Valuable metal recovery composition

Abstract

The present invention provides a valuable metal recovery composition comprising a lithium-based compound, wherein the lithium-based compound comprises Al, the content of the Al is 10 to 60 wt% with respect to 100 wt% of the lithium-based compound, and the valuable metal recovery composition has a flake shape.

Description

Valuable metal recovery composition

[0001] The present invention relates to waste batteries, and more specifically to a composition for recovering valuable metals recovered from waste battery recycling, a method for recovering the same, reactants, crushed valuable metals, and a method for recovering valuable metals.

[0002] The present invention claims priority based on Korean Patent Application No. 10-2024-0191907 filed on December 19, 2024, the entire contents of said application incorporated herein by reference.

[0003] As global demand for electric vehicles (EVs) intensifies, the issue of disposing of waste batteries generated from these vehicles is emerging as a social concern. Lithium-ion batteries, which serve as the primary raw material for these waste batteries, contain organic solvents, explosive substances, and heavy metals such as Ni, Co, Mn, Fe, and P. However, Ni, Co, Mn, Fe, P, and Li are valuable metals with high scarcity value, making the recovery and recycling processes for lithium-ion batteries after disposal a critical area of ​​research.

[0004] Specifically, the lithium secondary battery comprises copper and aluminum used as current collectors, oxides containing Li, Ni, Co, Mn, Fe, and P constituting the cathode material, and graphite and Si used as the anode material, and includes a separator that separates the cathode material and the anode material, and an electrolyte injected into the separator. The solvent used as the solvent and salt constituting the electrolyte mainly consists of a mixture of carbonate organic materials such as ethylene carbonate and propylene carbonate.

[0005] To utilize the aforementioned waste batteries, interest is emerging in waste battery recycling processes that involve crushing the waste batteries to produce intermediate materials such as shredded waste batteries or black powder, followed by subsequent processing to recover valuable metals. Specifically, the major components of waste batteries consist of expensive valuable metal elements such as Ni, Co, Mn, Li, Fe, and P.

[0006] The above waste battery is, for example, a secondary battery that has reached the end of its lifespan after being used for a cycle of 5 to 10 years, and recycling the main components of the waste battery is absolutely necessary from an environmental and cost perspective. The above waste battery undergoes conventional crushing, grinding, or sorting processes to produce a mixture of cathode and anode materials in the form of black powder, which is an intermediate product.

[0007] Methods for recovering valuable metals from the black powder are broadly classified into wet and dry processes. The wet process involves using acid to dissolve components within the raw material, primarily using sulfuric acid, and dissolving metal components within the raw material through a leaching process. Key process parameters include pH and temperature, and the particle size of the raw material also has a significant impact.

[0008] The process involves selectively extracting specific components from the leached valuable metals, a process called solvent extraction. The solvent extraction process utilizes an extractant capable of selectively extracting components based on pH. The selectively extracted components are then subjected to a final crystallization process to produce high-purity metal sulfates, which are subsequently sold as products. During this series of processes, wastewater and waste coal dust are generated as waste at the water discharge facility.

[0009] In addition, the above dry process involves heat treatment of the black mass at high temperatures to form valuable metals in the form of alloys rather than oxides. For example, an alloy of nickel and cobalt is formed through heat treatment at high temperatures. The alloy obtained in this way is also recycled as a raw material for batteries through a wet process, such as leaching or extraction. Key factors in this process include pH, temperature, and the type of oxidizer. In the case of alloys produced through the dry process, the alloy particle size can also act as a major factor in the efficiency of the wet process.

[0010] Generally, as the particle size of the raw material increases, the efficiency of the leaching process decreases, so it is important to obtain fine particles; however, since the size and shape of the raw material affect the screening process, it is necessary to control the optimal particle size and shape.

[0011] The objective of the present invention is to provide a valuable metal recovery composition capable of maximizing the efficiency of wet leaching and the recovery rate of lithium in the screening process.

[0012] A valuable metal recovery composition according to one embodiment of the present invention comprises a lithium-based compound, wherein the lithium-based compound comprises Al, and the content of Al is 10 to 60 wt% with respect to 100 wt% of the lithium-based compound, and has a flake shape.

[0013] The above composition may satisfy at least one of the following formulas 1 to 4.

[0014] [Equation 1]

[0015] 2 ≤ [Al] / [Li] ≤ 20

[0016] [Equation 2]

[0017] 0 < [Mn] / [Li] ≤ 4

[0018] [Equation 3]

[0019] 0 < [Co] / [Li] ≤ 2

[0020] [Equation 4]

[0021] 0 < [Ni] / [Li] ≤ 5

[0022] (In the above Formulas 1 to 4, [Li], [Al], [Mn], [Co], and [Ni] each represent the wt% of Li, Al, Mn, Co, and Ni based on 100 wt% of the composition.)

[0023] The above lithium-based compound may include at least one of LiAlO2, Li5AlO4, and LiAl5O8.

[0024] The above composition includes a nickel-based alloy, and the nickel-based alloy may exist on the surface of the lithium-based alloy.

[0025] The above nickel-based alloy may exist in a partially molten state in at least some regions of the above lithium-based compound.

[0026] The above nickel-based alloy may exist at 15% based on 100% of the surface of the above lithium-based compound.

[0027] The particle size of the above nickel-based alloy may be 250 μm or less.

[0028] The flake shape may have at least one angle where the two outer lines of the composition meet at 90° or less.

[0029] A valuable metal recovery composition according to one embodiment of the present invention includes a reactant having a flake shape with low content of Ni, Mn, and Co and high content of Li and Al, thereby maximizing the efficiency of wet leaching and the efficiency in the screening process.

[0030] Figure 1 is a scanning electron microscopy (SEM) image of an example.

[0031] Figure 2 is a SEM-EDS (scanning electron microscopy-energy dispersive spectroscopy) image of an example.

[0032] Figure 3 is a digital image of Comparative Example 1.

[0033] Figure 4 is a digital image of Comparative Example 2.

[0034] Figure 5 is a SEM-EDS (scanning electron microscopy-energy dispersive spectroscopy) image of Comparative Example 2.

