Innovative application of ionic liquid to separate Al and cathode materials from spent high-power lithium-ion batteries

Maximizing resource recovery: A green and economic strategy for lithium extraction from spent ternary batteries

Spent ternary lithium-ion batteries contain abundant lithium resource, and their proper disposal is conducive to environmental protection and the comprehensive utilization of resources. Separating valuable metals in the ternary leaching solution is the key to ensuring resource recovery. However, the traditional post-lithium extraction strategies, which heavily rely on ion exchange to remove transition metal ions in the leachate, encounter challenges in achieving satisfactory lithium yields and purities. Based on this, this paper proposed a new strategy to prioritize lithium extraction from ternary leachate using "(+) LiFePO4/FePO4 (-)" lithium extraction system. The preferential recovery of lithium can be realized by controlling the potential over 0.1 V versus Standard Hydrogen Electrode (SHE) without introducing any impurity ions. The lithium recovery rate reaches 98.91%, while the rejection rate of transition ions exceeds 99%, and the separation coefficients of lithium to transition metal ions can reach 126. Notably, the resulting lithium-rich liquid can directly prepare lithium carbonate with a purity of 99.36%. It provides a green and efficient strategy for the preferential recovery of lithium from the spent ternary leachate.

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.

Chemical-Free Recycling of Cathode Material and Aluminum Foil from Waste Lithium-Ion Batteries by Combining Plasma and Ultrasonic Technology

With the rapid demand for lithium-ion batteries due to the widespread application of electric vehicles, a significant amount of battery electrode pieces requiring urgent treatment are generated during battery production and disposal. The strong bonding caused by the presence of binders makes it challenging to achieve thorough separation between the cathode active materials and Al foil, posing difficulties in efficient battery material recycling. To address this issue, a plasma-ultrasonically combined physical separation method is proposed in this study. This method utilizes plasma-generated excited-state radicals assisted by ultrasonic waves to separate active materials and current collectors. The results indicate that the binders are effectively decomposed under plasma treatment at 13.56 MHz, 100 W, and 10 min in an oxygen atmosphere, resulting in a separation efficiency of 96.8 wt % for the cathode materials. Characterization results demonstrate that the morphology, crystal structure, and chemical composition of the recycled cathode active materials remain unchanged, facilitating subsequent direct restoration and hydrometallurgical recycling. Simultaneously, the Al foil is also completely recycled for subsequent reuse. Compared with traditional methods of separating cathode active materials and aluminum foil, the method proposed in this study has significant economic and environmental potential. It can promote the recycling of battery materials and the development of sustainable transportation.

A review on spent Mn-containing Li-ion batteries: Recovery technologies, challenges, and future perspectives

Mn-containing Li-ion batteries have become primary power sources for electronic devices and electric vehicles because of their high-energy density, extended cycle life, low cost, and heightened safety. In recent years, Li-ion batteries (LIBs) have undergone rapid updates, paralleling the swift advancement of the lithium battery industry, resulting in a growing accumulation of LIB scraps annually, necessitating comprehensive recovery strategies. This article reviews the recent progress in recovering spent Mn-containing LIBs (SM-LIBs), specifically focusing on LiMn2O4 and ternary LiCoxMnyNizO2 (NCM). Initially, the study analyzes the current resource profile of SM-LIBs and elucidates their service mechanisms. Subsequently, the study explores the recovery of SM-LIBs, discussing various methods such as the hydrometallurgical approach, combined pyrolytic treatment-wet leaching process, bioleaching pathway, and electrochemical extraction. These discussions include recovery processes, reaction principles, and technological features. In addition, this study evaluates the potential applications of these recovery technologies, considering aspects such as complexity, economic viability, energy consumption, environmental sustainability, and scalability. Finally, it summarizes the challenges associated with the comprehensive recovery and resource utilization of SM-LIBs and offers insights into future directions.

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.

Effect of Ion Mass on Dynamic Correlations in Ionic Liquids

Ionic liquids (ILs) are a class of liquid salts with distinct properties such as high ionic conductivity, low volatility, and a broad electrochemical window, making them appealing for use in energy storage applications. The ion-ion correlations are some of the key factors that play a critical role in the ionic conductivity of ILs. In this work, we present the study of the impact of ion mass on ion-ion correlations in ILs, applying a combination of broadband dielectric spectroscopy measurements and molecular dynamics simulations. We examined three ILs with the same cation but different anions to consider three different cases of cation-anion masses: M+ > M-, M+ ≈ M-, and M+ < M-. We applied the momentum conservation approach to estimate the contribution of distinct ion-ion correlations from experimental data and obtained good agreement with direct calculations of distinct ion-ion correlations from molecular dynamics simulations. Our findings reveal that relative ion mass has a strong effect on the distinct ion-ion correlations, leading to swapping of the relative amplitude of distinct cation-cation and anion-anion correlations.

