A method and apparatus for synthesizing lithium battery cathode material precursors

Abstract

This invention discloses a method and equipment for synthesizing a lithium-ion battery cathode material precursor, belonging to the field of new energy materials technology. The synthesis method provided by this invention includes the following steps: S1. Mixing seed crystals, water, and a complexing agent to obtain a base solution; S2. Introducing a co-precipitation reaction of a precipitant, a complexing agent, and a transition metal salt solution concurrently into a container containing the base solution, and collecting the overflow material; stopping the process when the difference between the D50 of the solid product in the container and the target D50 of the ternary precursor is 3~8 μm; S3. Combining the contents of the container in step S2 and the overflow material to obtain a mixture; S4. Using the mixture obtained in step S3 as the base material for continuous synthesis. The ternary precursor obtained by the synthesis method provided by this invention has comparable performance to the precursor produced by the traditional continuous method, and overcomes the problems of time and material waste in the traditional continuous production method. This invention also provides equipment for implementing the above synthesis method.

Description

Technical Field

[0001] This invention relates to the field of new energy materials technology, and in particular to a method and equipment for synthesizing lithium battery cathode material precursors. Background Technology

[0002] The co-precipitation method for preparing precursors of ternary lithium-ion battery cathode materials generally falls into two categories: batch and continuous. The batch method is further divided into two scenarios: water-based start-up and seed-based start-up. In the water-based start-up, only one nucleation occurs, allowing the material to grow to the target particle size before stopping the process. During this intermediate process, only feed is introduced, and no material is discharged; the mother liquor is discharged through a thickener or hopper. In the seed-based start-up, no nucleation is required; the material grows to the target particle size before stopping the process. During this intermediate process, only feed is introduced, and the mother liquor is discharged through a thickener or hopper. The batch method offers advantages such as narrow particle size distribution, good sphericity, excellent processing performance, good thermal stability, and good safety performance. However, its disadvantages include low production efficiency, high labor intensity, poor product consistency, and low energy density. The continuous method involves simultaneous feeding and discharging during the reaction process, while continuously introducing nuclei to maintain particle size balance. The slurry continuously overflows into the aging reactor through an overflow pipe. The continuous process has advantages such as wide particle size distribution, high production efficiency, low labor intensity, good product stability, high tap density, and high energy density. However, it also has the problem of a large amount of micro powder, which leads to poor consistency of the finished product after sintering. Sometimes, when preparing a new type of continuous process product for the first time, a lot of materials and time need to be wasted in order to achieve the balance and stability of the target particle size.

[0003] In summary, there is currently no production method for lithium battery cathode material precursors that possesses the advantages of continuous production while at least overcoming some of its disadvantages. Summary of the Invention

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a method for synthesizing lithium-ion battery cathode material precursors. The performance of the resulting lithium-ion battery cathode material precursors is comparable to that of precursors produced by traditional continuous methods, and the synthesis method overcomes the problems of time and material waste in traditional continuous production.

[0005] The present invention also provides an apparatus for carrying out the above-described synthesis method.

[0006] According to an embodiment of a first aspect of the present invention, a method for synthesizing a lithium-ion battery cathode material precursor is provided, the synthesis method comprising the following steps: S1. Mix seed crystals, water, and complexing agent to obtain a base solution; S2. A co-precipitation reaction is carried out by introducing a precipitant, a complexing agent, and a transition metal salt solution into a container containing the bottom liquid, and the overflow material is collected. The process is stopped when the difference between the D50 of the solid product in the container and the target D50 of the lithium battery cathode material precursor is 3~8μm. S3. Combine the contents of the container in step S2 and the overflow material to obtain a mixture; the ratio of the overflow material to the overflow material obtained in step S2 in the mixture is ≥2 / 3; S4. Using the mixture obtained in step S3 as the base material, a continuous synthesis method is carried out.

[0007] The synthesis method according to embodiments of the present invention has at least the following beneficial effects: The synthesis method provided by this invention improves product consistency compared with the traditional intermittent method, and does not require shutdown after stable operation, resulting in high production efficiency and low labor intensity.

[0008] In traditional continuous production processes, all produced materials are treated as waste until the output meets expectations and stabilizes, and a considerable amount of time is required for parameter adjustment and optimization. Compared with traditional continuous methods, the synthesis method provided by this invention can obtain lithium battery cathode material precursors with comparable or even better performance, while significantly saving time and achieving zero material waste.

