Method of disposing battery comprising method for discharging waste battery

Abstract

The present invention relates to a method of disposing a battery and, more specifically, to a method of disposing a battery comprising a method for discharging a waste battery containing lithium, the method of disposing a battery comprising the steps of: preparing a battery; and water-discharging the battery in an aqueous solution containing a sulfuric acid-based ionic material, wherein the sulfuric acid-based ionic material is a by-product generated in a waste battery recycling process.

Description

Battery disposal method including a method for discharging waste batteries

[0001] The present invention relates to a method for processing a battery, and more particularly, to a method for processing a battery, including a method for discharging a lithium-containing battery.

[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 mainly consists of copper and aluminum used as a current collector, oxides containing Li, Ni, Co, Mn, Fe, Al, and P 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 used as a solvent (Solvent0) and salt constituting the electrolyte are mainly mixed with carbonate organic substances such as ethylene carbonate and propylene carbonate, and for example, LiPF6 is used.

[0004] To utilize these waste batteries, active development is underway on a recycling process that safely discharges them before crushing them. Discharged batteries undergo drying and calcination processes to remove moisture and electrolytes within the batteries. Following the drying and calcination processes, the batteries undergo crushing, exfoliation, and particle size sorting to produce a black powder containing lithium, nickel, cobalt, manganese, iron, phosphorus, aluminum, copper, and graphite.

[0005] Here, various methods for discharging lithium-containing waste batteries include water discharge, which uses water as a medium, and electrical discharge, which discharges electrically. Water discharge involves forcibly discharging a lithium-ion battery by submerging the battery in water. In water discharge, forced short circuits can cause electrolyte leakage from the battery and float on the water surface. Excessive water discharge can cause the water temperature to rise, potentially igniting the electrolyte and potentially causing a fire on the water surface, even during water discharge. Water discharge also has the drawback of taking longer to discharge than electrical discharge. Because water discharge utilizes the ionic conductivity of water to force discharge, it can slow down the discharge rate compared to methods that apply an external voltage, such as electrical discharge. However, water discharge eliminates the rebound phenomenon, which restores voltage after discharge, allowing for safer post-processing, such as crushing and particle size sorting, to recover valuable metals within the battery.

[0006] In this case of water discharge, in order to improve the discharge speed, materials with high ionic conductivity can be dissolved to increase the discharge speed. NaCl is used as the material with high ionic conductivity, but the NaCl may remain in the battery and cause a problem of corrosion of the equipment by generating Na or Cl gas during the firing and drying process. In addition, the black powder obtained after the crushing and particle size selection process may remain in the black powder and generate two or more anions Cl in the aqueous solution during acid leaching using sulfuric acid or nitric acid. - , SO4 2- , or NO3 - There is a problem that the recovery rate of valuable metals is low because pH control is difficult to perform to remove impurities while remaining.

[0007] To address these issues, research is needed on alternatives to NaCl that can improve ionic conductivity in aqueous solutions during battery discharge, accelerate discharge rates, and simultaneously minimize solid residues remaining after drying and calcination processes.

[0008] The technical problem to be solved by the present invention is to provide a battery treatment method including a method of discharging a lithium-containing battery using a substitute for NaCl that can improve ionic conductivity in an aqueous solution during battery discharge, accelerate the discharge rate, and at the same time minimize solid residue remaining after the drying and firing processes.

[0009] A method for processing a battery, comprising a step of discharging a waste battery containing lithium, according to one embodiment of the present invention, comprises a step of preparing a battery, and a step of discharging the battery in an aqueous solution containing a sulfuric acid ionic substance, wherein the sulfuric acid ionic substance may be a byproduct generated in a waste battery recycling process.

[0010] In one embodiment, the sulfuric acid ion material may be Na2SO4. In one embodiment, the Na2SO4 may be a byproduct generated during the hydrometallurgical and precursor manufacturing processes.

[0011] In one embodiment, the step of discharging the battery in an aqueous solution containing a sulfuric acid ion material may be such that the concentration of the sulfuric acid ion material is 5 wt% or more to 20 wt% based on 100 wt% of the aqueous solution. In one embodiment, the step of discharging the battery in an aqueous solution containing a sulfuric acid ion material may be such that the temperature of the aqueous solution is 20° C. or more.