[0035] Figure 6 is a SEM-EDS (scanning electron microscopy-energy dispersive spectroscopy) image of Comparative Example 3.

[0036] Terms such as first, second, and third are used to describe various parts, components, regions, layers, and / or sections, but are not limited thereto. These terms are used solely to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Accordingly, the first part, component, region, layer, or section described below may be referred to as the second part, component, region, layer, or section without departing from the scope of the present invention.

[0037] The technical terms used herein are for the reference of specific embodiments only and are not intended to limit the invention. The singular forms used herein include plural forms unless phrases clearly indicate otherwise. As used in the specification, the meaning of "comprising" specifies certain characteristics, areas, integers, steps, actions, elements, and / or components, and does not exclude the presence or addition of other characteristics, areas, integers, steps, actions, elements, and / or components.

[0038] When it is stated that one part is "above" or "on" another part, it may be directly above or on the other part, or other parts may be involved in between. In contrast, when it is stated that one part is "directly above" another part, no other parts are interposed in between.

[0039] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as generally understood by those skilled in the art to which this invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with relevant technical literature and the present disclosure, and are not interpreted in an ideal or highly formal sense unless otherwise defined.

[0040] Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and are not intended to limit the present invention, and the present invention is defined only by the scope of the claims set forth below.

[0041] According to one embodiment of the present invention, a valuable metal recovery composition comprises a reactant having a flake shape, and may be formed by performing a high-temperature reduction heat treatment process on a battery or a crushed battery material obtained by crushing said battery. Specifically, the valuable metal recovery composition may comprise a plurality of the reactants having the flake shape.

[0042] The reactant having the flake shape described above may partially maintain the shape of the current collector within the battery or battery crush by performing the high-temperature reduction heat treatment process on the battery or battery crush at the temperature at which lithium begins to be reduced. Since the valuable metal recovery composition includes the reactant having the flake shape, separation from graphite during particle size and magnetic separation in the subsequent separation process is more advantageous, which has excellent benefits for improving the recovery rate of valuable metals. Specifically, if the reactant does not have a flake shape, fine metal particles are formed on the surface of the graphite; consequently, it is difficult to physically separate the metal particles from the graphite surface, and there is a problem in that separation is difficult even by methods such as particle size separation because the size difference with the graphite is not significant. Furthermore, if the metal particles are attached to the graphite surface, they become magnetic, which causes a problem of lowering the recovery rate of valuable metals in the subsequent magnetic separation stage.

[0043] The flake shape mentioned above may mean an irregular shape. Specifically, the irregular shape may mean a shape including a pointed region.

[0044] In one embodiment, the flake shape may be characterized in that at least one of the angles where the two outer lines of the reactant meet is 90° or less.

[0045] For example, when a plurality of outlines are drawn on the outer surface of the reactant for an SEM image of the reactant, the reactant may be characterized by having a plurality of regions in which the angle at which two of the outlines meet is 90° or less. In one embodiment, the reactant having a flake shape may include a base material and an alloy disposed on at least a portion of the surface of the base material. Specifically, the reactant having a flake shape may be disposed on at least a portion of the surface of the base material by partially melting the alloy on the base material.

[0046] In one embodiment, the alloy may refer to a nickel-based alloy. The alloy has nickel as its main component and, in addition to nickel, may include cobalt, manganese, copper, iron, or a combination thereof.

[0047] In one embodiment, the base material may refer to a lithium-based compound. Specifically, the base material may include at least one of a lithium compound and graphite. Specifically, the base material may be formed by high-temperature heat treatment of a battery or battery crushed material, and formed by reducing at least a portion of the battery or battery crushed material, such that, for example, a component such as a current collector may be arranged while maintaining a partial shape.

[0048] Specifically, the base material may include a compound in which aluminum, which is a major component of the current collector, forms an oxide with lithium, and may also include graphite constituting the negative electrode material. By including at least one of the lithium compound and graphite in the base material, the components excluding the valuable metal can be easily separated when selecting the valuable metal in a subsequent process, thereby increasing the recovery rate of the valuable metal. In this case, the lithium-based compound may include LiAlO2, Li5AlO4, LiAl5O8, Li2CO3, and LiF, etc.

[0049] In one embodiment, the alloy may be a nickel-based alloy. Specifically, the alloy may be formed by partially melting a metallic material constituting the positive electrode active material during a high-temperature heat treatment of a battery or battery crushed material and coating it onto the base material. The alloy may, for example, include metallic materials such as nickel, cobalt, manganese, copper, or iron as the material constituting the positive electrode active material. Specifically, the alloy may be formed by partially melting and alloying a metal such as nickel or copper. By partially melting and placing the alloy on at least a portion of the base material, the magnetic alloy can be easily separated during a subsequent sorting process, thereby increasing the recovery rate of valuable metals.

[0050] In one embodiment, the lithium-based compound comprises aluminum (Al), and the content of the aluminum may be 5 to 60 wt% with respect to 100 wt% of the lithium-based compound. In one embodiment, the lithium-based compound may comprise at least one of LiAlO2, Li5AlO4, and LiAl5O8.

[0051] Specifically, the aluminum content is 5 to 57 wt%, 5 to 54 wt%, 5 to 51 wt%, 5 to 48 wt%, 5 to 45 wt%, 5 to 42 wt%, 5 to 39 wt%, 5 to 36 wt%, 5 to 33 wt%, 8 to 60 wt%, 8 to 57 wt%, 8 to 54 wt%, 8 to 51 wt%, 8 to 48 wt%, 8 to 45 wt%, 8 to 42 wt%, 8 to 39 wt%, 8 to 36 wt%, 8 to 33 wt%, 11 to 60 wt%, 11 to 57 wt%, 11 to 54 wt%, 11 to 51 wt%, 11 to 48 wt%, 11 to 45 wt%, 11 to 42 wt%, 11 to 39 wt%, 11 to 36 wt%, 11 to 33 wt%, 14 to 60 wt%, 14 to 57 wt%, 14 to 54 wt%, 14 to 51 wt%, 14 to 48 wt%, 14 to 45 wt%, 14 to 42 wt%, 14 to 39 wt%, 14 to 36 wt%, 14 to 33 wt%, 17 to 60 wt%, 17 to 57 wt%, 17 to 54 wt%, 17 to 51 wt%, 17 to 48 wt%, 17 to 45 wt%, 17 to 42 It may be wt%, 17 to 39 wt%, 17 to 36 wt%, 17 to 33 wt%, 21 to 60 wt%, 21 to 57 wt%, 21 to 54 wt%, 21 to 51 wt%, 21 to 48 wt%, 21 to 45 wt%, 21 to 42 wt%, 21 to 39 wt%, 21 to 36 wt%, and 21 to 33 wt%.

