Continuous synthesis preparation process for high-nickel ternary precursor of lithium battery

Abstract

The invention discloses a continuous synthesis preparation process for a high-nickel ternary precursor of a lithium battery. The continuous synthesis preparation process comprises the following steps: S1, raw material preparation: preparing a soluble mixed salt solution containing nickel, cobalt and manganese; preparing an alkali solution as a precipitator; preparing a mixed solution containing ammonia water and a green complexing agent as a complexing agent; s2, metering and mixing: quantitatively mixing the mixed salt solution, the alkali solution and the complexing agent solution through a metering system; the spatial separation of crystal nucleation and growth is realized through the multistage tandem reaction kettles, so that the product has the advantages of narrow particle size distribution, good sphericity degree, high tap density and the like; meanwhile, an accurate online monitoring and control system ensures the high consistency of product batches; and by combining an efficient resource recovery process, the production cost and the environmental influence are remarkably reduced while the product quality is improved, and the process is very suitable for industrial large-scale production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of preparation of lithium ion battery cathode material precursor, and particularly relates to a continuous synthesis preparation process for lithium battery high-nickel ternary precursor. BACKGROUND

[0002] With the rapid development of new energy vehicles, energy storage and other fields, higher requirements are put forward for the performance of lithium ion batteries such as energy density and cycle life; and high-nickel ternary cathode material has become a research hotspot of current lithium ion battery cathode material due to its high specific capacity, low cost and other advantages. The performance of high-nickel ternary precursor directly determines the performance of the final cathode material, therefore, it is crucial to develop an efficient and stable high-nickel ternary precursor preparation process.

[0003] At present, the coprecipitation method is a commonly used method for preparing high-nickel ternary precursor, mainly including a sulfate coprecipitation system, a carbonate coprecipitation system and an oxalate coprecipitation system; among them, the sulfate coprecipitation system is the most widely used; in the preparation process, there are continuous and intermittent synthesis methods.

[0004] However, the continuous synthesis has high yield and simple operation, but has problems such as uneven particle size distribution and poor sphericity of the product; the intermittent synthesis has uniform precursor particles, narrow diameter distance, but has problems such as frequent start-stop, low yield and the like; in addition, the existing process still has deficiencies in controlling key performance indicators such as precursor particle size, morphology and crystallinity, and it is difficult to meet the strict requirements of high-performance lithium ion batteries on high-nickel ternary cathode materials. SUMMARY

[0005] The present application aims to at least solve one of the technical problems in the related art to some extent.

[0006] To this end, the present application proposes a continuous synthesis preparation process for lithium battery high-nickel ternary precursor, which successfully solves the problems of poor product consistency and low batch stability in traditional intermittent production, and effectively improves the cycle performance and safety performance of high-nickel ternary cathode material through a multi-stage series reaction system, online real-time monitoring and closed-loop control, and optional gradient structure design; the method has high production efficiency, low cost and environmental friendliness, and is very suitable for industrialized mass production of high-performance high-nickel ternary precursor.

[0007] To achieve the above purpose, the present application proposes a continuous synthesis preparation process for lithium battery high-nickel ternary precursor, comprising the following steps: S1, raw material preparation: preparing a soluble mixed salt solution containing nickel, cobalt and manganese; preparing an alkali solution as a precipitant; preparing a mixed solution containing ammonia and a green complexing agent as a complexing agent; S2, metering and mixing: the mixed salt solution, alkali solution and complexing agent solution are quantitatively mixed by a metering system; S3, precipitation reactor: the mixed liquid in S2 is continuously and flowingly introduced into a reaction system composed of at least three reactors connected in series; under the protection of inert gas, the reaction conditions are controlled to carry out the coprecipitation reaction to generate ternary precursor slurry; wherein the first reactor mainly controls the formation of crystal nucleus, and the second and subsequent reactors mainly control the growth of crystal nucleus; S4, aging reactor: the slurry after the coprecipitation reaction in S3 is continuously overflowed into the aging reactor for aging; S5, solid-liquid separation: the aged slurry is sequentially subjected to continuous solid-liquid separation, washing, drying and screening to obtain high-nickel ternary precursor product; S6, wastewater treatment and valuable metal recovery: the mother liquor and washing liquid generated by solid-liquid separation are treated to recover the alkali and metal salt therein for solution preparation in S1.

