Method for resource utilization of ternary lithium ion battery cathode material

Abstract

The application discloses a method for resource utilization of a ternary lithium ion battery positive electrode material, and comprises the following steps: (1) performing a hydrothermal displacement reaction on positive electrode material powder from a waste ternary lithium ion battery in the presence of a displacing agent and water, obtaining a Li-rich solution and a solid containing Ni elements, Co elements and Mn elements through solid-liquid separation; + (2) performing post-treatment on the Li-rich solution to obtain a Li-containing product; + (3) performing a hydrothermal reaction on the solid containing Ni elements, Co elements and Mn elements after acidic reduction to obtain an acid leaching solution, and optionally, (4) recycling the acid leaching solution for preparation of a positive electrode material. The resource utilization method has the advantages of simple process, high selectivity, applicable technology, economic feasibility and the like.

Description

Technical Field

[0001] This invention belongs to the field of waste battery recycling technology, specifically relating to a method for the resource utilization of ternary lithium battery cathode materials. Background Technology

[0002] With the widespread application of lithium-ion batteries in new energy vehicles and other fields, the quantity of spent ternary lithium-ion batteries (NCM) is constantly increasing, and the recycling and resource utilization of valuable metals in NCM has become a global hot topic. The most valuable part of spent ternary NCM is the cathode material. Based on the different proportions of valuable metals Ni, Co, and Mn in the cathode material, it is divided into models such as NCM523 and NCM622. The content of valuable metals is generally Ni 10%–30%, Co 5%–15%, Mn 10%–40%, and Li 2%–10%. The proportion of valuable metals is higher than that of some natural ores. Although my country has abundant Li reserves, its mining technology is lacking, resulting in Li resources still being monopolized by a few large foreign companies. Co resources are extremely scarce and mainly rely on imports. Therefore, the recycling of spent ternary NCM can not only solve environmental pollution problems, but also has significant implications for addressing the relative scarcity of valuable metals such as Li and Co in my country.

[0003] Currently, the recycling of waste ternary NCM cathodes can be categorized into several steps, including cathode pretreatment with valuable metal leaching and valuable metal separation and recovery. Based on the methods involved in the valuable metal leaching and separation steps, recycling is divided into three main categories: hydrometallurgical recycling, pyrometallurgical recycling, and combined pyrometallurgical and hydrometallurgical recycling. Currently, the primary industrial recycling method is hydrometallurgical recycling. Among hydrometallurgical processes, inorganic acid leaching offers high recovery efficiency but requires sophisticated equipment, and subsequent separation methods suffer from lengthy processes. Organic acid leaching is environmentally friendly with low pollution, but the high liquid-to-solid ratio results in large volumes of leaching wastewater that are difficult to treat and thus hinder industrialization. Ammonia leaching can selectively recover both cathode and anode materials but easily generates ammonia nitrogen wastewater. Summary of the Invention

[0004] To address the shortcomings and defects in the existing wet recycling process of waste ternary cathode materials, this invention provides a method for the resource utilization of waste ternary lithium-ion battery cathode materials. This method does not use acid or alkali leaching agents, achieves waste resource utilization under mild conditions, and features simple process, low cost, and high processing depth.

[0005] To achieve the above objectives, the present invention provides the following technical solution.

[0006] This invention provides a method for the resource utilization of waste ternary lithium-ion battery cathode materials, comprising the following steps:

[0007] (1) The cathode material powder from waste ternary lithium-ion batteries was subjected to a hydrothermal displacement reaction in the presence of a displacement agent and water, and Li-rich material was obtained by solid-liquid separation. + Solutions and solids containing Ni, Co, and Mn elements;

[0008] (2) Rich in Li + The solution was further processed to obtain a Li-containing product;

[0009] (3) A solid containing Ni, Co, and Mn elements is subjected to acid reduction followed by a hydrothermal reaction to obtain an acid leaching solution.

[0010] Optionally, step (4) involves recovering the acid leaching solution for use in the preparation of cathode materials.