[0012] In one embodiment, after the step of discharging, a step of calcining the discharged result at a temperature of 200°C or higher may be included. In one embodiment, a step of acid leaching the black mass that has undergone the step of discharging may be included. In one embodiment, the acid leaching may utilize sulfuric acid.

[0013] In one embodiment, the step of preparing the battery may include forming an ion water inlet in at least one of a cylindrical, pouch-shaped, and prismatic battery. In one embodiment, the step of forming the ion water inlet may include cutting the battery.

[0014] In one embodiment, when the battery is pouch-shaped or square-shaped, the step of cutting the battery may satisfy the following equation 1.

[0015] <Formula 1>

[0016] 0.02 ≤ L = [incision length] / [total surface length] ≤ 0.9

[0017] (In the above formula 1, [cut length] and [total surface length] mean the long axis length of the cut portion when the battery is cut and the long axis reference length of the battery, respectively)

[0018] In one embodiment, when the battery is circular, the ion water inlet has a hole shape, and the cross-sectional area of ​​the hole is 0.01 mm. 2 It may be ideal. In one embodiment, the cross-sectional area of ​​the ion water inlet is 0.01 mm 2 It may be ideal. In one embodiment, the depth of the ion water injection port may be 0.05 mm or more. In one embodiment, the recovery rate of Ni recovered after the acid leaching step may be 90% or more.

[0019] According to one embodiment of the present invention, a battery treatment method includes a battery discharge method utilizing sodium nitrate (Na2SO4) as an additive for improving ionic conductivity in an aqueous solution during water discharge, thereby improving ionic conductivity in an aqueous solution during battery water discharge, accelerating the discharge speed, and at the same time minimizing solid residue remaining after a drying and firing process.

[0020] FIG. 1 is a drawing showing a step of forming a cut surface in a pouch or square battery according to one embodiment of the present invention.

[0021] FIG. 2 is a drawing showing a step of forming a hole in a cylindrical battery according to one embodiment of the present invention.

[0022] 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 only 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.

[0023] 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.

[0024] 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.

[0025] Additionally, % in this specification means weight % unless otherwise specified.

[0026] 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.

[0027] 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.

[0028] According to one embodiment of the present invention, a battery treatment method comprises a step of discharging a waste battery containing lithium. Specifically, the battery treatment method comprises a step of preparing a battery and a step of discharging the battery in an aqueous solution containing a sulfuric acid ion substance.

[0029] The step of preparing a battery may be a step of preparing a waste battery. The waste battery may be, for example, a lithium secondary battery separated from an automobile, a secondary battery separated from an electronic device such as a cell phone, a camera, or a laptop, and specifically, a lithium secondary battery.

[0030] In one embodiment, in the step of preparing a battery, the battery may include at least one of a cylindrical, pouch-shaped, and prismatic shape. Specifically, the battery may refer to at least one battery cell included in a battery pack or module.

[0031] The step of discharging the battery in an aqueous solution containing a sulfuric acid ion substance may be a step of discharging the battery by immersing the battery in an aqueous solution containing a sulfuric acid ion substance or by introducing the aqueous solution into the battery.

[0032] Specifically, the battery can generate a large amount of heat when the battery's own energy is short-circuited, as shown in the reaction equation below, as the current rapidly increases in a very low resistance situation. This large amount of heat heats the flammable electrolyte material, posing a risk of fire or explosion.

[0033] [Reaction formula]

[0034] H = Heat of Joule = I 2 / R*△t (I=current, R=resistance, △t=short-circuit exposure time)

[0035] In addition, as in the conventional method, discharging the battery with a saline solution using an ionic substance such as NaCl can suppress the exothermic reaction due to the short-circuit phenomenon that occurs during forced discharge, but there is a problem in that HF ​​gas, a harmful gas generated when fluorine dissolved in the electrolyte during discharge is converted to gas, and wastewater is generated in which F is dissolved.

