Battery disposal method including a method for discharging used batteries

Abstract

The present invention relates to a battery processing method, and more specifically to a battery processing method including a method for discharging a lithium-containing waste battery, comprising the steps of preparing the battery and discharging the battery with an aqueous solution containing a sulfate-based ionic substance, wherein the sulfate-based ionic substance is a by-product generated in the waste battery recycling process.

Description

[Technical Field]

[0001] More specifically, the present invention relates to a battery processing method, including a method for discharging lithium-containing batteries. [Background technology]

[0002] As demand for electric vehicles increases globally, the problem of disposing of waste batteries generated from these vehicles is emerging as a social issue. In the case of lithium secondary batteries, which are the main raw materials for these waste batteries, organic solvents, explosives, and heavy metals such as Ni, Co, Mn, and Fe are included. However, Ni, Co, Mn, and Li have significant rarity value as valuable metals, and the recovery and reuse process of lithium secondary batteries after they are discarded is emerging as an important research area.

[0003] Specifically, a lithium secondary battery mainly consists of copper and aluminum used as a current collector, Li, Ni, Co, Mn, Fe, Al, and P-containing oxides that constitute the positive electrode material, and graphite used as the negative electrode material. It also includes a separator plate that separates the positive and negative electrode materials and an electrolyte injected into the separator plate. The solvent and salt used to constitute the electrolyte are mainly carbonate organic materials such as ethylene carbonate and propylene carbonate, for example, LiPF6 is used.

[0004] In order to utilize the aforementioned waste batteries, active development is underway on a reuse process that safely discharges the waste batteries before they are crushed. The discharged waste batteries undergo drying and firing processes to remove moisture and electrolytes from inside the batteries. After the drying and firing processes, black powder containing Li, Ni, Co, Mn, Fe, P, AlCu, and graphite is produced through crushing, delamination, and particle size sorting.

[0005] At this time, there are various methods for discharging lithium-containing waste batteries, including water discharge, which uses water as a medium, and electrical discharge, which discharges electrically. In the case of water discharge, the battery itself is immersed in water, which acts as a medium, and the lithium-ion battery is forcibly discharged. In the case of water discharge, the electrolyte leaks out of the battery due to forced disconnection and floats on the water surface. If the water temperature rises due to excessive water discharge, the electrolyte can ignite, and there is a risk of fire occurring on the water surface even during water discharge. Another problem with water discharge is that the discharge time is longer compared to electrical discharge. In the case of water discharge, because forced discharge is performed by utilizing the conductivity of water ions, there is a problem that the discharge rate is lower compared to electrical discharge, which is discharged by applying an external voltage. However, in the case of water discharge, the rebound phenomenon in which the voltage is restored after discharge is not observed, so subsequent processes such as crushing and particle size sorting to recover valuable metals inside the battery can be carried out safely.

[0006] In the case of water discharge, the discharge rate can be increased by dissolving a substance with high ionic conductivity to improve the discharge rate. NaCl is used as the substance with high ionic conductivity, but the NaCl can remain in the battery and generate Na or Cl gas during the firing and drying process, causing corrosion of the equipment. In addition, it remains inside the black powder obtained after the crushing and particle size sorting process, and during acid leaching using sulfuric acid or nitric acid, two or more negative ions Cl are added to the aqueous solution. - SO4 2- , or NO3 - The presence of residual substances makes pH adjustment, which is necessary to remove impurities, difficult, leading to a problem of reduced valuable metal recovery rates.

[0007] To solve these problems, research is needed on alternatives to NaCl that can improve the conductivity of ions in aqueous solutions during battery water discharge, thereby accelerating the discharge rate, while simultaneously minimizing solid residues remaining after the drying and calcination processes. [Overview of the project] [Problems that the invention aims to solve]

[0008] The technical problem that the present invention aims to solve is to provide a battery processing method that includes a method for discharging a lithium-containing battery, which utilizes a NaCl substitute that can improve the ionic conductivity in the aqueous solution during battery water discharge, accelerate the discharge rate, and minimize solid residues remaining after the drying and calcination processes. [Means for solving the problem]

[0009] The present invention relates to a battery processing method that includes the step of discharging a lithium-containing waste battery, comprising the steps of preparing the battery and discharging the battery with an aqueous solution containing a sulfate-based ionic substance, wherein the sulfate-based ionic substance may be a by-product generated in the waste battery recycling process.