[0008] In addition, the continuous synthesis and preparation process for high-nickel ternary precursor of lithium battery according to the above-mentioned application can also have the following additional technical features: Specifically, in S1, high-purity nickel sulfate, cobalt sulfate and manganese sulfate are selected as metal salt raw materials, and are accurately weighed according to the required molar ratio of nickel, cobalt and manganese, and are dissolved into a mixed salt solution with pure water, and the total metal concentration is controlled to be 2.0 mol / L; at the same time, 32% liquid alkali is prepared and diluted with pure water to 6 mol / L as a precipitant; 25% ammonia water is prepared and diluted to 10% as a complexing agent.

[0009] Specifically, in S2, a metering pump is provided for accurately controlling the feed flow of the mixed salt solution, precipitant and complexing agent.

[0010] Specifically, in S3, the inert gas is high-purity nitrogen as the protective gas, and the purity is ≥99.95%.

[0011] Specifically, in S3, a multi-stage series reactor is used, and each reactor is provided with an independent stirring device, a heating device, a temperature sensor, a pH sensor, an ammonia concentration sensor and an online particle size monitor.

[0012] Specifically, in S3, three or more series reactors are used to realize the spatial separation of crystal nucleation and growth.

[0013] Specifically, the first reactor strictly controls the supersaturation to promote uniform nucleation; the subsequent reactors provide a stable growth environment to ensure the dense growth of the crystal and reduce structural defects.

[0014] Specifically, the S3 is to form the element concentration gradient distribution or the porosity gradient distribution in the obtained precursor particles by adjusting the molar ratio of nickel, cobalt and manganese in the mixed salt solution or adjusting the complexing agent concentration in stages during the co-precipitation reaction.

[0015] Specifically, the control conditions of the first reactor in the S3 are as follows: pH value 11.0-12.0, temperature 50-60 DEG C, stirring speed 400-600 rpm; and the control conditions of the subsequent reactors are as follows: pH value 10.5-11.5, temperature 55-65 DEG C, stirring speed 300-500 rpm.

[0016] Specifically, the mother liquor and the washing liquid in the S6 are sent to a wastewater treatment system to recover valuable metal salts, alkali and ammonia therefrom; and the recovered materials can be returned to the previous process for recycling, which meets the requirements of green environmental protection and cost reduction.

[0017] Compared with the prior art, the application has the following beneficial effects: The spatial separation of crystal nucleation and growth is realized by the multi-stage series connection of the reactors, so that the product has the advantages of narrow particle size distribution, good sphericity and high tap density; meanwhile, the accurate online monitoring and control system ensures the high consistency between batches of products. In combination with the efficient resource recovery process, the process can improve the product quality while significantly reducing the production cost and environmental impact, and is very suitable for industrial large-scale production.

[0018] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and / or additional aspects and advantages of the application will become apparent and be well understood from a review of the following description, taken in conjunction with the drawings, wherein: Figure 1 The process flow diagram of the application is shown in the following figure. DETAILED DESCRIPTION

[0020] The embodiments of the application are described in detail below with reference to the accompanying drawings, in which the same or similar components have the same reference numerals throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the application, and cannot be understood as limiting the application. On the contrary, the embodiments of the application include all changes, modifications and equivalents falling within the spirit and scope of the appended claims.