[0011] In some embodiments, the displacement agent contains both cations and anions.

[0012] Preferably, the cation includes a metal cation and optionally NH4. + .

[0013] Preferably, the metal cation is selected from Ni. 2+ Co 2+ Mn 2+ At least one of them.

[0014] Preferably, the anion is selected from SO4. 2- NO3 - CO3 2- HCO3 - (OH)2CO3 2- or Cl - At least one of them.

[0015] Preferably, the replacement agent is one or more of the following: sulfates, ammonium sulfates, nitrates, chlorides, carbonates, bicarbonates, and basic carbonates of Ni, Co, and Mn.

[0016] In some embodiments, the displacement agent may be a pure substance or a mixture.

[0017] In some embodiments, the displacement agent is selected from water-soluble displacement agents or non-water-soluble displacement agents.

[0018] Preferably, the positive electrode material powder contains Li + The molar ratio of the metal cation in the water-soluble replacement agent to that in the positive electrode material powder is 10:(1-6), for example, 10:1, 10:2, 10:3, 10:4, 10:5, 10:6, or any value between them. More preferably, the Li in the positive electrode material powder... +The molar ratio of the metal cation in the water-soluble displacing agent is 10:(3-5). In some embodiments, the water-soluble displacing agent is a water-soluble displacing agent, such as manganese sulfate, nickel nitrate, cobalt ammonium sulfate, nickel ammonium sulfate, manganese ammonium sulfate, etc.

[0019] Preferably, the positive electrode material powder contains Li + The molar ratio of the metal cation in the non-water-soluble replacement agent to the positive electrode material powder is 10:(1-20), for example, 10:1, 10:5, 10:10, 10:15, 10:20, or any value between them. More preferably, the positive electrode material powder contains Li + The molar ratio of the metal cation in the non-water-soluble displacing agent is 10:(8-12). In some embodiments, the non-water-soluble displacing agent is a water-insoluble displacing agent, such as basic cobalt carbonate.

[0020] In some embodiments, the temperature of the hydrothermal displacement reaction is 120°C-250°C, for example, 120°C, 140°C, 160°C, 180°C, 200°C, 220°C, 240°C, 250°C, or any value between them. In some preferred embodiments, the temperature of the hydrothermal displacement reaction is 140°C-180°C.

[0021] In some embodiments, the hydrothermal replacement reaction takes 3-24 hours, for example, 3 hours, 5 hours, 10 hours, 15 hours, 20 hours, 24 hours, or any value between them. In some preferred embodiments, the hydrothermal replacement reaction takes 12-20 hours.

[0022] In some embodiments, the mass ratio of the positive electrode material powder to the volume ratio of water (solid-liquid ratio, g / mL) is less than 1 g / mL:1 g / mL, preferably 1:2 g / mL to 1:10 g / mL.

[0023] In some embodiments, the reducing agent used in step (3) for acid reduction includes hydrogen peroxide and / or hydrazine hydrate.

[0024] Preferably, the mass ratio (solid-liquid ratio, g / mL) of the solid containing Ni, Co and Mn elements to the volume ratio (solid-liquid ratio, g / mL) of the reducing agent is 5:1 g / mL to 1:2 g / mL.

[0025] Preferably, the acid used in the acid reduction includes at least one of sulfuric acid, hydrochloric acid, or nitric acid.

[0026] Preferably, the mass ratio (solid-liquid ratio, g / mL) of the solid containing Ni, Co and Mn elements to the volume ratio (solid-liquid ratio, g / mL) is 1:4 g / mL to 1:20 g / mL, and more preferably 1:8 g / mL to 1:15 g / mL.

[0027] Preferably, the acid contains H + The concentration is 3 mol / L to 10 mol / L, for example, 3 mol / L, 5 mol / L, 7 mol / L, 9 mol / L, 10 mol / L or any value between them.

[0028] Preferably, the acid reduction is carried out at a temperature of 20°C-35°C.

