valuable metals from spent lithium-ion batteries by self-supplied reductant roasting

The massive spent lithium-ion batteries (LIBs) need to be recycled due to their increasing decommission in recent years. This paper aims to propose an effective process that uses self-supplied reductant roasting and acid leaching to recover Lithium, Nickle, Cobalt and Manganese from spent LIBs. In the absence of external carbon resources, the waste membrane from spent LIBs was used as the reductant in the self-supplied reductant roasting. A thermodynamic analysis was conducted to judge the possible reduction reaction between the cathode material and waste membrane. Then, the effects of roasting temperature, roasting time and membrane dosage on the crystal structure and phase transformation of roasting products were investigated and optimized. After the roasting process, the valence state of metals in the cathode material decreased and the structure became loose and porous. Moreover, the layer structure of the cathode material was transformed into groups of Li₂CO₃, Ni, Co, NiO, CoO and MnO. Further, the reduction effect of cathode powders under each roasting condition was verified under the same leaching conditions. After leaching for 30 min, the leaching efficiencies of Li, Ni, Co and Mn were over 99% under the optimum roasting conditions. Finally, economic assessments proved that the proposed process is profitable. The whole process demonstrates an effective and positive way for recycling spent LIBs and making full use of their waste membrane, which promotes resource recovery and environmental protection.

The Use of Redox Mediators in Electrocatalysis and Electrosynthesis

Electrocatalysis and electrosynthesis, which convert the electrical energy and store them in the chemical forms, have been considered as promising technologies to utilize green renewable energy sources. Most of the studies focused on developing novel active molecules or advanced electrodes to improve the performance. However, the direct acquisition and electron transferring will be limited by the intrinsic characters of the electrodes. The introduce of redox mediators, which are served as the intermediate electron carriers or reservoirs without changing the final products, provide a unique approach to accelerate the electrochemical performance of these energy conversions. This review provides an overview of the recent development of electrocatalysis and electrosynthesis by using redox mediators, and provides a comprehensive discussion toward focusing on the principles and construction of these systems.

Progress, Key Issues, and Future Prospects for Li-Ion Battery Recycling

The overuse and exploitation of fossil fuels has triggered the energy crisis and caused tremendous issues for the society. Lithium-ion batteries (LIBs), as one of the most important renewable energy storage technologies, have experienced booming progress, especially with the drastic growth of electric vehicles. To avoid massive mineral mining and the opening of new mines, battery recycling to extract valuable species from spent LIBs is essential for the development of renewable energy. Therefore, LIBs recycling needs to be widely promoted/applied and the advanced recycling technology with low energy consumption, low emission, and green reagents needs to be highlighted. In this review, the necessity for battery recycling is first discussed from several different aspects. Second, the various LIBs recycling technologies that are currently used, such as pyrometallurgical and hydrometallurgical methods, are summarized and evaluated. Then, based on the challenges of the above recycling methods, the authors look further forward to some of the cutting-edge recycling technologies, such as direct repair and regeneration. In addition, the authors also discuss the prospects of selected recycling strategies for next-generation LIBs such as solid-state Li-metal batteries. Finally, overall conclusions and future perspectives for the sustainability of energy storage devices are presented in the last chapter.

Regeneration and usage of commercial activated carbon from the waste electrodes for the application of supercapacitors

Currently, efficient and cost-effective recycling of waste capacitors is a pressing issue. In this study, the recovery of electrode powder from waste supercapacitors and enabling the reuse of the prepared samples are reported. The recovered powder is directly activated by mixing it with KOH using chemical activation to regenerate the waste-activated carbon. The regenerated activated carbon's specific surface area could be restored to a level similar to that of the original commercial powder, reaching 1803.15 m²/g. The regenerated activated carbon has a high proportion of microporous, which played a crucial role in its electrochemical performance. The samples' capacity in the organic system reached 125.96 F/g at 0.2 A/g and 111.77 F/g at 20 A/g, with a retention rate of 88.74%. Furthermore, the capacitance was maintained at 91.18% after 10,000 cycles, showing good cycling performance. Additionally, the supercapacitor assembled from the regenerated activated carbon delivered a high energy density of 31.83 Wh/kg and a power density of 269.76 W/kg, indicating great application potential. Overall, this study offers a useful and low-cost approach for recycling activated carbon from waste electrodes, which would be possible for supercapacitors recycling.

