Large-particle high-aluminum-doped spherical hydroxyl cobalt oxide and cobaltosic oxide and preparation method thereof
By optimizing the co-precipitation process parameters, large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide was prepared, solving the problems of wide particle size distribution and uneven morphology, and improving the performance of lithium cobalt oxide cathode.
Patent Information
- Application Number
- CN202511868200.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-11
- Publication Date
- 2026-01-23
AI Technical Summary
In existing technologies, large-particle cobalt hydroxyl oxide products have a wide particle size distribution and uneven morphology, which affects subsequent washing and filtration processes and leads to inconsistent performance.
By optimizing the co-precipitation process parameters, such as controlling the flow rate, pH value, temperature, and doping control of the cobalt-aluminum mixed solution and the precipitant solution, uniform distribution of aluminum can be achieved, and large-particle, highly aluminum-doped spherical cobalt hydroxyoxide can be prepared, which is then calcined into cobalt tetroxide.
The method of obtaining cobalt hydroxyl oxide with high tap density, narrow particle size distribution and good sphericity significantly improves the specific capacity, cycle stability and high temperature performance of lithium cobalt oxide cathode, and solves the problem of uneven doping in traditional carbonate systems.
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Figure CN121377129A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of new energy lithium battery technology, and in particular to a large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide, cobalt tetroxide, and their preparation methods. Background Technology
[0002] As lithium-ion batteries develop towards higher energy densities, the demand for lithium cobalt oxide (LiCoO2) as a cathode material continues to grow, and its performance is highly dependent on the quality of the precursor cobalt tetroxide (Co3O4). Currently, the mainstream cobalt tetroxide synthesis process on the market uses a carbonate system, prepared by calcining cobalt carbonate. Although this process is mature and widely used, it has inherent defects: during the doping modification process, due to the poor flowability and easy cracking of cobalt carbonate particles, the distribution of doping elements (such as aluminum, magnesium, etc.) is uneven, and elemental segregation easily occurs, which in turn affects the structural stability and electrochemical performance of the final lithium cobalt oxide material.
[0003] To address the shortcomings of carbonate systems, hydroxyl systems (using cobalt hydroxide as an intermediate) have been proposed as an alternative. Hydroxyl systems can achieve atomic-scale doping during the wet co-precipitation stage, allowing the target metal element to bind more uniformly with cobalt and effectively avoiding uneven element distribution. However, in the later stages of crystal growth, a large number of fine crystals are often explosively generated. This not only severely hinders the further growth of the main particles but also results in the final product being a mixture of a small amount of coarse particles and a large amount of fine powder, causing a wide particle size distribution and uneven morphology. This, in turn, creates difficulties for subsequent washing and filtration processes and seriously affects the consistency of the final product's performance.
[0004] Therefore, there is an urgent need to provide a new type of large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide to solve the technical problems of wide particle size distribution and uneven morphology of existing large-particle cobalt hydroxyl oxide products. Summary of the Invention
[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide, cobalt tetroxide, and their preparation method, thereby solving the technical problems of wide particle size distribution and uneven morphology of large-particle cobalt hydroxyl oxide products in the prior art.
[0006] In a first aspect, the present invention provides a method for preparing large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide, comprising the following steps: S1. Prepare a cobalt-aluminum mixed solution, a precipitant solution, a complexing agent solution, and a reaction substrate containing seed crystals; S2. Co-precipitation reaction is carried out by adding a cobalt-aluminum mixed solution, a precipitant solution, and a complexing agent solution in parallel streams to the reaction substrate containing seed crystals. S3. After reaching the specified particle size, solid-liquid separation and drying are performed to obtain large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide; among which, During the coprecipitation reaction, the oxidant is air, the flow rate of the cobalt-aluminum mixed solution is 280-320 L / h, the flow rate of the precipitant solution is 90-160 L / h, and the flow rate of the complexing agent solution is 0.5-1.2 L / h. The specified particle size is D50≥5μm.
[0007] In a second aspect, the present invention provides a large-particle, highly aluminum-doped spherical cobalt hydroxyoxide, which is obtained by the preparation method of the large-particle, highly aluminum-doped spherical cobalt hydroxyoxide provided in the first aspect of the present invention.
