Battery stabilizer and battery stabilization system

Abstract

The present invention relates to a battery stabilizer and a battery stabilization system, and comprises: an input unit for inputting a sagger into which waste battery crushed material has been loaded; a transport unit for transporting the sagger into which the waste battery crushed material has been loaded; a first stabilization unit for stabilizing the waste battery crushed material at a temperature of 30°C or lower; a second stabilization unit for stabilizing, at a temperature of 30°C to 150°C, the waste battery crushed material that has passed through the first stabilization unit; and a discharge unit for discharging the stabilized waste battery crushed material, wherein the sagger includes a hot air inlet for supplying heat to the waste battery crushed material.

Description

Battery stabilization device and battery stabilization system

[0001] It relates to waste batteries, a battery stabilization device and a battery stabilization system.

[0002] As global demand for electric vehicles grows, the disposal of waste batteries generated from these vehicles is emerging as a social issue. Lithium secondary batteries, the primary raw material for these waste batteries, contain organic solvents, explosive materials, and heavy metals such as nickel, cobalt, manganese, and iron. However, nickel, cobalt, manganese, and lithium are valuable metals with high scarcity value. Therefore, the recovery and recycling processes for discarded lithium secondary batteries are emerging as a key research area.

[0003] Specifically, a lithium secondary battery is mainly composed of copper and aluminum used as a current collector, Li, Ni, Co, Mn containing oxides constituting a positive electrode material, and graphite used as an negative electrode material, and includes a separator separating the positive electrode material and the negative electrode material, and an electrolyte injected into the separator. The solvent and salt used as the electrolyte are mainly a mixture of carbonate organic substances such as ethylene carbonate and propylene carbonate, and LiPF6 is used as a representative salt.

[0004] In order to utilize the above-mentioned waste batteries, development is actively underway on a waste battery recycling process that crushes the waste batteries to produce intermediate materials such as waste battery shreds or black powder, and then recovers valuable metals through a post-process.

[0005] However, in the waste battery recycling process, the waste battery generally has a voltage in the range of 3.0 to 3.2 V in a fully discharged state per cell, although this voltage varies depending on the number of times the battery has been used or its condition, and has a voltage close to 4 V in a fully charged state. Therefore, in a module or pack in which tens to hundreds of cells are connected, the residual voltage has a considerable amount of energy, so when an external shock is applied to the waste battery to physically disassemble it, safety related to explosion or electric shock of the battery becomes a problem.

[0006] To prevent this, after disassembly, a hole is created in the battery and it is discharged in salt water. After the discharge is complete, the battery is shredded and subjected to high-temperature heat treatment to remove water and electrolyte.

[0007] At this time, the salt used in the brine discharge contains a large amount of substances such as Na, K, Cl, Mg, and Ca. Among the substances mentioned above, Cl in particular is partially removed during the high-temperature heat treatment process, but the black powder, which is a powder in the form of a mixture of Ni-Co-Mn-Li-O oxide and C obtained by further processing the shredded or shredded waste battery to remove Al, Cu, and a portion of the separator, contains impurities such as Na, K, and Mg, which causes a problem of reducing the recovery rate during the extraction process using acid leaching in the subsequent process of the battery recycling process.

[0008] In addition, research is needed on a stabilization system to stably remove electrolyte contained in the shredded material and transport it stably to the post-processing stage after shredding of the used batteries.

[0009] According to one embodiment of the present invention, a battery stabilization device is provided that stably removes electrolyte from waste battery shreds, thereby reducing the content of impurities and preventing fire.

[0010] According to one embodiment of the present invention, a battery stabilization system is provided that stably removes electrolyte from waste battery shreds, thereby reducing the content of impurities and preventing fire.

[0011] According to one embodiment of the present invention, a battery stabilization device includes an input unit for inputting a sagger into which waste battery shreds are input, a transport unit for transporting the sagger into which the waste battery shreds are input, a first stabilization unit for stabilizing the waste battery shreds at a temperature of 30°C or lower, a second stabilization unit for stabilizing the waste battery shreds that have passed through the first stabilization unit at a temperature of 30 to 150°C, and a discharge unit for discharging the stabilized waste battery shreds, wherein the sagger may include a hot air inlet for supplying heat to the waste battery shreds.

[0012] In one embodiment, the first stabilizing unit may include a compressor. In one embodiment, the first stabilizing unit may include at least one weight and temperature measuring unit for measuring the weight of the waste battery shredder.

[0013] In one embodiment, the weight and temperature measuring unit may include a first weight and temperature measuring unit disposed between the input port and the first stabilizing unit, a second weight and temperature measuring unit disposed between the first stabilizing unit and the second stabilizing unit, and a third weight and temperature measuring unit disposed between the second stabilizing unit and the discharge unit. In one embodiment, the second stabilizing unit may include an intermediate stabilizing unit and a high-temperature stabilizing unit, and the intermediate stabilizing unit may heat the waste battery shredder to a range of 30 to 120°C, and the high-temperature stabilizing unit may heat the waste battery shredder to a range of 120 to 150°C.

[0014] In one embodiment, the hot air inlet is arranged in the shape of a cylinder, a triangular prism, a square prism, or a polygonal prism, and can dissipate heat through the outer surface of the shape. In one embodiment, the hot air inlet includes a plurality of hot air inlets, and the spacing between the plurality of hot air inlets can be 35 to 45% of the horizontal length of the saga.

[0015] In one embodiment, the height of the hot air inlet may be 25% to 50% of the height of the saga. In one embodiment, the height of the hot air inlet may be 25% to 50% of the height of the saga.

[0016] In one embodiment, the saga may have an open upper surface structure. In one embodiment, the saga may include a housing that surrounds a side of the saga, and may include a mesh portion and a sealing portion positioned below the mesh portion.

[0017] According to another embodiment of the present invention, a battery stabilization treatment system may include a first step of controlling a tap density of waste battery shreds, a second step of measuring a first weight as an initial weight and a first temperature as an initial temperature of the waste battery shreds, a third step of stabilizing the waste battery shreds at a temperature of 30° C. or lower, a fourth step of measuring a second weight and a second temperature of the waste battery shreds that have undergone the third step, a fifth step of stabilizing the waste battery shreds that have undergone the fourth step at a temperature of 30 to 150° C., a sixth step of measuring a third weight and a third temperature of the waste battery shreds that have undergone the fifth step, and a seventh step of discharging the waste battery shreds that have undergone the sixth step.

[0018] In one embodiment, the first step is to reduce the tap density of the waste battery shredder to 200 to 1,400 kg / m. 3In one embodiment, when the first weight and the first temperature of the waste battery shredder measured in the second step and the second weight and the second temperature of the waste battery shredder measured in the fourth step satisfy the following equations 1 and 2, the fifth step can be performed.

[0019] <Formula 1>

[0020] 2nd weight - 1st weight ≤ 25%

[0021] <Formula 2>

[0022] Second temperature - First temperature ≤ 25 ℃

[0023] In one embodiment, when the second weight and the second temperature of the waste battery shredder measured in the fourth step and the third weight and the third temperature of the waste battery shredder measured in the sixth step satisfy the following equations 3 and 4, the seventh step may be performed.

[0024] <Formula 3>

[0025] 3rd weight - 2nd weight ≤ 10%

[0026] <Formula 4>

[0027] Third temperature - Second temperature ≤ 25 ℃

[0028] In one embodiment, the fifth step is performed by a multi-stage heat treatment, and the multi-stage heat treatment can be performed sequentially at temperatures of 30 to 120° C. and 120 to 150° C. In one embodiment, prior to the first step of controlling the tap density of the waste battery shredder, the unit waste battery shredder constituting the waste battery shredder can include a step of controlling the unit waste battery shredder constituting the waste battery shredder to satisfy the following conditions 1 and 2.

[0029] <Condition 1> The above layered structure is a laminated structure having 1 or more layers and 7 or fewer layers.

[0030] <Condition 2> The size of the unit waste battery shredder is 100 mm or less based on the longest axis among the horizontal, vertical, and height directions.

[0031] In one embodiment, prior to the first step, the method further comprises a step of freezing the waste battery shreds, wherein the freezing step may be performed by cooling to -150°C to -20°C.

[0032] According to one embodiment of the present invention, a battery stabilization device includes low-temperature and high-temperature stabilization units and at least one weight and temperature measuring unit to check the weight and temperature of waste battery shreds, thereby providing a battery stabilization device having a low impurity content and preventing fire.

[0033] According to another embodiment of the present invention, a battery stabilization system includes low-temperature and high-temperature stabilization steps, and provides a battery stabilization system that has a low impurity content and prevents fire by controlling the weight and temperature of waste battery shreds at each step.

[0034] FIG. 1A is a perspective view of a battery stabilization device according to one embodiment of the present invention, and FIG. 1B is a schematic diagram of a battery stabilization device according to one embodiment of the present invention.

[0035] Figure 2 illustrates a Sagger according to one embodiment of the present invention.

[0036] FIG. 3 is a flowchart of a battery stabilization system according to one embodiment of the present invention.

[0037] Figure 4 shows the change in voltage of a battery according to cooling temperature according to one embodiment of the present invention.

[0038] FIG. 5 is a graph showing the relationship between battery weight, external cooling temperature, and cooling time according to one embodiment of the present invention.