[0010] In one embodiment, the sulfate-based ionic substance may be sodium sulfate (Na2SO4). In one embodiment, the sodium sulfate may be a byproduct generated in the wet smelting and precursor manufacturing process.

[0011] In one embodiment, the step of discharging the battery with an aqueous solution containing a sulfate-based ionic substance may be performed with a concentration of the sulfate-based ionic substance of 5% to 20% by weight based on 100% by weight of the aqueous solution. In one embodiment, the step of discharging the battery with an aqueous solution containing a sulfate-based ionic substance may be performed with a temperature of 20°C or higher of the aqueous solution.

[0012] In one embodiment, the process may include a step of firing the resulting product at a temperature of 200°C or higher after the water discharge step. In one embodiment, the process may include a step of acid leaching the black mass that has undergone the firing step. In one embodiment, sulfuric acid may be used for the acid leaching.

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

[0014] In one embodiment, when the battery is a pouch-type or square battery, the step of cutting open the battery may satisfy the following Equation 1. <Equation 1> 0.02 ≦ L = [Cutting length] / [Total surface length] ≦ 0.9 (In Equation 1, [Cutting length] and [Total surface length] respectively mean the length of the major axis of the cut portion when the battery is cut open and the length of the major axis of the battery.)

[0015] [[ID=1十三]] In one embodiment, when the battery is circular, the ionized water inlet has a hole shape, and the cross-sectional area of the hole may be 0.01 mm 2 or more. In one embodiment, the cross-sectional area of the ionized water inlet may be 0.01 mm 2 or more. In one embodiment, the depth of the ionized water inlet 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. https: / / www.wipo.int / pctdb / en / wo.jsp?WO=2016110473

Advantages of the Invention

[0016] The battery treatment method according to an embodiment of the present invention is an additive substance for improving the conductivity of ions in an aqueous solution during water discharge, and by including a battery discharge method utilizing sodium sulfate (Na2SO4), it can improve the conductivity of ions in the aqueous solution during battery water discharge, accelerate the discharge rate, and at the same time minimize the solid residue remaining after the drying and firing processes.

Brief Description of the Drawings

[0017] [Figure 1] The drawing shows a step of forming a cut surface on a pouch or square battery according to an embodiment of the present invention.

[0018] [Figure 2] A drawing showing the step of forming a hole in a cylindrical battery according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Terms such as first, second, and third are used to describe various parts, components, regions, layers, and / or sections, but are not limited thereto. These terms are only used to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Thus, the first part, component, region, layer, or section described below may be referred to as the second part, component, region, layer, or section without departing from the scope of the present invention.

[0020] The technical terms used herein are merely for referring to specific embodiments and are not intended to limit the present invention. The singular forms used herein include the plural forms as well, unless the context clearly indicates the contrary meaning. As used in the specification, "comprising" means to embody specific characteristics, regions, elements, steps, operations, elements, and / or components, and does not exclude the presence or addition of other characteristics, regions, elements, steps, operations, elements, and / or components.

[0021] When a part is described as "on" or "above" another part, it may be directly above or above the other part, or there may be other parts intervening therebetween. In contrast, when a part is described as "directly above" another part, there are no other parts intervening therebetween.

[0022] Also, % in this specification means weight % unless otherwise specified.

[0023] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as those generally understood by those skilled in the art in which this invention pertains. Terms defined in commonly used dictionaries are to be interpreted as having the meaning consistent with the relevant technical documents and the present disclosures, and are not to be interpreted as ideal or highly formal unless otherwise defined.

[0024] The following describes embodiments of the present invention in detail. However, these are presented as examples only and do not limit the present invention, which is defined solely by the claims described below.

[0025] One embodiment of the present invention relates to a battery processing method that includes the step of discharging a waste battery containing lithium. Specifically, the battery processing method of the present invention includes the step of preparing a battery and the step of discharging the battery with an aqueous solution containing a sulfate-based ionic substance.

