Co-recovery leaching reaction system of waste lithium ion battery cathode material and application thereof, method for co-recovery of waste lithium ion battery cathode material

Abstract

The application discloses a kind of waste lithium ion battery positive electrode material co-recovery leaching reaction system and its application, waste lithium ion battery positive electrode material co-recovery method, waste lithium ion battery positive electrode material co-recovery leaching reaction system, including low potential positive electrode material, high potential positive electrode material and leaching solution;Leaching solution includes redox mediator substance, acid and solvent;The oxidation-reduction potential of redox mediator substance is between low potential positive electrode material and high potential positive electrode material.The method for waste lithium ion battery positive electrode material co-recovery is: low potential positive electrode material, high potential positive electrode material and leaching solution are mixed, and react under stirring condition.The method for waste lithium ion battery positive electrode material co-recovery of the application does not need to add sacrificial reagent, realizes the efficient synergic recovery of metal in mixed waste battery positive electrode material, avoids the cumbersome step of pre-sorting different positive electrode materials in traditional method.

Description

Technical Field

[0001] This invention belongs to the field of battery material recycling technology, specifically relating to a co-recycling leaching reaction system for waste lithium-ion battery cathode materials and its application, and a method for co-recycling waste lithium-ion battery cathode materials. Background Technology

[0002] With the widespread adoption of electric vehicles and energy storage systems, lithium-ion batteries are facing a large-scale retirement. The recycling of waste lithium-ion battery cathode materials mainly employs three methods: pyrometallurgy, hydrometallurgy, and direct regeneration. Pyrometallurgy typically relies on high-temperature smelting to recover basic metal elements. While the process is relatively simple, it is extremely energy-intensive and generates significant waste gas emissions. Hydrometallurgy is currently the most widely used method in industry, achieving high metal recovery rates by dissolving waste cathode materials through acidic or alkaline leaching. However, this method has significant limitations: on the one hand, it consumes large amounts of reagents, involves complex purification steps, and faces the risk of secondary pollution; on the other hand, traditional hydrometallurgical processes often struggle to efficiently recover lithium from highly stable lithium iron phosphate and usually require external redox reactions, resulting in significant energy consumption. Direct regeneration aims to regenerate cathode materials by minimizing structural damage, but it has extremely high requirements for the consistency of raw materials, making it difficult to guarantee the uniformity of product quality when processing complex mixed waste materials.

[0003] Faced with increasingly heterogeneous battery waste, existing processes heavily rely on costly pre-sorting steps and struggle to achieve synergistic processing of multiple components. Furthermore, traditional technologies excessively depend on sacrificial redox reagents, which not only increases operating costs and energy consumption but also imposes a heavy environmental burden. There is a lack of a sustainable recycling strategy capable of uniformly processing mixed cathode materials and achieving efficient synergistic value-added processing. Therefore, providing a recycling method that overcomes the aforementioned problems of high pre-sorting costs and strong reagent dependence while achieving synergistic value-added processing of mixed waste is one of the main approaches to solving these issues. Summary of the Invention

[0004] To address the problems mentioned in the background section, the present invention aims to provide a co-recycling leaching reaction system for waste lithium-ion battery cathode materials and its application, as well as a method for co-recycling waste lithium-ion battery cathode materials. The method for co-recycling waste lithium-ion battery cathode materials of the present invention is based on an electron recycling platform (ELP). By constructing an internal electron recycling system driven by redox mediators, it replaces the use of consumable oxidants or reductants in traditional processes, achieving efficient and synergistic recycling of metals in mixed waste battery cathode materials. It features mediator recycling, no need for external sacrificial reagents, adaptability to complex compositions, low energy consumption, and low emissions.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: On the one hand, the present invention provides a co-recycling leaching reaction system for waste lithium-ion battery cathode materials, including an electron donor, an electron acceptor, and a leachate; The electron donor is a low-potential positive electrode material, which is a low-potential positive electrode material from waste lithium-ion batteries. The electron acceptor is a high-potential positive electrode material; The leachate includes redox mediators, acids, and solvents; The redox potential of the redox mediator is between that of the low-potential cathode material and the high-potential cathode material.