[0029] In some embodiments, in step (3), the temperature of the hydrothermal reaction is 120°C-250°C, for example, 120°C, 140°C, 160°C, 180°C, 200°C, 220°C, 240°C, 250°C, or any value between them. In some preferred embodiments, the temperature of the hydrothermal displacement reaction is 140°C-180°C.

[0030] In some embodiments, the hydrothermal reaction time is 1-20 hours, for example, 3 hours, 5 hours, 10 hours, 15 hours, 20 hours, 24 hours, or any value between them. In some preferred embodiments, the hydrothermal displacement reaction time is 2-5 hours.

[0031] In some implementations, in step (1), cathode material powder is obtained by discharging, dismantling, crushing and sieving the waste ternary lithium-ion battery.

[0032] In some embodiments, in step (2), the post-processing includes evaporation crystallization or concentration followed by precipitation.

[0033] In some embodiments, the concentration followed by precipitation includes: first concentrating the high-purity Li+ solution obtained in step (1) to Li... + The concentration is greater than 20 g / L, preferably 30 g / L to 40 g / L, and then a saturated carbonate solution is added at a reaction temperature of 80℃ to 120℃.

[0034] In some embodiments, the cathode material powder is derived from LiNi alloys. x Co y Mn 1-x-y A ternary lithium-ion battery composed of O2, wherein the value of x ranges from 0.4 to 0.7 and the value of y ranges from 0.1 to 0.25.

[0035] In some embodiments, the cathode material powder is derived from LiNi alloys. 0.5 Co 0.2 Mn 0.3 Ternary lithium-ion batteries composed of O2.

[0036] In some embodiments, the weight content of Ni is 10%-30%, the weight content of Co is 5%-15%, the weight content of Mn is 10%-40%, and the weight content of Li is 2%-10% based on the total weight of the cathode material powder.

[0037] This invention also provides the application of the above method in the preparation of ternary lithium-ion batteries.

[0038] The present invention has the following beneficial effects:

[0039] The method of adding a displacement agent provided by this invention solves the problem of high subsequent separation costs caused by the one-time leaching of all metals in existing wet recovery processes. This method turns waste into treasure, and the process is simple and efficient; moreover, the prepared Li-containing product has high purity and meets reagent-grade standards. In summary, this method is effective and has the advantages of technical applicability and economic feasibility. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the process flow for the resource utilization method of waste ternary lithium-ion battery cathode materials according to this application. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention in any way. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of this disclosure. Such structures and techniques have also been described in many publications.

[0042] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0043] The present invention will be described in detail below through embodiments.

[0044] In the embodiments and comparative examples of this invention, the contents of Li, Ni, Co and Mn were analyzed by ICP-OES (Agilent 725ES).

[0045] In the embodiments and comparative examples of this invention, the cathode material is derived from NCM532 ternary material, with Li content of 6.97%, Ni content of 28.86%, Co content of 11.78%, and Mn content of 15.63%.

[0046] The reagents used in the following examples are commercially available and of analytical grade.

[0047] Figure 1 This is a schematic diagram of the process flow for a method of resource utilization of waste ternary lithium-ion battery cathode material provided by the present invention. See also... Figure 1 As shown, the method of the present invention includes the following steps:

[0048] (1) The cathode material powder obtained from waste ternary lithium-ion batteries through conventional discharge, dismantling, crushing, and sieving is subjected to a hydrothermal displacement reaction in the presence of a displacement agent and water, followed by solid-liquid separation to obtain Li-rich materials. + Solutions and solids containing Ni, Co, and Mn elements;

[0049] (2) Rich in Li + The solution was further processed to obtain a Li-containing product;

[0050] (3) Solids containing Ni, Co and Mn elements are subjected to acid reduction and then subjected to hydrothermal reaction under pressure and temperature to obtain acid leaching solution that can be reused to prepare cathode materials.

