Battery disposal method

Abstract

The present invention relates to a battery processing method, more particularly to a method for processing waste batteries, and includes the steps of preparing a battery, measuring the voltage of the battery, performing low-temperature processing on the battery at a temperature below a minimum temperature determined by the battery's voltage, and crushing the battery, wherein the minimum temperature satisfies the following formula 1. <Expression 1> Minimum temperature = 21.42857 + (-21.1255) × voltage + (-0.69264) × voltage 2 ±0.5 (In equation 1 above, voltage refers to the cell reference voltage of the battery.)

Description

[Technical Field]

[0001] This concerns waste batteries, and more specifically, methods for crushing batteries recovered from waste batteries. [Background technology]

[0002] Electric vehicles, whose demand and supply are rapidly increasing due to environmental concerns, rely on battery technology as a core element. The disposal of waste batteries generated from such electric vehicles has become a social problem. Such batteries for electric vehicles are rechargeable secondary batteries and are characterized by containing lithium. The core components of the battery include a positive electrode material, a negative electrode material, a current collector, an electrolyte, and a separator membrane.

[0003] The positive electrode material uses Ni, Co, and Mn oxides as raw materials, and the negative electrode material uses carbon. The current collector uses Al and Cu foil. The battery is assembled from the smallest unit, the cell, into a pack for automotive use, and in this process, a plastic case and iron bolts, nuts, and frames are used. Of these, Li, Ni, Co, and Mn are valuable metals, and Li in particular has seen a sharp increase in value recently. As a result, there is growing interest in the recovery and reuse of these rare components.

[0004] Even after automotive batteries reach the end of their lifespan, they can be reused in other fields. These other fields may include, for example, energy storage systems (ESS). After reuse in such energy storage systems, the batteries that have reached the end of their lifespan are treated as waste batteries.

[0005] The process of recovering the aforementioned waste batteries generally involves dismantling, discharging, crushing, and heat treatment to produce black mass, which is then used as a raw material for cathode materials through wet refining. However, there is a risk of fire and explosion during the crushing process, and various methods for safe crushing are being researched.

[0006] A typical method for safely dismantling the aforementioned battery is water discharge using water or saltwater. However, this method is labor-intensive because it requires dismantling the battery down to the cell level and additional processing to allow the solution inside the cell to penetrate, and it is also environmentally unfriendly as it generates wastewater. In addition, there is the problem of contamination of components such as Na, Cl, K, and Mg when using saltwater.

[0007] Thus, there is growing interest in safe yet environmentally friendly battery disposal methods as the first step towards reusing waste batteries. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The technical problem that this invention aims to solve is to provide a battery processing method for safely crushing waste batteries. [Means for solving the problem]

[0009] A battery processing method according to one embodiment of the present invention relates to a method for processing a waste battery, and includes the steps of preparing the battery, measuring the voltage of the battery, performing low-temperature processing on the battery at a temperature below a minimum temperature determined by the battery's voltage, and crushing the battery, wherein the minimum temperature satisfies the following formula 1.

[0010] <Expression 1> Minimum temperature = (21.42857 + (-21.1255) × voltage + (-0.69264) × voltage) 2 ) ±0.5

[0011] (In equation 1 above, voltage refers to the battery voltage.)

[0012] In one embodiment, the voltage of the battery measured in the step of measuring the voltage of the battery may be 0 to 4.2V based on the cell. In one embodiment, the step of low-temperature processing can be performed by processing the battery at 10°C or below.

[0013] In one embodiment, the low-temperature processing step involves processing the battery for a minimum freezing time or longer, and the minimum freezing time can satisfy the following formula 2.

[0014] <Expression 2> Minimum freezing time = (1.55461 + (-0.06551 × target temperature) + (7.47E-5 × target temperature) 2 ))×Weight 0.32 ±0.45

[0015] (In equation 2 above, target temperature refers to the target temperature (°C) for low-temperature processing of the battery, and weight refers to the weight of the battery (kg).)

[0016] In one embodiment, when the battery is subjected to a low-temperature treatment for a minimum freezing time or longer by the voltage of the battery, if the battery is a module having multiple cells, the freezing completion time of the battery may be 10 hours or more. In one embodiment, the module may have a weight of 28 to 32 kg.