[0008] Thirdly, the present invention provides a cobalt tetroxide, which is obtained by calcining large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide provided in the second aspect of the present invention.
[0009] Compared with the prior art, the beneficial effects of the present invention include: This invention achieves uniform distribution of aluminum by optimizing co-precipitation process parameters (such as flow rate, pH value, temperature and doping control of cobalt-aluminum mixed solution and precipitant solution), while ensuring that the product has high tap density, narrow particle size distribution and good sphericity. When the resulting material is applied to high-voltage lithium cobalt oxide cathode, it can significantly improve its specific capacity, cycle stability and high-temperature performance, solving the core pain point of uneven doping in traditional carbonate systems. Attached Figure Description
[0010] Figure 1 This is a process flow diagram of one embodiment of the preparation method of large-particle, highly aluminum-doped spherical cobalt hydroxyoxide provided by the present invention; Figure 2 This is a SEM image of cobalt hydroxyoxide (D50=5.0μm) synthesized in Example 1 of this invention; Figure 3 This is a SEM image of cobalt hydroxyoxide (D50=10.0μm) synthesized in Example 2 of this invention; Figure 4 This is a SEM image of cobalt hydroxyoxide (D50=12.0μm) synthesized in Example 3 of this invention. Detailed Implementation
[0011] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0012] Please see Figure 1 In a first aspect, the present invention provides a method for preparing large-particle, highly aluminum-doped spherical cobalt hydroxyoxide, comprising the following steps: S1. Prepare a cobalt-aluminum mixed solution, a precipitant solution, a complexing agent solution, and a reaction substrate containing seed crystals; S2. Co-precipitation reaction is carried out by adding a cobalt-aluminum mixed solution, a precipitant solution, and a complexing agent solution in parallel streams to the reaction substrate containing seed crystals. S3. After reaching the specified particle size, solid-liquid separation and drying are performed to obtain large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide; among which, During the coprecipitation reaction, the oxidant is air, the flow rate of the cobalt-aluminum mixed solution is 280-320 L / h, including but not limited to 280 L / h, 290 L / h, 300 L / h, 310 L / h, 320 L / h, etc., the flow rate of the precipitant solution is 90-160 L / h, including but not limited to 90 L / h, 110 L / h, 130 L / h, 150 L / h, 160 L / h, etc., and the flow rate of the complexing agent solution is 0.5-1.2 L / h, including but not limited to 0.5 L / h, 0.7 L / h, 0.9 L / h, 1.1 L / h, 1.2 L / h, etc.; The specified particle size is D50≥5μm.
[0013] In this embodiment, the concentration of cobalt ions in the cobalt-aluminum mixed solution is 110-130 g / L and the concentration of aluminum ions is 1.6-1.8 g / L.
[0014] This invention does not limit the types of cobalt and aluminum sources in the cobalt-aluminum mixed solution; those skilled in the art can select them according to the actual situation. In some specific embodiments of this invention, the cobalt source includes cobalt chloride hexahydrate and / or cobalt sulfate, and the aluminum source includes anhydrous aluminum chloride and / or aluminum sulfate.
[0015] In this embodiment, the precipitant solution is a sodium hydroxide solution with a mass fraction of 30%-40% (more specifically 35%).
[0016] In this embodiment, the concentration of the complexing agent in the complexing agent solution is 0.1-0.5 g / L.
[0017] In this embodiment, the complexing agent is at least one of sodium citrate, EDTA, and sodium pyrophosphate.
[0018] In this embodiment, the pH of the reaction substrate containing the seed crystals is 10.1-10.7.
[0019] In this embodiment, the reaction substrate containing the seed crystals is a sodium hydroxide solution containing the seed crystals with a pH of 10.1-10.7.
