Preparation method of high-BET high-nickel low-cobalt ternary large-particle precursor

Abstract

The invention discloses a preparation method of a high-BET high-nickel low-cobalt ternary large-particle precursor, the preparation of high-BET and high-tap-density ternary large-particle precursor is realized by controlling multiple devices and reaction nodes, the synthesis operation in the whole process is simple, the yield is high, and the complex process is simplified through multiple steps; and meanwhile, the process also has the advantage of high productivity, and the reaction efficiency can be better improved by reasonably utilizing equipment, so that the yield of the ternary precursor is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of electrode material preparation, and in particular to a method for preparing a high-BET high-nickel low-cobalt ternary large-particle precursor. Background Art

[0002] With the rapid development of new energy vehicles, the lithium battery industry is demanding increasingly higher standards. Common lithium batteries are primarily divided into lithium iron phosphate (LFP) and ternary lithium batteries. Ternary lithium batteries have a higher market share and are being researched more extensively due to their advantages, including higher energy density, greater power, and greater adaptability. Traditional ternary lithium batteries primarily refer to nickel-cobalt-manganese (NiCoMn) batteries. Due to the inherent nature of batteries, any parameter of the ternary precursor material can affect battery performance. Sphericity and tap density are two key indicators for evaluating precursors.

[0003] Patent CN202310911264 discloses a high-BET, high-nickel, low-cobalt ternary large-particle precursor and its preparation method and application. A mixed solution of Ni, Co, and Mn sulfates, ammonia water, and NaOH solution are added to a reactor with a bottom liquid at the same time. The temperature and stirring speed are controlled to carry out a co-precipitation reaction. The ammonia concentration of the supernatant in the reactor is controlled to allow the crystalline particles to grow to a qualified particle size, and then the feeding reaction is stopped to obtain a high-nickel, low-cobalt ternary large-particle precursor.

[0004] Due to the small feed flow rate, the number of finished products obtained by this patented technology is also small, which is not suitable for large-scale production; and due to the severe cracking of the particles, the slurry needs to be aged, which will result in a high residual Na / s in the particles, affecting the subsequent sintering of the positive electrode, thereby reducing the capacity and cycle number of the battery; the product obtained by this patent has a high specific surface area, and the specific surface area is generally inversely proportional to the tap density, that is, the larger the specific surface area, the lower the tap density, and the high specific surface area will inevitably affect the tap density, thereby reducing the charge and discharge and cycle performance.

[0005] Based on this, a method for preparing a large-particle ternary precursor with good sphericity, high tap density, high specific surface area and high nickel content is needed. Summary of the Invention