[0036] In one embodiment of the present invention, by including a step of discharging a battery in an aqueous solution containing a sulfuric acid ionic substance, the ionic substance is treated with sulfuric acid in the leaching step to form SO4 2- It can suppress the formation of harmful gases by reducing the interference effect with ions, and at the same time minimize the solid residue remaining after the drying and firing process.

[0037] In one embodiment, the sulfuric acid ion material may be sodium sulfate (Na2SO4). The sodium sulfate may be a byproduct generated in a waste battery recycling process. Specifically, the sodium sulfate is a representative byproduct generated in a waste battery recycling process, specifically, a hydrometallurgical and precursor manufacturing process. The sodium sulfate is partially contaminated with nickel, cobalt, manganese, lithium, etc. during the hydrometallurgical and precursor manufacturing processes, and thus has a characteristic of having more impurities than the sodium sulfate previously used. These substances may be less than 1% in the sodium sulfate.

[0038] The above-mentioned nitrous oxide is generated in an amount approximately 2 to 3 times greater than the amount of material input during solvent extraction in wet refining, and thus, when buried in landfill, it contaminates the soil with environmentally hazardous substances. By recycling the nitrous oxide with the sulfuric acid ion material in the battery processing method of the present invention, an environmentally friendly, economical, and minimally invasive battery processing method is provided.

[0039] In one embodiment, the step of discharging the battery in an aqueous solution containing a sulfuric acid ionic substance may be such that the concentration of the sulfuric acid ionic substance is 5 wt% to 40 wt% based on 100 wt% of the aqueous solution. Specifically, the concentration of the sulfuric acid ionic substance may be 8.5 to 30 wt%, more specifically, 10 to 25 wt%, more specifically, 9 to 20 wt%, and even more specifically, 10 to 15 wt%.

[0040] By ensuring that the concentration of the sulfuric acid ion substance satisfies the aforementioned range, the battery can be safely discharged while maintaining an appropriate discharge rate. If the concentration exceeds the upper limit of the aforementioned range, the risk of fire increases due to an excessive discharge rate, which can lead to an increase in the temperature of the ionized water. If the concentration exceeds the lower limit of the aforementioned range, the discharge rate can be delayed.

[0041] In one embodiment, the step of discharging the battery in an aqueous solution containing a sulfuric acid ion material may be performed at a temperature of 20° C. or higher. Specifically, the temperature may be 20 to 80° C., more specifically, the temperature may be 40 to 80° C., and even more specifically, 60 to 80° C.

[0042] By ensuring that the temperature satisfies the aforementioned range, the discharge rate can be improved under the same concentration. If the temperature exceeds the upper limit of the aforementioned range, there is a risk of fire due to excessive discharge, temperature rise, and evaporation of ions. If the temperature exceeds the lower limit of the aforementioned range, the movement of ions slows, delaying the discharge time.

[0043] In one embodiment, after the step of discharging the water, a step of calcining the discharged water result at a temperature of 200° C. or higher may be included. Specifically, the step of calcining the discharged water result at the aforementioned temperature range may be 200 to 500° C., specifically, 200 to 400° C., and more specifically, 250 to 350° C. The calcining step may be a step of volatilizing and removing substances such as ionized water or electrolyte remaining inside the battery after the discharge of the battery using ionized water is completed.

[0044] When the temperature of the above-mentioned firing step satisfies the above-mentioned temperature range, the liquid substance remaining inside the battery is completely volatilized, which has the advantage of improving safety during the battery processing process. If the temperature of the above-mentioned firing step exceeds the upper limit of the above-mentioned range, there is a problem in that harmful gases such as H2 or SO2 are generated. If the temperature of the above-mentioned firing step exceeds the lower limit of the above-mentioned range, there is a problem in that the liquid substance inside the battery is not easily removed.

[0045] In one embodiment, the step of crushing the battery may be included prior to the firing step. The step of crushing the battery may involve applying an external force to the discharged battery to crush it. Specifically, the step of crushing the battery may involve applying an impact or pressure to the battery to cause a portion of the battery to detach from the battery.

[0046] In one embodiment, the step of shredding the battery may include any of the following: crushing the battery, cutting the battery, compressing the battery, or a combination thereof. Specifically, the step of shredding may include any process that destroys the battery to produce small-sized shredded materials.

