Method for preparing regenerated positive active material using waste secondary battery

Abstract

The present invention relates to a method for producing a regenerated positive electrode active material, comprising: (S1) a step of generating Co x O y from a positive electrode plate separated from a waste secondary battery through heat treatment; (S2) a step of mixing a substance containing lithium into the generated Co x O y ; (S3) a step of forming a regenerated positive electrode active material from the mixed substance through heat treatment, wherein x and y each have a value between 0 and 10. x O y ​

Description

Technical Field

[0001] This invention relates to a method for preparing regenerated positive electrode active material from waste secondary batteries, and more specifically, to a method for preparing regenerated positive electrode active material that can be regenerated at a high generation rate and provides an efficiency similar to that of the original secondary battery. Background Technology

[0002] With the increasing technological development and demand for mobile devices, the demand for secondary batteries as an energy source is also increasing dramatically. Lithium-ion secondary batteries, characterized by high energy density and voltage, long cycle life, and low self-discharge rate, have been commercialized and are currently widely used.

[0003] The positive electrode active material of lithium-ion batteries uses lithium transition metal oxides, primarily lithium cobalt oxide (LiCoO2), lithium manganese oxide (LiMnO2, LiMn2O4, etc.), lithium iron phosphate compounds (LiFePO4, etc.), and lithium nickel oxide (LiNiO2, etc.). However, the cost of these positive electrode active materials, such as the transition metals that form lithium cobalt oxide or NCM-based lithium oxides, is very high. Cobalt, in particular, is a strategic metal, and its supply and demand are closely monitored by countries worldwide. Due to the limited quantity produced by cobalt-producing countries, it is globally known that cobalt is a metal with unstable supply and demand. Furthermore, these transition metals may cause environmental problems, thus requiring environmental regulations.

[0004] Existing methods for reusing waste lithium-ion batteries involve selectively concentrating the waste positive electrode active material through processes such as crushing, magnetic separation, and grading, followed by cobalt leaching using sulfuric acid with hydrogen peroxide as a reducing agent. To recover cobalt from the leaching solution, further steps are taken, including selective separation and recovery of cobalt using oxalic acid, pH adjustment, and impurity removal. Finally, cobalt sulfate is prepared using solvent extraction for reuse. However, this existing method is limited to lithium cobalt oxide (LCO) in the waste positive electrode active material. For lithium nickel cobalt manganese oxide (NCM) or lithium-ion manganese oxide (LMO) used in electric vehicles, which are increasingly being used, sulfuric acid alone is insufficient for effective leaching. Furthermore, in the existing recycling method, the process of generating cobalt using oxalic acid involves calcination and decomposition of the oxalic acid using carbon dioxide, followed by dissolving the cobalt oxide in sulfuric acid to obtain cobalt sulfate. Therefore, from a cost perspective, this is not a preferred method. Furthermore, the existing recycling methods involve adding excessive amounts of oxalic acid to selectively separate cobalt, which creates considerable difficulties for wastewater treatment.

[0005] Another existing technology involves leaching aluminum-removing positive electrode active material powder with acid, followed by alkaline precipitation to reuse it as a hydroxide mixed with nickel, cobalt, and manganese, or as a single hydroxide. However, the positive electrode active material regenerated in this way has a high impurity content when used as a high-value-added secondary battery precursor, thus lacking value as a complete material and having insufficient commercial viability.

[0006] Therefore, in order to solve the aforementioned problems, the inventors recognized the urgent need to develop an effective method for regenerating the positive electrode active material of secondary batteries, and thus completed this invention.

[0007] [Prior Technology Documents]

[0008] (Patent Document 1) Korean Patent Registration No. 10-2064668

[0009] (Patent Document 2) Japanese Patent Publication No. 1999-006020 Summary of the Invention

[0010] The technical problem to be solved

[0011] The purpose of this invention is to provide a method for preparing regenerated positive electrode active material, which can be easily regenerated from waste secondary batteries, ensures economic efficiency, and provides excellent electrochemical properties.

[0012] The technical problem to be solved by the invention is not limited to the technical problems mentioned above. Other technical problems not mentioned above can also be clearly understood by those skilled in the art through the description of the present invention.

[0013] Technical solutions to solve technical problems

[0014] To achieve the aforementioned objective, the present invention provides a method for preparing regenerated positive electrode active material from waste secondary batteries.

[0015] The preparation method of the regenerated positive electrode active material according to the present invention will now be described in detail.

