Battery debris and battery processing method

Abstract

The present invention relates to a battery breaker and a battery processing method, and the battery breaker of the present invention is a battery breaker for recovering valuable metals from a waste battery, which comprises: a positive electrode; a negative electrode disposed on the positive electrode; and a separator disposed between the positive electrode and the negative electrode, wherein the negative electrode comprises fluorine (F) at a content of 5.0 to 15.0% by weight based on a total of 100% by weight of the negative electrode.

Description

Technical Field

[0001] This invention relates to waste batteries, and more particularly to a method for recycling battery fragments and a battery processing method. Background Technology

[0002] Due to environmental concerns, the demand and supply of electric vehicles have increased dramatically, and battery technology is a key element of electric vehicles. The disposal of waste batteries generated by electric vehicles has become a social issue. How to handle these waste batteries is a matter of public concern. These waste batteries use lithium-ion batteries, which contain organic solvents, explosive substances, and heavy metals such as Ni, Co, Mn, Fe, and P, along with carbon and other electrolytes. However, Ni, Co, Mn, Fe, P, and Li are valuable metals with significant scarcity value, making the recycling and reuse of discarded lithium secondary batteries an important research area.

[0003] The waste battery recycling process typically involves disassembling, discharging, crushing, and heat-treating the batteries to recover valuable metals. However, due to the fire and explosion risks associated with battery crushing, various methods have been proposed to mitigate these risks.

[0004] One of the various methods is to deactivate the electrical energy through battery discharge. This battery discharge method involves saline discharge, during which elements such as Na, K, Mg, Ca, and Cl are introduced and included as impurities in the recovered raw materials, potentially reducing the recovery rate of valuable metals. Furthermore, the substances recovered through the aforementioned heat treatment process can yield valuable metal compounds, various lithium compounds such as lithium carbonate, lithium aluminate, and lithium fluoride, as well as a black powder mixed with carbon, the negative electrode material.

[0005] If the battery is discharged at this time, lithium ions in the negative electrode will migrate to the positive electrode. The lithium ions that migrate to the positive electrode exist in the form of lithium oxide. If the discharge is not performed, a large number of lithium ions will remain in the negative electrode, and the lithium may exist in the form of lithium carbonate or lithium fluoride.

[0006] In the lithium compounds, lithium carbonate and lithium fluoride are readily leached from water due to their water solubility, while the lithium oxide in the positive electrode is readily leached from sulfuric acid. Therefore, if the lithium in the battery has a structure that allows for easy leaching in water, lithium can be recovered through water leaching.

[0007] As mentioned above, battery processing methods that can ensure safety while simultaneously improving the recovery rate of valuable metals are receiving increasing attention during battery processing. Summary of the Invention

[0008] Technical problems to be solved One technical problem this invention aims to solve is to provide a battery fragment that ensures stability when added to subsequent processes and has a high content of valuable metals.

[0009] Another technical problem that this invention aims to solve is to provide a battery processing method that ensures stability while achieving a high recovery rate of valuable metals.

[0010] Technical solution According to an embodiment of the present invention, battery fragments are used for recovering valuable metals from waste batteries. The battery fragments comprise: a positive electrode; a negative electrode disposed on the positive electrode; and a separator disposed between the positive electrode and the negative electrode. The negative electrode may contain 5.0 to 15.0% by weight of fluorine (F) based on 100% by weight of the total negative electrode.

[0011] In one embodiment, the battery fragments can satisfy Equation 1 below.

[0012] <Formula 1> 0.25≤[Li] / [F]≤1.00 In Equation 1 above, [Li] and [F] represent the weights of F and Cu in the negative electrode of the battery fragments, respectively.

[0013] In one embodiment, the negative electrode, as an XRD peak, may have a peak value including at least one of 37.5 to 39.5°, 43 to 47°, 63.5 to 67.5°, 76.8 to 80.8°, and 81 to 85°. In one embodiment, the battery fragments may satisfy Equation 2 below.

