A method for preparing high-voltage nickel-medium ternary cathode materials through co-regeneration of spent ternary lithium batteries

Abstract

This invention provides a method for the co-regeneration of waste ternary lithium batteries to prepare high-voltage nickel-based ternary cathode materials, comprising the following steps: S1: Take pretreated waste high-nickel and low-nickel ternary cathode materials, calculate and supplement metal and lithium sources according to the actual metal content ratio, and the total molar ratio of elements after mixing is Li:(Ni+Co+Mn)=1.0-1.1; S2: Add a composite flux containing lithium-ion metal salts to the calibration mixture obtained in S1, and perform two-stage sintering; S3: Use the aqueous solution of the metal oxide corresponding to the lithium-ion metal salts in S2 as a coating agent to coat the surface of the final product to obtain the ternary cathode material. This invention utilizes the nickel-rich characteristics of high-nickel materials and the manganese / cobalt-rich characteristics of low-nickel materials to form elemental complementarity, thereby maximizing the utilization rate of nickel, manganese, and cobalt elements in waste materials and breaking through the composition ratio limitations of single waste recycling.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and in particular to a method for preparing high-voltage nickel-based ternary cathode materials through the co-regeneration of waste ternary lithium batteries. Background Technology

[0002] With the development of the new energy industry, the recycling and regeneration of waste nickel cobalt manganese oxide (NCM) ternary cathode materials has become a key to resource circulation, such as high-nickel NCM811 and low-nickel NCM523. However, the existing recycling process has two major bottlenecks.

[0003] Firstly, the imbalance in elemental ratios directly leads to poor cycle performance. High-nickel waste materials suffer severe lithium loss after recycling (Li vacancies ≥ 15%), while low-nickel materials experience a transition metal imbalance due to manganese leaching (Mn loss rate > 10%). For example, the existing patent CN113998742A discloses a method for recycling nickel-cobalt-manganese ternary lithium batteries. Although this patent improves the Al element distribution through a complexing agent, it does not completely solve the problem of elemental imbalance, resulting in a capacity retention rate of < 80% after 200 cycles of recycled materials. Furthermore, its embodiments show that adjusting the molar ratio of Ni, Co, and Mn ions to 5:2:3 only applies to the treatment of low-nickel waste materials alone.

[0004] Secondly, high-temperature sintering leads to structural degradation. Traditional recycling processes require high-temperature lithium replenishment and reheating, which exacerbates lithium volatilization (mass loss > 8%) and cation mixing (mixing degree > 6%). It also causes high-nickel materials to transform from layered to spinel phase, and low-nickel materials to form rock salt phase due to manganese migration, collectively resulting in the initial efficiency of recycled materials being < 85% and voltage plateau decay. For example, patent CN119764642A discloses a method for preparing recycled high-nickel ternary materials. After determining the content of lithium, nickel, cobalt, and manganese in the precursor, lithium carbonate is added at a ratio of Li:(Ni+Co+Mn) = 1~1.05:1 to supplement lithium. The material is then placed in a tube furnace and heated to 850°C at a rate of 5°C / min, followed by calcination in a flowing oxygen atmosphere for 15 hours to obtain the ternary cathode material. This sintering method optimizes the sintering process through slow heating, oxygen atmosphere, and lithium excess design, but its high temperature still easily leads to the release of small amounts of lithium. + Volatilization and cation mixing.

[0005] Meanwhile, existing recycling processes suffer from low nickel-lithium recovery rates in high-nickel recovery and difficulty in extracting lithium from low-nickel recovery. Existing patent CN116287726A discloses a method for treating high-nickel matte leaching residue. This method involves feeding high-nickel matte leaching residue and low-nickel matte in a proportionate manner into a reduction furnace, where natural gas and oxygen-enriched air are injected to react and generate secondary medium-nickel matte, thereby improving the recovery rate of nickel, cobalt, and precious metals. While this method provides a way to obtain medium-nickel by mixing high and low nickel, it only targets high-nickel matte leaching residue, a byproduct of primary nickel ore smelting. This residue differs significantly from the morphology, impurity composition, and metal occurrence state of waste battery electrode materials, making it impractical for the waste battery recycling field.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a method for preparing high-voltage, medium-nickel ternary cathode materials through the co-regeneration of spent ternary lithium batteries.