[0026] The step of preparing a battery may be the step of preparing a waste battery. The waste battery may be, for example, a lithium secondary battery separated from an automobile, or a secondary battery separated from an electronic device such as a mobile phone, camera, or laptop computer, specifically a lithium secondary battery.

[0027] In one embodiment, the battery preparation step may include at least one battery that is cylindrical, pouch-type, and rectangular. Specifically, the battery may also mean at least one battery cell contained in a battery pack or module.

[0028] The step of discharging the battery with an aqueous solution containing sulfate-based ions may be a step of immersing the battery in an aqueous solution containing sulfate-based ions, or of introducing the aqueous solution into the battery and discharging the battery.

[0029] Specifically, if the battery's inherent energy is interrupted, the current can rapidly increase in a situation with extremely low resistance, as shown in the reaction equation below, generating a large amount of heat. This large amount of heat heats the flammable electrolyte material, posing a risk of fire or explosion. [Reaction Equation] H = Heat of Joule = I 2 / R*△t(I=current, R=resistance, △t=exposure time of open circuit)

[0030] Furthermore, while discharging the battery with saltwater using ionic substances such as NaCl, as in conventional methods, can suppress the heat reaction due to the disconnection phenomenon that occurs during forced discharge, it has the problem of generating wastewater containing HF gas and F, which are harmful gases produced when fluorine dissolved in the electrolyte turns into gas (Gas) during discharge.

[0031] In one embodiment of the present invention, the battery is subjected to a water discharge in an aqueous solution containing a sulfate-based ionic substance, thereby the ionic substance undergoes sulfuric acid treatment during the leaching step, resulting in SO4 2- This reduces interference effects with ions, suppresses the formation of harmful gases, and minimizes residual solids that remain after the drying and calcination processes.

[0032] In one embodiment, the sulfate-based ionic substance may be sodium sulfate (Na2SO4). The sodium sulfate may be a by-product generated in the waste battery recycling process. Specifically, the sodium sulfate is a typical by-product generated in the waste battery recycling process, specifically in the wet smelting and precursor manufacturing processes. The sodium sulfate is partially contaminated with Ni, Co, Mn, Li, etc. during the wet smelting and precursor manufacturing processes, and is characterized by having more impurities than conventionally used sodium sulfate. This substance may make up 1% or less of the sodium sulfate.

[0033] The aforementioned sodium sulfate is generated at a rate of approximately 2 to 3 times that of the substances introduced during solvent extraction in wet smelting, and when it is landfilled, it poses a problem of soil contamination with environmentally harmful substances. In the battery processing method of the present invention, by reusing the aforementioned sodium sulfate as the sulfate-based ionic substance, it is possible to provide a battery processing method that is environmentally friendly, economical, and minimizes side reactions with sulfuric acid in subsequent processes.

[0034] In one embodiment, the step of discharging the battery with an aqueous solution containing a sulfate-based ionic substance may be performed such that the concentration of the sulfate-based ionic substance is 5% by weight or more to 40% by weight based on 100% by weight of the aqueous solution. Specifically, the concentration of the sulfate-based ionic substance may be 8.5 to 30% by weight, more specifically 10 to 25% by weight, more specifically 9 to 20% by weight, and more specifically 10 to 15% by weight.

[0035] When the concentration of the sulfate-based ionic substance satisfies the aforementioned range, the battery can be safely discharged while maintaining an appropriate discharge rate. If the concentration falls outside the upper limit of the aforementioned range, there is a problem that the ion water temperature will rise due to the excessive discharge rate, increasing the risk of fire. If the concentration falls outside the lower limit of the aforementioned range, there is a problem that the discharge rate will be delayed.

[0036] In one embodiment, the step of discharging the battery with an aqueous solution containing a sulfate-based ionic substance may be performed when the temperature of the aqueous solution is 20°C or higher. Specifically, the temperature may be 20 to 80°C, more specifically, 40 to 80°C, and more specifically, 60 to 80°C.