[0006] Furthermore, the low-potential positive electrode material includes waste lithium iron phosphate positive electrode material from lithium-ion batteries; And / or, the high-potential cathode material includes at least one of waste lithium-ion battery nickel cobalt manganese oxide cathode material, waste lithium-ion battery cobalt oxide cathode material, and waste lithium-ion battery manganese oxide cathode material; or the high-potential cathode material includes at least one of waste zinc-manganese battery basic manganese oxide cathode material and waste Ni-Zn battery nickel hydroxide cathode material.

[0007] Furthermore, the redox mediator includes one of potassium iodide, sodium iodide, potassium ferricyanide, sodium ferricyanide, ferrous sulfate, and ferric chloride; And / or, the acid includes one of sulfuric acid, hydrochloric acid, and acetic acid; And / or, the solvent is water.

[0008] Furthermore, the concentration of the redox mediator in the leachate is 0.1~1.0 mol / L, and the concentration of the acid is 0.1~5 mol / L.

[0009] Too low a concentration of redox mediators will limit the electron transfer rate, while too high a concentration may lead to excessive accumulation of mediators or side reactions.

[0010] The acid concentration needs to be maintained sufficiently to support the reducing dissolution reaction of the high-potential cathode material. When the acid concentration is less than 0.1 mol / L, the dissolution of the high-potential cathode material is inhibited, and the metal leaching rate decreases significantly. When the acid concentration is greater than 5 mol / L, although it is beneficial to the reaction, it also causes partial dissolution of the low-potential cathode material, affecting subsequent separation. The preferred acid concentration is 0.5~1.5 mol / L, more preferably 1 mol / L.

[0011] Furthermore, the molar ratio of the electron donor to the electron acceptor is 1:(0.9~1.1). And / or, the ratio of the total mass of the electron donor and electron acceptor to the volume of the leachate is (5-50g):1L.

[0012] On the other hand, the present invention provides an application of the above-described waste lithium-ion battery cathode material co-recycling leaching reaction system in the extraction of at least one metal element from lithium, nickel, cobalt, and manganese, and / or in the co-upgrading and recycling of mixed waste battery cathode materials into lithium-ion battery cathode materials.

[0013] Furthermore, the mixed waste battery cathode material is a mixed waste lithium-ion battery cathode material, or a waste zinc battery cathode material and a waste lithium-ion battery cathode material.

[0014] On the other hand, the present invention provides a method for co-recycling waste lithium-ion battery cathode materials, using any of the above-described waste lithium-ion battery cathode material co-recycling leaching reaction systems, comprising the following steps: By mixing electron donors, electron acceptors, and leachate, and reacting under stirring conditions, synergistic leaching of metals can be achieved.

[0015] As long as the redox potential of the redox mediator is between that of the low-potential cathode material and the high-potential cathode material, the synergistic leaching of the mixed cathode material can be achieved. The mediator-mediated electronic cycling platform of this invention has universality.

[0016] Furthermore, it may also include the following steps: After the reaction is complete, slowly add alkali to neutralize the excess acid until the pH is neutral, then filter and separate to obtain filter residue and filtrate; The filtrate was subjected to co-precipitation treatment to obtain a hydroxide precursor.

[0017] Furthermore, the stirring speed is 100~1000 rpm, preferably 200~600 rpm; And / or, the reaction temperature is 20~80℃, and the reaction time is 0.5~6h.

[0018] Increasing the reaction temperature accelerates the reaction kinetics, but careful temperature control is necessary to avoid the volatilization or decomposition of the redox mediator. As the reaction temperature increases, the reaction rate accelerates, and the metal leaching rate improves. A leaching rate of >97% is achieved at 40℃. However, at temperatures above 60℃, increased volatilization loss of some redox mediators is observed, and the solution color becomes lighter. The preferred reaction temperature is 50–60℃, more preferably 60℃.

