Method of disposing battery

Abstract

The present invention relates to a method of disposing a battery and to a method of disposing a waste battery, comprising the steps of: preparing a battery; measuring the voltage of the battery; processing the battery at a low temperature equal to or lower than a minimum temperature according to the voltage of the battery; and shredding the battery, wherein the minimum temperature satisfies equation 1. <Equation 1> Minimum temperature = 21.42857 + (-21.1255) x voltage + (-0.69264) x voltage2 ± 0.5 (In equation 1, voltage means a cell reference voltage of the battery).

Description

How to dispose of batteries

[0001] It relates to waste batteries, and more specifically, to a method for crushing batteries recovered from waste batteries.

[0002] Battery technology is a key component of electric vehicles, where demand and supply are rapidly increasing due to environmental concerns. The disposal of waste batteries generated from these vehicles has become a social issue. These batteries for electric vehicles are rechargeable secondary batteries characterized by containing lithium. The core components of these batteries include a cathode material, an anode material, a current collector, an electrolyte, and a separator.

[0003] The raw materials for the positive electrode material are nickel, cobalt, and manganese oxides, while the raw material for the negative electrode material is carbon. Al and copper foil are used as the current collector. The battery is assembled into a pack for automotive applications by assemble- ing cells, the smallest unit, into a pack. This process involves the use of plastic cases, iron bolts, nuts, and frames. Among these, the valuable metals of lithium, nickel, cobalt, and manganese (Li), with the value of Li in particular having risen sharply in recent years, are attracting increasing attention. Consequently, there is growing interest in the recovery and recycling of these rare elements.

[0004] Even when automotive batteries reach the end of their lifespan, they can still be recycled for other applications. For example, these applications could be energy storage systems (ESS). After recycling these energy storage systems, the batteries are treated as waste batteries.

[0005] The process of recovering these used batteries typically involves disassembling, discharging, crushing, and heat treating the batteries to produce black mass, which is then refined through wet refining to be used as a raw material for cathode materials. However, due to the risk of fire and explosion during the battery crushing process, various methods for safe crushing are being studied.

[0006] A common method for safely dismantling batteries is hydrodisintegration using water or brine. However, this requires cell-by-cell disassembly and additional processing to allow the solution to penetrate the cells. This process is labor-intensive and generates wastewater, making it unfriendly to the environment. Furthermore, the use of brine can contaminate elements such as Na, Cl, K, and Mg.

[0007] Accordingly, interest in safe and environmentally friendly battery disposal methods is growing as a first step toward recycling waste batteries.

[0008] The technical problem to be solved by the present invention is to provide a battery processing method that safely crushes waste batteries.

[0009] According to one embodiment of the present invention, a method for processing a battery is provided, which comprises a step of preparing a battery, a step of measuring a voltage of the battery, a step of low-temperature processing the battery at a temperature below a minimum temperature according to the voltage of the battery, and a step of crushing the battery, wherein the minimum temperature satisfies the following equation 1.

[0010] <Formula 1>

[0011] Minimum temperature = (21.42857 + (-21.1255) × voltage + (-0.69264) × voltage 2 ) ± 0.5

[0012] (In the above equation 1, voltage refers to the voltage of the battery)

[0013] In one embodiment, the voltage of the battery measured in the step of measuring the voltage of the battery may be 0 to 4.2 V on a cell basis. In one embodiment, the step of low-temperature processing may process the battery at 10° C. or lower.

[0014] In one embodiment, the low-temperature treatment step treats the battery for a minimum freezing time or longer,

[0015] The above minimum freezing time can satisfy the following equation 2.

[0016] <Formula 2>

[0017] Minimum freezing time = (1.55461 + (-0.06551 × target temperature) + (7.47E -5 × target temperature) 2 )) × Weight 0.32 ± 0.45

[0018] (In the above formula 2, the target temperature means the target temperature (℃) for low-temperature treatment of the battery, and the weight means the weight of the battery (kg))

[0019] In one embodiment, in the step of low-temperature-treating the battery for a minimum freezing time or longer depending on the voltage of the battery, when the battery is a module having a plurality of cells, the freezing completion time of the battery may be 10 hours or longer. In one embodiment, the module may have a weight of 28 to 32 kg.

[0020] In one embodiment, in the step of low-temperature-treating the battery for a minimum freezing time or longer depending on the voltage of the battery, when the battery is a cell, the freezing completion time of the battery may be 2 hours or longer. In one embodiment, the cell may have a weight of 0.5 to 1.5 kg.

