Selective leaching and regeneration method and application of layered ternary material based on mixed cathode

Abstract

The invention discloses a selective leaching and regeneration method and application of a layered ternary material based on a mixed cathode, and belongs to the technical field of waste lithium ion battery recovery. The method comprises the following steps: selectively separating a low-value spinel electrode material from a mixed cathode electrode by utilizing different stability of transition metal in an acid medium and ascorbic acid, treating a layered nickel-rich material under an alkaline hydrothermal condition, separating a manganese element and a nickel element in the mixed cathode electrode, and directly recycling and regenerating the waste layered nickel-rich oxide. By adopting the method, the manganese element and the nickel element in the positive electrode material can be effectively separated while the recovery cost is reduced, and the waste layered nickel-rich oxide is directly recovered. The battery prepared from the positive electrode material recycled by the technology is good in electrical performance, and the recycling method is simple and reasonable, controllable in cost, less in waste and suitable for commercial production.

Description

Technical Field

[0001] The invention relates to the technical field of waste lithium-ion battery recycling, and in particular to a selective leaching and regeneration method and application of a layered ternary material based on a mixed cathode. Background Art

[0002] With the rapid development of electric vehicles and energy storage devices, the use of lithium-ion batteries (LIBs) is booming, and the number of consumed LIBs is also increasing. Therefore, battery recycling has become one of the focuses of interest in both industry and academia. Currently, thermal and hydrometallurgical recovery methods are widely used to extract valuable lithium and transition metal elements from degraded batteries for reuse. However, the high-temperature smelting involved in the pyrometallurgical method and the strong acid leaching in the hydrometallurgical method have raised concerns about energy consumption and pollution. Therefore, the development of direct recovery of spent cathode materials can serve as a promising alternative.

[0003] As a highly-regarded energy storage technology, the recycling and reuse of positive electrode materials of lithium-ion batteries can greatly alleviate energy consumption. The key to the recycling of positive electrode materials is to re-adsorb lithium ions and replenish the consumption of lithium ions.

[0004] During the charging and discharging process of lithium-ion batteries, the material itself usually causes some lithium ions to be inactivated, which will damage the battery's cycle stability to a certain extent. As the number of cycles increases, the discharge capacitance and capacity will drop rapidly.

[0005] Therefore, in view of the shortcomings of the prior art, a method is provided to compensate for the deactivated lithium ions in the battery after the battery is cycled. Summary of the invention

[0006] The purpose of the present invention is to provide a selective leaching and regeneration method and application of layered ternary materials based on a mixed cathode, which can effectively separate the manganese and nickel elements in the positive electrode material while reducing the recycling cost, and directly recycle the waste layered nickel-rich oxide. The positive electrode material recycled by this technology has good electrical performance when prepared into a battery, and the recycling method is simple and reasonable, the cost is controllable, and the waste is small, which is suitable for commercial production.

[0007] To achieve the above-mentioned purpose, the present invention provides a method for selective leaching and regeneration of layered ternary materials based on a mixed cathode, utilizing the different stabilities of transition metals in acidic media, using ascorbic acid to selectively precipitate low-value spinel electrode materials from the mixed cathode electrode, treating the layered nickel-rich material under alkaline hydrothermal conditions, separating the manganese and nickel elements in the mixed cathode electrode, and directly recovering and regenerating the waste layered nickel-rich oxide.

[0008] Preferably, the mixed cathode electrode contains LiMn2O4 / layered nickel-rich oxide, and the transition metals are nickel, cobalt and manganese.

[0009] Preferably, the method comprises two steps of selective leaching of manganese-rich material and recovery and regeneration of layered nickel-rich oxide.

[0010] Preferably, the selective leaching of manganese-rich material specifically comprises the following steps: (1) disassembling the layered ternary material to obtain a waste battery positive electrode material, preparing ascorbic acid into a solution of a certain concentration, and mixing the solution with the waste battery positive electrode material to obtain a mixed material 1; (2) Mixture 1 is heated to obtain mixture 2, and mixture 2 is separated into a leachate and a solid substance for solid-liquid separation.

[0011] Preferably, the layered ternary material is disassembled from waste electric vehicle batteries, and the leachate in the mixed material 2 is a low-value spinel electrode material leachate and the solid matter is a layered nickel-rich oxide.