[0052] By satisfying the aforementioned range of aluminum content, at least one of high-purity compounds such as LiAlO2, Li5AlO4, and LiAl5O8 can be obtained without any additional processes when selecting lithium-based compounds in the subsequent process. Furthermore, in the lithium extraction process, there is an advantage of a high lithium recovery rate due to the high content of at least one of LiAlO2, Li5AlO4, and LiAl5O8. If the aluminum content exceeds the upper limit of the aforementioned range, numerous compounds such as Al2O3 may be formed in addition to the aforementioned lithium aluminum oxide, which may hinder selection and leaching as impurities. Additionally, if it exceeds the lower limit of the aforementioned range, compounds such as LiF and Li2CO3 are formed. Since these compounds have higher solubility in water compared to lithium aluminum oxide, problems may arise, such as the inability to apply water-based subsequent processes or the requirement for additional processes during selection.

[0053] In one embodiment, the reactant may satisfy at least one of the following formulas 1 to 4.

[0054] [Equation 1]

[0055] 2 ≤ [Al] / [Li] ≤ 20

[0056] [Equation 2]

[0057] 0 < [Mn] / [Li] ≤ 4

[0058] [Equation 3]

[0059] 0 < [Co] / [Li] ≤ 2

[0060] [Equation 4]

[0061] 0 < [Ni] / [Li] ≤ 5

[0062] In the above formulas 1 to 4, [Li], [Al], [Mn], [Co], and [Ni] each represent the wt% of Li, Al, Mn, Co, and Ni based on 100 wt% of the composition.

[0063] The above Equation 1 represents the ratio of aluminum content to lithium in the reactant, and may be an indicator of the efficiency of recovering valuable metals. Specifically, the above Formula 1 comprises 2 to 20, 2 to 18, 2 to 16, 2 to 14, 2 to 12, 2 to 10, 2 to 8, 2 to 6, 2.5 to 20, 2.5 to 18, 2.5 to 16, 2.5 to 14, 2.5 to 12, 2.5 to 10, 2.5 to 8, 2.5 to 6, 3 to 20, 3 to 18, 3 to 16, 3 to 14, 3 to 12, 3 to 10, 3 to 8, 3 to 6, 3.5 to 20, 3.5 to 18, 3.5 to 16, 3.5 to 14, 3.5 to 12, 3.5 to 10, 3.5 to 8, It may be 3.5 to 6, 4 to 20, 4 to 18, 4 to 16, 4 to 14, 4 to 12, 4 to 10, 4 to 8, or 4 to 6.

[0064] By satisfying the aforementioned range of aluminum content, at least one of high-purity compounds such as LiAlO2, Li5AlO4, and LiAl5O8 can be obtained without any additional processes when selecting lithium-based compounds in the subsequent process. Furthermore, in the lithium extraction process, there is an advantage of a high lithium recovery rate due to the high content of at least one of LiAlO2, Li5AlO4, and LiAl5O8. If the aluminum content exceeds the upper limit of the aforementioned range, numerous compounds such as Al2O3 may be formed in addition to the aforementioned lithium aluminum oxide, which may hinder selection and leaching as impurities. Additionally, if it exceeds the lower limit of the aforementioned range, compounds such as LiF and Li2CO3 are formed. Since these compounds have higher solubility in water compared to lithium aluminum oxide, problems may arise, such as the inability to apply water-based subsequent processes or the requirement for additional processes during selection.

[0065] Formulas 2 to 4 above each represent the content ratio of manganese, cobalt, and nickel to lithium in the reactants, and may serve as an indicator of the efficiency of recovering valuable metals.

[0066] Specifically, the above formula 2 may be greater than 0 and less than or equal to 4, greater than 0 and less than or equal to 3.5, greater than 0 and less than or equal to 3, greater than 0 and less than or equal to 2.5, greater than 0 and less than or equal to 2, greater than 0 and less than or equal to 1.5, greater than 0 and less than or equal to 1, greater than 0 and less than or equal to 0.8, and greater than 0 and less than or equal to 0.6.

[0067] Specifically, the above formula 3 may be greater than 0 and less than or equal to 2, greater than 0 and less than or equal to 1.5, greater than 0 and less than or equal to 1, greater than 0 and less than or equal to 0.8, greater than 0 and less than or equal to 0.6, greater than 0 and less than or equal to 0.4, and greater than 0 and less than or equal to 0.3.

[0068] Specifically, the above formula 4 may be greater than 0 to 5 or less, greater than 0 to 4.5 or less, greater than 0 to 4 or less, greater than 0 to 3.5 or less, greater than 0 to 3 or less, greater than 0 to 2.5 or less, greater than 0 to 2 or less, greater than 0 to 1.5 or less, greater than 0 to 1 or less, greater than 0 to 0.8 or less, greater than 0 to 0.6 or less.

[0069] By satisfying at least one of the above Equations 2 to 4 within the aforementioned range, the leaching efficiency of lithium can be improved when extracting lithium in a subsequent process by including a small amount of manganese, cobalt, or nickel in the reactant. If Equations 2 to 4 fall outside the upper limit of the aforementioned range, the above advantages cannot be achieved because manganese, cobalt, or nickel is contained in excess. Furthermore, theoretically, Equations 2 to 4 cannot reach zero, and since a lower content of manganese, cobalt, and nickel is more advantageous for lithium extraction, no particular restriction is placed on the lower limit.