[0014] <Formula 2> 0.6 ≤ [First Peak Intensity] / [Second Peak Intensity] ≤ 1.0 In Equation 2 above, [first peak intensity] and [second peak intensity] respectively represent the peak intensity in the range of 37.5 to 39.5° and 43.0 to 47.0° of the negative electrode.

[0015] In one embodiment, the negative electrode comprises a lithium compound, which may include lithium fluoride. In one embodiment, the battery fragments may satisfy Formula 3.

[0016] <Formula 3> [F] / [Cu]≤30 In Equation 3 above, [F] and [Cu] represent the weights of F and Cu in the negative electrode of the battery fragments, respectively.

[0017] In one embodiment, the battery fragments may have a layered structure comprising the positive electrode or a separator having the negative electrode stacked on at least one side. In one embodiment, the fluorine content in the negative electrode may be from 1.0 to 12.0% by weight, based on 100% by weight. In one embodiment, the lithium content in the negative electrode may be from 1.0 to 5.0% by weight, based on 100% by weight.

[0018] A battery processing method according to another embodiment of the present invention may include: a step of preparing a battery having a voltage of 2.0 to 3.7V; a step of freezing the battery; and a step of crushing the battery. In one embodiment, the step of preparing the battery includes a step of discharging the battery, which may include a step of applying a current of less than 5A. In another embodiment, the step of discharging the battery may be performed for 4 to 8 hours.

[0019] In one embodiment, freezing the battery may involve cooling the battery to -150°C to -20°C. In another embodiment, freezing the battery may be performed for 15 to 36 hours.

[0020] In one embodiment, the battery fragments processed via the battery crushing step comprise a negative electrode, wherein the fluorine (F) content of the negative electrode is 5.0 to 15.0% by weight, based on 100% by weight of the total negative electrode. In one embodiment, the battery fragments may satisfy Formula 1.

[0021] <Formula 1> 0.25≤[Li] / [F]≤1.00 In Equation 1 above, [Li] and [F] represent the weights of F and Cu in the negative electrode of the battery fragments, respectively.

[0022] Beneficial effects According to one embodiment of the present invention, the battery fragments contain a high content of fluorine, thus facilitating the application of water-immersed lithium compounds with a high content, thereby providing battery fragments that are safe and improve the recovery rate of valuable metals.

[0023] According to another embodiment of the present invention, a battery processing method is provided to perform a low-temperature processing and crushing process based on the state of charge (SOC) while the battery is not discharged and lithium remains in the negative electrode, thereby providing a method for obtaining battery fragments with a high content of lithium compounds that are easily immersed in water. Attached Figure Description

[0024] Figure 1a and Figure 1b This is a photograph of broken battery material according to an embodiment of the present invention.

[0025] Figure 2a and Figure 2b The XRD analysis results of the negative electrode material in the fragments of the embodiment and comparative example according to one embodiment of the present invention are shown.

[0026] Figures 3a to 3c The SEM-EDS analysis results of the negative electrode material according to an embodiment of the present invention are shown. Detailed Implementation

[0027] The terms "first," "second," "third," etc., are used to describe parts, components, regions, layers, and / or segments, but these parts, components, regions, layers, and / or segments should not be limited by these terms. These terms are only used to distinguish one part, component, region, layer, or segment from another. Therefore, without departing from the scope of the invention, the first part, component, region, layer, or segment described below can also be described as a second part, component, region, layer, or segment.

[0028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. Unless the context clearly indicates otherwise, the singular forms used herein are intended to include the plural forms as well. The word "comprising" as used in the specification can specifically refer to a feature, domain, integer, step, action, element, and / or component, but does not exclude the presence or addition of other features, domains, integers, steps, actions, elements, and / or components.

[0029] If one part is described as being on top of another part, then other parts may exist directly on top of or in between the other part. If one part is described as being directly on top of another part, then no other parts exist in between.