[0016] The method for preparing the regenerated positive electrode active material of the present invention includes the following steps:

[0017] (S1): The positive electrode plate separated from the waste secondary battery is heat-treated to generate Co. x O y The steps of material;

[0018] (S2): To the generated Co x O y The steps of mixing lithium-containing substances into a material;

[0019] (S3): The step of heat-treating the mixed substances to form a regenerated positive electrode active material.

[0020] In the Co x O y In the equation, x and y have values ​​between 0 and 10.

[0021] In this invention, the positive electrode plate separated from the waste secondary battery in step (S1) may contain active material, conductive material and adhesive.

[0022] In this invention, the heat treatment in step (S1) can be performed in an inert gas or reducing gas environment.

[0023] In this invention, the heat treatment in step (S1) is performed within a temperature range of 510°C to 750°C. The positive electrode plate is reduced by the heat treatment performed in step (S1), thereby generating Co. x O y substance.

[0024] In this invention, the Co generated in step (S1) x O y It includes one or more substances selected from the group consisting of CoO, Co2O3 and Co3O4.

[0025] In this invention, the Co generated in step (S1) x O y The substance is CoO.

[0026] In this invention, the Co generated in step (S1) x O y The material forms a porous structure.

[0027] In this invention, the Co generated in step (S1) x O y The substance contains particles ranging from 0.001 to 10.0 cm. 3 Pores in the range of / g.

[0028] In this invention, the Co generated in step (S1) x O y The substance has a diameter of 0.3 to 50.0 m. 2 Specific surface area per g.

[0029] In this invention, the lithium-containing substance mixed in step (S2) comprises one or more substances selected from the group consisting of LiOH, Li2CO3, LiNO3 and Li3PO4.

[0030] In this invention, the lithium-containing substance mixed in step (S2) is intended to target the Co generated in step (S1). x O y The substance contains a mixture of Co and lithium in a molar ratio of 1.0 to 1.06.

[0031] In this invention, the heat treatment in step (S3) can be performed in a temperature range of 800°C to 1,050°C.

[0032] In this invention, the heat treatment in step (S3) can be performed by dry heat treatment or wet heat treatment.

[0033] In addition, the present invention provides a regenerated positive electrode active material formed according to the aforementioned preparation method.

[0034] All the above-mentioned matters are equally applicable to the method for preparing regenerated positive electrode active material using the waste secondary battery and the regenerated positive electrode active material prepared by this method, provided that they are not contradictory.

[0035] Invention Effects

[0036] The method for preparing regenerated positive electrode active material from waste secondary batteries using the present invention can ensure economic efficiency and ease of regenerating positive electrode active material from waste secondary batteries. At the same time, the electrochemical performance of the positive electrode active material is not reduced during the regeneration process, and it can exhibit excellent impedance characteristics, conductivity characteristics and capacity characteristics.

[0037] The effects of the present invention are not limited to those mentioned above. Other effects not mentioned above can be clearly understood by those skilled in the art through the description in the claims. Attached Figure Description

[0038] Figure 1 This is a block diagram that roughly illustrates the method for preparing the regenerated positive electrode active material from the waste secondary battery of the present invention.

[0039] Figure 2 This is an X-ray photoelectron spectroscopy (XPS) spectrum used to analyze the composition of the positive electrode plate that can be used in the preparation method of the regenerated positive electrode active material of the present invention.

[0040] Figure 3 It is a scanning electron microscope (SEM) image showing the pores formed on the CoO generated in Embodiment 1 of the present invention.

[0041] Figure 4This shows the X-ray diffraction (XRD) pattern of the material prepared by performing step (S1) in an air and (b) argon atmosphere in the method for preparing regenerated positive electrode active material from waste secondary batteries of the present invention.

[0042] Figure 5 This shows the X-ray diffraction (XRD) patterns of the material prepared by heat treatment in step (S1) at 500°C, 600°C and 700°C in the preparation method of the regenerated positive electrode active material of the waste secondary battery of the present invention.

[0043] Figure 6 This is an X-ray diffraction (XRD) pattern showing the CoO generated in Example 1 of the present invention and the regenerated positive electrode active material ((LCO)1) prepared using this CoO.

[0044] Figure 7 It is a graph showing the electrochemical performance of the regenerated positive electrode active material prepared according to the present invention and commonly used positive electrode active materials evaluated using 3.0 to 4.3 V. Detailed Implementation

[0045] While taking into account the functionality of this invention, the terminology used in this specification has been selected as widely used general terms as possible. However, these may change due to factors such as the intent of those skilled in the art, precedents, and the emergence of new technologies. Furthermore, in specific cases, there may be terms arbitrarily chosen by the inventors; in such cases, their meanings will be explained in detail in the description of the corresponding invention. Therefore, the terminology used in this invention is not defined simply by its name, but should be defined based on the meaning of the term and the overall content of the invention.