[0047] In one embodiment, the step of crushing the battery may include any process of destroying the battery by compressing the 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.

[0048] 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.

[0049] In one embodiment, the step of crushing the battery may be performed under conditions in which an inert gas, carbon dioxide, nitrogen, water, or a combination thereof is supplied, or under a vacuum atmosphere of 100 torr or less. By performing the crushing under such an atmosphere, explosion of the battery can be prevented, and the vaporization of the electrolyte can be suppressed, thereby preventing the generation of flammable gases such as ethylene, propylene, or hydrogen. By including the step of crushing the battery, process efficiency in subsequent drying or firing steps can be increased.

[0050] In one embodiment, the step of acid leaching the black mass that has undergone the calcination step may be included. Specifically, the acid leaching step may be a step using sulfuric acid. Specifically, the step may be a step of leaching the black mass with sulfuric acid to recover valuable metals.

[0051] In one embodiment, the acid leaching step may further comprise a reducing agent. Specifically, the acid leaching step may further comprise adding a reducing agent to the acidic solution to recover valuable metals from the black mass. In one embodiment, the reducing agent may be selected from the group consisting of hydrogen peroxide, H2S, SO2, FeSO4, coal, and pyrite. By further adding a reducing agent to the acidic solution, the acid leaching rate can be further increased.

[0052] In one embodiment, the recovery rate of Ni recovered after the acid leaching step may be 90% or more. Thus, by adding the nitrous oxide of the present invention as an ionic substance during the water discharge, interference with sulfuric acid in the acid leaching step can be minimized, thereby increasing the recovery rate of Ni, a valuable metal.

[0053] FIG. 1 is a drawing showing a step of forming a cut surface in a pouch or square battery according to one embodiment of the present invention.

[0054] Referring to FIG. 1, a step of cutting a pouch-shaped or square-shaped battery is illustrated. In one embodiment, the pouch-shaped or square-shaped battery (1) may include a step of forming at least one ion water inlet (2) on the surface. The ion water inlet (2) may be a member into which an aqueous solution containing an ionic substance is injected to discharge the battery. Specifically, the ion water inlet (2) may be a region into which an aqueous solution containing an ionic substance is injected so that ion water can be easily injected during a discharge process of the battery. The square-shaped or pouch-shaped battery (1) has a problem in that the electrolyte vaporizes during a firing process, causing the battery to explode.

[0055] The step of forming the above ion injection port (2) may include a step of cutting the battery, thereby forming a region into which an aqueous solution containing an ionic substance is injected. Specifically, the region into which the aqueous solution containing the ionic substance is injected may refer to a cut surface. More specifically, the cut surface may refer to a region having a three-dimensional space extending in the thickness direction of the cylindrical battery from a two-dimensional shape included in the surface of the pouch-shaped or square-shaped battery.

[0056] In one embodiment, when the battery is pouch-shaped or square-shaped, the step of cutting the battery may satisfy the following equation 1.

[0057] <Formula 1>

[0058] 0.02 ≤ L = [incision length] / [total surface length] ≤ 0.9

[0059] (In the above formula 1, [cut length] and [total surface length] mean the long axis length of the cut portion when the battery is cut and the long axis reference length of the battery, respectively)

[0060] The above equation 1 may be an indicator of stabilization in the preprocessing stage of a pouch-shaped or square-shaped battery (1). Specifically, the equation 1 may satisfy a value of 0.02 to 0.9. By satisfying the above-described range, the discharge time can be appropriately maintained during the battery processing process, and the recovery rate of black mass can be increased.

[0061] If the above equation 1 exceeds the lower limit of the aforementioned range, there is a problem that the discharge time becomes longer because the electrolyte ion conductivity is not transmitted during discharge. If the above equation 1 exceeds the upper limit of the aforementioned range, the discharge time becomes shorter, but there is a problem that the battery expands excessively, damaging the battery surface and causing internal positive or negative electrode materials to be discharged to the outside, thereby reducing the recovery rate of black mass.