[0021] In one embodiment, the step of shredding the battery may shred the battery into particles of 5 to 80 mm in size. In one embodiment, the step of shredding the battery may be performed using a two-axis, two-stage shredder.

[0022] In one embodiment, the step of measuring the voltage of the battery may include a step of reducing the voltage of the battery. In one embodiment, the battery shreds obtained by the step of shredding the battery may satisfy the following condition 1 or condition 2.

[0023] Condition 1

[0024] The above layered structure may be a laminated structure having 1 or more layers and 7 or fewer layers.

[0025] Condition 2

[0026] The size of the above battery shreds may be 100 mm or less based on the longest axis among the length, width, and height directions.

[0027] According to one embodiment of the present invention, a battery processing method provides a processing method for safely crushing a battery by controlling a minimum cooling temperature according to the voltage of a cell in the battery.

[0028] FIGS. 1A and 1B are photographs of battery shreds according to one embodiment of the present invention.

[0029] Figures 2a and 2b illustrate that ignition occurs from a battery during the shredding step of the present invention.

[0030] Figures 3a and 3b show the temperatures of the crusher and the crushed material measured in the crushing step of the present invention.

[0031] Figure 4 shows the cooling time according to the temperature of the module.

[0032] The terms first, second, and third, etc., are used to describe, but are not limited to, various parts, components, regions, layers, and / or sections. These terms are used solely to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Accordingly, a first part, component, region, layer, or section described below may be referred to as a second part, component, region, layer, or section without departing from the scope of the present invention.

[0033] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used herein, the singular forms "singular" and "comprising" include plural forms as well, unless the context clearly dictates otherwise. The word "comprising" as used herein specifies a particular feature, region, integer, step, operation, element, and / or component, but does not exclude the presence or addition of other features, regions, integers, steps, operations, elements, and / or components.

[0034] When a part is referred to as being "on" or "over" another part, it can be directly on or over the other part, or there may be other parts intervening. Conversely, when a part is referred to as being "directly on" another part, there are no other parts intervening.

[0035] Although not defined otherwise, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or overly formal unless otherwise defined.

[0036] Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and the present invention is not limited thereto, and the present invention is defined solely by the scope of the claims set forth below.

[0037] According to one embodiment of the present invention, a battery processing method may be a method for processing a waste battery. Specifically, the method includes the steps of preparing a battery, measuring the voltage of the battery, performing a low-temperature treatment on the battery at a temperature below a minimum temperature depending on the voltage of the battery, and crushing the battery. Specifically, the battery processing method of the present invention may be a method for safely processing a battery without causing a fire when crushing the battery by performing a low-temperature treatment process above the minimum freezing temperature depending on the voltage of the battery.

[0038] In the step of preparing a battery, the battery may be, for example, a lithium secondary battery separated from an automobile, a secondary battery separated from an electronic device such as a mobile phone, a camera, or a laptop, specifically, a lithium secondary battery. Specifically, the battery may be a used battery whose lifespan has ended. The battery may have a voltage of about 4.5 V under a 100% SOC condition. The battery of the present invention may have a voltage of 2.0 to 4.5 V. Specifically, the voltage may be 2.5 to 4.0 V, and more specifically, 3.0 to 4.0 V.

[0039] The step of measuring the voltage of the battery may be a step of measuring the voltage of the battery. For example, the voltage of the battery may be a step of measuring the voltage of a module, a pack, or a cell. Specifically, 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 contacting the terminals of the battery according to the positive and negative poles using a general tester. 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 with the minimum freezing time described below.

[0040] In one embodiment, the voltage of the battery measured in the step of measuring the voltage of the battery may be 0 to 4.2 V on a cell basis. Specifically, the waste battery may have a voltage of about 4.2 V under a 100% SOC condition, and thus, a voltage lower than 4.2 V may be measured.

[0041] In one embodiment, the step of measuring the voltage of the battery may include the step of reducing the voltage of the battery. Specifically, the voltage of the battery may be controlled to a voltage of 0 to 4.2 V based on the cells within the battery. The step of reducing the voltage of the battery may control the voltage of the cells within the battery, for example, through electrical discharge.

[0042] The step of low-temperature-treating the battery at a temperature below a minimum temperature, depending on the voltage of the battery, may be a step of freezing and stabilizing the electrolyte contained within the battery. By treating the battery at a temperature below the minimum temperature, a fire caused by hazardous substances such as the electrolyte can be prevented when the battery is shredded.