[0046] Unless otherwise defined, all terms used herein, including technical or scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms having the same meaning as defined in commonly used dictionaries shall be interpreted in accordance with their meaning in the context of the relevant art. Unless otherwise expressly defined in this invention, they shall not be interpreted in an ideal or overly formal sense.

[0047] The numerical range includes the values ​​defined within the range. All the largest numerical limits given in this specification are as if explicitly stated as smaller numerical limits, encompassing all lower numerical limits. All the smallest numerical limits given in this specification are as if explicitly stated as higher numerical limits, encompassing all higher numerical limits. All numerical limits given in this specification are as if explicitly stated as narrower numerical limits, encompassing all better numerical ranges within a wider numerical range.

[0048] Although embodiments of the present invention are described in detail below, it is clear that the present invention is not limited to the embodiments described below.

[0049] The method for preparing regenerated positive electrode active material according to the present invention

[0050] This invention provides a method for preparing a regenerated positive electrode active material, including the following steps.

[0051] (S1) The positive electrode plate separated from the waste secondary battery is heat-treated to generate Co. x O y The steps of material;

[0052] (S2) To the generated Co x O y The steps of mixing a substance containing lithium into a material;

[0053] (S3) The step of heat-treating the mixed substances to form a regenerated positive electrode active material.

[0054] In the Co x O y In this context, x and y can have values ​​from 0 to 10.

[0055] "Positive electrode active material" is the main component in a secondary battery that generates electricity through a chemical reaction, and generally refers to an active material containing lithium oxide. If the positive electrode active material is used in this invention, the positive electrode active material is a positive electrode active material containing lithium and cobalt. Preferably, it can be one or more selected from the group consisting of a layered positive electrode active material with a structure formed by LCO (LiCoO2), LCA (LiCoAlO2), LCM (LiCoMnO2) and LCMA (LiCoMnAlO2), a positive electrode active material with a spinel structure of LMO (LiMn2O4), and a positive electrode active material with a olivine structure of LFP (LiFePO4). Preferably, it can be one or more layered positive electrode active materials selected from the group consisting of LCO, LCA, LCM, and LCMA.

[0056] The LCO is a layered structure of lithium and cobalt oxides, which has the advantages of very high stability and very long lifespan.

[0057] The LCA is a layered structure of lithium, cobalt, and aluminum oxides, which reduces the content of expensive cobalt and has the advantages of easy industrial application and long life.

[0058] The LCM is a layered structure of lithium, cobalt, and manganese oxides, which reduces the content of expensive cobalt and has the advantages of easy industrial application and high stability.

[0059] The LCMA is a layered structure of lithium, cobalt, manganese and aluminum oxides, which can be considered a combination of LCA and LCM, and thus can simultaneously embody the advantages of LCA and LCM.

[0060] The LMO is a spinel-structured lithium and manganese oxide with very high stability. It does not contain expensive cobalt, thus making it very inexpensive.

[0061] The LFP, a olivine-structured substance containing lithium, iron, phosphorus, and oxygen, exhibits the highest stability and longest lifespan compared to LCO (LiCoO2), LCA (LiCoMnO2), LCM (LiCoMnO2), and LMO (LiMn2O4), making it suitable for various applications.

[0062] Step (S1) involves reducing the positive electrode plate separated from the waste secondary battery through heat treatment to generate Co. x O y The steps.

[0063] The positive electrode plate separated from the waste secondary battery used in step (S1) comprises: positive electrode active material, conductive material, adhesive, etc. That is, the positive electrode plate separated from the waste secondary battery used in step (S1) can be used directly while still in the state used in the secondary battery (i.e., in the state where active material, conductive material, adhesive, etc. are coated on the electrode plate and then repressed). When this positive electrode plate is heat-treated in step (S1), Co can be generated because conductive material and adhesive are attached to the positive electrode plate. x O y substance.

[0064] The adhesive is a component that facilitates the bonding of the positive electrode active material with the conductive material and the current collector. Examples of such adhesives include one or more selected from the group consisting of polyvinylidene fluoride (PVDF), polyvinyl alcohol (PVOH, PVA, PVAI), carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose (HPMC), polyvinyl pyrrolidone, polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PP), ethylene-propylene-diene terpolymers (EPDM), styrene-butadiene rubber, fluororubber, and various copolymers. However, there are no restrictions on the use of any commonly used adhesive.