[0039] Figures 6a and 6b are photographs of an example according to the minimum cooling time of the present invention, and Figures 6c and 6d are photographs of a comparative example according to the minimum cooling time of the present invention.

[0040] Figure 7 is a graph of temperature over time of shredded material according to one embodiment of the present invention.

[0041] FIGS. 8A to 8C illustrate unit battery fragments according to one embodiment and a comparative example of the present invention.

[0042] Figures 9a to 9c are photographs showing the temperature measurement process of a waste battery and the temperature trend of the shredded material according to the SOC conditions.

[0043] Figure 10a shows the temperature trend of the shredded material over time, and Figure 10b is a graph showing the temperature increase trend of the shredded material according to the SOC % condition of the battery.

[0044] FIG. 11 is a graph showing the temperature of waste battery shreds over time in low-temperature stabilization, intermediate stage, and high-temperature stabilization stages according to one embodiment of the present invention.

[0045] Figure 12 is a graph showing the self-heating of battery shreds inside a transport vessel.

[0046] Figure 13 shows the temperature change of the crushed material when the heating temperature was controlled for each section for heat treatment in the high-temperature stabilization stage.

[0047] Figure 14 shows the weight reduction ratio (%) of the electrolyte in the shredded waste according to the heat treatment temperature of 150°C after high-temperature stabilization treatment of the shredded waste battery.

[0048] Figure 15 shows the temperature and weight reduction according to the tap density of the battery shredder.

[0049] Figure 16 shows a graph of the heating rate according to the spacing of hot air inlets.

[0050] Figure 17 shows a graph of temperature versus time according to the spacing of the hot air inlet and the spacing of the sealing part.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] FIG. 1A is a perspective view of a battery stabilization device according to one embodiment of the present invention, and FIG. 1B is a schematic diagram of a battery stabilization device according to one embodiment of the present invention.

[0057] Referring to FIGS. 1A and 1B, a battery stabilization device according to one embodiment is a device for stabilizing waste battery shreds, and may include an input unit, a transport unit, a first stabilization unit, a second stabilization unit, a weight and temperature measurement unit, and a discharge unit.

[0058] The inlet may be a component into which waste battery shredders are fed. The waste battery shredders may be the result of shredding waste batteries. By feeding the sagger containing the waste battery shredders through the inlet, the saggers can be fed into a battery stabilization device.

[0059] The transport unit may be a component for transporting the waste battery shredder into the saga within the battery stabilization device. The transport unit may be a component that guides the waste battery shredder containing the saga to be discharged through the first stabilization unit and the second stabilization unit to the discharge unit. The transport unit may be structured, for example, in the form of a conveyor belt.

[0060] The first stabilizing unit can stabilize the waste battery shreds at low temperatures. Specifically, the first stabilizing unit can stabilize the waste battery shreds by transporting the waste battery shreds while they are contained in the saga and applying hot air to the saga.

[0061] In one embodiment, the first stabilizer may include a first heater unit at the bottom. The first heater unit may supply heat to the bottom of the saga. Specifically, the first heater unit may supply hot air to the saga to heat the waste battery shreds placed within the saga.

[0062] Specifically, the first stabilizing unit can stabilize the waste battery shreds at a temperature of 30°C or lower. More specifically, the first stabilizing unit can be a member that self-heats and stabilizes the waste battery shreds. The first stabilizing unit can prevent a problem in which sudden heating occurs and a fire occurs when the SoC (State of Charge), which indicates the remaining capacity of the waste battery shreds, is 30% or higher.

[0063] In one embodiment, the first stabilizer may include a high-temperature air dryer for supplying air with minimal moisture. Specifically, the first stabilizer may be a component that supplies dry air from which moisture has been removed while maintaining a temperature of 5 to 20°C, specifically 5 to 15°C. Specifically, the heater may be a device that creates dry air.

[0064] In one embodiment, the first stabilizer may include a compressor. The compressor may be a screw compressor for producing dry air. In one embodiment, the compressor may produce a pressure of 10 bar or less.

[0065] In one embodiment, the first stabilizing unit may further include a first vibration unit. Specifically, the first vibration unit may be controlled to apply heat evenly to the battery shreds by vibrating and dispersing the battery shreds when the first stabilizing unit applies hot air to the battery shreds.

[0066] The second stabilizing unit can stabilize the waste battery shreds at high temperatures. Specifically, the second stabilizing unit can stabilize the waste battery shreds by transporting the waste battery shreds while they are contained in the saga, and applying hot air to the saga to volatilize the high-temperature volatile electrolyte that has not volatilized in the first stabilizing unit.

[0067] In one embodiment, the second stabilizer may include a second heater unit at the bottom. The second heater unit may supply heat to the bottom of the saga. Specifically, the second heater unit may supply hot air to the saga to heat the waste battery shreds placed within the saga.

[0068] More specifically, the second stabilizing member may be a member that stabilizes the waste battery shreds at a temperature of 30 to 150° C. The second stabilizing member heats the waste battery shreds in the aforementioned temperature range, thereby volatilizing the electrolyte within the waste battery shreds, thereby reducing the weight of the waste battery shreds and reducing the tap density.

[0069] In one embodiment, the second stabilizing unit may include an intermediate stabilizing unit and a high-temperature stabilizing unit. The intermediate stabilizing unit may be a step for heating the spent battery shreds at a lower temperature than the high-temperature stabilizing unit. In one embodiment, the intermediate stabilizing unit may be a member that performs stabilization of the spent battery shreds at a temperature of 30 to 120°C. By including the intermediate stabilizing unit, the second stabilizing unit can gradually increase the temperature of the spent battery shreds to stably volatilize the electrolyte within the spent battery shreds.

[0070] In one embodiment, the high-temperature stabilizing unit may be a member that stabilizes the waste battery shreds at a temperature of 120 to 150°C. As the high-temperature stabilizing unit is performed within the aforementioned range, high-temperature heat may be applied to the waste battery shreds that have been stabilized through the low-temperature stabilization treatment step to volatilize the remaining electrolyte.

[0071] In one embodiment, the second stabilizing unit may further include a second vibrating unit. Specifically, the first vibrating unit may be controlled to vibrate and disperse the battery shreds when the second stabilizing unit applies hot air to the battery shreds, thereby uniformly applying heat to the battery shreds.

[0072] In one embodiment, the first stabilizer and the second stabilizer may be arranged in a horizontal or stacked configuration. Specifically, the second stabilizer may be stacked over the first stabilizer, or may be arranged on the same line and subsequent to the first stabilizer.

[0073] In one embodiment, the first stabilizing unit and the second stabilizing unit may apply heat to the battery shreds placed within the saga as the saga moves. The weight and temperature measuring unit may be a member that measures the weight of the spent battery shreds. Specifically, the weight and temperature measuring unit may measure the weight and temperature of the spent battery shreds using devices such as a load cell, a TC, and a thermal imaging camera.

[0074] In one embodiment, the battery stabilization device may include a weight and temperature measuring unit. The weight and temperature measuring unit may include a first weight and temperature measuring unit positioned between the inlet and the first stabilizing unit, a second weight and temperature measuring unit positioned between the first stabilizing unit and the second stabilizing unit, and a third weight and temperature measuring unit positioned between the second stabilizing unit and the discharge unit.

[0075] The first weight and temperature measuring unit can measure the initial weight and tap density of the waste battery shredded material. The first weight and temperature measuring unit can measure the initial weight and tap density of the waste battery shredded material. Specifically, the first weight and temperature measuring unit may be a component that measures the initial weight and temperature of the waste battery shredded material to determine whether or not to proceed with the subsequent stabilization treatment.

[0076] The first weight and temperature measuring unit may be a member that determines whether the temperature of the waste battery shredder is -20 to 10°C and whether the weight of the waste battery shredder is similar to the weight of the waste battery before shredding. For example, the first weight and temperature measuring unit may be a member that determines whether the weight of the waste battery shredder is 31.75 to 32.25 kg.

[0077] When the temperature and weight of the waste battery shredder are within the aforementioned ranges, the waste battery shredder can be moved to the first stable section along the conveying section. When the temperature and weight of the waste battery shredder are outside the aforementioned ranges, particularly when the temperature decrease is large due to initial heat generation after shredding, the movement of the waste battery shredder to the first stable section can be prevented in consideration of problems such as the occurrence of fire in the waste battery shredder.

[0078] The second weight and temperature measuring unit may be a member that measures the temperature and weight of the waste battery shredded material that has passed through the first stabilizing unit. Specifically, the second weight and temperature measuring unit may be a member that determines whether the temperature of the waste battery shredded material that has passed through the first stabilizing unit is 10 to 35° C. and whether the weight of the waste battery shredded material is 30.65 to 31.15 kg. When the temperature and weight of the waste battery shredded material are within the above-described range, the waste battery shredded material may be moved to the second stabilizing unit along the transport unit. When the temperature and weight of the waste battery shredded material are outside the above-described range, the movement to the second stabilizing unit may be prevented in consideration of problems such as a fire outbreak in the waste battery shredded material.