[0017] In one embodiment, when the battery is a cell, the time required to complete freezing of the battery may be 2 hours or more, in the step of treating the battery to a low temperature for a minimum freezing time or longer based on the battery's voltage. In one embodiment, the cell may have a weight of 0.5 to 1.5 kg.

[0018] In one embodiment, the step of crushing the battery can crush the battery within a particle size range of 5 to 80 mm. In one embodiment, the step of crushing the battery can be carried out using a two-axis two-stage shredder.

[0019] In one embodiment, the step of measuring the voltage of the battery can include the step of reducing the voltage of the battery. In one embodiment, the battery crush product obtained through the step of crushing the battery can satisfy the following Condition 1 or Condition 2.

[0020] <Condition 1> The layered structure can be a laminated structure of 1 or more to 7 or less layers.

[0021] <{ <Condition 2> The size of the battery crush product can be 100 mm or less based on the long axis, which is the longest axis among the horizontal, vertical, and height directions.

Advantages of the Invention

[0022] The battery processing method according to an embodiment of the present invention provides a processing method for safely crushing a battery by controlling the minimum cooling temperature based on the voltage of the cells inside the battery.

Brief Description of the Drawings

[0023] [Figure 1a] It is a photograph of a battery crush product according to an embodiment of the present invention. [Figure 1b] It is a photograph of a battery crush product according to an embodiment of the present invention. [Figure 2a] It shows that ignition occurs from the battery during the crushing stage of the present invention. <000W0104> [Figure 2b] It shows that ignition occurs from the battery during the crushing stage of the present invention. [Figure 3a] It shows the measurement of the temperature of the shredder and the crush product during the crushing stage of the present invention. [Figure 3b] It shows the measurement of the temperature of the shredder and the crush product during the crushing stage of the present invention. [Figure 4] This shows the freezing time required based on the module's temperature. [Modes for carrying out the invention]

[0024] The terms First, Second, and Third are used to describe various parts, components, regions, layers, and / or sections, but are not limited to these. These terms are used solely to distinguish one part, component, region, layer, or section from other parts, components, regions, layers, or sections. 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.

[0025] The technical terms used herein are for the sole purpose of referring to specific embodiments and are not intended to limit the invention. The singular form used herein also includes the plural form unless the phrase expressly indicates otherwise. The meaning of “including” as used in this specification is to embody a particular characteristic, area, integer, stage, operation, element, and / or component, and does not exclude the presence or addition of other characteristics, areas, integers, stages, operations, elements, and / or components.

[0026] When one part is described as being "on top of" or "on" another part, it may be directly on top of or on the other part, or the other part may be present between them. In contrast, when one part is described as being "directly on top of" another part, there is no other part in between them.

[0027] Although not defined differently, all terms used herein, including technical and scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries are interpreted in addition to having meanings that correspond to relevant technical documents and the content currently disclosed, and are not interpreted in their ideal or highly formal sense unless otherwise defined.

[0028] Embodiments of the present invention will be described in detail below. However, these are presented as examples only and do not limit the present invention, which is defined solely by the scope of the claims described later.

[0029] A battery processing method according to one embodiment of the present invention may be a method for processing waste batteries. Specifically, it includes the steps of preparing a battery, measuring the voltage of the battery, performing low-temperature processing on the battery at a temperature below the minimum temperature determined by the battery's voltage, and crushing the battery. Specifically, the battery processing method of the present invention may be a method that can stably process batteries without causing fires during crushing by performing a low-temperature processing step at a minimum freezing temperature or higher determined by the battery's voltage.

[0030] In the battery preparation stage, the battery may be, for example, a lithium secondary battery separated from an automobile, or a secondary battery separated from an electronic device such as a mobile phone, camera, or laptop computer, specifically a lithium secondary battery. Specifically, the battery may be a used battery that has reached the end of its lifespan. The battery may have a voltage of about 4.5V under 100% SOC conditions. The battery of the present invention may have a voltage of 2.0 to 4.5V. Specifically, the voltage may be 2.5 to 4.0V, and more specifically, 3.0 to 4.0V.