[0065] The conductive material can be any material that is conductive without inducing a chemical change in the secondary battery. Examples include: natural or artificial graphite; carbon black such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and Summer Black; conductive fibers such as carbon fiber or metal fiber; metal powders such as fluorinated carbon, aluminum, and nickel powder; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives.

[0066] Preferably, the heat treatment in step (S1) can be performed on the positive electrode plate within a temperature range of 510°C to 750°C, and most preferably, within a temperature range of 550°C to 660°C. If the heat treatment in step (S1) is performed within a temperature range of less than 510°C, sufficient reduction may not be achieved, and thus the initial active material phase may be preserved.

[0067] Step (S1) can be performed in an environment where the reduction reaction is more easily carried out due to the absence of oxygen. Preferably, it can be performed in an inert gas environment or a reducing gas environment. More preferably, it can be performed in an argon (Ar), nitrogen (N2), carbon dioxide (CO2), carbon monoxide (CO), or hydrogen (H2) environment. Most preferably, it can be performed in an argon or nitrogen environment.

[0068] The Co generated in step (S1) x O y The substance comprises one or more substances selected from the group consisting of CoO, Co2O3, and Co3O4. Preferably, the Co generated in step (S1) is... x O y The substance can be CoO.

[0069] For reference, the substance generated in step (S1) of this specification, namely Co x O y It refers to the main substance produced through heat treatment, but it is also possible that it contains small amounts of other substances along with it.

[0070] The Co generated in step (S1) x O y The material can have a porous structure with pores. Preferably, Co x O y The substance contains particles ranging from 0.001 to 10.0 cm. 3 / g of pores.

[0071] These pores are formed by the dissolution of oxygen (O2) and lithium (Li) ions during the reduction process of the waste secondary battery. The pores increase the specific surface area of ​​the positive electrode active material, thus improving the diffusion of lithium during the preparation of the regenerated LCO.

[0072] Additionally, the Co generated in step (S1) x O y The substance has a diameter of 0.3 to 50.0 m. 2 Specific surface area per g.

[0073] Step (S2) is used to process the generated Co x O y The step of mixing with a lithium-containing substance, wherein the lithium-containing substance mixed in step (S2) comprises one or more substances selected from the group consisting of LiOH, Li2CO3, LiNO3, and Li3PO4. Preferably, it comprises one or more substances selected from the group consisting of Li2CO3, LiNO3, and Li3PO4. Most preferably, it comprises one or more substances selected from the group consisting of Li2CO3 and Li3PO4.

[0074] The lithium-containing substances mixed in step (S2) are mixed in such a manner that lithium is relative to the Co generated in step (S1). x O y The molar ratio of Co (Li / Co) contained therein is 1.0 to 1.06.

[0075] The heat treatment in step (S3) can be performed at 800°C to 1,050°C.

[0076] In addition, the heat treatment in step (S3) can be performed by dry heat treatment or wet heat treatment. Dry heat treatment is performed by placing the sample in an oven, furnace, tube, etc., in the absence of moisture. Wet heat treatment can be performed by water heat treatment.

[0077] The advantages and features of the present invention, as well as the methods for achieving these advantages and features, will be clearly understood by referring to the embodiments described in detail below. However, the present invention is not limited to the embodiments listed below, and can be implemented in many different forms. The embodiments listed below are provided only to make the description of the present invention more complete, so that those skilled in the art to which this invention pertains can more clearly understand the present invention. The scope of the claims of the present invention is not limited by the embodiments described later, but should be determined by the matters recorded in the claims.

[0078] Example 1. Preparation of regenerated positive electrode active material 1

[0079] After separating the positive electrode plate containing active material and additives from waste lithium secondary batteries, it is reduced by heat treatment at 600°C in an inert gas environment (argon, Ar) to prepare porous CoO. Then, Li2CO3 is added (mixed) to the generated CoO at a molar ratio of 1.02:1 (Li2CO3:CoO), followed by heat treatment at 850°C at 158 ​​mAh / g to prepare regenerated positive electrode active material (LCO)1.