[0009] According to some embodiments of the present invention, in step S1, the seed crystal is prepared by an intermittent method. Specifically, it includes the following steps: A transition metal salt solution, a complexing agent, and a precipitating agent are introduced concurrently into the bottom liquid. The substrate solution for synthesizing the seed crystals includes water, a complexing agent, and a precipitant; the volume ratio of water to precipitant is 180~220:1; the total alkalinity of the mixture of water and complexing agent is 0.4±0.02mol / L. In this invention, the total alkalinity is the ammonia concentration; the ammonia concentration refers to the concentration of an equal amount of NH3 added to the mixed system.

[0010] In the co-current synthesis of the seed crystals, the flow rate of the transition metal salt is 25.1±1 L / h; the flow rate of the precipitant is 8.6±0.5 L / h; and the flow rate of the complexing agent is 0.81±0.1 L / h. The reaction for synthesizing the seed crystals was carried out under stirring at a speed of 400±1 rpm. In the intermittent method for synthesizing the seed crystals, after the reaction vessel is full, the liquid is concentrated and purged until the target particle size of the seed crystals is reached, and then the process is stopped.

[0011] According to some embodiments of the present invention, in step S1, the seed crystal has a particle size of 3~5 μm. For example, the added crystal can be 3 μm, 4 μm, 5 μm; or a range of values ​​consisting of any two of the above points. Here, the particle size refers to the D50 particle size.

[0012] According to some embodiments of the present invention, in step S1, the substrate solution for synthesizing the lithium-ion battery cathode material precursor includes seed crystals, water, and a complexing agent. The alkalinity of the substrate solution is 0.6 ± 0.02 mol / L; the mass of the seed crystals, in volume ratio to the seed crystal and water mixture, is 27~33 kg / m³. 3 .

[0013] According to some embodiments of the present invention, in step S2, during the parallel flow, the flow rate of the precipitant is 172±2 L / h; the flow rate of the complexing agent is 51±1 L / h; and the flow rate of the transition metal salt solution is 502±5 L / h.

[0014] According to some embodiments of the present invention, in step S2, the coprecipitation reaction is carried out under stirring at a speed of 200±1 rpm.

[0015] According to some embodiments of the present invention, the target D50 of the lithium battery cathode material precursor is 9~13μm. For example, it can be 9μm, 10μm, 11μm, 12μm, 13μm; or a range of values ​​composed of any two of the above points.

[0016] Specifically, When the target D50 of the lithium battery cathode material precursor is 9~11μm (10±1μm), the D50 particle size of the solid product in the container in step S2 should be controlled within 14~16μm; for example, it can be 14μm, 15μm, 16μm; or a range of values ​​composed of any two of the above points.

[0017] When the target D50 of the lithium-ion battery cathode material precursor is 11~13μm (12±1μm), the D50 particle size of the solid product in the container in step S2 should be controlled within 17~19μm. For example, it can be 17μm, 18μm, 19μm; or a range of values ​​composed of any two of the above points.

[0018] According to some embodiments of the present invention, in step S3, the merging is slurry merging. That is, the liquid in the overflow material and the internally dispersed solid products are uniformly merged.

[0019] According to some embodiments of the present invention, in step S3, the ratio of the overflow material in the mixture to the overflow material obtained in step S2 is ≥3 / 4; for example, all the overflow materials obtained in step S2 may be combined.

[0020] According to some embodiments of the present invention, in step S3, the particle size distribution of the solid material in the mixture is normally distributed.

[0021] According to some embodiments of the present invention, in step S4, the continuous synthesis specifically includes introducing the complexing agent, the transition metal salt solution, and the precipitant concurrently into the substrate. During the concurrent introduction process, the flow rate of the precipitant is 129±2 L / h; the flow rate of the complexing agent is 34.93±1 L / h; and the flow rate of the transition metal salt solution is 376±3 L / h. The continuous synthesis is carried out under stirring, specifically at a rotation speed of 165±1 rpm. The basicity of the continuously synthesized material is 0.55±0.02 mol / L.

[0022] According to some embodiments of the present invention, the pH of the seed crystal synthesis, the co-precipitation reaction in step S2, and the continuous synthesis in step S4 is between 10.7 and 12.3. In actual production, the particle size distribution can be controlled by adjusting the pH value; for example, if the particle size is too small, the pH can be lowered, and if the particle size is too large, the pH can be raised.