A novel green deep eutectic solvent for one-step selective separation of valuable metals from spent lithium batteries: Bifunctional effect and mechanism

This study used a novel green bifunctional deep eutectic solvent (DES) containing ethylene glycol (EG) and tartaric acid (TA) for the efficient and selective recovery of cathode active materials (LiCoO2 and Li3.2Ni2.4Co1.0Mn1.4O8.3) used in lithium-ion batteries through one-step in-situ separation of Li and Co/Ni/Mn. The effects of leaching parameters on the recovery of Li and Co (ηLi and ηCo) from LiCoO2 are discussed, and the optimal reaction conditions are verified, for the first time, using a response surface method. The results demonstrate that under optimal conditions (120 °C, 12 h, EG to TA mole ratio (MEG:TA) of 5:1, and solid to liquid ratio (RS/L) of 20 g/L), the ηLi from LiCoO2 reached 98.34%, and Co was formed as a purple precipitate of cobalt tartrate (CoC4H4O6), which was transformed into a black powder of Co3O4 after calcination. Notably, the ηLi for DES 5 EG:1 TA was maintained at 80% after five cycles, indicating good cyclic stability. When the as-prepared DES was used to leach the spent active material Li3.2Ni2.4Co1.0Mn1.4O8.3, the in-situ selective separation of Li (ηLi = 98.86%) from other valuable elements such as Ni, Mn, and Co, was achieved, indicating the good selective leaching capacity and practical application potential of the DES.

Effects of incineration and pyrolysis on removal of organics and liberation of cathode active materials derived from spent ternary lithium-ion batteries

Removing organics via thermal treatment to liberate active materials from spent cathode sheets is essential for recovering lithium-ion batteries. In this study, the effects of incineration, N2 pyrolysis, and CO2 pyrolysis on the removal of organics and liberation of ternary cathode active materials (CAMs) were compared. The results indicated that the organics in the spent ternary cathode sheets comprised a residual electrolyte and polyvinylidene fluoride (PVDF) binder. Moreover, the organics could be removed to promote the liberation of CAMs via incineration, N2 pyrolysis, and CO2 pyrolysis. When the temperature was <200 °C, the chemical properties of the volatilized ester electrolyte remained unchanged during both N2 and CO2 pyrolysis, indicating that the electrolyte can be collected by controlling the pyrolysis temperature and condensation. Furthermore, PVDF binder decomposition occurred at 200-600 °C. The optimal temperatures of incineration, N2 pyrolysis, and CO2 pyrolysis were 550, 500, and 450 °C, respectively, and these treatments increased the liberation efficiency of CAMs from 81.49 % to 98.75 %, 99.26 %, and 97.98 %, respectively. In addition, heat-treated CAMs required less time to achieve adequate liberation. Following three thermal treatment processes, the sizes of the CAM particles were mainly concentrated in the ranges of 0.075-0.1 mm and <0.075 mm. Furthermore, for all types of CAMs examined, the Al concentration decreased from 1.09 % to <0.35 %, which increased the separation efficiency and improved the chemical metallurgical performance.

Novel strategy towards in-situ recycling of valuable metals from spent lithium-ion batteries through endogenous advanced oxidation process

Efficient and sustainable recycling of metal resources from spent lithium-ion batteries (LIBs) is critical for the metal resources security and environment protection. However, the intact exfoliation of cathode materials (CMs) from current collectors (Al foils) and selective extraction of Li towards the in-situ and sustainable recycling of cathodes from spent LIBs are still pending issues. A self-activated and ultrasonic-induced endogenous advanced oxidation process (EAOP) was proposed in this study for selective removal of PVDF and in-situ extraction of Li from CMs of waste LiFePO₄ (LFP) to address the above issues. Over 99 wt% CMs can be detached from Al foils after EAOP treatment under the optimized operation conditions. High purity of Al foil can be directly recycled as metallic forms and nearly 100 % of Li can be in-situ extracted from the detached CMs and then recovered as Li₂CO₃ (>99.9 % in purity). With induction and reinforcement of ultrasonic, S₂O₈^2- was self-activated by LFP to generate an increased amount of SO₄^•- radicals that will attack the PVDF binders to ensure their degradation. The degradation pathway of PVDF and density functional theory (DFT) calculation can also support the analytical and experimental results. Then, the complete and in-situ ionization of Li can be achieved by the further oxidization of SO₄^•- radicals from LFP powders. This work provides a novel strategy towards efficient and in-situ recycling of valuable metals from spent LIBs with minimized environmental footprint.