[0012] Preferably, the recovery and regeneration of layered nickel-rich oxide specifically comprises the following steps: S1. The layered nickel-rich oxide separated from the mixed material 2 is crushed into particles of 2-3 μm by a high-energy ball mill, and the layered nickel-rich oxide particles and the hot alkaline solution are added to a reaction kettle and mixed with continuous heating and stirring to decompose polyvinylidene fluoride and obtain layered metal hydroxide M(OH)2, wherein M is Ni, Co, Mn and Al; S2, grinding the obtained layered metal oxide and the remaining layered nickel-rich oxide together to obtain a powder mixture, and filtering, washing, and drying the powder mixture to obtain a powder mixture A; S3, heating the powder mixture A in an atmosphere furnace to obtain powder B, and performing EDTA chemical titration and ICP detection on the powder; S4. Powder B is placed in an atmosphere furnace and mixed with a lithium source and heated to obtain a regenerated layered nickel-rich oxide, i.e., a regenerated layered ternary positive electrode material.

[0013] Preferably, the concentration of ascorbic acid in step (1) is 1-1.5M, the material-liquid ratio of waste battery material to ascorbic acid is 1:40, and the heating temperature of the mixed material 2 in step (2) is 40-80°C, and the heating time is 5-10 min.

[0014] Preferably, the hot alkaline solution in step S1 is a sodium hydroxide solution, the concentration of the sodium hydroxide solution is 0.5N, wherein N is the molar amount of the metal element in the layered nickel-rich oxide particles, the heating temperature of the reactor is 160° C., and the stirring heating time is 2-12 h.

[0015] Preferably, the atmosphere in the atmosphere furnace in step S2 is an air atmosphere, and the mixture A is heated in the atmosphere furnace at a temperature of 400-500° C. for a heating time of 10-12 h; In step S4, the lithium sources are water and lithium hydroxide, the heating temperature of powder B in the atmosphere furnace is 700-900° C., and the heating time is 10-12 hours.

[0016] The present invention also provides an application of the above-mentioned method for selective leaching and regeneration of layered ternary materials based on a mixed cathode, characterized in that it is applied to the separation of components of a variety of cathode mixtures and the recovery of nickel-rich components in lithium-ion batteries.

[0017] Therefore, the present invention adopts the above-mentioned selective leaching and regeneration method and application of layered ternary materials based on mixed cathode, which has the following beneficial effects: 1. The present invention utilizes the different stabilities of transition metals in acidic media, uses ascorbic acid to leach manganese-rich materials from waste battery materials, and effectively separates layered nickel-rich oxides, which are then directly recycled into usable lithium-ion battery positive electrode materials.

[0018] 2. The regenerated layered ternary positive electrode material recovered by this method is used to prepare the positive electrode of lithium-ion batteries, and the positive electrode is used in lithium-ion batteries with good electrical performance.

[0019] 3. This method is simple to operate, low in cost, and has less waste of elements such as lithium and nickel. It also reduces potential aluminum pollution during the regeneration process and has commercial application value.

[0020] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the SEM image of the sample obtained in Example 1.

[0022] Figure 2 is the XRD pattern of the sample obtained in Example 1 of the present method; Figure 3 The first cycle charge and discharge curves of the sample application examples obtained in Example 1 of the present invention and the sample application examples obtained in Comparative Example 1 in the present method within a voltage range of 2.9-4.3V and at a rate of 0.1C; Figure 4 It is a comparison chart of the cycle rates of the sample application example prepared in Example 1 of the present invention and the sample application example prepared in Comparative Example 1. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0024] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0025] In addition, it should be understood that although this specification is described according to the implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. These other implementation modes are also covered within the protection scope of the present invention.

[0026] The present invention provides a method for selective leaching and regeneration of layered ternary materials based on a mixed cathode, which utilizes the different stabilities of transition metals in acidic media, utilizes ascorbic acid to selectively precipitate low-value spinel electrode materials from a mixed cathode electrode, treats layered nickel-rich materials under alkaline hydrothermal conditions, separates manganese and nickel elements in the mixed cathode electrode, and directly recovers and regenerates waste layered nickel-rich oxides.