[0030] Although not otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in dictionaries should be interpreted as having the same meaning as disclosed in relevant technical literature and herein, and should not be interpreted in an idealized or overly formal sense.

[0031] Embodiments of the present invention will be described in detail below. However, the following embodiments are given by way of example only, and the present invention is not limited to the following embodiments; the present invention is defined only by the scope of the claims.

[0032] According to one embodiment of the present invention, a battery fragment for recovering valuable metals from waste batteries may comprise: a positive electrode; a negative electrode disposed on the positive electrode; and a separator disposed between the positive electrode and the negative electrode. Specifically, the battery fragment may be a layered structure. More specifically, the battery fragment is a layered structure composed of multiple layers, the number of layers of which may correspond to the number of separators.

[0033] The layered structure may include, for example, a positive electrode-separator-negative electrode or a negative electrode-separator-positive electrode. For instance, a positive electrode-separator-negative electrode-separator-positive electrode-separator-negative electrode structure may be a three-layered structure. Specifically, for battery fragments, as at least one or more layered bodies are stacked, the thickness in the thickness direction may have a predetermined thickness.

[0034] In one embodiment, the broken battery material may satisfy the following condition 1.

[0035] <Condition 1> The layered structure can be a stacked structure with more than one layer and less than seven layers.

[0036] The battery fragments can be a layered structure with one to seven layers. Specifically, the layered structure can be a layered structure with one to five layers. As the layered structure is stacked within this range, the temperature rise of the fragments is minimized, and the heating time is appropriately reduced. If the layer thickness exceeds the upper limit of this range, the temperature rise increases excessively, the heating time also increases, and there is a risk of fire during combustion.

[0037] In one embodiment, the broken battery material may satisfy the following condition 2.

[0038] <Condition 2> The size of the battery fragments can be less than 100mm based on the longest axis of the longest axis in the horizontal, vertical and vertical directions.

[0039] In one embodiment, the battery fragments, with their long axis as a reference, can have a size of less than 100 mm. Specifically, the size of the battery fragments can be less than 50 mm. If the size of the battery fragments is too large, the temperature of the battery fragments themselves can rise above 100°C, posing a higher risk of fire.

[0040] In one embodiment, the battery fragments may satisfy Equation 1 below.

[0041] <Formula 1> 0.25≤[Li] / [F]≤1.00 In Equation 1 above, [Li] and [F] represent the weights of Li and F in the negative electrode of the battery fragments, respectively.

[0042] Formula 1 above describes the ratio of Li and F content in the negative electrode of the battery fragments, and can be a qualitative indicator of the amount of lithium fluoride formed in the lithium compound. Formula 1 can satisfy values ​​from 0.25 to 1.00, specifically 0.57 to 1.00, more specifically 0.60 to 0.80, and more specifically 0.60 to 0.65. Because Formula 1 satisfies the aforementioned range, lithium and fluorine in the negative electrode easily form compounds, and lithium fluoride (LiF) remains in the negative electrode. In subsequent processes, lithium fluoride can be easily separated from the negative electrode by water immersion, which can improve the lithium recovery rate.

[0043] If Equation 1 exceeds the upper limit of the aforementioned range, it indicates that the proportion of lithium fluoride in the lithium compound is relatively small. If Equation 1 exceeds the lower limit of the aforementioned range, due to insufficient lithium, there is a problem that fluorine cannot form lithium fluoride and instead forms other substances. In the case of HF gas, this can lead to equipment corrosion.

[0044] In one embodiment, the negative electrode may contain a lithium compound, which may contain lithium fluoride. Regarding the lithium fluoride, during forced discharge of the waste battery to stabilize it, lithium ions migrate towards the positive electrode, forming the lithium fluoride within the positive electrode. In the battery fragments of the present invention, during the battery processing method, after freezing the battery while maintaining its internal voltage within a predetermined range, lithium does not migrate towards the positive electrode but remains within the negative electrode; therefore, the lithium fluoride can be contained in the negative electrode rather than the positive electrode.

