Lithium carbonate recycling system from waste lithium-ion batteries, method for recycling lithium carbonate using same, and high-purity lithium carbonate crystals recycled using same

Abstract

The present invention relates to a recycling method for recovering and recycling battery-grade lithium carbonate (Li2CO3) from waste lithium-ion batteries, and to a system applying same. Recycled lithium carbonate crystals of the present invention have a very high proportion of plate-shaped crystals while having high purity, and thus, battery-grade recycled lithium carbonate can be produced and provided with high economic efficiency.

Description

A lithium carbonate recycling system from waste lithium-ion batteries, a method for recycling lithium carbonate using the same, and high-purity lithium carbonate crystals recycled using the same

[0001] The present invention relates to a recycling method for recovering and recycling lithium carbonate (Li2CO3) from lithium-ion battery waste, and a system applied thereto. The recycled lithium carbonate crystals of the present invention have a higher purity than battery-grade lithium carbonate mined from existing mines, and a higher proportion of plate-shaped crystals than lithium carbonate obtained from battery recycling, and thus can exhibit characteristics of functions equivalent to or superior to those of a lithium-ion secondary battery manufactured with recycled lithium carbonate, such as charging capacity, efficiency, and lifespan, compared to existing battery-grade lithium carbonate.

[0002] Lithium-ion secondary batteries (batteries) are used not only in portable IT devices like mobile phones and laptops, but also in various fields such as electric vehicles and energy storage systems (ESS), and their market is continuously expanding. Lithium, a key raw material used in lithium-ion batteries, is a strategic metal resource, with global reserves estimated at approximately 13 million tons. Lithium resources are concentrated in a few countries, making competition for its acquisition fierce. It is a metal with both economic viability and scarcity.

[0003] As the use of lithium-ion batteries expands, the disposal of used lithium-ion batteries is becoming a problem, and research is actively being conducted on ways to recover and recycle lithium or valuable metals that are discarded as waste.

[0004] The annual processing capacity of the metal recovery process of a major domestic waste lithium-ion battery recycling company is estimated to be approximately 12,000 tons / year, and when the process is fully operational, approximately 12,000 tons of manganese sulfate waste liquid and 180,000 tons of lithium sulfate waste liquid will be generated. As the use of domestic waste lithium-ion batteries increases, the metal recovery process is expected to be expanded in the future, and the amount of waste liquid generated is also expected to increase.

[0005] Furthermore, existing lithium-ion battery recycling processes suffer from the inconvenience of having to separate batteries by type and shape. Furthermore, they use hazardous chemicals like sulfuric and hydrochloric acid, making them difficult to handle and not environmentally friendly. Furthermore, they require a separate process for discharging, and even when claimed as non-dischargeable, they present ongoing risks and are unstable.

[0006] In addition, since the recycling process efficiency is low and the operating cost is high, even if lithium-ion batteries are recycled, the situation is no different from the existing mining process. Furthermore, battery-grade lithium carbonate must guarantee not only quality but also performance when used in batteries, but lithium carbonate made through the existing recycling process has limitations in that its performance is low when applied to secondary batteries.

[0007] (Prior art literature)

[0008] (Patent Document)

[0009] (Patent Document 1) Korean Patent No. 10-1604954 (Announcement Date: March 18, 2016)

[0010] (Patent Document 2) Korean Patent Publication No. 10-2023-0136948 (Published on October 4, 2023)

[0011] (Patent Document 3) Korean Patent Publication No. 10-2021-0138922 (Published on November 22, 2021)

[0012] The present invention aims to provide a method and system capable of recovering lithium carbonate with high purity in an environmentally friendly manner through an integrated recycling process that does not distinguish between the raw material forms of waste lithium-ion batteries, and at this time, the recycled lithium carbonate has a very high proportion of plate-shaped crystals, thereby providing recycled lithium carbonate having lithium-ion battery-grade quality.

[0013] The lithium carbonate recycling system of the present invention for solving the above problems comprises: an input unit for inputting lithium-ion battery waste; a passivation unit for passivating lithium-ion battery waste; a crushing unit for crushing passivated lithium-ion battery waste; a decomposition unit for decomposing binder, electrolyte and additives contained in the crushed material to obtain stabilized crushed material and recovering at least one selected from among decomposed organic solvents, electrolyte salts and additives; a heat treatment unit for heat-treating the stabilized crushed material to obtain heat-treated crushed material; a classification unit for separating and sorting the heat-treated crushed material to separate battery black mass containing Li2CO3 and other crushed material; a water leaching unit for inputting and reacting the black mass obtained from the classification unit into a water leaching reactor to convert Li2CO3 in the black mass to LiHCO3, dissolving LiHCO3 in water, and performing a process of removing fluorine (F) from an aqueous solution containing LiHCO3; It includes a solid-liquid separation unit for removing waste scrap and impurities from an aqueous solution containing LiHCO3 from which fluorine has been removed in a water leaching unit to obtain a LiHCO3 aqueous solution; a crystallization unit for treating the LiHCO3 aqueous solution obtained through the solid-liquid separation treatment with microwaves to crystallize LiHCO3 into Li2CO3; and a dehydration / washing unit for dehydrating and washing the crystallized Li2CO3-containing solution to obtain Li2CO3 crystals.

[0014] As a preferred embodiment of the present invention, the lithium carbonate recycling system of the present invention can re-inject a solution containing at least one selected from among the dehydration solution and the washing solution generated in the dehydration / washing unit into the water leaching unit.

[0015] In a preferred embodiment of the present invention, the lithium ion battery waste includes at least one selected from black mass, process scrap, battery cells, battery modules, and battery packs, and each of the black mass, process scrap, battery cells, battery modules, and battery packs contains lithium.

[0016] As a preferred embodiment of the present invention, each of the passivation unit, crushing unit, decomposition unit and heat treatment unit independently has an N2 and CO2 or mixed gas injection unit, or has an N2 injection unit and a CO2 injection unit separately.

[0017] As a preferred embodiment of the present invention, the CO2 injected into each of the passivation section, crushing section, decomposition section, and heat treatment section may independently be supercritical CO2 or gaseous CO2.

[0018] As a preferred embodiment of the present invention, N2 injected into each of the passivation section, crushing section, decomposition section, and heat treatment section may be injected at -70 to -50°C, and when CO2 is supercritical CO2, CO2 may be injected at 30 to 80°C, and when CO2 is gaseous, CO2 may be injected at -70 to -90°C.

[0019] In a preferred embodiment of the present invention, each of the N2 and CO2 does not contain moisture.

[0020] As a preferred embodiment of the present invention, the input unit of the lithium carbonate recycling system of the present invention may be configured as a sealed conveyor, and the drying treatment unit may be configured as a box-type cooling device equipped with a conveyor, a rotary kiln-type cooling device, or a screw-type cooling device.

[0021] As a preferred embodiment of the present invention, each of the passivation treatment and the crushing treatment is performed in an atmosphere containing O25% by volume or less and CO2 and N2 with the remaining balance of 100% by volume, and the CO2 and N2 may be included in a volume ratio of 1:3.8 to 4.4.

[0022] As a preferred embodiment of the present invention, the crushing unit may additionally include a stabilizing mixing unit that decomposes and stabilizes the electrolyte passivated by supercritical CO2 or gaseous CO2.

[0023] In a preferred embodiment of the present invention, the decomposition unit comprises a supercritical CO2 maintenance unit; a CO2 capture unit that captures gas-phase treated CO2; a cooling unit that separates a cooled solution from the gas-phase treated CO2; and a CO2 recapture transport unit that recaptures the gas-phase CO2 from which the cooled solution has been separated and transports it to a water leaching unit; and the CO2 capture unit may include a cooling unit and a solution collection unit that collects the cooled solution from the gas-phase treated CO2.

[0024] As a preferred embodiment of the present invention, the heat treatment unit of the lithium carbonate recycling system of the present invention is equipped with a box-type heat treatment furnace, a tunnel-type heat treatment furnace, a vertical heat treatment furnace, a vertical rotary heat treatment furnace, or a rotary kiln-type heat treatment furnace.

[0025] In a preferred embodiment of the present invention, the heat treatment is performed under an oxygen-free atmosphere, and the heat treatment is performed under a mixed gas of 10 to 30 volume% of the carbon precursor and the remaining balance of 100 volume%, wherein the mixed gas is H2, CO2 and N2 can be included in a molar ratio of 0.02 to 0.06: 0.15 to 0.35: 0.41 to 0.87.

[0026] As a preferred embodiment of the present invention, the CO2 injected during the heat treatment may be CO2 injected in the passivation section, crushing section, and / or decomposition section, collected, and reinjected into the heat treatment section.

[0027] As a preferred embodiment of the present invention, the classification unit of the lithium carbonate recycling system of the present invention includes an air classification unit, a particle size separation classification unit, and a magnetic separation unit.

[0028] As a preferred embodiment of the present invention, the air classification unit is composed of a single or multiple air classification units.

[0029] As a preferred embodiment of the present invention, the particle size separation classifying unit is equipped with a plurality of plate-shaped or circular vibrating screens and a plurality of ultrasonic devices.

[0030] As a preferred embodiment of the present invention, the magnetic separation unit is equipped with a device for performing a process of magnetically separating and separating reduced materials in black mass obtained from the particle size separation classifier.

[0031] As a preferred embodiment of the present invention, the water leaching unit of the lithium carbonate recycling system of the present invention comprises a cylindrical water leaching reactor or a stirred water leaching reactor, balls for a ball mill in the water leaching reactor, a CO2 injection unit, a fluorine removing agent and impurity removing agent injection unit, and a pressure reducing device.