Ultra-fast recovery of cathode materials from spent LiFePO4 lithium-ion batteries by novel electromagnetic separation technology

The separation of electrode materials from current collectors plays a significant role in determining the leaching efficiency of different metals from spent lithium-ion batteries (LIBs). In the presented research, a highly efficient, environmentally sustainable, and cost-effective cathode materials separation strategy was proposed for spent LiFePO₄ batteries. Based on the difference in the thermal expansion coefficient of the binder and aluminum foil, the electromagnetic induction system was examined to harvest cathode materials for the first time, which could provide a high heating rate to erase the mechanical interlocking force between Al foil and coated material, and breaking the chemical bond or Van der Waals forces of the binder. The process avoids the usage of any chemicals such as acids and alkalis, thus eliminating the emission of wastewater. Our system shows ultra-fast separation (3 min) and achieves high-purity of recovered electrode materials and Al foils (99.6% and 99.2%). Furthermore, the morphology and crystalline structure of delaminated electrode materials remain almost the same compared with the pristine materials, which provides a previously unexplored technology to realize sustainable spent battery recycling.

Challenges in Recycling Spent Lithium-Ion Batteries: Spotlight on Polyvinylidene Fluoride Removal

In the recycling of retired lithium-ion batteries (LIBs), the cathode materials containing valuable metals should be first separated from the current collector aluminum foil to decrease the difficulty and complexity in the subsequent metal extraction. However, strong the binding force of organic binder polyvinylidene fluoride (PVDF) prevents effective separation of cathode materials and Al foil, thus affecting metal recycling. This paper reviews the composition, property, function, and binding mechanism of PVDF, and elaborates on the separation technologies of cathode material and Al foil (e.g., physical separation, solid-phase thermochemistry, solution chemistry, and solvent chemistry) as well as the corresponding reaction behavior and transformation mechanisms of PVDF. Due to the characteristic variation of the reaction systems, the dissolution, swelling, melting, and degradation processes and mechanisms of PVDF exhibit considerable differences, posing new challenges to efficient recycling of spent LIBs worldwide. It is critical to separate cathode materials and Al foil and recycle PVDF to reduce environmental risks from the recovery of retired LIBs resources. Developing fluorine-free alternative materials and solid-state electrolytes is a potential way to mitigate PVDF pollution in the recycling of spent LIBs in the EV era.

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.

Selective Extraction of Transition Metals from Spent LiNix Coy Mn1-x-y O2 Cathode via Regulation of Coordination Environment

The complexity of chemical compounds in lithium-ion batteries (LIBs) results in great difficulties in the extraction of multiple transition metals, which have similar physicochemical characteristics. Here, we propose a novel strategy for selective extraction of nickel, cobalt, and manganese from spent LiNi_x Co_y Mn_1-x-y O₂ (NCM) cathode through the regulation of coordination environment. Depending on adjusting the composition of ligand in transition metal complexes, a tandem leaching and separation system is designed and finally enables nickel, cobalt, and manganese to enrich in the form of NiO, Co₃ O₄ , and Mn₃ O₄ with high recovery yields of 99.1 %, 95.1 %, and 95.3 %, respectively. We further confirm that the combination of different transition metals with well-designed ligands is the key to good selectivity. Through our work, fine-tuning the coordination environment of metal ions is proved to have great prospects in the battery recycling industry.

Assessment of recycling methods and processes for lithium-ion batteries

This review discusses physical, chemical, and direct lithium-ion battery recycling methods to have an outlook on future recovery routes. Physical and chemical processes are employed to treat cathode active materials which are the greatest cost contributor in the production of lithium batteries. Direct recycling processes maintain the original chemical structure and process value of battery materials by recovering and reusing them directly. Mechanical separation is essential to liberate cathode materials that are concentrated in the finer size region. However, currently, the cathode active materials are being concentrated at a cut point that is considerably greater than the actual size found in spent batteries. Effective physical methods reduce the cost of subsequent chemical treatment and thereafter re-lithiation successfully reintroduces lithium into spent cathodes. Some of the current challenges are the difficulty in controlling impurities in recovered products and ensuring that the entire recycling process is more sustainable.

Solvent extraction for recycling of spent lithium-ion batteries

Up to now, solvent extraction not only recycle valuable metals (i.e., Ni, Co, Mn and Li) from the leach liquor of spent cathode materials, but also apply to treat spent electrolyte. This paper summarizes the development of solvent extraction in the field of recycling spent lithium-ion batteries (LIBs) from the aspects of principle, technology and industrialization. Meanwhile, the paper also comments on the challenges and opportunities for the solvent extraction facing in the recycling of spent LIBs.

Recycling of LiFePO4 cathode materials from spent lithium-ion batteries through ultrasound-assisted Fenton reaction and lithium compensation

Efficient exfoliation of cathode materials from current collectors for their direct regeneration is the typical bottleneck during spent lithium ion batteries (LIBs) recycling due to the strong adhesion of PVDF (polyvinylidene fluoride) binders. Ultrasound-assisted Fenton reaction was innovatively applied for the selective removal of PVDF binders to recover cathode materials of LiFePO₄ from current collectors and the recovered LiFePO₄ was regenerated through lithium compensation, targeting for the in-situ recycling of cathode materials from spent LIBs. Experimental results suggest that the PVDF binders were adequately degraded by hydroxyl radical (·OH) generated from Fenton's reagent with reinforcement of ultrasound, and about 97% cathode materials can be scrubbed from Al foils under optimized conditions. Detailed analytical results support that the cathode materials peeled off from current collectors are free from contamination of effluent, and the recovered LiFePO₄ can be directly re-fabricated as new cathode materials through lithium compensation with little reduction of electrochemical performances. And the tentative mechanism investigation for pathway of ·OH generation and chemical reactions indicates that ·OH generated from Fenton's reagent with the reinforcement of ultrasound can effectively degrade PVDF binders. This work can be a green and efficient candidate for the in-situ recycling of cathode materials of LiFePO₄ from spent LIBs.