[0021] A continuous synthesis and preparation process for a high-nickel ternary precursor for lithium batteries is described below in conjunction with the accompanying drawings. EMBODIMENT

[0022] As Figure 1 shown, a continuous synthesis and preparation process for high-nickel ternary precursor of lithium battery according to an embodiment of the present application can include the following steps: S1, raw material preparation: prepare a soluble mixed salt solution containing nickel, cobalt and manganese; prepare an alkali solution as a precipitant; prepare a mixed solution containing ammonia and a green complexing agent as a complexing agent; S2, metering and mixing: the mixed salt solution, alkali solution and complexing agent solution are quantitatively mixed by a metering system; S3, precipitation reactor: the mixed liquid in S2 is continuously and flowingly passed into a reaction system composed of at least three reactors connected in series; under the protection of inert gas, the reaction conditions are controlled to carry out coprecipitation reaction to generate ternary precursor slurry; wherein the first reactor mainly controls the formation of crystal nucleus, and the second and subsequent reactors mainly control the growth of crystal nucleus; S4, aging tank: the slurry after coprecipitation reaction in S3 is continuously overflowed into an aging tank for aging; S5, solid-liquid separation: the aged slurry is sequentially subjected to continuous solid-liquid separation, washing, drying and screening to obtain high-nickel ternary precursor product; S6, wastewater treatment and valuable metal recovery: the mother liquor and washing liquid generated by solid-liquid separation are treated to recover the alkali and metal salt therein for solution preparation in S1.

[0023] In S1, high-purity nickel sulfate, cobalt sulfate and manganese sulfate are selected as metal salt raw materials, accurately weighed according to the required molar ratio of nickel, cobalt and manganese, and dissolved into a mixed salt solution with pure water, with the total metal concentration controlled at 2.0 mol / L; wherein the nickel sulfate, cobalt sulfate and manganese sulfate are prepared in a molar ratio of Ni:Co:Mn = 83:12:5 to prepare a mixed salt solution with a total metal ion concentration of 2 mol / L; at the same time, 32% liquid alkali is prepared, and the liquid alkali is sodium hydroxide solution, and the sodium hydroxide solution is diluted with pure water to 6 mol / L as a precipitant; 25% ammonia water is prepared and diluted to 10%, and potassium sodium tartrate is added, and the concentration of potassium sodium tartrate is 0.1 mol / L mixed solution as a complexing agent.

[0024] In S2, a metering pump is provided for accurately controlling the feed flow of the mixed salt solution, the precipitant and the complexing agent; the above three solutions are respectively delivered to the subsequent reaction system by the precision metering pump at a set flow rate, and the feed flow ratio of the mixed salt solution, the alkali solution and the complexing agent solution is accurately linked and controlled by feedback from the online pH meter and ammonia concentration meter in the reaction kettle, so that the ternary precursor slurry can be obtained.

[0025] In S3, the inert gas is high-purity nitrogen as a protective gas with a purity of ≥99.95%. Therefore, high-purity nitrogen can be used to ensure that the mixed salt solution, precipitant and complexing agent undergo a full and stable mixing reaction in the first reactor in S3.

[0026] The S3 uses multi-stage series reactors, each equipped with an independent stirring device, heating device, temperature sensor, pH sensor, ammonia concentration sensor and online particle size monitor. Therefore, it can realize real-time monitoring of the pH value, temperature and solid content in each reactor, and feed the monitoring data back to the central control system to dynamically adjust the feed flow rate and stirring intensity of each solution to ensure stable reaction conditions.

[0027] S3 employs three or more reactors in series to achieve spatial separation of crystal nucleation and growth; the first reactor strictly controls supersaturation to promote uniform nucleation; subsequent reactors provide a stable growth environment to ensure dense crystal growth and reduce structural defects.

[0028] In the coprecipitation reaction, S3 adjusts the molar ratio of nickel, cobalt, and manganese in the mixed salt solution or adjusts the concentration of the complexing agent in stages to form an elemental concentration gradient distribution or a porosity gradient distribution inside the resulting precursor particles. Therefore, by precisely controlling the composition of the feed liquid in different reaction stages in the reactor, precursor particles with a core-shell structure or concentration gradient can be prepared. This structure helps to suppress the generation of microcracks during the charge and discharge process and improve the cycle stability and safety of the material.

