Recovery of cobalt from spent lithium ion batteries by using acidic and basic extractants in solvent extraction process

Recycling and Reuse of Spent LIBs: Technological Advances and Future Directions

Recovering valuable metals from spent lithium-ion batteries (LIBs), a kind of solid waste with high pollution and high-value potential, is very important. In recent years, the extraction of valuable metals from the cathodes of spent LIBs and cathode regeneration technology are still rapidly developing (such as flash Joule heating technology to regenerate cathodes). This review summarized the studies published in the recent ten years to catch the rapid pace of development in this field. The development, structure, and working principle of LIBs were firstly introduced. Subsequently, the recent developments in mechanisms and processes of pyrometallurgy and hydrometallurgy for extracting valuable metals and cathode regeneration were summarized. The commonly used processes, products, and efficiencies for the recycling of nickel-cobalt-manganese cathodes (NCM/LCO/LMO/NCA) and lithium iron phosphate (LFP) cathodes were analyzed and compared. Compared with pyrometallurgy and hydrometallurgy, the regeneration method was a method with a higher resource utilization rate, which has more industrial application prospects. Finally, this paper pointed out the shortcomings of the current research and put forward some suggestions for the recovery and reuse of spent lithium-ion battery cathodes in the future.

Hydrodynamic features of pulsed solvent extractor for separation of two metals by using the antagonistic effect of solvents

Separating copper and cobalt ions is crucial due to the industry's strategic reliance on both these elements. When the extraction process is able to significantly increase the separation factor, it becomes favorable to separate two ions. However, the presence of Cu(II) ions together with Co(II) hinders the achievement of optimum efficiency when using commonly available extractants. This study conducted the separation of the two elements using both batch and continuous methods in a pilot plant pulsed column equipped with a disc and doughnut structure. The initial step involved optimizing the key variables to maximize the separation factor using the central composite design procedure. The optimization of Cyanex272, Cyphos IL 101 concentrations, and the pH value of the aqueous phase were all adjusted to 0.024 M, 0.046 M, and 7.3, correspondingly. In the following step, the hydrodynamic characteristics and extraction performance were examined in the pulsed column of the pilot plant. The findings indicated that the presence of Cyphos IL 101 resulted in an increased separation factor and efficiency within the column. As a result, the ionic liquid enhances performance without encountering any operational issues. This additive is considered an environmentally friendly solvent and does not cause any negative impacts. Consequently, it is suggested for utilization in continuous industrial processes.

Low-carbon footprint diluents in solvent extraction for lithium-ion battery recycling

This study investigated the influence of the diluent on the extraction properties of three extractants towards cobalt(ii), nickel(ii), manganese(ii), copper(ii), and lithium(i), i.e. Cyanex® 272 (bis-(2,4,4-trimethylpentyl)phosphinic acid), DEHPA (bis-(2-ethyl hexyl)phosphoric acid), and Acorga® M5640 (alkylsalicylaldehyde oxime). The diluents used in the formulation of the extraction solvents are (i) low-odour aliphatic kerosene produced from the petroleum industry (ELIXORE 180, ELIXORE 230, ELIXORE 205 and ISANE IP 175) and (ii) bio-sourced aliphatic diluents (DEV 2138, DEV 2139, DEV 1763, DEV 2160, DEV 2161 and DEV 2063). No influence of the diluent and no co-extraction of lithium(i), nickel(ii), cobalt(ii), manganese(ii) and aluminum were observed during copper(ii) extraction by Acorga M5640. The nature of the diluent influenced more significantly the extraction properties of manganese(ii) by DEHPA as well as cobalt(ii) and nickel(ii) by Cyanex® 272. Life cycle assessment of the diluents shows that the carbon footprints of the investigated diluents followed the following order: (ELIXORE 180, ELIXORE 230, ELIXORE 205) from petroleum industry > kerosene from petroleum industry > diluent produced from tall oil (DEV 2063) > diluents produced from recycled plastic (DEV 2160, DEV 2161) > diluents produced from used cooking oil (DEV 2138, DEV 2139). By taking into account the physicochemical properties of these diluents (viscosity, flashpoint, aromatic content), the extraction properties of Acorga® M5640, DEHPA, Cyanex® 272 in these diluents and the CO2 footprint of the diluents, this study showed DEV2063 and DEV2139 were the best diluents. A low-carbon footprint solvent extraction flowsheet using these diluents was proposed to extract selectively cobalt, nickel, manganese, lithium and copper from NMC black mass of spent lithium-ion batteries.