A review on the recycling of spent lithium-ion batteries (LIBs) by the bioleaching approach

This review discusses the latest trend in recovering valuable metals from spent lithium-ion batteries (LIBs) to meet the technological world's critical metal demands. Spent LIBs are a secondary source of valuable metals such as Li (5%-7%), Ni (5%-10%), Co (5%-25%), Mn (5-11%), and non-metal graphite. Recycling is essential for the battery industry to extract valuable critical metals from secondary sources to develop new and novel high-tech LIBs for various applications such as eco-friendly technologies, renewable energy, emission-free electric vehicles, and energy-saving lightings. LIB waste is currently undergoing high-temperature pyrometallurgical or hydrometallurgical processes to recover valuable metals, and these processes have proven to be successful and feasible. These methods, however, are not preferable due to the difficulties in controlling the process, secondary waste produced, high operational cost, and high risk of scaling up. Biotechnological approaches can be promising alternatives to pyrometallurgical and hydrometallurgical technologies in metal recovery from LIB waste. Microbiological metal dissolution or bioleaching has gained popularity for metal extraction from ores, concentrates, and recycled or residual materials in recent years. This technology is eco-friendly, safe to handle, and reduces operating costs and energy demands. The pre-treatment process (material preparation), microorganisms used in the bioleaching of LIBs, factors influencing the bioleaching process, methods of enhancing the leaching efficiency, regeneration of electrode materials, and future aspects have been discussed in detail.

Uncovering the in-use metal stocks and implied recycling potential in electric vehicle batteries considering cascaded use: a case study of China

With the rapid promotion of new energy vehicles, in-use electric vehicle batteries (EVBs) are becoming an important component of urban mining. This paper analyzed the metal stocks in EVBs in China from 2009 to 2019 using a bottom-up method, which focused on the in-use stock of seven main metals, namely, nickel, cobalt, manganese, lithium, copper, aluminum, and iron, in primary use stage and secondary use stage of three EVB types, namely, lithium nickel manganese cobalt oxide battery (NMC), lithium iron phosphate battery (LFP), and lithium manganese oxide battery (LMO). It was found that the rapid development of electric vehicles (EVs) contributed to a dramatic increase in in-use metal stocks from 0.7 kt in 2009 to 1.1 Mt in 2019. To assess the increase, three scenarios simulating metal stocks in EVBs from 2020 to 2030 were analyzed, namely, baseline, NMC-dominated, and LFP-dominated, and results indicated that metal stocks will reach 20.6 Mt, 23.2 Mt, and 17.9 Mt, respectively, by 2030. Across the scenarios there is little proportional difference in metal stocks between the two use stages. The proportion of the three EVB types correlates to the development trend of EVB technology under each corresponding scenario. Besides, the in-use metal stocks in EVBs have high implied recycling potential and environmental benefit. The recycling potential of these seven metals is 1.0 Mt in 2019, and it will reach 20.0 Mt, 22.6 Mt, and 17.4 Mt, respectively, in 2030 under the three scenarios. The results reveal the current status and evolution characteristics of metal stocks in EVBs in China, and provide data for material flow analysis and life cycle management of EVBs.

Converting Spent LiFePO4 Battery into Zeolitic Phosphate for Highly Efficient Heavy Metal Adsorption

Developing efficient recycling technologies for large-scale spent batteries is the key to build a zero-waste city. Herein, a [Al_8.5Fe_0.5P₁₂O₄₈]·[C₂₄H₇₂N₁₆]·[Li·4H₂O]·[12H₂O] (AlFePO-Li) zeolite, crystallizing in space group I4̅3m with a = 16.6778(3) Å, has been constructed via the hydrothermal treatment of spent LiFePO₄ battery. Benefiting from the three-dimensional 12-member-ring channels in its structure and chemical adsorption, excellent Pb²⁺ removal capacity up to 723.8 mg g^-1 has been achieved. Detailed adsorption mechanism study revealed that the cation exchange capacity is significantly contributed by ion exchange of the protonated organic amine cations in the zeolite channel and the protons from the framework dangling phosphate group. This work demonstrates a novel method of reutilizing spent LIBs to construct zeolite for heavy metal removal. It is of great importance to achieve sustainable development based on the "resource utilization" and "trash-to-treasure" strategy.