[0027] The mixed cathode electrode contains LiMn2O4 / layered nickel-rich oxide, and the transition metal layer is a metal layer containing nickel, cobalt and manganese elements.

[0028] The selective leaching and regeneration method of layered ternary materials based on a mixed cathode includes two steps: selective leaching of manganese-rich materials and recovery and regeneration of layered nickel-rich oxides.

[0029] The selective leaching of manganese-rich materials specifically includes the following steps: (1) disassembling the layered ternary material to obtain a waste battery positive electrode material, preparing ascorbic acid into a solution of a certain concentration, and mixing the solution with the waste battery positive electrode material to obtain a mixed material 1; (2) Mixture 1 is heated to obtain mixture 2, and mixture 2 is separated into a leachate and a solid substance for solid-liquid separation.

[0030] The layered structured ternary material is disassembled from waste electric vehicle batteries, and the leachate in the mixed material 2 is a low-value spinel electrode material leachate and the solid matter is a layered nickel-rich oxide.

[0031] The recovery and regeneration of layered nickel-rich oxide specifically includes the following steps: S1. The layered nickel-rich oxide separated from the mixed material 2 is crushed into particles of 2-3 μm using a high-energy ball mill, and the layered nickel-rich oxide particles and the hot alkaline solution are added into a reactor and mixed with continuous heating and stirring to decompose polyvinylidene fluoride and obtain layered metal hydroxide M(OH)2, wherein M is Ni, Co, Mn and Al.

[0032] S2, grinding the obtained layered metal oxide and the remaining layered nickel-rich oxide together to obtain a powder mixture, and filtering, washing, and drying the powder mixture to obtain a powder mixture A; S3, heating the powder mixture A in an atmosphere furnace to obtain powder B, and performing EDTA chemical titration and ICP detection on the powder; S4. Powder B is placed in an atmosphere furnace and mixed with a lithium source and heated to obtain a regenerated layered nickel-rich oxide, i.e., a regenerated layered ternary positive electrode material.

[0033] In step (1), the concentration of ascorbic acid is 1-1.5M, the material-liquid ratio of waste battery material to ascorbic acid is 1:40, and the heating temperature of the mixed material 2 in step (2) is 40-80°C, and the heating time is 5-10min.

[0034] The hot alkaline solution in step S1 is a sodium hydroxide solution with a concentration of 0.5N, wherein N is the molar amount of the metal element in the layered nickel-rich oxide particles. The heating temperature of the reactor is 160° C. and the stirring heating time is 2-12 hours.

[0035] In step S2, the atmosphere in the atmosphere furnace is an air atmosphere, and the mixture A is heated in the atmosphere furnace at a temperature of 400-500° C. for a heating time of 10-12 h; In step S4, the lithium sources are water and lithium hydroxide, the heating temperature of powder B in the atmosphere furnace is 700-900° C., and the heating time is 10-12 hours.

[0036] The present invention also provides an application of the above-mentioned selective leaching and regeneration method of layered ternary materials based on a mixed cathode, which is applied to the separation of components of various cathode mixtures and the recovery of nickel-rich components in lithium-ion batteries.

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Any other changes, modifications, substitutions, combinations, and simplifications made without violating the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention. In addition, it should be understood that after reading the contents of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application, and all belong to the scope of protection of the present invention.

[0038] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0039] Unless otherwise specified in the present invention, the reagents, instruments, and equipment used are those commonly used by technicians in this field.

[0040] Example 1 NCA Ni 0.800 Co 0.148 Mn 0.007 Al 0.048 A method for selective leaching and regeneration of layered ternary materials based on a hybrid cathode comprises the following steps: First, the waste battery 1 is disassembled to obtain 20 g of the waste battery positive electrode material, ascorbic acid (AA) is prepared into a 1.25 M solution, and is mixed with the waste battery positive electrode material at a material-liquid ratio of 1:40 to obtain a mixed material 1.

[0041] The mixed material 1 was heated at 70°C for 5 minutes to obtain the mixed material 2, and the mixed material 2 was subjected to solid-liquid separation to obtain a solid layered nickel-rich oxide (LO), which was placed in a high-energy ball mill and crushed to 2 μm.

[0042] Layered nickel-rich oxide (LO) particles and 5 M NaOH solution were added into a reactor, mixed and heated at 160°C with stirring for 12 h to decompose PVDF and obtain layered metal hydroxides M(OH)2 (M is Ni, Co, Mn and Al).