A process using a thermal reduction for producing the battery grade lithium hydroxide from wasted black powder generated by cathode active materials manufacturing

Recent lithium consumption is doubled in a decade due to the Li-ion battery (LIB) demand for electric vehicles, the energy storage system, etc. The LIBs market capacity is expected to be in strong demand due to the political drive by many nations. Wasted black powders (WBP) are generated from the manufacturing of the cathode active material and spent LIBs. The recycling market capacity is also expected to expand rapidly. This study is to propose a thermal reduction technique for recovering Li selectively. The WBP, containing 7.4 % Li, 62.1 % Ni, 4.5 % Co, and 0.3 % Al, was reduced in a vertical tube furnace using a 10 % H₂ gas as a reducing agent at 750 ºC for 1 h, and 94.3 % of Li was recovered from a water leaching, while other metal values, including Ni and Co remained in the residue. A leach solution was treated in a series of crystallisations, filtering, and washing. An intermediate product was produced and re-dissolved in hot water at 80 ºC for 0.5 h to minimise Li₂CO₃ content into a solution. A final solution was crystallised repeatedly to produce the final product. A 99.5 % of LiOH·H₂O was characterised and passed the impurity specification by the manufacturer as a marketable product. The proposed process is relatively simple to utilise to scale up for bulk production, and it can also be contributed to the battery recycling industry as the spent LIBs are expected to overabundance within the near future. A brief cost evaluation confirms the process feasibility, particularly, for the company that produces cathode active material (CAM) and generates WBP in their own supply chain.

Application of Hydrophobic Deep Eutectic Solvents in Extraction of Metals from Real Solutions Obtained by Leaching Cathodes from End-of-Life Li-Ion Batteries

This paper presents the results of applying hydrophobic deep eutectic solvents (HDESs) for the extraction of metal ions from a real hydrochloric acid solution after leaching the cathodes of three different types of Li-ion batteries. Aliquat 336-, D2EHPA- and menthol-based HDESs developed by us were used in this study. The optimal HCl leaching conditions chosen are 80 °C, 2 M HCl, 6 h, solid:liquid ratio = 1:25. The results of stepwise separation of the major elements using extraction with HDESs are presented. The HDESs used in the cross-current extraction made it possible to extract all elements with extraction ratios above 98%. It was shown that the suggested method could potentially be used in the process of recycling end-of-life Li-ion batteries.

Electrolytic Recovery of Metal Cobalt from Waste Catalyst Pickling Solution

Terephthalic acid production plant uses liquid cobalt-manganese bromide as a catalyst. The waste catalyst is burned with exhaust gas and accumulated in fly ash, which is further pickled and impregnated with a sulfuric acid solution. The resultant solution is rich in cobalt and manganese metal ions with few metal impurities from other petroleum raw materials. An electrochemical reduction method is used to recover cobalt metal from the waste catalyst fly ash pickling solution of terephthalic acid. Various steps have been taken to remove impurities and extract and separate the required pure cobalt metal solution. Afterward, the process of electrolytic reduction smelting is conducted. Variables investigated include current density, electrolyte pH, electrode materials, and electrolytic cell diaphragms, among several others. Results show that the product purity can reach up to 99.84% for the electrolyte feed composition of 21.4 g L^-1 Co, 38.2 g L^-1 Na, and 2.02 g L^-1 Mg.