[0079] The third weight and temperature measuring unit may be a member that measures the temperature and weight of the waste battery shredded material that has passed through the second stabilizing unit. Specifically, the third weight and temperature measuring unit may be a member that determines whether the temperature of the waste battery shredded material that has passed through the second stabilizing unit is 100°C or lower and whether the weight of the waste battery shredded material is 29.85 kg or lower. When the temperature and weight of the waste battery shredded material are within the above-mentioned range, the waste battery shredded material may be discharged through the discharge unit. When the temperature and weight of the waste battery shredded material are outside the above-mentioned range, the waste battery shredded material may be prevented from being discharged through the discharge unit in consideration of problems such as the occurrence of a fire.

[0080] The discharge unit may be a component through which the spent battery shreds, which have passed through the second stabilization unit, are discharged to a subsequent process. Specifically, the discharge unit may be a component through which the stabilized spent battery shreds are discharged to a subsequent process. More specifically, the discharge unit discharges the battery shreds to a subsequent process, and the receiving unit, which receives the shreds discharged by the battery shreds, may be returned to the shredder.

[0081] Figure 2 illustrates a Sagger according to one embodiment of the present invention.

[0082] Figure 2 illustrates a perspective view of a sagger according to one embodiment of the present invention. In one embodiment, the sagger may include at least one hot air inlet for supplying heat to the waste battery shredder from heaters disposed below the first and second stabilizers, and a housing for protecting the sagger. Specifically, the sagger may include at least one hot air inlet so that when heat is supplied from the heaters disposed in the first and second stabilizers, the heat is introduced into the sagger, thereby supplying heat to the waste battery shredder. The waste battery shredder may be stabilized by the heat supplied through the hot air inlet.

[0083] In one embodiment, the hot air inlet may be positioned in at least a portion of the sagger. Specifically, the hot air inlet may facilitate the supply of hot air into the sagger. In one embodiment, the heater unit may be positioned on a side of the sagger to supply heat from the edge of the waste battery shredder.

[0084] In one embodiment, the hot air inlet may be arranged in the shape of a cylinder, a triangular prism, a square prism, or a polygonal prism. The hot air inlet may dissipate heat through the outer surface of the aforementioned shape. The hot air inlet may have the aforementioned shape and may have a mesh structure. The mesh structure is in the form of a mesh and can assist in easily dissipating the heat input from the hot air inlet.

[0085] By supplying heat to the waste battery shredder from the hot air inlet, the electrolyte within the waste battery shredder can be evaporated, thereby stabilizing the waste battery shredder. In this way, by supplying hot air to the waste battery shredder, the waste battery shredder can be stabilized using a dry method.

[0086] In one embodiment, the hot air inlet may include a plurality of inlets. The hot air inlet may be arranged in a plurality of places within the saga to uniformly supply heat to the entire area where the waste battery shredders are arranged within the saga.

[0087] In one embodiment, the spacing (L2) between the hot air inlets may be 35 to 45% based on the horizontal length (L1) of the saga. Specifically, the spacing between the central regions of the hot air inlets may be 35 to 45% based on 100% of the length of the major axis when cut in cross-section based on the X-axis and Y-axis planes, which are horizontal planes for the saga.

[0088] When the spacing between the plurality of hot air inlets satisfies the aforementioned range, the heating rate within the saga is high, which has the advantage of supplying heat evenly to the battery shredder. When the spacing between the plurality of hot air inlets exceeds the aforementioned range, the heating rate within the saga is not high, which causes the problem of not being able to supply heat evenly to the battery shredder.

[0089] In one embodiment, the height (H2) of the hot air inlet may be 25% to 50% of the height (H1) of the saga. Specifically, it may be 30% to 40%. Since the height (H2) of the hot air inlet satisfies the above-described range based on the height (H1) of the saga, there is an advantage in that the battery shreds placed in the saga can be uniformly heated.

[0090] If the height (H2) of the hot air inlet exceeds the upper limit of the aforementioned range, the amount of battery shreds placed in the chamber decreases, resulting in lower efficiency and a problem in which excessive hot air is supplied to the battery shreds. If the height (H2) of the hot air inlet exceeds the lower limit of the aforementioned range, there is a problem in which heat is not supplied adequately to the battery shreds.

[0091] In one embodiment, the cross-sectional shape along the vertical plane of the hot air inlet can satisfy at least one of a triangle, a square, a circle, an ellipse, and a polygon. Specifically, the cross-sectional shape of the hot air inlet refers to a shape when the cross-section is cut based on the X-axis and Z-axis planes, which are the vertical planes of the saga. The cross-sectional shape along the vertical plane of the hot air inlet has various shapes, so that heat can be efficiently supplied to battery shreds having various shapes.

[0092] In one embodiment, the saga may have an opening shape on its upper surface. Specifically, the saga may have an open structure with an unsealed upper surface. By having an open structure on the upper surface of the saga, heat generated by the battery shreds can be discharged through the open structure.

[0093] In one embodiment, the housing of the saga may include a mesh portion in at least a portion of the housing. Specifically, the mesh portion has a mesh shape, allowing heat generated from the battery shreds to be easily dissipated. More specifically, at least one of the four sides surrounding the saga may include a mesh portion.

[0094] In one embodiment, the housing of the saga may include a sealing portion in at least a portion of the area. Specifically, the sealing portion is positioned below the mesh portion, thereby maintaining the efficiency of heat input from the hot air inlet.

[0095] In one embodiment, based on 100% of the height of the saga, the ratio of the sealing portion may be 30 to 80%, specifically, 35 to 70%, and more specifically, 60 to 70%. By satisfying the ratio of the sealing portion within the aforementioned range, the time required to reach the target temperature of the first stable portion or the second stable portion may be minimized. If the ratio of the sealing portion is outside the upper limit of the aforementioned range, the heat emitted from the battery shreds may not be easily discharged to the outside, thereby generating a load inside the device. If the ratio of the sealing portion is outside the lower limit of the aforementioned range, there is a problem in that the time required to reach the target temperature is increased, thereby lowering the efficiency of the process.

[0096] Referring to FIG. 3, according to one embodiment, a battery stabilization system includes a first step of controlling a tap density of waste battery shreds, a second step of measuring a first weight as an initial weight and a first temperature as an initial temperature of the waste battery shreds, a third step of stabilizing the waste battery shreds at a temperature of 30° C. or lower, a fourth step of measuring a second weight and a second temperature of the waste battery shreds that have undergone the third step, a fifth step of stabilizing the waste battery shreds that have undergone the fourth step at a temperature of 30 to 120° C., a sixth step of measuring a third weight and a third temperature of the waste battery shreds that have undergone the fifth step, and a seventh step of discharging the waste battery shreds that have undergone the sixth step.

[0097] The first step of controlling the tap density of the waste battery shredder is to control the tap density of the waste battery shredder to 200 to 1,400 kg / m. 3 It may be a step of controlling. Specifically, the tap density of the waste battery shredder may be set to 500 to 1,000 kg / m 3 It may be a step to control.

[0098] Tapped density usually refers to the apparent density obtained by mechanically tapping a measuring container containing a powder sample. Specifically, in order to determine the tapped density characteristics of the above-mentioned lithium-ion waste battery shredder, a commercial battery module consisting of about 30 cells weighing 30 kg was crushed with a crusher, placed in a case (volume: 0.4 m wide × 0.7 m long × 0.44 m high) manufactured to stabilize the shredder, and mechanically tapped to measure the apparent density. More specifically, the density (ρ = M / V) was obtained by dividing the battery weight (M, kg) by the case volume (V, m3). The tapped density of the above-mentioned unit waste battery shredder calculated by the above-mentioned method is 200 to 600 kg / m 3 Specifically, the tap density is 240 to 400 kg / m 3 It could be.

[0099] If the tap density exceeds the upper limit, there is a risk of fire due to the instantaneous generation of heat by the short circuit of the densely stacked pieces of shredded material, and there is a problem of reduced stabilization processing capacity due to the narrow space through which the electrolyte can escape to the outside. If the tap density exceeds the lower limit, there is a problem of many gaps being created between the shredded material and the material taking up a large volume, requiring an additional pressurization process to transport it to the subsequent process.

[0100] In one embodiment, prior to the first step of controlling the tap density of the waste battery shredder, the step of controlling the unit waste battery shredders constituting the waste battery shredders so as to satisfy the following conditions 1 and 2 may be included.

[0101] <Condition 1> The above layered structure is a laminated structure having 1 or more layers and 7 or fewer layers.

[0102] <Condition 2> The size of the unit waste battery shredder is 100 mm or less based on the longest axis among the horizontal, vertical, and height directions.

[0103] The unit waste battery shredder is intended for recovering valuable metals from waste batteries and has a layered structure including a separator with a positive electrode or a negative electrode laminated on at least one surface. Specifically, the layered structure may include a configuration in which the positive electrode or negative electrode is included on one or both surfaces of the separator based on the separator. More specifically, the number of layers of the layered structure may correspond to the number of separators.

[0104] The above layered structure includes, for example, any one of anode-separator-cathode, anode-separator, separator-anode, separator-cathode, and cathode-separator, and for example, anode-separator-cathode-separator-anode-separator-cathode may have a three-layered layered structure. Specifically, the unit waste battery shredder may have a predetermined thickness in the thickness direction as at least one or more layers are laminated.

[0105] The above condition 1 may mean that the layered structure of the unit waste battery shredder including a separator with a positive or negative electrode laminated on at least one side is controlled in the step of shredding into a layered structure of 1 or more layers and 7 or fewer layers.