[0043] The obtained powder was filtered, washed, and vacuum dried to 120° C. to obtain powder A.

[0044] Powder A was placed in an atmosphere furnace, the atmosphere in the atmosphere furnace was air atmosphere, and the temperature was heated at 450°C for 12 hours to obtain powder B. The powder B was subjected to EDTA chemical titration method, and the mass fraction of the TM layer was measured to be 56%. The powder was subjected to aqua regia acid dissolution and ICP detection, and the molar ratios of Li / Ni, Li / Co, Li / Mn, and Li / Al were determined to be 0.87:0.8, 0.87:0.148, 0.87:0.07, and 0.87:0.048, respectively.

[0045] Powder B was placed in an atmosphere furnace and mixed with 11g of lithium hydroxide monohydrate and heated at 850°C for 12h. The atmosphere in the atmosphere furnace was an oxygen atmosphere, and then cooled to room temperature to obtain regenerated LO, that is, regenerated layered ternary cathode material LiNi 0.800 Co 0.148 Mn 0.007 Al0.048 O2.

[0046] Figure 1 This is a SEM image of the sample obtained in Example 1. The results show that the sample has uniform particle size, good dispersion, clear grain boundaries, no obvious cracks or pores, and good morphology.

[0047] Figure 2 This is the XRD diagram of the sample obtained in Example 1 of the present method; its XRD diagram shows that the sample has a good layered structure.

[0048] Example 2 LiNi 0.800 Co 0.149 Mn 0.005 Al 0.049 O2 A method for selective leaching and regeneration of layered ternary materials based on a hybrid cathode comprises the following steps: First, the waste battery 2 is disassembled to obtain 20 g of the waste battery positive electrode material, ascorbic acid (AA) is prepared into a 1.25 M solution, and is mixed with the waste battery positive electrode material at a material-liquid ratio of 1:40 to obtain a mixed material 1.

[0049] The mixed material 1 was heated at 70° C. for 5 min to obtain the mixed material 2. The mixed material 2 was subjected to solid-liquid separation to obtain a solid layered nickel-rich oxide (LO), which was placed in a high-energy ball mill and crushed to 2 μm.

[0050] Layered nickel-rich oxide (LO) and 10 mL of 1M NaOH solution were added into a reactor, mixed and heated at 160°C with stirring for 12 h to decompose PVDF and obtain layered metal hydroxides M(OH)2 (M is Ni, Co, Mn and Al).

[0051] The obtained powder was filtered, washed, and vacuum dried to 120° C. to obtain powder A.

[0052] Powder A was placed in an atmosphere furnace, the atmosphere in the atmosphere furnace was air atmosphere, and the temperature was heated at 450℃ for 12h to obtain powder B. Powder B was subjected to EDTA chemical titration method, and the mass fraction of TM layer was measured to be 52%. The powder was further dissolved in aqua regia and ICP tested, and the molar ratios of Li / Ni, Li / Co, Li / Mn, and Li / Al were determined to be 0.82:0.8, 0.82:0.149, 0.82:0.05, and 0.82:0.049, respectively. Powder B was mixed with 13 g of lithium hydroxide monohydrate in an atmosphere furnace and heated at 850 ° C for 12 h. The atmosphere in the atmosphere furnace was an oxygen atmosphere. Then it was cooled to room temperature to obtain regenerated LO, that is, regenerated layered ternary cathode material LiNi 0.800 Co 0.149Mn 0.005 Al 0.049 O2.

[0053] Example 3 LiNi 0.800 Co 0.144 Mn 0.009 Al 0.05 O2 A method for selective leaching and regeneration of layered ternary materials based on a hybrid cathode comprises the following steps: First, the waste battery 3 is disassembled to obtain 20 g of the waste battery positive electrode material, ascorbic acid (AA) is prepared into a 1.25 M solution, and is mixed with the waste battery positive electrode material at a material-liquid ratio of 1:40 to obtain a mixed material 1.

[0054] The mixed material 1 was heated at 70° C. for 5 min to obtain the mixed material 2. The mixed material 2 was subjected to solid-liquid separation to obtain a solid layered nickel-rich oxide (LO), which was placed in a high-energy ball mill and crushed to 2 μm.