[0008] This invention provides a method for preparing high-voltage nickel-based ternary cathode materials through the co-regeneration of spent ternary lithium batteries, comprising the following steps:

[0009] S1: Take the pretreated waste high-nickel and low-nickel ternary cathode materials as starters for later use. Calculate and supplement non-lithium metal sources according to the target ratio of Ni, Co, and Mn in the medium-nickel ternary cathode material. Supplement lithium sources according to the total molar ratio of elements after mixing the two starters, which is Li:(Ni+Co+Mn)=1.0-1.1, to obtain a calibration mixture.

[0010] S2: Add a certain amount of composite flux containing lithium ion metal salt to the calibration mixture obtained in S1, mix evenly, and then perform two-stage sintering under oxygen-rich and negative pressure conditions to obtain the final product.

[0011] S3: Using the aqueous solution of the metal oxide corresponding to the lithium-ion metal salt involved in S2 as a coating agent, the surface of the final product is coated to obtain a ternary cathode material.

[0012] In an exemplary embodiment of the present invention, in step S1, the nickel metal ratio in the calibration mixture is in the range of 0.8 ≤ Ni / (Ni+Co+Mn) < 1.

[0013] In an exemplary embodiment of the present invention, in step S1, the nickel metal ratio in the calibration mixture is in the range of 0.3 ≤ Ni / (Ni+Co+Mn) < 0.8.

[0014] In an exemplary embodiment of the present invention, in step S1, the metal source is one or more combinations of nickel acetate, cobalt acetate, and manganese acetate, and the lithium source is one or more combinations of lithium carbonate, lithium hydroxide, and lithium oxalate.

[0015] In an exemplary embodiment of the present invention, in step S2, the composite flux is a composite of fluoride and lithium-ion metal salt, wherein the mass ratio of fluoride to lithium-ion metal salt is 1:0.4-0.6.

[0016] In an exemplary embodiment of the present invention, the fluoride is one or more of lithium fluoride, aluminum fluoride, and yttrium fluoride, and the lithium-ion metal salt is one or more of lithium fluoride, lithium titanate, lithium tungstate, lithium aluminate, lithium titanate, lithium phosphate, and lithium titanium aluminum phosphate.

[0017] In an exemplary embodiment of the present invention, in step S2, 1000-5000 ppm of a composite flux containing lithium-ion metal salt is added to the calibration mixture obtained in S1. The two-stage sintering process is as follows: under oxygen-rich and negative pressure conditions, the temperature is increased to 200-400°C at 3-5°C / min and held for 4-6 hours; the temperature is increased to 650-750°C at 1-3°C / min and held for 10-15 hours.

[0018] In an exemplary embodiment of the present invention, in step S2, the oxygen-enriched condition is an oxygen content greater than 80%.

[0019] In an exemplary embodiment of the present invention, the negative pressure condition in step S2 is -100 to -300 Pa.

[0020] In an exemplary embodiment of the present invention, in step S3, 1000-3000 ppm of coating agent is coated on the surface of the final product through an atomizing nozzle and the two are mixed evenly at 300-1000 rpm. The temperature is increased to 400-500°C at 2-5°C / min and kept at the temperature for 6-8 hours.

[0021] The beneficial effects of the method for preparing high-voltage nickel-based ternary cathode materials through the co-regeneration of spent ternary lithium batteries according to embodiments of the present invention are as follows:

[0022] 1. This invention utilizes the nickel-rich characteristics of high-nickel materials and the manganese / cobalt-rich characteristics of low-nickel materials to form elemental complementarity, maximizing the utilization rate of nickel, manganese, and cobalt elements in waste materials and breaking through the component ratio limitations of single waste recycling. Furthermore, nickel in waste high-nickel materials mostly exists as non-layered phases such as spinel or rock salt, while waste low-nickel materials can provide a sufficient manganese source. Co-recycling of both can significantly reduce the proportion of non-layered nickel in the final product, optimizing the material's phase composition.

