A method for recovering valuable metals from waste batteries containing nickel, manganese, and cobalt and for using the recovered valuable metals to obtain cathode material

Abstract

The invention relates to a method for the recovery of valuable metals and the production of lithium carbonate by removing impurities (such as Fe, Cu, Al) present in the black mass obtained from nickel-manganese-cobalt-containing waste batteries at high efficiencies. In another aspect, the invention relates to the reuse of the obtained lithium carbonate and valuable metals in the production of cathode materials.

Description

[0001] A METHOD FOR RECOVERING VALUABLE METALS FROM WASTE BATTERIES CONTAINING NICKEL, MANGANESE, AND COBALT AND FOR USING THE RECOVERED VALUABLE METALS TO OBTAIN CATHODE MATERIAL

[0002] TECHNICAL FIELD

[0003] The invention relates to a method for the recovery of valuable metals and the production of lithium carbonate by removing impurities (such as Fe, Cu, Al) present in the black mass obtained from nickel-manganese-cobalt-containing waste batteries at high efficiencies. In another aspect, the invention relates to the reuse of the obtained lithium carbonate and valuable metals in the production of cathode materials.

[0004] PRIOR ART

[0005] Nickel-manganese-cobalt batteries (abbreviated as NMC) are a type of lithium-ion battery technology and consist of a compound containing nickel, manganese, and cobalt as the cathode material. These batteries are widely used in applications such as electric vehicles, energy storage systems, and consumer electronics due to their high energy density, long service life, and charge-discharge cycles. These batteries become waste when they reach the end of their service life, when their energy storage capacity is significantly reduced, or when they lose functionality due to physical damage.

[0006] Waste NMC batteries may cause environmental and technical problems due to the presence of impurities such as copper, iron, and aluminum, in addition to the valuable metals nickel, manganese, cobalt, and lithium they contain. When the metals in these batteries are released into the environment in an uncontrolled manner, they pollute soil and water resources, causing environmental harm. Moreover, during the processing of waste batteries, the separation of impurities can be difficult and costly, which may reduce the efficiency of recovery processes. Subjecting NMC batteries to recycling processes ensures the conservation of natural resources through the reuse of these strategic metals, reduces battery production costs, and provides a sustainable circular economy. At the same time, it offers an environmentally friendly solution for the energy storage industry by minimizing the environmental impacts of waste.In the prior art, the recycling of waste NMC batteries is generally carried out by pyrometallurgical, hydrometallurgical, and mechanical separation methods. In pyrometallurgical methods, the batteries are melted at high temperatures and the metals are separated physically or chemically. In this method, metals such as nickel, cobalt, and copper can be recovered, whereas metals such as lithium and manganese are generally lost. High energy consumption and greenhouse gas emissions cause environmental harm, and additionally, some of the valuable metals are lost. In hydrometallurgical methods, the batteries are leached in acid solutions to convert them into metal ions, which are then purified by precipitation, solvent extraction, or electrochemical methods. This method can provide more selective separation; however, it requires high chemical consumption. The amount of chemicals used results in both environmental and economic costs, and the separation of impurities during the process can pose difficulties. Mechanical separation is based on physically breaking down the batteries and separating them into their components, but it is not sufficient for the recovery of pure metals. All of these methods have technical disadvantages such as inefficiency, high cost, and lack of environmental sustainability. Therefore, there is a need for more efficient, environmentally friendly, and low-cost recycling methods.

[0007] As a result, all of the problems mentioned above have made it necessary to develop environmentally friendly and low-cost recovery methods that achieve higher efficiency.

[0008] BRIEF DESCRIPTION OF THE INVENTION

[0009] The present invention relates to a method for the recovery of NMC waste batteries in order to eliminate the disadvantages mentioned above and to provide new advantages to the relevant technical field.

[0010] An object of the invention is to provide a method by which valuable metals can be recovered from NMC waste batteries with high efficiency. Accordingly, the recovery of strategic metals such as nickel, manganese, and cobalt from waste batteries at high purity and with low losses is ensured. In this way, metals that can be used in next-generation energy storage systems are obtained, and the economic value of waste batteries is increased.