[0045] Since the lithium fluoride is contained in the negative electrode rather than the positive electrode of the battery fragments, subsequent processes can easily separate it through water immersion. Because the lithium fluoride is contained in the negative electrode, no complex processes are required, and it has the advantage of being easily separated by water immersion.

[0046] In one embodiment, the negative electrode, as an XRD peak, may have a peak value including at least one of 37.5 to 39.5°, 43 to 47°, 63.5 to 67.5°, 76.8 to 80.8°, and 81.0 to 85.0°. Since the negative electrode, as a lithium compound, contains lithium fluoride, it may have the aforementioned peak values.

[0047] In one embodiment, the battery fragments may satisfy Equation 2 below.

[0048] <Formula 2> 0.6 ≤ [First Peak Intensity] / [Second Peak Intensity] ≤ 1.0 In Equation 2 above, [first peak intensity] and [second peak intensity] respectively represent the peak intensity in the range of 37.5 to 39.5° and 43 to 47° of the negative electrode.

[0049] Equation 2 above relates to the peak intensity ratio of lithium fluoride in the negative electrode of the battery fragments. It can be an indicator that can confirm the presence or absence of lithium fluoride residue in the negative electrode based on whether the battery has been discharged. Equation 2 can satisfy a value of 0.6 to 1.0. Specifically, Equation 2 can satisfy a value of 0.7 to 0.9.

[0050] Since Equation 2 satisfies the aforementioned range, the negative electrode in the battery fragments contains appropriate amounts of lithium fluoride. Therefore, in subsequent processes, lithium fluoride can be easily separated from the negative electrode by water immersion, which can improve the lithium recovery rate.

[0051] In one embodiment, the battery fragments can satisfy Equation 3 below.

[0052] <Formula 3> [F] / [Cu]≤30 In Equation 3 above, [F] and [Cu] represent the weights of F and Cu in the negative electrode of the battery fragments, respectively.

[0053] Formula 3 above represents the fluorine content ratio relative to copper in the negative electrode of the battery fragments. It can be used as an indicator to confirm the presence or absence of lithium fluoride residue in the negative electrode, based on whether the battery has been discharged. Formula 3 can satisfy a value below 30%, specifically below 20%, more specifically below 10%, and more specifically between 2 and 8%. Since Formula 3 meets the aforementioned ranges, the negative electrode in the battery fragments appropriately contains lithium fluoride. Therefore, in subsequent processes, lithium fluoride can be easily separated from the negative electrode through water immersion, thereby improving the lithium recovery rate.

[0054] In one embodiment, the fluorine content in the negative electrode can be from 1.0 to 12.0% by weight, based on 100% by weight. Specifically, the fluorine content can be from 2.0 to 8.5% by weight, more specifically, from 2.3 to 6.0% by weight, and more specifically, from 3.0 to 5.5% by weight. Since the fluorine content in the negative electrode meets the aforementioned range, lithium compounds such as lithium fluoride are appropriately formed within the negative electrode, making it easier to separate the lithium compounds in subsequent processes and improving lithium recovery.

[0055] In one embodiment, the lithium content in the negative electrode can be from 1.0 to 5.0% by weight, specifically from 1.3 to 4.3% by weight, and more specifically from 2.0 to 3.5% by weight. Since the fluorine content in the negative electrode meets the aforementioned range, lithium compounds such as lithium fluoride are appropriately formed within the negative electrode, making it easier to separate these lithium compounds in subsequent processes and improving lithium recovery rates.

[0056] Since the negative electrode contains both lithium and fluorine, lithium compounds such as lithium fluoride can be formed. If the fluorine content is too high, other fluorinated substances such as HF may be generated in addition to lithium fluoride. If the lithium and fluorine content is too low, the yield may decrease.