[0019] A stable high leaching rate (>97%) can be achieved with a reaction time of 1 hour, and further extending the reaction time has limited effect on improving the leaching rate. The preferred reaction time is 1~2 hours.

[0020] In another aspect, the present invention provides an apparatus for co-recycling waste lithium-ion battery cathode materials, comprising: A reaction vessel for holding electron donors, electron acceptors and leachates, as well as a stirring device.

[0021] Furthermore, the reaction vessel is equipped with heating and temperature control functions.

[0022] Furthermore, the device for co-recycling waste lithium-ion battery cathode materials requires no external electric field or electrodes; the reaction proceeds spontaneously through chemical drive.

[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention constructs a co-recycling leaching reaction system for waste lithium-ion battery cathode materials, including an electron circulation platform (ELP). It utilizes redox mediators to establish internal electron circulation between target materials. By matching redox potentials and balancing electron transfer, it achieves the synergistic recycling of mixed waste lithium-ion battery cathode materials (such as lithium iron phosphate (LFP), lithium manganese oxide (LMO), lithium cobalt oxide (LCO), and lithium nickel cobalt manganese oxide (NCM), as well as the co-recycling of waste zinc battery cathode materials (such as basic manganese oxide and nickel hydroxide) and waste lithium iron phosphate cathode materials. This invention achieves efficient recovery of metallic nickel, cobalt, manganese, and lithium, and the simultaneous acquisition of highly reusable iron phosphate. The recovery rate of target metals in various cathode materials exceeds 97%, avoiding the cumbersome pre-sorting steps required by traditional methods for different cathode materials.

[0024] (2) This invention creatively utilizes an internal electron circulation mechanism driven by redox mediators to recycle waste lithium-ion batteries. By designing a matched redox potential, the redox mediators spontaneously transfer electrons between materials with high and low potentials, replacing the reliance on external consumable oxidants or reductants in traditional hydrometallurgy. This method eliminates the need for large amounts of acidic reagents, avoids the risk of gas evolution and high energy consumption, and achieves efficient lithium extraction and high-value metal recovery while reducing operational complexity and environmental burden.

[0025] (3) The method for co-recycling waste lithium-ion battery cathode materials of the present invention realizes programmable co-recycling of inorganic waste by establishing a unified and minimized reagent consumption co-recycling strategy. It can transform mixed inorganic waste streams from environmental burdens into sources of customized functional materials, and provides an scalable solution for the transformation of inorganic resource management from linear recycling to integrated, value-added recycling. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating the principle of the co-recycling method for waste lithium-ion battery cathode materials according to the present invention and the traditional wet process; Figure 2 This is the UV-Vis absorption spectrum analysis of the co-recycling process of waste lithium-ion battery cathode materials in Example 1 of the present invention; Figure 3 The images show the scanning electron microscope (SEM) image and elemental distribution map of the hydroxide precursor in Example 6 of this invention. Figure 4 This is a wide-angle X-ray scattering diagram of the LRM cathode material in Embodiment 6 of the present invention; Figure 5 This is a refined XRD pattern of the LRM cathode material in Example 6 of the present invention; Figure 6 This is a cyclic voltammetry curve of the LRM / / lithium half-cell of the present invention; Figure 7 This is a constant current charge-discharge curve of the LRM / / lithium half-cell of the present invention. Figure 8 This is a cycle performance diagram of the LRM / / lithium half-cell of the present invention; Figure 9 This is a cycle performance diagram of the LRM / / graphite full cell of the present invention. Detailed Implementation

[0027] The technical solution will now be clearly and completely described in conjunction with embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] In this invention, the term "and / or" is used to describe the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. A and B can be singular or plural.

[0029] In this invention, the terms "comprising," "including," "having," and "containing" are all open-ended terms, meaning that they include but are not limited to.

[0030] Those skilled in the art should understand that, in the following description of the embodiments of the present invention, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0031] Those skilled in the art will understand that the numerical ranges in this invention should be understood to specifically disclose each intermediate value between the upper and lower limits of the range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0032] Unless otherwise stated, the technical / scientific terms used in this invention have the same meanings as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials are described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention.