Solvent Extraction for Separation of 99.9% Pure Cobalt and Recovery of Li, Ni, Fe, Cu, Al from Spent LIBs

In this work, hydrometallurgical recycling of metals from high-cobalt-content spent lithium-ion batteries (LIBs) from laptops was studied using precipitation and solvent extraction as alternative purification processes. Large amounts of cobalt (58% by weight), along with nickel (6.2%), manganese (3.06%) and lithium (6.09%) are present in LiCoO2 and Li2CoMn3O8 as prominent Co-rich phases of the electrode material. The pregnant leach solution (PLS) that was generated by leaching in the presence of 10% H2O2 using 50 g/L pulp density at 80 °C for 4 h contained 27.4 g/L Co, 3.21 g/L Ni, 1.59 g/L Mn and 3.60 g/L Li. The PLS was subjected to precipitation at various pH using 2 M NaOH but the purification performance was poor. To improve the separation of Mn and other impurities and in order to avoid the loss of cobalt and nickel, separation studies were carried out using a solvent extraction technique using di-(2-ethylhexyl) phosphoric acid (D2EHPA) and bis-(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272). Overall, this study examines the fundamentals of separating and synthesizing 99.9% pure Co sulfate from leach liquor of spent laptop LIBs with remarkably high cobalt content.

The Efficiency of Black Mass Preparation by Discharge and Alkaline Leaching for LIB Recycling

Lithium-ion batteries (LIBs) are dangerous to recycle, as they pose a fire hazard when cut and contain various chemical hazards. If recycled safely, LIBs provide a rich secondary source for metals such as lithium and cobalt, while reducing the environmental impact of end-of-life LIBs. Discharging the spent LIBs in a 5 wt.% NaCl electrolyte at room temperature enables their safe dismantling. A sludge was observed to form during the LIB discharging, with a composition of 34.9 wt.% Fe, 35 wt.% O, 17.7 wt.% Al, 6.2 wt.% C, and 4.2 wt.% Na. The average electrolytic solution composition after the first discharge cycle contained only 12.6 mg/L Fe, 4.5 mg/L Li, 2.5 mg/L Mn, and trace amounts of Ni and Co. Separating the active cathode powder from the aluminum cathode with a 10 wt.% NaOH leach produced an aqueous filtrate with an Al metal purity of 99.7%. The leach composition consisted of 9558 mg/L Al, 13 mg/L Li, 8.7 mg/L Co, and trace amounts of Mn and Ni. The hydrometallurgical sample preparation processes in this study enables the production of a pure black mass with less than 0.05 wt.% Co, 0.2 wt.% Li, 0.02 wt.% Mn, and 0.02 wt.% Ni losses from the active cathode material.

Fractionation of Transition Metals by Solvent Extraction and Precipitation from Tannic Acid-Acetic Acid Leachate as a Product of Lithium-Ion Battery Leaching

Solvent extraction and precipitation schemes are applied to isolate copper, cobalt, manganese and nickel from leachate, produced from spent lithium-ion battery leaching using tannic acid-acetic acid as lixiviant. The metal separation and purification were developed based on a ketoxime (LIX® 84-I) and a phosphinic acid (Cyanex® 272) extraction system. Aside from the leachate’s initial pH, which dictates the metal isolation flowsheet, other parameters affecting metal extraction rate, such as phase ratio, extractant concentration, and acid stripping will be evaluated. Copper was selectively removed from leachate at pH 3, using LIX® 84-I 10% v/v followed by cobalt and manganese co-extraction from the raffinate using Cyanex® 272 10% v/v at pH 5. After both metals were stripped using sulfuric acid 0.2 M, manganese was quantitatively precipitated out from the strip solution using potassium permanganate or sodium hypochlorite. Nickel was isolated using LIX® 84-I from raffinate at pH 5, producing a lithium- rich solution for further treatment. No third phase was formed during the extraction, and sulfuric acid was proved suitable for organic phase regeneration.