[0032] As a preferred embodiment of the present invention, the fluoride remover and impurity remover input units may be configured as one input unit or separate input units.

[0033] As a preferred embodiment of the present invention, the lithium carbonate recycling system of the present invention may further include a drying unit for drying Li2CO3 crystals.

[0034]

[0035] Another object of the present invention is to provide a method for recycling lithium carbonate from waste lithium ion batteries, wherein Li2CO3 is recovered at a high purity from waste lithium ion batteries using the lithium carbonate recycling system described above.

[0036] In a preferred embodiment of the present invention, a method for recycling lithium carbonate from spent lithium ion batteries comprises: a first step of passivating lithium ion battery waste; a second step of crushing the passivated lithium ion battery waste to produce crushed materials having a particle size of 0.1 to 15 cm; a third step of decomposing electrolyte, binder, and additives contained in the crushed lithium ion battery waste and recovering the decomposed materials, thereby obtaining stabilized crushed materials; a fourth step of heat-treating the stabilized crushed materials of the third step to obtain heat-treated crushed materials containing lithium oxide and lithium fluoride; a fifth step of separating and sorting the heat-treated crushed materials to obtain battery black mass containing Li2CO3; a sixth step of introducing the battery black mass into a water leaching reactor and subjecting it to a water leaching reaction to convert Li2CO3 in the black mass into LiHCO3, thereby producing an aqueous solution containing LiHCO3 dissolved in water; A process is performed including: a 7-step process for removing fluorine (F) and impurities from an aqueous solution containing LiHCO3 to produce an aqueous solution containing LiHCO3 from which fluorine has been removed; an 8-step process for performing a solid-liquid separation process on the aqueous solution containing LiHCO3 from which fluorine has been removed to obtain a LiHCO3 aqueous solution from which waste scrap and impurities have been removed; a 9-step process for performing a microwave treatment on the LiHCO3 aqueous solution obtained through the solid-liquid separation process to crystallize LiHCO3 into Li2CO3 to produce a crystallized Li2CO3-containing solution; and a 10-step process for performing a dehydration process and a washing process on the crystallized Li2CO3-containing solution to obtain Li2CO3 crystals.

[0037] In a preferred embodiment of the present invention, at least one selected from among the dehydrated dehydration liquid and the washed washing liquid generated in step 10 can be recycled in step 6.

[0038] In a preferred embodiment of the present invention, each of the passivation treatment in step 1, the crushing treatment in step 2, the decomposition treatment in step 3, and the heat treatment in step 4 is performed under a gas atmosphere containing N2 and CO2.

[0039] As a preferred embodiment of the present invention, the first step passivation treatment and the second step crushing treatment are performed using oxygen (O2). It can be performed under an atmosphere containing CO2 and N2 with a balance of 5% by volume or less and 100% by volume or less.

[0040] As a preferred embodiment of the present invention, the three-step decomposition treatment is performed under conditions in which the injected supercritical CO2 maintains a supercritical state.

[0041] In a preferred embodiment of the present invention, the four-step heat treatment is performed under a mixed gas of 1 to 20 volume% of carbon precursor and the remaining balance of 100 volume%, wherein the mixed gas comprises H2, CO2 and It contains N2 in a molar ratio of 0.02 to 0.06: 0.15 to 0.35: 0.41 to 0.87 and is performed under an oxygen-free atmosphere.

[0042] In a preferred embodiment of the present invention, the four-step heat treatment is performed at 200 to 1,150°C for 30 to 360 minutes.

[0043] As a preferred embodiment of the present invention, the four-step heat treatment may be performed at 600 to 1,150°C for 30 to 360 minutes.

[0044] As a preferred embodiment of the present invention, the heat treatment may be performed at a temperature of 600 to 800°C when the shredded material is a shredded material derived from an NCM (lithium nickel manganese) battery, an NCA (ternary lithium) battery, or an LCO (lithium cobalt oxide) battery.

[0045] As a preferred embodiment of the present invention, the heat treatment may be performed at a temperature of 850 to 1150°C when the shredded material is a shredded material derived from an LMO (lithium manganese nickel oxide) battery or an LFP (lithium iron phosphate) battery.

[0046] As a preferred embodiment of the present invention, the heat treatment may be performed stepwise at a temperature of 200 to 1150°C when the shredded material is a mixed or individual battery of an NCM (lithium nickel manganese) battery, an NCA (ternary lithium) battery, an LCO (lithium cobalt oxide) battery, an LMO (lithium manganese nickel oxide) battery, or an LFP (lithium iron phosphate) battery.

[0047] As a preferred embodiment of the present invention, the separation and selection treatment of the heat-treated crushed material in the 5-step process may include a step 5-1 of subjecting the heat-treated crushed material to an air classification treatment to obtain a crushed material from which crushed material lighter than black mass has been removed; a step 5-2 of subjecting the crushed material obtained through step 5-1 to a particle size separation treatment to obtain black mass from which crushed material heavier than black mass has been removed; and a step 5-3 of subjecting the black mass obtained through step 5-2 to a magnetic selection treatment to obtain black mass containing Li2CO3 from which reduced substances in the black mass have been removed.

[0048] In a preferred embodiment of the present invention, the heavy crushed material of step 5-2 contains at least one metal selected from Co, Ni, Mn, Al, Cu and Fe.

[0049] As a preferred embodiment of the present invention, in step 6, water, balls for a ball mill, and black mass containing Li2CO3 obtained in step 5 are introduced into a water leaching reactor, and then CO2 is introduced while performing a water leaching reaction under conditions of a rotation speed of the water leaching reactor or a stirrer rotation speed of 50 to 400 rpm and a temperature of 10 to 50°C for 30 minutes to 5 hours.

[0050] Step 6 can be done by adding black mass containing water and Li2CO3 in a weight ratio of 1:1 to 10.

[0051] As a preferred embodiment of the present invention, the six-step water leaching reaction can be performed under conditions in which a pH of 5 to 7 is maintained.

[0052] As a preferred embodiment of the present invention, the step 7 may be performed for 30 minutes to 2 hours by adding a fluoride removing agent and an impurity removing agent to a leaching reactor containing an aqueous solution containing LiHCO3 after 30 minutes have passed since the completion of the leaching reaction, and then at a rotation speed of the leaching reactor or a stirrer rotation speed of 50 to 400 rpm and a temperature of 10 to 50°C.

[0053] As a preferred embodiment of the present invention, the fluoride remover may include at least one selected from Ca(OH)2, CaO, K(OH)2, and K2O.

[0054] As a preferred embodiment of the present invention, the impurity removing agent may include Na2CO3.

[0055] As a preferred embodiment of the present invention, the 9-step microwave treatment is performed under a vacuum atmosphere and at 40 to 70°C, and can be performed while irradiating the LiHCO3 aqueous solution with microwaves of 600 to 1200 W and stirring at a stirring speed of 100 to 400 rpm.

[0056] As a preferred embodiment of the present invention, the 10-step Li2CO3 crystals may comprise 50 wt% or more of plate-shaped crystals.

[0057]

[0058] Another object of the present invention is to provide recycled lithium carbonate (Li2CO3) crystals obtained through the system and method described above.

[0059] As a preferred embodiment of the present invention, the lithium carbonate (Li2CO3) crystal has a purity of 99.00 to 99.99% and contains plate-shaped crystals in an amount of 50 wt% or more.

[0060] In addition, an object of the present invention is to provide a cathode material for a lithium ion secondary battery including the recycled lithium carbonate crystals.

[0061] In addition, an object of the present invention is to provide a lithium ion secondary battery including the recycled lithium carbonate crystals.

[0062]

[0063] The term "black mass" used in the present invention hereinafter includes black powder unless specifically stated otherwise.

[0064] The present invention relates to a system and method for recycling lithium carbonate from waste lithium-ion batteries, which are environmentally friendly and highly efficient, and which can process waste batteries regardless of their type. The recycled lithium carbonate crystals produced by the system and method can provide high-purity, battery-grade lithium carbonate crystals with a very high content of plate-like crystals and a very low content of impurities.

[0065] Figure 1 is a schematic diagram of a system for recycling lithium carbonate from spent lithium-ion batteries.

[0066] Figure 2, A, is an example showing an example of air classification, and Figure 2, B, is an example showing an example of a particle size separation classifier equipped with a vibrating screen.

[0067] Hereinafter, the present invention will be described in more detail.

[0068] The method of recycling lithium carbonate from a spent lithium ion battery of the present invention is a method of recycling lithium carbonate using a system including an input unit; a passivation unit; a crushing unit; a decomposition unit; a heat treatment unit; a classification unit; a water leaching unit; a solid-liquid separation unit; a crystallization unit; and a dehydration / washing unit, as schematically shown in FIG. 1.

[0069] More specifically, the method for recycling lithium carbonate from spent lithium-ion batteries comprises the following steps: 1) passivating lithium-ion battery waste; 2) crushing the passivated lithium-ion battery waste; 3) decomposing electrolyte, binder and additives contained in the crushed lithium-ion battery waste and recovering the decomposed materials, thereby obtaining stabilized crushed waste; 4) heat-treating the stabilized crushed waste to obtain heat-treated crushed waste containing lithium oxide and lithium fluoride; 5) separating and sorting the heat-treated crushed waste to obtain battery black mass containing Li2CO3; 6) introducing the battery black mass into a water leaching reactor and subjecting it to a water leaching reaction to convert Li2CO3 in the black mass into LiHCO3, thereby producing an aqueous solution containing LiHCO3 dissolved in water; A process is performed including: a 7-step process for removing fluorine (F) from an aqueous solution containing LiHCO3 to produce an aqueous solution containing LiHCO3 from which fluorine has been removed; an 8-step process for performing a solid-liquid separation process on the aqueous solution containing LiHCO3 from which fluorine has been removed to obtain a LiHCO3 aqueous solution from which waste scrap and impurities have been removed; a 9-step process for performing a microwave treatment on the LiHCO3 aqueous solution obtained through the solid-liquid separation process to crystallize LiHCO3 into Li2CO3 to produce a crystallized Li2CO3-containing solution; and a 10-step process for performing a dehydration process and a washing process on the crystallized Li2CO3-containing solution to obtain Li2CO3 crystals.