[0062] In one embodiment, the cross-sectional area of ​​the ion water injection port, which is the cut surface, is 0.01 mm 2 It may be ideal. Specifically, the cross-sectional area is 0.1 to 10.0 mm 2 , more specifically, 1.0 to 6.0 mm 2 can satisfy.

[0063] In one embodiment, a pouch-shaped or square-shaped battery (1) may include an outer shell comprising aluminum or iron; and a cathode material and an anode material disposed within the outer shell. In one embodiment, the outer shell of the pouch-shaped or square-shaped battery (1) may have a thickness of 0.01 to 1.0 mm. In one embodiment, the outer shell of the pouch-shaped or square-shaped battery (1) may have a total amount of Fe and Al of 70 at% or more, based on 100 at% of the battery outer shell.

[0064] FIG. 2 is a drawing showing a step of forming a hole in a cylindrical battery according to one embodiment of the present invention.

[0065] Referring to FIG. 2, a step of cutting a cylindrical battery (1) is illustrated. In one embodiment, the cylindrical battery (1) may include a step of forming at least one ion water inlet (2) on a surface. The ion water inlet (2) may be a member into which an aqueous solution containing an ionic substance is injected to discharge the battery. The cylindrical battery (1) has a problem in that the electrolyte vaporizes during the firing process, causing the battery to explode.

[0066] In one embodiment, the cross-sectional area of ​​the ion water injection port (2) is 0.01 mm 2 It may be ideal. Specifically, the cross-sectional area is 0.1 to 10.0 mm 2 , more specifically, 1.0 to 6.0 mm 2can be satisfied. When the cross-sectional area of ​​the ion injection port (2) satisfies the above-mentioned range, the hole is easily formed, and in the post-process, ion water is quickly injected into the battery, which has the advantage of shortening the discharge time. The horizontal cross-section of the hole may mean a three-dimensional space extending in the thickness direction of the cylindrical battery (1) from a two-dimensional shape included in the surface of the cylindrical battery. The hole may have a shape of, for example, a circle or a polygon, and the hole may include terms such as, for example, a hole, a gap, or a crack.

[0067] In one embodiment, the depth of the hole may be 0.05 mm or greater. The depth of the hole may refer to the vertical distance between an arbitrary line drawn in a direction parallel to the horizontal direction of the cylindrical battery and the surface of the cylindrical battery. Specifically, the depth of the hole may be 0.1 to 1.5 mm, and more specifically, 0.5 to 1.0 mm.

[0068] Referring to FIGS. 1 and 2, in one embodiment, the number of ion water injection ports (2) may be 1 to 40. Specifically, the number of ion water injection ports (2) may be 2 to 30, and more specifically, 2 to 15. Since the number of ion water injection ports (2) satisfies the above-described range, it is easy to inject ion water during water discharge, and the process time can be shortened to safely discharge the battery.

[0069] In one embodiment, the step of forming the ion injection port may form a passage through which ions are injected by various means, such as a drill, a punch, a needle, a laser, a cutter, a compression fracture, or a shear fracture means.

[0070] In one embodiment, a cylindrical battery may include an iron-containing outer shell and a cathode and an anode material disposed within the outer shell. The iron-containing outer shell may include at least 60 at% iron based on 100 at% of the outer shell.

[0071]

[0072] <Experimental Example>

[0073] Comparison of discharge speed according to the concentration of ionic substances injected during water discharge

[0074] The discharge rate was compared according to the type of ionic substance introduced into the aqueous solution during the battery discharge method. The ionic substances introduced were NaCl, Na2SO4, and NaNO3. One side of the pouch-type battery was cut, and the cut length was adjusted to 50% of the total length, and the L value was adjusted to 0.5.

[0075] Additionally, the temperature of the ion water was maintained at approximately 20°C, and the discharge time and residual voltage within the battery were measured.

[0076] Table 1 below shows the battery discharge time and residual voltage according to the type and concentration of ionic substances. The concentration of ionic substances refers to the concentration based on 100 wt% aqueous solution, and the discharge time and residual voltage were measured using the following method.

[0077] Discharge time: Measured by recording method using a digital timer device.