[0011] An object of the invention is to provide a method by which impurities such as Al, Fe, and Cu can be removed from NMC waste batteries with high efficiency. Thus, effective separation of impurities such as iron, aluminum, and copper is achieved through pHadjustments and specific precipitation techniques. The removal of impurities increases the purity of the recovered valuable metals while also improving the efficiency of the recycling process. In this manner, it becomes possible for the recovered metals to be of higher quality and suitable for use.

[0012] An object of the invention is to provide a method in which chemical consumption is reduced, operations can be carried out with low energy, and environmental sustainability is ensured. Thus, the amount of chemical substances used in recycling processes is minimized, and a method that minimizes energy consumption is developed. This method offers both an economical and sustainable recycling solution by reducing environmental impacts. In addition, environmentally friendly processes provide a recovery approach that is compatible with circular economy goals.

[0013] An object of the invention is to provide a method by which lithium carbonate can be obtained from NMC waste batteries with high efficiency. Thus, through pH adjustments, lithium (Li) is precipitated in the form of Li2CO3(lithium carbonate) with high purity. Lithium carbonate becomes reusable particularly in the production of lithium-ion batteries, thereby providing an important input for energy storage systems.

[0014] An object of the invention is to provide a method by which the valuable metals and lithium carbonates obtained from NMC waste batteries can be reused as raw materials in the production of cathode materials.

[0015] DETAILED DESCRIPTION OF THE INVENTION

[0016] In this detailed description, the invention relates to a method for the recovery of valuable metals and lithium carbonates from NMC waste batteries, and is explained with examples intended solely to provide a better understanding of the subject matter, without creating any limiting effect.

[0017] The NMC batteries referred to in the invention are a type of lithium-ion battery technology and consist of a chemical composition containing nickel, manganese, and cobalt as the cathode material. These batteries may become obsolete due to reaching the end of their service life, a significant decrease in energy storage capacity, or the occurrence of physical damage. Within the scope of the invention, such obsolete NMC batteries are used as a raw material source.In the present invention, the final product intended to be obtained is recovered nickel-manganese-cobalt compounds. Another objective of the invention is the production of lithium carbonate compounds from the waste NMC batteries in which the recovery processes are carried out.

[0018] In this invention, the term “valuable metals” is used. By valuable metals, nickel, manganese, and cobalt metals present in waste batteries are meant. On the other hand, lithium metal is likewise considered a valuable metal.

[0019] This invention is directed to the effective separation of components considered as impurities in waste batteries. Impurities consist of metals that negatively affect the purity of the targeted valuable metals and the recovery efficiency in recycling processes. In this context, metals such as copper, iron, and aluminum, and their compounds, are meant as impurities. Said metals cause various problems in recovery processes. In chemical processes, these metals enter the solution and cause undesired reactions, while in physical processes they hinder separation, thereby reducing process efficiency.

[0020] Accordingly, the method for obtaining the valuable metals mentioned from NMC battery waste according to the present invention comprises the following process steps:

[0021] Procurement of waste

[0022] In this invention, the raw materials used as waste are obtained from NMC-type lithium-ion batteries that have reached the end of their service life or have lost their functionality. These batteries are collected for recycling after being widely used in fields such as electric vehicles, energy storage systems, and consumer electronics. The procurement of waste may be carried out through battery manufacturers, consumer recycling programs, or industrial waste processing facilities. The inclusion of these end-of-life batteries in the recovery process enables the reintegration of the valuable metals they contain into the economy, while also allowing for the effective management of hazardous components that have the potential to cause environmental harm.

[0023] - Mechanical processing and shredding of the waste to obtain black mass

[0024] As a result of mechanically processing and shredding the waste obtained in the previous process step, an intermediate product referred to as black mass is obtained. The waste isphysically broken and ground, and then supporting components such as plastic, paper, and metal are separated.

[0025] The obtained black mass is an intermediate product in powder or granular form containing valuable metals (nickel, manganese, cobalt, and lithium) together with impurities such as copper, aluminum, and iron. The black mass constitutes a fundamental stage of lithium-ion battery recycling and serves as a starting point for processes aimed at recovering the strategic metals it contains. The processing of this intermediate product provides both environmental sustainability and economic benefit in recovery processes.

