Battery disposal method including spent battery discharge method

Abstract

The present invention relates to a battery treatment method, and more particularly to a battery treatment method including a discharge method of a lithium-containing waste battery, which includes a step of preparing a battery; and a step of performing water discharge on the battery in an aqueous solution including a sulfuric acid-based ionic substance, which is a by-product generated in a waste battery recycling process.

Description

Technical Field

[0001] This invention relates to a battery processing method, and more specifically to a battery processing method including a discharge method for a lithium-ion battery. Background Technology

[0002] With the increasing global demand for electric vehicles, the disposal of waste batteries generated by these vehicles has become a social problem. Lithium-ion batteries, which are the main raw material for these waste batteries, contain organic solvents, explosive substances, and heavy metals such as Ni, Co, Mn, and Fe. However, Ni, Co, Mn, and Li are valuable metals with significant scarcity value, making the recycling and reuse processes of discarded lithium-ion batteries an important research area.

[0003] Specifically, a lithium secondary battery mainly consists of copper and aluminum as current collectors, oxides containing Li, Ni, Co, Mn, Fe, Al, and P constituting the positive electrode material, and graphite as the negative electrode material. It also includes a separator for separating the positive and negative electrode materials and an electrolyte injected into the separator. The solvents used as the solvent and salt in the electrolyte are primarily mixed organic carbonate compounds such as ethylene carbonate, propylene carbonate, and, for example, LiPF6.

[0004] To utilize these waste batteries, a reuse process that safely discharges them before pulverizing them is under active development. After discharge, the waste batteries undergo drying and calcination to remove internal moisture and electrolytes. Following drying and calcination, a black powder containing Li, Ni, Co, Mn, Fe, P, Al, Cu, and graphite is produced through crushing, peeling, and particle size screening.

[0005] At this point, there are many methods for discharging lithium-containing waste batteries, such as water discharge using water as a medium and electro-discharge methods. For water discharge, the battery body is immersed in water as a medium, forcing the lithium-ion battery to discharge. With water discharge, due to the forced disconnection, the electrolyte leaks from the battery and floats on the water surface. When excessive water discharge causes the water temperature to rise, the electrolyte may ignite, posing a risk of a fire even during water discharge. Water discharge also has the problem of a longer discharge time compared to electro-discharge. Furthermore, because water discharge utilizes the ionic conductivity of water for forced discharge, the discharge rate may be slower compared to methods like electro-discharge that apply external voltage. However, with water discharge, no voltage rebound phenomenon has been observed after discharge, so subsequent processes such as crushing and particle size screening can be safely performed to recover valuable metals from the battery.

[0006] For this type of water discharge, the discharge rate can be increased by dissolving substances with high ionic conductivity. While NaCl is used as the substance with high ionic conductivity, it remains inside the battery and generates Na or Cl gas during the calcination and drying processes, potentially causing equipment corrosion. Furthermore, due to residues inside the black powder obtained after crushing and particle size screening, more than two types of Cl- anions will remain in the aqueous solution during acid leaching with sulfuric or nitric acid. - SO4 2- Or NO3 - This makes pH adjustment for impurity removal difficult and leads to a decrease in the recovery rate of valuable metals.

[0007] To address these issues, it is necessary to research a NaCl alternative that improves the ionic conductivity in aqueous solutions and accelerates the discharge rate during battery water discharge, while minimizing the solid residue remaining after drying and calcination processes. Summary of the Invention

[0008] Technical problems to be solved The technical problem to be solved by the present invention is to provide a battery processing method, which includes a method for discharging lithium-containing batteries using a NaCl substitute. The NaCl substitute improves the ionic conductivity in the aqueous solution and accelerates the discharge rate during battery water discharge, while minimizing the solid residue remaining after drying and calcination processes.

[0009] Technical solution One embodiment of the present invention relates to a battery treatment method including the step of discharging lithium-containing waste batteries, comprising: a step of preparing the battery; and a step of water discharge of the battery in an aqueous solution containing sulfate ions, wherein the sulfate ions may be a byproduct generated in the waste battery recycling process.