[0033] The technical principle employed in this invention is as follows: This invention constructs an electron circulation platform (ELP) mediated by redox mediators, utilizing the reversible redox transformation of redox mediators between different cathode materials to achieve the synergistic recovery of metals from mixed waste battery cathode materials. This platform is designed based on matched redox potentials, enabling the reduced mediator to be oxidized to an oxidized state at the low-potential cathode material (LFP), while simultaneously recovering Li₂ from the LFP. + The oxidized mediator is released; it is then reduced back to the reduced state mediator at high-potential cathode materials (such as NCM, LCO, LMO, etc.), driving these materials to... + Reductive dissolution with the participation of the redox mediator. Through this internal electron circulation mechanism, the redox mediator is repeatedly regenerated during the reaction process, without the need for external consumable oxidants or reductants, or external electric fields.

[0034] Prior to this application, a series of experiments were conducted. Some of the experimental results are listed below to further describe this invention in detail. The following is a detailed description in conjunction with the embodiments.

[0035] It should be noted that all raw materials and reagents in the following examples are commercially available or prepared using conventional methods known to those skilled in the art.

[0036] Example 1 The waste lithium-ion battery cathode material recycling leaching reaction system includes an electron donor, an electron acceptor, and a leachate. The electron donor is waste lithium-ion battery LFP cathode material (denoted as LFP). The electron acceptors are waste lithium-ion battery NCM622 cathode material (denoted as NCM622), waste lithium-ion battery LCO cathode material (denoted as LCO), and waste lithium-ion battery LMO cathode material (denoted as LMO). The leachate includes potassium iodide, sulfuric acid, and deionized water, with a potassium iodide concentration of 0.4 mol / L and a sulfuric acid concentration of 1 mol / L.

[0037] Method for co-recycling waste lithium-ion battery cathode materials: (1) Dissolve 0.4 mol potassium iodide and 1 mol sulfuric acid in deionized water, and bring the volume to 1 L to obtain a leachate, wherein potassium iodide serves as the mediator source and sulfuric acid provides an acidic environment. (2) Mix 50 mg LCO, 50 mg LMO, 50 mg NCM622, and 200 mg LFP, and then add them to 18 mL of leachate to obtain a mixed system; place the mixed system in a reaction vessel and stir magnetically at 400 rpm for 1 h at 60 °C. During the reaction, the redox mediator (potassium iodide) establishes an internal electron cycle between the electron donor (LFP) and the electron acceptor (LCO, LMO, NCM622), driving the synergistic leaching of high-value metals. The co-recycling method for waste lithium-ion battery cathode materials of this invention and the reaction principle of the traditional wet process are as follows: Figure 1 As shown. (3) After the reaction is complete, KOH is slowly added to neutralize the excess acid to pH neutral, and then the mixture is filtered to separate the filtrate and filter residue. The filtrate contains leached lithium ions, nickel ions, cobalt ions and manganese ions, and the filter residue mainly contains carbon and iron phosphate. (4) The filtrate is subjected to co-precipitation treatment: under the condition of 55℃ and continuous stirring, 790μL of 0.5mol / L ammonium sulfate solution is added dropwise to the above filtrate for reaction, and 1mol / L KOH solution is continuously added to maintain the pH value of the system at 11-12. After the precipitation reaction is 2h, the solid precipitate is collected by filtration, washed thoroughly with deionized water, and vacuum dried overnight at 80℃ to obtain the hydroxide precursor.

[0038] The concentrations of various metal ions in the filtrate were determined using ICP-OES. The leaching rates were 99.6% for Li, 99.1% for Ni, 97.5% for Co, and 97.4% for Mn. The method provided by this invention can achieve efficient synergistic leaching of metals from mixed waste battery cathode materials under mild conditions (60°C, atmospheric pressure, 1 h).

