A method for testing the consistency of precursor material conversion and scale-up

Abstract

The present invention discloses a test method for the consistency of precursor material conversion and amplification, and the specific process is that in the experimental stage, a laser particle counter is used to measure the number of crystal nucleus particles per unit volume in the precursor slurry sample in the nucleation stage of the crystallization reaction, which is marked as n1, and the nucleation time is t1; in the conversion and amplification stage, a laser particle counter is used to measure the number of crystal nucleus particles per unit volume in the precursor slurry sample in the nucleation stage of the crystallization reaction, which is marked as n, and when the relative deviation of n and n1 is within ±10%, the time at this moment is the actual nucleation time of the conversion and amplification stage, and the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage under this nucleation time, and the crystal nucleus production stops feeding when the required particle size is reached, and the product conversion and amplification is successful. The present invention has the advantages of high efficiency, low cost, and high accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of battery precursor material conversion and amplification evaluation test methods, and specifically relates to a precursor material conversion and amplification consistency test method. Background Art

[0002] When producing battery precursor materials, the raw metal salt is dissolved in water to form a uniform solution, and then an appropriate precipitant such as sodium hydroxide (NaOH) or ammonia (NH3·H2O) is added to the metal ion solution. Under appropriate temperature and pH conditions, the metal ions combine with hydroxide ions to form crystal nuclei of nickel, cobalt and manganese hydroxide. The nucleation reaction is to control the reaction rate and conditions so that small particles are formed quickly without continuing to grow, thereby obtaining uniform and fine crystal nuclei.

[0003] The research and development of precursor materials needs to go through the process of small-scale testing, pilot-scale testing and small-batch trial production. Scientific researchers engaged in research and development have all had such experience. They have conducted experiments in the laboratory with very good results, but the product conditions when they went to the production site for pilot-scale testing or small-batch trial production were far from what they had imagined.

[0004] The process from laboratory research and development to industrial production is not a simple amplification. It involves process amplification, raw material supply, equipment selection and maintenance, process parameter optimization, quality control, safety and environmental protection, cost control, etc. Among them, process amplification is the most urgent problem to be solved. When the precursor material is converted to production and scaled up, while ensuring that all parameters are scaled up in the same proportion, the theoretical number of nuclei is not necessarily the number of crystal nuclei scaled up in the same proportion, that is, the target product may not be produced within the target time. At present, nucleation time gradient experiments are usually carried out during process transformation, that is, by calculating the growth time during the reaction process to determine whether the nucleation time is appropriate, thereby indirectly determining whether the number of nuclei is appropriate, or referring to the conversion time of similar products for verification. There are often problems such as complex operation, long time consumption, and insufficient accuracy, which are difficult to meet actual production needs. Summary of the invention

[0005] The technical problem solved by the present invention is to provide a method for testing the consistency of precursor material conversion and amplification with high efficiency, low cost and high accuracy.

[0006] In order to solve the above technical problems, the present invention adopts the following technical scheme, which is a testing method for the consistency of precursor material conversion and amplification, and its specific process is: in the experimental stage, a laser particle counter is used to determine the number of crystal nucleus particles per unit volume in the precursor slurry sample in the nucleation stage of the crystallization reaction, marked as n1, and the nucleation time is t1; in the conversion and amplification stage, a laser particle counter is used to determine the number of crystal nucleus particles per unit volume in the precursor slurry sample with a nucleation time of t in the nucleation stage of the crystallization reaction, marked as n, when the relative deviation between n and n1 is within ±10%, the time at this moment is the nucleation time of the conversion and amplification stage, and the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage at this nucleation time, and the feeding is stopped when the crystal nucleus production reaches the required particle size, and the product conversion and amplification is successful.