[0031] The step of measuring the voltage of the battery may be a step of measuring the voltage of the battery. For example, the step of measuring the voltage of the battery may be a step of measuring the voltage of a module, pack, or cell. Specifically, the step of measuring the voltage of the battery may be a step of measuring the voltage of a cell. Specifically, the step of measuring the voltage may be a step of measuring the voltage of the cell by using a general tester to connect the terminals to the positive and negative terminals of the battery. The step of measuring the voltage of the battery may be a step of determining the state of the battery in order to freeze the battery for the minimum freezing time described later.

[0032] In one embodiment, the voltage of the battery measured during the voltage measurement step may be 0 to 4.2V on a cell basis. Specifically, the waste battery may have about 4.2V under 100% SOC conditions, and a voltage lower than 4.2V may be measured.

[0033] In one embodiment, the step of measuring the battery voltage may include a step of reducing the battery voltage. Specifically, the battery voltage can be controlled to a voltage of 0 to 4.2V relative to the cells within the battery. The step of reducing the battery voltage can be controlled, for example, by controlling the voltage of the cells within the battery through electrical discharge.

[0034] The step of treating the battery at a temperature below the minimum temperature determined by the battery's voltage may also be a step of freezing and stabilizing the electrolyte contained within the battery. By treating the battery at a temperature below the minimum temperature, it is possible to prevent fires from occurring due to hazardous materials such as the electrolyte when the battery is crushed.

[0035] In one embodiment, the minimum temperature can satisfy the following formula 1.

[0036] <Expression 1> Minimum temperature = 21.42857 + (-21.1255) × voltage + (-0.69264) × voltage 2 ±0.5

[0037] (In equation 1 above, voltage refers to the cell reference voltage (V) of the battery.)

[0038] Equation 1 represents the minimum cooling temperature of the battery cells based on the reference voltage during the low-temperature processing stage of the battery. Equation 1 is calculated as 21.42857 + (-21.1255) × voltage + (-0.69264) × voltage 2 -0.5 lower limit and 21.42857 + (-21.1255) × voltage + (-0.69264) × voltage 2It has an upper limit of +0.5, and in the battery low-temperature processing stage, it is possible to perform low-temperature processing at a temperature below the lower limit and upper limit range of the above formula 1.

[0039] By satisfying Equation 1, low-temperature processing of batteries with a specific voltage can be easily performed, minimizing the occurrence of battery fires during the crushing stage. If Equation 1 deviates from the aforementioned range when low-temperature processing of batteries is performed, the stabilization of batteries with a specific voltage may not proceed smoothly, and problems such as fires may occur when crushing the batteries.

[0040] In one embodiment, the low-temperature processing step may be a step in which the battery is processed at a temperature of 10°C or lower. Specifically, when the voltage of the battery is 1.0V or lower, the low-temperature processing step can be performed at a temperature of 0°C or lower. More specifically, when the voltage of the battery is 1.5 to 2.0V, the battery can be low-temperature processed at a temperature of -15°C or lower. More specifically, when the voltage of the battery is approximately 2.5V, the battery can be low-temperature processed at a temperature of -30°C or lower. More specifically, when the voltage of the battery is 3 to 3.5V, the battery can be low-temperature processed at a temperature of -50°C or lower. In this way, the battery has the advantage that it can be safely crushed in the crushing process by performing low-temperature processing within a specific temperature range depending on the cell reference voltage of the battery.

[0041] By performing a low-temperature treatment on the battery within the aforementioned temperature range, the voltage remaining in minute quantities inside the battery, for example, a voltage of about 2V to 3V, drops to near 0V. Therefore, even if a short circuit occurs where the positive and negative electrodes come into direct contact, no battery reaction occurs, the battery temperature does not rise, and gas generation and combustion of the electrolyte do not occur. Furthermore, because the electrolyte is in a frozen state or in a state where vaporization is suppressed, the mobility of lithium ions is very low, the current-carrying characteristics due to lithium ion movement can be significantly reduced, and since vaporization of the electrolyte does not occur, flammable gases of ethylene, propylene, and hydrogen are not generated.

[0042] When the low-temperature treatment stage is carried out at a temperature higher than the temperature range, the voltage remaining inside the battery does not drop to 0V, and a battery reaction due to short-circuiting may occur. Since the electrolyte is not completely frozen, this is not appropriate. Thus, the battery treatment method has the advantage that it can prevent the risk of fire that may occur in the battery crushing crushing process process of crushing a battery such as a lithium secondary battery by including a stage of low-temperature treatment before crushing the battery.