On the Solubility and Stability of Polyvinylidene Fluoride

This literature review covers the solubility and processability of fluoropolymer polyvinylidine fluoride (PVDF). Fluoropolymers consist of a carbon backbone chain with multiple connected C-F bonds; they are typically nonreactive and nontoxic and have good thermal stability. Their processing, recycling and reuse are rapidly becoming more important to the circular economy as fluoropolymers find widespread application in diverse sectors including construction, automotive engineering and electronics. The partially fluorinated polymer PVDF is in strong demand in all of these areas; in addition to its desirable inertness, which is typical of most fluoropolymers, it also has a high dielectric constant and can be ferroelectric in some of its crystal phases. However, processing and reusing PVDF is a challenging task, and this is partly due to its limited solubility. This review begins with a discussion on the useful properties and applications of PVDF, followed by a discussion on the known solvents and diluents of PVDF and how it can be formed into membranes. Finally, we explore the limitations of PVDF's chemical and thermal stability, with a discussion on conditions under which it can degrade. Our aim is to provide a condensed overview that will be of use to both chemists and engineers who need to work with PVDF.

A promising selective recovery process of valuable metals from spent lithium ion batteries via reduction roasting and ammonia leaching

In this study, a promising process has been developed for selective recovery of valuable metals from spent lithium ion batteries (LIBs). First, reduction roasting which used spent anode powder as reduction agent and water immersion are applied to preferentially recover lithium. Subsequently, an ammonia leaching method is adopted to eff ;ectively separate nickel and cobalt from water immersion residue. Results indicate that Li₂CO₃, (NiO)_m·(MnO)_n, Ni, Co are the ultimate reduction products at 650 °C for 1 h with 5% anode powder. 82.2 % Li is preferentially leached via water immersion after reduction roasting and Li₂CO₃ products are obtained by evaporation crystallization. Thermodynamics shows that reducing ammonia leaching is feasible for water immersion residue. Amounts of 97.7 % Ni and 99.1 % Co can be selectively leached by NH_3·H₂O and (NH₄)₂SO₃ while Mn remain in the residue as (NH₄)₂Mn(SO₃)_2·H₂O, (NH₄)₂Mn(SO₄)_2·6H₂O and (NH₄)₂Mn₂(SO₃)₃ under the optimized conditions. Ammonia leaching kinetic show the activation energy of Ni and Co is 84.44 kJ/mol and 91.73 kJ/mol, which indicate the controlling steps are the chemical reaction. Summarily, the whole process achieves the maximum degree of selective recovery and reduces the environmental pollution caused by the multistep purification.

Recycling of cathode from spent lithium iron phosphate batteries

We demonstrate the concept of fabricating new lithium ion batteries from recycled spent 18650 lithium ion batteries (LIB). LiFePO₄ cathode was extracted from these spent LIB using combined approach of pre-treatment, mechanical treatment and hydrometallurgical process wherein weak organic acids, such as methyl sulfonic acid (MSA) and p-toluene sulfonic acid (TSA), were employed for the first time for leaching at room temperature of metal ions instead of conventional strong acids. High leaching efficiencies (95%) were obtained for extraction of Li and Fe using these acids from black mass. Reuse of these extracted metal ions is also demonstrated by precipitating them and synthesizing LiFePO₄ cathode. Structural characterization showed the formation of single-phase LiFePO₄ and electrochemical evaluation of this cathode in a LiFePO₄/Li half-cell exhibited a capacity of 93 mA h/g and 80 mA h/g at 0.2C and 1C rate respectively with good cycle stability.

Pyrolysis characteristics of cathode from spent lithium-ion batteries using advanced TG-FTIR-GC/MS analysis

Thermal treatment offers an alternative method for the separation of Al foil and cathode materials during spent lithium-ion batteries (LIBs) recycling. In this work, the pyrolysis behavior of cathode from spent LIBs was investigated using advanced thermogravimetric Fourier transformed infrared spectroscopy coupled with gas chromatography-mass spectrometer (TG-FTIR-GC/MS) method. The fate of fluorine present in spent batteries was probed as well. TG analysis showed that the cathode decomposition displayed a three-stage process. The temperatures of maximum mass loss rate were located at 470 °C and 599 °C, respectively. FTIR analysis revealed that the release of CO₂ increased as the temperature rose from 195 to 928 °C. However, the evolution of H₂O showed a decreasing trend when the temperature increased to above 599 °C. The release of fluoride derivatives also exhibited a decreasing trend, and they were not detected after temperatures increasing to above 470 °C. GC-MS analysis indicated that the release of H₂O and CO displayed a similar trend, with larger releasing intensity at the first two stages. The evolution of 1,4-difluorobenzene and 1,3,5-trifluorobenzene also displayed a similar trend-larger releasing intensity at the first two stages. However, the release of CO₂ showed a different trend, with the largest release intensity at the third stage, as did the release of 1,2,4-trifluorobenzene, with the release mainly focused at the temperature of 300-400 °C. The release intensities of 1,2,4-trifluorobenzene and 1,3,5-trifluorobenzene were comparable, although smaller than that of 1,4-difluorobenzene. This study will offer practical support for the large-scale recycling of spent LIBs.