[0029] Meanwhile, the control conditions for the first reactor in S3 are: pH value 11.0-12.0, temperature 50-60℃, and stirring speed 400-600rpm; the control conditions for the subsequent reactors are: pH value 10.5-11.5, temperature 55-65℃, and stirring speed 300-500rpm. pH, temperature, and solid content sensors are installed in each reactor and aging vessel. The central control system dynamically adjusts the feed pump and stirrer based on the sensor data to achieve precise closed-loop control of process parameters, significantly improving product consistency.

[0030] The three measured materials (S2) are continuously and parallelly fed into a reaction system consisting of three stirred reactors connected in series through a specially designed distributor. The entire system is continuously purged with high-purity nitrogen for protection, ensuring that the oxygen content of the system is below 1 ppm.

[0031] The first reaction vessel is a nucleation vessel, and its control objective is to achieve uniform and rapid nucleation. The pH value is stably controlled at 11.5 by automatically adding alkali solution. The temperature is controlled at 55℃ by jacket constant temperature control. The stirring speed is set to 500 rpm to create a high shear force mixing environment to ensure uniform instantaneous supersaturation. At the same time, the number and particle size of crystal nuclei are monitored in real time by an online particle size analyzer to provide data support for stable nucleation.

[0032] The second and third reaction vessels are growth vessels. Their control objective is to provide a stable and gentle growth environment for the crystal nuclei, promoting particle densification. The pH value is slightly reduced to 11.2; the temperature is increased to 60℃; and the stirring speed is reduced to 400 rpm to reduce shear damage to the particles, which is conducive to orderly crystal growth. At the same time, the D50 particle size and particle size distribution are monitored in real time to ensure that they grow according to the preset trajectory. The aging kettle in S4 continuously overflows the slurry after the co-precipitation reaction in S3 into the aging kettle for aging; the slurry overflowing from the last reaction kettle enters the 100L aging kettle and is aged at 60℃ for 6 hours; after aging, the slurry is separated into solid and liquid in S5 by a belt filter.

[0033] In S5, solid-liquid separation involves sequentially separating, washing, drying, and sieving the aged slurry to obtain a high-nickel ternary precursor product. The aged slurry undergoes continuous solid-liquid separation using a belt vacuum filter. The filter cake is washed in multi-stage countercurrent washing with hot deionized water at 60-80℃ until the conductivity of the washing liquid is below 50 μS / cm to thoroughly remove residual sodium ions, sulfate ions, and ammonia. The washed wet filter cake is then instantaneously dried in a spray dryer at an inlet temperature of 200-250℃ to obtain a free-flowing powder. Finally, the dried powder is graded using a vibrating screen, and particles with a size range of 3-15 μm are selected as the final high-nickel ternary precursor product.

[0034] The mother liquor and washing liquid in S6 are sent to the wastewater treatment system to recover valuable metal salts, alkalis, and ammonia. The recovered materials can be recycled back to the upstream process, meeting the requirements of green environmental protection and cost reduction. The mother liquor and washing wastewater generated from solid-liquid separation are sent to a dedicated wastewater treatment system. First, most of the water and trace amounts of valuable metals are recovered through membrane filtration technology, and the fresh water can be directly reused for the preparation of solutions in S1. The concentrated mother liquor enters the MVR evaporator for concentration and crystallization to recover sodium sulfate byproducts, and the concentrated ammonia water can be reused for the preparation of complexing agents. This step achieves "zero wastewater discharge" and "full recovery of valuable materials", with significant environmental and economic benefits.

[0035] The system uses high-purity nickel sulfate, cobalt sulfate, and manganese sulfate as raw materials to prepare a homogeneous mixed salt solution with a target Ni:Co:Mn ratio of 83:12:5. Simultaneously, a sodium hydroxide precipitant solution and a composite complexing agent solution composed of ammonia and potassium sodium tartrate are prepared separately.