[0020] In this embodiment, the seed crystal is cobalt tetroxide seed crystal, which is a near-spherical particle with a particle size D50 of 3-4 μm and a BET specific surface area of 3-5 m². 2 / g, tap density TD is 2.0-2.2g / cm³. 3 The cobalt tetroxide seed crystals selected in this invention have a near-spherical morphology, which is beneficial for providing an isotropic growth starting point with the lowest surface energy, thereby promoting uniform and stable crystal growth and reducing defects. By controlling the particle size of the cobalt tetroxide seed crystals within the above-mentioned range, this invention can ensure the stable existence of the seed crystals and provide sufficient growth sites, while also efficiently and uniformly inducing the controllable growth of the target crystal. By controlling the BET specific surface area within the above-mentioned range, this invention can ensure that it maintains its own stability while providing sufficient active growth sites, thereby achieving efficient and controllable crystal-induced growth. By controlling the tap density TD within the above-mentioned range, this invention can ensure the acquisition of highly aluminum-doped spherical cobalt hydroxyl oxide with a high tap density, while avoiding the problem of rapid sedimentation and uneven distribution in solution due to excessively high tap density TD, and the reduction of effective growth surface area due to agglomeration, which would lead to uneven crystal growth and deterioration of particle size distribution.
[0021] In this embodiment, the seed crystal content in the reaction substrate is 60-70 g / L. If the seed crystal content is too low, new crystal nuclei will be formed, resulting in mixed phases; if the seed crystal content is too high, the growth rate will be slow.
[0022] In this embodiment, air and a cobalt-aluminum mixed solution are injected together into the reaction substrate containing seed crystals.
[0023] In this embodiment, the airflow rate is 18-22 m³ / h. 3 / h.
[0024] In this embodiment, during the coprecipitation reaction, the pH value of the reaction system is controlled to be 10.1-10.7, including but not limited to 10.1, 10.3, 10.5, 10.7, etc., the reaction temperature is 65℃-78℃, and the rotation speed is 200-250r / min.
[0025] In this embodiment, the specified particle size is a particle size D50 of 5-15μm, including but not limited to 5μm, 10μm, 12μm, 15μm, etc.
[0026] In this embodiment, solid-liquid separation includes filtration and washing.
[0027] In some specific embodiments of the present invention, the washing is performed until the chloride ion concentration in the washing liquid is below 20 ppm.
[0028] In this embodiment, the drying process includes: Nitrogen gas was purged until the moisture content was below 1% (further to 0.5%-1.0%), and then dried to obtain large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide.
[0029] The drying temperature is 150-200℃, and the drying time is 2-4 hours.
[0030] In a second aspect, the present invention provides a large-particle, highly aluminum-doped spherical cobalt hydroxyoxide, which is obtained by the preparation method of the large-particle, highly aluminum-doped spherical cobalt hydroxyoxide provided in the first aspect of the present invention.
[0031] In this embodiment, the particle size D50 of the large, highly aluminum-doped spherical cobalt hydroxyl oxide is ≥ 5 μm, further 5-15 μm, including but not limited to 5 μm, 10 μm, 12 μm, 15 μm, etc.; the specific surface area is 2.5-4.5 m². 2 / g, tap density is 2-3g / cm³ 3 Further, it is 2-2.5 g / cm³. 3 The Al content is ≥0.7%, including but not limited to 0.7%, 0.9%, 1.1%, 1.3%, 1.5%, etc.
[0032] Thirdly, the present invention provides a cobalt tetroxide, which is obtained by calcining large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide provided in the second aspect of the present invention.
[0033] In this embodiment, the calcination temperature is 600-700℃ and the calcination time is 4-6 hours.
[0034] Example 1 (1) Solution preparation Cobalt chloride hexahydrate and anhydrous aluminum chloride were mixed with water to prepare a cobalt-aluminum mixed solution with a cobalt ion concentration of 120 g / L and an aluminum concentration of 1.7 g / L; sodium citrate was mixed with water to prepare a complexing agent solution with a concentration of 0.3 g / L; and sodium hydroxide was mixed with water to prepare a precipitant solution with a mass fraction of 35%.