[0023] According to some embodiments of the present invention, the synthesis of the seed crystals, the co-precipitation reaction in step S2, and the continuous synthesis in step S4 are carried out under a protective atmosphere. The protective atmosphere includes at least one of nitrogen and argon. The flow rate of the protective atmosphere is 2 ± 0.5 m³ / h.

[0024] According to some embodiments of the present invention, the reactor temperature for the synthesis of the seed crystals, the co-precipitation reaction in step S2, and the continuous synthesis in step S4 is 60±1℃.

[0025] According to some embodiments of the present invention, the lithium-ion battery cathode material precursor includes at least one of a binary precursor, a ternary precursor, and a multi-component precursor. The "few" indicates the types of transition metals included. For example, The binary precursor includes at least one of nickel-cobalt hydroxide, nickel-manganese hydroxide, nickel-aluminum hydroxide, and cobalt-manganese hydroxide.

[0026] The ternary precursor includes at least one of nickel cobalt manganese hydroxide and nickel cobalt aluminum hydroxide.

[0027] The multi-element precursor includes a ternary precursor containing at least one doping element.

[0028] The difference in the synthesis methods for different types of lithium battery cathode material precursors lies in the difference in the solute in the transition metal salt solution.

[0029] For example, when the molar ratio of nickel, cobalt, and manganese in the transition metal salt solution is 8:1:1, the resulting product is a precursor of the NCM811 system; if the molar ratio of nickel, cobalt, and manganese is 83:12:5, then the molar ratio of nickel, cobalt, and manganese in the resulting ternary precursor is 83:12:5.

[0030] According to some embodiments of the present invention, the Span = (D90-D10) / D50 of the lithium-ion battery cathode material precursor obtained by the synthesis method ranges from 1.0 to 1.25. For example, it can specifically be 1.0, 1.05, 1.1, 1.15, 1.2, 1.25; or a range of values ​​composed of any two of the above points.

[0031] According to some embodiments of the present invention, lithium-ion battery cathode material precursors with the same D50 particle size are synthesized. Compared with continuous methods, the synthesis method saves 3-10 days. Specifically, In the synthesis method, the preparation of the seed crystal in step S1 takes 3 to 4 days; the total time required for steps S2 to S3 is 2 to 3 days.

[0032] In the traditional continuous method, it takes 10 to 15 days until the operation is stable.

[0033] According to some embodiments of the present invention, with 10m 3 Based on the reactor design, traditional continuous production methods waste approximately 1.5 tons of material per day before achieving stable operation. Therefore, the synthesis method provided by this invention can save 15-22.5 tons of material per 10m³ reactor. 3 The reaction vessel. In other words, the synthesis method provided by this invention does not generate waste.

[0034] According to an embodiment of a second aspect of the present invention, an apparatus for implementing the synthesis method described in the first aspect of the present invention is provided, the apparatus comprising a seed tank, a first reaction vessel, a first transfer tank, a second reaction vessel, and a second transfer tank that are sequentially connected via pipelines; The overflow port and bottom of the first reactor are both connected to the first transfer tank.

[0035] Since the device employs all the technical solutions of the synthesis method described in the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments. Furthermore, the device allows for a smoother process in the synthesis method.

[0036] According to some embodiments of the present invention, the volume of the second transfer tank is 3 to 5 times the volume of the first reactor. For example, it can be 4 times.

[0037] In actual production, it is preferred to set up only one second transfer tank, that is, all the overflow material and contents of the first reactor are mixed in the second transfer tank, which is more conducive to obtaining a uniformly mixed mixture.

[0038] According to some embodiments of the present invention, the seed crystal reactor is provided with at least four seed crystal reactor feeding ports, which are respectively used for feeding protective gas, alkaline solution (precipitant), transition metal salt solution and complexing agent.

[0039] According to some embodiments of the present invention, the seed crystal reactor is further provided with a seed crystal reactor stirrer to achieve mass transfer during the seed crystal reaction process.

[0040] Based on the same material feeding and mass transfer requirements The first reactor is provided with at least four first reactor inlets; The first reactor is equipped with a first reactor stirrer; The second reactor is provided with at least four feed inlets. The second reactor is equipped with a second reactor stirrer.

[0041] Based on the same mass transfer requirements The first transfer tank is equipped with a first transfer tank agitator; The second transfer tank is equipped with a second transfer tank agitator.

[0042] To control the flow intervals and direction of materials, valves are installed on the pipes connecting two adjacent devices.