[0080] Example 2. Preparation of regenerated positive electrode active material 2

[0081] After separating the positive electrode plate containing active material and additives from waste lithium secondary batteries, it is thermally reduced at 700°C in an inert gas atmosphere (argon (Ar)) to prepare CoO with pores. Then, Li2CO3 is added (mixed) to the generated CoO at a molar ratio of 1.04:1 (Li2CO3:CoO), followed by thermal treatment at 850°C at 158 ​​mAh / g to prepare the regenerated positive electrode active material (LCO)2.

[0082] Experimental Example 1. Confirmation of the composition of the separated positive electrode plate

[0083] To confirm the composition of the positive electrode plates separated from waste lithium secondary batteries, the separated positive electrode plates were analyzed using X-ray photoelectron spectroscopy (XPS). The results are as follows: Figure 2 As shown.

[0084] Reference Figure 2 It can be confirmed that the positive electrode plates separated from waste lithium secondary batteries contain: lithium containing active materials, additives such as binder (PVDF), electrolyte, etc.

[0085] Experimental Example 1. Confirmation of pores on the generated CoO surface

[0086] 1.1. Specific Surface Area Analyzer (Brunauer Emmett Teller, BET)

[0087] To confirm that the positive electrode plate separated from the waste secondary battery in step (S1) of the present invention is reduced by heat treatment to generate CoO with pores, the specific surface area of ​​CoO prepared by the present invention, the regenerated positive electrode active material (LCO)1 and the commonly used positive electrode active material (LCO) were analyzed using a specific surface area analyzer (Brunauer Emmett Teller, BET), and the results are shown in [Table 1].

[0088] [Table 1]

[0089]

[0090] Referring to Table 1, it can be confirmed that, compared with the regenerated positive electrode active material 1 and commonly used positive electrode active materials, the CoO generated in step (S1) according to the present invention has the following pores, which have a denser pore size and a high specific surface area.

[0091] 1.2. Scanning Electron Microscope (SEM)

[0092] To verify the formation of porous CoO in step (S1) of the positive electrode plate separated from the waste secondary battery according to the present invention, the CoO generated in Example 1 was measured using a scanning electron microscope, and the porosity formation image was confirmed. The results are as follows: Figure 3 As shown.

[0093] Reference Figure 3 (a) When the CoO generated in Example 1 of the present invention is magnified, (b) it can be confirmed that pores are formed on the generated CoO, and (c) it can be confirmed that pores are also formed on the cross-section of the generated CoO. The pores may be formed by the dissolution of oxygen (O2) and lithium (Li) ions during the reduction process of the waste secondary battery. The results confirm that the CoO of the present invention has pores formed both internally and externally (on its surface).

[0094] Experimental Example 2. Comparison of the effects of heat treatment in step S1

[0095] 2.1. Comparison of heat treatment gas environments based on step (S1)

[0096] In the method for preparing regenerated positive electrode active material according to the present invention, in order to compare the heat treatment environment (gas environment) of step (S1), comparative regenerated positive electrode active materials 1 to 3 were prepared by heat treatment in an oxygen environment at 500°C, 600°C, and 700°C using Examples 1 and 2 and their comparative groups, and the X-ray diffraction patterns were measured. The results are as follows: Figure 4 As shown.

[0097] Reference Figure 4 It can be confirmed that (a) the regenerated positive electrode active materials 1 to 3, which were heat-treated at 500°C and 600°C to 700°C in an oxygen environment, exhibit X-ray diffraction patterns showing only the presence of the initial active material, regardless of the temperature range. Conversely, (b) the regenerated positive electrode active materials 1 and 2, which underwent step (S1) at 600°C and 700°C respectively in an argon environment, showed X-ray diffraction patterns indicating that all the active material was reduced and only the CoO form of cobalt oxide existed.

[0098] 2.2. Comparison of temperatures based on step (S1)

[0099] In the preparation method of the regenerated positive electrode active material according to the present invention, in order to compare the temperature range of step (S1), comparative regenerated positive electrode active material 4 was prepared under the same conditions as in Example 1, except that the heat treatment temperature of step (S1) was changed to 500°C. The X-ray diffraction pattern was measured, and the results are as follows: Figure 5 As shown.

[0100] Reference Figure 5 It can be confirmed that the comparative regenerated positive electrode active material 4, which undergoes step (S1) at 500°C, exhibits an X-ray diffraction pattern showing the coexistence of CoO and the active material, regardless of the temperature range. Conversely, the regenerated positive electrode active materials 1 and 2, which undergo step (S1) at 600°C and 700°C respectively, according to the present invention, show X-ray diffraction patterns where the active material is completely reduced and only CoO is present.