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.

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.

Removal of Zn(II) and Mn(II) by Ion Flotation from Aqueous Solutions Derived from Zn-C and Zn-Mn(II) Batteries Leaching

The Zn(II) and Mn(II) removal by an ion flotation process from model and real dilute aqueous solutions derived from waste batteries was studied in this work. The research aimed to determine optimal conditions for the removal of Zn(II) and Mn(II) from aqueous solutions after acidic leaching of Zn-C and Zn-Mn waste batteries. The ion flotation process was carried out at ambient temperature and atmospheric pressure. Two organic compounds used as collectors were applied, i.e., m-dodecylphosphoric acid 32 and m-tetradecylphosphoric 33 acid in the presence of a non-ionic foaming agent (Triton X-100, 29). It was found that both compounds can be used as collectors in the ion flotation for Zn(II) and Mn(II) removal process. Process parameters for Zn(II) and Mn(II) flotation have been established for collective or selective removal metals, e.g., good selectivity coefficients equal to 29.2 for Zn(II) over Mn(II) was achieved for a 10 min process using collector 32 in the presence of foaming agent 29 at pH = 9.0.

Selective extraction and separation of Li, Co and Mn from leach liquor of discarded lithium ion batteries (LIBs)

Novel route has been developed to selectively extract lithium (Li), cobalt (Co) and manganese (Mn) from the leach liquor of discarded lithium ion batteries (LIBs) containing 1.4 g/L Cu, 1.1 g/L Ni, 11.9 g/L Co, 6.9 g/L Mn and 1.2 g/L Li. Initially, Cu and Ni were extracted by solvent extraction techniques using 10% LIX 84-IC at equilibrium (Eq.) pH 3 and 4.6, respectively. Subsequently, precipitation studies were carried out at different conditions such as pH, reaction time, precipitant concentration etc., to optimize the parameters for selective precipitation of Co from the leach liquor. Result showed that 99.2% Co was precipitated from the leach liquor (11.9 g/L Co, 6.9 g/L Mn and 1.2 g/L Li) after extraction of Cu and Ni in a range of pH 2.9 to 3.1 using un-diluted ammonium sulfide solution (10% v/v) as a precipitant at 30 °C, while only 0.89% Mn and 0.62% Li were co-precipitated. After Co precipitation, 98.9% Mn was extracted from the filtrate using 10% D2EHPA at equilibrium pH 4.5, and Li remained in raffinate. From the obtained purified solution, metals could be recovered either in a form of salt/metals by precipitation/ evaporation/ electrolysis method.

Review on the Comparison of the Chemical Reactivity of Cyanex 272, Cyanex 301 and Cyanex 302 for Their Application to Metal Separation from Acid Media

Cyanex extractants, such as Cyanex 272, Cyanex 301, and Cyanex 302 have been commercialized and widely used in the extraction and separation of metal ions in hydrometallurgy. Since Cyanex 301 and Cyanex 302 are the derivatives of Cyanex 272, these extractants have similar functional groups. In order to understand the different extraction behaviors of these extractants, an understanding of the relationship between their structure and reactivity is important. We reviewed the physicochemical properties of these extractants, such as their solubility in water, polymerization degree, acidity strength, extraction performance of metal ions, and the interaction with diluent and other extractants on the basis of their chemical structure. Synthetic methods for these extractants were also introduced. This information is of great value in the synthesis of new kinds of extractants for the extraction of metals from a diverse medium. From the literature, the extraction and stripping characteristics of metals by Cyanex 272 and its derivatives from inorganic acids such as HCl, H2SO4, and HNO3 were also reviewed. The replacement of oxygen with sulfur in the functional groups (P = O to P = S group) has two opposing effects. One is to enhance their acidity and extractability due to an increase in the stability of metal complexes, and the other is to make the stripping of metals from the loaded Cyanex 301 difficult.

