Recycling method of cylindrical battery

Abstract

A recycling method of a cylindrical battery, according to the present invention, comprises the steps of: preparing a cylindrical battery; forming at least one gas outlet in the surface of the cylindrical battery; heating the cylindrical battery having the gas outlet; obtaining a crushed material by crushing the heated cylindrical battery; and obtaining a recovered material by separating the crushed material.

Description

How to Recycle Cylindrical Batteries

[0001] The present invention relates to a method for recycling a cylindrical battery, and more particularly, to a method for recycling a cylindrical battery by high-temperature reduction.

[0002] The issue of disposing of spent electric vehicle batteries is becoming a social issue worldwide. Lithium-ion batteries contain flammable and / or explosive substances, such as organic solvents, and heavy metals such as Ni-Co-Mn-Fe. Among these, Ni, Co, Mn, and Li are highly valuable metals with significant scarcity value. Therefore, the disposal of lithium secondary batteries and subsequent recovery and recycling processes are becoming crucial.

[0003] Meanwhile, the battery structure for electric vehicles can be divided into cell, module, and pack units. For example, cells with voltages of 2 to 4 V are connected in series or parallel to form modules with voltages of 20 to 60 V. Multiple modules are then connected in series to form a pack.

[0004] The composition of a lithium-ion battery for an electric vehicle is mainly composed of, for example, Cu, Al used as a current collector / Li-Ni-Co-Mn-Fe-P oxide used as a cathode material and graphite used as an anode material, a separator that separates the cathode and anode materials, and an electrolyte injected into the separator.

[0005] The electrolyte is, for example, a solvent and a salt. The solvent is mainly a mixture of organic carbonates such as ethylene carbonate / propylene carbonate, and the salt can mainly be LiPF6 (Lithium hexafluorophosphate).

[0006] The operating principle of a lithium-ion battery is as follows. When Li ions located within the oxide composed of Li-Ni-Co-Mn-Fe-P, which constitutes the positive electrode, move to the negative electrode due to an external charge, the electrons move to the negative electrode through the separator in which the electrolyte is injected, located between the positive and negative electrode materials, in order to satisfy charge neutrality, and are located on the graphite of the negative electrode material. This process is the charging process, and in the opposite direction, when electrons move to the positive electrode through the external circuit, the Li ions move to the oxide structure within the positive electrode material within the electrolyte, which is called the discharging process.

[0007] At this time, in the case of NCM type lithium ion batteries, the positive electrode material is composed of Li-Ni-Co-Mn-O, and Al can be used as the current collector of the positive electrode material. The negative electrode material is C and can be coated on a Cu current collector. When the positive electrode material and the negative electrode material are overlapped and raised to a high temperature of 700℃ or higher, a reduction reaction by C occurs, and when the temperature is raised above 1050℃, Cu melts, or when it is above 1250℃, Ni melts and becomes an alloy state of the surrounding Ni-Cu-Co-Mn-C. At this time, when the oxygen concentration during the reaction is 1000ppm or more, the concentration of C in the alloy drops rapidly.

[0008] Conventional battery recycling methods involve discharging and crushing spent cylindrical batteries, then recovering a black powder of Ni-Co-Mn-O from the resulting waste. This powder is then treated with acid to recover valuable metals. However, cylindrical batteries have an iron outer shell, making them difficult to crush. Furthermore, even after crushing, the internal materials remain difficult to extract, resulting in low recovery rates.

[0009] In addition, the existing high-temperature heat treatment method melts and recovers cylindrical batteries at a high temperature of about 1500℃, which causes some problems with lithium loss and the iron outer shell of the cylindrical battery melting together, which causes a burden on the subsequent acid treatment process.

[0010] Therefore, there is a need to develop a recycling method for cylindrical batteries that can increase the recovery rate and prevent explosion due to electrolyte vaporization.

[0011] The present invention is a method for high-temperature reduction of a cylindrical battery, and aims to provide a method for recycling a cylindrical battery that can suppress explosion due to vaporization of electrolyte within the cylindrical battery and increase the recovery rate of recovered materials.

[0012] The present invention provides a method for recycling a cylindrical battery, comprising the steps of: preparing a cylindrical battery; forming at least one gas exhaust port on the surface of the cylindrical battery; heating the cylindrical battery having the gas exhaust port formed thereon; crushing the heated cylindrical battery to obtain shredded material; and separating the shredded material to obtain recovered material.