[0035] (2) Wet synthesis Cobalt tetroxide seed crystals (particle size D50 of 3.3 μm and BET specific surface area of 4.2 m²) were added to the reactor. 2 / g, tap density TD is 2.08g / cm³ 3 Add pure water until the liquid level reaches the overflow port, then add a 32% sodium hydroxide solution to adjust the pH to 10.70 as the reaction base solution. The content of cobalt tetroxide seed crystals in the reaction base solution is 60 g / L. Control the stirring speed at 220 r / min. Add the cobalt-aluminum mixed solution, precipitant solution, and complexing agent solution to the reactor in a parallel flow continuously. The flow rate of the cobalt-aluminum mixed solution is 320 L / h, the flow rate of the precipitant solution is 160 L / h, and the flow rate of the complexing agent solution is 1.2 L / h. The oxidant is air, which is injected into the reactor along with the cobalt-aluminum mixed solution through an injector at a flow rate of 22 m³ / h. 3 / h, control the pH of the reaction system to 10.5-10.7, and the reaction temperature to 70℃; starting from the overflow, the overflow material is transferred to the finished product tank; this process does not require a thickener, and the reactant material is simultaneously fed into and out of the finished product tank.
[0036] (3) Washing and drying The material in the finished product tank is circulated and demagnetized until the magnetic content is qualified. Then it is transferred to a filter press for filtration and washing until the chloride ion concentration in the washing liquid is lower than 20ppm. Then it is purged with nitrogen to obtain a semi-dry material with a water content of 0.8%. The semi-dry material is placed into saggers, 25kg per sagger, and dried in a pusher kiln at 180℃ for 3 hours to obtain the finished cobalt hydroxyl oxide.
[0037] (4) Calcination Cobalt hydroxyl oxide is calcined in a calcining furnace at 650°C for 5 hours to obtain cobalt tetroxide.
[0038] Example 2 (1) Solution preparation Cobalt chloride hexahydrate and anhydrous aluminum chloride were mixed with water to prepare a cobalt-aluminum mixed solution with a cobalt ion concentration of 110 g / L and an aluminum concentration of 1.6 g / L; EDTA was mixed with water to prepare a complexing agent solution with a concentration of 0.1 g / L; and sodium hydroxide was mixed with water to prepare a precipitant solution with a mass fraction of 35%.
[0039] (2) Wet synthesis Cobalt tetroxide seed crystals (particle size D50 of 3.5 μm and BET specific surface area of 3.7 m²) were added to the reactor. 2 / g, tap density TD is 2.11g / cm³ 3 Add pure water until the liquid level reaches the overflow port, then add a 32% sodium hydroxide solution to adjust the pH to 10.70 as the reaction base solution. The content of cobalt tetroxide seed crystals in the reaction base solution is 65 g / L. Control the stirring speed at 200 r / min, and continuously add the cobalt-aluminum mixed solution, precipitant solution, and complexing agent solution to the reactor in a co-current flow. The flow rate of the cobalt-aluminum mixed solution is 300 L / h, the flow rate of the precipitant solution is 120 L / h, and the flow rate of the complexing agent solution is 0.8 L / h. The oxidant is air, which is injected into the reactor along with the cobalt-aluminum mixed solution through an injector at a flow rate of 20 m³ / h. 3 / h, control the pH of the reaction system to 10.3-10.5, and the reaction temperature to 65℃; starting from the overflow, the overflow material is transferred to the finished product tank; this process does not require a thickener, and the reactant material is simultaneously fed into and out of the finished product tank.
[0040] (3) Washing and drying The material in the finished product tank is circulated and demagnetized until the magnetic content is qualified. Then it is transferred to a filter press for filtration and washing until the chloride ion concentration in the washing liquid is lower than 20ppm. Then it is purged with nitrogen to obtain a semi-dry material with a water content of 1.0%. The semi-dry material is placed into saggers, 50kg per sagger, and dried in a pusher kiln at 150℃ for 4 hours to obtain the finished cobalt hydroxyl oxide.
[0041] (4) Calcination Cobalt hydroxyoxide is calcined in a calcining furnace at 600°C for 4 hours to obtain cobalt tetroxide.
[0042] Example 3 (1) Solution preparation Cobalt chloride hexahydrate and anhydrous aluminum chloride were mixed with water to prepare a cobalt-aluminum mixed solution with a cobalt ion concentration of 130 g / L and an aluminum concentration of 1.8 g / L; sodium pyrophosphate was mixed with water to prepare a complexing agent solution with a concentration of 0.5 g / L; and sodium hydroxide was mixed with water to prepare a precipitant solution with a mass fraction of 35%.