[0039] To verify the cyclic transformation mechanism of the mediator during the reaction, UV-Vis spectrometry was performed every 1 minute during the reaction to observe I3. - The characteristic absorption peaks (288 nm and 352 nm) changed, and the results are as follows: Figure 2 As shown (experimental data are only represented by LCO). From Figure 2 It can be seen from this that in the initial stage of the reaction, I3 - The characteristic peak gradually increases, indicating that I - Oxidized to I3 - As the reaction proceeds, I3 - The characteristic peak gradually weakens, indicating that I3 - Restored to I -It is evident that the electronic circulation platform constructed in this invention can realize the regeneration and circulation of the medium, and achieve a continuous supply of oxidized medium to continuously drive metal leaching.

[0040] Example 2 Following the steps of Example 1, only the sulfuric acid concentration was changed to 0.1 mol / L, 0.5 mol / L, 2 mol / L, and 5 mol / L, respectively. Other conditions were the same as in Example 1.

[0041] Example 3 Following the steps of Example 1, only the reaction temperature was changed to 20°C, 40°C, and 80°C, respectively. Other conditions were the same as in Example 1.

[0042] Example 4 Following the steps of Example 1, only the reaction time was changed to 0.5h, 2h, 4h, and 6h respectively. Other conditions were the same as in Example 1.

[0043] Example 5 The steps of Example 1 were followed, except that the redox mediator was changed to ferrous sulfate. All other conditions were the same as in Example 1.

[0044] Example 6 The waste lithium-ion battery cathode material recycling leaching reaction system includes an electron donor, an electron acceptor, and a leachate. The electron donor is waste lithium-ion battery LFP cathode material (denoted as LFP). The electron acceptor is waste zinc-manganese battery basic manganese oxide cathode material (denoted as basic manganese oxide) and waste Ni-Zn battery nickel hydroxide cathode material (denoted as nickel hydroxide). The leachate includes potassium iodide, sulfuric acid, and deionized water, with a potassium iodide concentration of 0.4 mol / L and a sulfuric acid concentration of 1 mol / L.

[0045] Method for co-recycling waste lithium-ion battery cathode materials: (1) Dissolve 0.4 mol potassium iodide and 1 mol sulfuric acid in deionized water, and make up to 1 L to obtain a leachate, in which potassium iodide serves as the mediator source and sulfuric acid provides an acidic environment. (2) Mix 1.83 g LFP, 0.74 g basic manganese oxide and 0.26 g nickel hydroxide, and then add them to 100 mL of leachate to obtain a mixed system; place the mixed system in a reaction vessel and stir magnetically at 400 rpm for 1 h at 60 °C. During the reaction, the redox mediator (potassium iodide) establishes an internal electron cycle between the electron donor (LFP) and the electron acceptor (basic manganese oxide and nickel hydroxide), driving the synergistic leaching of high-value metals. (3) After the reaction is completed, slowly add KOH to neutralize the excess acid to pH neutral, and then filter to separate the filtrate and filter residue. The filtrate contains leached lithium ions, nickel ions and manganese ions, and the filter residue mainly contains carbon and iron phosphate. (4) Co-precipitation treatment of the filtrate: Under the condition of continuous stirring at 55°C, 790 μL of 0.5 mol / L ammonium sulfate solution was added dropwise to the above filtrate for reaction, and 1 mol / L KOH solution was continuously added to maintain the pH value of the system at 11-12. After the precipitation reaction for 2 h, the solid precipitate was collected by filtration, washed thoroughly with deionized water, and vacuum dried overnight at 80°C to obtain the hydroxide precursor. (5) Upgrade and recycling into lithium-rich manganese-based (LRM) cathode material: 100 mg of hydroxide precursor and 40 mg of LiOH were mixed evenly by manual grinding, and then annealed at 900°C for 15 h in an oxygen atmosphere to obtain LRM cathode material.

[0046] The hydroxide precursor was subjected to SEM and EDS tests. The SEM images and corresponding EDS elemental mappings are shown below. Figure 3 As shown. From Figure 3 It can be seen that the hydroxide precursor has controllable particle size, morphology and uniform elemental distribution.