A Comprehensive Review of Li-Ion Battery Materials and Their Recycling Techniques

In the context of constant growth in the utilization of the Li-ion batteries, there was a great surge in the quest for electrode materials and predominant usage that lead to the retiring of Li-ion batteries. This review focuses on the recent advances in the anode and cathode materials for the next-generation Li-ion batteries. To achieve higher power and energy demands of Li-ion batteries in future energy storage applications, the selection of the electrode materials plays a crucial role. The electrode materials, such as carbon-based, semiconductor/metal, metal oxides/nitrides/phosphides/sulfides, determine appreciable properties of Li-ion batteries such as greater specific surface area, a minimal distance of diffusion, and higher conductivity. Various classifications of the anode materials such as the intercalation/de- intercalation, alloy/de-alloy, and various conversion materials are illustrated lucidly. Further, the cathode materials, such as nickel-rich LiNixCoyMnzO2 (NCM), were discussed. NCM members such as NCM 333, NCM 523 that enabled to advance for NCM622 and NCM81are reported. The nanostructured materials bridged the gap in the realization of next-generation Li-ion batteries. Li-ion batteries’ electrode nanostructure synthesis, performance, and reaction mechanisms were considered with great concern. The serious effects of Li-ion batteries disposal need to be cut significantly to reduce the detrimental effect on the environment. Hence, the recycling of spent Li-ion batteries has gained much attention in recent years. Various recycling techniques and their effect on the electroactive materials are illustrated. The key areas covered in this review are anode and cathode materials and recent advances along with their recycling techniques. In light of crucial points covered in this review, it constitutes a suitable reference for engineers, researchers, and designers in energy storage applications.

Challenges to Future Development of Spent Lithium Ion Batteries Recovery from Environmental and Technological Perspectives

Spent lithium ion battery (LIB) recovery is becoming quite urgent for environmental protection and social needs due to the rapid progress in LIB industries. However, recycling technologies cannot keep up with the exaltation of the LIB market. Technological improvement of processing spent batteries is necessary for industrial application. In this paper, spent LIB recovery processes are classified into three steps for discussion: gathering electrode materials, separating metal elements, and recycling separated metals. Detailed discussion and analysis are conducted in every step to provide beneficial advice for environmental protection and technology improvement of spent LIB recovery. Besides, the practical industrial recycling processes are introduced according to their advantages and disadvantages. And some recommendations are provided for existing problems. Based on current recycling technologies, the challenges for spent LIB recovery are summarized and discussed from technological and environmental perspectives. Furthermore, great effort should be made to promote the development of spent LIB recovery in future research as follows: (1) gathering high-purity electrode materials by mechanical pretreatment; (2) green metals leaching from electrode materials; (3) targeted extraction of metals from electrode materials.

Simultaneous Recovery of Metal Ions and Electricity Harvesting via K-Carrageenan@ZIF-8 Membrane

The spent lithium-ion batteries contain significant amounts of valuable metals such as lithium and cobalt. However, how to effectively recover these valuable metals and minimize environmental pollution simultaneously is still a challenge. In this work, a natural biopolymer K-Carrageenan is introduced into a stable metal-organic framework ZIF-8 to form a composite (KCZ) membrane for selectively separating Li⁺ from Co²⁺ and simultaneously harvesting the concentration gradient energy efficiently. The prepared KCZ membrane shows an Li⁺ ionic conductivity of up to 1.70 × 10^-5 S cm^-1, 5 orders of magnitude higher than 1.1 × 10^-10 S cm^-1 for pristine ZIF-8, with an Li⁺ flux of 0.342 mol m^-2 h^-1 and a selectivity of about 8.29 for Li⁺ over Co²⁺. Moreover, this asymmetric KCZ/anodic alumina oxide membrane exhibits a good output power of up to 3.54 μW when employed as a concentration-gradient energy-harvesting device during the separation process. Hence, the KCZ membrane shows great potential in application for advanced separation and simultaneous concentration gradient energy harvesting.