[0013] The method for recycling cylindrical batteries according to the present invention is a method for high-temperature reduction of cylindrical batteries, thereby suppressing explosions caused by electrolyte vaporization within the cylindrical battery. By preventing overheating due to explosion, lithium volatilization, which typically begins at temperatures above 1,300°C, can be suppressed, thereby increasing the recovery rate of valuable metals.

[0014] FIG. 1 is a diagram illustrating a step of forming a hole in a cylindrical battery according to some embodiments of the present invention.

[0015] FIG. 2 is a graph showing the reduction rate according to the heating time of a cylindrical battery in a method for recycling a cylindrical battery according to some embodiments of the present invention.

[0016] Figures 3 and 4 are diagrams showing shredded material and recovered material obtained according to a method for recycling a cylindrical battery according to some embodiments of the present invention.

[0017] Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and are not intended to limit the present invention. The present invention is defined solely by the scope of the claims set forth below.

[0018] In the present invention, when it is said that a member is located “on” another member, this includes not only cases where a member is in direct contact with another member, but also cases where another member is interposed between the two members.

[0019] When a part of the present invention is said to "include" a certain component, this does not mean that other components are excluded, but rather that other components may be included, unless otherwise specifically stated.

[0020]

[0021] One aspect of the present invention relates to a method for recycling a cylindrical battery (1), comprising the steps of: preparing a cylindrical battery (1); forming at least one gas exhaust port (2) on the surface of the cylindrical battery (1); heating the cylindrical battery (1) having the gas exhaust port (2) formed thereon; crushing the heated cylindrical battery (1) to obtain shredded material; and separating the shredded material to obtain recovered material.

[0022] Lithium secondary batteries are being widely used in a wide range of applications, from small electronic devices to automobiles. Their primary components are nickel, cobalt, manganese, and lithium, making them expensive elements. However, lithium secondary batteries typically last between five and ten years before their rechargeable capacity diminishes, reaching the end of their lifespan. Recycling these components has become essential for environmental and cost reasons.

[0023] Accordingly, in the present invention, as a method for high-temperature reduction of a cylindrical battery (1), in order to prevent an explosion due to vaporization of an electrolyte within the cylindrical battery (1), a step is included of forming at least one gas exhaust port (2) on the surface of the cylindrical battery (1), heating the cylindrical battery (1) through induction heating or resistance heating, and then crushing the heated cylindrical battery (1) and separating the crushed material to recover the recovered material.

[0024]

[0025] Steps to prepare a cylindrical battery

[0026] A method for recycling a cylindrical battery (1) according to the present invention includes a step of preparing a cylindrical battery (1).

[0027] The above cylindrical battery (1) may be of a type that includes an outer shell containing iron and includes a positive electrode material and a negative electrode material inside.

[0028] Specifically, the cylindrical battery (1) according to the present invention may include an outer shell containing iron. In short, the present invention may relate to a method for recycling a cylindrical battery (1) including an outer shell containing iron.

[0029] The above cylindrical battery (1) may be referred to as a waste cylindrical battery.

[0030] In one embodiment of the present invention, the cylindrical battery (1) may have an outer shell having a thickness of 0.05 to 1 mm, and the outer shell may include an alloy having an Fe content of 60 at% or more.

[0031]

[0032] A step of forming at least one gas outlet on the surface of a cylindrical battery.

[0033] A method for recycling a cylindrical battery (1) according to the present invention includes a step of forming at least one gas exhaust port (2) on the surface of the cylindrical battery (1).

[0034] There is a possibility that the cylindrical battery (1) may explode due to the vaporization of the electrolyte during the heating process.

[0035] Referring to FIG. 1, the method for recycling a cylindrical battery (1) according to the present invention has the advantage of being able to suppress explosion through gas discharge by including a step of forming at least one gas discharge port (2) on the surface of the cylindrical battery (1).

[0036] Specifically, the surface of the cylindrical battery (1) includes at least one gas outlet (2).

[0037] In the present invention, the “gas discharge port (2)” may refer to a discharge port for discharging gas generated in the process of heating the cylindrical battery (1).

[0038]

[0039] In another embodiment of the present invention, the step of forming the gas outlet (2) may include the step of forming at least one hole (2) on the surface of the cylindrical battery (1).

[0040] In another embodiment of the present invention, the step of forming the gas exhaust port (2) may include the step of cutting a part of the cylindrical battery (1).