[0047] Wide-angle X-ray scattering (WAXS) characterization was performed on the LRM cathode material. The WAXS spectra are shown below. Figure 4 As shown. From Figure 4 As can be seen from the data, the diffraction rings correspond to the characteristic peaks of the LRM cathode material, indicating the successful synthesis of the material.

[0048] XRD tests were performed on the LRM cathode material, and the obtained data were refined using Rietveld to further verify the phase evolution. The results are as follows: Figure 5 As shown. From Figure 5 As can be seen, the diffraction peaks correspond to the diffraction rings in the WAXS pattern, which can be indexed as the crystal planes of the LRM cathode material.

[0049] Electrochemical performance of the LRM cathode material in Example 6: Preparation of LRM / / Lithium Half-Battery: LRM cathode material, acetylene black, and polyvinylidene fluoride dissolved in N-methylpyrrolidone were mixed in a planetary mixer (total mass of LRM cathode material, acetylene black, and polyvinylidene fluoride was 1 g, and the mass ratio of LRM cathode material, acetylene black, and polyvinylidene fluoride was 8:1:1) to form a homogeneous slurry. This slurry was coated onto aluminum foil and dried overnight at 80°C to obtain the cathode sheet. The cathode sheet was cut into circular pieces with a diameter of 12 mm and an areal loading of 3-4 mg / cm². -2 This material is used to assemble CR2032 coin cells, with lithium metal sheets as the negative electrode. The electrolyte is a 1 mol / L LiPF6 solution, and the solvent is a mixed solvent of ethylene carbonate (EC), dimethyl carbonate (DMC), and diethyl carbonate (DEC), with a volume ratio of 1:1:1.

[0050] Cyclic voltammetry (CV) tests were performed on the LRM / / lithium half-cell, and the results are as follows: Figure 6 As shown. From Figure 6 The CV curves from the first cycle show a distinct anodic plateau near 4.5V during charging, which disappears in the second cycle. This is attributed to the oxygen oxidation activity in the LRM cathode material. This characteristic confirms the successful formation of the target structure and verifies the effectiveness of the ELP co-recycling route.

[0051] The charge / discharge performance of the LRM / / lithium half-cell was tested, and the results are as follows: Figure 7 As shown. From Figure 7 As can be seen, the initial specific capacity of the LRM cathode material at a 0.1C rate is 270 mAh g. -1 The cathode energy density reaches 970Wh / kg. -1 .

[0052] The cycle performance of the LRM / / lithium half-cell was tested at 0.5C rate, and the results are as follows: Figure 8 As shown. From Figure 8 As can be seen, after 200 cycles, the specific capacity retention rate is 84.3%.

[0053] Preparation of LRM / / graphite full cells: LRM cathode material, acetylene black, and PVDF dissolved in NMP were mixed in a planetary mixer (total mass of LRM cathode material, acetylene black, and PVDF was 1 g, and the mass ratio of LRM cathode material, acetylene black, and PVDF was 8:1:1) to form a homogeneous slurry. This slurry was coated onto aluminum foil and dried overnight at 80°C to obtain the cathode sheet. The cathode sheet was cut into circular pieces with a diameter of 12 mm and an areal loading of 3-4 mg / cm³. -2Graphite, acetylene black, and carboxymethyl cellulose dissolved in deionized water were mixed in a planetary mixer (total mass of graphite, acetylene black, and carboxymethyl cellulose was 1 g, and the mass ratio of graphite, acetylene black, and carboxymethyl cellulose was 94:2:2) to form a homogeneous slurry. Styrene-butadiene rubber (SBR) was then added to the slurry, and the mixture was continued in a planetary mixer (mass ratio of graphite to SBR was 94:2) to form the final slurry. This slurry was coated onto copper foil and dried overnight at 80°C to obtain the negative electrode sheet. The negative electrode sheet was cut into circular pieces with a diameter of 12 mm and an areal loading of 1.8-2.2 mg / cm². -2 The electrodes prepared above were used to assemble CR2032 coin cells. The electrolyte was a 1 mol / L LiPF6 solution, and the solvent was a mixed solvent of ethylene carbonate (EC), dimethyl carbonate (DMC), and diethyl carbonate (DEC), with a volume ratio of 1:1:1.