[0070]

[0071] The first step of passivation treatment is a process to prevent explosion or fire in undischarged batteries and / or batteries with residual energy remaining after discharge, and passivates lithium-ion battery waste fed from the input port.

[0072] The lithium-ion battery waste inputted into the above input unit is waste containing lithium, and includes at least one selected from black mass, process scrap, battery cells, battery modules, and battery packs.

[0073] In addition, the lithium-ion battery waste may be battery waste including at least one selected from among NCM (lithium nickel manganese) batteries, NCA (ternary lithium) batteries, LCO (lithium cobalt oxide) batteries, LMO (lithium manganese nickel oxide) batteries, LFP (lithium iron phosphate) batteries, and all-solid-state batteries (ASB).

[0074] Additionally, the above-mentioned input section may be configured as a sealed conveyor.

[0075] In addition, the passivation unit is configured as a sealed cooling device for maintaining low temperature and increasing the reaction area and for rapid passivation, and may be configured as a box-type cooling device equipped with a conveyor, a rotary kiln-type cooling device, or a screw-type cooling device, and may preferably be configured as a box-type cooling device equipped with a conveyor including a cooling plate.

[0076] And, the passivation part contains N2 and CO2. A mixed gas inlet may be provided, or an N2 inlet and a CO2 inlet may be provided separately.

[0077] And, the N2 and CO2 that are injected do not contain moisture, and the temperature of the N2 injected or mixed into the mixed gas is -70 to -50°C, preferably -65 to -55°C, and the temperature of the CO2 injected individually or mixed into the mixed gas is -30 to -90°C, preferably -40 to -70°C.

[0078] And, the passivation treatment performed in the passivation section is oxygen (O2). It is performed under an atmosphere containing CO2 and N2 of 5% by volume or less and the remaining amount of 100% by volume, and by simultaneously controlling low temperature, oxygen concentration and moisture, the waste is stabilized to prevent fire and explosion, and lithium loss is prevented. At this time, in the passivation section, CO2 and N2 can be included in a volume ratio of 1:3.8 to 4.4, preferably in a volume ratio of 1:3.9 to 4.2, and if the N2 volume ratio is less than 3.8, the passivation state may be difficult, and if the N2 volume ratio exceeds 4.4, there may be a problem that the decomposition rate of the electrolyte and binder in the decomposition section is low.

[0079] And, by controlling the input ratio of N2 and CO2 having the above temperature, the internal temperature of the cooling device of the passivation part or the passivation treatment temperature can be created and maintained at -70 to -30°C.

[0080]

[0081] Next, the second stage of shredding treatment is a process of crushing lithium-ion battery waste that has been passivated in the passivation unit into particles with a particle size of approximately 0.1 to 15 cm to homogenize the waste and expand the reaction area.

[0082] Since the above crushing treatment is performed under the same conditions as the passivation treatment, the crushing unit may also be equipped with a mixed gas inlet of N2 and CO2 like the passivation unit, or may be equipped with a separate N2 inlet and a CO2 inlet. In addition, the N2 and CO2 that are injected do not each contain moisture, and the temperature of the N2 injected or mixed into the mixed gas is -70 to -50°C, preferably -65 to -55°C, and the temperature of the CO2 injected individually or mixed into the mixed gas is -30 to -90°C, preferably -40 to -70°C.

[0083] In addition, the crushing treatment performed in the crushing unit is oxygen (O2). It is performed under an atmosphere containing CO2 and N2 of 5% by volume or less and the remaining balance of 100% by volume. At this time, the CO2 and N2 may be included in a volume ratio of 1:3.8 to 4.4, preferably 1:3.9 to 4.2, and if the N2 volume ratio is less than 3.8, it may be difficult to maintain the passivation state of the crushed material, and if the N2 volume ratio exceeds 4.4, there may be a problem of the electrolyte and binder decomposition rate being lowered in the decomposition section.

[0084] And, by controlling the input ratio of N2 and CO2 having the above temperature, the temperature inside the cooling device of the crushing unit or the crushing treatment temperature can be created and maintained at -70 to -30°C.

[0085] In addition, the shredding process is also performed in a closed state, and the shredding unit is configured as a closed shredder, and the closed shredder may be equipped with a two-axis shredder, a four-axis shredder, or a double shredder.

[0086] In addition, the crushing process can be performed by spraying deionized water in the form of a mist, if necessary, and the enclosed crusher may be equipped with a mist sprayer. In this case, the deionized water may contain a fire extinguishing agent, a low-conductivity coolant, an ester-based coolant, etc., and the enclosed crusher may be equipped with a separate fire extinguishing agent inlet.

[0087] Additionally, ultrasound can be used as a method to remove unreacted residual charges, and since it can be quickly discharged without mechanical damage, it can be included separately.

[0088]

[0089] Next, the process of obtaining a stabilized shredded product in the third step (decomposition treatment) is to transport the shredded product in the second step to a decomposition unit, and then in the decomposition unit, the electrolyte, binder and / or additives in the lithium-ion battery shredded product are dissolved and decomposed in supercritical CO2 to separate the electrolyte, binder and / or additives from the shredded product, thereby obtaining a stabilized shredded product.

[0090] In addition, it is a process for recovering carbonates and organic acid salts (ethylene carbonate, diethyl carbonate, dimethyl carbonate, propylene carbonate, etc.), lithium salts (hexafluorophosphate, lithium tetrafluoroborate), organic solvents (methyl ethyl carbonate, ethyl metal carbonate, etc.), and additives (fluoroethylene carbonate, vinylene carbonate, polyethylene oxide, etc.) in electrolyte, binder and / or additives separated and decomposed from the crushed material.

[0091] The decomposition unit for performing this comprises a supercritical CO2 maintenance unit; a CO2 capture unit for capturing gas-phase treated CO2; a cooling unit for separating a cooled solution from the gas-phase treated CO2; and a CO2 recapture transport unit for recapturing the gas-phase CO2 from which the cooled solution has been separated and transporting it to a water leaching unit; and the CO2 capture unit includes a cooling unit and a solution collection unit for collecting the cooled solution from the gas-phase treated CO2.

[0092] The above decomposition treatment (decomposition section) may contain CO2 used in the passivation process within the shredded material, and supercritical CO2 is injected into the decomposition section and performed under conditions where the injected supercritical CO2 can maintain a supercritical state. For example, the supercritical CO2 is injected at 60°C and 105 atm, and the decomposition treatment is performed under conditions where the pressure within the decomposition section maintains this pressure.

[0093]

[0094] To explain the decomposition process in more detail, the crushed material transferred from the second stage into the decomposition tank containing supercritical CO2 is introduced, and the electrolyte, binder and / or additives in the crushed material are dissolved and decomposed, and separated from the crushed material. Then, when the pressure in the decomposition tank is gradually lowered, the supercritical CO2 is converted into gaseous CO2, and the converted CO2 contains the components decomposed from the electrolyte, binder and / or additives. This gaseous CO2 is captured in the CO2 capture unit, transferred to the cooling unit, and then cooled to generate a cooled solution. Then, the cooled solution recaptures the separated gaseous CO2 and transfers it to the water leaching unit for recycling. In addition, by collecting the cooled solution, it is possible to separate and obtain carbonates and organic acid salts, lithium salts, organic solvents, additives, etc. in the crushed material.

[0095]

[0096] Next, step 4 is a process of heat-treating the stabilized crushed material to obtain a heat-treated crushed material containing lithium oxide and lithium fluoride. When the crushed material is heat-treated, residual impurities such as organic substances and binders are removed, and lithium in the cathode material is separated, resulting in phase separation into Li2CO3, Li2O, and / or LiF. For example, phase separation may occur through a reaction such as the following reaction scheme 1.

[0097] [Reaction Formula 1]

[0098] LiNix Co y Mn z (Cathode material) + CO2 → Li2CO3, Li2O and / or LiF

[0099] The above heat treatment is performed in a heat treatment section, and like the passive section and the crushing section, it is a closed process, and is configured with a box-type heat treatment furnace, a tunnel-type heat treatment furnace, a vertical furnace, a vertical rotary furnace, or a rotary kiln-type heat treatment furnace. Preferably, it may be configured with a vertical rotary heat treatment furnace, and more preferably, it may be configured with an electric furnace-type vertical rotary heat treatment furnace to prevent oxidation and to avoid being affected by the external atmosphere.

[0100] In addition, the heat treatment section may also be equipped with a mixed gas inlet of N2 and CO2, similar to the passive section and the crushing section, or may be equipped with a separate N2 inlet and a CO2 inlet.

[0101] In the passivation treatment in step 1, the crushing treatment in step 2, the disassembly treatment in step 3, and the heat treatment in step 4, the electrolyte of the battery is decomposed by supercritical CO2 or low-temperature gas / liquid and solid CO2 introduced in each of the above steps, and not only the electrolyte but also the Li component in other battery components forms reaction products such as Li2CO3, which do not volatilize and are recovered without loss.