[0010] In one embodiment, the sulfate-like ionic substance may be sodium sulfate (Na2SO4). In another embodiment, the sodium sulfate may be a byproduct generated during wet refining and precursor manufacturing processes.

[0011] In one embodiment, in the step of water discharge of the battery in an aqueous solution containing sulfate ions, the concentration of the sulfate ions, based on 100% by weight of the aqueous solution, may be 5% by weight or more to 20% by weight. In one embodiment, in the step of water discharge of the battery in an aqueous solution containing sulfate ions, the temperature of the aqueous solution may be 20°C or higher.

[0012] In one embodiment, after the water discharge step, a step of calcining the water discharge product at a temperature above 200°C may be included. In one embodiment, a step of acid leaching the black mass after the calcination step may be included. In one embodiment, the acid leaching may utilize sulfuric acid.

[0013] In one embodiment, the battery preparation step may include forming an ionized water injection port on at least one of cylindrical, pouch-shaped, and square batteries. In one embodiment, the ionized water injection port forming step may include cutting the battery.

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

[0015] <Formula 1> 0.02 ≤ L = [cut length] / [total surface length] ≤ 0.9 In Equation 1 above, [cut length] and [total surface length] represent the length of the major axis of the cut portion and the standard length of the major axis of the battery, respectively.

[0016] In one embodiment, when the battery is circular, the ionized water injection port has a hole shape, and the cross-sectional area of ​​the hole can be 0.01 mm. 2 The above. In one embodiment, the cross-sectional area of ​​the ionized water injection port can be 0.01 mm. 2The above. In one embodiment, the depth of the ionized water injection port can be 0.05 mm or more. In one embodiment, the recovery rate of Ni recovered after the acid leaching step can be 90% or more.

[0017] Beneficial effects According to an embodiment of the present invention, a battery processing method includes a battery discharge method that uses sodium sulfate (Na2SO4) as an additive to improve the ionic conductivity in the aqueous solution during water discharge, thereby improving the ionic conductivity in the aqueous solution during battery water discharge and accelerating the discharge rate, while minimizing the solid residue remaining after drying and calcination processes. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating the steps of forming a cut surface on a pouch-shaped or square battery according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram illustrating the steps of forming a hole in a cylindrical battery according to an embodiment of the present invention. Detailed Implementation

[0020] The terms "first," "second," "third," etc., are used to describe parts, components, regions, layers, and / or segments, but these parts, components, regions, layers, and / or segments should not be limited by these terms. These terms are only used to distinguish one part, component, region, layer, or segment from another. Therefore, without departing from the scope of the invention, the first part, component, region, layer, or segment described below can also be described as a second part, component, region, layer, or segment.

[0021] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. Unless the context clearly indicates otherwise, the singular forms used herein are intended to include the plural forms as well. The word "comprising" as used in the specification can specifically refer to a feature, field, integer, step, action, element, and / or component, but does not exclude the presence or addition of other features, fields, integers, steps, actions, elements, and / or components.

[0022] If one part is described as being on top of another part, then other parts may exist directly on top of or in between the other part. If one part is described as being directly on top of another part, then no other parts exist in between.

[0023] Furthermore, % in this specification represents weight percentage, unless otherwise stated.

[0024] Although not otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in dictionaries should be interpreted as having the same meaning as disclosed in relevant technical literature and herein, and should not be interpreted in an idealized or overly formal sense.

[0025] Embodiments of the present invention will be described in detail below. However, the following embodiments are given by way of example only, and the present invention is not limited to the following embodiments; the present invention is defined only by the scope of the claims.

[0026] A battery processing method according to an embodiment of the present invention relates to a battery processing method including the step of discharging lithium-containing waste batteries. Specifically, the battery processing method of the present invention includes a step of preparing the battery and a step of water discharging the battery in an aqueous solution containing sulfate ions.