[0054] The cycling performance of LRM / / graphite full cells at 0.5C rate was tested, and the results are as follows: Figure 9 As shown. From Figure 9 As can be seen from this, the initial specific capacity exceeds 200 mAh g. -1 After 200 cycles, the specific capacity retention rate exceeds 75%.

[0055] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any reversible redox mediator with a redox potential between that of a low-potential cathode material and a high-potential cathode material can be used to implement the present invention. For those skilled in the art, modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the principles of the present invention, and these modifications and equivalent substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A co-recycling leaching reaction system for waste lithium-ion battery cathode materials, characterized in that, Includes electron donors, electron acceptors, and leachates; The electron donor is a low-potential positive electrode material, which is a low-potential positive electrode material from waste lithium-ion batteries. The electron acceptor is a high-potential positive electrode material; The leachate includes redox mediators, acids, and solvents; The redox potential of the redox mediator is between that of the low-potential cathode material and the high-potential cathode material.

2. The co-recycling leaching reaction system for waste lithium-ion battery cathode materials according to claim 1, characterized in that, The low-potential cathode material includes waste lithium iron phosphate cathode material from lithium-ion batteries. And / or, the high-potential cathode material includes at least one of waste lithium-ion battery nickel cobalt manganese oxide cathode material, waste lithium-ion battery cobalt oxide cathode material, and waste lithium-ion battery manganese oxide cathode material; or the high-potential cathode material includes at least one of waste zinc-manganese battery basic manganese oxide cathode material and waste Ni-Zn battery nickel hydroxide cathode material.

3. The co-recycling leaching reaction system for waste lithium-ion battery cathode materials according to claim 1, characterized in that, The redox mediator includes one of potassium iodide, sodium iodide, potassium ferricyanide, sodium ferricyanide, ferrous sulfate, and ferric chloride. And / or, the acid includes one of sulfuric acid, hydrochloric acid, and acetic acid; And / or, the solvent is water.

4. The co-recycling leaching reaction system for waste lithium-ion battery cathode materials according to claim 3, characterized in that, The concentration of redox mediator in the leachate is 0.1~1.0 mol / L, and the concentration of acid is 0.1~5 mol / L.

5. The co-recycling leaching reaction system for waste lithium-ion battery cathode materials according to claim 1, characterized in that, The molar ratio of the electron donor to the electron acceptor is 1:(0.9~1.1). And / or, the ratio of the total mass of the electron donor and electron acceptor to the volume of the leachate is (5-50g):1L.

6. The application of the waste lithium-ion battery cathode material co-recycling leaching reaction system according to any one of claims 1 to 5 in the extraction of at least one metal element in lithium, nickel, cobalt, and manganese, and / or in the co-upgrading and recycling of mixed waste battery cathode materials into lithium-ion battery cathode materials.

7. The application according to claim 6, characterized in that, The mixed waste battery cathode material is a mixed waste lithium-ion battery cathode material, or a waste zinc battery cathode material and a waste lithium-ion battery cathode material.

8. A method for co-recycling waste lithium-ion battery cathode materials, characterized in that, The co-recycling leaching reaction system for waste lithium-ion battery cathode materials according to any one of claims 1 to 5 includes the following steps: By mixing electron donors, electron acceptors, and leachate, and reacting under stirring conditions, synergistic leaching of metals can be achieved.

9. The method according to claim 8, characterized in that, It may also include the following steps: After the reaction is complete, slowly add alkali to neutralize the excess acid until the pH is neutral, then filter and separate to obtain filter residue and filtrate; The filtrate was subjected to co-precipitation treatment to obtain a hydroxide precursor.

10. The method according to claim 8 or 9, characterized in that, The stirring speed is 100~1000 rpm; And / or, the reaction temperature is 20~80℃, and the reaction time is 0.5~6h.

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