[0106] In one embodiment, the layered structure may be a laminated structure having 1 to 7 layers. Specifically, the layered structure may be a laminated structure having 1 to 5 layers. As the layered structure is laminated within the above range, the temperature rise of the shredded material 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 combustion.

[0107] In one embodiment, the size of the unit waste battery shredded material, specifically, the longest axis among the horizontal, vertical, and height directions, may be controlled in the shredding step to be 100 mm or less, specifically 50 mm or less. If the maximum size of the waste battery shredded material is greater than 100 mm, the temperature of the heat generated due to instability as the waste battery shredded material is shredded may rise to a temperature range of 120°C, which is the average vaporization temperature of the electrolyte, and thus a problem in stability, such as a fire, may occur.

[0108] In one embodiment, in order to satisfy the above conditions 1 and 2, a step of crushing the waste battery may be included. Specifically, a step of controlling the proportion of the unit waste battery crushed material satisfying the above conditions 1 and 2 to be 90% or more, specifically 95% or more, of the total volume of the waste battery crushed material may be further included. Specifically, this may correspond to controlling the proportion of the unit waste battery crushed material having a laminated structure exceeding 7 layers to be 10% or less of the total volume of the waste battery crushed material. Specifically, the proportion of the unit waste battery crushed material having a laminated structure exceeding 7 layers may be controlled to be 5% or less of the total volume of the waste battery crushed material. By satisfying the above range, there is an advantage in that the occurrence of a fire can be prevented.

[0109] The step of shredding the waste 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 waste 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 can destroy the battery to obtain small-sized shredded materials.

[0110] 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.

[0111] In one embodiment, the step of crushing the battery may be performed at least once. Specifically, the step of crushing may be performed at least once, either continuously or discontinuously.

[0112] 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.

[0113] In one embodiment, the recovery time required to lower the temperature of the waste battery shreds to a range of 20 to 50°C in the shredding step may be 200 minutes or less. Specifically, the recovery time required to lower the temperature of the waste battery shreds to a range of 35 to 45°C may be 200 minutes or less.

[0114] The second step of measuring the first weight, which is the initial weight of the waste battery shredded material, and the first temperature, which is the initial temperature, may be a step of measuring the initial weight and initial temperature of the shredded waste battery shredded material. In the second step, the initial weight of the waste battery shredded material may be controlled to be 30.65 to 31.15 kg. In the second step, the initial temperature of the waste battery shredded material may be controlled to be 10 to 35°C.

[0115] In one embodiment, the surface of the unit waste battery shredder may include a combustion zone and a top zone. The combustion zone refers to an area where at least a portion of the surface of the unit waste battery shredder is burned, and the top zone refers to a top zone on the surface where there are no traces of combustion.

[0116] In one embodiment, the area ratio of the combustion portion to the top portion on the surface of the unit waste battery shredder may be 30% or less. By satisfying the area ratio of the combustion portion to the top portion to be 30% or less, the possibility of the unit waste battery shredder being burned and causing a fire can be prevented. If the area ratio of the combustion portion to the top portion exceeds 30%, there is a risk that the unit waste battery shredder will burn and cause a fire accompanied by smoke.

[0117] In one embodiment, on the surface of the unit waste battery shredder, the combustion portion may be positioned at an edge of the surface. The top portion may be positioned near the center of the surface of the unit waste battery shredder. The combustion portion refers to an area that exhibits a darker color compared to the top portion.

[0118] The waste battery shredder may include at least one of the aforementioned unit waste battery shredders. In one embodiment, the waste battery shredder may comprise at least one of the unit waste battery shredders in an amount of at least 90% of the total volume of the waste battery shredder. Specifically, the amount of the unit waste battery shredders may be at least 95% of the total volume of the waste battery shredder.

[0119] Specifically, the above-mentioned waste battery shredder may correspond to the content that the proportion of unit waste battery shredders having a laminated structure exceeding 7 layers may be 10% or less, specifically 5% or less, in the total volume of the waste battery shredder, or the proportion of at least one unit waste battery shredder having a size exceeding 100 mm in the long axis may be 10% or less, specifically 5% or less, in the total volume of the waste battery shredder.

[0120] In this way, the proportion of waste battery shreds having a layered structure exceeding 7 layers per unit volume within the total volume of waste battery shreds or the proportion of unit waste battery shreds having a size exceeding 100 mm in terms of the long axis satisfies the above range, thereby preventing fire from occurring.

[0121] In one embodiment, the waste battery shredder is recovered from a waste battery and includes impurities, which may include Na, Ca, Mg, and K in weight percent. The waste battery shredder may be a shredder residue or black powder produced through a process of recovering and crushing the waste battery, which is a pretreatment process of a waste battery recycling process.

[0122] The above-mentioned waste battery shredder may contain impurities such as Na, Ca, Mg, and K. The above-mentioned waste battery shredder can facilitate the extraction of Li, a valuable metal of the same group, in a subsequent process by reducing the content of the impurities.

[0123] According to one embodiment of the present invention, the waste battery shredder includes impurities, and the impurities may include, in wt%, Na: 0.4% or less (excluding 0%), Ca: 0.03% or less (excluding 0%), Mg: 0.02% or less, and K: 0.02% or less.

[0124] Below, the reasons for limiting the content of the above impurities are explained.

[0125] Na: 0.4 wt% or less (excluding 0%)

[0126] Sodium (Na) is a homologous element in the post-process of recovering valuable metals from the waste battery shreds. In the lithium hydroxide formation process, sodium partially reacts instead of lithium to form sodium hydroxide, which has the side effect of lowering the recovery of lithium or increasing the cost in the causticization process. The waste battery shreds may contain 0.4 wt% or less of sodium, and specifically, may contain 0.1 wt% or less of sodium.

[0127] When the above sodium is contained in an amount greater than the above range, there is a problem that the yield decreases in the process required to produce lithium carbonate as Na is a Group 1 element identical to Li in the crystallization process of Li dissolved in the solvent after the leaching process and solvent extraction process when Na increases.

[0128] Ca: 0.03 wt% or less (excluding 0%)

[0129] Calcium (Ca), like sodium, is an element that lowers the recovery rate of valuable metals in the post-process of recovering valuable metals from the waste battery shredder. Calcium is more reactive than aluminum when forming lithium aluminate, forming a lithium cassinate structure, thereby hindering the formation of lithium aluminate, which is advantageous for subsequent reactions, thereby lowering the final lithium recovery rate. The waste battery shredder may contain 0.03% or less of calcium, and specifically, may contain 0.02% or less of calcium by weight.

[0130] If the above calcium is contained in an amount greater than the above range, there is a problem that the yield and process time increase during the solid-liquid separation process, which is an impurity purification process after the leaching process, as Ca increases. In addition, if the content of the above calcium is excessively large, when nickel, cobalt, manganese hydroxide and lithium hydroxide, which are precursors, are synthesized to produce a cathode material, Li[NiCoMn] 1-x Ca x )]O2, the potassium forms a cathode oxide structure, which hinders the movement of lithium ions, resulting in a problem of reduced battery capacity.

[0131] Mg: 0.02 wt% or less

[0132] Magnesium (Mg) is an element that makes it difficult to separate solid and liquid phases during acid leaching in a metal recovery process. The waste battery shreds may contain magnesium in an amount of 0.02 wt% or less, specifically, 0.01 wt% or less.

[0133] If the magnesium content is higher than the above range, there is a problem of burdening the recovery process of nickel, cobalt, lithium, etc. In addition, if the magnesium content is excessively high, when producing a cathode material by synthesizing with precursors such as nickel, cobalt, manganese hydroxide, and lithium hydroxide, Li[NiCoMn] 1-x Mg x ) is synthesized with O2, forming a cathode oxide structure, which hinders the movement of lithium ions and reduces the capacity of the battery.

[0134] K: 0.02 wt % or less

[0135] Potassium (K), also a cognate element with lithium, acts to inhibit lithium from forming hydroxide compounds. The spent battery shreds may contain potassium in an amount of 0.02 wt% or less, specifically, 0.01 wt% or less. If potassium exceeds this range, it can cause a load on the causticization process, reducing the lithium recovery rate.

[0136] In one embodiment, prior to the first step, the waste battery may include a step of freezing. Specifically, the step of freezing the waste battery may satisfy the following equation 1.

[0137] <Formula 1>

[0138] Minimum cooling time (Hr) = A × (W 0.33 )

[0139] (A = 4 × e(-0.02×dT), W = battery weight (Kg), dT= │external cooling temperature - target temperature│, ││ represents the absolute value)

[0140] In the above equation 1, W represents the weight of the battery, for example, the weight of a battery pack, a single battery, or a combination thereof. The minimum cooling time refers to the external cooling temperature, which is the cooling temperature applied to the battery, for example, the target temperature for cooling the electrolyte within the battery.

[0141] The step of freezing the waste battery has the advantage of being performed for a period longer than the minimum cooling time, thereby cooling the electrolyte inside the battery, thereby allowing for stable subsequent processes. The step of freezing the waste battery has the disadvantage that if the battery is frozen for a period shorter than the minimum cooling time, the electrolyte may not be cooled, which may lead to a risk of fire during crushing.