[0037] By keeping the temperature within the aforementioned range, the discharge rate can be improved at the same concentration. If the temperature falls outside the upper limit of the aforementioned range, there is a problem of increased risk of fire due to excessive discharge causing a temperature rise and evaporation of ionized water. If the temperature falls outside the lower limit of the aforementioned range, there is a problem of delayed discharge time due to slower movement of ionized substances.

[0038] In one embodiment, the step of firing the water discharged product at a temperature of 200°C or higher may be included after the water discharge step. Specifically, the step of firing the water discharged product at the aforementioned temperature range may be 200 to 500°C, more specifically 200 to 400°C, and more specifically 250 to 350°C. The firing step may be a step of volatilizing and removing ionized water or electrolytes and other substances remaining inside the battery after the water discharge of the battery using ionized water is completed.

[0039] If the temperature of the firing step satisfies the aforementioned temperature range, any liquid substances remaining inside the battery are completely vaporized, which has the advantage of improving safety during the battery processing process. If the temperature of the firing step falls outside the upper limit of the aforementioned range, there is a problem that harmful gases such as H2 or SO2 will be generated. If the temperature of the firing step falls outside the lower limit of the aforementioned range, there is a problem that the liquid substances inside the battery cannot be easily removed.

[0040] In one embodiment, the step of crushing the battery may be included before the firing step. The step of crushing the battery may be a step of crushing the battery after it has undergone a discharge process by applying an external force. Specifically, the step of crushing the battery means a step of applying impact or pressure to the battery so that a part of the battery peels off from the battery.

[0041] In one embodiment, the step of crushing the battery means all of the steps of pulverizing the battery, cutting the battery, compressing the battery, and combinations thereof. Specifically, the crushing step may include all steps that destroy the battery to obtain small pieces of crushed material.

[0042] In one embodiment, the step of crushing the battery may include all steps of destroying the battery by compressing it or by applying an external force such as shear force or tensile force. The step of crushing the battery may be carried out, for example, using a crusher.

[0043] In one embodiment, the step of crushing the battery can be performed at least once. Specifically, the crushing step can be performed at least once, either continuously or discontinuously.

[0044] In one embodiment, the step of crushing the battery can be carried out under conditions of supplying an inert gas, carbon dioxide, nitrogen, water, or a combination thereof, or under a vacuum atmosphere of 100 torr or less. By crushing in the said atmosphere, the explosion of the battery can be prevented and the vaporization of the electrolyte can be suppressed, thus preventing the generation of flammable gases such as ethylene, propylene, or hydrogen. Including the battery crushing step can increase the process efficiency of subsequent drying or calcination steps.

[0045] In one embodiment, the process may include a step of acid leaching the black mass that has undergone the calcination step. Specifically, the acid leaching step may be a step using sulfuric acid. More specifically, it may be a step of leaching the black mass in sulfuric acid to recover valuable metals.

[0046] In one embodiment, the acid leaching step may further include a reducing agent. Specifically, the acid leaching step may be a step of further 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 increased.

[0047] In one embodiment, the recovery rate of Ni recovered after the acid leaching step can be 90% or more. Thus, by adding Glauber's salt of the present invention as an ionic substance during water discharge, interference with sulfuric acid in the acid leaching step can be minimized, and the recovery rate of Ni, a valuable metal, can be increased.

[0048] Figure 1 is a diagram illustrating the step of forming an incision surface in a pouch or rectangular battery according to one embodiment of the present invention.

[0049] Referring to Figure 1, the step of cutting open a pouch-type or rectangular battery is shown. In one embodiment, the pouch-type or rectangular battery 1 may include the step of forming at least one ionized water inlet 2 on its surface. The ionized water inlet 2 may be a component into which an aqueous solution containing an ionic substance is injected to discharge the battery. Specifically, the ionized water inlet 2 may be a region into which an aqueous solution containing the ionic substance is injected so that ionized water is easily injected during the water discharge process of the battery. The rectangular or pouch-type battery 1 has a problem in that the electrolyte vaporizes during the firing process, causing the battery to explode.