[0101] The results confirm that, most preferably, in order to prepare pure CoO with impurities completely removed by step (S1), the heat treatment of step (S1) should be performed in an inert gas environment, i.e., argon, with the temperature limited to the range of 510°C to 750°C.

[0102] Experimental Example 3. Confirmation of Layered Structure of Regenerated Positive Electrode Active Material

[0103] To confirm the structural characteristics of the regenerated positive electrode active material prepared according to the present invention, X-ray diffraction patterns were measured for the CoO generated in Example 1 and the regenerated positive electrode active material (LCO)1 prepared using the generated CoO. The results are as follows: Figure 6 As shown.

[0104] Reference Figure 6 It can be confirmed that the regenerated positive electrode active material (Example 1) prepared using the porous CoO prepared according to the present invention has a layered structure.

[0105] Experimental Example 3. Evaluation of the Electrochemical Performance of Regenerated Positive Electrode Active Material

[0106] To evaluate the electrochemical performance of the regenerated positive electrode active material prepared according to the present invention, the electrochemical performance of commonly used positive electrode active materials (LCO) was evaluated at 3.0 to 4.3 V, and the results are shown in [Table 2] and Figure 7 As shown.

[0107] [Table 2]

[0108] Charging capacity (mAh / g) Discharge capacity (mAh / g) efficiency(%) Commonly used positive electrode active materials 164.2 159.6 97.2 Regenerated positive electrode active material 1 163.9 158.7 96.8 Regenerated positive electrode active material 2 163.3 157.7 96.6

[0109] Referring to [Table 2] and Figure 7 It can be confirmed that the charge capacity, discharge capacity, and efficiency of commonly used positive electrode active materials, regenerated positive electrode active material 1, and regenerated positive electrode active material 2 are almost identical within the error range. This result confirms that the electrochemical performance of the regenerated positive electrode active material prepared according to this invention will not decrease, and excellent electrochemical characteristics can be achieved.

[0110] As can be understood from the above description, those skilled in the art can implement this invention in other specific forms without altering its technical concept or essential features. Therefore, the embodiments listed above are exemplary in all respects and are not limiting.

Claims

1. A method for preparing a regenerated positive electrode active material, characterized in that, include: (S1) The positive electrode plate separated from the waste secondary battery is heat-treated to generate Co. x O y The steps of material; (S2) To the generated Co x O y The steps of mixing lithium-containing substances into a material; (S3) The step of forming a regenerated positive electrode active material by heat treatment of the mixed material. In the Co x O y In the example, x and y have values ​​between 0 and 10. Step (S1) is performed in an inert gas or reducing gas environment. The heat treatment in step (S1) is performed in a temperature range of 510°C to 750°C. The positive electrode plate is reduced by the heat treatment performed in step (S1), thereby generating Co. x O y substance, The Co generated in step (S1) x O y The substance is CoO.

2. The method for preparing the regenerated positive electrode active material according to claim 1, characterized in that, The positive electrode plate separated from the waste secondary battery in step (S1) comprises: positive electrode active material, conductive material and adhesive.

3. The method for preparing the regenerated positive electrode active material according to claim 1, characterized in that, The Co generated in step (S1) x O y The material forms a porous structure.

4. The method for preparing the regenerated positive electrode active material according to claim 3, characterized in that, The Co generated in step (S1) x O y The substance contains particles ranging from 0.001 to 10.0 cm. 3 / g of pores.

5. The method for preparing the regenerated positive electrode active material according to claim 1, characterized in that, The Co generated in step (S1) x O y The material has a diameter of 0.3 to 50.0 m. 2 Specific surface area per g.

6. The method for preparing the regenerated positive electrode active material according to claim 1, characterized in that, The lithium-containing substance mixed in step (S2) includes one or more substances selected from the group consisting of LiOH, Li2CO3, LiNO3 and Li3PO4.

7. The method for preparing the regenerated positive electrode active material according to claim 1, characterized in that, The lithium-containing substances mixed in step (S2) are mixed in the following manner: Relative to the Co generated in step (S1) x O y The molar ratio of Co to lithium in the substance is 1.0 to 1.

06.

8. The method for preparing the regenerated positive electrode active material according to claim 1, characterized in that, The heat treatment in step (S3) is performed in a temperature range of 800°C to 1,050°C.

9. The method for preparing the regenerated positive electrode active material according to claim 8, characterized in that, The heat treatment in step (S3) is performed using either dry heat treatment or wet heat treatment.

10. A regenerated positive electrode active material, characterized in that, It is formed by the preparation method according to any one of claims 1 to 9.

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