[0041] In short, the gas outlet (2) may be formed by forming at least one hole (2) in the cylindrical battery (1), or may be formed by cutting a part of the cylindrical battery (1).

[0042] In another embodiment of the present invention, in the step of forming the hole (2), the hole (2) has a cross-sectional area of ​​0.01 mm. 2 It may be formed to become ideal.

[0043] In another embodiment of the present invention, the hole (2) has a cross-sectional area of ​​0.1 to 10 mm. 2 , preferably 1 to 6 mm 2 It may be formed to be like this.

[0044] When the cross-sectional area of ​​the above hole (2) satisfies the above range, it is preferable that the hole (2) be formed easily and that the gas generated when the cylindrical battery (1) is heated later can sufficiently escape.

[0045]

[0046] In the present invention, “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 (1).

[0047] The horizontal cross-section of the hole (2) on the surface of the cylindrical battery (1) may have one or more shapes selected from the group consisting of circles and polygons.

[0048] In short, the horizontal cross-section of the above hole (2) does not have a specific shape as long as the cross-sectional area satisfies the above range.

[0049] In the present invention, “hole” may be a term encompassing holes, gaps and / or cracks.

[0050] In the present invention, “horizontal cross-section” may mean a surface cut in a direction parallel to the surface of the cylindrical battery (1) through which the hole (2) is penetrated.

[0051] In the present invention, “cross-sectional area of ​​a hole” may mean the cross-sectional area of ​​a horizontal cross-section included in the surface of the cylindrical battery (1) through which the hole (2) is penetrated.

[0052] The cross-sectional area of ​​the above hole (2) can be measured as the product of the maximum length and width in the tangent direction perpendicular to the thickness of the outer skin, for example, but is not limited thereto.

[0053] For example, the cross-sectional area of ​​the hole (2) may be measured by observing with the naked eye or by imaging the external length using various methods, but is not limited thereto.

[0054]

[0055] The above hole (2) may be formed to have a depth of 0.05 mm or more.

[0056] The above hole (2) may be formed to have a depth of 0.1 to 1.5 mm, specifically 0.5 to 1 mm.

[0057] The above hole (2) may penetrate the outer shell of the cylindrical battery (1), but is not limited thereto.

[0058] The above hole (2) can penetrate the cylindrical battery (1), but is not limited thereto.

[0059] In the present invention, “depth of the hole” may mean the vertical distance between an arbitrary line drawn from the bottom of the hole (2) extending in the thickness direction of the cylindrical battery (1) in a direction parallel to the horizontal direction of the cylindrical battery (1) and the surface of the cylindrical battery (1).

[0060]

[0061] In another embodiment of the present invention, the number of gas outlets (2) may be 1 to 40, preferably 2 to 30, and more preferably 2 to 15.

[0062] When the above gas discharge port (2) is formed within the above range, it is preferable that the formation of the above gas discharge port (2) is easy, the process time can be shortened, and the explosion suppression effect of the cylindrical battery is maximized.

[0063]

[0064] In short, in the present invention, the gas discharge port (2) may be a passage through which gas, carbon dioxide, carbon monoxide, etc. generated by vaporization of electrolyte, etc., escape.

[0065]

[0066] The above gas discharge port (2) can be formed using a drill, punch, needle, laser, cutting machine, compression destruction, shear destruction means, etc., but is not limited thereto.

[0067] For example, it can be formed by pressing the outer shell of the cylindrical battery (1) with an awl at one or more locations to make a hole (2).

[0068]

[0069] Steps for heating a cylindrical battery

[0070] A method for recycling a cylindrical battery (1) according to the present invention includes a step of heating the cylindrical battery (1) in which the gas exhaust port (2) is formed.

[0071] The step of heating the above cylindrical battery (1) can be performed using, but is not limited to, inductive heating using an electromagnetic field, resistance heating, indirect heating using gas, etc.

[0072] In another embodiment of the present invention, the step of heating the cylindrical battery (1) can be performed at 700 to 1400°C.

[0073] Preferably, the step of heating the cylindrical battery (1) can be performed at 700 to 1300°C, more preferably at 700 to 1100°C.

[0074] The step of heating the cylindrical battery (1) is preferably performed within the above temperature range because sufficient internal reduction occurs. Furthermore, it is preferable because loss due to lithium vaporization can be suppressed and sintering of alloy elements is excellent. Furthermore, when heated within the above temperature range, the electrolyte within the battery vaporizes, the separator turns to ash, and the reduction reaction reduces the overall volume by approximately 40%. This facilitates the separation of the reactants within the battery and the iron forming the outer shell.