[0051] Example 1

[0052] (1) 8g of positive electrode material powder (LiNi) 0.5 Co 0.2 Mn 0.3 O2 (containing 6.97wt% Li, 28.86wt% Ni, 11.78wt% Co, and 15.63wt% Mn) was placed in a 100mL pressure vessel, and 80mL of manganese sulfate aqueous solution was added, in which the molar ratio of Li to Mn was 10:5. The pressure vessel was then loaded into a homogeneous reactor and reacted at 160℃ for 12h under rotating conditions. The leaching rates of Li, Ni, Co, and Mn were 100%, 0%, 0%, and 0%, respectively.

[0053] (2) To enrich Li + The solution was evaporated and crystallized to obtain reagent-grade lithium sulfate.

[0054] (3) 16g of solid containing Ni, Co and Mn elements was placed in a 200mL pressure vessel, 150mL of 2mol / L sulfuric acid solution was added, and 10mL of hydrogen peroxide was slowly added dropwise. The slow reduction reaction was carried out at room temperature and pressure. After no more bubbles were produced, the vessel was covered and placed in a homogeneous reactor. The reaction was carried out at 140℃ for 2 hours under rotating conditions. The leaching rates of Ni, Co and Mn were all 100%, and there was no solid residue.

[0055] Example 2

[0056] (1) 8g of positive electrode material powder (LiNi) 0.5 Co0.2 Mn 0.3 O2 (containing 6.97 wt% Li, 28.86 wt% Ni, 11.78 wt% Co, and 15.63 wt% Mn) was placed in a 100 mL pressure vessel, along with 80 mL of water and a certain mass of basic cobalt carbonate (Li:Co molar ratio 10:10). The pressure vessel was then loaded into a homogeneous reactor and reacted at 200 °C for 12 h under rotating conditions. The leaching rates of Li, Ni, Co, and Mn were 60%, 0%, 0%, and 0%, respectively. Under the same experimental conditions, the leaching residue was subjected to a second leaching, and the total leaching rates of Li, Ni, Co, and Mn were 99.5%, 0%, 0%, and 0%, respectively.

[0057] (2) To enrich Li + The solution was concentrated to 30 g / L, and a saturated sodium carbonate solution was added dropwise at a reaction temperature of 90 °C. The resulting lithium carbonate was filtered, washed, and dried to obtain reagent-grade lithium carbonate product.

[0058] (3) 16g of solid containing Ni, Co and Mn elements was placed in a 200mL pressure vessel, 150mL of 2mol / L sulfuric acid solution was added, and 10mL of hydrazine hydrate was slowly added dropwise. The slow reduction reaction was carried out at room temperature and pressure. After no more bubbles were produced, the vessel was covered and placed in a homogeneous reactor. The reaction was carried out at 140℃ for 2h under rotating conditions. The leaching rates of Ni, Co and Mn were all 100%, and there was no solid residue.

[0059] Example 3

[0060] (1) 8g of positive electrode material powder (LiNi) 0.5 Co 0.2 Mn 0.3 O2 (containing 6.97wt% Li, 28.86wt% Ni, 11.78wt% Co, and 15.63wt% Mn) was placed in a 100mL pressure vessel, and 80mL of nickel nitrate aqueous solution was added, in which the molar ratio of Li to Mn was 10:5. The pressure vessel was then loaded into a homogeneous reactor and reacted at 180℃ for 16h under rotating conditions. The leaching rates of Li, Ni, Co, and Mn were 100%, 0%, 0%, and 0%, respectively.

[0061] (2) To enrich Li + The solution was evaporated and crystallized to obtain reagent-grade lithium sulfate.

[0062] (3) 16g of solid containing Ni, Co and Mn elements was placed in a 200mL pressure vessel, 130mL of 5mol / L nitric acid solution was added, and 20mL of hydrogen peroxide was slowly added dropwise. The slow reduction reaction was carried out at room temperature and pressure. After no more bubbles were produced, the vessel was covered and placed in a homogeneous reactor. The reaction was carried out at 180℃ for 5h under rotating conditions. The leaching rates of Ni, Co and Mn were all 100%, and there was no solid residue.