[0043] To enable the transportation of materials from lower to higher levels; A transfer pump is installed on the pipeline connecting the bottom of the first reactor and the first transfer tank.

[0044] A transfer pump 700 is installed on the pipeline connecting the bottom of the first transfer tank and the second reactor.

[0045] In actual production, the seed crystals in step S1 are prepared in the seed crystal reactor; the co-precipitation reaction in step S2 is prepared in the first reactor; the overflow material in step S2 and the merging in step S3 are carried out in the first transfer tank; the continuous process in step S4 is carried out in the second reactor, and the resulting product is temporarily stored in the second transfer tank.

[0046] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0047] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of the device used in the embodiments of the present invention.

[0048] Figure 2 This is a particle size distribution diagram of the intermediate product obtained in step S3 of Example 1 of the present invention.

[0049] Figure 3This is a particle size distribution diagram of the first batch of ternary precursors obtained in step S4 of Embodiment 1 of the present invention.

[0050] Figure 4 This is a particle size distribution diagram of the fifth batch of ternary precursors obtained in step S4 of Embodiment 1 of the present invention.

[0051] Figure 5 This is a particle size distribution diagram of the 20th batch of ternary precursors obtained in step S4 of Embodiment 1 of the present invention.

[0052] Figure 6 This is a particle size distribution diagram of the intermediate product obtained in step S3 of embodiment 3 of the present invention.

[0053] Figure 7 This is a particle size distribution diagram of the intermediate product obtained in step S3 of Comparative Example 2 of the present invention.

[0054] Figure 8 This is a particle size distribution diagram of the intermediate product obtained in step S3 of Comparative Example 3 of the present invention.

[0055] Figure 9 This is an SEM image of the seed crystal obtained in step S1 of Embodiment 1 of the present invention.

[0056] Figure 10 This is an SEM image of the intermediate product in the first reaction vessel when D50 = 7 μm in step S2 of Example 1 of the present invention.

[0057] Figure 11 This is an SEM image of the intermediate product in the first reaction vessel when D50 = 9 μm in step S2 of Example 1 of the present invention.

[0058] Figure 12 This is an SEM image of the intermediate product in the first reaction vessel when D50 = 11 μm in step S2 of Example 1 of the present invention.

[0059] Figure 13 This is an SEM image of the intermediate product in the first reaction vessel when D50 = 14.8 μm in step S2 of Example 1 of the present invention.

[0060] Figure 14 This is an SEM image of the mixture obtained in step S3 of Example 1 of the present invention.

[0061] Figure 15 This is an SEM image of the mixture obtained in step S3 of Example 1 of the present invention.

[0062] Figure 16 This is an SEM image of the product obtained after 10 days of stable production in step S4 of Embodiment 1 of the present invention.

[0063] Figure 17 This is an SEM image of the product obtained after 10 days of stable production in step SS4 of Embodiment 1 of the present invention.

[0064] Figure 18 This is a particle size distribution diagram of the ternary precursor obtained in Comparative Example 1 of the present invention.

[0065] Figure 19 This is a particle size distribution diagram of the mixture obtained in step S2 of Comparative Example 4 of the present invention.

[0066] Figure 20 This is the XRD pattern of the fourth batch of products in Example 1 of the present invention.

[0067] Figure 21 This is the XRD pattern of the qualified particle size product obtained by the continuous method in Comparative Example 1 of this invention.

[0068] Figure label: Seed crystal reactor 100, seed crystal reactor inlet 110, seed crystal reactor agitator 120; First reactor 200, first reactor inlet 210, first reactor agitator 220; First transfer tank 300, first transfer tank agitator 310; Second reactor 400, second reactor inlet 410, second reactor agitator 420; Second transfer tank 500, second transfer tank agitator 510; Valves 600, transfer pumps 700, pipelines 800. Detailed Implementation

[0069] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0070] Example 1 This example provides a method for synthesizing a ternary precursor and an apparatus for carrying out the above synthesis method.

[0071] refer to Figure 1 The equipment used in this example consists of a seed tank 100, a first reaction vessel 200, a first transfer tank 300, a second reaction vessel 400, and a second transfer tank, which are connected in sequence via pipes 800. The overflow port and bottom of the first reaction vessel 200 are both connected to the first transfer tank 300. The seed tank 100 is provided with at least four seed tank feeding ports 110 for the feeding of protective gas, alkaline solution (precipitant), transition metal salt solution and complexing agent, respectively; in addition, the seed tank 100 is also provided with a seed tank stirrer 120 to realize mass transfer during the seed reaction process.