[0023] 2. This invention employs a composite flux (such as a yttrium fluoride and lithium titanate composite system), which can significantly reduce the sintering temperature and effectively avoid lithium volatilization loss caused by the high-temperature lithium replenishment process in traditional materials. Simultaneously, this flux can drive the complementary elemental reconstruction of waste high-nickel and low-nickel materials, promote intergranular liquid phase diffusion, significantly reduce grain boundary defects, and improve the microstructural stability of the material.

[0024] 3. This invention innovatively employs a semi-wet coating layer and a composite flux to synergistically construct a surface-bulk integrated modification system. This system can effectively suppress side reactions between the electrolyte and electrode materials, enabling the materials to maintain excellent cycle stability under high-voltage conditions and extending battery life.

[0025] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram illustrating the regeneration principle of the method for preparing high-voltage nickel-medium ternary cathode material through the co-regeneration of waste ternary lithium batteries according to an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions in the embodiments of this disclosure will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0029] The following is a detailed description of the method for preparing high-voltage nickel-medium ternary cathode material by co-regeneration of waste ternary lithium batteries according to an embodiment of the present invention.

[0030] See appendix Figure 1 This invention provides a method for preparing high-voltage nickel-based ternary cathode materials through the co-regeneration of spent ternary lithium batteries, comprising the following steps:

[0031] S1: Take the pretreated waste high-nickel and low-nickel ternary cathode materials as starters for later use. Calculate and supplement non-lithium metal sources according to the target ratio of Ni, Co, and Mn in the medium-nickel ternary cathode material. Supplement lithium sources according to the total molar ratio of elements after mixing the two starters, which is Li:(Ni+Co+Mn)=1.0-1.1, to obtain a calibration mixture.

[0032] Further, in a preferred embodiment of the present invention, the pretreatment includes mechanically crushing the waste high-nickel and low-nickel ternary cathode materials respectively, removing aluminum foil residue by sieving through a 150-400 mesh sieve, and then washing with an ethanol-oxalic acid mixed solution to remove surface binders and impurities to obtain the starting materials. The actual contents of Ni, Co, Mn, and Li in the two starting materials are then determined.

[0033] Furthermore, in a preferred embodiment of the present invention, in step S1, the nickel metal ratio in the calibration mixture is in the range of 0.8 ≤ Ni / (Ni+Co+Mn) < 1.

[0034] Furthermore, in another embodiment of the present invention, in step S1, the nickel metal ratio in the calibration mixture is in the range of 0.3 ≤ Ni / (Ni+Co+Mn) < 0.8.

[0035] Furthermore, in a preferred embodiment of the present invention, in step S1, the metal source is one or more combinations of nickel acetate, cobalt acetate, and manganese acetate, and the lithium source is one or more combinations of lithium carbonate, lithium hydroxide, and lithium oxalate.

[0036] Furthermore, in a preferred embodiment of the present invention, the fluoride is one or more of lithium fluoride, aluminum fluoride, and yttrium fluoride, and the lithium-ion metal salt is one or more of lithium fluoride, lithium titanate, lithium tungstate, lithium aluminate, lithium titanate, lithium phosphate, and lithium titanium aluminum phosphate.

[0037] S2: Add a composite flux containing lithium-ion metal salt to the calibration mixture obtained in S1, mix evenly, and then perform a two-stage sintering process under oxygen-rich and negative pressure conditions to obtain the final product.

[0038] Furthermore, in a preferred embodiment of the present invention, in step S2, the composite flux is a composite of fluoride and lithium-ion metal salt, wherein the mass ratio of fluoride to lithium-ion metal salt is 1:0.4-0.6.