Regeneration and characterization of LiNi0.8Co0.15Al0.05O2 cathode material from spent power lithium-ion batteries

The use and scrap of lithium ion batteries, especially power lithium ion batteries in China, are increasing every year. Regeneration of spent battery materials is not only important for environmental protection and resource saving, but also for the production of high value-added materials. In this research, spent power lithium-ion battery cathode material LiNi_1-xCo_xO₂ was acid-leached and a polymetallic leaching solution containing Li, Ni, Co, Al and Cu was obtained. Cu was extracted from the leachate by using CP-150 (2-hydroxy-5-nonyl salicylaldehyde oxime). The optimal conditions were found to be organic: aqueous phase ratio (O/A) = 2:1, extraction agent concentration of 30%, and pH = 3. The precursor was prepared by coprecipitation of the leachate after Cu removal. Then, cathode material of lithium nickel cobalt aluminate LiNi_0.8Co_0.15Al_0.05O₂ was synthesized under the optimal conditions of n (precursor): n (lithium carbonate) = 1:1.1, calcination temperature of 800 °C for 15 h. The regenerated LiNi_0.8Co_0.15Al_0.05O₂ product prepared under the optimized conditions was in a pure phase with a layered structure and a smooth surface morphology. The first charge specific capacity was 248.7 mAh/g, and the discharge specific capacity was 162 mAh/g. The interfacial impedance was 119 Ω. The 50th-cycle discharge specific capacity was 149.1 mAh/g, and the capacity retention rate was high as 92%. Therefore, the regenerated cathode material exhibited good performance.

Separation of the cathode materials from the Al foil in spent lithium-ion batteries by cryogenic grinding

An environmentally friendly technology of cryogenic grinding for recovering cathode materials from spent lithium-ion batteries was has been investigated in this paper. Differential Scanning Calorimeter was used to test the glass transition temperature of the organic binder. Advanced analysis techniques, a microcomputer-controlled electronic universal material-testing machine, a low-temperature impact testing machine, scanning electron microscopy and high-resolution 3 Dimension-X-ray microscopy, were utilized to analyze the effect of low temperature on the mechanical properties and morphology of cathode. Results show that the yield strength, tensile strength and impact strength of the current collector is significantly increased at low temperature, that the glass transition temperature of the organic binder is approximately 235 K. Low temperature enhances the strength of the current collector and causes the organic binder to fail. Therefore, cryogenic grinding could realize the selective grinding of the cathode and significantly improve the peel-off of the electrode materials. The peel-off efficiency of cathode materials was improved from 25.03% to 87.29% at the optimum conditions of low temperature pretreatment for 5 min and cryogenic grinding for 30 s. The experiments demonstrate that the cryogenic grinding can obviously facilitate the efficient recovery of cathode materials, revealing a great application prospective for the recycling of spent lithium-ion batteries.

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.

A sustainable process for metal recycling from spent lithium-ion batteries using ammonium chloride

In this paper, a sustainable process to recover valuable metals from spent lithium ion batteries (LIBs) in sulfuric acid using ammonium chloride as reductant was proposed and studied. Being easily reused, ammonium chloride is found to be efficient and posing minor environmental impacts during the overall process. By investigating the effects of a wide range of parameters, e.g., H₂SO₄ concentration, NH₄Cl concentration, temperature, leaching time, and solid-to-liquid mass ratio, the leaching behaviour of Li, Ni, Co, and Mn was systematically investigated. And the leaching mechanism and kinetics were determined by mineralogically characterization of residues at various reaction times and by fitting using different kinetic models. With this research, it is possible to provide a win-win solution to improve the recycling effectiveness of spent LIBs by using waste salt that is easily reused as the reductant.

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.