[0043] In one embodiment, the stage of low-temperature treatment may include a stage of treating the battery for a minimum freezing time or more. The minimum freezing time can satisfy the following formula 2.

[0044] <Formula 2> Minimum freezing time = (1.55461 + (-0.06551 × target temperature) + (7.47E-5 × target temperature 2 )) × weight 0.32 ±0.45

[0045] (In the above formula 2, the target temperature means the target temperature (°C) for low-temperature treatment of the battery, and the weight means the weight (kg) of the battery)

[0046] The formula 2 means the minimum freezing time of the battery derived from the weight and freezing time of the battery. The formula 2 is that the minimum freezing time is (1.55461 + (-0.06551 × target temperature) + (7.47E-5 × target temperature 2 )) × weight 0.32 The lower limit value of -0.45 and (1.55461 + (-0.06551 × target temperature) + (7.47E-5 × target temperature 2 )) × weight 0.32 The upper limit value of +0.45 can be satisfied, and the time can be longer than the value of the formula 2 that satisfies the upper limit value and the lower limit value range.

[0047] If Equation 2 satisfies the aforementioned range, it is possible to improve economy and safety by considering the minimum freezing time when treating the battery at low temperature so that the battery can be stabilized before the battery crushing stage and safely crushed in the battery crushing stage. If Equation 2 does not satisfy the aforementioned range, there is a problem that the electrolyte inside the battery will not be properly frozen and stabilized.

[0048] In one embodiment, the step of chilling the battery can be performed for 2 hours or more. Specifically, if the battery is a module containing multiple cells, the freezing time for the module may be 10 hours or more. Specifically, the freezing time for the module may be 10 to 26 hours. The weight of the module may be 28 to 32 kg.

[0049] If the battery is a cell, the freezing time for the cell may be 2 hours or more. Specifically, it may be 3 hours or more, and more specifically, 3 to 12 hours. The weight of the cell may be 0.5 to 1.5 kg.

[0050] By performing the low-temperature treatment step on the battery for the aforementioned time, battery stabilization is easily achieved, and if the battery is to be crushed, it is possible to prevent a fire from occurring in the battery.

[0051] If the step of freezing the battery takes significantly longer than the aforementioned time, it becomes economically uneconomical. If the step of freezing the battery is performed for significantly less time than the aforementioned time, it becomes difficult to stabilize the battery.

[0052] The step of crushing the battery may mean a step of applying impact or pressure to the battery so that a part of the battery falls off. In one embodiment, the step of crushing the battery may mean a step of pulverizing the battery, a step of cutting the battery, a step of compressing the battery, and a combination thereof. Specifically, the crushing step may include all steps of destroying the battery to obtain small fragments.

[0053] In one embodiment, the step of crushing the battery may include all steps of compressing the frozen battery or destroying the battery by applying an external force such as a shear force or a tensile force. The step of crushing the battery may be carried out, for example, using a crusher.

[0054] In one embodiment, the step of crushing the battery can be performed at least once. Specifically, the crushing step can be performed at least once, either continuously or discontinuously. In one embodiment, the step of crushing the battery can be performed using a two-shaft, two-stage shredder.

[0055] In one embodiment, the battery crushing step can be carried out under conditions of supplying an inert gas, carbon dioxide, nitrogen, water, or a combination thereof, or under a vacuum atmosphere of 100 torr or less. For example, when the battery freezing step is carried out by cooling in a temperature range of -60 to -20°C, carrying it out under the aforementioned conditions can suppress oxygen supply, prevent the electrolyte from reacting with oxygen, prevent explosions, suppress the vaporization of the electrolyte, and prevent the generation of flammable gases such as ethylene, propylene, or hydrogen.

[0056] In one embodiment, the crushed battery material can satisfy the following condition 1 from the stage of crushing the battery.

[0057] <Condition 1> The aforementioned layered structure may be a laminated structure consisting of one to seven layers.

[0058] The battery shredder may have a layered structure having one to seven layers. Specifically, the layered structure may have one to five layers. By stacking the layered structure within the above range, the temperature rise of the shredder is minimized and the heating time is appropriate. If the layered structure is stacked thicker than the upper limit of the above range, the temperature rise increases excessively, the heating time also increases, and there is a problem of fire occurring due to combustion.