[0070] In one embodiment, the particle size of the reactant may satisfy a range of 100 to 1000 μm. Specifically, the reactant may include i) a reactant having a first particle size of 100 to 150 μm, ii) a reactant having a second particle size of 150 to 250 μm, iii) a reactant having a third particle size of 250 to 500 μm, and iv) a reactant having a fourth particle size of 500 to 1000 μm. The particle size of the reactant may refer to an average particle size (D50).

[0071] In one embodiment, based on 100% of the reactants, the reactant having the first particle size may be included in an amount of 8 to 19%, the reactant having the second particle size in an amount of 12 to 25%, the reactant having the third particle size in an amount of 30 to 38%, and the reactant having the fourth particle size in an amount of remainder. The % may be based on volume.

[0072] When the particle size of the aforementioned reactant is formed as fine particles of less than 100 μm, there is a problem in that separation from graphite is not easy. However, when the particle size of the aforementioned reactant is formed as large as 100 μm or more, the particle size of the metal droplet formed on the flake is much finer than that of the flake, so there is an advantage of high leaching efficiency.

[0073] Specifically, satisfying the aforementioned range for the particle size of the reactant provides the advantage of facilitating leaching and screening processes in subsequent steps. If the particle size of the reactant is excessively coarse, the amount of valuable magnetic metal within the flake is relatively small, leading to a problem where the metal recovery rate decreases even if magnetism is present. If the particle size of the reactant is excessively small, the structure of the crushed material collapses, forming fine particles akin to dust, resulting in inferior screening and leaching efficiency for magnetic separation.

[0074] In one embodiment, the particle size of the alloy may be 250 μm or less. Specifically, the particle size of the alloy may satisfy a range of 1 to 180 μm. By satisfying the aforementioned range for the particle size of the alloy, there is an advantage of excellent leaching and screening efficiency. If the particle size of the alloy is excessively coarse, there is a problem in that the leaching of alloy particles is not easy during leaching.

[0075] In one embodiment, the ratio of the alloy may be 15% or less based on 100% of the surface of the base material. Specifically, based on 100% of the surface of the base material, the ratio of the alloy partially melted and coated on the surface of the base material may be 13% or less, 10% or less, 7% or less, or 5% or less. By forming the fine alloy on the surface of the base material (flake) at the aforementioned ratios, there is an advantage of high lithium leaching efficiency. The ratio of the alloy may refer to the ratio of either the upper surface or the lower surface of the base material.

[0076] In one embodiment, the proportion of the alloy on the surface with a higher proportion of the alloy among the upper or lower surfaces of the base material may be 70% or more based on 100% of the surface of the base material. Specifically, the proportion of the alloy may be 70% to 95%, specifically 75% to 95%.

[0077] In one embodiment, the shape of the partially molten alloy may have a spherical shape. Specifically, the shape of the alloy is formed by melting the oxide anode material after reduction, and at this time, it may have a spherical shape with the lowest surface energy. Specifically, the shape of the alloy may manifest as a spherical shape with the lowest surface area.

[0078] According to another embodiment of the present invention, a method for recovering valuable metals comprises the steps of preparing a battery and performing high-temperature heat treatment on the battery or on a battery crushed from the battery. As the method for recovering valuable metals according to the present invention is performed at a temperature at which at least a portion of the battery or the battery crush begins to be reduced, a valuable metal recovery composition may be formed comprising a reactant having a flake shape as described above, wherein the alloy is partially melted and disposed on at least a portion of the base material and the surface of the base material. A detailed description of the valuable metal recovery composition may refer to the foregoing to the extent that it is not contradictory.

[0079] In the step of preparing the battery, the battery may include end-of-life batteries, cathode materials such as scrap, jelly rolls, and slurries constituting the waste battery, defective products generated during the manufacturing process, residues within the manufacturing process, and generated debris, for example, waste materials within the manufacturing process of a lithium-ion battery. In this way, the waste battery can be prepared as the battery to recycle the battery.

[0080] In one embodiment, the step of preparing the battery may include a pretreatment step for the battery. Specifically, by including the pretreatment step, explosive substances such as the electrolyte within the battery can be removed to increase safety in subsequent processes and maximize the efficiency of recovery and separation of valuable metals.

[0081] In one embodiment, the step of pre-treating the battery may include the step of discharging the battery. The step of discharging the battery may pre-treat the battery by various methods, such as water discharge or electric discharge, as a non-limiting example.

[0082] When the step of discharging the battery is performed by electric discharge, the voltage of the battery can be reduced to control the voltage of the cell within the battery. For example, the voltage of the battery can be controlled to a voltage of 0 to 4.2 V relative to the cell within the battery.

[0083] The step of treating the battery at a low temperature below a minimum temperature according to the voltage of the battery may be a step of freezing and stabilizing the electrolyte contained within the battery. By treating the battery below a minimum temperature, it is possible to prevent a fire caused by hazardous materials, such as the electrolyte, when the battery is crushed.

[0084] In one embodiment, the low-temperature treatment step may be a step of treating the battery at 10°C or lower. Specifically, when the voltage of the battery is 1.0 V or lower, the low-temperature treatment step may be performed on the battery at a temperature of 0°C or lower. More specifically, when the voltage of the battery is 1.5 to 2.0 V, the battery may be low-temperature treated at a temperature of -15°C or lower. More specifically, when the voltage of the battery is approximately 2.5 V, the battery may be low-temperature treated at a temperature of -30°C or lower. More specifically, when the voltage of the battery is 3 to 3.5 V, the battery may be low-temperature treated at a temperature of -50°C or lower.

[0085] In this way, the battery has the advantage of being able to be safely crushed in the crushing process by performing low-temperature treatment within a specific temperature range according to the cell reference voltage of the battery.

[0086] As the step of performing low-temperature treatment on the battery within the above temperature range is performed, the voltage remaining in minutely within the battery, for example, about 2 V to 3 V, is reduced to near 0 V. Consequently, even if a short circuit occurs where the positive and negative electrodes come into direct contact, no battery reaction occurs, so the battery temperature does not increase, and thus no gas generation or combustion of the electrolyte occurs. Furthermore, since the electrolyte is in a frozen state or a state where vaporization is suppressed, the mobility of lithium ions is very low, so the current conduction characteristics due to the movement of lithium ions can be significantly reduced, and since vaporization of the electrolyte does not occur, flammable gases such as ethylene, propylene, and hydrogen can not be generated.