Recycle, Recover and Repurpose Strategy of Spent Li-ion Batteries and Catalysts: Current Status and Future Opportunities

The disposal of hazardous waste of any form has become a great concern for the industrial sector due to increased environmental awareness. The increase in usage of hydroprocessing catalysts by petrochemical industries and lithium-ion batteries (LIBs) in portable electronics and electric vehicles will soon generate a large amount of scrap and create significant environmental problems. Like general electronic wastes, spent catalysts and LIBs are currently discarded in municipal solid waste and disposed of in landfills in the absence of policy and feasible technology to drive alternatives. Such inactive catalyst materials and spent LIBs not only contain not only hazardous heavy metals but also toxic and carcinogenic chemicals. Besides polluting the environment, these systems (spent catalysts and LIBs) contain valuable metals such as Ni, Mo, Co, Li, Mn, Rh, Pt, and Pd. Therefore, the extraction and recovery of these valuable metals has significant importance. In this Review, we have summarized the strategies used to recover valuable (expensive) as well as cheap metals from secondary resources-especially spent catalysts and LIBs. The first section contains the background and sources of LIBs and catalyst scraps with their current recycling status, followed by a brief explanation of metal recovery methods such as pyrometallurgy, hydrometallurgy, and biometallurgy. The recent advances achieved in these methods are critically summarized. Thus, the Review provides a guide for the selection of adequate methods for metal recovery and future opportunities for the repurposing of recovered materials.

Progress and Status of Hydrometallurgical and Direct Recycling of Li-Ion Batteries and Beyond

An exponential market growth of Li-ion batteries (LIBs) has been observed in the past 20 years; approximately 670,000 tons of LIBs have been sold in 2017 alone. This trend will continue owing to the growing interest of consumers for electric vehicles, recent engagement of car manufacturers to produce them, recent developments in energy storage facilities, and commitment of governments for the electrification of transportation. Although some limited recycling processes were developed earlier after the commercialization of LIBs, these are inadequate in the context of sustainable development. Therefore, significant efforts have been made to replace the commonly employed pyrometallurgical recycling method with a less detrimental approach, such as hydrometallurgical, in particular sulfate-based leaching, or direct recycling. Sulfate-based leaching is the only large-scale hydrometallurgical method currently used for recycling LIBs and serves as baseline for several pilot or demonstration projects currently under development. Conversely, most project and processes focus only on the recovery of Ni, Co, Mn, and less Li, and are wasting the iron phosphate originating from lithium iron phosphate (LFP) batteries. Although this battery type does not dominate the LIB market, its presence in the waste stream of LIBs causes some technical concerns that affect the profitability of current recycling processes. This review explores the current processes and alternative solutions to pyrometallurgy, including novel selective leaching processes or direct recycling approaches.

Stepwise recycling of valuable metals from Ni-rich cathode material of spent lithium-ion batteries

A novel and efficient approach for stepwise recycling of valuable metals from Ni-rich cathode material is developed. First, the spent cathode materials are leached by H₂SO₄ + H₂O₂ solution. The leaching efficiencies of lithium, nickel, manganese and cobalt reach almost 100%, 100%, 94% and 100%, respectively, under the conditions of 2 M sulfuric acid, 0.97 M hydrogen peroxide, 10 ml·g^-1 liquid-solid ratio, 30 min and 80 °C. Then, manganese and cobalt are co-extracted from the leaching liquor with PC88A, while almost 99% nickel and 100% lithium remain in the raffinate followed by being separated from each other by solvent extraction with neodecanoic acid (Versatic 10). The results show that 98% manganese and over 90% cobalt are co-extracted at pH = 5, 30 vol% PC88A and volume ratio of oil to water (O:A) = 2:1, while 100% nickel is separated from lithium under the optimum extraction conditions of initial pH = 4, O:A = 1:3 and 30 vol% Versatic 10. Finally, cobalt and manganese in the strip liquor of co-extraction are separated by selective precipitation method. Over 90% manganese is separated from cobalt under the conditions of pH = 0.5, 0.076 M KMnO₄, 80 °C and 60 min.

Advances in mineral processing technologies related to iron, magnesium, and lithium

Exploitation and utilization of mineral resources have played a vital role in China’s rapid economic developments. Although the history of mineral processing is quite long, technologies in this field have varied with the changes of market demands. This is particularly the case for minerals whose high-grade deposits are depleting. The aim of this review is to present our recent efforts on developing new routes for the utilization of low-grade minerals, such as iron ores and brine-containing lithium. The emphasis on the two minerals lies in the fact that iron plays a vital role in modern-day civilization and lithium is a key component in electric vehicles for transportation. Furthermore, the utilization of magnesium chloride reserves, one of the largest wastes in western China, as raw materials for fabrication of functional materials is also included in this review.