[0078] Residual voltage: The voltage change according to the discharge time was measured using a voltage recorder device.

[0079]

[0080] Ionic substance concentration (wt%)Discharge time (hours)Residual voltage (V)RemarksNaCl5220.1Comparative example10120.1Comparative example1560.2Comparative example2040.2Comparative exampleNa2SO45310.2Example10180.3Example15130.1Example2090.1ExampleNaNO35380.1Comparative example10260.2Comparative example15180.1Comparative example20120.2Comparative example

[0081] Looking at Table 2 above, it was confirmed that the discharge time decreases as the concentration of the same ionic substance in the aqueous solution increases. In addition, it was confirmed that the discharge efficiency increases in the order of NaCl, Na2SO4, and NaNO3.

[0082] Discharge rate according to ion water temperature

[0083] The discharge speed of the battery was compared according to the type of ionic substance introduced into the aqueous solution during discharge. The ionic substances introduced during discharge were NaCl, Na2SO4, and NaNO3. One side of the pouch-type battery was cut, and the cut length was 50% of the total length, and the L value was 0.5. The ionic substance concentration was maintained at 10 wt%, and the ion water temperature was varied as shown in Table 2 below, and the discharge time and residual voltage of the battery were measured.

[0084] Ionic substance Temperature (℃) Discharge time (hours) Residual voltage (V) Note NaCl 20 1 20.1 Comparative example 40 100.1 Comparative example 60 80.2 Comparative example 80 70.2 Comparative example Na2SO4 20 180.2 Example 40 150.3 Example 60 110.1 Example 80 90.1 Example NaNO3 20 260.1 Comparative example 40 250.2 Comparative example 60 210.1 Comparative example 80 170.2 Comparative example

[0085] Referring to Table 3 above, it was confirmed that the discharge time decreased when the temperature of the ion water containing each ion substance was increased.

[0086] Effect of Ni recovery rate in wet smelting process after water discharge process by ionic substance

[0087] After the discharge process for each ionic substance, the black mass containing the positive / negative electrode materials was recovered through a calcination process. After the discharge process for each ionic substance, Cl that may remain in the black mass was recovered. - , SO4 2- , and NO3 -In order to confirm the influence of the acid-based wet refining process on the contained ionic substances, the Ni recovery rate was compared according to the type of acid and ionic substances used in the wet refining process.

[0088] The ionic substances introduced during battery discharge were NaCl, Na2SO4, and NaNO3. One side of the pouch-type battery was cut, and the cut length per total length was 50%, and the L value was 0.5. The ionic substance concentration was maintained at 10 wt%, the ion water temperature was maintained at 20°C, and the sintering treatment temperature was maintained at 300°C.

[0089] Table 3 below shows the nickel recovery rate when calcined and acid leached according to the type of ionic substances.

[0090] Discharge ion substance ion substance concentration (wt%) ion water temperature (℃) calcination treatment temperature (℃) leaching solution Ni recovery rate (%) NaCl 10 20 30 0 H 2 SO 4 8 1 Na 2 SO 4 H 2 SO 4 9 8 Na NO 3 H 2 SO 4 8 6 Na 2 SO 4 5 0 H 2 SO 4 7 3 Na 2 SO 4 6 5 0 H 2 SO 4 8 4

[0091] Referring to Table 3 above, Cl, the anion of ionic substances - , SO4 2- , NO3 - It was confirmed that the highest recovery rate could be obtained when leaching using acids (HCl, H2SO4, HNO3) containing anions matching with Ni was performed and Ni was recovered. This is because Cl remained inside the black mass and was present in the aqueous solution when acid leaching was performed using sulfuric acid or nitric acid. - , SO4 2- , NO3 - It was confirmed that there is a problem that the pH control performed to remove impurities becomes difficult when two or more types of anions remain, thereby reducing the recovery rate of valuable metals.

[0092] Results of water discharge using recycled Na2SO4 and 10H2O

[0093] Large quantities of nitrous oxide, generated during wet refining and precursor manufacturing processes, are a key byproduct of the LiB battery recycling process. This nitrous oxide is an environmentally hazardous substance that can contaminate soil when landfilled.