[0142] The step of freezing the above-mentioned waste battery is performed at a temperature sufficient to freeze the electrolyte contained within the battery. Specifically, the freezing step may be performed at a temperature range of, for example, -150 to -20°C. More specifically, the temperature range may be -150 to -50°C, and even more specifically, -80 to -60°C.

[0143] When the above-mentioned waste battery is frozen in the above-mentioned temperature range, the voltage slightly remaining 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, a battery reaction does not occur, 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 may not be generated.

[0144] If the above freezing process is outside the above temperature range, for example, if it cools to a temperature higher than -60℃, the voltage remaining inside the battery will not be lowered to 0 V, so a battery reaction due to a short circuit may occur, and the electrolyte will not be completely frozen, which is not appropriate. In addition, if it is cooled to -150℃, the electrolyte is sufficiently frozen, and the voltage inside the battery will also be lowered to 0 V, so there is no need to lower the temperature below this. In this way, the battery processing method has the advantage of preventing the risk of fire that may occur during the battery crushing process by including a freezing step before crushing a battery such as a lithium secondary battery.

[0145] When the initial temperature and initial weight of the waste battery shredder are within the aforementioned ranges, the waste battery shredder can be moved to the first stable section along the transport section. When the temperature and weight of the waste battery shredder are outside the aforementioned ranges, the movement to the first stable section can be prevented in consideration of issues such as the occurrence of a fire in the waste battery shredder.

[0146] The above low-temperature stabilization treatment step may be a step of stabilizing the crushed waste battery fragments at a temperature of 30°C or lower. The third step of stabilizing the crushed waste battery fragments at a temperature of 30°C or lower may be a step of slowly transporting the crushed waste battery fragments at a low temperature while removing the electrolyte and transporting them.

[0147] Specifically, the low-temperature stabilization treatment step may be a step in which the shredded waste battery fragments self-heat and stabilize. More specifically, the self-heating of the fragments varies depending on the SoC (State of Charge) condition, which indicates the remaining capacity of the battery.

[0148] More specifically, when the SoC exceeds 30%, sudden overheating may occur, potentially leading to a fire. Therefore, the low-temperature stabilization step may be a preliminary step to stabilize the battery at a temperature below 10°C to minimize the aforementioned fire risk.

[0149] In one embodiment, the third step, which is a low-temperature stabilization step, may be performed for 6 to 24 hours. If the low-temperature stabilization treatment step exceeds the upper limit of the aforementioned time range, the fire risk is minimized, but there is a problem of a long manufacturing lead time and reduced productivity. If the low-temperature stabilization treatment step exceeds the lower limit of the aforementioned time range, the electrolyte may not be removed sufficiently safely, which may lead to a problem of a post-process fire.

[0150] The fourth step, which measures the second weight and second temperature of the waste battery shreds that have undergone the third step, is a step of measuring the weight and temperature of the waste battery shreds that have undergone the low-temperature stabilization step. The third step may be a step of determining whether the waste battery shreds that have undergone low-temperature stabilization are suitable for high-temperature stabilization.

[0151] In one embodiment, when the first weight and the first temperature of the waste battery shredded material measured in the second step and the second weight and the second temperature of the waste battery shredded material measured in the fourth step satisfy the following equations 1 and 2, the fifth step, which is a high-temperature stabilization step, can be performed.

[0152] <Formula 1>

[0153] 2nd weight - 1st weight ≤ 25%

[0154] <Formula 2>

[0155] Second temperature - First temperature ≤ 25 ℃

[0156]

[0157] The above equations 1 and 2 represent the weight reduction (%) and temperature difference between the low-temperature stabilization-treated waste battery shreds and the initial waste battery shreds. Specifically, the equation 1 represents the weight reduction after low-temperature stabilization, and the equation 2 represents the temperature difference before and after low-temperature stabilization.

[0158] When the above equations 1 and 2 are satisfied, the waste battery shredder has the advantage of not causing a fire and smoothly volatilizing the electrolyte even when performing the high-temperature stabilization step. When the above equations 1 and 2 are not satisfied, the waste battery shredder that has undergone the low-temperature stabilization step cannot perform the subsequent high-temperature stabilization step, and the fourth step, which is the low-temperature stabilization step, can be continued until the conditions of the equations 1 and 2 are satisfied.

[0159] The fifth step of stabilizing the spent battery shreds that have gone through the fourth step at a temperature of 30 to 150°C may be a high-temperature stabilization step of stabilizing the spent battery shreds at a temperature higher than the low-temperature stabilization step. Specifically, the high-temperature stabilization step may be a step of applying high-temperature heat to the spent battery shreds that have been stabilized through the low-temperature stabilization step to volatilize the electrolyte within the spent battery shreds.

[0160] In one embodiment, the fifth step may be performed as a multi-stage heat treatment. Specifically, the fifth step may include an intermediate stabilization step and a high-temperature stabilization step. The multi-stage heat treatment may be performed sequentially at temperatures ranging from 30 to 120°C and from 120 to 150°C.

[0161] In one embodiment, the intermediate stabilization step may be performed at a temperature higher than the low-temperature stabilization step and lower than the high-temperature stabilization step. In one embodiment, the intermediate stabilization step may be performed at a temperature between 30 and 120° C. In one embodiment, the intermediate stabilization step may be performed as a multi-stage heat treatment. The intermediate stabilization steps may be sequentially performed at temperatures between 30 and 60° C., between 60 and 90° C., and between 90 and 120° C.

[0162] In this way, by performing an intermediate stabilization treatment step prior to a high-temperature stabilization treatment step, the temperature of the waste battery shreds can be gradually increased to stably volatilize the electrolyte within the waste battery shreds.

[0163] In one embodiment, the high-temperature stabilization step may be performed at 120 to 150° C. Specifically, the high-temperature stabilization step may be a step of applying high-temperature heat to the spent battery shreds stabilized through the low-temperature stabilization step to volatilize the electrolyte within the spent battery shreds.

[0164] If the above-mentioned high-temperature stabilization step exceeds the upper limit of the aforementioned temperature range, there is a risk of fire. If the above-mentioned high-temperature stabilization step exceeds the lower limit of the aforementioned temperature range, there is a risk of the electrolyte within the waste battery shreds not being sufficiently volatilized.

[0165] In one embodiment, the high-temperature stabilization step may be performed for 5 to 12 hours. If the high-temperature stabilization step exceeds the upper limit of the aforementioned time range, increased manufacturing lead time may lead to productivity issues. If the high-temperature stabilization step exceeds the lower limit of the aforementioned time range, the electrolyte may not be sufficiently removed, potentially causing a fire in the subsequent process.

[0166] The sixth step, which measures the third weight and third temperature of the waste battery shreds that have undergone the fifth step, is a step for measuring the weight and temperature of the waste battery shreds that have undergone the high-temperature stabilization step. Specifically, the sixth step may be a step for determining whether the waste battery shreds that have undergone the high-temperature stabilization step are suitable for performing subsequent processes.

[0167] In one embodiment, when the second weight and the second temperature of the waste battery shredder measured in the fourth step and the third weight and the third temperature of the waste battery shredder measured in the sixth step satisfy the following equations 3 and 4, the seventh step may be performed.

[0168] <Formula 3>

[0169] 3rd weight - 2nd weight ≤ 10%

[0170] <Formula 4>

[0171] Third temperature - Second temperature ≤ 25 ℃

[0172]

[0173] The above equations 3 and 4 represent the weight reduction (%) and temperature difference between the spent battery shredded material that has undergone high-temperature stabilization and the spent battery shredded material before performing the high-temperature stabilization step. When equations 3 and 4 are satisfied, there is an advantage in that even if a subsequent process, such as a high-temperature reduction process, is performed in a volatilized state of the spent battery shredded material, a fire does not occur and the subsequent process can be performed with stability. When equations 3 and 4 are not satisfied, there is a problem in that a fire occurs due to the electrolyte in the spent battery shredded material during the subsequent process, making it difficult to perform the process. When equations 3 and 4 are not satisfied, the spent battery shredded material can continuously perform the 6th step, which is the high-temperature stabilization step, until equations 3 and 4 are satisfied.

[0174] The seventh step, which discharges the spent battery shreds that have undergone the sixth step, can be performed on the spent battery shreds that satisfy the aforementioned conditions. The spent battery shreds that have undergone the low-temperature and high-temperature stabilization steps can be discharged for use in subsequent processes, such as a reduction process.

[0175]

[0176] 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.

[0177]

[0178] <Experimental Example>

[0179] <Battery internal temperature according to minimum freezing time>

[0180] Figure 4 shows the change in voltage of a battery according to cooling temperature according to one embodiment of the present invention.

[0181] Referring to Fig. 4, when the battery voltage was measured while freezing the battery to -80°C, the battery pack showed almost the same voltage at a high temperature of about 40°C, room temperature, and up to -60°C, confirming that the battery characteristics were not lost. Next, when the temperature decreased from -60°C to -70°C, the voltage was confirmed to drop rapidly, becoming 0 V below -70°C. In this way, it was confirmed that a short circuit did not occur when the battery was frozen to -60 to -150°C.

[0182] FIG. 5 is a graph showing the relationship between battery weight, external cooling temperature, and cooling time according to one embodiment of the present invention.