[0059] In one embodiment, the battery shredder can satisfy the following condition 2.

[0060] <Condition 2> The size of the crushed battery material may be 100 mm or less, based on the longest axis among the horizontal, vertical, and height directions.

[0061] In one embodiment, the battery shredder may have a size of 100 mm or less based on its long axis. Specifically, the size of the battery shredder may be 50 mm or less. If the size of the battery shredder is excessively large, there is a problem that the temperature of the battery shredder itself may rise to 100°C or higher, which could cause a fire. [Examples]

[0062] The following describes preferred embodiments and comparative examples of the present invention. However, the following embodiments are merely preferred embodiments of the present invention, and the present invention is not limited to these embodiments.

[0063] <Example of experiment> Battery preparation stage For an NCM622 lithium-ion battery with a state of charge (SOC) of 100%, batteries with cell reference voltages of 4, 3.5, 3, 2.5, 1.5, 1, 0.5, and 0V were prepared. The target battery voltage was matched through electrical discharge, with cell reference battery discharge set to 1-10A conditions, each for no more than 5 hours, and discharge was performed in stages from 3.5V to 0V. After discharge, the final target voltage was set to the voltage rebounded over 24 hours, and the batteries were prepared.

[0064] Table 1 below shows the amperage based on the battery voltage.

[0065] [Table 1]

[0066] Cryogenic treatment stage To determine when the sample temperature equaled the freezer temperature, the sample was connected to a thermometer (Thermo Couple, TC), and then frozen to confirm the completion of the freezing process.

[0067] The stage of crushing the battery The batteries that underwent the aforementioned cryogenic treatment were shredded to a particle size range of 5 to 80 mm using a twin-shaft, two-stage shredder. The shredding was completed within 5 minutes for modules and within 3 minutes for cells.

[0068] Figures 2a and 2b show that ignition occurs from the battery during the crushing stage of the present invention.

[0069] Figure 2a shows that ignition occurs from the battery during battery crushing, and Figure 2b shows that ignition occurs from the crushed battery material after battery crushing. Thus, referring to Figures 2a and 2b, it is clear that batteries contain flammable materials such as electrolyte, and when a predetermined external force is applied to the battery, the activation energy is maximized, causing the battery to ignite. This necessitates a low-temperature treatment step to stabilize the flammable materials inside the battery.

[0070] Figures 3a and 3b show the temperatures of the crusher and the crushed material measured during the crushing stage of the present invention.

[0071] Figure 3a shows the internal temperature of the crusher, and Figure 3b shows the temperature of the crushed material. By measuring the internal temperature of the crusher and the temperature of the crushed material, it is possible to check whether or not the battery has ignited.

[0072] <Evaluation Example 1>: Derivation of the optimal temperature range by voltage The low-temperature treatment of the battery was used to prevent the evaporation of the electrolyte, and it was confirmed that the amount of temperature rise after crushing varied depending on the voltage remaining in the battery. Therefore, the battery voltage was measured cell by cell, and the low-temperature treatment temperature was determined based on this voltage.

[0073] The voltage was measured by touching the terminals of a voltage measuring tester to the positive and negative terminals of the battery. The presence or absence of a fire was determined by visual inspection and by installing thermal imaging cameras inside the crusher and in the crushed material collection box to observe the temperature changes inside the crusher and the crushed material during crushing. If a fire occurred, a circle (○) was displayed, and if no fire occurred, a cross (×) was displayed.

[0074] Table 2 below shows whether or not a fire occurred during cryogenic processing using voltage.

[0075] [Table 2]

[0076] Referring to Table 2 above, we can see that when the battery is cryogenically treated at a temperature lower than the value of Equation 1, no fire occurs during the battery crushing process. Specifically, we confirmed that no fire occurs when the battery is cryogenically treated at a temperature lower than the upper and lower limits of Equation 1.

[0077] <Evaluation Example 2>: Minimum freezing time by weight and freezing temperature Figure 4 shows the required freezing time depending on the module temperature.