Manganese-based multi-oxide derived from spent ternary lithium-ions batteries as high-efficient catalyst for VOCs oxidation

Valuable metals such as manganese, cobalt, nickel and copper are recycled from spent ternary lithium-ions batteries (LiBs) and are considered as the active metal precursor to prepare based-manganese multi oxide for VOCs oxidation. The results of characterization analysis indicate that the catalyst from spent LiBs shows larger specific surface area of 26.80 m²/g as well as abundant mesoporous structures on the surface, higher molar ratio of Mn⁴⁺/Mn³⁺ (0.70) and O_latt/O_ads (1.68), better low-temperature reductivity and stronger intensity of weak acid sites in comparison with those of pure manganese oxides. The evaluation experiments show that the catalyst from waste exhibits more excellent catalytic performance of toluene combustion in comparison with pure manganese oxides. Furthermore, the presence of considerable amount of lithium and aluminum ions can severely weaken the catalytic activity while the co-existence of nickel, cobalt and copper ions contribute a lot to facilitate the catalytic behavior. In-situ DRIFT study implies that the introduction of lithium, aluminum, nickel, copper and cobalt into pure manganese oxides can facilitate toluene conversion to various extents, following the consecutive steps via benzyl species, benzoyl oxide species, benzaldehyde species, benzoate species and the primary intermediates are benzoate species.

A low-toxicity and high-efficiency deep eutectic solvent for the separation of aluminum foil and cathode materials from spent lithium-ion batteries

The separation of cathode materials from aluminum (Al) foil is a key issue worthy of attention in the process of resource utilization of spent lithium-ion batteries (LIBs). Traditional technologies for the Al foil and cathode materials separation have the disadvantages of the use of corrosive acid/alkali, release of HF hazards, and environment and healthy risks of the toxicity reagent. In this study, a low-toxicity, high-efficiency, and low-cost deep eutectic solvent (DES), choline chloride-glycerol, was synthesized and applied to solving the separation dilemma of Al foil and cathode materials in spent LIBs. The experimental results show that separation of the Al foil and cathode materials can be achieved under optimal conditions designed by the response surface method: heating temperature 190 ℃, choline chloride: glycerol molar ratio 2.3:1, and heating time 15.0 min; the peeling percentage of cathode material can reach 99.86 wt%. Mechanism analysis results confirm that the separation of Al foil and cathode materials was the result of the deactivation of the organic binder polyvinylidene fluoride (PVDF), which can be attributed to an alkali degradation process caused by the attack of the hydroxide of choline chloride on the acidic hydrogen atom in PVDF.

A Structured Literature Review on Obsolete Electric Vehicles Management Practices

The use of electricity for transportation needs offers the chance to replace fossil fuels with greener energy sources. Potentially, coupling sustainable transports with Renewable Energies (RE) could reduce significantly both Greenhouse Gas (GHG) emissions and the dependency on oil imports. However, the expected growth rate of Electric Vehicles (EVs) could become also a potential risk for the environment if recycling processes will continue to function in the current way. To this aim, the paper reviews the international literature on obsolete EV management practices, by considering scientific works published from 2000 up to 2019. Results show that the experts have paid great attention to this topic, given both the critical and valuable materials embedded in EVs and their main components (especially traction batteries), by offering interesting potential profits, and identifying the most promising End-of-Life (EoL) strategy for recycling both in technological and environmental terms. However, the economics of EV recycling systems have not yet been well quantified. The intent of this work is to enhance the current literature gaps and to propose future research streams.

Maleic, glycolic and acetoacetic acids-leaching for recovery of valuable metals from spent lithium-ion batteries: leaching parameters, thermodynamics and kinetics

Environmentally friendly acid-leaching processes with three organic acids (maleic, glycolic and acetoacetic) were developed to recover valuable metals from the cathodic material of spent lithium-ion batteries (LiCoO₂). The leaching efficiencies of Li and Co by the maleic acid were 99.58% and 98.77%, respectively. The leaching efficiencies of Li and Co by the glycolic acid were 98.54% and 97.83%, while those by the acetoacetic acid were 98.62% and 97.99%, respectively. The optimal acid concentration for the maleic acid-, glycolic acid- and acetoacetic acid-leaching processes were 1, 2 and 1.5 mol l^-1, respectively, while their optimal H₂O₂ concentrations were 1.5, 2 and 1.5 vol%, respectively. The optimal solid/liquid ratio, temperature and reaction time for the leaching process of the three organic acids was the same (10 g l^-1, 70°C, 60 min). The thermodynamic formation energy of the leaching products and the Gibbs free energy of the leaching reactions were calculated, and the kinetic study showed that the leaching processes fit well with the shrinking-core model. Based on the comparison in the leaching parameters, the efficacy and availability of the three acids is as follows: maleic acid > acetoacetic acid > glycolic acid.

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.

