Method for recycling positive electrode material for secondary batteries and device for recycling positive electrode material for secondary batteries using the same

Abstract

The present invention provides a method for recycling cathode materials for secondary batteries that can safely separate cathode materials contained in waste batteries without producing by-products such as acidic waste, as well as recycle the rapidly increasing number of waste batteries through a simple and efficient process, thereby significantly reducing social and economic costs.

Description

[Technical Field]

[0001] The present invention relates to a method for recycling a cathode material for a secondary battery, and more particularly, to a method for recycling a cathode material for a secondary battery, which can safely separate cathode materials contained in waste batteries without producing by-products such as acidic waste, and can recycle waste batteries through a simple and efficient process, thereby significantly reducing social and economic costs, and a recycling apparatus for a cathode material for a secondary battery using the same. [Background technology]

[0002] Recently, with the development of the lithium-ion secondary battery industry, the production volume of batteries using these batteries has been increasing exponentially. As a result, the amount of waste batteries that have reached the end of their lifespan is increasing, and it is expected that various social and economic cost issues will arise due to the disposal of waste batteries.

[0003] Furthermore, waste batteries cannot be disposed of like general waste due to fire hazards, toxicity, and metallicity issues, and must be stored and disposed of separately. To safely dispose of such waste batteries, each component must be disassembled and stabilized before disposal, and the component that accounts for the greatest cost is the cathode material, such as LiCoO2, Li(Ni,Co,Al)O2, LiMnO2, and Li(Ni,Co,Mn)O2.

[0004] Therefore, in order to solve the social and economic cost issues of waste battery treatment and recycle the above-mentioned cathode material, research is being conducted on a method of dissolving the entire cathode material in a strong acid solution and then gradually precipitating and separating desired metals by adding additives. However, the following problems have limited the practical application of this method in industry.

[0005] First, metals used in secondary battery cathode materials, such as nickel, cobalt, aluminum, and manganese, have similar chemical properties, making it difficult to separate them into pure substances, and additional purification processes are required to separate them into pure substances. This increases the complexity of the recycling process and increases costs, significantly reducing the efficiency and economic viability of recycling.

[0006] Second, the above method requires an additional purification process not only for the cathode material but also for the Li dissolved in the acid. That is, since Li has better solubility than other metals used in cathode materials, Li is also separated during the separation process of other metals, which can increase the burden on the purification process.

[0007] Thirdly, due to these characteristics of Li, there are difficulties in the process of recycling by further mixing Li precursors and synthesizing them with the same composition as the original material, as Li is contained in the separation process of other metals, requiring an additional purification process to purify it during the resynthesis process.

[0008] Therefore, there is an urgent need to research a simple and efficient recycling method for cathode materials for secondary batteries that can safely disassemble and process the components of waste batteries, reduce social and economic costs through recycling, solve the above-mentioned problem of separation efficiency, and selectively recover cathode materials without requiring additional processes. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made to overcome the above-mentioned problems, and the first problem to be solved by the present invention is to provide a method for recycling cathode materials for secondary batteries and a recycling device using the same, which can reduce social and economic costs associated with the rapidly increasing use of secondary batteries by safely separating and recycling cathode materials contained in waste batteries.

[0010] Another object of the present invention is to provide a simple and efficient method for recycling cathode materials for secondary batteries and a recycling apparatus using the same, which can omit a purification process that is required depending on the chemical properties of the cathode materials in the process of separating the cathode materials contained in waste batteries.

[0011] Furthermore, a third object of the present invention is to provide a method for recycling cathode materials for secondary batteries and a recycling apparatus using the same, which does not use a strong acid in the process of separating cathode materials contained in waste batteries, thereby preventing the generation of additional acidic waste and selectively recovering only Li, thereby improving processing efficiency and economy. [Means for solving the problem]

[0012] In order to solve the above-mentioned problems, the present invention provides: (1) an LMO separated from a battery; X (S100) forming a first mixture by chlorinating a cathode material containing MO with a gas containing chlorine; and (2) contacting the first mixture with a solvent to form MO. x (2) separating MCO3 from the second mixture and forming a second mixture containing a solvent (S200), (3) reacting the second mixture with a carbonate to separate MCO3 (S300), and (4) separating lithium carbonate (Li2CO3) from the second mixture from which MCO3 has been separated (S400). In this case, L is Li (lithium), M is one or more selected from Co (cobalt), Ni (nickel), Al (aluminum), and Mn (manganese), and x is a constant between 0.5 and 2.5.

[0013] According to one embodiment of the present invention, the temperature for the chlorination reaction may be 450 to 700°C.

[0014] According to another embodiment of the present invention, the chlorine-containing gas may be chlorine gas (Cl2).

[0015] According to another embodiment of the present invention, the first mixture in step (1) contains LiCl, MCl y and MO X In this case, y is a constant of 1 to 3.

[0016] According to one embodiment of the present invention, the chlorine gas may be contained in an amount of 10 to 90% by weight based on the total weight of the chlorine-containing gas.

[0017] According to another embodiment of the present invention, the solvent in step (2) may be at least one of water and alcohol.

[0018] According to yet another embodiment of the present invention, the carbonate in step (3) may be any one of sodium carbonate and potassium carbonate.

[0019] According to an embodiment of the present invention, step (4) may be a step of drying the second mixture from which MCO has been separated to partially remove the solvent, and separating lithium carbonate based on the difference in solubility in the solvent.

