An innovative approach to recover the metal values from spent lithium-ion batteries

Insights into the evolution of cobalt use and implications through dynamic analysis of cobalt flows and stocks and the recycling potential of cobalt from urban mines in China during 2000-2021

Several countries regard cobalt as a critical material due to its extensive use in clean energy technology and high-tech industries. To comprehensively examine how China's cobalt industry developed and evolved from 2000 to 2021, our study quantified cobalt flows, stocks and the recycling potential of cobalt from China's urban cobalt mines using dynamic material flow analysis. In 2021, China's in-use cobalt stocks for cobalt-containing end products reached 131 kt, of which battery products and superalloys accounted for 83.8% and 8.1%, respectively. The theoretical cumulative recycling potential of cobalt from China's urban cobalt mines reached 204-356 kt between 2000 and 2021 under different scenarios. However, the actual cumulative exploitation of cobalt from urban cobalt mines was 46-80 kt, of which consumer electronics, cemented carbides, and superalloys were the main recycled products. The cumulative exports and imports of cobalt in all commodities reached 558 and 1117 kt, respectively. China exported a large quantity of cobalt chemicals, chemical derivatives and cobalt-containing end products produced from imported cobalt raw materials. China imported 84.7% of the cobalt raw materials consumed domestically, and 32.6% of the domestically produced cobalt-containing end products were exported. Over the entire life cycle of cobalt, cobalt losses totaled 288 kt, with 51.0% of losses coming from refining, and a 73.8% cobalt utilization efficiency was achieved. China recovered 76.7 kt of cobalt, and the recycling rate of cobalt from end-of-life cobalt-containing end products reached 20.0%. The findings can serve as a scientific basis for China's cobalt industry to develop efficiently and economically.

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.

Resource Availability and Implications for the Development of Plug-In Electric Vehicles

Plug-in electric vehicles (PEVs) have immense potential for reducing greenhouse gas emissions and dependence on fossil fuels, and for smart grid applications. Although a great deal of research is focused on technological limitations that affect PEV battery performance targets, a major and arguably equal concern is the constraint imposed by the finite availability of elements or resources used in the manufacture of PEV batteries. Availability of resources, such as lithium, for batteries is critical to the future of PEVs and is, therefore, a topic that needs attention. This study addresses the issues related to lithium availability and sustainability, particularly supply and demand related to PEVs and the impact on future PEV growth. In this paper, a detailed review of the research on lithium availability for PEV batteries is presented, key challenges are pinpointed and future impacts on PEV technology are outlined.

Review of Achieved Purities after Li-ion Batteries Hydrometallurgical Treatment and Impurities Effects on the Cathode Performance

This paper is a product purity study of recycled Li-ion batteries with a focus on hydrometallurgical recycling processes. Firstly, a brief description of the current recycling status was presented based on the research data. Moreover, this work presented the influence of impurities such as Cu, Fe and Mg on recovered cathode materials performance. The impact of the impurities was described depending on their form (metallic or ionic) and concentration. This work also reviewed hydrometallurgical recycling processes depending on the recovered material, obtained purity and recovery methods. This purity data were obtained from both research and battery industry actors. Finally, the purity study was completed by collecting data regarding commercial battery-grade chemical compounds and active lithium cathode materials, including required purity levels and allowed impurity limitations.

A sustainable approach to cathode delamination using a green solvent

Designing an environment-friendly delamination process for an end-of-life (EoL) composite cathode is a crucial step in direct cathode recycling. In this study, the green solvent dimethyl isosorbide (DMI) is explored to extract cathode active materials (AMs) from the Al current collector via dissolving the polyvinylidene fluoride (PVDF) binder. Mechanistic insight suggests that binder removal from the Al substrate proceeds via reducing polymer interchain interaction through DMI penetrating into the PVDF crystalline region. Polymer–solvent interaction may increase via establishing hydrogen bond between PVDF and DMI, which facilitates binder removal. Analytical characterizations including ¹H NMR, FTIR, XRD and SEM-EDS reveal that the molecular, micro, and crystal structures of the recovered cathode AMs, PVDF and Al foil are preserved. This finding is expected to provide a replacement for the toxic organic solvent N-methylpyrrolidone (NMP) and offers an effective, ecofriendly, and sustainable direct cathode recycling approach for spent Li-ion batteries.