[0102] In addition, the heat treatment is performed under an oxygen-free atmosphere, specifically, under a mixed gas of 10 to 30 volume% of the carbon precursor and the remaining balance of 100 volume%, and preferably, under a mixed gas of 13 to 27 volume% of the carbon precursor and the remaining balance of 100 volume%.

[0103] The above carbon precursor may use a carbon-based material such as graphite.

[0104] And, the mixed gas contains H2, CO2 and N2 in a molar ratio of 0.02 to 0.06: 0.15 to 0.35: 0.41 to 0.87, preferably H2, CO2 and N2 can be included in a molar ratio of 0.02 to 0.05: 0.20 to 0.30: 0.55 to 0.78. At this time, if CO2 is less than 0.15 molar ratio by volume, there may be a problem of low reaction, and if it exceeds 0.35 molar ratio, a large amount of unreacted CO2 is generated, which is uneconomical. Therefore, it is advantageous to perform heat treatment by inputting and controlling H2, CO2, and N2 so as to satisfy the above molar ratio.

[0105] In addition, the above heat treatment can be performed at 200 to 1,150°C for 30 to 360 minutes or at 600 to 1,150°C for 30 to 360 minutes, and since the phase separation conditions are different depending on the main material of the waste being heat treated, the heat treatment temperature conditions can be adjusted differently.

[0106] As a preferred embodiment of the present invention, the heat treatment may be performed stepwise at a temperature of 200 to 1150°C when the shredded material is a mixed or individual battery of an NCM (lithium nickel manganese) battery, an NCA (ternary lithium) battery, an LCO (lithium cobalt oxide) battery, an LMO (lithium manganese nickel oxide) battery, or an LFP (lithium iron phosphate) battery.

[0107] Another preferred embodiment is that, when the shredded material is shredded material from an NCM (lithium nickel manganese) battery, an NCA (ternary lithium) battery, or an LCO (lithium cobalt oxide) battery, the heat treatment is performed at a temperature of 600 to 800°C, and when the shredded material is shredded material from an LMO (lithium manganese nickel oxide) battery or an LFP (lithium iron phosphate) battery, the heat treatment can be performed at a temperature of 850 to 1150°C.

[0108] In this way, the heat-treated shredded material in the heat treatment unit contains battery black mass and other impurities including Co, Ni, Mn, Al, Cu, Fe, Li2CO3.

[0109]

[0110] Next, a process is performed to obtain battery black mass containing Li2CO3 by separating and sorting the heat-treated shredded material in the 5th step. The heat-treated shredded material contains Co, Ni, Mn, Al, Cu, Fe, battery black mass, and other impurities. Among these, shredded material lighter than battery black mass is subjected to air classification, shredded material heavier than battery black mass (Co, Ni, Mn, Al, Cu, Fe, etc.) is subjected to particle size separation, and reduced substances in the black mass are removed by magnetic sorting.

[0111] As a preferred example, the separation and selection treatment of the heat-treated crushed material in step 5 may include step 5-1 of subjecting the heat-treated crushed material to air classification to obtain crushed material from which crushed material lighter than black mass has been removed; step 5-2 of subjecting the crushed material obtained through step 5-1 to particle size separation to obtain black mass from which crushed material heavier than black mass has been removed; and step 5-3 of subjecting the black mass obtained through step 5-2 to magnetic selection to obtain black mass including Li2CO3 from which reduced substances in the black mass have been removed. At this time, the heavy crushed material in step 5-2 may include one or more metals selected from Co, Ni, Mn, Al, Cu, and Fe.

[0112] The above 5 steps are performed in a classification unit, and in order to perform steps 5-1 to 5-3 as described above, the classification unit includes an air classification unit that performs the step 5-1 process; a particle size separation classification unit that performs the step 5-2 process; and a magnetic separation unit that performs the step 5-3 process.

[0113] In addition, the air classification unit may be composed of a plurality of air classification units, and through air classification, black mass and materials lighter than the black mass and materials heavier than the black mass can be separated, and at the same time, a cooling effect of the material after heat treatment can be secured. In addition, the material obtained through the air classification in step 5-1 can be obtained as a crushed product in a state in which about 70 to 90% of the black mass and the remaining amount of impurities (Co, Ni, Mn, Al, Cu, Fe, etc.) are mixed.

[0114] In addition, the particle size separation classifying unit may be equipped with a plurality of plate-shaped or circular vibrating screens and a plurality of ultrasonic devices, and the vibrating screen is a method of obtaining black mass by separating heavy crushed materials through particle size separation of black mass, and the vibrating screens are laminated in multiple layers, and the vibrating screens of each layer may be laminated so that the mesh size of the vibrating screen gradually decreases from the material obtained and supplied from the air classification unit.

[0115] And, the vibrating screen has a mesh size in the range of 10 to 200 mesh, preferably in the range of 20 to 100 mesh, more preferably D of black mass 50 Considering the particle size, the mesh size can be 30 to 70.

[0116] Additionally, the particle size separation classifier may be additionally equipped with an ultrasonic device to prevent clogging.

[0117] Additionally, the classification unit performing the five-step separation and selection process may be further equipped with a pin mill crushing unit to further crush large-sized black mass.

[0118] Battery black mass containing Li2CO3 obtained by performing a 5-step process can be used and sold as a recycled product itself, and Li2CO3 crystals can also be manufactured by performing the following process.

[0119]

[0120] Next, step 6 is a process of leaching battery black mass containing Li2CO3 to convert Li2CO3 in the black mass into LiHCO3, thereby producing an aqueous solution containing LiHCO3 dissolved in water, which is performed in a leaching unit. The leaching reaction is a process of crushing black mass to make the particle size smaller so that lithium can be easily separated, and adding CO2 to convert Li2CO3 into LiHCO3 and ensure that LiHCO3 is well dissolved in water.

[0121] The above-mentioned water leaching unit comprises a water leaching reactor, balls for a ball mill in the water leaching reactor, a CO2 injection unit, a fluorine removing agent and an impurity removing agent injection unit, and a pressure reducing device. The water leaching reactor may be a cylindrical water leaching reactor or a stirred water leaching reactor separately equipped with a stirrer. In this case, the CO2 injected into the CO2 injection unit may include CO2 that is unreacted among the CO2 used in the heat treatment and is reinjected into the water leaching unit.

[0122] To be more specific, after introducing water, balls for a ball mill, and black mass containing Li2CO3 obtained in step 5 into a water leaching reactor, CO2 is introduced, and the water leaching reaction is performed under conditions of a rotation speed of the water leaching reactor or a stirrer rotation speed of 50 to 400 rpm and a temperature of 0 to 50°C for 30 minutes to 5 hours, preferably under conditions of a rotation speed of the water leaching reactor or a stirrer rotation speed of 50 to 200 rpm and a temperature of 0 to 40°C for 30 minutes to 2 hours, and more preferably under conditions of a rotation speed of the water leaching reactor or a stirrer rotation speed of 50 to 200 rpm and a temperature of 0 to 25°C for 30 minutes to 2 hours.

[0123] And, it is appropriate to add black mass containing water and Li2CO3 in a weight ratio of 1:1 to 10, preferably in a weight ratio of 1:3 to 5.

[0124] In addition, the CO2 injected into the water leaching reactor reacts with water to become a weak acid state and is converted into H2CO3, which is used to convert Li2CO3 into a liquid with high solubility, LiHCO3. The CO2 injected into the water leaching reactor can be gaseous CO2 or an aqueous solution in which CO2 is dissolved. When liquid CO2 is injected, the appropriate CO2 injection (injection) speed is about 100 to 120 ml / min. If the injection speed is less than 100 ml / min, the dissolution speed and saturation may be affected.

[0125] And, when an aqueous solution containing dissolved CO2 (CO2 aqueous solution) is injected, the concentration of CO2 in the aqueous solution is 0.10 to 4.00 mol / L, preferably 0.20 to 2.00 mol / L, and more preferably 0.50 to 1.35 mol / L.

[0126] In addition, the amount of the aqueous solution (CO2 aqueous solution) in which the CO2 is dissolved is 20 to 100 ml, preferably 20 to 60 ml, and more preferably 25 to 50 ml per 1 L of the water introduced into the water leaching reactor, which is advantageous in terms of maintaining the appropriate pH range for the reaction and securing a high concentration of lithium in the LiHCO3 aqueous solution.

[0127] In addition, the above water leaching reaction is advantageous in terms of the solubility of LiHCO3 in water as the pressure increases at a pH of 5 to 7, and it is advantageous in terms of securing a high concentration of lithium in the LiHCO3 aqueous solution to perform it under a pressure of 1 to 5 atm, preferably 1 to 3 atm, and more preferably 1 to 2 atm.

[0128] In addition, it is preferable to use balls for the ball mill having a particle size of 5 to 50 cm, preferably 10 to 20 cm, in terms of grinding efficiency. In addition, balls for the ball mill can be made of general materials used in the art, and a preferred example is an alumina ball.

[0129] In addition, the water leaching reaction may be performed in parallel with ultrasonic treatment together with a ball mill, and at this time, the water leaching reactor may be additionally equipped with an ultrasonic device.

[0130] Next, step 7 is a process for increasing the concentration of LiHCO3 by removing fluorine (F) in an aqueous solution containing LiHCO3 that has undergone a water leaching process. If F in the aqueous solution is not removed, the purity of the Li2CO3 crystals may decrease, which may lead to a problem of reduced marketability.