[0020] According to another embodiment of the present invention, step (4) may further include: (4-1) drying the second mixture from which MCO has been separated to partially or completely remove the solvent (S410); and (4-2) adding a second solvent to separate lithium carbonate and sodium chloride contained in the second mixture using a difference in solubility in the solvent (S420).

[0021] Furthermore, according to one embodiment of the present invention, the MOs separated in the above step can be x , MCO3, LMO using lithium carbonate X The method may further include a step of reproducing (S430).

[0022] The present invention also provides a positive electrode material for a secondary battery that is reproduced by the above-mentioned method for recycling a positive electrode material for a secondary battery.

[0023] The present invention also provides an LMO separated from the battery. X The cathode material containing MO is subjected to a chlorination reaction with a gas containing chlorine. x In this case, L is Li (lithium), M is one or more selected from Co (cobalt), Ni (nickel), Al (aluminum), and Mn (manganese), and x is a constant of 0.5 to 2.5.

[0024] The present invention also provides an LMO separated from the battery. X a first reaction section in which a cathode material containing MO is reacted with a gas containing chlorine to form a first mixture; and a first reaction section in which the first mixture is contacted with a solvent to form MO. x and forming a second mixture containing a solvent, a second separation section communicating with the first separation section and reacting the second mixture with a carbonate to separate MCO3, and a third separation section communicating with the second separation section and separating lithium carbonate from the second mixture from which MCO3 has been separated, wherein L is Li (lithium), O is oxygen, M is one or more selected from Co (cobalt), Ni (nickel), Al (aluminum), and Mn (manganese), and x is a constant between 0.5 and 2.5.

[0025] According to one embodiment of the present invention, the MO separator communicates with the first to third separation sections and separates from the first to third separation sections. x , MCO3 and lithium carbonate to LMO X It may further comprise a synthesis unit that reproduces

[0026] According to another embodiment of the present invention, the first reaction section may further include a gas injector for injecting a gas into the first reaction section.

[0027] According to still another embodiment of the present invention, the first reaction section may further include a heater for maintaining the chlorine-containing gas at a high temperature.

[0028] According to an embodiment of the present invention, the first separation unit may further include a solvent injection unit for injecting a solvent. [Effects of the Invention]

[0029] According to the method for recycling cathode materials for secondary batteries according to the present invention, the cathode materials contained in waste batteries can be safely separated and efficiently recycled, thereby reducing the social and economic costs associated with the rapidly increasing use of secondary batteries.

[0030] In addition, according to the method for recycling cathode materials for secondary batteries according to the present invention, in the process of separating cathode materials contained in waste batteries, it is possible to omit a purification process that is required depending on the chemical properties of the cathode materials, thereby simplifying the overall process and maximizing the efficiency of the separation process.

[0031] Furthermore, according to the method for recycling cathode materials for secondary batteries according to the present invention, since a strong acid is not used in the process of separating cathode materials contained in waste batteries, additional acidic waste is not generated and only Li can be selectively recovered, thereby significantly improving the processing efficiency and economy in not only the separation process but also the resynthesis process. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 is a flow chart that schematically illustrates a method for recycling a positive electrode material for a secondary battery according to one embodiment of the present invention. [Figure 2] FIG. 2 is a flow chart schematically illustrating a method for recycling a cathode material for a secondary battery according to another embodiment of the present invention. [Figure 3a-i] 3a to 3i are graphs showing the results of X-ray diffraction analysis of a used battery positive electrode material that has undergone a chlorination reaction according to an embodiment of the present invention. [Figure 4] FIG. 4 is a photograph showing that brown MCO3 was separated as a precipitate after a chlorination reaction according to one embodiment of the present invention. [Figure 5]FIG. 5 is a photograph showing that the solution from which MOx and MCO3 have been removed according to one embodiment of the present invention is dried under vacuum at 120° C. to completely evaporate the solvent. [Figure 6] FIG. 6 is a graph illustrating the results of the X-ray diffraction experiment analysis of FIG. 5 according to one embodiment of the present invention. [Figure 7] FIG. 7 is a photograph showing the separation of Li2CO3 as a precipitate from a Li2CO3 / NaCl / H2O solution according to one embodiment of the present invention. [Figure 8] FIG. 8 is a graph illustrating the results of the X-ray diffraction experiment analysis of FIG. 7 according to one embodiment of the present invention. [Figure 9] FIG. 9 is a graph showing the results of an X-ray diffraction experiment analysis of Li2CO3 separated from a Li2CO3 / NaCl mixture using methanol according to one embodiment of the present invention. [Figure 10] FIG. 10 is a flow chart showing steps for resynthesizing a cathode material according to one embodiment of the present invention. [Figure 11] FIG. 11 is a graph showing the results of an X-ray diffraction experiment analysis of a sample resynthesized according to one embodiment of the present invention. [Figure 12] FIG. 12 is a graph showing the results of a charge-discharge experiment of a sample resynthesized according to one embodiment of the present invention. [Figure 13] FIG. 13 is a diagram showing a recycling device for secondary battery positive electrode materials according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0033] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention may be embodied in various different forms and is not limited to the embodiments set forth herein.

[0034] As mentioned above, conventional recycling processes for waste batteries have poor separation efficiency, require additional processes, and generate by-products through strong acid treatment, which incurs high social and economic costs, limiting their practical application in industry.