A green solvent-based methodology was developed for delaminating cathode active materials from aluminium current collectors in end-of-life Li-ion batteries.

Separation of cathode particles and aluminum current foil in Lithium-Ion battery by high-voltage pulsed discharge Part I: Experimental investigation

To enable effective reuse and recycling processes of spent lithium-ion batteries (LiBs), here we develop a novel electrical method based on a high-voltage pulsed discharge to separate cathode particles and aluminum (Al) foil. A cathode particle sample was mechanically separated from a LiB, cut into 30-mm × 80-mm test pieces, and subjected to a high-voltage electrical pulse discharge from either end in water. At a voltage of 25 kV, 93.9% of the cathode particles separated from the Al foil. These particles were easily recovered by sieving at 2.36 mm because the Al foil retained its shape. Some Al contaminated the particles owing to generation of hot plasma and subsequent shock waves; however, the Al concentration in the recovered cathode particles was limited to 2.95%, which is low enough to allow for further cobalt and nickel recovery by hydrometallurgical processing. The results of heat balance calculations obtained from the current waveforms suggested that polyvinylidene fluoride, the main component of the adhesive in the cathode particle layers, melted and lost its adhesion through Joule heating of the Al foil at the maximum current of 19.0 kA at 25 kV. Almost 99% of the recovered cathode particles maintained their chemical composition and form after separation, and therefore could potentially be directly reused in LiBs.

Potential impact of the end-of-life batteries recycling of electric vehicles on lithium demand in China: 2010-2050

China is expected to realise the complete electrification of traditional internal combustion engine vehicles (ICEVs) by 2050. The rapid development of electric vehicles (EVs) has led to the continuous growth of traction lithium-ion battery (LIB) demand, leading to an increase in demand for specific lithium materials. Therefore, end-of-life (EoL) LIB recycling will largely determine the future lithium availability in China. However, the contribution of recovered lithium to lithium availability is unclear, as the possibility of recovering lithium for reuse in traction LIBs manufacturing is uncertain. To analyse the influence of recovered lithium quality on future lithium availability, we evaluated the potential impact of EoL LIB recycling on lithium demand in China. The results indicated that if new LIB manufacturing cannot use the recovered lithium; the secondary resources would soon exceed the needs of the basic demand (BD) field. In the optimistic scenario, when a LiS battery is used, the oversupply could reach 2.33 Mt by 2050 with a recovery rate of 80%, which is equivalent to 44.05% of China's current lithium reserves of 5.29 Mt. Additionally, when the NCM-G battery is used, the total lithium demand would reach approximately 5.67 Mt in 2031, exceeding China's current lithium reserves. In contrast, if the recovered lithium could be reused in new LIB manufacturing, regardless of the type of LIBs used, the recovered lithium would meet approximately 60% (pessimistic scenario), 53% (neutral scenario), and 49% (optimistic scenario) of the lithium demand for LIBs produced with a recovery rate of 80% by 2050. Consequently, the quality of recovered lithium is very important for its reuse, and it is necessary to develop closed-loop recycling with economic benefits vigorously by improving the quality of recovered lithium. Moreover, much work should be done in recycling infrastructure and industrial policies to promote EoL battery recycling.

Recovery of valuable metals from mixed spent lithium-ion batteries by multi-step directional precipitation

The novel strategy of multi-step directional precipitation is proposed for recovering valuable metals from the leachate of cathode material obtained by mechanical disassembly from mixed spent lithium-ion batteries. Based on thermodynamics and directional precipitation, Mn²⁺ is selectively precipitated under conditions of MRNM (molar ratio of (NH₄)₂S₂O₈ to Mn²⁺) = 3, pH = 5.5 and 80 °C for 90 min. Ni²⁺ was then selectively precipitated using C₄H₈N₂O₂ under conditions of pH = 6, MRCN (molar ratio of C₄H₈N₂O₂ to Ni²⁺) = 2, 30 °C and 20 min. Then, the pH was adjusted to 10 to precipitate Co²⁺ as Co(OH)₂. Finally, Li⁺ was recovered by Na₂CO₃ at 90 °C. The precipitation rates of Mn, Ni, Co, and Li reached 99.5%, 99.6%, 99.2% and 90%, respectively. The precipitation products with high purity can be used as raw materials for industrial production based on characterization. The economical and efficient recovery process can be applied in industrialized large-scale recycling of spent lithium-ion batteries.