[0075]

[0076] In another embodiment of the present invention, the step of heating the cylindrical battery (1) may be performed for 10 to 100 minutes. Preferably, it may be performed for 10 to 50 minutes, and more preferably, it may be performed for 10 to 30 minutes.

[0077] Specifically, the cylindrical battery (1) can be heated to the above temperature range and then maintained within the above temperature range.

[0078] When the step of heating the cylindrical battery (1) is performed within the above range, it is preferable that the process time can be shortened while the internal reduction reaction can sufficiently occur.

[0079] Specifically, the step of heating the cylindrical battery (1) may be performed at a temperature of the surface of the cylindrical battery (1) of 700°C or higher and 1400°C or lower, which is lower than the melting point of the surface material of the cylindrical battery (1), so that the internal reduction reaction can occur smoothly.

[0080] More specifically, the step of heating the cylindrical battery (1) may be to heat the surface of the cylindrical battery (1) for 10 to 20 minutes so that the temperature value of the surface of the cylindrical battery (1) can be 700 to 800°C so that the internal reduction reaction can occur smoothly, and then to increase the temperature value of the surface to 800 to 1400°C, preferably 1100 to 1400°C, and more preferably 1150 to 1300°C so that sintering is excellent.

[0081]

[0082] The step of heating the cylindrical battery (1) may be a dry heat treatment. In short, the method for recycling a cylindrical battery (1) according to the present invention includes a heat treatment step for performing a high-temperature reduction reaction without going through a melting step.

[0083] In another embodiment of the present invention, the step of heating the cylindrical battery (1) in which the gas outlet (2) is formed can be performed using induction heating.

[0084] By using the above induction heating, the temperature of the outer shell of the cylindrical battery (1) is increased.

[0085] The above induction heating using an electromagnetic field can be performed using a high-frequency generator, and an appropriate induction heating frequency may need to be selected depending on the thickness of the outer shell of the cylindrical battery (1).

[0086] A frequency selection range may be required depending on the thickness of the outer shell and the radius of the cylindrical battery (1).

[0087] For example, the outer shell thickness of the cylindrical battery (1) may be 0.05 to 1 mm, and this may be used to determine the range of maximum frequency.

[0088] In another embodiment of the present invention, the frequency of the induction heating may be 2.5 kHz to 3 MHz. Preferably, the frequency of the induction heating may be 2.5 kHz to 1500 kHz, and more preferably, 2.5 kHz to 600 kHz.

[0089] In short, the frequency of the above induction heating can be appropriately selected depending on the outer shell thickness and radius of the above cylindrical battery (1).

[0090] Specifically, the cylindrical battery (1) may have a diameter of 10 to 25 mm, preferably 15 to 20 mm, and more preferably 18 to 20 mm.

[0091] The range of the lowest frequency of the above induction heating is related to the radius of the cylindrical battery (1), and since it also affects the rise in temperature inside the cylindrical battery (1), it is desirable to satisfy the above range by taking into consideration the internal reaction speed, etc.

[0092]

[0093] The step of heating the cylindrical battery (1) may be performed under an atmosphere of at least one gas selected from the group consisting of an inert gas, carbon dioxide, carbon monoxide, and hydrocarbon gas, but is not limited thereto.

[0094] The above inert gas may include, but is not limited to, one or more selected from the group consisting of argon and nitrogen.

[0095] When the step of heating the cylindrical battery (1) is performed under the gas atmosphere, it is preferable that the valuable metal recovery alloy can be effectively recovered.

[0096]

[0097] The recycling method of a cylindrical battery (1) according to the present invention may have a reduction rate of 70% or more, specifically 80% or more, more specifically 85% or more, and most specifically 90% or more.

[0098]

[0099] Step of crushing cylindrical batteries to obtain shredded material

[0100] A method for recycling a cylindrical battery (1) according to the present invention includes a step of crushing the heated cylindrical battery (1) to obtain crushed material.

[0101]

[0102] In another embodiment of the present invention, the step of crushing the heated cylindrical battery (1) to obtain crushed material may further include a step of cooling the heated cylindrical battery (1) beforehand.