[0078] Referring to Figure 4, the approximately 30kg module's temperature decreased over time, and the battery underwent cryogenic treatment at -60°C for 24 hours. Specifically, the graph shows the time required for the module's temperature to reach the refrigerator temperature of -60°C when the module was placed in a refrigerator set to -60°C. More specifically, this could also be the freezing time required to freeze the module to a target temperature.

[0079] Table 3 below shows the freezing time at different temperatures based on the weight of the modules and cells.

[0080] [Table 3]

[0081] Referring to Table 2 above, it was confirmed that when a 30kg module, one 1kg cell, or three 3kg cells are placed in a freezer at a set temperature, hazardous substances such as the electrolyte inside the battery stabilize when the battery is frozen for a time longer than the minimum freezing time required to reach the set freezer temperature (Equation 2). Specifically, it was confirmed that when a 30kg module is placed in a freezer at -40°C, it takes more than 13 hours of cooling to reach the target temperature of -40°C, the same as the freezer temperature. Specifically, it was confirmed that when the battery is cooled for a time shorter than the minimum freezing time required to reach the target temperature (below the lower and upper limits of Equation 2), the battery temperature does not reach the target temperature of the freezer.

[0082] Conversely, it was confirmed that when the battery was cooled for a time longer than the range of the lower limit to the upper limit of Equation 2, it was set to the same temperature as the set target temperature, which is the temperature of the freezer. In this way, the minimum cooling time based on the weight of the battery can be derived, and the battery can be efficiently stabilized before the battery crushing process, preventing problems such as fire from occurring.

[0083] Although preferred embodiments have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concepts defined in the following claims also fall within the scope of the present invention.

Claims

1. This concerns methods for disposing of used batteries. Preparing the battery; A step of measuring the voltage of the aforementioned battery; A step of performing a low-temperature treatment on the battery at a temperature below the minimum temperature using the voltage of the battery; and The step includes crushing the aforementioned battery, The battery processing method wherein the minimum temperature satisfies the following equation 1. <Formula 1> Minimum temperature = 21.42857 + (-21.1255) × voltage + (-0.69264) × voltage ２ ±0.5 (In equation 1 above, voltage refers to the battery voltage.)

2. The battery processing method according to claim 1, wherein the voltage of the battery measured in the step of measuring the voltage of the battery is 0 to 4.2V relative to the cell.

3. The battery processing method according to claim 1, wherein the step of low-temperature processing involves processing the battery at 10°C or below.

4. The aforementioned low-temperature processing step involves processing the battery for a minimum freezing time or longer. The battery processing method according to claim 1, wherein the minimum freezing time satisfies the following formula 2. <Formula 2> Minimum freezing time = (1.55461 + (-0.06551 × target temperature) + (7.47E-5 × target temperature) ２ )) x weight ０．３２ ±0.45 (In equation 2 above, target temperature refers to the target temperature (°C) for low-temperature processing of the battery, and weight refers to the weight of the battery (kg).)

5. In the step of performing a low-temperature treatment on the battery using the battery's voltage for a minimum freezing time or longer, When the battery is a module having multiple cells, The battery processing method according to claim 1, wherein the freezing time of the battery is 10 hours or more.

6. The battery processing method according to claim 5, wherein the module has a weight of 28 to 32 kg.

7. In the step of performing a low-temperature treatment on the battery using the battery's voltage for a minimum freezing time or longer, When the aforementioned battery is a cell, The battery processing method according to claim 1, wherein the freezing time of the battery is two hours or more.

8. The battery processing method according to claim 7, wherein the cell has a weight of 0.5 to 1.5 kg.

9. The battery processing method according to claim 1, wherein the step of crushing the battery is to crush the battery into particles in the particle size range of 5 to 80 mm.

10. The battery processing method according to claim 1, wherein the step of crushing the battery is performed by crushing it with a two-shaft, two-stage shredder.

11. The battery processing method according to claim 1, wherein the step of measuring the voltage of the battery includes a step of reducing the voltage of the battery.

12. The battery processing method according to claim 1, wherein the battery shredded material obtained after the step of crushing the battery satisfies either condition 1 or condition 2 below. <Condition 1> The layered structure can be a stacked structure consisting of one to seven layers. <Condition 2> The size of the crushed battery material may be 100 mm or less, based on the longest axis among the horizontal, vertical, and height directions.

Images