[0026] - Subjecting the obtained black mass to leaching processes

[0027] In this invention, leaching processes are carried out to transfer the valuable metals into solution from the black mass obtained in the previous process step. Leaching is based on converting the metal oxides present in the black mass obtained from waste NMC batteries into ionic form using an appropriate solution.

[0028] In this invention, at least one of sulfuric acid, nitric acid, or hydrochloric acid is preferred as the solution for the leaching processes. These solutions are used because they effectively enable the dissolution of different metal species present in the black mass.

[0029] The mentioned black mass is added to the solution during the leaching process. This solution, together with the selected pH values, performs two main functions. The first function is to enable the valuable metals present in the black mass to be converted from oxide form into ionic form and thus to enter the solution. This conversion allows the valuable metals to be transferred into the liquid phase and prepared for recovery processes. The second function is the precipitation and separation of impurities present in the black mass within the solution. This process increases the purity of the valuable metals and improves the efficiency of the recovery processes by removing the impurities from the solution.

[0030] The transfer of the mentioned valuable metals into the solution and the precipitation of a certain portion of the impurities are carried out at controlled pH levels. The present inventors have determined that having the pH value of the solution to be used within the range of 1 to 4 provides technical solutions and advantages.If preferred, at least one antioxidant is added to this leaching solution. This oxidizing additive is added in order to increase the redox potential of the chemical reactions, to enable the dissolution of metal oxides and increase reaction rates, and to control impurities. In the most preferred embodiment, hydrogen peroxide is used as the oxidant. In a preferred embodiment, hydrogen peroxide is added to the leaching solution in an amount ranging from 2% to 20% by weight.

[0031] The leaching solution used in this invention comprises acidic solutions having a molar concentration in the range of 0.1 to 10 M.

[0032] The amount of black mass added to this solution varies such that the black mass-to-liquid weight ratio is in the range of 1 :5 to 1 :500.

[0033] In the method according to the invention, the leaching process as a process step is carried out at a temperature in the range of 25 to 100 °C.

[0034] By adhering to these parameters, the leaching process can be carried out for a duration in the range of 0.1 to 24 hours.

[0035] In order to shorten the reaction times at the specified temperature values, it is possible to stir the solution at a speed in the range of 100 to 3000 rpm. This stirring process increases the reaction surface area by ensuring homogeneous distribution of the reactants within the solution and enhances the rate of chemical reactions.

[0036] Within the leaching solution, iron present in the black mass is precipitated in the form of iron oxide at a pH range of 1 to 4.

[0037] Within the leaching solution, copper present in the black mass is precipitated in sulfide form at a pH range of 1 to 4.

[0038] Aluminum, on the other hand, can be precipitated as aluminum oxide in the pH range of 3 to 7. When the pH range of the leaching solution is 1 to 4, it is ensured that a portion of the aluminum is retained in the solution as a precipitate from the black mass in the form of aluminum oxide.

[0039] The iron oxide, aluminum oxide, and copper sulfate separated as precipitates can be reused as raw materials in various technical fields.For the present invention, the process continues with the solution into which the ionic forms of the valuable metals, which are critical to the invention, have passed.

[0040] - Performing filtration and separation processes

[0041] Filtration and separation processes constitute a critical step that ensures the separation of the metals transferred into the solution after the leaching process from the undissolved solid wastes. In these processes, materials that do not separate from the black mass and do not dissolve in the leaching solution are filtered out and removed from the system.

[0042] The filtration process increases the purity of the solution and prepares a suitable medium for subsequent precipitation and purification processes. The metal ions remaining in the solution are subjected to precipitation processes at specific pH values, thereby enabling the recovery of valuable metals. On the other hand, the solid wastes separated from the solution are disposed of or, where appropriate, directed to recycling processes.

[0043] Filtration and separation are carried out by filtration processes. To perform this process, at least one of a paper filter, membrane filter, metal filter, sand filter, vacuum filter, or pressure filter group may be preferred. After the filtration process, if preferred, a centrifugation method may also be added to the process.

[0044] - pH adjustment and precipitation processes of the solution subjected to filtration and separation

[0045] In this process step, it is aimed to separate certain impurities and valuable metals present in the solution obtained by the leaching process. In this step, the valuable metals are separated from the leaching solution as precipitates.