[0087] If the above low-temperature treatment step is performed at a temperature higher than the above temperature range, the voltage remaining inside the battery does not drop to 0 V, which may cause a battery reaction due to a short circuit, and the electrolyte is not completely frozen, making it unsuitable. In this way, the battery treatment method includes a low-temperature treatment step before crushing a battery such as a lithium secondary battery, thereby preventing the risk of fire that may occur during the battery crushing process.

[0088] The step of crushing the frozen battery may refer to a process of applying impact or pressure to the battery so that a portion of the battery detaches from the battery. In one embodiment, the step of crushing the battery may refer to a process of grinding the battery, a process of cutting the battery, a process of compressing the battery, and any combination thereof. Specifically, the crushing step may include any process that destroys the battery to obtain small-sized crushed material.

[0089] In one embodiment, the step of crushing the battery may include all processes of compressing the frozen battery or destroying the battery by applying an external force such as shear force or tensile force. The step of crushing the battery may be carried out, for example, using a crusher.

[0090] In one embodiment, the step of crushing the battery may be performed at least once. Specifically, the crushing step may be performed at least once, either continuously or discontinuously.

[0091] In one embodiment, the step of crushing the battery may be carried out under conditions of supplying an inert gas, carbon dioxide, nitrogen, water, or a combination thereof, or under vacuum conditions of 100 torr or less. For example, when the process of freezing the battery is carried out by cooling it in a temperature range of -60 to -20°C, or under the aforementioned conditions, the supply of oxygen can be suppressed to prevent the electrolyte from reacting with oxygen, thereby preventing an explosion caused by this, and the vaporization of the electrolyte can be suppressed so as not to generate flammable gases such as ethylene, propylene, or hydrogen.

[0092] In one embodiment, the step of crushing the battery may be performed such that the maximum size of the battery crushed material is 100 mm or less. Specifically, the size of the battery crushed material may be 50 mm or less. If the maximum size of the battery crushed material is 100 mm or more, the heat generated due to instability as the battery crushed material is crushed rises to a temperature range of 120 ℃, which is the average vaporization temperature of the electrolyte, and safety issues such as fire may occur.

[0093] In one embodiment, the battery fragment obtained through the step of crushing the battery may have a layered structure comprising a separator having a positive or negative electrode laminated on at least one surface. Specifically, the layered structure may include a configuration in which a positive or negative electrode is included on one surface or both surfaces of the separator based on the separator. More specifically, the number of layers of the layered structure may correspond to the number of separators. For example, the layered structure may include any one of a positive-separator-negative electrode, positive-separator, separator-positive electrode, separator-negative electrode, or negative-separator, and for example, a positive-separator-negative electrode-separator-positive-separator-negative electrode structure may have a three-layer layered structure. Specifically, the unit battery fragment may have a predetermined thickness in the thickness direction as at least one layer is laminated.

[0094] In one embodiment, the battery crusher may have a layered structure having a stacked structure of one or more to seven layers. Specifically, the layered structure may have a stacked structure of one or more to five layers. As the layered structure is stacked within the above range, the temperature rise of the crusher is minimized, and the heating time can be appropriately taken. If the layered structure is stacked thicker than the upper limit of the above range, the temperature rise increases excessively, and the heating time also increases, leading to a problem of causing a fire as combustion occurs.

[0095] In one embodiment, the size of the battery shredder may be 100 mm or less based on the major axis, which is the longest axis among the width, length, and height directions. Specifically, the size of the battery shredder may be 50 mm or less. By satisfying the aforementioned range for the size of the battery shredder, the possibility of fire occurring in subsequent processes can be reduced. If the size of the unit battery shredder is excessively large, there is a problem in that the temperature of the battery shredder itself rises to 100 ℃ or higher, increasing the likelihood of fire.

[0096] The step of high-temperature heat treatment of the battery or the battery fragments obtained by crushing the battery may be performed at a temperature at which at least a portion of the battery or the battery fragments begins to be reduced. Specifically, the heat treatment process may be performed at a temperature above which the positive electrode current collector is deformed, above which partial melting of the negative electrode current collector occurs, and below which lithium vaporizes and is lost.

[0097] In one embodiment, the temperature at which reduction begins may be 700 to 1,250 ℃. Specifically, the temperature may be performed in the range of 800 to 1,200 ℃, and more specifically, in the range of 900 to 1,100 ℃. As the high-temperature heat treatment step is performed in the aforementioned temperature range, a flake-shaped reactant can be easily formed in which the alloys constituting the anode active material partially melt while partially maintaining the shape of the current collector.

[0098] If the above temperature exceeds the upper limit of the aforementioned range, there is a problem in that the recovery rate of valuable metals decreases as lithium vaporizes and is lost. If the above temperature exceeds the lower limit of the aforementioned range, there is a problem in that the structure of the current collector is not deformed or the melting of the alloy is not performed smoothly.

[0099] In one embodiment, the high-temperature heat treatment step may be performed at a heating rate of 3°C or more per minute. Specifically, the heating rate may be 5°C or more per minute, more specifically 8 to 20°C. By performing the high-temperature heat treatment step within the heating rate range, there is an advantage that nucleation is easier than growth of the alloy.

[0100] If the aforementioned heating rate range exceeds the lower limit of the aforementioned range, smooth nucleation does not occur, and growth becomes relatively easy, leading to the problem of metal particles becoming coarse; the formation of such coarse alloys results in a decrease in the leaching rate in subsequent processes. If the aforementioned heating rate range exceeds the upper limit of the aforementioned range, the distortion of the current collector that holds the flake structure accelerates, forming relatively fine flakes and causing a problem of reduced separation efficiency from carbon.