[0063] Example 4

[0064] (1) 8g of positive electrode material powder (LiNi) 0.5 Co 0.2 Mn 0.3 O2 (containing 6.97wt% Li, 28.86wt% Ni, 11.78wt% Co, and 15.63wt% Mn) was placed in a 100mL pressure vessel, and 80mL of ammonium cobalt sulfate aqueous solution (containing Li, Mn, and NH4) was added. + The molar ratio of the components was 10:5:10. The pressure vessel was loaded into a homogeneous reactor and reacted at 160°C for 12 hours under rotating conditions. The leaching rates of Li, Ni, Co, and Mn were 100%, 0%, 0%, and 0%, respectively.

[0065] (2) To enrich Li + The solution was evaporated and crystallized to obtain reagent-grade lithium sulfate.

[0066] (3) 16g of solid containing Ni, Co and Mn elements was placed in a 200mL pressure vessel, 130mL of 5mol / L nitric acid solution was added, and 20mL of hydrogen peroxide was slowly added dropwise. The slow reduction reaction was carried out at room temperature and pressure. After no more bubbles were produced, the vessel was covered and placed in a homogeneous reactor. The reaction was carried out at 180℃ for 5h under rotating conditions. The leaching rates of Ni, Co and Mn were all 100%, and there was no solid residue.

[0067] Example 5

[0068] The cathode material powder was processed using the same method as in Example 1, the only difference being that the cathode material powder itself was different, specifically LiNi. 0.8 Co 0.1 Mn 0.1 O2. The results showed that the leaching rates of Li, Ni, Co, and Mn were 80%, 0%, 0%, and 10%, respectively. This indicates that a Li-containing solution could not be obtained with high selectivity.

[0069] Example 6

[0070] The cathode material powder was processed using the same method as in Example 1, the only difference being that the cathode material powder itself was different, specifically LiNi. 0.33 Co 0.33 Mn0.33 O2. The results showed that the leaching rates of Li, Ni, Co, and Mn were 80%, 20%, 5%, and 3%, respectively. This indicates that a Li-containing solution could not be obtained with high selectivity.

[0071] Comparative Example 1

[0072] (1) 8g of positive electrode material powder (Li 6.97%, Ni 28.86%, Co 11.78%, Mn 15.63%) was placed in a 100mL pressure vessel, 75mL of 2mol / L sulfuric acid solution was added, and 5mL of hydrogen peroxide was slowly added dropwise. The vessel was then covered and placed in a homogeneous reactor. The reaction was carried out at 140℃ for 2h under rotating conditions. The leaching rates of Li, Ni, Co and Mn were 91.6%, 94.7%, 84.8% and 100%, respectively. If a high-purity Li-containing product is required, a subsequent separation unit is needed, which will further increase the processing cost.

[0073] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for the resource utilization of ternary lithium-ion battery cathode materials, comprising the following steps: (1) The cathode material powder from waste ternary lithium-ion batteries was subjected to a hydrothermal displacement reaction in the presence of a displacement agent and water, and Li-rich material was obtained by solid-liquid separation. + Solutions and solids containing Ni, Co, and Mn elements; (2) Rich in Li + The solution was further processed to obtain a Li-containing product; (3) A solid containing Ni, Co, and Mn elements is subjected to acid reduction followed by a hydrothermal reaction to obtain an acid leaching solution. Step (4) The acid leaching solution is recycled for the preparation of cathode materials; The displacement agent contains cations and anions. The cations include metal cations and / or NH4. + ; The metal cation is selected from Ni. 2+ Co 2+ Mn 2+ At least one of them; The anion is selected from SO4. 2- NO3 - CO3 2- HCO3 - (OH)2CO3 2- or Cl - At least one of them; The temperature of the hydrothermal replacement reaction is 120 ℃-250 ℃, and the time of the hydrothermal replacement reaction is 3 h-24 h.

2. The method according to claim 1, characterized in that, The displacement agent is selected from water-soluble displacement agents or non-water-soluble displacement agents.

3. The method according to claim 2, characterized in that, Li in the positive electrode material powder + The molar ratio of the metal cation in the water-soluble replacement agent is 10:(1-6).