[0046] To carry out this process, pH adjustments suitable for the precipitation of the valuable metals present in the solution are performed. These pH adjustments initiate the separation of metal ions within the solution and ensure the controlled precipitation of the valuable metals. The pH value of the mixture obtained from the leaching solution is gradually and controllably increased by adding a solution having a high pH value.

[0047] Accordingly, by adding at least one high-pH solution to the leaching solution, achieving a pH in the range of 7 to 10 enables the recovery of the valuable metals present in the post-leaching solution, namely nickel, manganese, and cobalt ions, by precipitating them in hydroxide form (Ni(OH)2, Mn(OH)2, Co(OH)2).

[0048] As a pH-increasing agent in this invention, at least one of sodium hydroxide, ammonia, or sodium carbonate is preferred.

[0049] In a preferred embodiment, at least one of thioacetamide or sodium sulfide may be preferred for precipitating metals such as copper in sulfide form.

[0050] In the invention, as the pH value of the leaching solution is increased, lithium carbonates present therein are also obtained in the form of a precipitate. By increasing the pH value of the leaching solution to values in the range of 10 to 12, the recovery of lithium carbonate from the solution is achieved. This pH range enables the effective separation of lithium from other metals and its recovery at high purity.

[0051] As a result of these processes, the precipitated hydroxides of the valuable metals and the lithium carbonates are separately removed from the reaction media in the form of precipitates. The precipitated solids are separated from the solution. This process is generally carried out by methods such as filtration or centrifugation. The solids are filtered to separate them from the liquid and are prepared for further processing. The separated solid products are purified and sent to subsequent stages.

[0052] - Calcination of the precipitated valuable metal hydroxides and lithium carbonates

[0053] The product intended to be obtained in this invention is a high-purity and homogeneous NMC cathode material obtained by combining valuable metals and lithium. This cathode material provides a structure with high energy density and stability for use in nextgeneration lithium-ion batteries. Calcination processes also enable the removal of impurities and the enhancement of the stability of chemical compounds.

[0054] The hydroxides of the valuable metals and the lithium carbonate obtained from the black mass are heated to high temperatures to be converted into mixed metal oxides. During calcination, the metal hydroxides undergo thermal decomposition and transform into oxide form, and lithium carbonate reacts with the other metal oxides to form a mixed oxide structure.The temperature of the calcination processes mentioned is in the range of 800 to 1300 °C. This range is optimized to ensure complete reaction of the mentioned components and the production of a high-quality cathode material.

[0055] The duration of the calcination process is in the range of 4 to 24 hours. This duration is critical to ensure homogeneous reaction of the raw materials and the stability of the structure.

[0056] The specified temperature values and cooling processes are carried out slowly and in a controlled manner within the specified time intervals. This ensures that the crystal structure of the target products is formed without being damaged.

[0057] The calcination processes are carried out in environments provided with oxygen flow or in controlled inert atmospheres.

[0058] By applying the calcination processes, the nickel (Ni), manganese (Mn), and cobalt (Co) hydroxides and lithium carbonate (Li2CO3) obtained as a result of the leaching and precipitation processes are calcined at high temperature (800-1300 °C) and converted into mixed metal oxides in the form of a nickel-manganese-cobalt (NMC) cathode material. By applying this process step, the chemical structure of the metal hydroxides is stabilized, and by reacting with lithium carbonate, a high-purity, homogeneous, and thermally stable NMC structure is obtained.

[0059] For the production of NMC, lithium carbonate is added to the mixture in an amount in the range of 0.8 to 1.2 mol. The other hydroxides (nickel, manganese, and cobalt) are each added in an amount in the range of 0.3 to 0.95 mol.

[0060] With the method characterized in the invention, strategic metals such as nickel (Ni), manganese (Mn), cobalt (Co), and lithium (Li) are recovered from waste NMC batteries at high purity. These metals are fundamental components in energy storage systems, particularly in the production of lithium-ion batteries. In this way, the conservation of natural resources is ensured, while the reintegration of valuable metals into the circular economy is made possible.

[0061] With the method characterized in the invention, impurities such as iron, copper, and aluminum present in the intermediate black mass are effectively separated by selectiveprecipitation methods. In this way, the purity of the recovered valuable metals is increased, while the efficiency of the recycling process is enhanced.