Lithium recycling and cathode material regeneration from acid leach liquor of spent lithium-ion battery via facile co-extraction and co-precipitation processes

A novel process for extracting transition metals, recovering lithium and regenerating cathode materials based on facile co-extraction and co-precipitation processes has been developed. 100% manganese, 99% cobalt and 85% nickel are co-extracted and separated from lithium by D2EHPA in kerosene. Then, Li is recovered from the raffinate as Li₂CO₃ with the purity of 99.2% by precipitation method. Finally, organic load phase is stripped with 0.5M H₂SO₄, and the cathode material LiNi_1/3Co_1/3Mn_1/3O₂ is directly regenerated from stripping liquor without separating metal individually by co-precipitation method. The regenerative cathode material LiNi_1/3Co_1/3Mn_1/3O₂ is miro spherical morphology without any impurities, which can meet with LiNi_1/3Co_1/3Mn_1/3O₂ production standard of China and exhibits good electrochemical performance. Moreover, a waste battery management model is introduced to guarantee the material supply for spent battery recycling.

Direct regeneration of cathode materials from spent lithium iron phosphate batteries using a solid phase sintering method

A direct regeneration of cathode materials from spent LiFePO₄ batteries using a solid phase sintering method has been proposed in this article.

Recycling of spent lithium-ion battery cathode materials by ammoniacal leaching

As the production and consumption of lithium ion batteries (LIBs) increase, the recycling of spent LIBs appears inevitable from an environmental, economic and health viewpoint. The leaching behavior of Ni, Mn, Co, Al and Cu from treated cathode active materials, which are separated from a commercial LIB pack in hybrid electric vehicles, is investigated with ammoniacal leaching agents based on ammonia, ammonium carbonate and ammonium sulfite. Ammonium sulfite as a reductant is necessary to enhance leaching kinetics particularly in the ammoniacal leaching of Ni and Co. Ammonium carbonate can act as a pH buffer so that the pH of leaching solution changes little during leaching. Co and Cu can be fully leached out whereas Mn and Al are hardly leached and Ni shows a moderate leaching efficiency. It is confirmed that the cathode active materials are a composite of LiMn2O4, LiCoxMnyNizO2, Al2O3 and C while the leach residue is composed of LiNixMnyCozO2, LiMn2O4, Al2O3, MnCO3 and Mn oxides. Co recovery via the ammoniacal leaching is believed to gain a competitive edge on convenitonal acid leaching both by reducing the sodium hydroxide expense for increasing the pH of leaching solution and by removing the separation steps of Mn and Al.

A sustainable process for the recovery of valuable metals from spent lithium-ion batteries

In this work, an eco-friendly and hydrometallurgical process for the recovery of cobalt and lithium from spent lithium-ion batteries has been proposed, which includes pretreatment, citric acid leaching, selective chemical precipitation and circulatory leaching. After pretreatment (manual dismantling, N-methyl pyrrolidone immersion and calcination), Cu and Al foils are recycled directly and the cathode active materials are separated from the cathode efficiently. Then, the obtained cathode active materials (waste LiCoO2) was firstly leached with 1.25 mol l(-1) citric acid and 1 vol.% H2O2 solution. Then cobalt was precipitated using oxalic acid (H2C2O4) under a molar ratio of 1:1.05 (H2C2O4: Co(2+)). After filtration, the filtrate (containing Li(+)) and H2O2 was employed as a leaching agent and the optimum conditions are studied in detail. The leaching efficiencies can reach as high as 98% for Li and 90.2% for Co, respectively, using filter liquor as leaching reagent under conditions of leaching temperature of 90°C, 0.9 vol.% H2O2 and a solid-to-liquid ratio of 60 ml g(-1) for 35 min. After three bouts of circulatory leaching, more than 90% Li and 80% Co can be leached under the same leaching conditions. In this way, Li and Co can be recovered efficiently and waste liquor re-utilization is achievable with this hydrometallurgical process, which may promise both economic and environmental benefits.

Novel approach to recover cobalt and lithium from spent lithium-ion battery using oxalic acid

With the booming of consumer electronics (CE) and electric vehicle (EV), a large number of spent lithium-ion battery (LIBs) have been generated worldwide. Resource depletion and environmental concern driven from the sustainable industry of CE and EV have motivated spent LIBs should be recovered urgently. However, the conventional process combined with leaching, precipitating, and filtering was quite complicated to recover cobalt and lithium from spent LIBs. In this work, we developed a novel recovery process, only combined with oxalic acid leaching and filtering. When the optimal parameters for leaching process is controlled at 150 min retention time, 95 °C heating temperature, 15 g L(-1) solid-liquid ratio, and 400 rpm rotation rate, the recovery rate of lithium and cobalt from spent LIBs can reach about 98% and 97%, respectively. Additionally, we also tentatively discovered the leaching mechanism of lithium cobalt oxide (LiCoO2) using oxalic acid, and the leaching order of the sampling LiCoO2 of spent LIBs. All the obtained results can contribute to a short-cut and high-efficiency process of spent LIBs recycling toward a sound closed-loop cycle.