[0036] The three solutions are then independently delivered by precision metering pumps. Their flow rates are not fixed but dynamically adjusted based on real-time signal feedback from inside the reactor. The core control logic is as follows: by monitoring data from online pH meters and ammonia concentration meters within the reactor, the central control system (DCS / PLC) automatically and precisely adjusts the feed rates of the alkali solution and complexing agent to maintain a stable supersaturation level in the reaction system. This is a prerequisite for achieving uniform nucleation and controlled growth.

[0037] The mixed solution is continuously and concurrently pumped into a reaction sequence consisting of at least three reactors connected in series. The entire system operates under the protection of high-purity nitrogen to prevent oxygen interference. The first reaction vessel is the nucleation vessel: its core mission is to achieve rapid and uniform primary nucleation. By maintaining a high pH of 11.5, a temperature of 55℃, and a stirring speed of 500 rpm, a high instantaneous supersaturation and strong mixing shear force are created, promoting the instantaneous and synchronous generation of a large number of fine, uniform crystal nuclei. An online particle size analyzer monitors the nucleation process in real time.

[0038] The second and subsequent reaction vessels are growth vessels: their core mission is to provide a stable and mild growth environment for crystal nuclei. In this stage, the pH value, temperature at 60℃, and stirring speed at 400 rpm are adaptively adjusted to reduce supersaturation, allowing the crystals to grow densely and orderly epitaxially, avoiding secondary nucleation, and thus obtaining precursor particles with high sphericity, narrow particle size distribution, and high tap density.

[0039] By programmatically changing the proportion of metal ions or the concentration of complexing agent in the mixed salt solution at different reactor stages, it is possible to guide the particles to form an elemental concentration gradient or porosity gradient in the radial direction. This composition / structure engineering can effectively buffer the stress of the material during cycling, suppress the generation of microcracks, and fundamentally improve the cycling stability and safety of the final cathode material.

[0040] The slurry after the reaction overflows into the aging kettle, where it is continuously stirred at a constant temperature for several hours. This process allows the still unstable microcrystals to continue maturing, making the internal crystal structure of the particles more complete and stable, while also allowing the residual metal ions on the surface to fully react, further improving the chemical homogeneity and physical stability of the product.

[0041] Finally, the aged slurry enters the continuous solid-liquid separation unit. The filter cake undergoes multi-stage countercurrent hot water washing to thoroughly remove harmful impurities such as Na⁺ and SO₄²⁻. It is then subjected to spray drying for instantaneous drying to maintain good powder dispersibility. Finally, sieving yields the final high-nickel ternary precursor product with a particle size distribution meeting requirements (e.g., 3-15 μm). The separated mother liquor and washing wastewater: most of the pure water and trace metals are recovered through membrane separation technology; the concentrate is used to recover byproducts such as sodium sulfate through mechanical steam recompression evaporation and other technologies, and the effective components such as ammonia are reused in upstream processes. This module achieves near-zero wastewater discharge and full recovery of valuable resources, significantly reducing raw material consumption and environmental costs, demonstrating significant advantages of a circular economy.

[0042] In summary, this invention upgrades the traditional intermittent, experience-dependent co-precipitation process into a continuous, stable, and precisely programmable intelligent manufacturing system through integrated intelligent control of the entire process, including precise metering, gradient reaction, real-time feedback, structural design, and closed-loop recycling. It not only ensures high performance and consistency of the product but also maximizes the greening of the production process and economic benefits through material recycling. Example

[0043] To achieve a gradient distribution of elemental concentrations within the particles, dynamic control can be performed in S3. For example: At the start of the reaction, the proportion of nickel in the mixed salt solution was set to 80%, while cobalt and manganese were 15% and 5%, respectively.