[0062] The method characterized in the invention provides an environmentally sensitive recycling approach with low chemical consumption and low energy requirements. While preventing waste from causing harm to the environment, it adopts an approach that minimizes environmental pollution. In addition, the reuse of the recovered metals contributes to environmental sustainability by reducing the amount of waste.

[0063] The method characterized in the invention makes it possible to recover lithium from waste batteries in the form of lithium carbonate. The situation encountered in the prior art, in which lithium cannot be recovered with high efficiency, can be overcome by the method characterized in the invention.

[0064] The scope of protection of the invention is defined in the claims attached hereto and cannot be limited in any way to the examples described in this detailed description for illustrative purposes. It is evident that a person skilled in the art may develop similar embodiments in light of the above without departing from the main concept of the invention.

Claims

CLAIMS1. The invention is a method in which valuable metals are recovered from nickel- manganese-cobalt-containing waste batteries and these recovered valuable metals are used as raw materials in the production of cathode materials, characterized in that it comprises the following process steps:- obtaining black mass by crushing the waste batteries, reducing the particle size, and cleaning,- subjecting the obtained black mass to leaching processes and obtaining a leaching solution,taking, from said leaching solution, iron as iron oxide, copper as copper sulfide, and aluminum as aluminum oxide as precipitates, which constitute impurities for the black mass,wherein, in said leaching processes, at least one acid selected from the group consisting of sulfuric acid, hydrochloric acid, or nitric acid is used,wherein the pH value range of the leaching processes is in the range of 1 to 4,taking, from said leaching solution, iron as iron oxide, copper as copper sulfide, and aluminum as aluminum oxide as precipitates, which constitute impurities for the black mass,- performing filtration and separation processes to separate undissolved solid substances from the leaching solution obtained by the leaching process,- performing pH-controlled precipitation processes to obtain hydroxide precipitates of the valuable metals and lithium carbonate precipitates from the leaching solution from which the undissolved solid substances have been separated,wherein, in said pH-controlled precipitation processes, at least one selected from the group consisting of sodium hydroxide, ammonia, or sodium carbonate is used as a pH adjuster,wherein, when the pH value of said solution is in the range of 7 to 10, hydroxide precipitates of the valuable metals nickel, manganese, and cobalt are obtained from the solution,wherein, when the pH value of said solution is in the range of 10 to 12, a lithium carbonate precipitate, which is another valuable metal, is obtained from the solution,- obtaining an NMC cathode material by subjecting the obtained precipitates together to calcination processes,wherein the calcination temperature mentioned is in the range of 800 to 1300 °C.

2. The method according to claim 1 , characterized in that the fragmentation processes are carried out mechanically by at least one selected from the group consisting of grinding, crushing, or cutting.

3. The method according to one of the preceding claims, characterized in that the acidic solutions used in the leaching processes have a concentration in the range of 0.1 to 10 M.

4. The method according to one of the preceding claims, characterized in that at least one selected from the group consisting of a paper filter, membrane filter, metal filter, sand filter, vacuum filter, or pressure filter is used for said filtration and separation processes.

5. The method according to claim 4, characterized in that centrifugation processes are carried out after the filtration process.

6. The method according to one of the preceding claims, characterized in that the leaching processes are carried out at a temperature in the range of 25 to 100 °C.

7. The method according to one of the preceding claims, characterized in that the leaching processes are carried out for a duration in the range of 0.1 to 24 hours.

8. The method according to one of the preceding claims, characterized in that the leaching processes are carried out with a black mass-to-liquid weight ratio in the range of 1 :5 to 1 :500.

9. The method according to one of the preceding claims, characterized in that hydrogen peroxide is added to the leaching solution in an amount in the range of 2% to 20% by weight.

10. The method according to one of the preceding claims, characterized in that the leaching solution is subjected to stirring at a speed in the range of 100 to 3000 rpm.

11. The method according to one of the preceding claims, characterized in that, for the production of the NMC cathode material, lithium carbonate is present in the mixture in an amount in the range of 0.8 to 1.2 mol, and each of the nickel, manganese, and cobalt hydroxides is present in an amount in the range of 0.3 to 0.95 mol.

12. The method according to one of the preceding claims, characterized in that the calcination duration is in the range of 4 to 24 hours.