[0103] In the case where a step of cooling the heated cylindrical battery (1) is further included, the crushing process can be performed after suppressing ignition of the liquid electrolyte contained in the cylindrical battery (1), thereby suppressing problems due to ignition of the electrolyte, which is preferable.

[0104] Specifically, since the phenomenon of a spark being generated by physically crushing the separator and forming a high current due to a short circuit as a specific pressure is applied to the cylindrical battery (1) during the crushing process can be suppressed, it is preferable to further include a step of cooling the heated cylindrical battery (1).

[0105]

[0106] In another embodiment of the present invention, the step of crushing the heated cylindrical battery (1) to obtain crushed material may further include a step of cutting a portion of the cylindrical battery (1) beforehand.

[0107] Specifically, the step of cutting a part of the cylindrical battery (1) may be performed between the step of cooling the heated cylindrical battery (1) and the step of crushing the heated cylindrical battery (1) to obtain crushed material.

[0108] More specifically, if the gas outlet (2) is in the form of a hole (2), a step of cutting a part of the cylindrical battery (1) may be further included.

[0109] In the case where the above gas discharge port (2) is in the form of a hole (2), the shredded material can be recovered more easily by further including a step of cutting a part of the cylindrical battery (1).

[0110] The above cooling can be performed at room temperature.

[0111]

[0112] The above crushing may include crushing the cylindrical battery (1) by applying physical or mechanical force and crushing it into fine powder.

[0113] By crushing the above cylindrical battery (1), some large impurities, such as aluminum (Al), copper (Cu), iron (Fe) and plastic, or in short, black powder, can be separated.

[0114] The above-mentioned crushed material is a valuable metal recovery composition alloyed with components such as nickel, cobalt, manganese and lithium-containing oxides, and may contain valuable metals and residual impurities.

[0115] In the present invention, “valuable metal” may refer to an expensive metal component included in a battery. For example, the valuable metal may refer to nickel, copper, manganese, aluminum, copper, and lithium.

[0116] The above-described metal recovery composition may include, but is not limited to, aluminum (Al), manganese (Mn), lithium (Li), copper (Cu), cobalt (Co), nickel (Ni), carbon (C) and residual impurities.

[0117] For example, the black powder may contain 5 to 40 wt% of nickel (Ni), 1 to 20 wt% of cobalt (Co), 1 to 15 wt% of manganese (Mn), 0.5 to 5 wt% of lithium (Li), 10 to 70 wt% of carbon (C), 0.0001 to 20 wt% of aluminum (Al), and 0.0001 to 20 wt% of copper (Cu), and the total of impurities such as iron (Fe) and phosphorus (P) may be less than 10 wt%, but is not limited thereto.

[0118] The components of the above black powder may vary depending on the ratio of nickel, cobalt, and manganese, and the nickel, cobalt, and manganese may be controlled by the positive electrode oxide in the lithium secondary battery when the lithium secondary battery is crushed.

[0119]

[0120] The above crushing may be a crushing method using at least one of shear, compression and tensile force.

[0121] For example, the crushing can be performed using at least one selected from the group consisting of a hammer mill, a ball mill, and a stirred ball mill.

[0122] The above hammer milling may be performed in one or more steps selected from the group consisting of, but not limited to, disintegration, punching and milling, and may be performed using various types of crushing and / or pulverizing devices performed in the art.

[0123] For example, this may be accomplished using a shredder or industrial crusher, but is not limited thereto.

[0124]

[0125] The above-mentioned shredded material may have a particle size of less than 100 mm, specifically less than 30 mm, but is not limited thereto.

[0126] However, if the particle size of the shredded material satisfies the above range, it is preferable for easy recovery in the recovery step described later.

[0127] The above shredded material may be in the form of flakes, but is not limited thereto.

[0128]

[0129] Step of separating the shredded material to obtain recovered material

[0130] The method for recycling a cylindrical battery (1) according to the present invention includes a step of separating the shredded material to obtain a recovered material.

[0131]

[0132] In another embodiment of the present invention, the step of separating the crushed material to obtain a recovered material may be performed by one or more separation methods selected from the group consisting of particle size separation, magnetic separation, and specific gravity difference separation.

[0133] Specifically, the above-mentioned crushed material, for example, a valuable metal recovery alloy, can be separated by at least one of particle size separation, magnetic separation, and specific gravity difference separation.

[0134] The above particle size separation method is a method of separating particles according to their size or diameter, and may include, but is not limited to, various methods of separation using a sieve, for example.