[0043] In one embodiment, the minimum temperature may satisfy Equation 1 below.

[0044] <Formula 1>

[0045] Minimum Temperature = 21.42857 + (-21.1255) × Voltage + (-0.69264) × Voltage 2 ± 0.5

[0046] (In the above equation 1, voltage refers to the battery cell reference voltage (V))

[0047] The above equation 1 means the minimum cooling temperature according to the cell reference voltage of the battery in the battery low temperature treatment stage. The above equation 1 is 21.42857 + (-21.1255) × voltage + (-0.69264) × voltage. 2 - Lower limit of 0.5 and 21.42857 + (-21.1255) × voltage + (-0.69264) × voltage 2 + 0.5 has an upper limit, and a low-temperature treatment step can be performed at a temperature below the lower limit and upper limit range of the above formula 1 in the battery low-temperature treatment step.

[0048] By satisfying Equation 1 above, low-temperature treatment of a battery having a specific voltage can be easily performed, thereby minimizing the occurrence of battery fire during the shredding stage. If the battery temperature treatment is performed outside the range specified in Equation 1 above, stabilization of the battery having a specific voltage may not be achieved smoothly, which may lead to problems such as fire when the battery is shredded.

[0049] In one embodiment, the low-temperature treatment step may be a step of treating the battery at 10° C. or lower. Specifically, the low-temperature treatment step may be performed at a temperature of 0° C. or lower when the voltage of the battery is 1.0 V 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. Even more specifically, when the voltage of the battery is about 2.5 V, the battery may be low-temperature treated at a temperature of -30° C. or lower. Even 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. In this way, the battery has the advantage of being able to be safely crushed in the crushing process by performing low-temperature treatment in a specific temperature range depending on the cell reference voltage of the battery.

[0050] By performing the step of low-temperature processing of the battery in the above temperature range, the voltage remaining slightly inside the battery, for example, about 2 V to 3 V, is lowered to close to 0 V, and even if a short circuit occurs in which the positive and negative electrodes are in direct contact, no battery reaction occurs, so the battery temperature does not increase, and gas generation and combustion of the electrolyte do not occur. In addition, since the electrolyte is in a frozen state or in a state in which vaporization is suppressed, the mobility of lithium ions is very low, so that the conduction characteristics according 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.

[0051] If the above low-temperature treatment step is performed at a temperature higher than the above temperature range, the voltage remaining inside the battery may not be reduced to 0 V, which may cause a battery reaction due to a short circuit, and the electrolyte may not be completely frozen, which is not appropriate. In this way, the battery treatment method has the advantage of preventing the risk of fire that may occur during the battery crushing process by including a low-temperature treatment step before crushing a battery such as a lithium secondary battery.

[0052] In one embodiment, the low-temperature treatment step may include treating the battery for a minimum freezing time or longer. The minimum freezing time may satisfy Equation 2 below.

[0053] <Formula 2>

[0054] Minimum freezing time = (1.55461 + (-0.06551 × target temperature) + (7.47E -5 × target temperature) 2 )) × Weight 0.32 ± 0.45

[0055] (In the above formula 2, the target temperature means the target temperature (℃) for low-temperature treatment of the battery, and the weight means the weight of the battery (kg))

[0056]

[0057] The above equation 2 means the minimum freezing time of the battery derived according to the weight of the battery and the freezing time. The above equation 2 shows that the minimum freezing time is (1.55461 + (-0.06551 × target temperature) + (7.47E - 5 × target temperature) 2 )) × Weight 0.32 - Lower limit of 0.45 and (1.55461+(-0.06551 × target temperature) + (7.47E - 5×target temperature 2 )) × Weight 0.32 + It can satisfy the range of the upper limit value of 0.45, and can be performed for a time longer than the value of the above formula 2 that satisfies the range of the upper limit value and the lower limit value.

[0058] As the above equation 2 satisfies the aforementioned range, the battery can be stabilized prior to the battery shredding step, and the minimum freezing time can be considered when low-temperature processing the battery to ensure safe shredding during the battery shredding step, thereby improving economic efficiency and safety. If the above equation 2 does not satisfy the aforementioned range, there is a problem in which the electrolyte within the battery is not properly frozen and stabilized.

[0059] In one embodiment, the step of cold-treating the battery may be performed for at least 2 hours. Specifically, if the battery is a module comprising multiple cells, the freezing completion time of the module may be at least 10 hours. Specifically, the freezing completion time of the module may be between 10 and 26 hours. The module may weigh between 28 and 32 kg.