[0039] Further, in a preferred embodiment of the present invention, in step S2, 1000-5000 ppm of a composite flux containing lithium-ion metal salt is added to the calibration mixture obtained in S1, such as 1000 ppm, 1500 ppm, 2500 ppm, 3500 ppm, 5000 ppm, etc., but not limited thereto. The two-stage sintering process is as follows: under oxygen-rich, negative pressure conditions, the temperature is increased to 200-400°C at a rate of 3-5°C / min, for example, the heating rate can be 3°C / min, 3.5°C / min, 4°C / min, 5°C / min, etc., and the temperature is increased to 200°C, 250°C, 300°C, 400°C, etc., but not limited thereto. The holding time for the first sintering is 4-6 hours, such as 4h, 4.5h, 5h, 6h, etc., but not limited thereto. For secondary sintering, the temperature is increased to 650-750℃ at a rate of 1-3℃ / min and held for 10-15 hours. The same principle applies to secondary sintering, and the values ​​can be taken within a limited range, not limited to the endpoints.

[0040] Furthermore, in a preferred embodiment of the present invention, in step S2, the oxygen-enriched condition is an oxygen content greater than 80%.

[0041] Furthermore, in a preferred embodiment of the present invention, the negative pressure condition in step S2 is -100 to -300 Pa. For example, the negative pressure condition is -110 Pa, -220 Pa, -250 Pa, -300 Pa, etc., but is not limited to this.

[0042] S3: Using the aqueous solution of the metal oxide corresponding to the lithium-ion metal salt involved in S2 as a coating agent, the surface of the final product is coated to obtain a ternary cathode material.

[0043] Further, in a preferred embodiment of the present invention, in step S3, 1000-3000 ppm of a coating agent is coated onto the surface of the final product using an atomizing nozzle, and the two are mixed uniformly at 300-1000 rpm. The temperature is then increased to 400-500°C at 2-5°C / min and held for 6-8 hours. The coating agent can be, for example, 1000 ppm, 1400 ppm, 1500 ppm, 2500 ppm, 3000 ppm, etc., but is not limited to these. The heating rate can be, for example, 2°C / min, 3°C / min, 3.5°C / min, 5°C / min, etc., but is not limited to these. The holding time can be, for example, 6 hours, 6.5 hours, 7 hours, 8 hours, etc., but is not limited to these.

[0044] This invention also provides a lithium-ion battery, comprising a positive electrode, a negative electrode, and an electrolyte, wherein the positive electrode comprises the aforementioned high-voltage nickel ternary positive electrode material. It is understood that this lithium-ion battery can be manufactured according to known methods in the prior art.

[0045] The features and performance of the present invention will be further described in detail below with reference to embodiments. Example 1

[0046] This embodiment provides a method for preparing high-voltage, medium-nickel ternary cathode materials through the co-regeneration of spent ternary lithium batteries, which is carried out according to the following steps:

[0047] S1: Waste high-nickel NCM811 and low-nickel NCM523 ternary cathode materials were mechanically crushed and sieved through a 400-mesh sieve to remove aluminum foil residue. Then, they were cleaned with an ethanol-oxalic acid mixed solution (0.5 mol / L) to remove surface binders and impurities, yielding the starting materials. The actual contents of Ni, Co, Mn, and Li in the two starting materials were determined. Based on the target nickel ratio (NCM622), the required metal source (nickel acetate / cobalt / manganese) and lithium source (lithium hydroxide) were calculated and prepared to a ratio of Ni:(Ni+Co+Mn)=0.6. Missing elements were supplemented, and the total molar ratio was adjusted to Li:(Ni+Co+Mn)=1.05 to obtain the calibration mixture.

[0048] In this embodiment, although the Ni content of high-nickel NCM811 and low-nickel NCM523 can be controlled by mixing, in actual recycling, the actual Ni / Co / Mn ratio of the waste material may deviate from the theoretical value due to wear and tear. Simply mixing the two types of waste NCM is not sufficient to directly achieve the target ratio of NCM622 (Ni:Co:Mn=6:2:2). Therefore, by calculating the actual content, it is determined which metal (such as one or more of nickel, cobalt, and manganese) is insufficient. Then, its corresponding acetate is added to fill the gap, ensuring that the elemental ratio of the final mixed system fully meets the requirements.