[0035] Therefore, the present invention provides an LMO separated from the battery. X a step (S100) of forming a first mixture by chlorinating a cathode material containing MO with a gas containing chlorine; and contacting the first mixture with a solvent to form MO. x To solve the above-mentioned problems, the present inventors have provided a method for recycling a cathode material for a secondary battery, the method comprising the steps of: separating MCO3 from the cathode material to form a second mixture containing a solvent (S200); reacting the second mixture with a carbonate to separate MCO3 (S300); and separating lithium carbonate (LiCO3) from the second mixture from which MCO3 has been separated (S400).

[0036] This allows the components of waste batteries to be safely disassembled and treated, reducing social and economic costs through recycling, and also solving the aforementioned problem of separation efficiency. This may enable simple and efficient recycling of cathode materials for secondary batteries, allowing selective recovery of cathode materials without the need for additional processes.

[0037] FIG. 1 is a flow chart that schematically shows a method for recycling a cathode material for a secondary battery according to one embodiment of the present invention, and the present invention will be specifically described below with reference to this figure.

[0038] The present invention provides a method for (1) separating LMO from a battery. X The cathode material containing the above is subjected to a chlorination reaction with a gas containing chlorine to form a first mixture (S100).

[0039] In this case, L is Li (lithium), M is one or more selected from Co (cobalt), Ni (nickel), Al (aluminum), and Mn (manganese), and x is a constant of 0.5 to 2.5.

[0040] As mentioned above, a conventional method for recycling cathode materials for secondary batteries involves leaching waste batteries in a strong acid solution to separate lithium and cathode metal materials. However, this separation method using a strong acid not only generates additional acidic waste, but also has problems such as the reactivity of lithium causing it to be separated together with other metals during the separation process, requiring an additional purification process to separate lithium, and significantly reducing separation efficiency due to the similar chemical properties of the metals.

[0041] Therefore, the present invention solves the above-mentioned problems by subjecting a cathode material to a chlorination reaction with a chlorine-containing gas. More specifically, in waste batteries, an oxide in the form of LiMO2, which is a cathode material, may be formed. In the cathode material recycling method according to the present invention, the oxide in the form of LiMO2, which is a cathode material, is converted into lithium and MO through a chlorination reaction carried out in step (1). x That is, lithium can be converted into LiCl, and the cathode metal material M can be separated into MO. x or MCl y However, most M can be separated into oxides of the form MO x The lithium chloride is separated into oxides of various forms and can be recycled as a cathode material for secondary batteries through a separation process described below. Through this, the present invention can simplify the overall process by selectively and easily recovering lithium chloride without generating secondary acidic waste, thereby maximizing treatment and process efficiency.

[0042] In this regard, the chlorination reaction in step (1) may be carried out at a temperature of 450 to 700°C, more preferably at a temperature of 520 to 620°C, and the temperature of the chlorination reaction may be the gas temperature. If the chlorination reaction temperature is less than 450°C, lithium chloride may not be sufficiently formed, which may result in a decrease in the efficiency of separating the waste battery. If the chlorination reaction temperature exceeds 700°C, the produced LiCl may volatilize and disappear due to the excessively high temperature. In addition, the chlorination reaction according to the present invention may be carried out for 1 to 8 hours, more preferably 2 to 6 hours, under the above temperature conditions.

[0043] The amount of the chlorine-containing gas can be appropriately selected depending on the amount of LiMO2, which is the positive electrode material input from the waste battery, and is preferably mixed in an amount of 150 to 1000 parts by weight relative to the total weight of LiMO2. If the chlorine-containing gas is contained in an amount of less than 150 parts by weight relative to the total weight of LiMO2, the desired chlorination reaction will not proceed sufficiently, and LiCl, MO x If the chlorine-containing gas is contained in an amount exceeding 1000 parts by weight based on the total weight of LiMO2, the excessive use of chlorine may increase the process cost.

[0044] In this case, examples of the chlorine-containing gas include Cl2, HCl, COCl2, and CCl4, and Cl2 is preferred. More specifically, the chlorine-containing gas can be a mixture of 5 to 90 wt% chlorine gas with the remaining amount of Ar, N2, O2, or other gases. If the chlorine gas is mixed at less than 5%, the efficiency of the chlorination reaction may decrease, and the lithium-containing cathode material may not be sufficiently separated. If the chlorine gas is mixed at more than 90%, the process efficiency may decrease due to the generation of excessive unreacted chlorine gas. Therefore, the mixing ratio of chlorine gas can be appropriately selected taking into account the type and content of the cathode material from the waste battery.

[0045] 3a to 3i show the experimental results of the temperature and time for separating lithium into LiCl in step (1) of the secondary battery recycling method according to the present invention, where the experiment was carried out at 500°C for 6 hours, 550°C for 4 hours, and 600°C for 2 hours, respectively.

[0046] As shown in Figures 3a-3i, after step (1) of the present invention, the production of chlorides including LiCl is confirmed as peak 2, and after washing, the production of MO is confirmed as peak 4. This shows that the chlorination reaction of the present invention enables selective separation of lithium compared to conventional methods of separating cathode materials and lithium using acid, and further shows that the efficiency of selective separation of lithium is best under the specific temperature and time conditions of the chlorination reaction described above, which will be described in detail in the experimental examples.

[0047] As described above, the method for recycling cathode materials for secondary batteries according to the present invention can replace the conventional strong acid treatment method by using chlorine gas (Cl) in step (1), suppressing the generation of by-products such as acidic waste and enabling the realization of an environmentally friendly separation process. Furthermore, since no further purification process is required, process simplification and cost reduction can be achieved at the same time.