[0007] It is further defined that the specific process of the production conversion and amplification stage is: the number of crystal nucleus particles per unit volume in the precursor slurry sample with a nucleation time of t1 in the crystallization reaction nucleation stage is measured by a laser particle counter, and is marked as n2. Then the average nucleation number of crystal nucleus particles per unit volume per unit time is m=n2 / t1. The nucleation time required for the crystallization reaction nucleation stage in the production conversion and amplification stage to reach the nucleation standard n1 in the experimental stage is t2=n1 / m. When t2≥t1, the nucleation time is continued to be t2-t1 and the laser particle counter is used to measure the The number of crystal nuclei per unit volume at the nucleation time is marked as n3. The relative deviation between n3 and n1 is within ±10%. The time at this moment is the nucleation time of the production conversion and amplification stage. At this nucleation time, the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage. When the crystal nuclei are produced to the required particle size, the feed is stopped and the product production conversion and amplification are successful. When t2 < t1, the crystal nuclei per unit volume in the precursor slurry sample with a nucleation time of t3 in the crystallization reaction nucleation stage are determined by re-experimentation and using a laser particle counter. The number of particles is marked as n3. If the relative deviation between n3 and n1 is within ±10%, then the time at this moment is the nucleation time of the production conversion and amplification stage. At this nucleation time, the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage. When the crystal nucleus production reaches the required particle size, the feeding is stopped and the product production conversion and amplification are successful. If the relative deviation between n3 and n1 is not within ±10%, the nucleation time is adjusted according to n3. When n3>n1, the nucleation time is reduced by re-experimentation so that the relative deviation between n3 and n1 is within ±10%. , then the time at this moment is the nucleation time, and the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage at this nucleation time. When the crystal nuclei are produced to the required particle size, the feeding is stopped, and the product is successfully scaled up; if n3<n1, the nucleation time is increased so that the relative deviation of n3 and n1 is within ±10%, then the time at this moment is the nucleation time, and the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage at this nucleation time. When the crystal nuclei are produced to the required particle size, the feeding is stopped, and the product is successfully scaled up.

[0008] Further defined, the chemical formula of the precursor material is Ni x Mn y N 1-x-y (OH)2, wherein N is one or more of Ca, Mg, Zn, Co, Cu, Ti, Al, Zr, B, Sr, V, Cr, La, Yb, Ce or Fe, 0<x<1, 0<y<1, 0<x+y≤1.

[0009] It is further stipulated that during the sampling process of the experimental stage and the production conversion and scale-up stage, 6 to 10 samples are taken each time, and the volume of each sample is 50 to 100 mL respectively.

[0010] It is further defined that in the sample processing link of the experimental stage and the production conversion and scale-up stage, 10~50μL of the original solution is taken with a pipette, and diluted 10000~100000 times. The concentration of the dispersant sodium hexametaphosphate solution is 0.5wt%~1wt%, the amount added is 1~5mL, and ultrasonic vibration is performed for 1~5min. After dilution, visual inspection is performed. The judgment standard is to dilute the sample to no color visible to the naked eye. The laser particle counter test recommends 10,000 particles per milliliter.

[0011] It is further defined that during the sample testing phase of the experimental stage and the production scale-up stage, 1 to 10 mL of dilution solution is taken for repeated testing 5 to 10 times, and the average value is taken for analysis.

[0012] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0013] 1. In the preparation of battery precursor materials, as the crystal nuclei are generated, a laser particle counter is used in a suitable time period to accurately calculate the number of crystal nuclei particles per unit volume, and it is inferred whether the reaction process is successfully scaled up on the production line. The current nucleation time gradient experiment requires a nucleation operation at regular intervals (such as 1h, 2h, etc.) to observe the effect of nucleation time on precursor production. It is also necessary to monitor the particle morphology, particle size distribution and other performance changes of the precursor material by sampling and analysis. The experiment requires multiple reactions to be started for verification, and the performance data of the precursor samples prepared at different nucleation times are compared to analyze the influence of nucleation time on the precursor performance. According to the data analysis results, the optimal nucleation time is selected. This method takes a long time, and due to the uncertainty of process parameters and the complexity of operation, test failures or substandard product quality may occur. These failed tests or unqualified products will lead to waste of materials. The test method mentioned in the present invention has the advantages of high efficiency, low cost, low labor and high accuracy.

[0014] 2. The present invention is applicable to the general chemical formula Ni x Mny N 1-x-y The scaled-up test of the (OH)2 precursor material can significantly shorten the product testing cycle by optimizing the testing methods and introducing efficient testing tools, thereby greatly reducing the testing time. The testing time for each sample is about 5 minutes, which not only accelerates the speed of product iteration, but also effectively improves production efficiency, and can bring high-quality products to market faster. At the same time, the reduction in testing time also means a reduction in testing costs, further reducing the company's overall operating costs. This all-round improvement not only enhances market competitiveness, but also lays a solid foundation for the company's sustainable development. DETAILED DESCRIPTION

[0015] The above contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention. Example 1

[0016] 1. Experimental stage: Use 100L reactor to make new product A

[0017] (1) Nickel sulfate, cobalt sulfate, and manganese sulfate were weighed in a molar ratio of 1:1:1, and then dissolved in deionized water to prepare a solution B with a concentration of 2.1 mol / L; at the same time, a 1 mol / L ammonia solution and a 4 mol / L sodium hydroxide solution were prepared;