[0183] Referring to FIG. 5, it can be confirmed that a battery processing method according to an embodiment of the present invention can derive a minimum cooling time for cooling a battery in the step of freezing a battery. Specifically, it can be confirmed that the minimum cooling time is related to the battery weight, the external cooling temperature, and the target temperature. Specifically, when the target temperature is set to -70°C and the battery weights are 2.5 kg (A), 10 kg (B), 20 kg (C), and 50 kg (D), the external cooling temperature and the minimum cooling time are shown. When cooling the battery, it can be confirmed that the electrolyte of the battery begins to cool after a predetermined period of time and the voltage becomes 0 V. Through this, it can be confirmed that a minimum maintenance time is required to sufficiently cool the inside, specifically the electrolyte, when cooling the battery.

[0184] Specifically, in a heat transfer situation for cooling where heat is lost to the outside, considering the specific heat of the battery itself, it can be confirmed that the battery weight and cooling time are required. Thus, the present invention can determine the minimum time required for cooling by using the external cooling temperature for refrigeration, the target temperature, and the battery weight.

[0185] Table 1 below lists the minimum cooling time based on battery weight and external cooling temperature.

[0186] Battery weight [kg] External cooling temperature [℃] Target temperature [℃] Formula 1 Minimum cooling Time[h]A_12.5-120-701.91.9A_22.5-100-702.92.9A_32.5-80-704.44.4B_110-120-703.13.1B_210-100-704.64.6B_310-80-707.0 7.0C_120-120-703.93.9C_220-100-705.85.8C_320-80-708.88.8D_150-120-705.35.3D_250-100-707.97.9D_350-80-7011.911.9

[0187] Looking at Table 1 above, it can be seen that the smaller the battery weight, the shorter the minimum cooling time required for the battery to be cooled. In addition, it can be seen that when the value of Equation 1 derived from the relationship according to the battery weight, external cooling temperature, and target temperature is cooled with the minimum cooling time, the battery, specifically, the electrolyte of the battery, is cooled. In addition, when the battery is cooled for a time longer than the value of Equation 1, a fire does not occur during the post-process, that is, the battery crushing process. Figures 6a and 6b are photographs of an embodiment according to the minimum cooling time of the present invention, and Figures 6c and 6d are photographs of a comparative example according to the minimum cooling time of the present invention.

[0188] Referring to Figures 6a and 6b, the fire occurrence status of shredded material was tested when the battery was frozen for a time shorter than the minimum cooling time required for cooling. In the experiment, when the battery weight was 25 kg, the external cooling temperature was -95°C, and the target freezing temperature was -70°C, the experiment was conducted for 5 hours, which is lower than the value of Equation 1 below, when the value of Equation 1 below was 7 hours.

[0189] <Formula 1>

[0190] Minimum cooling time = A × (W 0.33 )

[0191] (A = 4 × e(-0.02×dT), W = battery weight (Kg), dT= │external cooling temperature - target temperature│, ││ represents the absolute value)

[0192] Referring to Figures 6c and 6d, the fire occurrence status of shredded material was tested when the battery was frozen for a period exceeding the minimum freezing time required for cooling. The above experiment was conducted under the same battery weight, external cooling temperature, and minimum freezing time of 7 hours or more as shown in Table 2 below.

[0193] Table 2 below compares the fire occurrence status of the examples and comparative examples according to the same battery weight, external cooling temperature, and minimum freezing time according to 6a to 6d. The fire occurrence status was determined as "O" if fire occurrence was observed after crushing the battery, and "X" if not.

[0194] Battery weight [Kg] External cooling temperature [℃] Target temperature [℃] Formula 1 Actual cooling time [h] Fire occurrence Comparative example 25- 95- 707.05 O Example 25- 95- 707.07 X

[0195] Looking at Table 2 above, it can be seen that if the battery is cooled to a value lower than the value in Equation 1, which corresponds to the minimum cooling time, the electrolyte is not cooled, resulting in a fire after the battery is shredded. Thus, it can be confirmed that if the battery is cooled using the value in Equation 1 as the minimum cooling time, the shredded material can be reliably utilized without a fire after the battery is shredded.

[0196] <Battery Shredding Stage - Shredder Size>

[0197] Even if a frozen battery is shredded, the likelihood of a fire occurring during shredding is low. However, a potential difference will develop within the shredded material depending on the battery's state of charge. In the present invention, a standard for stabilizing the shredded material was established by measuring the temperature rise of the shredded material.

[0198]

[0199] Figure 7 is a graph of temperature over time of shredded material according to one embodiment of the present invention.

[0200] Referring to Figure 7, the temperature change over time was examined to determine the maximum ignition temperature based on 20 mm-sized shredded materials. Specifically, after shredding a battery that had undergone a freezing step, the temperature change over time was measured by placing 20 mm-sized shredded materials in the air and cooling them using air. For 20 mm-sized shredded materials, the maximum ignition temperature was confirmed to be approximately 65°C. This is lower than the average evaporation temperature of the electrolyte, which is 120°C.

[0201] Table 3 below shows the temperature increase amount measured according to the size of the shredded material.

[0202] Average shredded material size (mm) 110 20 50 100 150 Heating amount [℃] 30 50 65 90 110 140

[0203] Looking at Table 3 above, it can be confirmed that there is a difference in the re-heating temperature depending on the size of the crushed material, and it was confirmed that the average size of the crushed material should be crushed within 100 mm in the long axis, which is the longest axis among the horizontal, vertical, and height directions, as the stabilization temperature for process design. In addition, depending on the size of the crushed material, the crushed material needs time to be physically stabilized. As a method for stabilizing the crushed material, it is necessary to maintain it for a predetermined process time under conditions of a temperature lower than 120 ℃, or to maintain it for a predetermined process time in a state in which an inert gas is introduced to reduce contact with oxygen in the atmosphere.

[0204] In the present invention, the crushed material was maintained at a room temperature of 30°C for approximately 3 hours based on an average crushed material size of 20 mm, and at this time, it was confirmed that the increased temperature of the crushed material had dropped to the room temperature level.

[0205] For the above stabilization time, for fragments less than 100 mm, there is no problem if the holding time is within a few minutes, but for fragments greater than 100 mm, the stabilization time must be at least 3 hours.

[0206]

[0207] <Battery shredding stage - Shredder layer control stage of battery shredder>

[0208] When crushing is performed below the minimum freezing time of the crushed material, the crushed material does not undergo brittle fracture in an ultra-low temperature state, and thus the size of the crushed material increases, or the thickness of the crushed material increases due to the existence of multiple layers of positive and negative current collectors. As the layer thickness of the crushed material increases, there are problems in that the temperature rises significantly and the heating time takes a long time.

[0209] Table 4 below shows the temperature rise according to the layered structure in a unit battery shredder according to one embodiment of the present invention, measured using a thermal imaging camera.

[0210] Referring to Table 4 below, in the case of a layered structure, anode-separator-cathode means 1 layer, and when the shredded material is laminated in multiple layers, it is arranged in the order of anode-separator-cathode-separator-anode-separator-cathode... Specifically, it means that the separator structure is arranged in multiple layers between the anode or the cathode in the waste battery as a 1-layer structure. Specifically, the anode or cathode may be arranged on at least one side of the separator based on the separator.

[0211] In Table 4 below, the average size of the shredded material was evaluated as 20 mm, and the temperature of each layer of the shredded material after shredding was evaluated and the recovery time required to rise from the freezing temperature to the maximum temperature and then drop back down to 40°C was measured.

[0212] At this time, the size of the shredded material was measured based on the long axis among the long and short axes of the shredded material.

[0213] Layered structure Number of layers [Number of layers] Size of crushed material [mm] Maximum temperature [℃] Below 40 ℃ Recovery time [min] Note Experimental example 2 206 3 1 1 0 Example Experimental example 3 206 4 1 1 0 Example Experimental example 5 207 5 1 4 4 Example Experimental example 7 201 0 5 2 0 0 Example Experimental example 10 1 0 Combustion-comparative example

[0214] FIGS. 8A to 8C illustrate unit battery shredders according to one embodiment and a comparative example of the present invention. Referring to FIG. 8A, examples and comparative examples can be confirmed according to the shredder size and the number of layers of the layered structure of the unit battery shredders.

[0215] When examining the above FIG. 8a and Table 4 simultaneously, it was confirmed that when the number of layers of the layered structure was 3 or less, the temperature of the crushed material was stably maintained at 110°C or less, and when the number of layers was higher than 7, the temperature rose to a temperature higher than 105°C and combustion occurred because it reacted with the electrolyte.

[0216] Referring to Fig. 8b, the mixing ratio according to the weight ratio of the battery shreds can be confirmed. Specifically, the weight of the battery shreds with a layered structure of 7 layers or less (left side of Fig. 8b) was mixed at 905 g, and the weight of the battery shreds with a layered structure of more than 7 layers (right side of Fig. 8b) was mixed at 95 g.

[0217] It was confirmed that, for the battery shredders, if the size exceeds 100 mm for one layer, the maximum temperature rises to over 105°C, which increases the possibility of fire. In addition, it was confirmed that, even if the size is less than 100 mm, the possibility of fire increases when the number of layers in the layered structure is 10 or more, specifically, more than 7.

[0218] Table 5 below shows the possibility of fire occurrence according to the weight % ratio of the battery shredder of the present invention having a layered structure exceeding 7 layers.