[0006] The purpose of the present invention is to provide a high-BET high-nickel low-cobalt ternary large particle precursor and a preparation method thereof.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention includes the following steps: A method for preparing a high-BET, high-nickel, low-cobalt ternary large-particle precursor, comprising the following steps: (1) nickel sulfate, cobalt sulfate and manganese sulfate are prepared into a nickel-cobalt-manganese salt solution with a total metal ion concentration of 2 mol / L, a sodium hydroxide solution with a concentration of 10-11 mol / L, and an ammonia solution with a concentration of 7.3-7.7 mol / L; (2) A sealed 2m³ reactor was introduced with nitrogen protective gas at a rate of 2~3m³ / h and a nitrogen flow rate of 5~6m³ / h. During the process, 0.95~1.05m³ of pure water was added to the reactor, and stirring was started at 340rpm. The temperature was controlled at 48~52℃. (3) Add ammonia water to the reactor, control the ammonia value at 3.0~5.0g / L, and add alkali solution to adjust the pH of the system to 10.7~11.5, which serves as the base liquid and starting condition for the reaction; (4) Nickel-cobalt-manganese salt solution, sodium hydroxide solution and ammonia solution were fed at flow rates of 60-80 L / h, 20.5-30 L / h and 5-8 L / h, respectively, and simultaneously added to the reactor while maintaining inert gas flow. During this period, the system pH was maintained at 10.7-11.5 and the ammonia value was 3.0-5.0 g / L. After 60 min, the pH was reduced to 10.3-10.7, and the rotation speed was reduced to 300-320 rpm. The reaction temperature remained unchanged. (5) When the reaction particle size D50 is 1.2~1.6μm, reduce the speed to 290~320rpm; when D50 is 2~2.2μm, reduce the speed to 270~300rpm; when D50 is 2.5~2.7μm, reduce the speed to 260~280rpm; (6) When the reaction particle size D50 is 2.6~3.0um, stop feeding and wait for 30 minutes. After retesting the reaction particle size and finding no problem, transfer the 2m³ kettle material to the 10m³ kettle and continue to start the machine; (7) After the material is transferred to the 10m³ reactor, 3~4m³ of pure water is added to the reactor, and nitrogen protective gas is introduced into the sealed 2m³ reactor at a rate of 2~4m³ / h and a nitrogen flow rate of 5~6m³ / h. Stirring is started at a speed of 240~260rpm, the temperature is controlled at 48~52℃, the ammonia value is controlled at 3.0~4.0g / L, and alkali solution is added to adjust the pH of the system to 10.5~10.7, which serves as the base liquid and starting condition for the reaction; (8) The nickel-cobalt-manganese salt solution, sodium hydroxide solution and ammonia solution were fed at flow rates of 300 L / h, 110 L / h and 15 L / h, respectively, and simultaneously added to the reactor while maintaining the inert gas flow. During this period, the system pH was maintained at 10.5-10.7 and the ammonia value was maintained at 3.0-4.0 g / L. When the reaction particle size D50 was 3.0 μm, the speed was reduced to 240 rpm; when D50 was 4.0 μm, the speed was reduced to 220 rpm; when D50 was 6.0 μm, the speed was reduced to 200 rpm. (9) When the reaction particle size D50 is 6.0 μm, stop feeding and wait for 30 min. After retesting the reaction particle size and finding no problem, discharge the material in the 10 m³ kettle into the aging tank for washing. After washing, pack the solid filter cake, protect it well, and take a sample to measure the moisture content of the filter cake. (10) Continue to start the 10m³ reactor and re-take 200~300kg of filter cake and put it back into the reactor. After putting it into the reactor, add 5m³ of pure water, and then adjust the liquid to pass the upper and lower nitrogen protection gas 2~3m³ / h, the lower nitrogen flow rate is 5~6m³ / h, start stirring at 200rpm, control the temperature to 48~52℃, control the ammonia value to 3.0~4.0g / L, add alkali solution to adjust the pH of the system to 9.8~10.2, as the base liquid and starting condition for the start of the reaction; (11) Nickel-cobalt-manganese salt solution, sodium hydroxide solution and ammonia solution were fed into the reactor at flow rates of 600 L / h, 200 L / h and 30 L / h respectively, and inert gas was introduced into the reactor at the same time. During this period, the pH of the system was maintained at 10.3-10.7 and the ammonia value was maintained at 3.0-5.0 g / L. The rotation speed and compressed air flow rate were adjusted according to the reaction particle size D50. (12) When the reaction particle size D50 is 16.0~18.0um, stop feeding and wait for 30 minutes. After retesting the reaction particle size and finding no problem, discharge the material in the 10m³ kettle into the aging tank for washing. During washing, the alkali temperature is 60~65℃, the amount of alkali used is 1~3m³, the washing water temperature is 70~75℃, and the amount of washing water is 5~10m³. After washing, spin dry at high speed for more than 2 hours and then unload. (13) After washing, put the material into the drying oven and dry it at 100-110℃ for 6 hours. After turning the material over once, heat it to 110-120℃ and dry it for 6 hours. (14) The dried samples with qualified moisture content are mixed, screened, demagnetized, and packaged to obtain the finished product.