Subcritical Water Extraction of Valuable Metals from Spent Lithium-Ion Batteries

The leaching of valuable metals (Co, Li, and Mn) from spent lithium-ion batteries (LIBs) was studied using subcritical water extraction (SWE). Two types of leaching agents, hydrochloric acid (HCl) and ascorbic acid, were used, and the effects of acid concentration and temperature were investigated. Leaching efficiency of metals increased with increasing acid concentration and temperature. Ascorbic acid performed better than HCl, which was attributed to ascorbic acid’s dual functions as an acidic leaching agent and a reducing agent that facilitates leaching reactions, while HCl mainly provides acidity. The chemical analysis of leaching residue by X-ray photoelectron spectroscopy (XPS) revealed that Co(III) oxide could be totally leached out in ascorbic acid but not in HCl. More than 95% of Co, Li, and Mn were leached out from spent LIBs’ cathode powder by SWE using 0.2 M of ascorbic acid within 30 min at 100 °C, initial pressure of 10 bar, and solid-to-liquid ratio of 10 g/L. The application of SWE with a mild concentration of ascorbic acid at 100 °C could be an alternative process for the recovery of valuable metal in spent LIBs. The process has the advantages of rapid reaction rate and energy efficiency that may benefit development of a circular economy.

An original recycling method for Li-ion batteries through large scale production of Metal Organic Frameworks

A concept is proposed for the recycling of Li-ion batteries with an open-loop method that allows to reduce the volume of wastes and simultaneously to produce valuable materials in large amounts (Metal-Organic Frameworks, MOFs). After dissolution of Nickel, Manganese, Cobalt (NMC) batteries in acidic solution (HCl, HNO₃ or H₂SO₄/H₂O₂), addition of organic moieties and a heat treatment, different MOFs are obtained. Solutions after precipitation are analyzed by inductively coupled plasma and materials are characterized by powder X-Ray diffraction, N₂ adsorption, thermogravimetric analysis and Scanning electron microscope. With the use of Benzene-Tri-Carboxylic Acid as ligand, it has been possible to form selectively a MOF, based on Al metallic nodes, called MIL-96 in the literature, and known for its interesting properties in gas storage applications. The supernatant is then used again to precipitate other metals as MOFs after addition of a second batch of ligands. These two other MOFs are based on Cu (known as HKUST-1 in the literature) or Ni-Mn (with a new crystalline structure) depending of conditions. This method shows promising results at the lab scale (15 g of wastes can be converted in 10 g of MOFs), and opens interesting perspectives for the scaled-up production of MOFs.

Extraction of cobalt(ii) by methyltrioctylammonium chloride in nickel(ii)-containing chloride solution from spent lithium ion batteries

Spent lithium batteries contain valuable metals such as cobalt, copper, nickel, lithium, etc. After pretreatment and recovery of copper, only cobalt, nickel and lithium were left in the acid solution. Since the chemical properties of cobalt and nickel are similar, separation of cobalt from a solution containing nickel is technically challenging. In this study, Co(ii) was separated from Ni(ii) by chelating Co(ii) with chlorine ions, Co(ii) was then extracted from the aforementioned chelating complexes by methyltrioctylammonium chloride (MTOAC). The effects of concentrations of chlorine ions in the aqueous phase ([Cl⁻]_aq), MTOAC concentrations in organic phase ([MTOAC]_org), ratios of organic phase to aqueous phase (O/A), and the initial aqueous pH on cobalt separation were studied. The results showed that [Cl⁻]_aq had a significant impact on cobalt extraction efficiency with cobalt extraction efficiency increasing rapidly with the increase in [Cl⁻]_aq. The effect of initial pH on cobalt extraction efficiency was not significant when it varied from 1 to 6. Under the condition of [Cl⁻]_aq = 5.5 M, [MTOAC]_org = 1.3 M, O/A = 1.5, and pH = 1.0, cobalt extraction efficiency reached the maximum of 98.23%, and nickel loss rate was only 0.86%. The stripping rate of cobalt from Co(ii)–MTOAC complexes using diluted hydrochloric acid was 99.95%. By XRD and XRF analysis, the recovered cobalt was in the form of cobalt chloride with the purity of cobalt produced reaching 97.7%. The mode of cobalt extraction was verified to be limited by chemical reaction and the kinetic equation for cobalt extraction was determined to be: R_(Co) = 4.7 × 10⁻³[MTOAC]_(org)^1.85[Co]_(aq)^1.25.