[0101] In one embodiment, the high-temperature heat treatment step may be performed under conditions where the O2 volume fraction is less than 5%. In one embodiment, the high-temperature heat treatment step may be performed in an atmosphere containing an inert gas, and the inert gas may be performed under conditions where the volume fraction is less than 1%. The inert gas may include at least one of argon and nitrogen, and may be, for example, argon gas. By performing the high-temperature heat treatment step at the aforementioned oxygen volume fraction and inert gas volume fraction, the reduction process is easily performed, allowing for the effective recovery of valuable metals containing valuable metals as a component. Furthermore, if the oxygen content deviates from the aforementioned range, an excess amount of oxygen combines with the battery crushed material components within the reduction reaction to form carbon dioxide, which is gasified along with lithium, and consequently, there is a problem in that the recovery of lithium, a valuable metal, is not easy.

[0102] In one embodiment, the high-temperature heat treatment step can be performed in a temperature range satisfying the following Equation 1.

[0103] [Equation 5]

[0104] 700 ≤ T=(1000 + 250) × exp((0.0001 × [Cu]) + (-0.007 × [Al])) ≤ 1250

[0105] In the above Equation 4, [Al] is the content of Al (weight%) contained in the battery or battery crushed material, [Cu] is the content of Cu (weight%) contained in the crushed material, and the unit of the heat treatment condition is °C.

[0106] T in Equation 5 above may be an indicator regarding the formation of a reactant having a flake shape and the partial melting of the alloy. Since changes in the physical phenomena of the structure occur at relatively higher temperatures for copper (Cu) compared to aluminum (Al), the heat treatment temperature increases as the copper content increases. Conversely, since an increase in the aluminum content causes a relative decrease in the copper content, the heat treatment temperature must be lowered. Based on this, the relationship between the copper and aluminum content was derived as Equation 5. By satisfying the aforementioned range for Equation 5, a valuable metal recovery composition in which the alloy partially melts in a reactant having a flake shape can be easily realized, thereby increasing the leaching and separation efficiency of the valuable metal in subsequent processes.

[0107] At this time, in the above Equation 5, the aluminum content may be 1 wt% to 75 wt%, specifically 73 wt% or less, and the copper content may be 70 wt% or less. By satisfying the aforementioned ranges for the aluminum content and the copper content in the battery or battery crush, it may be possible to realize a composition in which the alloy is partially melted in a reactant having a flake shape.

[0108] If the above Equation 5 exceeds the upper limit of the aforementioned range, there is a problem in that the formation of flakes collapses excessively and becomes fine. If the above Equation 5 exceeds the lower limit of the aforementioned range, there is a problem in that the shape of the coarse crushed material is maintained and the alloy phase is not formed.

[0109]

[0110] Preferred embodiments and comparative examples of the present invention are described below. However, the following examples are merely preferred embodiments of the present invention, and the present invention is not limited to the following examples.

[0111]

[0112] Examples and Comparative Examples

[0113] Examples

[0114] (Battery preparation step) A cell-based 3.6 V battery was prepared for an NCM622 lithium-ion battery having approximately 4.2 V when the SOC is 100%. The battery was discharged to 0.5 V or lower within 2 hours by applying a current of 5 A to the initial battery. Afterward, the battery was subjected to cryogenic treatment at 60 ℃ for 24 hours.

[0115] (Step of shredding the battery) The battery was shredded using a 2-axis 2-stage shredder to a particle size range of 5 to 80 mm. The shredded battery material had a layered structure in which the positive electrode, negative electrode, and separator were stacked in sequence, and the layered structure was stacked in at least one layer, and the size of the battery shred was 100 mm or less. The size of the battery shred refers to the length based on the major axis among the width, length, and height of the battery shred. The shredding was completed within 5 minutes for the module and within 3 minutes for the cell.

[0116] (Step of reducing the battery to a high temperature) The battery was reduced to a high temperature in a high-temperature reduction furnace at a temperature at which at least a portion of the battery, for example, battery crushed material, begins to be reduced. Specifically, the battery was heated in a high-temperature reduction furnace at a heating rate of 3°C or more per minute, and after reaching 1,100°C, dry heat treatment was maintained for 2 hours. At this time, the heat treatment was carried out in an atmosphere of less than 5% O2 and less than 1% Ar. The aforementioned heat treatment conditions were performed at a temperature above which deformation is applied to the positive current collector, within a temperature range where some of the metal, such as copper, partially melts, and within a range where lithium is not lost through vaporization.

[0117]

[0118] Comparative Example 1 - Below lower temperature limit

[0119] In the step of reducing the battery to a high temperature, the heat treatment was performed at a low temperature of 700 ℃ or lower, except that the heat treatment was performed in the same manner as in the example.

[0120]

[0121] Comparative Example 2 - Exceeding Temperature Upper Limit

[0122] In the step of reducing the battery to a high temperature, the process was carried out in the same manner as the example, except that the heat treatment was performed at a high temperature of 1300 ℃.

[0123]

[0124] Comparative Example 3 - Exceeding the upper limit of the heating rate

[0125] The process was carried out in the same manner as the example, except that the heating rate in the step of reducing the battery to a high temperature was 30°C per minute.

[0126]

[0127] Evaluation example

[0128] Evaluation Example 1

[0129] Digital or SEM image observation and SEM-EDS (scanning electron microscopy-energy dispersive spectroscopy) analysis were performed on the examples and comparative examples.

[0130] Figure 1 is a scanning electron microscopy (SEM) image of an example, and Figure 2 is a scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) image of an example.

[0131] Looking at FIG. 1, it can be seen that the valuable metal recovery composition according to the embodiment has a flake shape, and there are multiple regions where the angle between two outer lines among the plurality of outer lines is 90° or less.

[0132] Figure 2 is an enlarged view of Figure 1, and the analysis results are as shown in Table 1 below. As shown in Table 1 below, it can be confirmed that the constituent elements of spectra 1 and 2 are very different. Spectrum 1 contains 61.5 wt% Ni and approximately 15 wt% of Co and Mn, so it corresponds to a nickel-based alloy and satisfies the composition of the aforementioned nickel-based alloy. In contrast, spectrum 2 contains 39.5% Al and less than 1% of Ni, Co, and Mn, so it is an alumina-based compound, and XRD (x-ray diffraction) analysis of this material confirmed that it has a LiAlO2 phase rather than an Al2O3 phase. That is, spectrum 2 is not a simple alumina-based compound but a lithium-alumina-based compound, and it can be seen that it satisfies the composition of the aforementioned lithium-based compound.