[0135] The above magnetic separation method utilizes a magnetic substance, and particles can be separated through contact with the magnetic substance. Various types of magnetic separation methods can be applied, but are not limited thereto.

[0136] The above-mentioned specific gravity separation is a method of separating particles by considering the difference in specific gravity of each substance. For example, by using a specific solvent, particles can be separated based on the size of the specific gravity of the particles corresponding to the specific solvent. Various types of specific gravity separation methods can be applied.

[0137]

[0138] The iron contained in the outer shell of the above cylindrical battery (1) can be removed by separating the above shredded material.

[0139] Specifically, the iron can be removed by using a method of recovering the shredded material and recovering the remaining iron.

[0140] Removing the above iron is desirable because it minimizes the load on the subsequent wet process and drastically reduces the amount of hydrochloric acid that must be used in the wet process.

[0141]

[0142] In another embodiment of the present invention, the step of separating the crushed material to obtain a recovered material may be performed by first performing the magnetic separation and then performing the particle size separation.

[0143] By prioritizing the magnetic separation, it is preferable to suppress the loss of valuable metal recovery alloy from fragments of 100 μm or less.

[0144] In another embodiment of the present invention, the step of separating the crushed material to obtain a recovered material may include all of the steps of performing the particle size separation, the magnetic separation, and the particle size separation and the magnetic separation together.

[0145] The step of performing only the above particle size separation can recover a valuable metal recovery alloy only by particle size separation of the composition for recovering valuable metals having a particle size of 100 ㎛ to 100 nm or less of the crushed material.

[0146] In the case of the magnetic separation, if the crushed material contains a material having a particle size of 100 μm or less, the valuable metal can be recovered from the crushed material only by the magnetic separation.

[0147] In the case of the material of 100㎛ or less, since the particle size is similar to that of carbon, the recovery rate of valuable metals lost through particle size separation alone can be increased through the magnetic separation.

[0148]

[0149] The step of separating the above-mentioned crushed material to obtain a recovered material may further include a step of separating the lithium compound containing lithium.

[0150] Specifically, the step of obtaining a recovered product by separating the crushed material using at least one separation method selected from the group consisting of particle size separation, magnetic separation, and specific gravity separation may further include a step of separating the material from a lithium compound containing lithium.

[0151] The step of separating the lithium compound containing lithium may be performed before or after the step of separating the crushed material using one or more separation methods selected from the group consisting of particle size separation, magnetic separation, and specific gravity separation.

[0152] The lithium compound can be bonded to a portion of the surface of the valuable metal recovery alloy. The lithium compound bonded to a portion of the surface of the valuable metal recovery alloy can be separated by an external force.

[0153] The lithium compound may be, for example, a lithium-containing oxide, and may be separated by, but is not limited to, a physical external force, and may be separated using a conventional method performed in the art.

[0154] By separating the above lithium-containing oxide by a physical external force, the recovery rate of lithium as well as valuable metals can be increased.

[0155]

[0156] In another embodiment of the present invention, the recovered material may include a valuable metal.

[0157] In short, the method for recycling a cylindrical battery (1) according to the present invention may relate to a method for recovering valuable metals from a waste cylindrical battery (1).

[0158]

[0159] In another embodiment of the present invention, the valuable metal may include at least one selected from the group consisting of nickel, cobalt, manganese, and copper.

[0160] Specifically, the recovered material may include a valuable metal alloy, and the valuable metal alloy may include at least one selected from the group consisting of nickel, cobalt, manganese, and copper.

[0161] In another embodiment of the present invention, the valuable metal may include nickel, cobalt, manganese and copper.

[0162] Specifically, the above metal alloy may include nickel, cobalt, manganese and copper.

[0163] In another embodiment of the present invention, the valuable metal may include at least one selected from the group consisting of carbon, copper, lithium-aluminum-oxygen alloy, lithium-fluorine alloy, and lithium-carbon-oxygen alloy.

[0164]

[0165] In another embodiment of the present invention, the magnetic metal may be 40 parts by weight or more based on 100 parts by weight of the total metal.

[0166] Specifically, the magnetic valuable metal may be 45 parts by weight or more for 100 parts by weight of the total recovered valuable metal.