[0131] The above water leaching process may be performed by introducing and reacting a fluoride removing agent and an impurity removing agent into the water leaching reactor of the water leaching unit in which step 6 has been performed, or by introducing the aqueous solution obtained by solid-liquid separation in the water leaching reactor into a separate reactor, and then introducing and reacting the fluoride removing agent and the impurity removing agent. Preferably, the process is performed by introducing and reacting a fluoride removing agent and an impurity removing agent into the water leaching reactor of the water leaching unit in which step 5 has been performed.

[0132] In addition, the input section for inputting the fluoride remover and the impurity remover may be configured as one input section, or may be configured as separate input sections for the fluoride remover input section and the impurity remover input section.

[0133] The above fluoride removing agent may include at least one selected from Ca(OH)2, CaO, K(OH)2 and K2O, preferably at least one selected from Ca(OH)2 and CaO, and more preferably Ca(OH)2 may be used.

[0134] The above impurity remover may use Na2CO3.

[0135] A preferred embodiment using Ca(OH)2 as a fluoride removal agent is as follows: 30 minutes after completion of the water leaching reaction, preferably 1 hour later, Ca(OH)2 as a fluoride removal agent and Na2CO3 as an impurity removal agent are added to a water leaching reactor containing an aqueous solution containing LiHCO3, and then the reaction can be performed for 30 minutes to 2 hours under conditions of a rotation speed of the water leaching reactor or a stirrer rotation speed of 50 to 400 rpm and a temperature of 10 to 50°C. When Ca(OH)2 is added, the pH increases slightly, and due to the increased pH, F - Go Ca 2+ It reacts with CaF2 to produce and increase the particle size to form crystals. Then, the crystallized CaF2 is removed during the 8-step solid-liquid separation treatment.

[0136]

[0137] Next, step 8 is a process of obtaining a LiHCO3 aqueous solution by removing waste scrap and impurities, which are solids in an aqueous solution containing LiHCO3 from which fluorine has been removed, through solid-liquid separation treatment, and the impurities include solidified Co, Ni, Mn, Al, Cu, Fe, CaF2, etc. and compounds containing these elements.

[0138] And, the solid-liquid separation treatment is performed in a solid-liquid separation unit consisting of a filter press, centrifuge, or vacuum filter, and can preferably be performed using a filter press.

[0139] The above filter press is equipped with a pressure device, air, N2 and CO2 inlet (blowing) to lower the moisture content, and includes a washing process using pure water and / or ultrapure water, etc., and can maintain the moisture content at 2 wt% or less, so there is no loss of lithium.

[0140] And, the LiHCO3 aqueous solution obtained by performing step 8 has a lithium concentration of about 0.30 to 1.50, preferably about 0.50 to 1.50 wt%, and more preferably about 0.50 to 1.20 wt%.

[0141]

[0142] Next, step 9 is a process of crystallizing LiHCO3 into Li2CO3 by introducing the LiHCO3 aqueous solution obtained by performing step 8 into a reactor of a crystallization unit and then treating it with microwaves.

[0143] The above microwave treatment is performed under a vacuum atmosphere and at a temperature of 40 to 70°C. At this time, if the temperature is lower than 40°C, there may be a problem of poor crystallization into Li2CO3 or a low yield, and if it exceeds 70°C, there may be a problem of low proportion of plate-shaped crystals.

[0144] And, in order to raise and maintain the temperature, the LiHCO3 aqueous solution is irradiated with microwaves of 600 to 1200 W and stirred at a stirring speed of 100 to 400 rpm, preferably irradiated with microwaves of 800 to 1100 W, more preferably irradiated with microwaves of 900 to 1100 W and stirred at a stirring speed of 200 to 320 rpm. At this time, if the microwave intensity exceeds 1200 W or the stirring speed exceeds 400 rpm, there may be a problem that the plate-shaped crystal formation ratio is lowered, and if the microwave intensity is less than 600 W, the plate-shaped crystal ratio increases, but the reaction time becomes too long, and there may be a problem that the homogeneity of the plate-shaped crystal shape is rather reduced.

[0145] In addition, the microwave treatment is appropriate in terms of forming plate-like crystals when performed under a vacuum atmosphere of 0.1 to 10 bar, preferably 1.0 to 7.0 bar, more preferably 1.5 to 5.0 bar. If the pressure is less than 0.1 bar, there is no effect of increasing the ratio of plate-like crystals, and even if it exceeds 10 bar, there may be no effect of increasing the ratio of plate-like crystals.

[0146]

[0147] When microwave treatment is performed, satisfying the microwave irradiation intensity, stirring speed, and vacuum atmosphere is advantageous in terms of increasing the proportion of plate-shaped crystals in the crystallized Li2CO3 crystals and improving the homogeneity of the plate-shaped crystal shape.

[0148]

[0149] Next, step 10 is a process of dehydrating the solution containing Li2CO3 crystals by microwave treatment in step 9 to obtain Li2CO3 crystals and washing them. The dehydration and washing may be repeated one or more times. At this time, the dehydration and washing may be performed by a general method used in the art, and the washing is performed using pure water and / or ultrapure water.

[0150]

[0151] *In addition, the dehydration solution and / or washing solution used for dehydration and washing are reintroduced into the 6-stage water leaching unit and reused, thereby enabling the recovery of dissolved lithium and minimizing the generation of wastewater, thereby ensuring an environmentally friendly process that does not generate wastewater and does not cause lithium loss.

[0152]

[0153]

[0154] *In addition, the present invention can further perform a process of drying the Li2CO3 crystals obtained by performing dehydration and washing in step 10, and the drying process can be performed by a general method used in the art, for example, natural drying, hot air drying, etc., and is not particularly limited.

[0155]

[0156] The lithium carbonate (Li2CO3) crystal of the present invention manufactured through the method and system described above has a particle size D 50 This can be 45 to 55㎛.

[0157] In addition, the purity of the lithium carbonate crystals may be 99.00% or higher, and preferably 99.00 to 99.99%.

[0158] In addition, the lithium carbonate crystals have a very high proportion of plate-shaped crystals, and specifically, the lithium carbonate crystals may contain 50 wt% or more of plate-shaped crystals, and preferably 70.0 to 99.9 wt% of plate-shaped crystals and 0.1 to 30.0 wt% of rod-shaped crystals.

[0159]

[0160] The lithium carbonate crystals recycled through the method and system described above are high-quality battery-grade lithium carbonate materials, and can be used to manufacture cathode materials (cathode powder, cathode active material, etc.) for lithium-ion batteries, thereby producing lithium-ion batteries with excellent performance.

[0161]

[0162] The present invention will be described in more detail below through examples. However, the following examples are intended to aid understanding of the present invention and should not be construed as limiting the scope of the present invention.

[0163] [Example]

[0164] Example 1: Confirmation of ignition conditions during passivation and crushing treatment

[0165] NCM (lithium nickel manganese) battery modules were prepared as waste.

[0166] The above waste was fed into a sealed conveyor, and through the conveyor, the waste was fed into a passivation unit consisting of a box-type cooling device for passivation treatment. The box-type cooling device is equipped with a nozzle into which a mixed gas of -60°C N2 and -70°C CO2 is fed, and the mixed gas is a mixture of CO2 and N2 in a volume ratio of 1:4.0.

[0167] In addition, during the passivation treatment, the internal air of the box-type cooling device was composed and maintained of various conditions such as oxygen (O2), CO2, and N2 as shown in Table 1 below, and the passivation treatment was performed under conditions where the internal temperature of the box-type cooling device was maintained at -90°C, -60°C, -30°C, 0°C, and 30°C, respectively.

[0168] Next, the passivated lithium-ion battery waste was fed into a sealed shredder consisting of a two-axis shredder. The interior of the sealed shredder was maintained at the same internal atmosphere and temperature as the box-type cooling device. Furthermore, the occurrence of ignition during the shredding process was confirmed.

[0169] Temperature inside the cooling device and inside the crushing device N2 (vol%) Supercritical or low temperature gas / liquid and solid CO2 (vol%) O2 (vol%) During crushing After crushing (within 5 minutes) 30℃ 50 20 30 Ignition Ignition 60 20 20 Ignition Ignition 70 20 10 Ignition Ignition 75 20 5 Ignition Ignition 80 200 Non-ignition Ignition 0℃ 50 20 30 Ignition Ignition 60 20 20 Ignition Ignition 70 20 10 Ignition Ignition 75 20 5 Ignition Ignition 80 200 Non-ignition Ignition -30℃ 50 20 30 Ignition Ignition 60 20 20 Ignition Ignition 70 20 10 Non-ignition Ignition 75205 Not Ignition Not Ignition 80200 Not Ignition Not Ignition -60℃ 502030 Not Ignition Not Ignition 602020 Not Ignition Not Ignition 702010 Not Ignition Not Ignition 75205 Not Ignition Not Ignition 80200 Not Ignition Not Ignition -90℃ 502030 Not Ignition Not Ignition 602020 Not Ignition Not Ignition 702010 Not Ignition Not Ignition 75205 Not Ignition Not Ignition 80200 Not Ignition Not Ignition

[0170] Looking at Table 1 above, it was confirmed that no ignition occurred when the internal temperature of each device was -30°C or lower and the oxygen concentration was 5% by volume or lower during passivation and shredding treatments. Therefore, it was confirmed that it is advantageous to perform passivation and shredding treatments at -70 to -30°C, preferably -40 to -60°C, and under conditions where O2 is 5% by volume or lower, from the perspectives of economic efficiency and non-ignition.

[0171] Example 2: Preparation of lithium carbonate crystals from spent lithium-ion batteries

[0172] NCM (lithium nickel manganese) battery modules were prepared as waste.