Recycling of cathode material from spent lithium-ion batteries: Challenges and future perspectives

The intrinsic advancement of lithium-ion batteries (LIBs) for application in electric vehicles (EVs), portable electronic devices, and energy-storage devices has led to an increase in the number of spent LIBs. Spent LIBs contain hazardous metals (such as Li, Co, Ni, and Mn), toxic and corrosive electrolytes, metal casting, and polymer binders that pose a serious threat to the environment and human health. Additionally, spent LIBs may serve as an economic source for transition metals, which could be applied to redesigning under a closed-circuit recycling process. Thus, the development of environmentally benign, low cost, and efficient processes for recycling of LIBs for a sustainable future has attracted worldwide attention. Therefore, herein, we introduce the concept of LIBs and review state-of-art technologies for metal recycling processes. Moreover, we emphasize on LIB pretreatment approaches, metal extraction, and pyrometallurgical, hydrometallurgical, and biometallurgical approaches. Direct recycling technologies combined with the profitable and sustainable cathode healing technology have significant potential for the recycling of LIBs without decomposition into substituent elements or precipitation; hence, these technologies can be industrially adopted for EV batteries. Finally, commercial technological developments, existing challenges, and suggestions are presented for the development of effective, environmentally friendly recycling technology for the future.

A Novel Low-Temperature Fluorination Roasting Mechanism Investigation of Regenerated Spent Anode Graphite via TG-IR Analysis and Kinetic Modeling

Spent anode graphite, a hazardous solid waste discarded from the recovery of spent lithium-ion batteries (LIBs), had created social and environmental issues but has been scarcely investigated. Thus, a feasible, environmentally friendly, and economical process of low-temperature fluorination roasting and water leaching technology was proposed to regenerate spent graphite anodes. The results showed that the physical and chemical properties of regenerated graphite with a purity of 99.98% reached the graphite anode standard of LIBs and exhibited a stable specific capacity (340.9 mAh/g), capacity retention (68.92% after 470th cycles), and high initial Coulombic efficiency (92.13%), much better than that of waste carbon residue and similar to that of commercial graphite. Then the reaction mechanism and kinetic modeling of fluorination roasting of spent anode material was mainly explored by differential thermogravimetry and nonisothermal analysis methods. The results showed that the complexation and phase-transformation process of non-carbon valuable components in spent anode graphite occurred through three consecutive reactions in the 80-211 °C temperature intervals. The reaction mechanism of the whole process can be kinetically characterized by three successive reactions: third-order chemical reaction, Z-L-T eq, and second-order chemical reaction. Moreover, the thermodynamic functions of the fluorination roasting were calculated by the activated complex theory (transition state), which indicated the process was nonspontaneous. The mechanistic information was in good agreement with thermogravimetric-infrared spectroscopy (TG-IR), electron probe microanalysis, scanning electron microscopy, energy-dispersive spectrometry, and simulation experiments results.

Literature Review, Recycling of Lithium-Ion Batteries from Electric Vehicles, Part I: Recycling Technology

During recent years, emissions reduction has been tightened worldwide. Therefore, there is an increasing demand for electric vehicles (EVs) that can meet emission requirements. The growing number of new EVs increases the consumption of raw materials during production. Simultaneously, the number of used EVs and subsequently retired lithium-ion batteries (LIBs) that need to be disposed of is also increasing. According to the current approaches, the recycling process technology appears to be one of the most promising solutions for the End-of-Life (EOL) LIBs—recycling and reusing of waste materials would reduce raw materials production and environmental burden. According to this performed literature review, 263 publications about “Recycling of Lithium-ion Batteries from Electric Vehicles” were classified into five sections: Recycling Processes, Battery Composition, Environmental Impact, Economic Evaluation, and Recycling & Rest. The whole work reviews the current-state of publications dedicated to recycling LIBs from EVs in the techno-environmental-economic summary. This paper covers the first part of the review work; it is devoted to the recycling technology processes and points out the main study fields in recycling that were found during this work.