[0049] S2: Add 5000ppm of composite flux (yttrium fluoride + lithium titanate, mass ratio 1:0.4), and then carry out a two-stage sintering process: under oxygen-rich conditions, i.e. oxygen content greater than 80%, and negative pressure (-200Pa), heat up to 300℃ at 3-5℃ / min and hold for 5 hours; heat up to 750℃ at 1-3℃ / min and hold for 10 hours to obtain the final product.

[0050] S3: Using titanium dioxide as a coating agent, 1000ppm is coated on the surface of the final product through an atomizing nozzle, and the temperature is increased to 450℃ at 2℃ / min and held for 6h to obtain a ternary cathode material. Example 2

[0051] This embodiment provides a method for preparing high-voltage nickel-based ternary cathode materials through the co-regeneration of waste ternary lithium batteries. The difference between this method and Example 1 is that: in step S2, 3000ppm of composite flux (lithium fluoride + lithium tungstate, mass ratio 1:0.6) is added, and in step S3, tungsten trioxide is used as a coating agent to coat the surface of the final product with 2000ppm of flux through an atomizing nozzle.

[0052] The remaining steps are the same as in Example 1. Example 3

[0053] This embodiment provides a method for preparing high-voltage nickel-based ternary cathode material through co-regeneration of waste ternary lithium batteries. The difference between this method and Example 1 is that: in step S2, 1000ppm of composite flux (aluminum fluoride + lithium aluminate, mass ratio 1:0.4) is added, and in step S3, alumina is used as a coating agent to coat the surface of the final product with 1000ppm of flux through an atomizing nozzle.

[0054] The remaining steps are the same as in Example 1.

[0055] Comparative Example 1

[0056] This embodiment provides a method for preparing high-voltage nickel-based ternary cathode material through co-regeneration of waste ternary lithium batteries. The difference between this method and Embodiment 1 is that: in step S2, no composite flux or other fluxing agent is added, and the coating in step S3 is no longer performed. The final product in step S2 is directly used as the final ternary cathode material.

[0057] The remaining steps are the same as in Example 1.

[0058] Comparative Example 2

[0059] This embodiment provides a method for preparing high-voltage nickel-based ternary cathode materials through the co-regeneration of waste ternary lithium batteries. The difference between this method and Embodiment 1 is that: in step S2, no composite flux or other fluxing agents are added; and in step S3, titanium dioxide is used as a coating agent to coat the surface of the final product with 1000ppm of the coating agent through an atomizing nozzle.

[0060] The remaining steps are the same as in Comparative Example 1.

[0061] Comparative Example 3

[0062] This embodiment provides a method for preparing high-voltage nickel-based ternary cathode material through co-regeneration of waste ternary lithium batteries. The difference between this method and Example 1 is that 5000ppm of composite flux (yttrium fluoride + lithium titanate, mass ratio 1:0.4) is added in step S2, and the coating in step S3 is no longer performed. The final product in step S2 is directly used as the final ternary cathode material.

[0063] The remaining steps are the same as in Example 1.

[0064] Comparative Example 4

[0065] This embodiment provides a method for preparing high-voltage nickel-based ternary cathode materials through the co-regeneration of waste ternary lithium batteries. The difference between this method and Example 1 is that the composite flux (yttrium fluoride + lithium titanate, mass ratio 1:0.4) is replaced with a single flux (lithium fluoride).

[0066] The remaining steps are the same as in Example 1.

[0067] Comparative Example 5

[0068] This embodiment provides a method for preparing high-voltage nickel-based ternary cathode materials through the co-regeneration of waste ternary lithium batteries. The difference between this method and Example 1 is that the 5000ppm composite flux (yttrium fluoride + lithium titanate, mass ratio 1:0.4) is replaced with 2000ppm flux (lithium titanate).