[0008] Furthermore, the molar ratio of nickel, cobalt and manganese in the nickel-cobalt-manganese salt solution in step (1) is 95:4:1, and its mass concentration is 114.6 g / L.

[0009] Furthermore, the speed adjustment in step (11) is specifically as follows: When D50 is 9.0μm, reduce the speed to 170~190rpm; when D50 is 10.0~11.0μm, reduce the speed to 130~140rpm; when D50 is 13.0μm, reduce the speed to 100~110rpm; when D50 is 15.0μm, reduce the speed to 80~100rpm; when D50 is 17.0μm, reduce the speed to 65rpm.

[0010] Furthermore, in step (11), the compressed air flow rate is adjusted as follows: When D50 is 8.0~9.0μm, the compressed air flow rate is 1.0~1.5m³ / h; when D50 is 10.0~11.0μm, the compressed air flow rate is 2.5~3.0m³ / h; when D50 is 12.0~13.0μm, the compressed air flow rate is 4.0~5.0m³ / h; when D50 is 14.0~15.0μm, the compressed air flow rate is 6.0~7.0m³ / h.

[0011] The beneficial effects of the present invention are: 1. The present invention achieves the preparation of large particles of ternary precursors with high BET and high tap density by controlling multiple devices and reaction nodes. The entire synthesis process is simple to operate and has a high yield. The complex process is simplified through multiple steps. At the same time, this process also has the advantage of high production capacity. Through the rational use of equipment, the reaction efficiency can be greatly improved, thereby ensuring the yield of the ternary precursor. 2. The particles prepared by the present invention have a narrow distribution. After granulation, coprecipitation, centrifugal washing and drying, a spherical high nickel ternary precursor product with both tap density and specific surface area is obtained, and the tap density is high TD>2.0g / cm 3 , the ratio is between 16 and 20m 2 / g. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is the SEM image (1k) of the ternary precursor obtained in Example 1 of the present invention.

[0013] Figure 2 This is a cross-sectional view of the ternary precursor obtained in Example 1.

[0014] Figure 3 This is the SEM image of the ternary precursor obtained in Example 2 (1k).

[0015] Figure 4 This is a cross-sectional view of the ternary precursor obtained in Example 2. DETAILED DESCRIPTION

[0016] The present invention will be further described in detail below with reference to the embodiments.