[0050] The step of forming the ionized water inlet 2 may also include the step of cutting open the battery to form a region into which an aqueous solution containing an ionic substance is injected. Specifically, the region into which the aqueous solution containing an ionic substance is injected may mean the cut surface. More specifically, the cut surface may mean a region having a three-dimensional space extending in the thickness direction of the cylindrical battery from a two-dimensional figure contained on the surface of the pouch-type or rectangular battery.

[0051] In one embodiment, if the battery is pouch-type or rectangular-type, the step of cutting open the battery can satisfy the following formula 1. <Expression 1> 0.02 ≤ L = [Incision Length] / [Total Surface Length] ≤ 0.9 (In Formula 1, [Cutting length] and [Overall surface length] respectively refer to the major axis length of the cut portion when the battery is cut and the major axis reference length of the battery.)

[0052] Formula 1 can be an index of stabilization in the pretreatment step of the pouch-type or square battery 1. Specifically, Formula 1 can satisfy 0.02 to 0.9. By making Formula 1 satisfy the above-mentioned range, the water discharge time can be appropriately maintained during the battery treatment process, and the recovery rate of black mass can be increased.

[0053] When Formula 1 is outside the lower limit value of the above-mentioned range, there is a problem that the conductivity of electrolyte ions is not transmitted during water discharge, and the water discharge time becomes long. When Formula 1 is outside the upper limit value of the above-mentioned range, although the water discharge time becomes short, the battery expands excessively, the battery surface is damaged, the internal positive or negative electrode material is discharged to the outside, and the recovery rate of black mass decreases.

[0054] In one embodiment, the cross-sectional area of the ion water inlet, which is the cut surface, can be 0.01 mm 2 or more. Specifically, the cross-sectional area can be 0.1 to 10.0 mm 2 , and more specifically, can satisfy 1.0 to 6.0 mm 2 .

[0055] In one embodiment, the pouch-type or square battery 1 can include an outer skin containing aluminum or iron; a positive electrode material and a negative electrode material disposed inside the outer skin. In one embodiment, the outer skin of the pouch-type or square battery 1 can have a thickness of 0.01 to 1.0 mm. In one embodiment, based on 100 at% of the battery outer skin, the total amount of Fe and Al in the outer skin of the pouch-type or square battery 1 can be 70 at% or more.

[0056] FIG. 2 is a drawing showing the step of forming a hole in a cylindrical battery according to an embodiment of the present invention. [[ID=!27]]

[0057] Referring to Figure 2, the step of cutting open the cylindrical battery 1 is shown. In one embodiment, the cylindrical battery 1 may include the step of forming at least one ionized water inlet 2 on its surface. The ionized water inlet 2 may be a component into which an aqueous solution containing an ionic substance is injected in order to discharge the battery of water. The cylindrical battery 1 has a problem in that the electrolyte vaporizes during the firing process, causing the battery to explode.

[0058] In one embodiment, the cross-sectional area of ​​the ion water inlet 2 is 0.01 mm². 2 The above is possible. Specifically, the cross-sectional area is 0.1 to 10.0 mm². 2 More specifically, 1.0~6.0mm 2 The following conditions can be met. When the cross-sectional area of ​​the ion water inlet 2 meets the aforementioned range, the formation of the hole is easy, and in a later process, ion water is rapidly injected into the battery, which has the advantage of shortening the discharge time. The horizontal cross-section of the hole can mean a three-dimensional space extending in the thickness direction of the cylindrical battery 1 from a two-dimensional figure contained on the surface of the cylindrical battery. The hole can have, for example, a circular or polygonal shape, and the hole can be described using terms such as a hole, gap, or crack.

[0059] In one embodiment, the depth of the hole may be 0.05 mm or more. The depth of the hole can also mean the vertical distance between the line segment and the surface of the cylindrical battery when an arbitrary line segment is drawn in a direction parallel to the horizontal direction 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.

[0060] Referring to Figures 1 and 2, in one embodiment, the number of ion water inlets 2 can range from 1 to 40. More specifically, the number of ion water inlets 2 can range from 2 to 30, and more specifically, from 2 to 15. By having the ion water inlets 2 within the aforementioned range, the injection of ion water during water discharge is facilitated, shortening the process time and enabling safe battery discharge.