[0057] A battery processing method according to another embodiment of the present invention may include: a step of preparing a battery; a step of freezing the battery; and a step of crushing the battery. Specifically, the battery processing method of the present invention may be a battery processing method in which a battery having a predetermined voltage is frozen and then crushed, and lithium ions migrate towards the positive electrode during individual discharge, while lithium fluoride is formed at the negative electrode instead of the positive electrode, so that the lithium fluoride can be easily separated in subsequent processes by methods such as water immersion.

[0058] The battery preparation process can involve preparing a battery with a voltage of 3.0 to 4.5V. This battery can be, for example, a lithium-ion secondary battery derived from a car, or a secondary battery derived from electronic devices such as mobile phones, cameras, and laptops; specifically, it can be a lithium-ion secondary battery. This battery, at 100% SOC, can have a voltage of approximately 4.2 to 4.5V.

[0059] The battery preparation step may include controlling a battery with a voltage of 3.0 to 4.5V to a voltage of 1.5 to 3.7V. Specifically, the battery of the present invention can be controlled to have a voltage of 1.5 to 3.7V. Specifically, the voltage may be 2.0 to 3.7V. Because the battery has a voltage within the aforementioned range, it has the advantage of being able to be stably broken through cryogenic treatment.

[0060] If the battery has a voltage higher than the aforementioned range, there is a risk of fire during or after breakage, even with cryogenic treatment. If the battery has a voltage lower than the aforementioned range, the lithium fluoride content in the negative electrode is too low, resulting in a decrease in lithium recovery rate.

[0061] The battery preparation step includes discharging the battery, which may involve applying a current of 5A or less. Specifically, the current can be controlled to be 3A or less, more specifically 2A or less. Controlling the battery voltage within this current range has the advantage of easily controlling the degree of voltage recovery after discharge. If the battery is discharged within a current range higher than this range, the degree of voltage recovery becomes greater, making it difficult to achieve battery stabilization.

[0062] In one embodiment, the battery discharge step can be performed for 4 to 8 hours. Specifically, the battery discharge step can be performed for 5 to 7 hours. Because the battery discharge step is performed within the aforementioned current range, the battery discharges slowly and can be discharged within the aforementioned time period. Because the battery discharge is performed within the aforementioned range, the degree of rebound after battery discharge is reduced, which has the advantage of easily achieving battery stabilization.

[0063] In one embodiment, the freezing step of the battery is performed at a temperature sufficient to freeze the electrolyte contained within the battery. Specifically, for example, the freezing step can be performed in a temperature range of -150 to -20°C. More specifically, the temperature range is -100 to -20°C, and even more specifically, it can be performed in a temperature range of -90 to -40°C.

[0064] If the battery is frozen within the stated temperature range, the trace residual voltage inside the battery, such as approximately 2V to 3V, drops to near 0V. Therefore, even if a short circuit occurs where the positive and negative electrodes are in direct contact, no battery reaction will occur, and the battery temperature will not increase, thus preventing the generation and combustion of electrolyte gases. Furthermore, with the electrolyte in a frozen or suppressed vaporization state, the lithium-ion mobility is very low, and the electrical conductivity based on lithium-ion migration is significantly reduced. Electrolyte vaporization does not occur, therefore no flammable gases such as ethylene, propylene, and hydrogen are produced.

[0065] If the freezing process exceeds the specified temperature range, the residual voltage inside the battery will not drop to 0V, potentially leading to a short circuit and battery reaction. The electrolyte will not be completely frozen, making this process unsuitable. As described above, including a freezing step before breaking up batteries such as lithium-ion batteries offers the advantage of preventing the fire risk that may occur during the battery breaking process.

[0066] In one embodiment, the freezing step of the battery can be performed for 10 to 36 hours. Alternatively, the freezing step can be performed for 12 to 30 hours, specifically 12 to 24 hours. Because the freezing step is performed within the aforementioned time range, battery stabilization is easily achieved, and if the battery is broken, it can prevent the battery from causing a fire.