[0027] The steps for preparing a battery can be the same as those for preparing a used battery. For example, the battery can be a lithium secondary battery separated from a car, or a secondary battery separated from electronic devices such as mobile phones, cameras, and laptops; specifically, it can be a lithium secondary battery.

[0028] In one embodiment, during the battery preparation step, the battery may include at least one of cylindrical, pouch, and prismatic shapes. Specifically, the battery may refer to at least one individual battery cell within a battery pack or battery module.

[0029] The step of water discharge of a battery in an aqueous solution containing sulfate ions can be either immersing the battery in the aqueous solution containing sulfate ions or injecting the aqueous solution into the battery and then discharging the battery.

[0030] Specifically, regarding the battery, when the energy stored in the battery body is disconnected, as shown in the following reaction formula, a large amount of heat may be generated due to a sharp increase in current at extremely low resistance. This large amount of heat will heat the flammable electrolyte material, thus posing a risk of fire or explosion.

[0031] [Reaction Formula] H = Joule heat = I 2 / R Δt (I = current, R = resistance, Δt = exposure time of wire breakage) In addition, similar to traditional methods, water discharge of the battery by NaCl and other ionic substances through salt water discharge can suppress the heating reaction caused by wire breakage during forced discharge. However, there are problems with the generation of harmful HF gas and F dissolved wastewater, which are produced when fluorine dissolved in the electrolyte is vaporized (Gas) during discharge.

[0032] In one embodiment of the invention, the process includes a step of water discharge of the battery in an aqueous solution containing sulfuric acid ions, wherein the ions are reduced in the leaching step during sulfuric acid treatment with SO4. 2- The interference effect of ions can suppress the formation of harmful gases, while minimizing the solid residue remaining after drying and calcination processes.

[0033] In one embodiment, the sulfate-like ionic substance can be sodium sulfate (Na₂SO₄). The sodium sulfate can be a byproduct generated during the waste battery recycling process. Specifically, the sodium sulfate is a typical byproduct generated during the waste battery recycling process, particularly during the wet refining and precursor manufacturing processes. The sodium sulfate is partially contaminated by Ni, Co, Mn, Li, etc., during the wet refining and precursor manufacturing processes, and compared to currently used sodium sulfate, it has a higher impurity content. These substances can be less than 1% in the sodium sulfate.

[0034] The amount of Glauber's salt produced is approximately 2 to 3 times that of the substances added during solvent extraction in wet refining, posing a problem of soil pollution as an environmentally harmful substance when buried in the ground. In the battery treatment method of the present invention, the Glauber's salt is reused as a sulfate-like ionic substance, thereby providing an environmentally friendly, economical battery treatment method that minimizes side reactions with sulfuric acid in subsequent processes.

[0035] In one embodiment, during the water discharge step of the battery in an aqueous solution containing sulfate ions, the concentration of the sulfate ions, based on 100% by weight of the aqueous solution, can be from 5% by weight to 40% by weight. Specifically, the concentration of the sulfate ions can be from 8.5% to 30% by weight, more specifically, from 10% to 25% by weight, further specifically, from 9% to 20% by weight, and even more specifically, from 10% to 15% by weight.

[0036] By ensuring the concentration of the sulfate ions remains within the aforementioned range, an appropriate discharge rate can be maintained, allowing the battery to discharge safely. If the concentration exceeds the upper limit of the aforementioned range, the excessively rapid discharge rate will cause the temperature of the ionized water to rise, increasing the risk of fire. If the concentration exceeds the lower limit of the aforementioned range, a delay in the discharge rate will occur.

[0037] In one embodiment, during the step of water discharge of the battery in an aqueous solution comprising sulfate-like ions, the temperature of the aqueous solution may be above 20°C. Specifically, the temperature may be between 20 and 80°C. More specifically, the temperature may be between 40 and 80°C, and even more specifically, between 60 and 80°C.