4. The method according to claim 2, characterized in that, Li in the positive electrode material powder + The molar ratio of the metal cation in the water-soluble replacement agent is 10:(3-5).

5. The method according to claim 2, characterized in that, Li in the positive electrode material powder + The molar ratio of the metal cation in the non-water-soluble replacement agent is 10:(1-20).

6. The method according to claim 2, characterized in that, Li in the positive electrode material powder + The molar ratio of the metal cation to the non-water-soluble replacement agent is 10:(8-12).

7. The method according to claim 2, characterized in that, Li in the positive electrode material powder + With water-soluble displacing agent NH4 + The molar ratio is 10:(1-20).

8. The method according to claim 2, characterized in that, Li in the positive electrode material powder + With water-soluble displacing agent NH4 + The molar ratio is 10:(5-20).

9. The method according to claim 1, characterized in that, The hydrothermal replacement reaction is carried out at a temperature of 140℃-180℃; and / or The hydrothermal replacement reaction takes 12 h-20 h; and / or The mass ratio of the positive electrode material powder to the volume ratio of water (solid-liquid ratio, g / mL) is less than 1 g / mL:1 g / mL.

10. The method according to claim 1, characterized in that, The mass ratio of the positive electrode material powder to the volume ratio of water (solid-liquid ratio, g / mL) is 1:2 g / mL - 1:10 g / mL.

11. The method according to claim 1, characterized in that, In step (3), the reducing agent used in the acid reduction includes hydrogen peroxide and / or hydrazine hydrate.

12. The method according to claim 11, characterized in that, The mass ratio (solid-liquid ratio, g / mL) of the solid containing Ni, Co, and Mn to the volume ratio (solid-liquid ratio, g / mL) of the reducing agent is 5:1 g / mL - 1:2 g / mL.

13. The method according to claim 1, characterized in that, The acid used in the acid reduction includes at least one of sulfuric acid, hydrochloric acid, or nitric acid.

14. The method according to claim 13, characterized in that, The mass ratio (solid-liquid ratio, g / mL) of the solid containing Ni, Co, and Mn elements to the volume ratio (solid-liquid ratio, g / mL) of the acid is 1:4 g / mL - 1:20 g / mL.

15. The method according to claim 13, characterized in that, The mass ratio (solid-liquid ratio, g / mL) of the solid containing Ni, Co, and Mn elements to the volume ratio (solid-liquid ratio, g / mL) of the acid is 1:8 g / mL - 1:15 g / mL.

16. The method according to claim 13, characterized in that, The acid contains H + The concentration is 3 mol / L-10 mol / L.

17. The method according to claim 1, characterized in that, The acid reduction is carried out at a temperature of 20℃-35℃.

18. The method according to claim 1, characterized in that, In step (3), the temperature of the hydrothermal reaction is 120℃-250℃; and / or The hydrothermal reaction time is 1 h to 20 h.

19. The method according to claim 1, characterized in that, The temperature of the hydrothermal reaction is 140 ℃-180 ℃.

20. The method according to claim 1, characterized in that, The hydrothermal reaction takes 2-5 hours.

21. The method according to claim 1, characterized in that, In step (1), cathode material powder is obtained by discharging, dismantling, crushing and sieving the waste ternary lithium-ion battery.

22. The method according to claim 1, characterized in that, In step (2), the post-processing includes evaporation crystallization or concentration followed by precipitation.

23. The method according to any one of claims 1-22, characterized in that, Based on the total weight of the cathode material powder, the weight content of Ni is 10%-30%, the weight content of Co is 5%-15%, the weight content of Mn is 10%-40%, and the weight content of Li is 2%-10%; and / or The cathode material powder is derived from LiNi x Co y Mn 1-x-y A ternary lithium-ion battery composed of O2, wherein the value of x ranges from 0.4 to 0.7 and the value of y ranges from 0.1 to 0.

25.

24. The application of the method according to any one of claims 1-23 in the preparation of ternary lithium-ion batteries.

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