[0044] As the reaction proceeds in a series of reactors, the flow rate of nickel salt is linearly increased under program control, while the flow rate of cobalt and manganese is correspondingly decreased.

[0045] When the reaction reaches the final stage (such as the third reaction vessel), the proportion of nickel in the mixed salt solution can be adjusted to 86%, and the proportions of cobalt and manganese can be adjusted to 10% and 4%, respectively.

[0046] In this way, the nickel content of the resulting precursor particles gradually increases from the core to the surface, while the cobalt and manganese content gradually decreases, forming a concentration gradient structure that helps improve the thermal stability and cycle performance of the final cathode material.

[0047] In summary, the continuous synthesis process for high-nickel ternary precursors for lithium batteries according to an embodiment of the present invention involves first selecting high-purity nickel sulfate, cobalt sulfate, and manganese sulfate as metal salt raw materials, and preparing a mixed salt solution with a total metal ion concentration of 2 mol / L according to the Ni:Co:Mn molar ratio of 83:12:5; then preparing a 32% sodium hydroxide solution, which is diluted with pure water to 6 mol / L as a precipitant; simultaneously preparing 25% ammonia water, diluted to 10%, and adding a mixed solution of potassium sodium tartrate with a concentration of 0.1 mol / L as a complexing agent; continuously adding the mixed salt solution, precipitant, and complexing agent solution in parallel to a reaction system consisting of three 50L reactors connected in series using a metering pump at a certain flow rate ratio; wherein each reactor is equipped with an independent stirring device, heating device, temperature sensor, pH sensor, ammonia concentration sensor, and online particle size monitor to control the first reactor. The initial conditions are: pH 11.0-12.0, temperature 50-60℃, and stirring speed 400-600 rpm; this stage mainly achieves uniform nucleation. The subsequent reactor conditions are: pH 10.5-11.5, temperature 55-65℃, and stirring speed 300-500 rpm; this stage mainly achieves crystal growth. Simultaneously, pH, temperature, and solid content sensors are installed in each reactor and aging vessel; and the central control system dynamically adjusts the feed pump and stirrer based on sensor data. Achieving precise closed-loop control of process parameters significantly improves product consistency. Its central control system dynamically fine-tunes the feed rate and jacket water temperature of each solution based on the readings of online pH meters and temperature sensors in each reactor, keeping pH fluctuations within ±0.1 and temperature fluctuations within ±1℃. Then, the slurry overflowing from the third reactor enters a 100L aging reactor and is aged at 60℃ for 6 hours. After aging, the slurry undergoes solid-liquid separation via a belt filter and is washed with deionized water until the conductivity of the filtrate is below 50μS / cm. After washing, the filter cake is dried at 110℃ for 12 hours, and then classified by a vibrating sieve to obtain Ni0.83Co0.12Mn0.05(OH)2 precursor products with a particle size D50 of 8-12 μm. The filtration mother liquor and washing water are collected and sent to a recovery system. Metal hydroxides are recovered by pH adjustment and precipitation, and ammonia is recovered by distillation. The recovered sodium hydroxide and metal salts are reused to prepare appropriate solutions. A multi-stage series reactor achieves spatial separation of crystal nucleation and growth, ensuring the product has advantages such as narrow particle size distribution, good sphericity, and high tap density. Simultaneously, a precise online monitoring and control system ensures high batch-to-batch consistency. Combined with an efficient resource recovery process, this technology significantly reduces production costs and environmental impact while improving product quality, making it highly suitable for large-scale industrial production.