[0060] If the battery is a cell, the freezing completion time of the cell may be 2 hours or longer. Specifically, it may be 3 hours or longer, and more specifically, it may be performed for 3 to 12 hours. The weight of the cell may be 0.5 to 1.5 kg.

[0061] As the step of low-temperature treatment of the battery is performed for the aforementioned time, battery stabilization is easily achieved, and when the battery is shredded, a fire can be prevented from occurring from the battery.

[0062] If the step of freezing the battery takes excessively longer than the above time, there is a problem of uneconomical operation. If the step of freezing the battery is performed for excessively shorter than the above time, there is a problem of difficulty in stabilizing the battery.

[0063] The step of shredding the battery may refer to a process of applying shock or pressure to the battery so that a portion of the battery detaches from the battery. In one embodiment, the step of shredding the battery may refer to a process of crushing the battery, a process of cutting the battery, a process of compressing the battery, or a combination thereof. Specifically, the step of shredding may include any process that destroys the battery to obtain small-sized shredded materials.

[0064] In one embodiment, the step of crushing the battery may include any process that destroys the battery by compressing the frozen battery or applying an external force, such as a shear force or a tensile force. The step of crushing the battery may be performed, for example, using a crusher.

[0065] In one embodiment, the step of shredding the battery may be performed at least once. Specifically, the step of shredding may be performed at least once, either continuously or discontinuously. In one embodiment, the step of shredding the battery may be performed using a two-axis, two-stage shredder.

[0066] In one embodiment, the step of crushing the battery can be performed 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 performed by cooling it in a temperature range of -60 to -20°C, when performed under the above-described conditions, the supply of oxygen can be suppressed, preventing the electrolyte from reacting with oxygen, thereby preventing an explosion caused by this, and the vaporization of the electrolyte can be suppressed, thereby preventing the generation of flammable gases such as ethylene, propylene, or hydrogen.

[0067] In one embodiment, the battery shredded material shredded from the step of shredding the battery may satisfy the following condition 1.

[0068] Condition 1

[0069] The above layered structure may be a laminated structure having 1 or more layers and 7 or fewer layers.

[0070] The above-mentioned battery shredder may have a layered structure having a laminated structure of one or more layers and no more than seven layers. Specifically, the layered structure may have a layered structure of one or more layers and no more than five layers. As the layered structure is laminated within the above range, the temperature rise of the shredder can be minimized and the heating time can be appropriately taken. If the layered structure is laminated thicker than the upper limit of the above range, the temperature rise excessively increases and the heating time also increases, which may cause a fire due to combustion.

[0071] In one embodiment, the battery shredder may satisfy the following condition 2.

[0072] Condition 2

[0073] The size of the above battery shreds may be 100 mm or less based on the longest axis among the length, width, and height directions.

[0074] In one embodiment, the battery shredder may have a size of 100 mm or less based on its longitudinal 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 high possibility that the temperature of the battery shredder itself may rise above 100°C, which may cause a fire.

[0075]

[0076] Hereinafter, preferred embodiments and comparative examples of the present invention are described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

[0077]

[0078] <Experimental Example>

[0079] Battery preparation stage

[0080] When the SOC is 100%, batteries with cell-based voltages of 4, 3.5, 3, 2.5, 1.5, 1, 0.5, and 0 V were prepared for an NCM622 lithium-ion battery having approximately 4.2 V. The target battery voltage was adjusted through electric discharge, and the cell-based battery discharge was set to not exceed 5 hours for each step under the conditions of 1 to 10 A, and the discharge was performed stepwise from 3.5 to 0 V. After discharge, the voltage that rebounded for 24 hours was used as the final target voltage, and the batteries were prepared.

[0081] Table 1 below shows the amperage according to the battery voltage.

[0082] Voltage (V) Ampere (A) 4.2~3.5103.5~3.053.0~0.530.5~01

[0083] Cryogenic treatment stage

[0084] To determine when the temperature of the sample became the same as that of the freezer, it was connected to a temperature measuring device (Thermo Couple, TC) and frozen to determine when freezing was complete.

[0085]

[0086] Steps to shred the battery

[0087] The batteries subjected to the above cryogenic treatment were shredded into particles of 5 to 80 mm in a two-axis, two-stage shredder. The shredding was completed within 5 minutes for the modules and within 3 minutes for the cells.