[0048] Next, in the step (2) of the present invention, the first mixture formed in the step (1) is contacted with a solvent to form MO x and forming a second mixture containing the solvent (S200).

[0049] Conventional separation methods using strong acids have the problem of reduced separation efficiency due to the similar chemical properties of the cathode metal materials, i.e., a specific cathode metal material is not separated, but other cathode metal materials with similar properties are separated together, requiring additional metal separation and purification processes, which reduces separation and recycling efficiency.

[0050] Therefore, the present invention provides a method for producing MO that does not undergo a chlorination reaction in the first mixture after the step (1). xMO is produced through a simple process of (2) contacting the x The above-mentioned problem was solved by separating the chlorides. More specifically, the chlorides such as LiCl generated in the step (1) of the chlorination reaction described above are dissolved in the solvent through this step and converted into a liquid, and the MO that does not react with chlorine is separated. x The MO remains in a solid state and can be easily separated by washing with a solvent. x Since the metal material is insoluble in the solvent, it can be selectively separated through a simple process of washing and separating with the solvent, and no further purification process is required.

[0051] In this case, the solvent used in step (2) is MO x Any known substance capable of dissolving chlorides such as LiCl without dissolving other compounds may be used. More preferably, either water or alcohol may be used, taking into consideration the properties and amounts of solvents used in the separation steps in steps (3) and (4) described below. Most preferably, water may be used, which is more advantageous than alcohol in that it has a high solubility for LiCl and can be operated with a relatively small amount.

[0052] The amount of solvent added in step (2) can be appropriately selected taking into consideration the amount of the first mixture transferred in step (1), and preferably, the amount of solvent added is 3,000 to 10,000 parts by weight relative to the total weight of the first mixture transferred in step (1).

[0053] As described above, the method for recycling a cathode material for a secondary battery according to the present invention is to x The present invention can easily separate the above-mentioned compounds, and at the same time, an environmentally friendly separation process can be realized. Since no additional purification process is required, process simplification and cost reduction can be achieved at the same time.

[0054] Next, step (3) of the present invention is a step (S300) of separating MCO3 by reacting the second mixture formed in step (2) with carbonate.

[0055] As described above, the method for recycling a cathode material for a secondary battery according to the present invention has the advantage that the metal substance of the cathode material can be separated without treating it with a strong acid. x After the step of separating the first mixture, i.e., contacting the first mixture with a solvent to separate the MO x The lithium and MCO3 contained in the second mixture can be easily separated through step (3) of separating the lithium and MCO3 from the second mixture to form a second mixture containing a solvent, and then reacting the second mixture with a carbonate to separate MCO3.

[0056] More specifically, in step (3), the second mixture reacts with carbonate to produce lithium carbonate (Li2CO3), MCO3 containing the cathode metal material, and NaCl as products. While the MCO3 that does not dissolve in the solvent precipitates, the lithium carbonate and NaCl dissolved in the solvent remain in aqueous solution, allowing them to be separated to obtain the precipitated solid MCO3. The separated MCO3 can be transferred to the synthesis process and recycled as a transition metal precursor.

[0057] The carbonate to be reacted with the second mixture may be a common carbonate capable of reacting with lithium and the cathode metal material M to form a salt, preferably either sodium carbonate or potassium carbonate, and most preferably sodium carbonate, which may be more advantageous in terms of process cost than using potassium carbonate, which is relatively expensive.

[0058] The amount of carbonate can be appropriately selected taking into consideration the amount of the second mixture formed in step (2), and is preferably 40 to 400 parts by weight based on the total weight of the second mixture formed in step (2). If the carbonate is contained in an amount less than 40 parts by weight based on the total weight of the second mixture, sufficient amounts of lithium carbonate and MCO3 may not be formed, resulting in a problem of reduced separation efficiency. If the carbonate is contained in an amount exceeding 400 parts by weight, the amount of carbonate is too high, and subsequent washing and further purification steps may be required.

[0059] Figure 4 shows the experimental results of step (3), in which sodium carbonate was added to the second mixture containing the solvent and separated in solution from the brown MCO3 precipitate. Referring to Figure 4, MCO3, which has low solubility, precipitates, while lithium carbonate and NaCl, which have relatively high solubility, remain in solution in the solvent.

[0060] As described above, the method for recycling a cathode material for a secondary battery according to the present invention can easily separate MCO3 and Li2CO3 through step (3) to selectively obtain lithium and cathode metal material M, and at the same time, it is possible to realize an environmentally friendly separation process. Since no additional purification process is required, it is possible to simultaneously achieve process simplification and cost reduction.

[0061] Next, step (4) of the present invention is a step (S400) of separating lithium carbonate (Li2CO3) from the second mixture from which MCO3 has been separated in step (3).

[0062] That is, step (4) is a step of selectively recovering lithium by separating Li2CO3 and NaCl dissolved in the solvent in step (3). In particular, the second mixture is dried to partially remove the solvent contained therein, and lithium carbonate and NaCl present in a solution state can be separated from the second mixture due to the difference in solubility in the solvent.

[0063] More specifically, this will be described with reference to FIG.

[0064] Figure 7 shows the separation of lithium carbonate and NaCl from the second mixture. Referring to Figure 7, it can be seen that NaCl, which has a relatively high solubility in the solvent, dissolves in water and exists as an aqueous NaCl solution, while lithium carbonate, which has a relatively low solubility in the solvent, is separated in a solid form. Furthermore, Figure 8, which shows the results of an X-ray diffraction experiment, reveals that the recovered Li2CO3 precipitate was separated into a highly pure material containing only a trace amount of NaCl.