[0061] In one embodiment, the step of forming the ion water inlet can be performed by various means such as a drill, punch, needle, laser, cutting device, compressive fracture, or shear fracture means to form a passage through which ions are injected.

[0062] In one embodiment, the cylindrical battery may include an outer casing containing iron, and positive and negative electrode materials disposed within the outer casing. The iron-containing outer casing may contain 60 at% or more iron, based on 100 at% of the casing.

[0063] <Example of experiment> Comparison of discharge rates according to the concentration of ionic substances introduced during water discharge. The discharge rate was compared using different types of ionic substances added to the aqueous solution during water discharge in a battery discharge method. The ionic substances added were NaCl, Na2SO4, and NaNO3. One side of a pouch-type battery was cut open, with the cut length set to 50% of the total length, and the L value adjusted to 0.5.

[0064] Furthermore, the temperature of the ionized water was maintained at approximately 20°C, and the discharge time and remaining voltage in the battery were measured.

[0065] Table 1 below shows the battery discharge time and remaining voltage according to the type and concentration of ionic substance. The concentration of the ionic substance refers to the concentration based on a 100 wt% aqueous solution, and the discharge time and remaining voltage were measured using the method described below. Discharge time: Measured using a digital timer device and a recoating method. Residual voltage: The voltage change over time was measured using a voltage recorder device.

[0066] [Table 1]

[0067] As shown in Table 2 above, it was confirmed that the discharge time decreases as the concentration of the same ionic substance in the aqueous solution increases. Furthermore, it was confirmed that the discharge efficiency increases in the order of NaCl, Na2SO4, and NaNO3.

[0068] Discharge rate with respect to temperature of ionized water The discharge rate of batteries was compared depending on the type of ionic substance added to the aqueous solution during water discharge. The ionic substances added during discharge were NaCl, Na2SO4, and NaNO3. One side of a pouch-type battery was cut open, with the cut length set to 50% of the total length and the L value set to 0.5. The ionic substance concentration was maintained at 10 wt%, and the discharge time and remaining voltage of the battery were measured while the ionized water temperature was varied as shown in Table 2 below.

[0069] [Table 2]

[0070] Referring to Table 3 above, it was confirmed that the discharge time decreased when the temperature of the ionized water to which each ionized substance was added was increased.

[0071] Ni recovery rate effect during the wet smelting process after the water discharge process, depending on the ionic substance. After a water discharge process for each ionic substance, the black mass containing the positive / negative electrode materials was recovered through a calcination process. Cl- and SO4 may remain in the black mass after the water discharge process for each ionic substance. 2- , and NO3 - To determine the impact of contained ionic substances within the acid-based wet smelting process, the Ni recovery rate was compared depending on the type of acid and ionic substance used in the wet smelting process.

[0072] The ionic substances introduced during battery discharge were NaCl, Na2SO4, and NaNO3. One side of the pouch-type battery was cut open, with the cut length being 50% of the total length, and the L value being 0.5. The ionic substance concentration was maintained at 10 wt%, the ionized water temperature was maintained at 20°C, and the firing temperature was maintained at 300°C.

[0073] Table 3 below shows the nickel recovery rates when calcined and acid leached, categorized by type of ionic substance.

[0074] [Table 3]

[0075] Referring to Table 3 above, the negative ion of the ionic substance is Cl - SO4 2- NO3 - We confirmed that the highest recovery rate can be achieved when leaching and recovering Ni using an acid containing negative ions that match (HCl, H2SO4, HNO3). This remains inside the black mass and is present in the aqueous solution during acid leaching using sulfuric acid or nitric acid. - SO4 2- NO3 - We confirmed that the presence of two or more negative ions makes pH adjustment, which is performed to remove impurities, difficult, leading to a problem where the recovery rate of valuable metals decreases.

[0076] Water discharge results by reusing Glauber's salt (Na2SO4)·10H2O Glauber's salt, which is generated in large quantities during the wet smelting and precursor manufacturing processes, is a typical by-product of the lithium-ion battery (LiB) waste battery recycling process. This Glauber's salt is an environmentally hazardous substance that causes soil contamination problems during landfill disposal.