[0088] Figures 2a and 2b illustrate that ignition occurs from a battery during the shredding step of the present invention.

[0089] Figure 2a illustrates that a fire occurs from a battery during battery shredding, and Figure 2b illustrates that a fire occurs from the battery shreds after battery shredding. As such, referring to Figures 2a and 2b, the battery contains ignitable substances, such as electrolytes within the battery. Therefore, when a certain external force is applied to the battery, the activation energy is maximized, causing the battery to ignite. Accordingly, a low-temperature treatment step is required to stabilize the ignitable substances within the battery.

[0090] Figures 3a and 3b show the temperatures of the crusher and the crushed material measured in the crushing step of the present invention.

[0091] Figure 3a shows the temperature inside the crusher, and Figure 3b shows the temperature of the shredded material. By measuring the temperature inside the crusher and the temperature of the shredded material, it is possible to determine whether the battery has caught fire.

[0092]

[0093] <Evaluation Example 1>: Deriving the optimal temperature range according to voltage

[0094] Low-temperature treatment of batteries is used to prevent electrolyte vaporization. It was confirmed that the temperature rise after shredding varies depending on the remaining voltage within the battery. Accordingly, the battery voltage was measured cell by cell, and the low-temperature treatment temperature was determined based on this voltage.

[0095] The above voltage was measured by contacting the + and - terminals of the battery using a voltage measuring tester, and the occurrence of a fire was determined by visually judging the occurrence of a fire and by observing the temperature change inside the crusher and the crushed material during crushing using a thermal imaging camera installed inside the crusher and in the crushed material collection bin. If a fire occurred, it was marked with ○, and if no fire occurred, it was marked with ×.

[0096] Table 2 below shows whether fire occurs during cryogenic treatment according to voltage.

[0097] Temperature voltage equation 1 lower limit value equation 1 upper limit value equation 1 satisfaction status fire occurrence status Example 100 16.4285726.42857○× Example 0.55.6926615.69266○× Comparative example 1.0-5.389574.61043×○ Example 01.0-5.389574.61043○× Comparative example 1.5-16.81812-6.81812×○ Comparative example 2.0-28.59299-18.59299×○ Example-20 1.5-16.81812-6.81812○× Example 2.0-28.59299-18.59299○× Comparative example 2 .5-40.71418-30.71418×○Example-402.5-40.71418-30.71418○×Comparative Example3.0-53.18169-43.18169×○Comparative Example3.5-65.99552-55.99552×○Example-603.0-53.18169-43.18169○×Example3.5-65.99552-55.99552○×Comparative Example4.0-79.15567-69.15567×○Comparative Example-904.0-79.15567-69.15567×○Formula 1 Lower limit: 21.42857+(-21.1255)×Voltage+(-0.69264)×Voltage 2 -0.5 equation 1 upper limit: 21.42857+(-21.1255)×voltage+(-0.69264)×voltage 2 +0.5

[0098] Looking at Table 2 above, looking at the values ​​of Equation 1, which is an indicator of the minimum cooling temperature according to voltage, it was confirmed that when the battery was cryogenically treated at a temperature lower than the value of Equation 1, no fire occurred during the battery crushing process. Specifically, it was confirmed that when the battery was cryogenically treated at a temperature lower than the upper and lower limit values ​​of Equation 1, no fire occurred.

[0099] <Evaluation Example 2>: Minimum freezing time by freezing treatment temperature according to weight

[0100] Figure 4 shows the cooling time according to the temperature of the module.

[0101] Referring to Figure 4, a module weighing about 30 kg will have a lower temperature over time,

[0102] The above battery was cryogenically treated at -60°C for 24 hours. Specifically, this graph shows the time required for the module to reach the temperature of the freezer, which is -60°C, when the module was placed in a freezer set to -60°C. More specifically, this graph may represent the freezing time required to freeze the module to the target temperature.

[0103] Table 3 below shows the freezing time according to temperature and the weight of the module and cell.