[0065] As shown in FIG. 2, in one embodiment of the method for recycling a cathode material for a secondary battery according to the present invention, step (4) may further include step (4-1) of drying the second mixture from which MCO3 has been separated to remove part or all of the solvent (S410).

[0066] In another embodiment of the method for recycling a cathode material for a secondary battery according to the present invention, step (4) may be replaced with step (4-2) in which the solvent contained in the second mixture formed in step (4) is completely dried, a second solvent is further added to separate lithium carbonate and NaCl, and step (S420) may be performed using the difference in solubility in the second solvent.

[0067] In this case, the second solvent for separating lithium carbonate and NaCl may be a common solvent that can dissolve NaCl without dissolving lithium carbonate, and preferably water, alcohol, ammonia, or the like may be used, and most preferably water or methanol may be used. In this case, since there is a large difference in solubility between lithium carbonate and NaCl, it may be advantageous in that high-purity lithium carbonate can be easily separated.

[0068] The amount of the solvent used may be appropriately selected in consideration of the amounts of lithium carbonate and NaCl contained in the second mixture, and more preferably, the solvent may be further added in an amount of 100 to 50,000 parts by weight based on the total parts by weight of the second mixture transferred to step (4).

[0069] In this case, the drying process may be carried out at a temperature of 20 to 200° C., more preferably at a temperature of 50 to 150° C. under vacuum conditions, which may be appropriately selected in consideration of the type and properties of the solvent contained in the second mixture.

[0070] FIG. 5 shows the state after the chloride-containing solution is dried under vacuum at 120°C and the solvent is completely evaporated according to step (4-1) of the present invention. Referring to FIG. 5, it can be seen that both lithium carbonate and NaCl are separated into solid powders. Furthermore, the X-ray diffraction experiment results of FIG. 6 show that pure lithium carbonate and NaCl are separated, since no peaks other than those for lithium carbonate and NaCl are observed. Subsequently, lithium carbonate and NaCl can be separated based on their difference in solubility after adding the second solvent in step (4-2) described above. For example, the X-ray diffraction experiment results of FIG. 9 show that lithium carbonate separated using methanol is separated into pure lithium carbonate, with no other substances observed. The lithium carbonate separated by this process can be transferred to a synthesis process and recycled as a transition metal precursor.

[0071] As described above, the method for recycling a cathode material for a secondary battery according to the present invention can easily separate lithium carbonate and NaCl through step (4) to selectively obtain lithium, and at the same time, it is possible to realize an environmentally friendly separation process. Since no additional purification process is required, it is possible to simultaneously achieve process simplification and cost reduction.

[0072] 10, the method for recycling a cathode material for a secondary battery according to the present invention may further include, as step (4-3), a step (S430) of regenerating the cathode material separated through the above steps to regenerate the cathode material for a secondary battery. x , MCO3, and lithium carbonate can be resynthesized to regenerate the cathode material for secondary batteries, and if necessary, further lithium carbonate can be added to regenerate the desired amount of LMO2.

[0073] More specifically, the description will be made with reference to FIGS.

[0074] Figure 11 shows the MOs separated in the above steps. x 11 shows the results of X-ray diffraction analysis of a synthesized sample in which a certain amount of lithium carbonate was further added to MCO3 and lithium carbonate, mixed, and then heat-treated to perform a resynthesis process. Referring to FIG. 11, it can be seen that the synthesized sample had the same phase as the original Li(Ni,Co,Mn)O2 phase, indicating that the cathode material separated by decomposition from waste batteries was recycled.

[0075] FIG. 12 shows a charge / discharge experiment conducted after manufacturing a secondary battery using the resynthesized sample. Referring to the same figure, the secondary battery manufactured using the resynthesized sample exhibits a value of 105 mAh / g, which is approximately 90% of the initial charge capacity of 120 mAh / g. This shows that the secondary battery manufactured using the resynthesized sample according to the present invention also exhibits stable charge / discharge operation and high recycling efficiency.

[0076] As described above, the method for recycling the cathode material for secondary batteries according to the present invention is to recycle the LMO separated from the battery. X The cathode material containing MO is subjected to a chlorination reaction with a gas containing chlorine. x wherein L is Li (lithium), M is at least one selected from Co (cobalt), Ni (nickel), Al (aluminum), and Mn (manganese), and x is a constant between 0.5 and 2.5.

[0077] This allows for safe separation and efficient recycling of cathode materials contained in waste batteries, thereby reducing the social and economic costs associated with the rapidly increasing use of secondary batteries.In addition, in the process of separating cathode materials contained in waste batteries, it is possible to omit the refining process that was previously required due to the chemical properties of the cathode materials, thereby simplifying the overall process and maximizing the efficiency of the separation process.

[0078] Furthermore, according to the method for recycling cathode materials for secondary batteries according to the present invention, since a strong acid is not used in the process of separating cathode materials contained in waste batteries, additional acidic waste is not generated and only Li can be selectively recovered, thereby significantly improving the processing efficiency and economy in not only the separation process but also the resynthesis process.