[0173] The waste was fed into a sealed conveyor, and through the conveyor, the waste was fed into a drying treatment unit consisting of a box-type cooling device for passivation treatment. The box-type cooling device is equipped with a nozzle into which a mixed gas of -60°C N2 and -70°C CO2 is fed, and the mixed gas is a mixture of CO2 and N2 in a volume ratio of 1:4.0. In addition, during the passivation treatment, the internal air of the box-type cooling device is oxygen (O2). Passivation treatment was performed under conditions in which the remaining amount of CO2 and N2 was maintained at 5% by volume or less and 100% by volume or less, and the internal temperature of the box-type cooling device was maintained at -40 to -60°C.

[0174] Next, the passivated lithium-ion battery waste was fed into a sealed shredder consisting of a two-axis shredder. The interior of the sealed shredder was maintained at the same internal atmosphere and temperature as the box-type cooling device. The battery waste was then crushed to obtain crushed materials measuring 0.1 to 15 cm in size.

[0175] Next, the crushed material was introduced into a decomposition unit containing supercritical CO2 while maintaining the same air and temperature as above, and mixed for about 120 minutes under conditions where supercritical CO2 was maintained at a temperature of 60°C and 105 atm, thereby dissolving and decomposing the electrolyte and binder contained in the crushed material with supercritical CO2.

[0176] Specifically, carbonates and organic acid salts (ethylene carbonate, diethyl carbonate, dimethyl carbonate, propylene carbonate, etc.), lithium salts (hexafluorophosphate, lithium tetrafluoroborate), organic solvents (methyl ethyl carbonate, ethyl metal carbonate, etc.), and additives (fluoroethylene carbonate, vinylene carbonate, polyethylene oxide, etc.) contained in the above electrolyte and binder are dissolved in supercritical CO2.

[0177] Next, the pressure in the decomposition tank where the electrolyte and binder were decomposed was gradually reduced through decomposition, and the CO2 and gaseous electrolyte gasifying in the decomposition tank were passed through a cooling device to collect the electrolyte. At this time, the gaseous CO2 was transferred to a water leaching reactor.

[0178] Then, the decomposed electrolyte and binder in the decomposition section were removed or separated from the pulverized material and transferred to a heat treatment furnace.

[0179] Next, the above-mentioned pulverized material is treated with H2, CO2, and After being injected into an electric furnace-type rotary kiln-type heat treatment furnace with N2 gas injected at a molar ratio of 0.04:0.24:0.72, heat treatment was performed at 640°C for 120 minutes, including 15 volume % of carbon precursor relative to the reactant.

[0180] At this time, C (graphite) was used as a carbon precursor for lithium carbonation.

[0181] The heat-treated waste contained battery black mass and other impurities including Co, Ni, Mn, Al, Cu, Fe, Li2CO3.

[0182] Next, the heat-treated crushed material was fed into a classification unit for separation and sorting, and the classification unit is composed of a plurality of air classification units (see A in Fig. 2), a particle size separation classification unit equipped with a plurality of circular vibrating screens (40 mesh) and a plurality of ultrasonic devices (see B in Fig. 2), and a magnetic separation unit.

[0183] In the air classification unit, battery black mass and shredded material (material) were separated / removed, and the shredded material that was air classified was a shredded material that was mixed with approximately 80% black mass and the remaining amount of impurities (Co, Ni, Mn, Al, Cu, Fe, etc.).

[0184] Then, the air-classified crushed material was subjected to particle size separation to remove crushed material heavier than black mass, thereby obtaining black mass. At this time, the crushed material having a large particle size and being heavy contains metals such as Co, Ni, Mn, Al, Cu, and Fe.

[0185] And, the metal obtained through particle size separation treatment was magnetically separated from the black mass to remove Fe and reduced materials from the black mass.

[0186] Next, the battery black mass containing Li2CO3 obtained through separation and selection was introduced into a cylindrical water leaching reactor for water leaching treatment, and then water and alumina balls (particle size 15 cm) for ball milling were introduced, and then CO2 recovered from the decomposition section was liquefied and introduced into the water leaching reactor.

[0187] At this time, the CO2 input was in the form of an aqueous solution (CO2 concentration 1.00 mol / L) at 39.97 ml per 1 L of water, and the water leaching reaction was performed for 1 hour under the conditions of a water leaching reactor rotation speed of 100 rpm, room temperature (20°C), and atmospheric pressure (1 atm). At this time, the battery black mass input amount was 4 weight ratios with respect to 1 weight ratio of water. In addition, the water leaching reaction was performed under conditions where a pH of approximately 6.0 was maintained.

[0188] Next, after 1 hour from the completion of the water leaching process, Ca(OH)2 as a fluoride removal agent and Na2CO3 as an impurity removal agent were injected into the water leaching reactor, and then the fluoride removal treatment process was performed for 40 minutes under the conditions of a water leaching reactor rotation speed of 100 rpm, 20°C, and a reduced pressure of 150 mbar, and CaF2 crystallization was performed, so that F and dissolved impurities dissolved in the aqueous solution were removed.

[0189] Next, the solid waste scrap and impurities in the aqueous solution containing LiHCO3 from which fluorine was removed were removed by performing a filter press on the solid solution that had undergone the fluorine removal process, thereby obtaining a LiHCO3 aqueous solution. The impurities include solidified Co, Ni, Mn, Al, Cu, Fe, CaF2, etc., or compounds containing any one or more of these elements.

[0190] The LiHCO3 aqueous solution obtained through high-temperature separation had a lithium concentration of 0.70 wt%.

[0191] Next, the obtained LiHCO3 aqueous solution was put into a microwave reactor, and the inside of the reactor was made into a 2.0 bar vacuum atmosphere, and then microwaves with an intensity of 1000 W were irradiated to raise the temperature to 70℃, and then the LiHCO3 in the aqueous solution was stirred at 300 rpm while maintaining the temperature for 15 minutes. Crystallization treatment was performed with Li2CO3.

[0192] Next, the supernatant containing the precipitate was collected from the solution in which the crystallization treatment was completed, and then dehydrated to obtain Li2CO3 crystals, which were then washed three times with water.

[0193] Then, the washed Li2CO3 crystals were placed in an oven at 50°C to completely dry them, thereby obtaining dried Li2CO3 crystals.

[0194] The obtained Li2CO3 crystals have particle size D 50This was 50.2㎛, the purity of Li2CO3 was 99.9%, and the plate-shaped crystals in the crystal were 75.2 wt% and the rod-shaped crystals were 24.8 wt%.

[0195]

[0196] Examples 3 to 10 and Comparative Examples 1 to 7

[0197] Li2CO3 crystals were obtained by recycling NCM battery module waste in the same manner as in Example 2, but the conditions for crystallization were changed as shown in Table 2 below to manufacture Li2CO3 crystals.

[0198] And, the Li2CO3 precipitation rate, the proportion of plate-shaped and rod-shaped crystals in the Li2CO3 crystals, and the purity are shown in Table 2 below.

[0199] At this time, the Li2CO3 precipitation rate was measured according to the following equation 1.

[0200] [Formula 1]

[0201] Li2CO3 precipitation rate (%) = (amount of lithium precipitated in the crystallized solution / amount of lithium in the solution before crystallization) × 100%

[0202] Classification Microwave (crystallization) treatment conditions Li2CO3 crystal pressure (bar) Irradiation intensity (W) Stirring speed (rpm) Temperature (℃) Li2CO3 precipitation rate (%) Li2CO3 purity (%) Plate-shaped: Rod-shaped crystal content ratio Example 2 2 1 0 0 3 0 0 8 1.6 9 9 7 5.2 : 24.8 Example 3 1 0 1 0 0 3 0 0 7 0 7 0.5 9 9 5 8.6 : 41.4 Example 4 5 0 1 0 0 3 0 0 7 0 8 2.6 9 9 7 8.5 : 21.5 Example 5 2 8 2.0 3 0 0 7 0 8 1.5 9 9 7 2.5 : 27.5 Example 6 2 1 1 5 0 3 0 0 7 0 8 1.6 9 9 7 6.2 : 23.8 Example 7 210001 20708 1.5 99.9 7 6.5 : 23.5 Example 8 21000350708 1.6 99.9 7 2.6 : 27.4 Example 9 210003004060.499.47 8.5 : 21.5 Example 10 210003006070.29 8.8 7 7.0 : 23.0 Comparative Example 110.2 1000300708 2.7 99.9 7 8.3 : 21.7 Comparative Example 22580300708 1.5 99.9 4 0.1 : 59.9 Comparative Example 321250300708 1.5 99.9 6 8.4 : 31.6 Comparative Example 421000507081.599.949.6 :50.4 Comparative Example 5210005007081.599.947.2 :52.8 Comparative Example 6210003003549.898.236.2 :63.8 Comparative Example 7210003008077.299.972.8 :27.2

[0203] As shown in Table 2, it was confirmed that the Li2CO3 crystals manufactured in Examples 2 to 10 had a purity of 99.0% or higher, and in particular, the weight ratio of plate-shaped crystals was 50% or higher by weight, preferably 70% or higher. In contrast, in Comparative Example 1, which was performed under conditions where the pressure exceeded 10 bar during the crystallization process, there was no increase in plate-shaped crystals compared to Example 4, which was performed at 5 bar.

[0204] In addition, in the case of Comparative Example 2, which was performed by irradiating microwaves at an intensity of less than 600 W, there was a problem that the weight ratio of plate-shaped crystals was very low, less than 50 wt%, and in the case of Comparative Example 3, which was performed by irradiating microwaves at an intensity of 1250 W, which is less than 1000 W, there was a problem that the ratio of plate-shaped crystals formed was rather low, compared to Example 6, which was performed by irradiating microwaves at an intensity of 1150 W. This is believed to be because the temperature was raised so high that the reactivity was too high, which rather hindered the formation of the plate-shaped crystal structure.