[0094] The amount of the above-mentioned nitrate generated is about 2 to 3 times that of the material input in the solvent extraction process of wet refining, so the amount of the above-mentioned nitrate generated is about 2 to 3 times that of the material input in the solvent extraction process of wet refining. The present invention relates to the recycling of the above-mentioned nitrate, and was performed by inputting the above-mentioned nitrate as an ionic material during the water discharge of a waste battery. At this time, the battery was a pouch-type battery, and one side was cut, and the cut length by total length was 50%, the L value was 0.5, and the temperature of the ion water was maintained at 20 ℃, and the discharge time and the residual voltage in the battery were measured. Afterwards, it was subjected to a calcination treatment at 300 ℃, and an acid leaching process was performed to evaluate the recovery rate of Ni.

[0095] Table 4 below shows the nickel recovery rate from the battery according to the discharge conditions.

[0096] Discharge time (hours) Residual voltage (V) Calcination temperature (℃) Leachate Ni recovery rate (%) (Na2SO4)·10H2O170.1300H2SO499NaCl120.1H2SO481NaNO3260.2H2SO486

[0097] Looking at Table 4 above, when treated with sulfuric acid, the amount of SO4 2- It was confirmed that the recovery rate of valuable metals such as Li, Ni, and Co was superior to that of ionic substances such as NaCl and NaNO3 due to the absence of interference effects with ions. In this way, the example using MgSO showed superior recovery rate of Ni compared to other ionic substances during sulfuric acid treatment.

[0098] 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. A method for processing a battery, comprising a step of discharging a waste battery containing lithium, Steps to prepare the battery; and Comprising a step of discharging the battery in an aqueous solution containing a sulfuric acid ion substance, The above sulfuric acid ion substance is a battery processing method that is a by-product generated in the waste battery recycling process.

2. In paragraph 1, A battery treatment method in which the above sulfuric acid ion substance is sodium hypochlorite (Na2SO4).

3. In paragraph 2, The above-mentioned battery processing method is a by-product generated in the wet refining and precursor manufacturing processes.

4. In paragraph 1, A battery treatment method wherein the step of discharging the battery in an aqueous solution containing a sulfuric acid ion substance has a concentration of the sulfuric acid ion substance of 5 wt% or more to 40 wt% based on 100 wt% of the aqueous solution.

5. In paragraph 1, A battery treatment method wherein the step of discharging the battery in an aqueous solution containing a sulfuric acid ion substance has a temperature of 20° C. or higher.

6. In paragraph 1, After the above water discharge step, A battery processing method comprising a step of calcining the above-mentioned discharged result at a temperature of 200° C. or higher.

7. In paragraph 6, A battery processing method comprising a step of acid leaching black mass that has undergone the above-mentioned calcination step.

8. In paragraph 7, The above acid leaching is a battery treatment method using sulfuric acid.

9. In paragraph 1, A battery processing method, wherein the step of preparing the battery comprises a step of forming an ion water inlet in at least one of a cylindrical, pouch-shaped, and square-shaped battery.

10. In clause 10, A battery processing method, wherein the step of forming the ion water injection port includes the step of cutting the battery.

11. In Article 10, If the above battery is pouch-shaped or square-shaped, The step of cutting the above battery is a battery processing method satisfying the following equation 1. <Formula 1> 0.02 ≤ L = [cut length] / [total surface length] ≤ 0.9 (In the above formula 1, [cut length] and [total surface length] mean the long axis length of the cut portion when the battery is cut and the long axis standard length of the battery, respectively.) 12. In paragraph 10, If the above battery is circular, The above ion water injection port has a hole shape, The cross-sectional area of ​​the above hole is 0.01 mm 2 How to dispose of an abnormal battery.

13. In paragraph 11, The cross-sectional area of ​​the above ion water inlet is 0.01 mm 2 How to dispose of an abnormal battery.

14. In paragraph 12, A battery processing method wherein the depth of the above ion water injection port is 0.05 mm or more.

15. In paragraph 9, A battery processing method wherein the recovery rate of Ni recovered after the above acid leaching step is 90% or more.

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