[0038] By ensuring the temperature falls within the aforementioned range, the discharge rate can be increased at the same concentration. If the temperature exceeds the upper limit of the aforementioned range, over-discharge leads to a temperature rise and evaporation of ionized water, increasing the risk of fire. If the temperature exceeds the lower limit of the aforementioned range, the movement of ionized matter slows down, resulting in a discharge time delay.

[0039] In one embodiment, after the water discharge step, a step of calcining the water discharge product at a temperature above 200°C may be included. Specifically, in the step of calcining the water discharge product within the aforementioned temperature range, the temperature range may be 200 to 500°C, more specifically, 200 to 400°C, and even more specifically, 250 to 350°C. The calcination step may be a step to remove residual ionized water or electrolytes from the battery by evaporating them after the water discharge of the battery using ionized water.

[0040] Because the temperature of the calcination step meets the aforementioned temperature range, the residual liquid phase material inside the battery completely evaporates, thus improving safety during battery processing. If the temperature of the calcination step exceeds the upper limit of the aforementioned range, there is a problem of generating harmful gases such as H2 or SO2. If the temperature of the calcination step exceeds the lower limit of the aforementioned range, there is a problem of the liquid phase material inside the battery being difficult to remove.

[0041] In one embodiment, prior to the calcination step, a step of breaking the battery may be included. The battery breaking step may be a step of applying external force to the battery after it has undergone a discharge process to break it. Specifically, the battery breaking step may refer to a process in which an impact or pressure is applied to the battery, causing a portion of the battery to detach from the battery.

[0042] In one embodiment, the battery crushing step may refer to all processes of pulverizing batteries, cutting batteries, compressing batteries, and combinations thereof. Specifically, the crushing step may include all processes capable of destroying the battery to obtain small-sized fragments.

[0043] In one embodiment, the battery crushing step may include any process of compressing the battery or applying external forces such as shearing or tensile forces to destroy the battery. For example, the battery crushing step may be carried out using a crusher.

[0044] In one embodiment, the battery breaking step may be performed at least once. Specifically, the breaking step may be performed continuously or discontinuously at least once.

[0045] In one embodiment, the battery crushing step can be carried out under conditions of supplying inert gas, carbon dioxide, nitrogen, water, or a combination thereof, or under vacuum conditions below 100 Torr. Crushing in this environment prevents battery explosion and suppresses electrolyte vaporization, thus preventing the generation of flammable gases such as ethylene, propylene, or hydrogen. Including the battery crushing step improves process efficiency in subsequent drying or calcination steps.

[0046] In one embodiment, the process may include an acid leaching step of the black mass resulting from the calcination step. Specifically, the acid leaching step may be a step using sulfuric acid. More specifically, it may be a step of recovering valuable metals by leaching the black mass in sulfuric acid.

[0047] In one embodiment, the acid leaching step may further include a reducing agent. Specifically, the acid leaching step may be a step in which a reducing agent is further added to an acidic solution to recover valuable metals from the ferrous substance. 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.

[0048] In one embodiment, the recovery rate of Ni recovered after the acid leaching step can be above 90%. As described above, by adding sodium sulfate as an ionic substance during water discharge, interference with sulfuric acid in the acid leaching step can be minimized, thereby improving the recovery rate of the valuable metal Ni.

[0049] Figure 1 This is a schematic diagram illustrating the steps of forming a cut surface on a pouch-shaped or square battery according to an embodiment of the present invention.

[0050] Reference Figure 1 The diagram illustrates the steps of cutting open a pouch cell or prismatic battery. In one embodiment, the pouch cell or prismatic battery 1 may include the step of forming at least one ionized water injection port 2 on its surface. The ionized water injection port 2 may be a component for injecting an aqueous solution containing ionic substances to enable the battery to perform water discharge. Specifically, the ionized water injection port 2 may be a region for injecting an aqueous solution containing the ionic substances so that ionized water can be easily injected during the water discharge process of the battery. The prismatic or pouch cell 1 has the problem of electrolyte vaporization during calcination, which can lead to battery explosion.