Cobalt Recovery from Li-Ion Battery Recycling: A Critical Review

The increasing demand for Li-ion batteries for electric vehicles sheds light upon the Co supply chain. The metal is crucial to the cathode of these batteries, and the leading global producer is the D.R. Congo (70%). For this reason, it is considered critical/strategic due to the risk of interruption of supply in the short and medium term. Due to the increasing consumption for the transportation market, the batteries might be considered a secondary source of Co. The outstanding amount of spent batteries makes them to a core of urban mining warranting special attention. Greener technologies for Co recovery are necessary to achieve sustainable development. As a result of these sourcing challenges, this study is devoted to reviewing the techniques for Co recovery, such as acid leaching (inorganic and organic), separation (solvent extraction, ion exchange resins, and precipitation), and emerging technologies—ionic liquids, deep eutectic solvent, supercritical fluids, nanotechnology, and biohydrometallurgy. A dearth of research in emerging technologies for Co recovery from Li-ion batteries is discussed throughout the manuscript within a broader overview. The study is strictly connected to the Sustainability Development Goals (SDG) number 7, 8, 9, and 12.

Lithium recovery from effluent of spent lithium battery recycling process using solvent extraction

A novel process of lithium recovery from effluent of spent lithium batteries recycling by solvent extraction was proposed. The β-diketone extraction system used in the experiment was composed of benzoyltrifluoroacetone (HBTA), trioctylphosphine oxide (TOPO) and kerosene. The effective parameters such as solution pH value, saponification degree, initial lithium concentration and phase ratio were evaluated by experiments. More than 90% of lithium could be extracted by saponified organic phase through three-stage countercurrent extraction. The loaded organic phase was first eluted by dilute HCl solution to remove nontarget sodium, and then stripped by 6 mol/L HCl at a large phase ratio to obtain lithium-rich solution with 4.322 mol/L lithium. The lithium-rich solution from the process could be used to prepare lithium carbonate or lithium chloride. The stripped organic phase can be recycled and no crud or emulsification was observed during the process. The extraction mechanism of HBTA-TOPO was investigated via FT-IR spectroscopy, and the results indicated the two extractants showed strong synergistic effect. The thermodynamic study revealed lithium extraction is an exothermic process, which meant lower temperature promotes extraction of lithium. This work provided a novel approach to recover lithium from effluent of spent lithium battery recycling.

Recycling Chain for Spent Lithium-Ion Batteries

The recycling of spent lithium-ion batteries (LIB) is becoming increasingly important with regard to environmental, economic, geostrategic, and health aspects due to the increasing amount of LIB produced, introduced into the market, and being spent in the following years. The recycling itself becomes a challenge to face on one hand the special aspects of LIB-technology and on the other hand to reply to the idea of circular economy. In this paper, we analyze the different recycling concepts for spent LIBs and categorize them according to state-of-the-art schemes of waste treatment technology. Therefore, we structure the different processes into process stages and unit processes. Several recycling technologies are treating spent lithium-ion batteries worldwide focusing on one or several process stages or unit processes.