[0167] In the method for recycling a cylindrical battery (1) according to the present invention, since the cylindrical battery (1) is directly subjected to a high-temperature reaction, the proportion of nickel, cobalt, manganese, and copper alloys is in the range of 25 to 70% of the total weight, and a lithium compound may be applied to the surface of the alloy together. When magnetic separation (magnetic separation) is performed, nickel, cobalt, manganese, and copper alloys and lithium compounds are mainly produced, and some carbon may be included therein. The weight ratio of the three substances magnetically separated is in the range of 50 to 70% of the total, and specifically, may be 50 to 60%.

[0168] Here, the lithium compound is attached to the surface of the alloy, so that it is separated together when magnetically separated, but can be separated from the alloy by a physical external force. Nickel, cobalt, manganese, and copper alloys may contain carbon in an amount of 0.1 to 7 wt% or less.

[0169] This is because, in the conventional reduction reaction, gas is discharged through the gas outlet (2) of the cylindrical battery (1), so that contact with oxygen can be limited, and as a result, oxygen in the atmosphere cannot burn the carbon of the alloy, so that the carbon content in the alloy appears high.

[0170] In magnetic separation, the weight ratio of the non-magnetic material is in the range of 25 to 40%, and specifically, may be in the range of 25 to 35%. The non-magnetic material mainly consists of a lithium compound and carbon, and may include some nickel, cobalt, manganese, and copper. Here, in an alloy of nickel, cobalt, manganese, and copper, copper may account for 50 wt% or more. In the non-magnetic material, the carbon is mostly about 50 μm or less in size, and specifically, may be 35 μm or less. The lithium compound may have a size of 50 μm or more, and specifically, may have a size of 75 μm or more.

[0171]

[0172] The method for recycling a cylindrical battery (1) according to the present invention forms a gas exhaust port (2) in the outer shell of the cylindrical battery (1), and then increases the temperature to reduce and recover the valuable metal of the cathode material inside the cylindrical battery (1), thereby having the advantage of being able to recycle the cylindrical battery (1) without having to disassemble it through a complicated process as in the past. In addition, there is the advantage of being able to suppress the explosion of the cylindrical battery (1) during the process, and increasing the recovery rate, specifically the recovery rate of the valuable metal.

[0173]

[0174] Hereinafter, preferred embodiments and comparative examples of the present invention are described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

[0175]

[0176] Experimental example

[0177] An 18650 cylindrical battery (diameter 18 mm, height 65 mm) was prepared. Two holes with a diameter of 0.5 mm were drilled into the outer shell using an awl.

[0178] Afterwards, the battery was inductively heated at 700°C for 10 minutes, heated to 1300°C, cooled by air cooling, and then the upper part of the battery was cut and crushed to obtain a powder-like crushed material (see Fig. 3).

[0179] At this time, the frequency used was 2.5 kHz.

[0180] Table 1 below shows the results of the minimum and maximum frequency tests according to the outer skin thickness of a cylindrical flat battery when induction heating is performed.

[0181] The test was conducted by changing the frequency using a pipe made of iron containing more than 70% Fe and performing a temperature increase test according to the thickness of the pipe. In the case of a thick pipe, if the frequency was too high, only the surface was heated and the surface melted, making it difficult to control the temperature. In the case of a thin pipe, if the frequency was too low, there were cases where heating was not done well. It was confirmed that the lowest value according to the thickness was good for heating from 2.5 kHz, and it was confirmed that the temperature increase speed increased when the frequency was increased as the thickness became thinner. In the case of a thick pipe, if the frequency was too high, the surface melted. As a result of the test, it was determined that the frequency of 2.5 kHz was suitable, so this was selected for induction heating.

[0182]

[0183] Outer thickness (mm)Minimum (kHz)Maximum (kHz)12.51500.52.56000.22.530000.12.530000.052.53000

[0184]

[0185] Afterwards, the crushed material was separated by particle size and magnetic separation to finally recover the recovered material. Here, the recovery rate was calculated by heating at 1350℃ for approximately 30 minutes and was found to be approximately 80% of the initial weight of the battery. It is believed that 20% was converted into carbon dioxide and carbon monoxide by vaporizing the electrolyte and reducing the oxide of the cathode material, and then gasified and escaped into the atmosphere.

[0186] The reduction rate of nickel and cobalt was evaluated according to reaction time. The reduction rate was calculated using the weight of the magnetically separated sample after heating at 1350°C for 60 minutes as a standard value. When heated for only 10 minutes, the heat did not penetrate the battery interior, so the cathode material remained charred and unresponsive to magnetism.