[0055] Layered nickel-rich oxide (LO) and 10 mL 1 M NaOH solution were added into a reactor, mixed and heated at 160 °C with stirring for 12 h to decompose PVDF and obtain layered metal hydroxides M(OH)2 (M is Ni, Co, Mn and Al).

[0056] The obtained powder was filtered, washed, and vacuum dried to 120° C. to obtain powder A.

[0057] Powder A was placed in an atmosphere furnace, the atmosphere in the atmosphere furnace was air atmosphere, and the temperature was heated at 450℃ for 12h to obtain powder B. Powder B was subjected to EDTA chemical titration method, and the mass fraction of TM layer was measured to be 59%. The powder was further dissolved in aqua regia and ICP tested, and the molar ratios of Li / Ni, Li / Co, Li / Mn, and Li / Al were determined to be 0.79:0.8, 0.79:0.144, 0.79:0.09, and 0.79:0.05, respectively. Powder B was mixed with 17 g of lithium hydroxide monohydrate in an atmosphere furnace and heated at 850 ° C for 12 h. The atmosphere in the atmosphere furnace was an oxygen atmosphere. Then it was cooled to room temperature to obtain regenerated LO, that is, regenerated layered ternary cathode material LiNi 0.800 Co 0.144 Mn 0.009 Al 0.05 O2.

[0058] Comparative Example 1: Recovery of NCA lithium using pyrometallurgy Step 1: Mix pyrometallurgical slag, water and hydrochloric acid to obtain a mixed acid material, wherein the mass ratio of slag: water: hydrochloric acid is 1: (0-2): (1-3), and the concentration of hydrochloric acid is 30wt%; Step 2: The mixed acid material is subjected to a heat-insulating reaction at a temperature of 85° C. for a reaction time of 4 hours, and the pH value at the reaction end point is controlled to be 2.5; Step 3: drying the mixed acid material after the reaction at 300° C. in vacuum to obtain an aluminum-removing material; Step 4: Soak the aluminum-removed material in water for 3 hours to obtain a leaching slurry; Step 5: performing solid-liquid separation on the leached slurry to obtain a leached liquid and a solid A; Step 6: adding lithium sulfate to the leaching solution, filtering, and obtaining a lithium chloride conversion solution and a solid B; Step 7: Separating lithium chloride from other divalent ions in the lithium chloride conversion solution to obtain a lithium chloride solution and a divalent ion salt solution; Step eight: preparing a lithium salt product from a lithium chloride solution.

[0059] The obtained lithium salt product is used as a lithium source to prepare NCA positive electrode material.

[0060] Example 1 Application example: The NCA material prepared in Example 1 is used as the positive electrode and the metal lithium sheet is used as the negative electrode to assemble into a button battery.

[0061] Application example of comparative example 1: the NCA material prepared in comparative example 1 is used as the positive electrode and the metal lithium sheet is used as the negative electrode to assemble into a button battery.

[0062] The electrochemical performance of the battery prepared in the application example of Example 1 and the battery prepared in Comparative Example 1 were tested, and the results of the two were compared. Figure 3 It is a first cycle charge and discharge curve diagram of the two at a voltage range of 2.9-4.3V and a rate of 0.1C; the first cycle charge and discharge specific capacity of Example 1 is higher than that of Comparative Example 1, indicating that the battery prepared by the regenerated layered ternary positive electrode material in the present invention has a higher energy storage capacity, less energy loss, and has more excellent performance; Figure 4 The figure is a comparison chart of the cycle rates of the two. The comparison results show that the energy retention rate and cycle performance of Example 1 are higher than those of Comparative Example 1, and the cycle life and energy utilization rate of the battery are excellent.

[0063] Therefore, the present invention adopts the above-mentioned selective leaching and regeneration method and application of layered ternary materials based on mixed cathodes, which can effectively separate manganese and nickel elements in positive electrode materials while reducing recycling costs, and directly recycle waste layered nickel-rich oxides. The positive electrode materials recycled by this technology are prepared into batteries with good electrical performance, and the recycling method is simple and reasonable, the cost is controllable, and the waste is small, which is suitable for commercial production.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for selective leaching and regeneration of layered ternary materials based on a mixed cathode, characterized in that: Taking advantage of the different stabilities of transition metals in acidic media, ascorbic acid is used to precipitate low-value spinel electrode materials from mixed cathode electrodes, layered nickel-rich materials are treated under alkaline hydrothermal conditions, manganese and nickel elements in the mixed cathode electrode are separated, and the waste layered nickel-rich oxides are directly recovered and regenerated.