[0051] For the step of forming the ionized water injection port 2, by including the step of cutting the battery, a region for injecting an aqueous solution containing ionic substances can be formed. Specifically, the region for injecting the aqueous solution containing the ionic substances can refer to the cut surface. More specifically, the cut surface can refer to a three-dimensional region extending along the thickness direction of the cylindrical battery from a two-dimensional pattern included in the surface of the pouch or square battery.

[0052] In one embodiment, when the battery is pouch-shaped or square, the step of cutting the battery can satisfy the following formula 1.

[0053] <Formula 1> 0.02 ≤ L = [cut length] / [total surface length] ≤ 0.9 In Equation 1 above, [cut length] and [total surface length] represent the length of the major axis of the cut portion and the standard length of the major axis of the battery, respectively.

[0054] Equation 1 above can be a stabilization index in the pretreatment step of the pouch or prismatic battery 1. Specifically, Equation 1 above can satisfy 0.02 to 0.9. By satisfying the aforementioned range in Equation 1 above, the water discharge time can be appropriately maintained during battery processing, and the recovery rate of black mass can be improved.

[0055] If Equation 1 exceeds the lower limit of the aforementioned range, the electrolyte ion conductivity cannot be transferred during water discharge, resulting in a longer water discharge time. If Equation 1 exceeds the upper limit of the aforementioned range, the water discharge time is shortened, but excessive battery expansion damages the battery surface, causing internal positive or negative electrode materials to escape, leading to a decrease in the recovery rate of black substances.

[0056] In one embodiment, the cross-sectional area of ​​the ionized water injection port, which serves as the cut surface, can be 0.01 mm. 2 That's all. Specifically, the cross-sectional area can be between 0.1 and 10.0 mm². 2 More specifically, it can meet the requirements of 1.0 to 6.0 mm. 2 .

[0057] In one embodiment, the pouch-shaped or prismatic battery 1 may include: a casing comprising aluminum or iron; a positive electrode material and a negative electrode material disposed within the casing. In one embodiment, the casing of the pouch-shaped or prismatic battery 1 may have a thickness of 0.01 to 1.0 mm. In one embodiment, for the casing of the pouch-shaped or prismatic battery 1, the total amount of Fe and Al, based on 100 at% of the battery casing, may be 70 at% or more.

[0058] Figure 2This is a schematic diagram illustrating the steps of forming a hole in a cylindrical battery according to an embodiment of the present invention.

[0059] Reference Figure 2 The diagram illustrates the steps of cutting open a cylindrical battery 1. In one embodiment, the cylindrical battery 1 may include the step of forming at least one ionized water injection port 2 on its surface. The ionized water injection port 2 may be a component for injecting an aqueous solution containing ionic substances to cause the battery to discharge water. The cylindrical battery 1 has the problem of electrolyte vaporization during calcination, which can lead to battery explosion.

[0060] In one embodiment, the cross-sectional area of ​​the ionized water injection port 2 can be 0.01 mm². 2 That's all. Specifically, the cross-sectional area can be between 0.1 and 10.0 mm². 2 More specifically, it can meet the requirements of 1.0 to 6.0 mm. 2 When the cross-sectional area of ​​the ionized water injection port 2 meets the aforementioned range, the hole is easily formed, allowing ionized water to be rapidly injected into the battery during subsequent processes, thus shortening the discharge time. The horizontal cross-section of the hole can refer to a three-dimensional space extending along the thickness direction of the cylindrical battery 1 from a two-dimensional pattern included in the surface of the cylindrical battery. The hole can be, for example, circular or polygonal in shape. The term "hole" can include, for example, terms such as aperture, gap, or crack.

[0061] In one embodiment, the depth of the hole may be 0.05 mm or more. The depth of the hole can refer to the vertical distance between the line segment drawn relative 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, more specifically, 0.5 to 1.0 mm.