Interception of dearomatized tertiary boronic ester in a diastereoselective [4 + 2] cycloaddition or 1,3-borotopic shift in the presence or absence of “naked” Li⁺, understanding reactivities by activation/strain model, were evaluated by DFT calculations.

Lithium recovery from spent Li-ion batteries using coconut shell activated carbon

Lithium is one of scarce natural resources in the world that need to be preserve. One of the way in preserving the resource is by recovery the rich source of the lithium such as in the spent batteries. It is necessary to develop a recovery method which is efficient and low-cost to be able to recover the lithium in an economic scale. In this study, low-cost activated carbon (AC) from coconut shell charcoal was prepared by chemical and physical activation methods and tested for Li removal from Co, Mn, and Ni ions in semi-continuous columns adsorption experiments. The maximum surface area is 365 m²/g with the total pore volume is 0.148 cm³/g that can be produced by physical activation at 800 °C. In the same activation temperature, activation using KOH has larger ratio of micropore volume than physical activation. Then, the adsorption capacity and selectivity of metal ions were investigated. A very low adsorption capacity of AC for Li ions in batch adsorption mode provides an advantage in column applications for separating Li from other metal ions. The AC sample with chemical activation provided better separation than the samples with physical activation in the column adsorption method. During a certain period of early adsorption (lag time), solution collected from the column outlet was found to be rich in Li due to the fast travel time of this light element, while the other heavier metal ions were mostly retained in the AC bed. The maximum lag time is 97.3 min with AC by KOH activation at 750 °C.

Leaching Behavior Analysis of Valuable Metals from Lithium-Ion Batteries Cathode Material

The paper concerns an approach about using environmental technology and hydrometallurgical process to the recovery of valuable metal from waste cathode material produced during the manufacture of lithium-ion batteries. It is noteworthy that the content of nickel, manganese and cobalt from cathode material are in the extraordinary large proportion. In the acid leaching step, the essential effects of H2SO4 concentration, H2O2 concentration, leaching time, liquid-solid mass ratio and reaction temperature with the leaching percentage were investigated. The cathode material was leached with 2M H2SO4 and 10 vol.% H2O2 at 70 °C and 300 rpm using a liquid-solid mass ratio of 30 ml/g and the leaching efficiency of cobalt was 98.5%, lithium was 99.8%, nickel was 98.6% and manganese was 98.6% under optimum conditions. Kinetic study demonstrates the activation energies for those analyzed metals with Arrhenius equation and manifests the data with hybrid reaction control mechanism. The process was proved from activation energies ranged from 27.79 to 47.25 kJ/mol. Finally, the valuable metals will be leached in sulfuric acid effectively.

A combined process for cobalt recovering and cathode material regeneration from spent LiCoO2 batteries: Process optimization and kinetics aspects

A combined process has been developed for recovering cobalt and regenerating cathode material from leach liquor of spent LiCoO₂ batteries. Cobalt of 98% can be selectively separated from leach liquor using ammonium oxalate of 1.15 (mole ratio) at pH of 2.0, 55 °C, and 40 min. Kinetics analysis indicates that precipitation of cobalt is controlled by a combination of surface chemical reaction and diffusion. The E_a value of precipitation is 19.68 kJ/mol obtained from the second-order model of (1 - a)^-1 = k't + c. Based on the TG/DSC curves of oxidation of cobalt oxalate, it is found that formation of Co₃O₄ oxidized from cobalt oxalate is in according with the model of randomly nucleating followed by nucleus growth. The E_a value is 84.93 kJ/mol that is provided by the suitable model of g(α) = [-ln(1 - α)]^1/3. Then, lithium is recovered from the filtrate as Li₂CO₃ with the purity of 99.5% by precipitation method. Finally, new cathode material with a good electrochemical performance is regenerated using obtained Co₃O₄ and lithium carbonate through solid phase method.