[0069] The remaining steps are the same as in Example 1.

[0070] Comparative Example 6

[0071] This embodiment provides a method for preparing high-voltage nickel-based ternary cathode materials through the co-regeneration of waste ternary lithium batteries. The difference between this method and Embodiment 1 is that titanium dioxide is replaced with aluminum oxide in step S3.

[0072] The remaining steps are the same as in Example 1.

[0073] Basic performance analysis

[0074] The determination and analysis of the discharge specific capacity and 50-cycle capacity retention of the high-voltage nickel ternary cathode materials prepared in Examples 1-3 and Comparative Examples 1-6 are shown in Table 1:

[0075] Table 1

[0076] Implementation status Main implementation features 4.45V / 0.5C discharge capacity, mAh / g 50-cycle capacity retention rate / % Example 1 5000ppm composite flux (yttrium fluoride + lithium titanate) + 1000ppm coating agent (titanium dioxide) 190.5 96.24 Example 2 3000ppm composite flux (lithium fluoride + lithium tungstate) + 2000ppm coating agent (tungsten trioxide) 189.2 95.17 Example 3 1000ppm composite flux (aluminum fluoride + lithium aluminate) + 1000ppm coating agent (alumina) 190.3 97.01 Comparative Example 1 No flux, no coating 175.3 70.18 Comparative Example 2 Flux-free, +1000ppm coating agent (titanium dioxide) 176.0 71.32 Comparative Example 3 5000ppm composite flux (yttrium fluoride + lithium titanate), uncoated 184.9 79.79 Comparative Example 4 5000ppm single flux (lithium fluoride) + 1000ppm coating agent (titanium dioxide) 183.6 90.13 Comparative Example 5 2000ppm other flux (lithium titanate) + 1000ppm coating agent (titanium dioxide) 180.1 88.47 Comparative Example 6 5000ppm composite flux (yttrium fluoride + lithium titanate) + 1000ppm coating agent (non-corresponding metal oxide: aluminum oxide) 186.4 93.37

[0077] As shown in Table 1, comparing the data of Examples 1-3 with those of Comparative Examples 1-3, it can be determined that the synergistic use of composite flux and coating agent in this invention is crucial for improving the electrochemical performance of high-voltage nickel ternary cathode materials. In terms of discharge capacity, Examples 1 (190.5 mAh / g), 2 (189.2 mAh / g), and 3 (190.3 mAh / g) containing flux and coating agent are significantly higher than the groups without flux (Comparative Example 1: 175.3 mAh / g, Comparative Example 2: 176.0 mAh / g) and the group with flux alone (Comparative Example 3: 184.9 mAh / g). This indicates that the flux can optimize the material's crystal structure and promote ion conduction, while the coating agent further reduces interfacial impedance; the synergistic effect of both increases the capacity by 10%-8%. The differences were even more significant in terms of capacity retention after 50 cycles: Example 1 (96.24%), Example 2 (95.17%), and Example 3 (97.01%) were far superior to Comparative Example 1 (70.18%), Comparative Example 2 (71.32%), and Comparative Example 3 (79.79%). This indicates that the flux can inhibit particle growth and reduce lithium loss, while the coating agent can prevent electrolyte erosion; the combination of the two significantly improves cycle stability.

[0078] Furthermore, a comparison of Examples 1, 2, and 3 shows that the type of flux (yttrium fluoride + lithium titanate or lithium fluoride + lithium tungstate or aluminum fluoride + lithium aluminate) and the amount of coating agent (1000ppm or 2000ppm) have little impact on performance, and the core remains the synergistic system of "flux + coating agent". However, Comparative Examples 2-3 demonstrate that using coating agent or flux alone has limited effect on improving cycle stability, and only synergistic use can achieve a performance breakthrough.