[0017] Example 1 (1) nickel sulfate, cobalt sulfate and manganese sulfate are prepared into a nickel-cobalt-manganese salt solution with a total metal ion concentration of 2 mol / L (114.6 g / L), a sodium hydroxide solution with a concentration of 10.5 mol / L, and an ammonia solution with a concentration of 7.5 mol / L; (2) A sealed 2m³ reactor was introduced with nitrogen protective gas at a rate of 2.5m³ / h and a nitrogen flow rate of 5.5m³ / h. During the process, 1m³ of pure water was added to the reactor, and stirring was started at a speed of 340rpm. The temperature was controlled at 50°C. (3) Add ammonia water to the reactor, control the ammonia value at 3.5 g / L, and add alkali solution to adjust the pH of the system to 11.2, which serves as the base liquid and starting condition for the reaction; (4) Nickel-cobalt-manganese salt solution, sodium hydroxide solution and ammonia solution were fed at flow rates of 60 L / h, 20.5 L / h and 5 L / h, respectively, and added to the reactor simultaneously while maintaining inert gas flow. During this period, the system pH was maintained at 11.2 and the ammonia value was 3.5 g / L. After 60 min, the pH was reduced to 10.6, and the rotation speed was reduced to 320 rpm. The reaction temperature remained unchanged. (5) When the reaction particle size D50 is 1.2 μm, reduce the speed to 320 rpm; when D50 is 2 μm, reduce the speed to 300 rpm; when D50 is 2.5 μm, reduce the speed to 280 rpm; (6) When the reaction particle size D50 is 2.6 μm, stop feeding and wait for 30 minutes. After retesting the reaction particle size and finding no problem, transfer the 2 m³ kettle material to the 10 m³ kettle and continue to start the machine. (7) After the material is transferred to the 10m³ reactor, 4m³ of pure water is added to the reactor, and 2.5m³ / h of nitrogen protective gas is introduced into the sealed 2m³ reactor, with a nitrogen flow rate of 5.5m³ / h. Stirring is started at 260rpm, the temperature is controlled at 50℃, the ammonia value is controlled at 3.5g / L, and alkali solution is added to adjust the pH of the system to 10.6, which serves as the base liquid and starting condition for the reaction; (8) The nickel-cobalt-manganese salt solution, sodium hydroxide solution and ammonia solution were fed at flow rates of 300 L / h, 110 L / h and 15 L / h, respectively, and added to the reactor at the same time while maintaining the inert gas flow. During this period, the system pH was maintained at 10.6 and the ammonia value was maintained at 3.5 g / L. When the reaction particle size D50 was 3.0 μm, the speed was reduced to 240 rpm; when D50 was 4.0 μm, the speed was reduced to 220 rpm; when D50 was 6.0 μm, the speed was reduced to 200 rpm; (9) When the reaction particle size D50 is 6.0 μm, stop feeding and wait for 30 min. After retesting the reaction particle size and finding no problem, discharge the material in the 10 m³ kettle into the aging tank for washing. After washing, pack the solid filter cake, protect it well, and take a sample to measure the moisture content of the filter cake. (10) Continue to start the 10m³ reactor and re-take 250kg of filter cake and put it back into the reactor. After putting it into the reactor, add 5m³ of pure water, and then adjust the liquid to pass the upper and lower nitrogen protection gas at 2.5m³ / h, the lower nitrogen flow rate is 5.5m³ / h, start stirring at 200rpm, control the temperature to 50℃, control the ammonia value to 3.5g / L, add alkali solution to adjust the pH of the system to 10.0, as the base liquid and starting condition for the start of the reaction; (11) Nickel-cobalt-manganese salt solution, sodium hydroxide solution and ammonia solution were fed at flow rates of 600 L / h, 200 L / h and 30 L / h, respectively, and simultaneously added to the reactor while maintaining inert gas flow. During this period, the system pH was maintained at 10.6 and the ammonia value was maintained at 3.5 g / L. The rotation speed and compressed air flow rate were adjusted according to the reaction particle size D50. (12) When D50 is 9.0 μm, reduce the speed to 190 rpm; when D50 is 11.0 μm, reduce the speed to 140 rpm; when D50 is 13.0 μm, reduce the speed to 110 rpm; when D50 is 15.0 μm, reduce the speed to 100 rpm; (13) When D50 is 9.0 μm, the compressed air flow rate is 1.0 m³ / h; when D50 is 11.0 μm, the compressed air flow rate is 3.0 m³ / h; when D50 is 13.0 μm, the compressed air flow rate is 5.0 m³ / h; when D50 is 15.0 μm, the compressed air flow rate is 7.0 m³ / h; (14) When the reaction particle size D50 is 16.0 μm, stop feeding and wait for 30 min. After retesting the reaction particle size and finding no problem, discharge the material in the 10 m³ kettle into the aging tank for washing. During washing, the alkali temperature is 63 ° C, the alkali dosage is 2 m³, the washing water temperature is 72 ° C, and the washing water dosage is 8 m³. After washing, spin dry at high speed for more than 2 h, and then unload. (15) After washing, put the material into the oven and dry it at 100℃ for 6 hours. After turning the material over once, heat it to 110℃ and dry it for 6 hours. (16) The dried samples with qualified moisture content are mixed, screened, demagnetized, and packaged to obtain the finished product.