[0079] The present invention also provides a recycling apparatus for a cathode material for a secondary battery that embodies the above-described method for recycling a cathode material for a secondary battery, and a cathode material for a secondary battery embodied therethrough. Hereinafter, the recycling apparatus for a cathode material for a secondary battery that embodies the method for recycling a cathode material for a secondary battery according to the present invention will be described. To avoid redundancy, the same description as for the method for recycling a cathode material for a secondary battery will be omitted.

[0080] This invention uses LMO separated from the battery. X a first reaction section in which a cathode material containing MO is reacted with a gas containing chlorine to form a first mixture; and a first reaction section in which the first mixture is contacted with a solvent to form MO. x and forming a second mixture containing a solvent, a second separation section communicating with the first separation section and reacting the second mixture with a carbonate to separate MCO3, and a third separation section communicating with the second separation section and separating lithium carbonate from the second mixture from which MCO3 has been separated, wherein L is Li (lithium), O is oxygen, M is one or more selected from Co (cobalt), Ni (nickel), Al (aluminum), and Mn (manganese), and x is a constant between 0.5 and 2.5.

[0081] FIG. 13 is a diagram showing a recycling apparatus for a cathode material for a secondary battery for implementing the method for recycling a cathode material for a secondary battery according to the present invention, and will be described below with reference to FIG.

[0082] In the first reaction section 110, MO xand a chlorination reaction is carried out to separate the chloride.

[0083] More specifically, in the first reaction section 110, LMO separated from the battery X The cathode material containing MO is subjected to a chlorination reaction with a gas containing chlorine. x and chlorides. X The lithium can be obtained by converting it into LiCl, and the metal material of the positive electrode, M, can be MO. x or MCl y The oxides may be separated into various forms.

[0084] Accordingly, the first reaction unit 110 may further include a separate gas injection unit (not shown) for injecting the chlorine-containing gas. X Since the reactant reacts with the gas under high temperature conditions, a heater (not shown) may be further included to maintain the high temperature. The shape and material of the injection port and heater are not particularly limited and may be any conventional material as long as they are suitable for the purpose of the present invention.

[0085] Next, the first separation unit 120 communicates with the first reaction unit 110 and contacts the first mixture with a solvent to produce MO x is separated to form a second mixture that includes the solvent.

[0086] More specifically, the first mixture formed in the first reaction unit 110 may be transferred to the first separation unit 120 via a transfer path (not shown). The transferred first mixture comes into contact with a solvent, and chlorides such as LiCl are dissolved in the solvent and converted into a liquid state. MOs that do not react with chlorine are separated. x remains in a solid state and can be easily separated by washing through a solvent.

[0087] Accordingly, the first separation unit 120 may further include a solvent injection unit (not shown) for injecting a solvent, and the shape and material of such an injection unit are not particularly limited as long as they are consistent with the object of the present invention.

[0088] Next, the second separation unit 130 communicates with the first separation unit 120, and reacts the second mixture with carbonate to separate MCO3.

[0089] More specifically, the second mixture containing chlorides such as LiCl dissolved in a solvent and present in a liquid state in the first separation unit 120 may be transferred to the second separation unit 130 through a transfer path (not shown), and the transferred second mixture may react with carbonate to separate and obtain lithium carbonate (LiCO) containing lithium and MCO containing a cathode metal material as products.

[0090] Accordingly, the second separation unit 130 may be provided with carbonate in advance to react with the second mixture transferred to the first separation unit 120, but is not limited thereto, and carbonate may be injected through an additional injection unit (not shown).

[0091] Next, the third separation unit 140 communicates with the second separation unit 130 and separates lithium carbonate from the second mixture from which MCO3 has been separated.

[0092] More specifically, the third separation unit 140 may separate lithium carbonate and NaCl dissolved in the solvent as the second mixture to selectively recover lithium. In particular, the second mixture containing the solvent may be dried to remove the solvent partially or completely, and lithium carbonate and NaCl present in a solution state in the second mixture may be separated based on the difference in solubility in the solvent.

[0093] Accordingly, the third separation unit 140 may further include a solvent injection unit (not shown) for injecting a solvent, and the shape and material of such an injection unit are not particularly limited as long as they are consistent with the object of the present invention.

[0094] Next, the recycling apparatus for secondary battery cathode material according to the present invention is connected to the first separation section 120, the second separation section 130 and the third separation section 140, and is configured to recycle the MO separated from the first separation section 120, the second separation section 130 and the third separation section 140. x, MCO3 and lithium carbonate to LMO X The signal may further include a synthesis unit 150 for reproducing the signal.

[0095] That is, the cathode material MO separated in each of the above-mentioned separation sections x , MCO, and lithium carbonate can be used to regenerate the cathode material for secondary batteries through a conventional resynthesis process, and if necessary, lithium carbonate can be added to regenerate the desired amount of LMO2.

[0096] The present invention will be described in more detail below with reference to examples. However, it should be understood that the following examples do not limit the scope of the present invention, but are merely intended to aid in the understanding of the present invention. [Example]

[0097] (1) the chlorination step and (2) MO x Separation stage A sample of 1.0 g of a positive electrode material, Li(Ni, Co, Mn)O2, which contains nickel, cobalt, and manganese in a 1:1:1 ratio and was separated from a waste secondary battery, was prepared.

[0098] Next, 1.0 g of the prepared sample was subjected to argon gas at 95 mL / min and chlorine gas at 5 mL / min at different temperatures and times as shown in Table 1 below, and the weight change of the reaction product was measured.