[0072] Based on the same feeding and mass transfer requirements, the first reactor 200 is provided with at least four first reactor inlets 210 and a first reactor agitator 220; the second reactor 400 is provided with at least four second reactor inlets 410 and a second reactor agitator 420.

[0073] Based on the same mass transfer requirements, the first transfer tank 300 is equipped with a first transfer tank agitator 310; the second transfer tank 500 is equipped with a second transfer tank agitator 510.

[0074] To control the flow interval and flow direction of materials, a valve 600 is installed on the pipe 800 connecting two adjacent devices; to realize the transportation of materials from low level to high level, a transfer pump 700 is installed on the pipe 800 connecting the bottom of the first reactor 200 and the first transfer tank 300, and on the pipe 800 connecting the bottom of the first transfer tank 300 and the second reactor.

[0075] In this example, the volume of the seed crystal reactor is 1m³. 3 The volumes of the first and second reaction vessels are 10m³. 3 The first transfer tank has a volume of 50m³. 3 The volume of the second transfer tank is 20m³. 3 .

[0076] In this example, the target particle size for synthesizing the ternary precursor is 10 ± 0.5 μm; the specific steps are as follows: S1. S1a. Seed Crystal Synthesis: Seed crystals with a D50 of 3.4 ± 0.1 μm were prepared in the seed reactor using an intermittent method. Specifically, The preparation of the base solution for synthesizing seed crystals is as follows: Add 200±20L of pure water to a 1m³ seed crystal reactor and start stirring at 400±1rpm; circulate ammonia water to adjust the total alkalinity to 0.40±0.02mol / L; add 1L of base alkali (32% sodium hydroxide solution); raise the reactor temperature to 60±1℃; The concentration of the transition metal salt solution for synthesizing seed crystals was 1.70±0.02 mol / L, wherein the transition metal salts were nickel sulfate, cobalt sulfate and manganese sulfate in a molar ratio of 83:12:5; the precipitant was a sodium hydroxide solution of 10.5±0.5 mol / L; and the complexing agent was an ammonia solution of 8.5±0.5 mol / L. Nitrogen gas, acting as a protective gas, is introduced into the seed reactor containing the bottom crystal at a flow rate of 2±0.5 m³ / h; the reactor is then sealed; a transition metal salt solution, a complexing agent, and a precipitant are introduced into the reactor in parallel; the flow rates of the transition metal salt solution are 25.1±1 L / h, the precipitant is 8.6±0.5 L / h, and the complexing agent is 0.81±0.1 L / h; the pH is maintained at 11.5±0.5 during the reaction; once the liquid level in the seed reactor is full, the concentrate is turned on to remove the precipitant; the reactor is stopped when the D50 reaches 3.4-3.6 μm.

[0077] S1b. Preparation of the base solution: The base solution consists of the following components: 270±10kg seed crystals (dry weight), pure water and ammonia water, wherein the volume of seed crystals and pure water is 9±0.5m³; the complexing agent ammonia water is used to adjust the total alkalinity to 0.6±0.02mol / L.

[0078] S2. Raise the temperature of the first reactor to 60±1℃, start stirring at 200±1 rpm, and introduce protective nitrogen gas at a flow rate of 2.0±0.5 m³ / h. Then, simultaneously introduce a precipitant, a complexing agent, and a transition metal salt solution (with the same concentration, composition, and seed crystal synthesis process) into the first reactor to begin co-precipitation. The flow rate of the precipitant is 172±2 L / h, the flow rate of the complexing agent is 51±1 L / h, and the flow rate of the transition metal salt solution is 502±5 L / h. During the reaction, control the pH at 11.5±0.5.

[0079] Once the liquid level in the first reactor is full, open the overflow valve to allow the material to overflow into the first transfer tank, where the overflowing material will be collected.

[0080] Stop the reactor when the material D50 in the first reactor reaches 14.5~15μm.

[0081] S3. The material in the first reactor is discharged through the bottom of the reactor and mixed with the material that previously overflowed into the first transfer tank. At this point, the particle size distribution of the material is close to the particle size distribution during stable continuous production.