[0018] Example 2 (1) nickel sulfate, cobalt sulfate and manganese sulfate are prepared into a nickel-cobalt-manganese salt solution with a total metal ion concentration of 2 mol / L (114.6 g / L), a sodium hydroxide solution with a concentration of 11 mol / L, and an ammonia solution with a concentration of 7.3 mol / L; (2) A sealed 2m³ reactor was introduced with a nitrogen protective gas flow rate of 2m³ / h and a nitrogen flow rate of 6m³ / h. During the process, 1.05m³ of pure water was added to the reactor, and stirring was started at a speed of 340rpm. The temperature was controlled at 48°C. (3) Add ammonia water to the reactor, control the ammonia value at 4.5 g / L, and add alkali solution to adjust the pH of the system to 10.7, which serves as the base liquid and starting condition for the reaction; (4) Nickel-cobalt-manganese salt solution, sodium hydroxide solution and ammonia solution were fed at flow rates of 80 L / h, 30 L / h and 8 L / h, respectively, and simultaneously added to the reactor while maintaining inert gas flow. During this period, the system pH was maintained at 10.7 and the ammonia value was 4.5 g / L. After 60 min, the pH was reduced to 10.4, and the rotation speed was reduced to 300 rpm. The reaction temperature remained unchanged. (5) When the reaction particle size D50 is 1.6 μm, reduce the speed to 290 rpm; when D50 is 2.2 μm, reduce the speed to 270 rpm; when D50 is 2.7 μm, reduce the speed to 260 rpm; (6) When the reaction particle size D50 is 3.0 μm, stop feeding and wait for 30 minutes. After retesting the reaction particle size and finding no problem, transfer the 2 m³ kettle material to the 10 m³ kettle and continue to start the machine. (7) After the material is transferred to the 10m³ reactor, 3m³ of pure water is added to the reactor, and 3.5m³ / h of nitrogen protective gas is introduced into the sealed 2m³ reactor, with a nitrogen flow rate of 5m³ / h. Stirring is started at 240rpm, the temperature is controlled at 52°C, the ammonia value is controlled at 3.5g / L, and alkali solution is added to adjust the pH of the system to 10.6, which serves as the base liquid and starting condition for the reaction; (8) The nickel-cobalt-manganese salt solution, sodium hydroxide solution and ammonia solution were fed at flow rates of 300 L / h, 110 L / h and 15 L / h, respectively, and added to the reactor at the same time while maintaining the inert gas flow. During this period, the system pH was maintained at 10.5 and the ammonia value was maintained at 4.0 g / L. When the reaction particle size D50 was 3.0 μm, the speed was reduced to 240 rpm; when D50 was 4.0 μm, the speed was reduced to 220 rpm; when D50 was 6.0 μm, the speed was reduced to 200 rpm; (9) When the reaction particle size D50 is 6.0 μm, stop feeding and wait for 30 min. After retesting the reaction particle size and finding no problem, discharge the material in the 10 m³ kettle into the aging tank for washing. After washing, pack the solid filter cake, protect it well, and take a sample to measure the moisture content of the filter cake. (10) Continue to start the 10m³ reactor and re-take 300kg of filter cake and put it back into the reactor. After putting it into the reactor, add 5m³ of pure water, and then adjust the liquid to pass through the upper and lower nitrogen protection gas at 3m³ / h, the lower nitrogen flow rate is 5m³ / h, start stirring at 200rpm, control the temperature to 52℃, control the ammonia value to 3.0g / L, add alkali solution to adjust the system pH to 10.2, as the base liquid and starting condition for the start of the reaction; (11) Nickel-cobalt-manganese salt solution, sodium hydroxide solution and ammonia solution were fed at flow rates of 600 L / h, 200 L / h and 30 L / h, respectively, and simultaneously added to the reactor while maintaining inert gas flow. During this period, the system pH was maintained at 10.4 and the ammonia value was maintained at 4.5 g / L. The rotation speed and compressed air flow rate were adjusted according to the reaction particle size D50. (12) When D50 is 9.0 μm, reduce the speed to 170 rpm; when D50 is 10.0 μm, reduce the speed to 130 rpm; when D50 is 13.0 μm, reduce the speed to 100 rpm; when D50 is 15.0 μm, reduce the speed to 80 rpm; when D50 is 17.0 μm, reduce the speed to 65 rpm; (13) When D50 is 8.0 μm, the compressed air flow rate is 1.5 m³ / h; when D50 is 10.0 μm, the compressed air flow rate is 2.5 m³ / h; when D50 is 12.0 μm, the compressed air flow rate is 4.0 m³ / h; when D50 is 14.0 μm, the compressed air flow rate is 6.0 m³ / h; (14) When the reaction particle size D50 is 18.0 μm, stop feeding and wait for 30 min. After retesting the reaction particle size and finding no problem, discharge the material in the 10 m³ kettle into the aging tank for washing. During washing, the alkali temperature is 65 ° C, the amount of alkali used is 1 m³, the washing water temperature is 70 ° C, and the amount of washing water is 10 m³. After washing, spin dry at high speed for more than 2 hours and then unload. (15) After washing, put the material into the oven and dry it at 110℃ for 6 hours. Turn the material over once and then heat it to 120℃ and dry it for 6 hours. (16) The dried samples with qualified moisture content are mixed, screened, demagnetized, and packaged to obtain the finished product.