[0062] Reference Figure 1 and Figure 2 In one embodiment, the number of ionized water injection ports 2 can be from 1 to 40. Specifically, the number of ionized water injection ports 2 can be from 2 to 30, and more specifically, from 2 to 15. Because the number of ionized water injection ports 2 meets the aforementioned range, ionized water can be easily injected during water discharge, shortening the process time and allowing the battery to be discharged safely.

[0063] In one embodiment, the ion water injection port forming step can be achieved by various means such as drilling, punching, needle punching, laser, cutting machine, compression or shearing to form an ion injection channel.

[0064] In one embodiment, the cylindrical battery may include an iron-containing casing and positive and negative electrode materials disposed within the casing. The iron-containing casing may contain more than 60 at% iron, based on a casing weight of 100 at%.

[0065] <Experimental Example> Compare the discharge rates based on the concentration of ions added during water discharge. The discharge rates were compared based on the types of ionic substances added to the aqueous solution during water discharge using a battery discharge method. The added ionic substances were NaCl, Na₂SO₄, and NaNO₃. One side of the pouch battery was cut open, with the cut length adjusted to 50% of the total length, and the L value adjusted to 0.5.

[0066] In addition, the temperature of the deionized water was maintained at approximately 20°C, and the discharge time and residual voltage within the battery were measured.

[0067] Table 1 below shows the battery discharge time and residual voltage based on the type and concentration of ionic substances. The concentration of ionic substances refers to the concentration based on 100 wt% aqueous solution. The discharge time and residual voltage were determined using the methods described below.

[0068] Discharge time: Measured using a digital timer device and recording method.

[0069] Residual voltage: The voltage change over time was measured using a voltage recording device.

[0070] Table 1

[0071] Table 2 confirms that for the same ionic substance, the higher the concentration in aqueous solution, the shorter the discharge time. Furthermore, the discharge efficiency has been confirmed to increase in the order of NaCl, Na₂SO₄, and NaNO₃.

[0072] Based on the discharge rate of ionized water temperature The discharge rates of batteries were compared based on the types of ionic substances added to the aqueous solution during water discharge. The ionic substances added during discharge were NaCl, Na₂SO₄, and NaNO₃. One side of the pouch battery was cut open, with a cut length of 50% of the total length and an L value of 0.5. The concentration of ionic substances was maintained at 10 wt%. The temperature of the deionized water was varied, as shown in Table 2, and the discharge time and residual voltage of the batteries were measured.

[0073] Table 2

[0074] Referring to Table 3 above, it has been confirmed that the discharge time decreases when the temperature of the ionized water containing each ionic substance increases.

[0075] Effects of different ionic substances on Ni recovery rate in wet refining process after water discharge process Black matter containing positive / negative electrode materials was recovered by calcination after the water discharge process, based on different ionic substances. This was done to identify possible Cl-containing compounds remaining in the black matter after the water discharge process. - SO4 2- and NO3 - The influence of ionic substances on acid-based wet refining processes was investigated, and the Ni recovery rate was compared based on the type of acid used in the wet refining process and the ionic substances.

[0076] The ionic substances added during battery discharge are NaCl, Na2SO4, and NaNO3. One side of the pouch battery is cut open, with a cut length of 50% of the total length and an L value of 0.5. The concentration of the ionic substances is maintained at 10 wt%, the temperature of the deionized water is maintained at 20℃, and the calcination treatment temperature is maintained at 300℃.

[0077] Table 3 below shows the nickel recovery rates during calcination and acid leaching, depending on the type of ionic substance.

[0078] Table 3

[0079] Referring to Table 3 above, it is confirmed that anions containing ionic substances, such as Cl, are used. - SO4 2- NO3 - The highest recovery rate can be ensured when leaching with consistent anionic acids (HCl, H₂SO₄, HNO₃) to recover Ni. This indicates that Cl₂ remains in the aqueous solution due to residues inside the black substance, even after acid leaching with sulfuric or nitric acid. - SO4 2- NO3 - When two or more anions are present, pH adjustment for impurity removal becomes difficult, leading to a decrease in the recovery rate of valuable metals.