Electrochemical process for electrode material of spent lithium ion batteries

Electrochemical method for recovering cobalt and manganese from electrode materials of spent lithium ion batteries was studied. Electrochemical leaching of cobalt and manganese from electrode material was optimized by varying different process parameters such as time, acid concentration and current density. Both cobalt and manganese could effectively be leached out at a current density of 400A/m² in 3h using 2M sulphuric acid. In the subsequent study, the metallic cobalt and electrolytic manganese dioxides was recovered from the leach liquor at 200A/m², pH 2-2.5 and 90°C after removing aluminum. The commercial feasibility of the study was tested in pilot scale. Overall recovery of Co, Cu and Mn was above 96%, 97% and 99%, respectively.

Supply and demand of some critical metals and present status of their recycling in WEEE

New development and technological innovations make electrical and electronic equipment (EEE) more functional by using an increasing number of metals, particularly the critical metals (e.g. rare and precious metals) with specialized properties. As millions of people in emerging economies adopt a modern lifestyle, the demand for critical metals is soaring. However, the increasing demand causes the crisis of their supply because of their simple deficiency in the Earth's crust or geopolitical constraints which might create political issues for their supply. This paper focuses on the sustainable supply of typical critical metals (indium, rare earth elements (REEs), lithium, cobalt and precious metals) through recycling waste electrical and electronic equipment (WEEE). To illuminate this issue, the production, consumption, expected future demand, current recycling situation of critical metals, WEEE management and their recycling have been reviewed. We find that the demand of indium, REEs, lithium and cobalt in EEE will continuously increasing, while precious metals are decreasing because of new substitutions with less or even without precious metals. Although the generation of WEEE in 2014 was about 41.9 million tons (Mt), just about 15% (6.5 Mt) was treated environmentally. The inefficient collection of WEEE is the main obstacle to relieving the supply risk of critical metals. Furthermore, due to the widespread use in low concentrations, such as indium, their recycling is not just technological problem, but economic feasibility is. Finally, relevant recommendations are point out to address these issues.

Recycled tetrahedron-like CuCl from waste Cu scraps for lithium ion battery anode

The wide applications of metal Cu inevitably resulted in a large quantity of waste Cu materials. In order to recover the useful Cu under the mild conditions and reduce the environmental emission, waste Cu scraps were recycled in the form of CuCl powders with high economic value added (EVA) via the facile hydrothermal route. The recycled CuCl powders were characterized in terms of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The results suggested that the recycled CuCl powders consisted of many regular tetrahedron-like micro-particles. Furthermore, in order to reduce the cost of lithium ion battery (LIB) anode and build the connection of waste Cu scraps and LIB, the recycled CuCl powders were evaluated as the anode active material of LIB. As expected, the reversible discharge capacity was about 171.8mAh/g at 2.0C even after 50 cycles, implying the satisfactory cycle stability. Clearly, the satisfactory results may open a new avenue to develop the circular economy and the sustainable energy industry, which would be very important in terms of both the resource recovery and the environmental protection.

Use of glucose as reductant to recover Co from spent lithium ions batteries

A hydrometallurgical leaching process has been developed for recovery of Co and Li from cathode material (LiCoO₂) collected from spent LIBs using a mix solution of glucose and phosphoric acid. The spent LiCoO₂ before and after leaching process are analyzed by scanning electron microscopy. A leaching rate of about 98% Co and nearly 100% Li is presented with 1.5mol/L phosphoric acid and 0.02mol/L glucose at 80°C in about 2h. During leaching process, glucose was oxidized into monocarboxylic acid with reduction of Co(III) to Co(II). Co in solution was recovered as Co-oxalate after leaching process. Using glucose as reductant to dissolve LiCoO₂ with chelating agent of phosphoric acid is achieved here.

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.

A facile chemical route for recovery of high quality zinc oxide nanoparticles from spent alkaline batteries

Recycling of spent domestic batteries has gained a great environmental significance. In the present research, we propose a new and simple technique for the recovery of high-purity zinc oxide nanoparticles from the electrode waste of spent alkaline Zn-MnO2 batteries. The electrode material was collected by the manual dismantling and mixed with 5M HCl for reaction with a phosphine oxide reagent Cyanex 923® at 250°C for 30min. The desired ZnO nanoparticles were restored from the Zn-Cyanex 923 complex through an ethanolic precipitation step. The recovered particle product with about 5nm diameter exhibited fluorescent properties (emission peak at 400nm) when excited by UV radiation (excitation energy of 300nm). Thus, the proposed technique offered a simple and efficient route for recovering high purity ZnO nanoparticles from spent alkaline batteries.