[0099] [Table 1]

[0100] Referring to Table 1, it can be seen that as the reaction progressed, the weight increased because the oxygen site with an atomic weight of 16 was replaced with the heavier chlorine with an atomic weight of 35, confirming that the produced chloride did not volatilize. The phenomenon in which the rate of weight increase decreased as the reaction time increased at each temperature indicates that lithium was converted to chloride quickly in the early stages, and the chlorination reaction of the transition metal then proceeded slowly.

[0101] This shows that the method for recycling a cathode material for a secondary battery according to the present invention allows selective separation of lithium.

[0102] In addition, the X-ray diffraction experiment results for 1.0 g of the sample prepared in this example, which was reacted at 500°C for 6 hours under conditions of 95 mL / min argon gas and 5 mL / min chlorine gas, are shown in Figure 3b. After washing, the X-ray diffraction experiment results are shown in Figure 3c. After reacting at 550°C for 4 hours, the X-ray diffraction experiment results are shown in Figure 3d. After washing, the X-ray diffraction experiment results are shown in Figure 3e. After reacting at 600°C for 2 hours, the X-ray diffraction experiment results are shown in Figure 3f. After washing, the X-ray diffraction experiment results are shown in Figure 3g. The X-ray diffraction experiment results for the sample before reaction under the above gas conditions are shown in Figure 3a. 250 mL of water was used for washing.

[0103] 3a to 3g, the X-ray diffraction analysis results showed that the samples reacted at 550°C and 600°C were converted to the M3O4 form after washing, while the sample reacted at 500°C maintained the initial sample phase. This confirmed that Li was converted to LiCl through the chlorination reaction under the optimal conditions of 550°C and 600°C, making selective separation possible.

[0104] The amount of cathode material was increased to 2.0 g, and the reaction was carried out at 550°C for 4 hours under conditions of 180 mL / min argon gas and 20 mL / min chlorine gas. The results of the X-ray diffraction experiment are shown in Figure 3h, and the results of the X-ray diffraction experiment after cleaning are shown in Figure 3i. In this case, too, the conversion of the M3O4 form was confirmed, confirming that the chlorination reaction is possible under various conditions.

[0105] From this, it can be seen that the method for recycling a cathode material for a secondary battery according to the present invention allows not only selective separation of lithium but also selective separation of metal materials of the cathode material.

[0106] (3) MCO3 separation stage 2 g of the sample that had been subjected to the chlorination reaction in steps (1) and (2) was mixed with 250 mL of water, and MO x Na2CO3 (1.43 g) was added to the separated aqueous solution to conduct an MCO3 precipitation experiment, and the results are shown in Figure 4. Referring to Figure 4, it can be seen that a brown MCO3 precipitate was formed, which indicates that the method for recycling a cathode material for secondary batteries according to the present invention allows selective separation of metallic materials from the cathode material.

[0107] (4) Li2CO3 separation stage Next, 250 mL of the Li2CO3 / NaCl / H2O solution from which the MCO3 precipitate was separated in step (3) was thoroughly dried under vacuum at 120°C to separate Li2CO3 / NaCl from which all the water had evaporated, as shown in Figure 5.

[0108] Subsequently, X-ray diffraction experiments were carried out on the separated Li2CO3 / NaCl, and the results are shown in Figure 6.

[0109] 5 and 6, it can be seen that Li2CO3 and NaCl were separated from the Li2CO3 / NaCl / H2O solution, and no other phases were formed other than Li2CO3 and NaCl. From these results, it can be seen that the method for recycling a cathode material for a secondary battery according to the present invention enables not only selective separation of lithium but also independent and selective separation of different metallic materials of the cathode material.

[0110] (4-1) and (4-2) Li2CO3 separation steps In step (4), 3.38 g of water was added to 1.99 g of Li2CO3 / NaCl from which all the water had evaporated, according to the solubility of NaCl, and a separation process was carried out. The results are shown in FIG.

[0111] Subsequently, X-ray diffraction experiments were carried out on the separated Li2CO3, and the results are shown in Figure 8.

[0112] The same water was evaporated from 1.99 g of Li2CO3 / NaCl, and 150 g of methanol was added to the mixture to carry out the separation process. The X-ray diffraction experiment results of the recovered Li2CO3 are shown in FIG.

[0113] Referring to FIGS. 8 and 9, it can be seen that the method for recycling a cathode material for a secondary battery according to the present invention enables not only selective separation of lithium but also independent and selective separation of different cathode material metal materials, as a result of separation of high-purity LiCO from a LiCO / NaCl / H0 solution.

[0114] (4-3) Re-synthesis stage In Experimental Example 1, MO separated without reacting with chlorine x (1.388 g), MCO3 (0.273 g) isolated in Experimental Example 3, and Li2CO3 (0.708 g) isolated in Experimental Examples 5 and 6 were mixed with Li2CO3 (0.211 g) and then heat-treated at 900°C in air for 3 hours to resynthesize LMO2.

[0115] Thereafter, X-ray diffraction experiments of the resynthesized LMO2 were carried out, and the results are shown in Figure 11. Referring to Figure 11, it can be seen that a phase identical to the initial LMO2 phase was formed.

[0116] Therefore, it can be seen that the method for recycling a cathode material for a secondary battery according to the present invention can efficiently recycle a cathode material for a secondary battery through a simple process.