[0219] 7th floor Excess weight ratio [%] Number of experiments [number of times] Frequency of fire occurrence [number of times] Fire occurrence Remarks Experimental example 2 Less than 100X - Experimental example 2 - 5100X - Experimental example 6 - 10101△ Smoke occurrence Experimental example 10 Exceeds 33O Fire occurrence

[0220] Looking at Table 5 above, as a result of measuring the frequency of fire occurrence in shredded material on multiple occasions in units of 1 kg cells, it was confirmed that fire occurrence rarely occurred even when the weight ratio of shredded material with a layered structure exceeding 7 layers was included and was less than 10% based on the total weight ratio. In addition, it was confirmed that fire occurred in all three experiments when the weight ratio of shredded material with a layered structure exceeding 7 layers was included and exceeded 10% based on the total weight ratio. At this time, it was confirmed that the ignition location of the fire started from a thick shredded material of 7 layers or more. In this way, it was confirmed that when the weight ratio of shredded material having a layered structure of more than 7 layers is included in the total weight of the shredded material, which is 10% or less, specifically 5% or less, the fire of the shredded material can be prevented, and it was confirmed that the frequency of fire occurrence increases when the shredded material having a layered structure of 7 layers or more or shredded material having a size larger than 100 mm is included in more than 10% of the total battery shredded material.

[0221] In addition, Table 6 below confirms whether smoke is generated according to the ratio of combustion traces on the surface of the shredded material according to one embodiment of the present invention.

[0222] Combustion area / normal area ratio [%] Smoke generation Remarks Experimental example 10X Example Experimental example 20X Example Experimental example 30X Example Experimental example 30 Exceeded O Comparative example

[0223] FIG. 8C illustrates a burnt area and a top area of ​​a surface of a unit battery shredded material according to an embodiment of the present invention. Referring to FIG. 8C, the surface of the unit battery shredded material can be identified as a top area without traces of combustion due to high temperature and a surface of the shredded material with traces of combustion due to high temperature. The burnt area is an area with traces of combustion due to high temperature, and may be specifically a rapidly heated area, and refers to an area that is darker in color compared to the top area, which is an unburned area. The burnt area appears to have mostly burned edges.

[0224] Looking at Figure 8c and Table 6 above, when there are almost no traces of combustion due to high temperature on the surface of the unit battery shredder or when the traces of combustion within the surface area are 30% or less, it was confirmed that no combustion occurred when evaluating the presence or absence of smoke generation. When the traces of combustion within the surface area exceeded 30%, it was confirmed that a fire accompanied by smoke occurred.

[0225]

[0226] <Battery Stabilization Stage: Temperature Trends of Shredded Material According to SOC Conditions of Waste Battery>

[0227] Figures 9a to 9c are photographs showing the temperature measurement process of a waste battery and the temperature trend of the shredded material according to the SOC conditions.

[0228] Figures 9a and 9b show the temperature measured before and after battery shredding, and Figure 8c shows the temperature trend of the shredded material according to the SOC condition of the spent battery. Referring to Figure 9a, in order to measure the temperature before the spent battery was shredded, a hole of about 30 mm was drilled in the center of the battery module, and a TC (Thermal Couple) was installed to measure the temperature. Referring to Figure 8b, in order to measure the temperature of the shredded material after the spent battery was shredded, a TC (Thermal Couple) was installed in the center of the shredded material to measure the temperature.

[0229] Referring to Fig. 9c, the temperature patterns measured at 0% and 30% SoC conditions of the battery are shown. The SoC stands for 'State of Charge' and refers to the state of charge of a lithium-ion battery. Specifically, to indicate the remaining capacity of the battery, the currently usable battery capacity is divided by the total capacity and expressed as a percentage (%). This graph was measured by installing a TC (Thermal Couple) at the center of the shredded material to measure the internal temperature after the battery was cryo-fractured.

[0230] Figure 10a shows the temperature trend of the shredded material over time, and Figure 10b is a graph showing the temperature increase trend of the shredded material according to the SOC % condition of the battery.

[0231] Referring to FIGS. 10A and 10B, it can be confirmed that the temperature rises by more than 10 degrees over time and then decreases. In addition, it was confirmed that the battery with SoC 0% was crushed in a frozen state, and the initial temperature started at about -60°C and increased to a maximum temperature of about 30°C, and the battery with SOC 30% was confirmed to increase to 60°C. Through this, it is necessary to confirm in advance the SOC status of the crushed material that is subjected to low-temperature stabilization treatment through self-heating during stabilization treatment. Specifically, it was confirmed that the maximum temperature trend according to the SOC condition was such that a fire occurred during stabilization treatment when it was 80% or higher.

[0232]

[0233] <Battery stabilization stage>

[0234] FIG. 11 is a graph showing the temperature of battery shreds over time in low-temperature stabilization, intermediate stage, and high-temperature stabilization stages according to one embodiment of the present invention.

[0235] Figure 11 is a graph showing the temperature of battery shreds when stabilization treatments were continuously performed for up to 24 hours in total, including low-temperature stabilization for up to 12 hours, intermediate stabilization for up to 12 hours, and high-temperature stabilization for up to 12 hours. It was confirmed that by performing the low-temperature stabilization process, followed by the intermediate and high-temperature stabilization steps, the battery shreds could be stabilized by preventing a rapid increase in temperature, thereby obtaining a stabilized battery.

[0236] Figure 12 illustrates the temperature changes in a transport container containing shredded battery waste with an SOC of 30% or less. Specifically, the ambient temperature in Figure 12 refers to the temperature of the transport container. During the low-temperature stabilization stage, the temperature inside the transport container increases due to the self-heating of the battery shredded battery waste during transport. At this time, it can be confirmed that the temperature of the battery shredded battery waste is preferably controlled to 30°C or lower during the low-temperature stabilization stage.

[0237] Figure 13 shows the temperature change of the crushed material when the heating temperature was controlled for each section for heat treatment in the high-temperature stabilization stage.

[0238] Referring to Figure 13, the crushed material that has undergone the low-temperature stabilization step undergoes a high-temperature stabilization treatment step. In the high-temperature reduction treatment step, the temperature is controlled by adjusting the power (%) of the heating device for each section (6 sections) for continuous heat treatment, thereby increasing the temperature of the crushed material, and thereby removing the electrolyte within the crushed material.

[0239]

[0240] <Temperature heating pattern of stabilized shredded material>

[0241] Figure 14 shows the weight reduction ratio (%) of the electrolyte in the shredded battery according to the heat treatment temperature of 150°C after high-temperature stabilization treatment of the shredded battery.

[0242] Referring to Fig. 14, when performing high-temperature stabilization treatment on a battery, the heat treatment temperature of the shredded material is changed, and the weight reduction ratio (%) of the electrolyte contained in the entire shredded material is shown to some extent depending on the temperature conditions. Specifically, when the battery shredded material subjected to high-temperature stabilization treatment was heated to 150°C, it was confirmed that the amount of electrolyte contained in the battery shredded material was reduced to approximately 65 wt% after the high-temperature stabilization treatment, when the total amount of electrolyte contained in the battery shredded material was 100 wt%. The battery shredded material subjected to the high-temperature stabilization treatment is a stabilized lithium-ion shredded material that can be safely processed for battery processing in subsequent processes such as primary sorting or dry high-temperature treatment.

[0243] Therefore, as a major characteristic of the crushed material stabilized after cryo-crushing, it was confirmed that the crushed material stabilized at low temperature was additionally stabilized at high temperature, and when the stabilized battery crushed material was heated at 150°C, the change in mass before and after heating was very low.

[0244]

[0245] <Tap density change>

[0246] Figure 15 shows the temperature and weight reduction according to the tap density of the battery shredder.

[0247] Referring to Figure 15, before performing low-temperature stabilization, the tap density of the crushed battery waste was 250, 350, 450, and 550 kg / m, respectively. 3 When the battery shredder has undergone the battery stabilization step of the present invention, the weight reduction amount is shown. When the tap density of the battery shredder is 550 kg / m 3 at 250 kg / m 3 When sequentially lowered, it was confirmed that a gap was formed within the battery shreds, facilitating the evaporation of the electrolyte and increasing the weight reduction compared to the weight of the electrolyte (100%) inside the battery.

[0248]

[0249] <Evaluation Example>: Data according to low-temperature stabilization and high-temperature stabilization conditions

[0250] Table 7 below shows the weight reduction amount and tap density of the unit battery shredder having a layered structure of seven layers and having a size of 20 mm based on the long axis, which is the longest axis among the horizontal, vertical, and height directions, when the unit battery shredder is subjected to low-temperature stabilization treatment and high-temperature stabilization treatment step conditions described in Table 7 below.

[0251] At this time, a multi-stage intermediate stabilization treatment step was performed between the low-temperature stabilization treatment step and the high-temperature stabilization treatment step, and the intermediate stabilization treatment steps were heat-treated continuously in the temperature ranges of 30 to 60, 60 to 90, and 90 to 120 ℃, respectively, and the high-temperature heat treatment time mentioned above was performed for 12 h including the intermediate stabilization treatment time.

[0252] The weight loss of the crushed material after the low-temperature stabilization treatment step and the high-temperature stabilization treatment step was measured using a weight measuring device.