[0019] The D50, BET and TD of the ternary precursor products prepared in Example 1 and Example 2 were measured. The specific data are shown in Table 1.

[0020] Table 1 Key physical and chemical indicators of the ternary precursors obtained in Example 1 and Example 2

Claims

1. A method for preparing a high-BET high-nickel low-cobalt ternary large particle precursor, characterized by: The specific steps are: (1) nickel sulfate, cobalt sulfate and manganese sulfate are prepared into a nickel-cobalt-manganese salt solution with a total metal ion concentration of 2 mol / L, a sodium hydroxide solution with a concentration of 10-11 mol / L, and an ammonia solution with a concentration of 7.3-7.7 mol / L; (2) A sealed 2m³ reactor was introduced with nitrogen protective gas at a rate of 2~3m³ / h and a nitrogen flow rate of 5~6m³ / h. During the process, 0.95~1.05m³ of pure water was added to the reactor, and stirring was started at 340rpm. The temperature was controlled at 48~52℃. (3) Add ammonia water to the reactor, control the ammonia value at 3.0~5.0g / L, and add alkali solution to adjust the pH of the system to 10.7~11.5, which serves as the base liquid and starting condition for the reaction; (4) The nickel-cobalt-manganese salt solution, sodium hydroxide solution, and ammonia solution were simultaneously fed at flow rates of 60-80 L / h, 20.5-30 L / h, and 5-8 L / h, respectively, and inert gas was maintained. During this period, the system pH was maintained at 10.7-11.5 and the ammonia value was maintained at 3.0-5.0 g / L. After 60 minutes, the pH was reduced to 10.3-10.7, and the rotation speed was reduced to 300-320 rpm. The reaction temperature remained unchanged. (5) When the reaction particle size D50 is 1.2~1.6μm, reduce the speed to 290~320rpm; when D50 is 2~2.2μm, reduce the speed to 270~300rpm; when D50 is 2.5~2.7μm, reduce the speed to 260~280rpm; (6) When the reaction particle size D50 is 2.6~3.0um, stop feeding and wait for 30 minutes. After retesting the reaction particle size and finding no problem, transfer the 2m³ kettle material to the 10m³ kettle and continue to start the machine; (7) After the material is transferred to the 10m³ reactor, 3~4m³ of pure water is added to the reactor, and nitrogen protective gas is introduced into the sealed 2m³ reactor at a rate of 2~4m³ / h and a nitrogen flow rate of 5~6m³ / h. Stirring is started at a speed of 240~260rpm, the temperature is controlled at 48~52℃, the ammonia value is controlled at 3.0~4.0g / L, and alkali solution is added to adjust the pH of the system to 10.5~10.7, which serves as the base liquid and starting condition for the reaction; (8) Add nickel-cobalt-manganese salt solution, sodium hydroxide solution and ammonia solution to the reactor at flow rates of 300 L / h, 110 L / h and 15 L / h respectively, and maintain the inert gas flow. During this period, the system pH is maintained at 10.5-10.7 and the ammonia value is maintained at 3.0-4.0 g / L. When the reaction particle size D50 is 3.0 μm, reduce the speed to 240 rpm; when D50 is 4.0 μm, reduce the speed to 220 rpm; when D50 is 6.0 μm, reduce the speed to 200 rpm; (9) When the reaction particle size D50 is 6.0 μm, stop feeding and wait for 30 min. After retesting the reaction particle size and