[0117] Experimental example: Charge / discharge experiment of resynthesized sample A battery was fabricated using the resynthesized LMO2, and charge / discharge experiments were performed. To fabricate electrodes for evaluating electrochemical properties, a slurry was prepared by mixing the resynthesized LMO2, PVDF (polyvinylidene florudie) binder, and conductive carbon in an NMP (n-methyl-2-pyrrolidone) solvent in a mass ratio of 8:1:1. The slurry was then coated onto aluminum foil and dried in a vacuum oven to remove the NMP, completing the electrode fabrication.

[0118] A CR2032 coin cell was fabricated using the electrode as the positive electrode, lithium metal as the negative electrode, 1M LiPF6 in EC / DMC (ethylene carbonate / dimetnyl carbonate) as the electrolyte, and a glass fiber membrane as the separator. The coin cell was cycled in CCCV (constant current-constant voltage) mode at a constant current of 20 mA / g in the voltage range of 2.5 to 4.3 V using a battery cycler. When the charging voltage reached 4.3 V, the constant voltage of 4.3 V was maintained for an additional 20 minutes to ensure sufficient charge capacity. The results are shown in Figure 12.

[0119] Referring to FIG. 12, it was confirmed that the initial charge capacity was approximately 120 mAh / g, and thereafter, the charge / discharge operation proceeded stably at a level of approximately 105 mAh / g.

[0120] This confirmed that the process proposed in the present invention allows recycling of NCM cathode material, and that the final synthesized amount is 90% of the amount initially used in the reaction, confirming that the process proposed in the present invention is simple and highly efficient.

Claims

1. (1) LMO separated from the battery ｘ A step (S100) of forming a first mixture by chlorinating the cathode material containing the above with a gas containing chlorine; (2) contacting the first mixture with a solvent to form MO ｘ (S200) separating the above-mentioned components to form a second mixture containing a solvent; (3) reacting the second mixture with a carbonate to form MCO ３ (S300) separating the (4) The MCO ３ Lithium carbonate (Li ２ CO ３ (S400) separating the The temperature for the chlorination reaction is 450 to 700°C, The solvent in step (2) is at least one of water and alcohol; wherein L is Li (lithium), M is one or more selected from Co (cobalt), Ni (nickel), Al (aluminum), and Mn (manganese), and x is a constant greater than 0.5 and less than or equal to 2.

5.

2. The chlorine-containing gas is chlorine gas (Cl ２ 2. The method for recycling a positive electrode material for a secondary battery according to claim 1, wherein the positive electrode material is a recycled material.

3. In the step (1), the first mixture is LiCl, MCl ｙ and M.O. ｘ Including, 2. The method for recycling a positive electrode material for a secondary battery according to claim 1, wherein y is a constant of 1 to 3.

4. 3. The method for recycling a cathode material for a secondary battery according to claim 2, wherein the chlorine gas is contained in an amount of 5 to 90% by weight based on the total weight of the chlorine-containing gas.

5. 2. The method of claim 1, wherein the carbonate in step (3) is one of sodium carbonate and potassium carbonate.

6. The step (4) is MCO ３ 2. The method for recycling a cathode material for a secondary battery according to claim 1, further comprising the step of drying the separated second mixture, partially removing the solvent, and separating lithium carbonate based on a difference in solubility in the solvent.

7. The step (4) is (4-1) MCO ３ (S410) drying the separated second mixture to remove part or all of the solvent; (4-2) The method for recycling a cathode material for a secondary battery according to claim 1, further comprising: (S420) adding a second solvent to separate lithium carbonate and sodium chloride contained in the second mixture using a difference in solubility in the solvent.

8. (4-3) Separated MO ｘ , MCO ３ , LMO using lithium carbonate ｘ The method of claim 1, further comprising the step of reproducing (S430).

9. A positive electrode material for a secondary battery remanufactured by the method for recycling a positive electrode material for a secondary battery according to claim 1.

10. LMO separated from the battery ｘ a first reaction section that causes a chlorination reaction between the cathode material containing the compound and a gas containing chlorine to form a first mixture; A mixture is in communication with the first reaction section, and the first mixture is contacted with a solvent to form MO ｘ a first separation section that separates the solvent from the first mixture to form a second mixture that includes the solvent; a separator communicating with the first separation section, the separator reacting the second mixture with a carbonate to produce MCO ３ a second separation unit that separates the The MCO is in communication with the second separation section. ３ a third separation section that separates lithium carbonate from the second mixture from which the lithium carbonate has been separated, The temperature for the chlorination reaction is 450 to 700°C, the solvent is at least one of water and alcohol; wherein L is Li (lithium), O is oxygen, M is one or more selected from Co (cobalt), Ni (nickel), Al (aluminum), and Mn (manganese), and x is a constant greater than 0.5 and less than or equal to 2.

5.

11. MO that is in communication with the first separation section, the second separation section, and the third separation section and is separated from the first separation section, the second separation section, and the third separation section ｘ , MCO ３ and lithium carbonate to LMO Ｘ The recycling device for a positive electrode material for a secondary battery according to claim 10, further comprising a synthesis unit for reproducing the positive electrode material for a secondary battery.

12. 11. The recycling apparatus for a cathode material for a secondary battery according to claim 10, wherein the first reaction unit further comprises a gas injector for injecting a gas into the first reaction unit.

13. 11. The recycling apparatus for a cathode material for a secondary battery according to claim 10, wherein the first reaction unit further comprises a heater for maintaining the chlorine-containing gas at a high temperature.

14. The recycling apparatus for a cathode material for a secondary battery according to claim 10, wherein the first separating unit further comprises a solvent injecting unit for injecting a solvent.

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