[0043] (2) Wet synthesis Cobalt tetroxide seed crystals (particle size D50 of 3.9 μm and BET specific surface area of 3.4 m²) were added to the reactor. 2 / g, tap density TD is 2.17g / cm³ 3 Add pure water until the liquid level reaches the overflow port, then add a 32% sodium hydroxide solution to adjust the pH to 10.70 as the reaction base solution. The content of cobalt tetroxide seed crystals in the reaction base solution is 70 g / L. Control the stirring speed at 250 r / min, and continuously add the cobalt-aluminum mixed solution, precipitant solution, and complexing agent solution to the reactor in a co-current manner. The flow rate of the cobalt-aluminum mixed solution is 280 L / h, the flow rate of the precipitant solution is 90 L / h, and the flow rate of the complexing agent solution is 0.5 L / h. The oxidant is air, which is injected into the reactor along with the cobalt-aluminum mixed solution through an injector at a flow rate of 18 m³ / h. 3 / h, control the pH of the reaction system to 10.1-10.3 and the reaction temperature to 78℃; starting from the overflow, the overflow material is transferred to the finished product tank; this process does not require a thickener, and the reactant material is simultaneously fed into and out of the finished product tank.
[0044] (3) Washing and drying The material in the finished product tank is circulated and demagnetized until the magnetic content is qualified. Then it is transferred to a filter press for filtration and washing until the chloride ion concentration in the washing liquid is lower than 20ppm. Then it is purged with nitrogen to obtain a semi-dry material with a water content of 0.5%. The semi-dry material is placed into saggers, 30kg per sagger, and dried in a pusher kiln at 200℃ for 2 hours to obtain the finished cobalt hydroxyl oxide.
[0045] (4) Calcination Cobalt hydroxyl oxide is calcined in a calcining furnace at 700°C for 6 hours to obtain cobalt tetroxide.
[0046] Comparative Example 1 Compared with Example 3, the only difference is that the content of cobalt tetroxide seed crystals in the reaction substrate is 50 g / L.
[0047] Comparative Example 2 Compared with Example 3, the only difference is that the content of cobalt tetroxide seed crystals in the reaction substrate is 80 g / L.
[0048] Comparative Example 3 Compared to Example 3, the only difference is that the cobalt tetroxide seed crystals have a particle size D50 of 2.7 μm and a BET specific surface area of 4.5 m². 2 / g, tap density is 1.87g / cm³ 3 .
[0049] Comparative Example 4 Compared to Example 3, the only difference is that the cobalt tetroxide seed crystals have a particle size D50 of 4.5 μm and a BET specific surface area of 2.8 m². 2 / g, tap density is 2.31g / cm³ 3 .
[0050] Comparative Example 5 Compared with Example 3, the only difference is that the flow rate of the cobalt-aluminum mixed solution is 90 L / h, and the flow rate of the precipitant solution is 280 L / h.
[0051] Physicochemical index testing The performance of cobalt hydroxyoxide prepared in the above examples and comparative examples was tested, and the test results are shown in Table 1.
[0052] Table 1 Physical properties of cobalt hydroxyoxide
[0053] Please refer to Table 1 and Figure 2-4 Through Table 1 and Figure 2-4It can be seen that the cobalt hydroxyl oxide prepared in Examples 1-3 of this invention all have high tap density, narrow particle size distribution, good sphericity, and low sodium content (generally, the sodium content of hydroxyl systems is 750-1000 ppm). Examples 3 and Comparative Examples 1-5 show that, at the same particle size level, the amount of seed crystals added, the seed crystal size, specific surface area, tap density, and the flow rates of the cobalt-aluminum mixed solution and the precipitant solution all affect the physical properties of cobalt hydroxyl oxide, such as tap density and particle size distribution. Only by controlling the above parameters within the range specified in this application can cobalt hydroxyl oxide with large particle size, high tap density, narrow particle size distribution, and good sphericity be obtained.
[0054] Compared with the prior art, the beneficial effects of the present invention also include: (1) This invention achieves uniform distribution of aluminum by optimizing co-precipitation process parameters (such as flow rate, pH value, temperature and doping control of cobalt-aluminum mixed solution and precipitant solution), while ensuring that the product has high tap density, narrow particle size distribution and good sphericity. When the resulting material is applied to high-voltage lithium cobalt oxide cathode, it can significantly improve its specific capacity, cycle stability and high-temperature performance, solving the core pain point of uneven doping in traditional carbonate systems.