[0187] Figure 4 shows the recovered product obtained by magnetically separating the shredded material of Figure 3. A nickel-cobalt-copper-manganese alloy component in a circular or oval shape can be observed, and as a result of measuring the component using an electron microscope, it can be seen that the outside of the alloy is coated with a lithium compound.

[0188] The magnetically separated sample was approximately 70% of the standard value, and after 15 minutes of reaction, it was separated by magnetic force by approximately 90% or more, and after 20 minutes, it showed an equivalent level of 98-100%. It is believed that the 98% or more is due to an error that appears during the recovery process. Figure 2 shows data showing the reduction rate according to the heating time of a cylindrical battery when using an 18650 battery at a temperature of 700℃.

[0189]

[0190] The present invention is not limited to the above-described embodiments, but can be manufactured in a variety of different forms. Those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

[0191]

[0192] [Explanation of symbols]

[0193] 1: Cylindrical battery

[0194] 2: Gas exhaust port

Claims

1. Step for preparing a cylindrical battery; A step of forming at least one gas outlet on the surface of the cylindrical battery; A step of heating the cylindrical battery in which the gas outlet is formed; A step of crushing the heated cylindrical battery to obtain crushed material; and A step of separating the above crushed material to obtain a recovered material; including, How to recycle cylindrical batteries.

2. In paragraph 1, The step of forming the above gas outlet is: A method for recycling a cylindrical battery, comprising the step of forming at least one hole on the surface of the cylindrical battery.

3. In paragraph 1, The step of forming the above gas outlet is: A method for recycling a cylindrical battery, comprising the step of cutting a portion of the cylindrical battery.

4. In paragraph 2, A method for recycling a cylindrical battery, further comprising: a step of crushing the heated cylindrical battery to obtain shredded material; and a step of cutting a portion of the cylindrical battery beforehand.

5. In paragraph 2, In the step of forming the above hole, the hole has a cross-sectional area of ​​0.01 mm 2 A method for recycling a cylindrical battery formed to be ideal.

6. In paragraph 5, The above hole has a cross-sectional area of ​​0.2 to 10 mm. 2 A method for recycling a cylindrical battery formed to be like this.

7. In paragraph 2, A method for recycling a cylindrical battery, wherein the hole is formed to penetrate the outer shell of the cylindrical battery.

8. In paragraph 1, A method for recycling a cylindrical battery, wherein the outer shell of the cylindrical battery has a thickness of 0.05 to 1 mm, and the outer shell includes an alloy having an Fe content of 60 at% or more.

9. In paragraph 1, A method for recycling a cylindrical battery, wherein the step of heating the cylindrical battery is performed at 700 to 1400°C.

10. In paragraph 1, A method for recycling a cylindrical battery, wherein the step of heating the cylindrical battery in which the gas exhaust port is formed is performed using induction heating.

11. In paragraph 10, A method for recycling a cylindrical battery, wherein the frequency of the above induction heating is 2.5 kHz to 3 MHz.

12. In paragraph 1, A method for recycling a cylindrical battery, wherein the step of heating the cylindrical battery is performed for 10 to 100 minutes.

13. In paragraph 1, A step of crushing the heated cylindrical battery to obtain shredded material; previously, A method for recycling a cylindrical battery, further comprising the step of cooling the heated cylindrical battery.

14. In paragraph 1, A method for recycling a cylindrical battery, wherein the step of separating the above-mentioned shredded material to obtain a recovered material is performed by at least one separation method selected from the group consisting of particle size separation, magnetic separation, and specific gravity difference separation.

15. In paragraph 14, A method for recycling a cylindrical battery, wherein the step of separating the above-mentioned shredded material to obtain a recovered material is performed by first performing the magnetic separation and then performing the particle size separation.

16. In paragraph 1, A method for recycling a cylindrical battery, wherein the recovered material contains valuable metal.

17. In paragraph 16, A method for recycling a cylindrical battery, wherein the above valuable metal comprises at least one selected from the group consisting of nickel, cobalt, manganese and copper.

18. In paragraph 17, A method for recycling a cylindrical battery, wherein the above valuable metals include nickel, cobalt, manganese and copper.

19. In paragraph 18, A method for recycling a cylindrical battery, wherein the above-mentioned valuable metal comprises at least one selected from the group consisting of carbon, copper, lithium-aluminum-oxygen alloy, lithium-fluorine alloy, and lithium-carbon-oxygen alloy.

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