[0133] Based on the above analysis, it can be confirmed that the bright region of spectrum 1 is a nickel-based alloy and the dark region of spectrum 2 is a lithium-based compound. Through this, it can be seen that the example contains at least some fine nickel-based alloy particles on the surface of the lithium-based compound and is partially melted.

[0134] CategoryCOAlMnCoNispectrum 16.62.3-15.314.461.5spectrum 24.255.439.50.20.1-1.0

[0135] Figure 3 is a digital image of Comparative Example 1.

[0136] Looking at FIG. 3, it can be visually confirmed that the valuable metal recovery composition according to Comparative Example 1 contains a plurality of coarse reactants. Since such coarse reactants typically have large particle sizes and are hard, a problem arises in that an additional milling process is required.

[0137] Figure 4 is a digital image of Comparative Example 2, and Figure 5 is a SEM-EDS (scanning electron microscopy-energy dispersive spectroscopy) image of Comparative Example 2.

[0138] Looking at Fig. 4, it can be seen that the valuable metal recovery composition according to Comparative Example 2 appears to be in a form similar to dust to the naked eye. This is because the flake structure collapses due to excessive heat treatment, forming very small fine particles of reactants. The same applies to Comparative Example 3, which has a rapid heating rate.

[0139] Looking at Fig. 5, it can be seen that the organometallic recovery composition exists as individual fine particles of 100 μm or less, rather than in the form of flat and organically connected flakes as in the example. This supports the reason for having a dust form in Fig. 4 mentioned above.

[0140] Spectra 1 and 5 contain approximately 90 wt% C, excluding Fe and O, indicating that they are graphite. Spectra 2 contains approximately 50 wt% Al and a trace amount of Ni of 0.3 wt% or less, suggesting that it is a lithium-alumina-based compound, i.e., a lithium-based compound. Additionally, spectra 3 and 4 contain approximately 20 wt% Ni and approximately 4 to 8 wt% Co and Mn, indicating that they are nickel-based alloys.

[0141] Based on the above analysis, it can be confirmed that the dark regions of spectrums 1, 2, and 5 correspond to lithium-based compounds or graphite, while the bright regions of spectrums 3 and 4 correspond to nickel-based alloys. In other words, the valuable metal recovery composition according to Comparative Example 2 has fine particles of similar size for each material. In the case of such fine particles similar to graphite, it is difficult to separate the graphite. Furthermore, if the magnetic nickel-based alloy is a fine particle of 100 μm or less, a problem arises in that the effectiveness of magnetic separation is also poor.

[0142] CategoryCOAlPMnFeCoNiCuspectrum 193.95.9---0.2---spectrum 233.05.650.2--0.4-0.3-spectrum 340.54.21.91.37.81.28.228.76.1spectrum 459.5-6.10.53.51.34.517.67.1spectrum 587.3----12.7---

[0143] Figure 6 is a scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) image of Comparative Example 3. Looking at Figure 6, it can be seen that the organometallic recovery composition according to Comparative Example 3 has a particle size and morphology similar to the aforementioned Comparative Example 2. Through this, it is not difficult to infer that the same problems as Comparative Example 2 will occur.

[0144] Spectra 1 to 4 contain 25 to 40 wt% Ni and approximately 10 wt% Co and Mn, indicating that they are nickel-based alloys. Additionally, spectrum 5 contains about 20 wt% Al and a trace amount of 0.4 wt% Ni, indicating that it is a lithium-alumina-based compound, i.e., a lithium-based compound. Spectra 6 to 8 contain 80 to 90 wt% C, indicating that they are graphite.

[0145] Based on the above analysis, it can be confirmed that the bright regions of spectrum 1 to 4 are nickel-based alloys, and the dark regions of spectrum 5 to 8 correspond to lithium-based compounds or graphite.

[0146] As such, the valuable metal recovery composition according to Comparative Example 3 contains nickel-based alloys, lithium-based compounds, and graphite with similar particle sizes. In particular, looking at spectra 4 and 7, a form in which nickel-based alloys and graphite are clustered together is also observed. When nickel-based alloys and graphite, which possess magnetic properties, are clustered together in this way, a problem arises in that the magnetic separation efficiency is low even when the particle size is close to 100 μm.

[0147] CategoryCOFAlMnFeCoNiCuspectrum 134.218.916.800.399.821.1611.6626.77 spectrum 242.33--0.7011.470.628.1729.263.09spectrum 325.78--3.3810.541.528.8139.289.49spectrum 427.393.30-0.2411.620.6110.2840.635.56spectrum 523.8054.22-21.53-0.22-0.22-spectrum 689.799.31--0.210.28 0.42 spectrum 793.726.28-------spectrum 877.0410.123.403.980.780.490.642.210.72

[0148] Evaluation Example 2

[0149] Table 4 below shows the particle size of the valuable metal recovery composition produced when the conditions in the high-temperature reduction step are controlled. The particle size of the valuable metal composition in Table 4 below was measured by the following method.

[0150] Particle size measurement method: The above valuable metal recovery composition was dry particle size screening using sieves of 1000~500 μm, 500~250 μm, 250~150 μm, 150~100 μm, and 100 μm or less.

[0151] Referring to Table 4 above, it can be seen that the optimal size of the resulting reactant is 100 to 1000 μm. Specifically, in the case of the example, it can be confirmed that the particle size of the composition described above is satisfied. In contrast, in Comparative Example 1, it can be seen that the particle size of the reactant is excessively large because the temperature itself is low. In Comparative Examples 2 and 3, it can be seen that fine particles are produced because the temperature is excessively high or the rate of temperature increase is excessively fast.

[0152] The aggregate composition has the problem of low leaching efficiency during leaching, while the fine composition has the disadvantage that magnetic separation is not easy and separation from graphite is difficult. In other words, it can be seen that the particle size of the example corresponds to the optimal particle size range.