[0055] (2) By adopting the continuous overflow method, the particle size of cobalt hydroxyoxide is controlled by controlling the co-precipitation process parameters (such as the flow rate of the cobalt-aluminum mixed solution and the precipitant solution, pH value, etc.), so as to realize the simultaneous feeding and output of finished product. This reduces the losses caused by the shutdown of the reactor due to sudden situations during the production process. The continuous overflow method is producing finished product at all times, ensuring that the subsequent filter press and calcining furnace are always in a state of material supply. The efficient continuous operation effectively reduces the production cost. Moreover, the cobalt hydroxyoxide synthesized by this invention has high sphericity and uniform particle size.
[0056] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. A method for preparing large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide, characterized in that, Includes the following steps: Prepare a cobalt-aluminum mixed solution, a precipitant solution, a complexing agent solution, and a reaction substrate containing seed crystals; The cobalt-aluminum mixed solution, the precipitant solution, and the complexing agent solution are added concurrently to the reaction substrate containing the seed crystals to carry out a coprecipitation reaction; After reaching the specified particle size, solid-liquid separation and drying are performed to obtain large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide; among which, During the coprecipitation reaction, the oxidant is air, the flow rate of the cobalt-aluminum mixed solution is 280-320 L / h, the flow rate of the precipitant solution is 90-160 L / h, and the flow rate of the complexing agent solution is 0.5-1.2 L / h. The specified particle size is a particle size D50 ≥ 5 μm.
2. The method for preparing large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide according to claim 1, characterized in that, In the cobalt-aluminum mixed solution, the concentration of cobalt ions is 110-130 g / L and the concentration of aluminum ions is 1.6-1.8 g / L; and / or, The precipitant solution is a 30%-40% sodium hydroxide solution by mass; and / or, The concentration of the complexing agent in the complexing agent solution is 0.1-0.5 g / L; and / or, The pH of the reaction substrate containing the seed crystals is 10.1-10.
7.
3. The method for preparing large-particle, highly aluminum-doped spherical cobalt hydroxyoxide according to claim 1, characterized in that, The complexing agent is at least one of sodium citrate, EDTA, and sodium pyrophosphate; and / or, The reaction substrate containing the seed crystals is a sodium hydroxide solution containing the seed crystals with a pH of 10.1-10.
7.
4. The method for preparing large-particle, highly aluminum-doped spherical cobalt hydroxyoxide according to claim 1, characterized in that, The seed crystal is cobalt tetroxide seed crystal, which is a near-spherical particle with a particle size D50 of 3-4 μm and a BET specific surface area of 3-5 m². 2 / g, tap density TD is 2.0-2.2g / cm³. 3 .
5. The method for preparing large-particle, highly aluminum-doped spherical cobalt hydroxyoxide according to claim 1, characterized in that, The content of the seed crystals in the reaction substrate is 60-70 g / L.
6. The method for preparing large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide according to claim 1, characterized in that, The air and the cobalt-aluminum mixed solution are injected together into the reaction substrate containing the seed crystals; and or, The air flow rate is 18-22 m³ / h. 3 / h.
7. The method for preparing large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide according to claim 1, characterized in that, During the coprecipitation reaction, the pH of the reaction system is controlled at 10.1-10.7, the reaction temperature at 65℃-78℃, and the rotation speed at 200-250 r / min.
8. A type of large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide, characterized in that, The large-particle, highly aluminum-doped spherical cobalt hydroxyoxide is obtained by the preparation method of the large-particle, highly aluminum-doped spherical cobalt hydroxyoxide as described in any one of claims 1-7.
9. The large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide according to claim 8, characterized in that, The large-particle, highly aluminum-doped spherical cobalt hydroxyoxide has a particle size D50 ≥ 5 μm and a specific surface area of 2.5-4.5 m². 2 / g, tap density is 2-3g / cm³ 3 Al content ≥ 0.7%.
10. A cobalt tetroxide, characterized in that, The cobalt tetroxide is obtained by calcining the large-particle, highly aluminum-doped spherical cobalt hydroxyl oxide as described in claim 9.