[0205] In addition, in Comparative Example 4 performed under conditions where the stirring speed was less than 100 rpm and Comparative Example 5 performed under conditions where the stirring speed exceeded 400 rpm, there was a problem that the proportion of plate-shaped crystals was relatively low compared to Examples 7 and 8, respectively. In the case of Comparative Example 4, it is judged that the crystals were not sufficiently formed in a plate-shaped form due to insufficient reactivity, and in the case of Comparative Example 5, it is judged that the proportion of plate-shaped crystals was low due to problems such as the crystals colliding with each other and breaking because the stirring speed was too fast.

[0206] In addition, in the case of Comparative Example 6, which was performed at 35°C, which is less than 40°C, the proportion of plate-shaped crystals was relatively significantly lower compared to Examples 1 and 9 to 10, and in the case of Comparative Example 7, which was performed at 80°C, which is more than 70°C, the proportion of plate-shaped crystals was rather lower compared to Example 1.

[0207]

[0208] Example 11

[0209] Battery black mass containing Li2CO3 was obtained from NCM battery module waste using the same method as in Example 2, and then a water leaching process and a fluorine removal treatment process were performed. However, when performing the water leaching process, the CO2 input amount, pH, pressure, and temperature were varied as shown in Tables 3 to 5 below, and each was obtained.

[0210] Then, each of the obtained solids was subjected to a filter press to remove waste scrap and impurities, which are solids in the aqueous solution containing LiHCO3 from which fluorine was removed, thereby obtaining a LiHCO3 aqueous solution, and the lithium concentration in the obtained LiHCO3 aqueous solution is shown in Tables 3 to 5 below.

[0211] Water leaching reaction (5 steps) Conditions (temperature 20℃) Amount of lithium dissolved in LiHCO3 aqueous solution (wt%) Ball mill ball particle size (cm) CO2 concentration in CO2 aqueous solution (mol / L) Amount of CO2 aqueous solution added per 1 L of water (ml) pH pressure (atm) 150.2 7.99 7.2 10.13 0.5 19.99 6.7 50.34 0.83 1.97 6.30.5 51.03 9.97 6.0 0.7 0 1.3 51.96 5.5 50.90 1.5 59.96 5.2 51.04 1.7 6 7.95 4.9 51.06

[0212] Looking at the measurement results in Table 3 above, as the CO2 concentration in the CO2 solution and the amount of CO2 solution injected increased, the pH tended to decrease and the amount of lithium dissolved in the LiHCO3 solution tended to increase. However, when the CO2 concentration in the CO2 solution was high and the amount of CO2 solution injected was high so that the pH was less than 5.0, the amount of lithium dissolved in the LiHCO3 solution did not increase compared to the amount of CO2 injected.

[0213] The CO2 concentration in the CO2 solution was 1.0 mol / L, the amount of CO2 solution injected was 39.97 ml, and the water leaching reaction pressure and temperature were changed to perform the water leaching reaction as shown in Tables 4 and 5 below.

[0214] Water leaching reaction (step 5) Conditions (temperature 20℃ / pH 6.0) Amount of lithium dissolved in LiHCO3 aqueous solution (wt%) Ball mill ball particle size (cm) CO2 concentration in CO2 aqueous solution (mol / L) Amount of CO2 aqueous solution added per 1 L of water (ml) Pressure (atm) 151.03 9.97 10.70 20.82 50.90 70.94 100.97 121.01

[0215] Water leaching reaction (step 5) Conditions (pH 6.0 / 1 atm) Amount of lithium dissolved in LiHCO3 aqueous solution (wt%) Ball mill ball particle size (cm) CO2 concentration in CO2 aqueous solution (mol / L) Amount of CO2 aqueous solution added per 1 L of water (ml) Temperature (℃) 151.0 39.9 721.10 200.70 400.55 600.41 800.34

[0216] Looking at Tables 4 and 5 above, as the pressure increases, the amount of lithium dissolved in the LiHCO3 aqueous solution increases. However, when the pressure exceeds 5 atm, the rate of increase in the amount of dissolved lithium tends to decrease significantly compared to the amount of pressure increase. Through this, it was confirmed that it is economical to perform the reaction at a pressure of 5 atm or less, preferably 3 atm or less, and more preferably 2 atm or less. In addition, as the temperature decreases during the water leaching reaction, the amount of dissolved lithium tends to increase. When it exceeds 50°C, the amount of dissolved lithium was too low, less than 0.50 wt%. Through this, it was confirmed that it is advantageous to perform the water leaching reaction at 50°C or less, preferably 30°C or less.

[0217]

[0218] Manufacturing Example 1: Manufacturing of a lithium secondary battery

[0219] Using the recycled lithium carbonate obtained in Example 2, a lithium secondary battery coin cell was manufactured and evaluated as follows, and the results are shown in Table 6 below.

[0220] Then, the charge / discharge capacity, efficiency, and charge / discharge rate of the manufactured lithium secondary battery after 50 charge / discharge cycles were measured, and the results are shown in Table 6 below.

[0221] (1) A precursor was used in a ratio of NCM 532 and 622, and mixed and synthesized with lithium carbonate recycled in Example 2 to manufacture a cathode powder.

[0222] (2) A coin cell battery was manufactured using lithium metal as the negative electrode.

[0223] (3) For the manufacture of lithium secondary batteries, LiPf6 was used as the electrolyte, and a mixture of EC (ethylene carbonate), DMC (dimethyl carbonate), DEC (diethyl carbonate), and EMC (ethyl methyl carbonate) was used as the organic solvent.

[0224] A PE / PP type separator was prepared as a separator.

[0225] A lithium secondary battery coin cell was manufactured using the positive electrode powder, negative electrode, electrolyte, and separator manufactured using the above precursor and recycled lithium carbonate, respectively.

[0226] Battery performance made of recycled lithium carbonate: Charge capacity mAh / g 184~188 186 Discharge capacity mAh / g 150~160 161 Efficiency % 85~86 88 Lifespan (50 cycles) % 97~98 97.5 Temperature 40℃ 40℃ 40℃

[0227] Through the above examples and experimental examples, it was confirmed that the recycled lithium carbonate crystals of the present invention have higher purity than battery-grade lithium carbonate mined from existing mines, and have a higher proportion of plate-shaped crystals than lithium carbonate obtained from battery recycling, and thus can exhibit characteristics equivalent to or superior to those of lithium-ion secondary batteries manufactured with recycled lithium carbonate in terms of lithium battery performance, such as charging capacity, efficiency, and lifespan, compared to existing battery-grade lithium carbonate.

[0228] The best mode for carrying out the invention as described above has been described.

Claims

1. Input section for inputting lithium-ion battery waste; Passivation unit for passivating lithium-ion battery waste; A shredder for shredding passivated lithium-ion battery waste; A decomposition unit for decomposing binders, electrolytes and additives contained in shredded lithium-ion battery waste to obtain stabilized waste, and recovering at least one selected from among the decomposed organic solvents, electrolyte salts and additives; A heat treatment unit for heat-treating the above-mentioned stabilized crushed material to obtain a heat-treated crushed material; A classification unit that separates and sorts the heat-treated shredded material to separate battery black mass containing Li2CO3 and other shredded material; A water leaching unit that converts Li2CO3 in the black mass into LiHCO3 by introducing and reacting the black mass obtained from the classification unit into a water leaching reactor, thereby dissolving LiHCO3 in water, and performing a process of removing fluorine (F) in an aqueous solution containing LiHCO3; A solid-liquid separation unit for removing waste scrap and impurities from an aqueous solution containing LiHCO3 from which fluorine has been removed in a water leach unit, thereby obtaining a LiHCO3 aqueous solution; A crystallization unit that crystallizes LiHCO3 into Li2CO3 by microwave treatment of a LiHCO3 aqueous solution obtained through high-temperature separation treatment; and A dehydration / washing unit for obtaining Li2CO3 crystals by dehydrating and washing a crystallized Li2CO3-containing solution; A lithium carbonate recycling system from spent lithium-ion batteries, characterized in that a solution containing at least one selected from among dehydration and washing solutions generated in a dehydration / washing unit is reintroduced into a water leaching unit.

2. In paragraph 1, the lithium ion battery waste includes at least one selected from black mass, process scrap, battery cells, battery modules, and battery packs. A lithium carbonate recycling system from waste lithium-ion batteries, wherein each of the black mass, process scrap, battery cell, battery module and battery pack contains lithium.

3. In paragraph 1, each of the passivation section, crushing section, decomposition section and heat treatment section independently has an N2 and CO2 or mixed gas injection section, or has an N2 injection section and a CO2 injection section separately. A lithium carbonate recycling system from waste lithium-ion batteries, characterized in that the CO2 injected into each of the passivation section, crushing section, decomposition section, and heat treatment section is independently supercritical CO2 or gaseous CO2.

4. In the third paragraph, each of the N2 and CO2 does not contain moisture, A lithium carbonate recycling system from waste lithium-ion batteries, characterized in that the above N2 is injected at -70 to -50°C.

5. In paragraph 1, the input section is configured as a sealed conveyor, A lithium carbonate recycling system from waste lithium-ion batteries, characterized in that the passivation unit is comprised of a box-type cooling device equipped with a conveyor, a rotary kiln-type cooling device, or a screw-type cooling device.