[0153] Classification High-temperature reduction step conditions Metal recovery composition Temperature (°C) Heating rate (°C / min) Formula Particle size (μm) Example 1 1,025 3 Satisfied 100~1000, Satisfied Comparative Example 1 6,503 Unsatisfied 2000~5000, Unsatisfied Comparative Example 2 1,300 3 Unsatisfied Fine particles less than 100, Unsatisfied Comparative Example 3 1,025 30 Satisfied Fine particles less than 100, Unsatisfied

[0154] Evaluation Example 3

[0155] Table 5 below shows the compositional analysis of the non-magnetic materials included in the examples and comparative examples. This is because the valuable metal recovery compositions prepared through the examples and comparative examples contain a mixture of magnetic and non-magnetic materials, and the magnetic material in this case does not correspond to the target material of the present invention. The specific analysis method is as follows.

[0156] Analysis Method: A non-magnetic material was obtained by performing magnetic separation using a magnetic separation device with a magnetic strength of 2000 gauss on the powder obtained by dry particle size separation according to Evaluation Example 1 described above. At this time, because Comparative Example 1 had a very large particle size, the dry particle size separation and magnetic separation were performed after undergoing a separate crushing process. Subsequently, the solid samples were completely dissolved through pretreatment and analyzed using an ICP device, and the results are shown in Table 5 below.

[0157] Looking first at the graphite content in Table 5 below, it can be seen that the Example and Comparative Example 2 contain a low level of graphite, with a graphite content of 15 wt% or less. In contrast, Comparative Examples 2 and 3 contain a very large amount of graphite, with a graphite content approximately 38 wt%p higher than that of the Example. When such a large amount of graphite is included, a problem arises in which the efficiency is significantly reduced during leaching in the subsequent process.

[0158] Looking at the valuable metals below, the example contains Li at a content of 4 wt% or more and Al at a content of 21.5 wt% or more, within an appropriate range. In addition, since the content of Ni, Co, and Mn is 2 wt% or less, it can be assumed that the leaching of Li in the subsequent process will be favorable.

[0159] In the case of Comparative Example 1, the content of Ni, Co, and Mn is lower than that of the Example, but Li is included in a small amount of about 1 wt%, while Al is included in a very large amount of about 87 wt%. When the content of Li is low and the content of Al is excessively high, numerous compounds such as Al2O3, in addition to LiAlO2, are formed within the composition, which causes problems by hindering screening and leaching as impurities in subsequent processes. Furthermore, it is presumed that the leaching efficiency for Li will also decrease due to the low content of Li.

[0160] As previously mentioned, Comparative Example 2 is unsuitable because it contains an excessive amount of graphite, which significantly reduces the efficiency of leaching. Additionally, Comparative Example 3 contains Ni at a very high rate of about 20 wt%, which is because magnetic separation is not easy due to the fine composition. Furthermore, it can be seen that the components of Co and Mn are also high at about 5 wt%. In this case, if the leaching of Li is carried out immediately, problems arise such as a significant decrease in efficiency or the need to add separate separation and leaching processes for Ni, Co, and Mn.

[0161] Accordingly, according to one embodiment of the present invention, valuable metals including Li can be obtained in high quality through a simple and economical process.

[0162] Classification Non-magnetic material component content (wt%) LiAlMnCoNi Graphite Al / LiMn / LiCo / LiNi / Li Example 4.5 21.5 1.7 0.5 21 54.7 80.3 80.1 10.4 4 Comparative Example 1 1.1 487.3 20.0 70.0 10.2 33.3 76.6 00.0 60.0 10.2 0 Comparative Example 2 0.7 50.5 60.8 0.6 62.9 290.1 ​​0.7 51.0 70.8 83.8 9 Comparative Example 3 1.9 63.0 65.5 24.9 719.5 653.3 1.5 62.8 22.5 49.9 8

[0163]

[0164] The present invention is not limited to the above embodiments and can be manufactured in various different forms, and those skilled in the art will understand that the invention can be implemented in other specific forms without changing the technical concept or essential features of the invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. Contains lithium-based compounds, and The above lithium-based compound includes Al, and The content of the above Al is 10 to 60 wt% with respect to 100 wt% of the above lithium-based compound, and Having a flake shape, Valuable metal recovery composition.

2. In Paragraph 1, The above composition satisfies the following Formula 1, Valuable metal recovery composition. [Equation 1] 2 ≤ [Al] / [Li] ≤ 20 (In Formula 1 above, [Li] and [Al] each represent the wt% of Li and Al based on 100 wt% of the composition.) 3. In Paragraph 1, The above composition satisfies Formula 2 below, Valuable metal recovery composition. [Equation 2] 0 < [Mn] / [Li] ≤ 4 (In Formula 2 above, [Li] and [Mn] each represent the wt% of Li and Mn based on 100 wt% of the composition.) 4. In Paragraph 1, The above composition satisfies Formula 3 below, Valuable metal recovery composition. [Equation 3] 0 < [Co] / [Li] ≤ 2 (In Formula 3 above, [Li] and [Co] represent the wt% of Li and Co, respectively, based on 100 wt% of the composition.) 5. In Paragraph 1, The above composition satisfies Formula 4 below, Valuable metal recovery composition. [Equation 4] 0 < [Ni] / [Li] ≤ 5 (In Formula 4 above, [Li] and [Ni] respectively represent the wt% of Li and Ni based on 100 wt% of the composition.) 6. In Paragraph 1, The above lithium-based compound comprises at least one of LiAlO2, Li5AlO4, and LiAl5O8, Valuable metal recovery composition.

7. In Paragraph 1, The above composition includes a nickel-based alloy, and The above nickel-based alloy is present on the surface of the above lithium-based alloy, Valuable metal recovery composition.

8. In Paragraph 7, The above nickel-based alloy exists in a partially molten state in at least some region of the above lithium-based compound, Valuable metal recovery composition.

9. In Paragraph 7, The above nickel-based alloy is present at 15% based on 100% of the surface of the above lithium-based compound, Valuable metal recovery composition.

10. In Paragraph 7, The particle size of the above nickel-based alloy is 250 μm or less, Valuable metal recovery composition.

11. In Paragraph 1, The flake shape is such that at least one of the angles where the two outer lines of the composition meet is 90° or less. Valuable metal recovery composition.

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