2. A method for selective leaching and regeneration of layered ternary materials based on a mixed cathode according to claim 1, characterized in that: The mixed cathode electrode contains LiMn2O4 / layered nickel-rich oxide, and the transition metals are nickel, cobalt and manganese elements.

3. The selective leaching and regeneration method of layered ternary materials based on a mixed cathode according to claim 1, characterized in that: The method comprises two steps: selective leaching of manganese-rich materials and recovery and regeneration of layered nickel-rich oxides.

4. A method for selective leaching and regeneration of layered ternary materials based on a mixed cathode according to claim 3, characterized in that: The selective leaching of manganese-rich materials specifically includes the following steps: (1) disassembling the layered ternary material to obtain a waste battery positive electrode material, preparing ascorbic acid into a solution of a certain concentration, and mixing the solution with the waste battery positive electrode material to obtain a mixed material 1; (2) Mixed material 1 is heated to obtain mixed material 2, and mixed material 2 is separated into a leachate and a solid substance for solid-liquid separation.

5. A method for selective leaching and regeneration of layered ternary materials based on a mixed cathode according to claim 4, characterized in that: The layered ternary material is disassembled from waste electric vehicle batteries, the leaching solution in the mixed material 2 is a low-value spinel electrode material leaching solution, and the solid matter is a layered nickel-rich oxide.

6. A method for selective leaching and regeneration of layered ternary materials based on a mixed cathode according to claim 5, characterized in that: The recovery and regeneration of layered nickel-rich oxide specifically includes the following steps: S1. The layered nickel-rich oxide separated from the mixed material 2 is crushed into particles of 2-3 μm by a high-energy ball mill, and the layered nickel-rich oxide particles and the hot alkaline solution are added to a reaction kettle and mixed with continuous heating and stirring to decompose polyvinylidene fluoride and obtain layered metal hydroxide M(OH)2, wherein M is Ni, Co, Mn and Al; S2, grinding the obtained layered metal oxide and the remaining layered nickel-rich oxide together to obtain a powder mixture, and filtering, washing, and drying the powder mixture to obtain a powder mixture A; S3, heating the powder mixture A in an atmosphere furnace to obtain powder B, and performing EDTA chemical titration and ICP detection on the powder; S4. Powder B is placed in an atmosphere furnace and mixed with a lithium source and heated to obtain a regenerated layered nickel-rich oxide, i.e., a regenerated layered ternary positive electrode material.

7. A method for selective leaching and regeneration of layered ternary materials based on a mixed cathode according to claim 4, characterized in that: In step (1), the concentration of ascorbic acid is 1-1.5M, the material-liquid ratio of waste battery material to ascorbic acid is 1:40, and the heating temperature of the mixed material 2 in step (2) is 40-80°C, and the heating time is 5-10min.

8. A method for direct upgrading and recycling of waste nickel-rich layered positive electrode materials according to claim 6, characterized in that: The hot alkaline solution in step S1 is a sodium hydroxide solution with a concentration of 0.5N, wherein N is the molar amount of the metal element in the layered nickel-rich oxide particles. The heating temperature of the reactor is 160° C., and the stirring heating time is 2-12 h.

9. A method for selective leaching and regeneration of layered ternary materials based on a mixed cathode according to claim 6, characterized in that: In step S2, the atmosphere in the atmosphere furnace is an air atmosphere, and the mixture A is heated in the atmosphere furnace at a temperature of 400-500° C. for a heating time of 10-12 h; In step S4, the lithium sources are water and lithium hydroxide, the heating temperature of powder B in the atmosphere furnace is 700-900° C., and the heating time is 10-12 hours.

10. An application of the method for selective leaching and regeneration of layered ternary materials based on a mixed cathode as claimed in any one of claims 1 to 9, characterized in that: Applied to the separation of components of various cathode mixtures and the recovery of nickel-rich components in lithium-ion batteries.

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