[0082] S4. Transfer 9.5 m³ of the mixed material obtained in step S3 into the second reactor. Open the second reactor and feed and discharge normally. The produced material is the qualified ternary precursor material. During the reaction in this step, the reactor temperature is 60±1℃, the stirring speed is 165±1 rpm, the total alkalinity is 0.55±0.02 mol / L, and the flow rate of the protective gas nitrogen is 2±0.5 m³ / h. The concentrations and compositions of the precipitant, complexing agent, and transition metal salt solution in the feed are the same as those used in the seed crystal synthesis process. The specific flow rates are 129±2 L / h for the precipitant, 34.93±1 L / h for the complexing agent, and 376±3 L / h for the transition metal salt solution. The pH is controlled at 11.5±0.8.

[0083] In this example, "±" and the range of values ​​within the interval both represent the allowable range of changes in actual production. Changing the parameters within the corresponding interval will not lead to significant changes in the product performance.

[0084] Example 2 This example provides a method for synthesizing a ternary precursor and an apparatus for carrying out the above synthesis method. The specific difference from Example 1 is as follows: (1) In the equipment, the volume of the first transfer tank is 30m³. 3 ; (2) The target D50 particle size of the ternary precursor in this example is 12 ± 0.5 μm. Correspondingly, In step S1a, the machine is stopped when the seed crystal D50 reaches 4.0μm±0.1μm.

[0085] In step S2, the reactor is stopped when the material D50 in the first reactor reaches 17-17.5μm.

[0086] Example 3 This example prepares a ternary precursor, which differs from Example 1 in that: In step S3, only 2 / 3 of the overflow material was mixed and used.

[0087] Comparative Example 1 This example demonstrates the continuous production of ternary precursors, with the specific steps as follows: D1. Add to the reactor (10m³ volume) 3 Add 2±0.1 m³ of pure water, 10±0.1 L of 32% sodium hydroxide precipitant, and 129±10 L of 14.5% ammonia solution as a complexing agent to the solution. D2. Raise the reactor temperature to 60±1℃, start stirring at 165±1 rpm, and purge with nitrogen at a rate of 2.0±0.5 m³ / h for protection. Then, simultaneously introduce the same precipitant, complexing agent, and metal salt solution as in step D1 into the reactor. The precipitant flow rate is 129±2 L / h, the complexing agent flow rate is 34.93±1 L / h, and the metal salt solution is a mixed solution of nickel-cobalt-manganese sulfate (molar ratio Ni:Co:Mn=82:12:5) with a total concentration of 100 g / L (1.70±0.02 mol / L) and a flow rate of 376±3 L / h. Control the pH to 11.5±0.8 to initiate co-precipitation. When the reactor is full, open the overflow valve to simultaneously feed and discharge the materials.

[0088] During the process, when the particle size D50 is too small, the pH is lowered to 10.8-11.5 to promote rapid growth of the material. When the D50 is too large, the pH is raised to 11.5-12.3 to induce secondary nucleation and reduce the average particle size. By controlling the pH, the particle size distribution is regulated to meet the requirements, and a ternary precursor with D50 of 10±1μm is obtained.

[0089] Comparative Example 2 This example prepares a ternary precursor, which differs from Example 1 in that: In step S3, only 1 / 2 of the overflow material was mixed and used.

[0090] Comparative Example 3 This example prepares a ternary precursor, which differs from Example 1 in that: In step S3, only 1 / 3 of the overflow material was mixed and used.

[0091] Comparative Example 4 This example provides a method for synthesizing a ternary precursor and an apparatus for carrying out the above synthesis method; the specific difference from Example 1 is as follows: (1) The volume of the first transfer tank is 30m³. 3 .

[0092] (2) In step S2, stop the machine when the material D50 in the first reactor reaches 19-19.5μm.

[0093] Test case The first aspect of this example summarizes the time taken from startup to stabilization and the materials wasted in Example 1 and Comparative Example 1, as shown in Table 1.

[0094] Table 1. Time required and material wastage statistics for Example 1 and Comparative Example 1. Example 1 Comparative Example 1 time consuming 6 days 13 days Waste quantity (dry weight) 0 19.5t In Table 1, the time taken for Example 1 includes the preparation of the seed crystal in step S1 and other steps. The seed crystal preparation took 3 days, and steps S2 to S3 took 3 days.

[0095] The second aspect of this example tested the particle size distribution of the products obtained in the embodiments and comparative examples using a laser particle size analyzer. The test results are shown in Table 2. Figures 2-8 as well as Figures 18-19 As shown.