[0104] Weight 30 kg (module) 1 kg (1 cell) 3 kg (3 cells) Target temperature Freezing time Formula 2 Lower limit value Formula 2 Upper limit value Formula 2 Satisfied Freezing time Formula 2 Lower limit value Formula 2 Upper limit value Formula 2 Satisfied Freezing time Formula 2 Lower limit value Formula 2 Upper limit value Formula 2 Satisfied 0 o C54.1665.066○21.1052.005○21.7602.660○3×1×1×-20 ℃98.1469.046○32.4453.345○43.6644.564○7×1×1×-40 ℃1312.30213.202○43.8454.745○65.6546.554○11×2×4×-60 ℃1716.63717.537○65.3046.204○87.7288.628○15×4×6×-90 ℃2423.47124.371○87.6068.506○1110.99911.899○22×6×9×Formula 2 Lower limit value: (1.55461+(-0.06551×target temperature)+(7.47E-5×target temperature) 2 ))*weight 0.32 -0.45 equation 2 upper limit: (1.55461+(-0.06551×target temperature)+(7.47E-5×target temperature) 2 ))*weight 0.32 +0.45

[0105] Looking at Table 2 above, when a 30 kg module, 1 1 kg cell, or 3 3 kg cells were placed in a freezer at a set temperature, it was confirmed that when the battery was frozen for a period of time longer than the range of Equation 2, which is the minimum freezing time required to reach the set freezer temperature, hazardous substances such as electrolytes in the battery were stabilized. Specifically, when a 30 kg module was placed in the freezer at -40°C, it was confirmed that it took more than 13 hours to reach the target temperature of -40°C, which is the same as the temperature of the freezer. Specifically, when the battery was cooled for a period of time lower than the lower and upper limits of Equation 2 for the minimum freezing time to reach the target temperature, it was confirmed that the temperature of the battery did not reach the target temperature of the freezer.

[0106] In contrast, when the battery was cooled for a period of time exceeding the lower and upper limits of Equation 2, it was confirmed that the temperature was set to the same temperature as the set target temperature of the freezer. Thus, by deriving a minimum cooling time based on the battery weight, the battery can be effectively stabilized before the battery shredding process, thereby preventing problems such as fire.

[0107]

[0108] Although the preferred embodiments have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made 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. Regarding the method of processing waste batteries, Steps to prepare the battery; A step of measuring the voltage of the above battery; A step of low-temperature processing the battery at a temperature below a minimum temperature according to the voltage of the battery; and Comprising the step of crushing the above battery, The above minimum temperature is a battery processing method satisfying the following equation 1. <Formula 1> Minimum Temperature = 21.42857 + (-21.1255) × Voltage + (-0.69264) × Voltage 2 ± 0.5 (In the above equation 1, voltage refers to the voltage of the battery) 2. In paragraph 1, A battery processing method wherein the voltage of the battery measured in the step of measuring the voltage of the battery is 0 to 4.2 V on a cell basis.

3. In paragraph 1, The above low-temperature treatment step is a battery treatment method in which the battery is treated at 10°C or lower.

4. In paragraph 1, The above low-temperature treatment step treats the battery for a minimum freezing time or longer, A battery processing method wherein the minimum freezing time satisfies the following equation 2. <Formula 2> Minimum freezing time = (1.55461+(-0.06551×target temperature)+(7.47E-5×target temperature) 2 )) × Weight 0.32 ±0.45 (In the above formula 2, the target temperature means the target temperature (℃) for low-temperature treatment of the battery, and the weight means the weight of the battery (kg)) 5. In paragraph 1, In the step of low-temperature processing of the above battery for a minimum freezing time according to the voltage of the above battery, When the above battery is a module having multiple cells, A battery treatment method wherein the freezing time of the above battery is 10 hours or more.

6. In paragraph 5, The above module is a battery processing method having a weight of 28 to 32 kg.

7. In paragraph 1, In the step of low-temperature processing of the above battery for a minimum freezing time according to the voltage of the above battery, When the above battery is a cell, A battery treatment method wherein the freezing time of the above battery is 2 hours or more.

8. In paragraph 7, A method for processing a battery, wherein the above cell has a weight of 0.5 to 1.5 kg.

9. In paragraph 1, The step of crushing the above battery is a battery processing method that crushes the above battery into particles having a particle size range of 5 to 80 mm.

10. In paragraph 1, The step of shredding the above battery is a battery processing method in which the battery is shredded using a two-axis, two-stage shredder.

11. In paragraph 1, A battery processing method, wherein the step of measuring the voltage of the battery includes a step of reducing the voltage of the battery.

12. In paragraph 1, A method for processing batteries, wherein the battery shreds obtained by the step of shredding the above batteries satisfy the following condition 1 or condition 2. <Condition 1> The above layered structure may be a laminated structure having 1 or more layers and 7 or fewer layers. <Condition 2> The size of the above battery shreds may be 100 mm or less based on the longest axis among the length, width, and height directions.

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