Rapid dissolution and recovery of Li and Co from spent LiCoO2 using mild organic acids under microwave irradiation

This study is aimed to recover the valuable metal ions from cathode materials of spent Li‒ion batteries (LIBs). Rapid microwave‒assisted dissolution process is investigated here to recover Li and Co from LiCoO₂ of spent LIBs. In the conventional method, about 6 h is required to extract about 90% of Li and Co using a mixture of citric acid (CA) and ascorbic acid (AA) at 80 °C. On the other hand, more than 85% of Li and Co was obtained in about 25 min by microwave (180 W)‒assisted dissolution. The dissolved Co and Li ions were precipitated, selectively: Li as LiHC₂O₄ H₂O or Li₂CO₃ and Co as CoC₂O₄ 2H₂O or Co‒citrate/ascorbate. The Co₃O₄ was formed on heating the Co precipitate at 600 °C for 2 h. It is important to note that LiCoO₂ was re‒synthesized here by thermal decomposition of CoC₂O₄ 2H₂O and LiHC₂O₄ H₂O at 750 °C for about 24 h. Thus, the microwave‒assisted hydrometallurgical method is found to be simple and rapid to recover Li and Co from spent LIBs.

Hydrothermal preparation and performance of LiFePO4 by using Li3PO4 recovered from spent cathode scraps as Li source

A novel process recycling Li from the spent LiFePO₄ cathode material has been put forward. The new LiFePO₄ sample is synthesized through hydrothermal reaction by using recovered Li₃PO₄ as Li source and FeSO₄·7H₂O as Fe source. The morphologies, structure and physicochemical properties of the re-synthesized LiFePO₄ cathode material were characterized by Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurement. The results showed that the morphology and particle size of re-synthesized LiFePO₄ samples become more regular and smaller with the increase of the hydrothermal reaction temperature. Besides, it has been found that the LiFePO₄ cathode material synthesized at 200 °C showed excellent electrochemical properties which deliver a high initial capacity of 144.25 mAh/g at the rate of 1 C and high capacity retention of 96.7% after 200 cycles. Therefore, this work provides a new strategy for recovery and recycle of the spent LiFePO₄ cathode scraps.

Toward sustainable and systematic recycling of spent rechargeable batteries

A comprehensive and novel view on battery recycling is provided in terms of the science and technology, engineering, and policy.

Recycling supercapacitors based on shredding and mild thermal treatment

Supercapacitors are widely used in electric and hybrid vehicles, wind farm and low-power equipment due to their high specific power density and huge number of charge-discharge cycles. Waste supercapacitors should be recycled according to EU directive 2002/96/EC on waste electric and electronic equipment. This paper describes a recycling approach for end-of-life supercapacitors based on shredding and mild thermal treatment. At first, supercapacitors are shredded using a Retsch cutting mill. The shredded mixture is then undergone thermal treatment at 200°C to recycle the organic solvent contained in the activated carbon electrodes. After the thermal treatment, the mixture is roughly separated using a fluidized bed method to remove the aluminium foil particles and paper particles from the activated carbon particles, which is subsequently put into water for a wet shredding into fine particles that can be re-used. The recycled activated carbon has a BET surface area of up to 1200m(2)/g and the recycled acetonitrile has a high purity.

"Control-alt-delete": rebooting solutions for the E-waste problem

A number of efforts have been launched to solve the global electronic waste (e-waste) problem. The efficiency of e-waste recycling is subject to variable national legislation, technical capacity, consumer participation, and even detoxification. E-waste management activities result in procedural irregularities and risk disparities across national boundaries. We review these variables to reveal opportunities for research and policy to reduce the risks from accumulating e-waste and ineffective recycling. Full regulation and consumer participation should be controlled and reinforced to improve local e-waste system. Aiming at standardizing best practice, we alter and identify modular recycling process and infrastructure in eco-industrial parks that will be expectantly effective in countries and regions to handle the similar e-waste stream. Toxicity can be deleted through material substitution and detoxification during the life cycle of electronics. Based on the idea of "Control-Alt-Delete", four patterns of the way forward for global e-waste recycling are proposed to meet a variety of local situations.

Effect of Cu substitution on structures and electrochemical properties of Li[NiCo1−xCuxMn]1/3O2 as cathode materials for lithium ion batteries

This study on Cu-doped Li[NiCoMn]_1/3O₂ provides support for reusing Cu as a beneficial dopant in the production of metal-doped Li[NiCoMn]_1/3O₂ from spent LIBs.