[0253] Tap density was measured by crushing a commercial battery module (consisting of 30 cells) weighing approximately 30 kg using a crusher, placing it in a stabilized volume case (0.44 m wide × 0.7 m long × 0.5 m high), and mechanically tapping it to obtain the apparent density. Specifically, the density (ρ = M / V) is obtained by dividing the battery weight (M, kg) by the volume of the case (V, m3).

[0254] The weight loss ratio after reheating the shredded material was determined by reheating the unit battery shredded material that had gone through the high-temperature stabilization treatment step to 150 ℃ and then checking the weight loss ratio before and after heating.

[0255] Stability was indicated as × if a fire occurred during the battery crushing process, and ○ if no fire occurred.

[0256] Tap density [kg / m 3 ] Low-temperature stabilization treatment stage conditions Low-temperature stabilization treatment stage Weight reduction of crushed material after the low-temperature stabilization treatment stage [%] High-temperature stabilization treatment stage conditions High-temperature stabilization treatment stage Weight reduction of crushed material after the high-temperature stabilization treatment stage [%] Weight reduction ratio after reheating of crushed material [%] Stability Temperature [℃] Time [h] Temperature [℃] Time [h] Example 250 10 6 3.7 150 129.5 0.7 ○ Example 250 10 9 3.9 140 129.30.5 ○ Example 250 20 124.11 30 68.5 0.9 ○ Example 250 25 124.4 150 129.6 1.0 ○ Comparative example 250 0 242.5 100 56.43.1 × Comparative example 250 40 33.1 200 57.3 2.2 ×

[0257] Referring to Table 7 above, the low-temperature stabilization treatment of the example was performed in the range of 10 to 25°C for 6 to 12 hours, and the high-temperature stabilization treatment was performed in the range of 130 to 150°C for 6 to 12 hours. At this time, when examining the weight loss after reheating the shredded material, it can be confirmed that it is 1.0% or less, and since the weight loss after reheating the shredded material satisfies 1.0% or less, it was confirmed that the electrolyte reduction amount was large and stability in the post-process was secured. In contrast, when the low-temperature stabilization treatment process was not performed or was performed at a high temperature such as 40°C, there was a problem that there was a risk of fire in the battery, and it was confirmed that the weight loss of the obtained battery shredded material was low. In addition, when the low-temperature stabilization treatment was not sufficiently performed and the high-temperature stabilization treatment was performed, there was a problem that low-temperature volatile electrolyte was excessively generated during the high-temperature treatment, which further increased the risk of fire, and there was a problem that the electrolyte reduction was not sufficiently achieved compared to the standard time.

[0258] <Evaluation Example>: Data according to the spacing between hot air inlets and seals in the Sagger

[0259] Table 8 below shows the time it takes to reach the target temperature when the spacing between the hot air inlets in the saga is different and when the spacing between the sealed part and the mesh part is different.

[0260] Figure 16 shows a graph of the heating rate according to the spacing of hot air inlets.

[0261] Referring to Fig. 16, when the spacing between the hot air inlets satisfies 35 to 45.0% of the horizontal length of the saga, it can be confirmed that the target temperature is quickly reached at a heating rate of 2.0°C / min or higher. Through this, it can be confirmed that the process efficiency is excellent when the spacing between the hot air inlets described above is maintained.

[0262] Figure 16 shows a graph of temperature versus time according to the spacing of the hot air inlet and the spacing of the sealing part.

[0263] Case (Case) Horizontal (long axis) length of case [mm] Spacing between hot air inlets [mm] Vertical (height) length of case [] Height of sealed part [mm] Time to reach 120℃ Seconds (sec) Minutes (min) Case 01710300500403,55259.2 Case 027103005001703,32655.43 Case 03710300500323.51,99733.17 Case 04710200500403,73662.27 Case 05710340500403,63460.57

[0264] Referring to Table 8 and Fig. 16, it can be seen that the reaching time is reduced by about 6% in Case 02 and about 44% in Case 03 compared to Case 01, so that the time taken to reach the target temperature range of the saga can be minimized by satisfying the height of the sealing part within the appropriate height range. In addition, looking at Case 04 and Case 05, it can be seen that the time taken to reach the target temperature range of the saga increases by about 5% and 2%, respectively, compared to Case 01. Accordingly, the spacing between the hot air inlets also satisfies the appropriate range, so that the time taken to reach the target temperature range of the saga can be minimized.

[0265] 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. Input section for inserting Sagger containing used battery shreds; A transport unit transporting the above-mentioned saga into which the above-mentioned waste battery shreds are put; A first stabilizing unit for stabilizing the waste battery shreds at a temperature of 30°C or less; A second stabilizing unit for stabilizing the waste battery fragments that have passed through the first stabilizing unit at a temperature of 30 to 150°C; and Including a discharge unit for discharging the stabilized waste battery fragments, The above-mentioned battery stabilization device includes a hot air inlet for supplying heat to the waste battery shredder.

2. In paragraph 1, The above first stabilizing unit is a battery stabilizing device including a compressor.

3. In paragraph 1, A battery stabilization device comprising at least one weight and temperature measuring unit for measuring the weight of the waste battery shreds.

4. In paragraph 3, The above weight and temperature measuring unit, A first weight and temperature measuring unit disposed between the above-mentioned inlet and the first stabilizing unit; A second weight and temperature measuring unit disposed between the first stabilizing unit and the second stabilizing unit; and A battery stabilization device including a third weight and temperature measuring unit disposed between the second stabilizing unit and the discharge unit.

5. In paragraph 4, The above second stable portion includes an intermediate stable portion and a high temperature stable portion, The above intermediate stabilizing unit heats the waste battery shreds to a temperature range of 30 to 120°C, The above high temperature stabilizing unit is a battery stabilizing device that heats the waste battery shreds to a range of 120 to 150°C.

6. In paragraph 1, The above hot air inlet is a battery stabilizing device positioned in at least a part of the above Sagger.

7. In paragraph 1, The above hot air inlet is arranged in the shape of a cylinder, a triangular column, a square column, or a polygonal column, A battery stabilizing device that dissipates heat through the outer surface of the above shape.

8. In paragraph 6, Containing a plurality of said hot air inlets, A battery stabilizing device wherein the spacing between the plurality of hot air inlets is 35 to 45% of the horizontal length of the saga.

9. In paragraph 1, A battery stabilizing device wherein the height of the hot air inlet is 25% to 50% of the height of the saga.

10. In paragraph 1, A battery stabilizing device wherein the height of the hot air inlet is 25% to 50% of the height of the saga.

11. In paragraph 1, The above-mentioned battery stabilizing device has a structure with an open upper surface.

12. In paragraph 1, The above saga comprises a housing surrounding the side of the above saga, A battery stabilizing device comprising a mesh portion and a sealing portion arranged below the mesh portion.

13. First step of controlling the tap density of waste battery shredder; A second step of measuring a first weight, which is an initial weight of the above-mentioned waste battery shreds, and a first temperature, which is an initial temperature; A third step of stabilizing the above-mentioned waste battery shreds at a temperature of 30°C or lower; A fourth step of measuring the second weight and second temperature of the waste battery shreds that have gone through the third step; A fifth step of stabilizing the waste battery shreds that have gone through the fourth step at a temperature of 30 to 150°C; A sixth step of measuring the third weight and third temperature of the waste battery shreds that have gone through the fifth step; and A battery stabilization treatment system including a seventh step of discharging the waste battery shreds that have passed through the sixth step.

14. In paragraph 13, The first step is to increase the tap density of the waste battery shreds to 200 to 1,400 kg / m. 3 A battery stabilization processing system controlled by .

15. In paragraph 13, A battery stabilization treatment system that performs step 5 when the first weight and the first temperature of the waste battery shreds measured in the second step and the second weight and the second temperature of the waste battery shreds measured in the fourth step satisfy the following equations 1 and 2. <Formula 1> 2nd weight - 1st weight ≤ 25% <Formula 2> Second temperature - First temperature ≤ 25 ℃ 16. In paragraph 13, A battery stabilization treatment system that performs step 7 when the second weight and the second temperature of the waste battery shreds measured in step 4 and the third weight and the third temperature of the waste battery shreds measured in step 6 satisfy the following equations 3 and 4. <Formula 3> 3rd weight - 2nd weight ≤ 10% <Formula 4> 3rd temperature - 2nd temperature ≤ 25 ℃ 17. In paragraph 13, The above fifth step is performed by multi-stage heat treatment, A battery stabilization treatment system in which the above multi-stage heat treatment is sequentially performed at temperatures of 30 to 120°C and 120 to 150°C.

18. In paragraph 13, Before the first step of controlling the tap density of the above-mentioned waste battery shredder, A battery stabilization processing system comprising a step of controlling the unit waste battery shredder constituting the above waste battery shredder to satisfy the following conditions 1 and 2. <Condition 1> The above layered structure is a laminated structure having 1 or more layers and 7 or fewer layers. <Condition 2> The size of the unit waste battery shreds based on the long axis, which is the longest axis among the horizontal, vertical, and height directions, is 100 mm or less.

19. In paragraph 13, Prior to the first step, a step of freezing the waste battery shreds is further included, A battery processing system in which the above freezing step is performed by cooling to -150°C to -20°C.

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