[0067] If the time taken for the battery freezing step is significantly longer than the stated time, it becomes uneconomical. If the time taken for the battery freezing step is significantly shorter than the stated time, battery stabilization may be difficult to achieve.

[0068] The step of crushing the frozen battery can refer to a process of applying impact or pressure to the battery to cause a portion of the battery to detach from the battery. In one embodiment, the battery crushing step can refer to all processes of pulverizing the battery, cutting the battery, compressing the battery, and combinations thereof. Specifically, the crushing step can include all processes capable of destroying the battery to obtain small fragments.

[0069] In one embodiment, the battery crushing step may include all processes of compressing a frozen battery or applying external forces such as shear or tensile forces to destroy the battery. For example, the battery crushing step may be carried out using a crusher.

[0070] In one embodiment, the battery breaking step may be performed at least once. Specifically, the breaking step may be performed continuously or discontinuously at least once.

[0071] In one embodiment, the step of crushing the battery can be carried out under conditions of supplying inert gas, carbon dioxide, nitrogen, water, or a combination thereof, or under vacuum conditions below 100 Torr. For example, when the process of freezing the battery is carried out by cooling in a temperature range of -90 to -20°C, if carried out under the aforementioned conditions, the reaction between the electrolyte and oxygen can be prevented by suppressing the oxygen supply, thus preventing an explosion, and the vaporization of the electrolyte is suppressed, so that flammable gases such as ethylene, propylene, or hydrogen are not produced.

[0072] Preferred embodiments and comparative examples of the present invention are described below. However, the following embodiments are merely preferred embodiments of the present invention, and the present invention is not limited to the following embodiments.

[0073] <Experimental Example> <Example 1> Battery preparation steps When the SOC was 100%, an NCM622 lithium-ion battery with approximately 4.2V was prepared. Next, the battery voltage was measured. At this point, the initial battery was discharged to 1.0V within 1 hour by applying a 5A current, and the degree of recovery within 24 hours was confirmed, resulting in a battery with a final voltage of 3.7V and an SOC of 50%.

[0074] At this point, since the current was controlled within the specified range, it was confirmed that the voltage would rise to 2.5V after discharging to 0V. However, when discharging at 10A (6A or higher), the voltage would rise to 3V after discharging to 0V within 3 hours. Therefore, in Example 1, a step of slowly discharging the battery with a low current was performed.

[0075] Ultra-low temperature treatment steps The battery was subjected to cryogenic treatment at -60°C for 24 hours.

[0076] Battery breakage steps The batteries that have undergone the aforementioned cryogenic treatment are crushed in a particle size range of 5 to 80 mm using a dual-shaft, two-stage crusher.

[0077] Figure 1a and Figure 1bThis is a photograph of broken battery material according to an embodiment of the present invention.

[0078] Reference Figure 1a and Figure 1b It can be confirmed that, according to an embodiment of the present invention, the battery fragments have a layered structure in their positive electrode, negative electrode and separator, and the size of the fragments is less than 100 mm.

[0079] <Example 2> In the step of measuring the battery voltage, the battery is prepared to be discharged to a voltage of 2.0V within 1 hour by applying a current of 3A. Otherwise, it is performed in the same manner as in Example 1.

[0080] <Comparative Example 1> In the battery preparation step, the 3.5V battery is discharged by applying a 5A current and discharged to 0V within 2 hours. After finally controlling the voltage to be below 0.5V, it does not undergo a separate cryogenic treatment step. Otherwise, it is carried out in the same way as in Example 1.

[0081] Table 1 below shows the compositional analysis results of the negative electrode material in the fragments based on the battery voltage. The battery voltage and the compositional analysis of the negative electrode material were performed using the following methods.

[0082] Battery voltage (V): The battery voltages in Table 1 below represent the initial battery voltage and the voltage of the battery after discharge. The battery voltage is measured by contacting the positive and negative terminals of the battery with a voltage measuring device.