[0096] Table 2. Particle size distribution of intermediate products (mixture obtained in step S3) and final products (ternary precursor obtained in step S4) of the examples and comparative examples.

[0097] In Table 1, each batch consists of 4 tons of dried ternary precursor produced.

[0098] As shown in Table 2, the particle size distribution of the mixtures obtained in step S3 of Examples 1 and 3 is basically the same as that of the ternary precursor obtained in Comparative Example 1, and the performance of multiple batches of products in Example 1 is consistent. It can also be seen that, compared with Example 3, the particle size distribution of the mixture obtained in step S3 of Example 1 is closer to a normal distribution.

[0099] The third aspect of this example tested the SEM images of the seed crystals in Example 1, the products obtained when D50 reached different levels in the first reactor in step S2, and the products after 10 days of stable production in steps S3 and S4, as detailed below. Figures 9-17 As shown. The results indicate that the mixture obtained in step S3 is visually similar to the product after 10 days of stable production.

[0100] The fourth aspect of this example tested the XRD results of the fourth batch of product from Example 1 and the product after stable production in Comparative Example 1. The results showed that the ternary precursor prepared by the synthesis method of this invention has almost identical properties to the precursor prepared by the conventional continuous method. Specific results are as follows: Figures 20-21 As shown in Table 3.

[0101] Table 3 Comparison of XRD data of ternary precursors obtained in Comparative Example 1 and Example 1 name 001 Peak position (°) Half-peak width of peak 001 (°) 001 Peak Strength (au) Half-peak width of peak 101 (°) 101 peak strength (au) 101 / 001 Comparative Example 1 19.274 0.512 2178 0.524 2596 1.192 Example 1, Batch 4 19.238 0.507 2197 0.506 2470 1.124 In summary, the present invention provides a method for synthesizing lithium battery cathode material precursors and an apparatus for implementing the above synthesis method. The combination of the two can obtain lithium battery cathode material precursors with performance consistent with traditional continuous methods, while reducing material waste and saving preparation time.

[0102] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A method for synthesizing a lithium-ion battery cathode material precursor, characterized in that, The synthesis method includes the following steps: S1. Mix seed crystals, water, and complexing agent to obtain a base solution; S2. A co-precipitation reaction is carried out by introducing a precipitant, a complexing agent, and a transition metal salt solution into a container containing the bottom liquid, and the overflow material is collected. The process is stopped when the difference between the D50 of the solid product in the container and the target D50 of the lithium battery cathode material precursor is 3~8μm. S3. Combine the contents of the container in step S2 and the overflow material to obtain a mixture; the ratio of the overflow material to the overflow material obtained in step S2 in the mixture is ≥2 / 3; S4. Using the mixture obtained in step S3 as the base material, a continuous synthesis method is carried out.

2. The synthesis method according to claim 1, characterized in that, In step S1, the seed crystal has a particle size of 3~5μm.

3. The synthesis method according to claim 1, characterized in that, In step S1, the seed crystal is prepared by an intermittent method.

4. The synthesis method according to claim 1, characterized in that, The target D50 of the lithium battery cathode material precursor is 9~13μm.

5. The synthesis method according to any one of claims 1 to 4, characterized in that, The synthesis method for lithium-ion battery cathode material precursors with the same D50 particle size saves 3 to 10 days compared to the continuous method.

6. The synthesis method according to any one of claims 1 to 4, characterized in that, The Span = (D90-D10) / D50 of the lithium-ion battery cathode material precursor obtained by the synthesis method ranges from 1.0 to 1.

25.

7. The synthesis method according to any one of claims 1 to 5, characterized in that, The pH of the seed crystal synthesis, the co-precipitation reaction in step S2, and the continuous synthesis in step S4 is between 10.7 and 12.

3.

8. The synthesis method according to any one of claims 1 to 4, characterized in that, The lithium-ion battery cathode material precursor includes at least one of binary precursors, ternary precursors, and multi-component precursors.

9. An apparatus for implementing the synthesis method according to any one of claims 1 to 8, characterized in that, The equipment includes a seed tank, a first reaction vessel, a first transfer tank, a second reaction vessel, and a second transfer tank, which are connected in sequence via pipelines. The overflow port and bottom of the first reactor are both connected to the first transfer tank.

10. The device according to claim 9, characterized in that, The volume of the first transfer tank is 3 to 5 times the volume of the first reactor.

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