[0048] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0050] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A continuous synthesis process for high-nickel ternary precursors for lithium batteries, characterized in that: Includes the following steps: S1. Raw material preparation: Prepare a soluble mixed salt solution containing nickel, cobalt, and manganese; prepare an alkaline solution as a precipitant; prepare a mixed solution containing ammonia and a green complexing agent as a complexing agent; S2. Metering and mixing: The mixed salt solution, alkaline solution and complexing agent solution are quantitatively mixed using a metering system; S3, Precipitation reactor: The mixed liquid in S2 is continuously and concurrently fed into a reaction system consisting of at least three reactors connected in series; under the protection of inert gas, the reaction conditions are controlled to carry out a co-precipitation reaction to generate a ternary precursor slurry; wherein, the first reactor mainly controls the formation of crystal nuclei, and the second and subsequent reactors mainly control the growth of crystal nuclei; S4, Aging Kettle: The slurry after co-precipitation reaction in S3 is continuously overflowed into the aging kettle for aging; S5. Solid-liquid separation: The aged slurry is subjected to continuous solid-liquid separation, washing, drying and sieving to obtain high-nickel ternary precursor products. S6. Wastewater treatment and valuable metal recovery: The mother liquor and washing liquid generated from solid-liquid separation are treated to recover the alkali and metal salts, which are then reused in the preparation of the solution in S1.

2. The continuous synthesis preparation process for high-nickel ternary precursors for lithium batteries according to claim 1, characterized in that: In step S1, high-purity nickel sulfate, cobalt sulfate, and manganese sulfate are selected as metal salt raw materials. They are accurately weighed according to the required nickel, cobalt, and manganese molar ratio and dissolved in pure water to form a mixed salt solution, controlling the total metal concentration to be 2.0 mol / L. At the same time, 32% liquid alkali is prepared and diluted with pure water to 6 mol / L as a precipitant; 25% ammonia water is prepared and diluted to 10% as a complexing agent.

3. The continuous synthesis preparation process for high-nickel ternary precursors for lithium batteries according to claim 1, characterized in that: The S2 is equipped with a metering pump for precisely controlling the feed flow rates of the mixed salt solution, precipitant, and complexing agent.

4. The continuous synthesis preparation process for high-nickel ternary precursors for lithium batteries according to claim 1, characterized in that: The inert gas in S3 is high-purity nitrogen as a protective gas, with a purity ≥99.95%.

5. The continuous synthesis preparation process for high-nickel ternary precursors for lithium batteries according to claim 1, characterized in that: The S3 uses a multi-stage series reactor, each equipped with an independent stirring device, heating device, temperature sensor, pH sensor, ammonia concentration sensor and online particle size monitor.

6. The continuous synthesis preparation process for high-nickel ternary precursors for lithium batteries according to claim 1, characterized in that: The S3 uses three or more reactors in series to achieve spatial separation of crystal nucleation and growth.

7. The continuous synthesis preparation process for high-nickel ternary precursors for lithium batteries according to claim 6, characterized in that: The multiple reactors in series in S3 are as follows: the first reactor strictly controls the supersaturation to promote uniform nucleation; the subsequent reactors provide a stable growth environment to ensure dense crystal growth and reduce structural defects.

8. The continuous synthesis preparation process for high-nickel ternary precursors for lithium batteries according to claim 1, characterized in that: In the co-precipitation reaction, S3 adjusts the molar ratio of nickel, cobalt, and manganese in the mixed salt solution or adjusts the concentration of the complexing agent in stages to form an elemental concentration gradient distribution or a porosity gradient distribution inside the resulting precursor particles.

9. The continuous synthesis preparation process for high-nickel ternary precursors for lithium batteries according to claim 8, characterized in that: The control conditions for the first reactor in S3 are: pH value 11.0-12.0, temperature 50-60℃, and stirring speed 400-600rpm; the control conditions for the subsequent reactor are: pH value 10.5-11.5, temperature 55-65℃, and stirring speed 300-500rpm.

10. The continuous synthesis preparation process for high-nickel ternary precursors for lithium batteries according to claim 1, characterized in that: In step S6, the mother liquor and washing liquid are sent to the wastewater treatment system to recover valuable metal salts, alkalis and ammonia. The recovered materials can be returned to the upstream process for recycling, which meets the requirements of green environmental protection and cost reduction.

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