finding no problem, discharge the material in the 10 m³ kettle into the aging tank for washing. After washing, pack the solid filter cake, protect it well, and take a sample to measure the moisture content of the filter cake. (10) Continue to start the 10m³ reactor and re-take 200~300kg of filter cake and put it back into the reactor. After putting it into the reactor, add 5m³ of pure water, and then adjust the liquid to pass the upper and lower nitrogen protection gas 2~3m³ / h, the lower nitrogen flow rate is 5~6m³ / h, start stirring at 200rpm, control the temperature to 48~52℃, control the ammonia value to 3.0~4.0g / L, add alkali solution to adjust the pH of the system to 9.8~10.2, as the base liquid and starting condition for the start of the reaction; (11) Add nickel-cobalt-manganese salt solution, sodium hydroxide solution and ammonia solution to the reactor at flow rates of 600 L / h, 200 L / h and 30 L / h respectively, and maintain the inert gas flow. During this period, the system pH is maintained at 10.3-10.7, the ammonia value is maintained at 3.0-5.0 g / L, and the rotation speed and compressed air flow rate are adjusted according to the reaction particle size D50; (12) When the reaction particle size D50 is 16.0~18.0um, stop feeding and wait for 30 minutes. After retesting the reaction particle size and finding no problem, discharge the material in the 10m³ kettle into the aging tank for washing. During washing, the alkali temperature is 60~65℃, the amount of alkali used is 1~3m³, the washing water temperature is 70~75℃, and the amount of washing water is 5~10m³. After washing, spin dry at high speed for more than 2 hours and then unload. (13) After washing, put the material into the drying oven and dry it at 100-110℃ for 6 hours. After turning the material over once, heat it to 110-120℃ and dry it for 6 hours. (14) The dried samples with qualified moisture content are mixed, screened, demagnetized, and packaged to obtain the finished product.

2. The method for preparing a high-BET high-nickel low-cobalt ternary large particle precursor according to claim 1, characterized in that: The molar ratio of nickel, cobalt and manganese in the nickel-cobalt-manganese salt solution is 95:4:1, and its mass concentration is 114.6 g / L.

3. The method for preparing a high-BET high-nickel low-cobalt ternary large particle precursor according to claim 1, characterized in that: The speed adjustment in step (11) is specifically as follows: When D50 is 9.0μm, reduce the speed to 170~190rpm; when D50 is 10.0~11.0μm, reduce the speed to 130~140rpm; when D50 is 13.0μm, reduce the speed to 100~110rpm; when D50 is 15.0μm, reduce the speed to 80~100rpm; when D50 is 17.0μm, reduce the speed to 65rpm.

4. The method for preparing a high-BET high-nickel low-cobalt ternary large particle precursor according to claim 1, characterized in that: The compressed air flow rate is adjusted in step (11) as follows: When D50 is 8.0~9.0μm, the compressed air flow rate is 1.0~1.5m³ / h; when D50 is 10.0~11.0μm, the compressed air flow rate is 2.5~3.0m³ / h; when D50 is 12.0~13.0μm, the compressed air flow rate is 4.0~5.0m³ / h; when D50 is 14.0~15.0μm, the compressed air flow rate is 6.0~7.0m³ / h.

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