[0083] Compositional analysis: The negative electrode material was extracted from the crushed material by particle size sieving. The lithium (Li) component in the negative electrode material was analyzed using an ICP (inductively coupled plasma) device, the fluorine (F) component was determined using combustion ion chromatography from Dionex, and the carbon (C) component was analyzed using a C / S device from LECO.

[0084] Table 1

[0085] As confirmed by Table 1 above, Comparative Example 1, which underwent discharge, had a lower lithium content, with most of the lithium component located in the positive electrode sample. The residual fluorine, formed from compounds with the lithium, also had a lower value. In contrast, the fragments from Example 1, which involved a higher-voltage battery undergoing cryogenic treatment without discharge, showed higher lithium and fluorine content in the negative electrode material.

[0086] It has been confirmed that the lithium and fluorine content in the negative electrode material of the battery with a voltage lower than that of Comparative Example 1 is higher than that of Comparative Example 1, but lower than that of Comparative Example 1. This indicates that the battery with a high voltage has relatively more lithium ions located on the negative electrode side, and the lithium located on the negative electrode easily reacts with the surrounding fluorine to form lithium fluoride, which remains there. This is because the negative electrode material in the fragment of Example 1, which has a high battery voltage, has a higher lithium and fluorine content than the negative electrode material in the fragment of Example 2, which has a low battery voltage.

[0087] Furthermore, for batteries with voltages higher than those in Example 1, such as 4.0V, even with low-temperature treatment, there is a risk of fire during the breakage process, thus confirming that battery treatment is not very suitable.

[0088] Figure 2a and Figure 2b The XRD analysis results of the negative electrode material in the fragments of the embodiment and comparative example according to one embodiment of the present invention are shown.

[0089] Figure 2a and Figure 2b The graphs show the XRD analysis results of the negative electrode materials extracted from the fragments of Example 1 and Comparative Example 1, respectively. The XRD analysis was performed using an X-ray diffraction analyzer from RIGAKU Corporation, measuring the diffraction intensity at different angles.

[0090] Refer to Figure 2a When discharging, lithium excessively migrates to the positive electrode material in the battery fragments during the discharge process. Not only are only substances such as C or Cu detected in the negative electrode material, but no peak values ​​of lithium and fluorine are also detected.

[0091] Refer to Figure 2b When performing cryogenic treatment on a 3.5V battery without discharge, it was confirmed that the negative electrode material in the fragments contained not only C peak values ​​but also LiF peak values. This is because, without discharge, the residual lithium and fluorine in the negative electrode material remained directly in the negative electrode material during the cryogenic process.

[0092] Table 2 below shows the peak values ​​of the XRD peak values ​​based on the negative electrode material according to an embodiment of the present invention.

[0093] Table 2

[0094] As confirmed in Table 2 above, no LiF peak was detected in Comparative Example 1. It has been confirmed that LiF peaks appeared in the negative electrode material in Examples 1 and 2, and Formula 2 falls within the scope of this invention. This indicates that in high-voltage batteries, relatively more lithium ions are located on the negative electrode side. The lithium at the negative electrode readily reacts with the surrounding fluorine to form lithium fluoride, which remains. Therefore, LiF peaks were detected in Examples 1 and 2, which have high battery voltages. It has been confirmed that the ratio of the second peak to the first peak satisfies the scope of this invention.

[0095] Figures 3a to 3c The SEM-EDS analysis results of the negative electrode material according to an embodiment of the present invention are shown.

[0096] Figures 3a to 3c These are the SEM-EDS analysis results of Comparative Example 1, Example 1, and Example 2 of the present invention, respectively.

[0097] Table 3 below shows the SEM-EDS analysis results of the negative electrode material according to an embodiment of the present invention.

[0098] The SEM-EDM of the negative electrode material was measured using a SEM-EDS device from JEOL Corporation.