[0080] Results of water discharge for the recovery and reuse of Glauber's salt (Na2SO4·10H2O) Glauber's salt, which is produced in large quantities during wet refining and precursor manufacturing processes, is a typical byproduct of the recycling of LiB waste batteries. Glauber's salt is an environmentally harmful substance and a byproduct that causes soil pollution problems during landfilling.

[0081] The amount of Glauber's salt produced is approximately 2 to 3 times that of the substance added in the solvent extraction process of wet refining. This invention relates to the reuse of Glauber's salt, which is added as an ionic substance during the discharge of waste batteries. In this case, the battery is a pouch cell, one side is cut open, with a cut length of 50% of the total length, an L value of 0.5, and the temperature of the deionized water is maintained at 20°C. The discharge time and residual voltage within the battery are measured. Subsequently, after calcination at 300°C and acid leaching, the recovery rate of Ni is evaluated.

[0082] Table 4 below shows the nickel recovery rate from the battery based on water discharge conditions.

[0083] Table 4

[0084] As confirmed in Table 4 above, Glauber's salt does not react with SO4 during sulfuric acid treatment. 2- The interference effect of ions is that the recovery rate of valuable metals such as Li, Ni, and Co is better than that of ionic substances such as NaCl and NaNO3. As mentioned above, in the example using Glauber's salt, the Ni recovery rate is better than that of other ionic substances when treated with sulfuric acid.

[0085] The preferred embodiments have been described in detail above, but the scope of the present invention is not limited to the above embodiments. Various modifications and improvements made by those skilled in the art using the basic concepts defined in the claims also fall within the scope of the present invention.

Claims

1. A battery processing method, comprising the step of discharging lithium-containing waste batteries, the battery processing method comprising: Steps for preparing batteries; as well as The step of performing water discharge on the battery in an aqueous solution containing sulfate ions. The sulfate-like ions are byproducts generated during the recycling process of waste batteries.

2. The battery processing method according to claim 1, wherein, The sulfate-like ionic substance mentioned is sodium sulfate (Na2SO4).

3. The battery processing method according to claim 2, wherein, The sodium sulfate is a byproduct of wet refining and precursor manufacturing processes.

4. The battery processing method according to claim 1, wherein, In the step of water discharge of the battery in an aqueous solution containing sulfate ions, the concentration of the sulfate ions is 5% to 40% by weight, based on 100% by weight of the aqueous solution.

5. The battery processing method according to claim 1, wherein, In the step of performing water discharge on the battery in an aqueous solution containing sulfate ions, the temperature of the aqueous solution is above 20°C.

6. The battery processing method according to claim 1, wherein, This includes a step of calcining the water discharge product at a temperature above 200°C after the water discharge step.

7. The battery processing method according to claim 6, comprising: The step of acid leaching the black substance obtained after the calcination step.

8. The battery processing method according to claim 7, wherein, The acid leaching process utilizes sulfuric acid.

9. The battery processing method according to claim 1, wherein, The battery preparation steps include forming an ionized water injection port in at least one of cylindrical, pouch-shaped, and square batteries.

10. The battery processing method according to claim 10, wherein, The step of forming the ionized water injection port includes the step of cutting open the battery.

11. The battery processing method according to claim 10, wherein, When the battery is a pouch or a square shape The step of cutting the battery satisfies the following equation 1. <Formula 1> 0.02 ≤ L = [cut length] / [total surface length] ≤ 0.9 In Equation 1 above, [cut length] and [total surface length] represent the length of the major axis of the cut portion and the standard length of the major axis of the battery, respectively.

12. The battery processing method according to claim 10, wherein, When the battery is round The ionized water injection port has a hole shape. The cross-sectional area of ​​the hole is 0.01 mm. 2 above.

13. The battery processing method according to claim 11, wherein, The cross-sectional area of ​​the ionized water injection port is 0.01 mm. 2 above.

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

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

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