[0077] The amount of sodium sulfate generated is approximately 2 to 3 times greater than the amount of substances introduced in the solvent extraction process of wet smelting. The present invention relates to the reuse of sodium sulfate, and was carried out by introducing the sodium sulfate as an ionic substance during the water discharge of a waste battery. At this time, the battery was a pouch-type battery, with one side cut open, the cut length was set to 50% of the total length, the L value was set to 0.5, the temperature of the ionized water was maintained at 20°C, and the discharge time and the remaining voltage in the battery were measured. After that, the recovery rate of Ni was evaluated after a calcination treatment at 300°C and an acid leaching process.

[0078] Table 4 below shows the nickel recovery rate from batteries under water discharge conditions.

[0079] [Table 4]

[0080] As shown in Table 4 above, when treated with sulfuric acid, sodium sulfate is SO4 2- We confirmed that there was no interference effect with ions, and that the recovery rate of valuable metals such as Li, Ni, and Co was superior compared to ionic substances such as NaCl and NaNO3. Thus, we confirmed that the example using Glauber's salt showed superior Ni recovery rate compared to other ionic substances during sulfuric acid treatment.

[0081] Although desirable embodiments have been described in detail above, the scope of the present invention is not limited thereto. Various modifications and improvements made by those skilled in the art, utilizing the basic concepts defined in the claims below, also fall within the scope of the present invention.

Claims

1. The present invention relates to a battery processing method that includes the step of discharging a waste battery containing lithium, Steps to prepare the battery; and The step includes discharging the battery with an aqueous solution containing a sulfate-based ion substance. The aforementioned sulfate-based ionic substance is a by-product generated in the waste battery recycling process, and the battery processing method.

2. The aforementioned sulfate-based ionic substance is sodium sulfate (Na ２ SO ４ The battery processing method according to claim 1, wherein the method is as follows:

3. The battery processing method according to claim 2, wherein the aforementioned sodium sulfate is a by-product generated in the wet smelting and precursor manufacturing process.

4. The battery processing method according to claim 1, wherein the step of discharging the battery with an aqueous solution containing a sulfate-based ionic substance is such that the concentration of the sulfate-based ionic substance is 5% by weight or more and 40% by weight based on 100% by weight of the aqueous solution.

5. The battery processing method according to claim 1, wherein the step of discharging the battery with an aqueous solution containing a sulfate-based ionic substance is wherein the temperature of the aqueous solution is 20°C or higher.

6. After the step of discharging water, The battery processing method according to claim 1, further comprising the step of firing the water discharged product at a temperature of 200°C or higher.

7. The battery processing method according to claim 6, further comprising the step of acid leaching the black mass that has undergone the aforementioned calcination step.

8. The battery treatment method according to claim 7, wherein the acid leaching is performed using sulfuric acid.

9. The battery processing method according to claim 1, wherein the step of preparing the battery includes the step of forming an ion water inlet in at least one battery that is cylindrical, pouch-shaped, or rectangular.

10. The battery processing method according to claim 10, wherein the step of forming the ion water inlet includes the step of cutting open the battery.

11. If the aforementioned battery is pouch-type or rectangular, The battery processing method according to claim 10, wherein the step of cutting open the battery satisfies the following formula 1. <Formula 1> 0.02 ≤ L = [Incision Length] / [Total Surface Length] ≤ 0.9 (In formula 1 above, [incision length] and [overall surface length] refer to the major axis length of the incision and the major axis reference length of the battery when the battery is incised, respectively.)

12. If the aforementioned battery is circular, The ion water inlet has a hole shape, The cross-sectional area of ​​the aforementioned hole is 0.01 mm². ２ The battery processing method according to claim 10.

13. The cross-sectional area of ​​the ion water inlet is 0.01 mm². ２ The battery processing method according to claim 11, as described above.

14. The battery processing method according to claim 12, wherein the depth of the ion water inlet is 0.05 mm or more.

15. The battery processing method according to claim 9, wherein the recovery rate of Ni recovered after the acid leaching step is 90% or more.

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