[0099] Table 3

[0100] from Figure 3a , Figure 3b As confirmed in Table 3, in Comparative Example 1, lithium migrates towards the positive electrode during forced discharge, resulting in a lower fluorine content. In contrast, it has been confirmed that in Examples 1 and 2, lithium remains in the negative electrode, where it reacts with fluorine to form lithium fluoride, resulting in a higher fluorine content. Therefore, the examples show an excess of lithium fluoride formation, which allows for improved recovery of valuable metals through water leaching in subsequent processes.

[0101] The preferred embodiments have been described in detail above, but the scope of the present invention is not limited to the above embodiments. Various modifications and improvements made by those skilled in the art using the basic concepts defined in the claims also fall within the scope of the present invention.

Claims

1. A battery shredded material for recovering valuable metals from waste batteries, said battery shredded material comprising: positive electrode; The negative electrode is disposed on the positive electrode; A diaphragm is disposed between the positive electrode and the negative electrode. The negative electrode contains 5.0 to 15.0% fluorine (F) per 100% by weight of the total negative electrode.

2. The battery fragments according to claim 1, wherein, The battery fragments satisfy the following formula 1. <Formula 1> 0.25≤[Li] / [F]≤1.00 In Equation 1 above, [Li] and [F] represent the weights of F and Cu in the negative electrode of the battery fragments, respectively.

3. The battery fragments according to claim 1, wherein, The negative electrode, as an XRD peak, has a peak value including at least one of 37.5 to 39.5°, 43 to 47°, 63.5 to 67.5°, 76.8 to 80.8°, and 81 to 85°.

4. The battery fragments according to claim 1, wherein, The battery fragments satisfy the following formula 2. <Formula 2> 0.6 ≤ [First Peak Intensity] / [Second Peak Intensity] ≤ 1.0 In Equation 2 above, [first peak intensity] and [second peak intensity] respectively represent the peak intensity in the range of 37.5 to 39.5° and 43.0 to 47.0° of the negative electrode.

5. The battery fragments according to claim 1, wherein, The negative electrode contains a lithium compound. The lithium compound includes lithium fluoride.

6. The battery fragments according to claim 1, wherein, The battery fragments satisfy the following formula 3. <Formula 3> [F] / [Cu]≤30 In Equation 3 above, [F] and [Cu] represent the weights of F and Cu in the negative electrode of the battery fragments, respectively.

7. The battery fragments according to claim 1, wherein, The battery fragments have a layered structure containing the positive electrode or a separator on at least one side having the negative electrode stacked on it.

8. The battery fragments according to claim 1, wherein, The fluorine content in the negative electrode is 1.0 to 12.0% by weight, calculated as 100% by weight.

9. The battery fragments according to claim 1, wherein, The lithium content in the negative electrode is 1.0 to 5.0% by weight, based on 100% by weight of the negative electrode.

10. A battery processing method, comprising: Steps for preparing a battery with a voltage of 3.0 to 4.5V; The step of freezing the battery; and The step of crushing the battery. The battery preparation step includes controlling a battery with a voltage of 3.0 to 4.5V to a voltage of 1.5 to 3.7V.

11. The battery processing method according to claim 10, wherein, The battery preparation step includes the step of discharging the battery. The step of discharging the battery includes applying a current of less than 5A.

12. The battery processing method according to claim 11, wherein, The battery is discharged for 4 to 8 hours.

13. The battery processing method according to claim 10, wherein, The step of freezing the battery is to cool the battery to -150°C to -20°C.

14. The battery processing method according to claim 10, wherein, The freezing process of the battery is carried out for 15 to 36 hours.

15. The battery processing method according to claim 10, wherein, The battery fragments processed through the aforementioned battery crushing step contain the negative electrode. For the negative electrode, the fluorine (F) content is 5.0 to 15.0% by weight, based on 100% of the total negative electrode weight.

16. The battery processing method according to claim 15, wherein, The battery fragments satisfy the following formula 1. <Formula 1> 0.25≤[Li] / [F]≤1.00 In Equation 1 above, [Li] and [F] represent the weights of F and Cu in the negative electrode of the battery fragments, respectively.

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