[0079] In summary, the composite flux used in this invention can significantly reduce the sintering temperature and effectively avoid lithium volatilization loss caused by the high-temperature lithium replenishment process in traditional materials. Simultaneously, this flux can drive the complementary elemental composition reconstruction of waste high-nickel and low-nickel materials, promote intergranular liquid-phase diffusion, significantly reduce grain boundary defects, and improve the microstructural stability of the material. Furthermore, the composite flux and the semi-wet coating layer work synergistically to construct a surface-bulk integrated modification system, which can stably suppress side reactions between the electrolyte and electrode materials, enabling the material to maintain excellent cycle stability under high-voltage conditions and extend battery life.

[0080] The above description does not cover all embodiments. The detailed description of embodiments in this disclosure is not intended to limit the scope of the claimed disclosure, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in this disclosure without inventive effort are within the scope of protection of this disclosure.

Claims

1. A method for preparing high-voltage, medium-nickel ternary cathode materials through co-regeneration of spent ternary lithium batteries, characterized in that, Includes the following steps: S1: Take the pretreated waste high-nickel and low-nickel ternary cathode materials as starters for later use. Measure the actual content of Ni, Co, Mn and Li in the two starters. Calculate and supplement non-lithium metal sources according to the target ratio of Ni, Co and Mn in the medium-nickel ternary cathode material. Supplement lithium sources according to the total molar ratio of elements after mixing the two starters, which is Li:(Ni+Co+Mn)=1.0-1.1, to obtain a calibration mixture. S2: Add a certain amount of composite flux containing lithium-ion metal salt to the calibration mixture obtained in S1, mix evenly, and then perform a two-stage sintering treatment under oxygen-rich and negative pressure conditions to obtain the final product. The composite flux is a complex of fluoride and lithium-ion metal salt, and the mass ratio of fluoride to lithium-ion metal salt is 1:0.4-0.

6. S3: Using the aqueous solution of the metal oxide corresponding to the lithium-ion metal salt involved in S2 as a coating agent, the surface of the final product is coated to obtain a ternary cathode material.

2. The method for preparing high-voltage nickel-based ternary cathode materials through co-regeneration of spent ternary lithium batteries as described in claim 1, characterized in that... In step S1, the metal source is one or more combinations of nickel acetate, cobalt acetate, and manganese acetate, and the lithium source is one or more combinations of lithium carbonate, lithium hydroxide, and lithium oxalate.

3. The method for preparing high-voltage nickel-medium ternary cathode material through co-regeneration of waste ternary lithium batteries as described in claim 1, characterized in that, The fluoride is one or more of lithium fluoride, aluminum fluoride, and yttrium fluoride, and the lithium-ion metal salt is one or more of lithium fluoride, lithium titanate, lithium tungstate, lithium aluminate, lithium phosphate, and lithium titanium aluminum phosphate.

4. The method for preparing high-voltage nickel-medium ternary cathode material through co-regeneration of waste ternary lithium batteries as described in claim 1, characterized in that, In step S2, 1000-5000 ppm of a composite flux containing lithium-ion metal salts is added to the calibration mixture obtained in S1. The two-stage sintering process is as follows: under oxygen-rich and negative pressure conditions, the temperature is increased to 200-400℃ at 3-5℃ / min and held for 4-6 hours. Increase the temperature to 650-750℃ at a rate of 1-3℃ / min and hold for 10-15 hours.

5. The method for preparing high-voltage nickel-medium ternary cathode material through co-regeneration of waste ternary lithium batteries as described in claim 4, characterized in that, In step S2, the oxygen-enriched condition is that the oxygen content is greater than 80%.

6. The method for preparing high-voltage nickel-medium ternary cathode material through co-regeneration of waste ternary lithium batteries as described in claim 4, characterized in that, In step S2, the negative pressure condition is -100 to -300 Pa.

7. The method for preparing high-voltage nickel-based ternary cathode materials through co-regeneration of spent ternary lithium batteries as described in claim 1, characterized in that... In step S3, 1000-3000 ppm of coating agent is coated on the surface of the final product through an atomizing nozzle and the two are mixed evenly at 300-1000 rpm. The temperature is increased to 400-500℃ at 2-5℃ / min and kept at that temperature for 6-8 hours.

Images