6. In the third paragraph, the decomposition part, It is equipped with a supercritical CO2 maintenance device section; a CO2 capture section for capturing CO2 that has been gas-treated; a cooling section for separating a cooled solution from the gas-treated CO2; and a CO2 recapture transport section for recapturing the CO2 in the gas phase from which the cooled solution has been separated and transporting it to a water leaching section. A lithium carbonate recycling system from waste lithium-ion batteries, characterized in that the CO2 capture unit includes a cooling device unit and a solution collection unit that collects a cooled solution from the vapor-treated CO2.

7. In paragraph 1, each of the passivation treatment and the crushing treatment is performed in an atmosphere containing O25% by volume or less and the remaining amount of CO2 and N2 among 100% by volume, A lithium carbonate recycling system from waste lithium-ion batteries, characterized in that the above CO2 and N2 are contained in a volume ratio of 1:3.8 to 4.

4.

8. In paragraph 1, The above heat treatment unit is equipped with a box-type heat treatment furnace, a tunnel-type heat treatment furnace, a vertical heat treatment furnace, a vertical rotary heat treatment furnace, or a rotary kiln-type heat treatment furnace. The above heat treatment is performed under a mixed gas of 10 to 30 volume% of carbon precursor and the remaining balance of 100 volume%. The above mixed gas is H2, CO2 and A lithium carbonate recycling system from spent lithium-ion batteries, characterized in that it contains N2 in a molar ratio of 0.02 to 0.06: 0.15 to 0.35: 0.41 to 0.

87.

9. In paragraph 1, The above classification unit includes an air classification unit, a particle size separation classification unit, and a magnetic separation unit. The above air classification unit is composed of a plurality of air classification units, The particle size separation classifier is equipped with a plurality of plate-shaped or circular vibrating screens and a plurality of ultrasonic devices. A lithium carbonate recycling system from waste lithium-ion batteries, characterized in that the magnetic separation unit performs a process of magnetically separating and separating reduced materials in black mass obtained from a particle size separation classifier.

10. In the first paragraph, the water leaching unit, It is equipped with a water leaching reactor, balls for ball mill in the water leaching reactor, a CO2 injection port, a fluorine removal agent and impurity removal agent injection port, and a pressure reducing device. The above water leaching reactor is a cylindrical water leaching reactor or a stirred water leaching reactor equipped with a stirrer, A lithium carbonate recycling system from waste lithium-ion batteries, characterized in that the fluoride remover and impurity remover inputs are configured as one input or separate inputs.

11. A lithium carbonate recycling system from waste lithium-ion batteries, characterized in that it further comprises a drying unit for drying Li2CO3 crystals in the first paragraph.

12. Recovering high purity Li2CO3 from lithium-ion battery waste using a system selected from any one of clauses 1 to 11, A method for recycling lithium carbonate from waste lithium-ion batteries, characterized in that passivation treatment, crushing treatment, decomposition treatment and heat treatment are performed on waste lithium-ion batteries under a gas containing N2 and CO2.

13. Step 1: Passivation of lithium-ion battery waste; Step 2: Shredding passivated lithium-ion battery waste to produce shredded material with a particle size of 0.1 to 15 cm; Step 3: Decomposing and treating the electrolyte, binder and additives contained in the shredded lithium-ion battery waste, recovering the decomposed materials and obtaining stabilized shredded material; Step 4: heat treating the stabilized crushed material of Step 3 to obtain a heat-treated crushed material containing lithium oxide and lithium fluoride; Step 5 of separating and sorting the heat-treated crushed material to obtain battery black mass containing Li2CO3; Step 6 of introducing the above battery black mass into a water leaching reactor and subjecting it to a water leaching reaction to convert Li2CO3 in the black mass into LiHCO3 and produce an aqueous solution containing LiHCO3 dissolved in water; Step 7 of producing an aqueous solution containing LiHCO3 from which fluorine has been removed by removing fluorine (F) and impurities from an aqueous solution containing LiHCO3; Step 8 of performing solid-liquid separation treatment on an aqueous solution containing LiHCO3 from which fluorine has been removed to obtain a LiHCO3 aqueous solution from which waste scrap and impurities have been removed; A process including a step 9 of producing a crystallized Li2CO3-containing solution by subjecting a LiHCO3 aqueous solution obtained through a solid-liquid separation process to microwave treatment to crystallize LiHCO3 into Li2CO3; and a step 10 of dehydrating and washing the crystallized Li2CO3-containing solution to obtain Li2CO3 crystals is performed. At least one selected from the dehydrated and washed liquids generated in step 10 is recycled in step 5. A method for recycling lithium carbonate from spent lithium-ion batteries, characterized in that each of the passivation treatment in step 1, the crushing treatment in step 2, the decomposition treatment in step 3, and the heat treatment in step 4 is performed under a gas atmosphere containing N2 and CO2.

14. In paragraph 13, the passivation treatment in step 1, the crushing treatment in step 2, and the decomposition treatment in step 3 are performed in an atmosphere containing O25 volume% or less and the remaining balance of CO2 and N2 among 100 volume%, The heat treatment in the fourth step is performed under a mixed gas of 10 to 30 volume% of carbon precursor and the remaining balance of 100 volume%, wherein the mixed gas is H2, CO2 and A method for recycling lithium carbonate from spent lithium-ion batteries, characterized in that the method comprises N2 in a molar ratio of 0.02 to 0.06: 0.15 to 0.35: 0.41 to 0.87 and is performed under an oxygen-free atmosphere.

15. A method for recycling lithium carbonate from waste lithium-ion batteries, characterized in that the fourth step of heat treatment in paragraph 13 is performed at 600 to 1,150°C for 30 to 360 minutes.

16. In the 15th paragraph, if the shredded material is a shredded material derived from an NCM (lithium nickel manganese) battery, an NCA (ternary lithium) battery, or an LCO (lithium cobalt oxide) battery, the heat treatment is performed at a temperature of 600 to 800°C, A method for recycling lithium carbonate from waste lithium-ion batteries, characterized in that the heat treatment is performed at a temperature of 850 to 1150°C when the shredded material is shredded material from an LMO (lithium manganese nickel oxide) battery or an LFP (lithium iron phosphate) battery.

17. In the 13th paragraph, the separation and selection process of the heat-treated crushed material in the 5th step is as follows: Step 5-1: Air classifying the heat-treated shredded material to obtain shredded material from which shredded material lighter than black mass is removed; Step 5-2, which performs particle size separation on the crushed material from Step 5-1 to obtain black mass from which crushed material heavier than black mass is removed; and A process including step 5-3 of performing magnetic separation on the black mass obtained by performing step 5-2 to obtain black mass containing Li2CO3 from which reduced substances in the black mass are removed is performed, A method for recycling lithium carbonate from spent lithium-ion batteries, characterized in that the heavy shreds of step 5-2 contain at least one metal selected from Co, Ni, Mn, Al, Cu and Fe.

18. In the 13th paragraph, step 6 is to add water, balls for ball mill, and black mass containing Li2CO3 obtained in step 5 to a water leaching reactor, and then add CO2 while performing a water leaching reaction for 30 minutes to 5 hours under conditions of a rotation speed of the water leaching reactor or a stirrer rotation speed of 50 to 400 rpm and a temperature of 0 to 50°C. A method for recycling lithium carbonate from spent lithium-ion batteries, characterized in that water and black mass containing the Li2CO3 are added in a weight ratio of 1:1 to 10.

19. A method for recycling lithium carbonate from a spent lithium-ion battery, characterized in that the 6-step water leaching reaction in claim 18 is performed under conditions in which a pH of 5 to 7 is maintained.

20. In the 13th paragraph, the step 7 is performed by adding a fluoride removal agent and an impurity removal agent to a leaching reactor containing an aqueous solution containing LiHCO3 after 30 minutes from the completion of the leaching reaction, and then performing the process for 30 minutes to 2 hours under conditions of a rotation speed of the leaching reactor or a stirrer rotation speed of 50 to 400 rpm and a temperature of 10 to 50°C. The above fluoride remover is characterized in that it includes at least one selected from Ca(OH)2, CaO, K(OH)2 and K2O, A method for recycling lithium carbonate from spent lithium ion batteries, characterized in that it comprises an impurity remover Na2CO3.

21. In paragraph 13, the 9-step microwave treatment is performed under a vacuum atmosphere and at 40 to 70°C. The experiment was performed by irradiating a LiHCO3 aqueous solution with microwaves of 600 to 1200 W and stirring at a stirring speed of 100 to 400 rpm. A method for recycling lithium carbonate from spent lithium-ion batteries, characterized in that the Li2CO3 crystals of the 10-step process comprise at least 50.0 wt% of plate-shaped crystals.

22. In paragraph 13, the passivation treatment in step 1, the crushing treatment in step 2, and the heat treatment in step 4 are performed under N2 and gaseous CO2. A method for recycling lithium carbonate from waste lithium-ion batteries, characterized in that the above decomposition treatment is performed under conditions in which supercritical CO2 maintains a supercritical state.

23. A lithium carbonate (Li2CO3) crystal from a waste lithium ion battery manufactured by a method selected from any one of claims 13 to 22, High-purity lithium carbonate crystals recycled from waste lithium-ion batteries, characterized in that the lithium carbonate (Li2CO3) crystals have a purity of 99.00 to 99.99% and contain plate-shaped crystals in an amount of 50.0 wt% or more.

24. A cathode material for a lithium-ion secondary battery comprising the recycled lithium carbonate crystal of Article 23.

25. A lithium ion secondary battery comprising the recycled lithium carbonate crystals of Article 23.

Images