[0018] (2) Preparation of the bottom pot of the first reactor: Add appropriate amount of pure water, sodium hydroxide solution and ammonia solution to the reactor to make the ammonia content of the bottom pot about 3g / L, the alkali content about 0.6g / L, and the pH between 12.10 and 12.20. Introduce nitrogen at a flow rate of 2L / min. At a normal speed and temperature, inject solution B and sodium hydroxide solution into the first reactor at a constant flow rate of 150mL / min and 50mL / min, respectively, for reaction. The first hour of the reaction is the nucleation stage. When the reaction is carried out for 1 hour, adjust the pH to 7-9 for the crystal nucleus growth stage. When the final reaction time is 49.5h, D50 grows to 4-4.1μm, at which time the required particle size is reached and all feeding is stopped.

[0019] (3) Particle number test

[0020] When the reaction was carried out for 1 hour, 10 portions of slurry were extracted from the reserved port of the reactor using a peristaltic pump, each with a volume of 50 mL.

[0021] While ensuring that the liquid is uniform, use a pipette to accurately transfer 10 μL of the stock solution into the sample pool and dilute it to 100 mL. Add 1 mL of 1 wt% sodium hexametaphosphate solution and perform ultrasonic vibration for 1 min.

[0022] After ensuring that the equipment is in good working condition, start measuring and test 10 samples one by one.

[0023] The test results are as follows:

[0024]

[0025] From this we know that the number of crystal nuclei per microliter of the precursor slurry produced by this process is 2429470. The process is now scaled up to the production line.

[0026] 2. Production conversion and expansion stage: Use 3000L reactor to produce new product A

[0027] (1) Nickel sulfate, cobalt sulfate, and manganese sulfate were weighed in a molar ratio of 1:1:1, and then dissolved in deionized water to prepare a solution C with a concentration of 2.1 mol / L; at the same time, a 1 mol ammonia solution and a 4 mol / L sodium hydroxide solution were prepared;

[0028] (2) Preparation of the bottom pot of the second reactor: Add an appropriate amount of pure water, sodium hydroxide solution and ammonia solution to the reactor, so that the ammonia content of the bottom pot is about 3 g / L, the alkali content is about 0.6 g / L, and the pH is 12.10-12.20. Pass nitrogen gas, and inject solution C and sodium hydroxide solution into the second reactor at a constant flow rate of 4.5 L / min and 1.5 L / min, respectively, at a normal speed and temperature for reaction. Stop the reaction after 1 hour and count the particles.

[0029] (3) Particle number test

[0030] After 1 h of reaction, 10 portions of slurry were extracted from the reserved port of the reactor using a peristaltic pump, each with a volume of 50 mL.

[0031] Accurately transfer 10 μL of the stock solution into the sample pool and dilute to 100 mL. Add 1 mL of 1 wt% sodium hexametaphosphate solution and ultrasonically vibrate for 1 min.

[0032] Make sure the equipment is in good working condition, start measuring, and test 10 samples one by one.

[0033] The test results are as follows:

[0034]

[0035] According to the test, the number of particles per microliter of slurry is 1927200, while the theoretical number of particles per microliter of slurry after 1 hour of nucleation after scale-up production is about 2429470. Therefore, if nucleation is carried out for 1 hour after scale-up, the number of nucleated particles is relatively small, with 502270 fewer crystal nucleus particles per microliter.

[0036] According to the actual number of nucleation particles produced in 1 hour, the number of crystal nucleus particles per microliter of slurry is 192720. Therefore, 3212 crystal nucleus particles will be produced in one microliter of slurry per minute, and it will take another 15 minutes, or 0.26 hours, to produce 502270 crystal nucleus particles. Therefore, according to the proportion of the number of nucleation particles, theoretically, it should take 1.26 hours to produce nuclei, so it is still necessary to produce nuclei for 0.26 hours.

[0037] (4) Maintaining the original process parameters, the reaction was continued for 0.26 h. After the nucleation was completed, the number of crystal nuclei was tested in the same manner as described in (3).

[0038] The test results are as follows:

[0039]

[0040] According to the test results: the number of particles per microliter of slurry is 2646400, while the number of particles per microliter of slurry after theoretical scale-up production for 1 hour is about 2429470. It is believed that the deviation between the actual number of particles and the theoretical number of particles is within the allowable error range (±10%). Therefore, the pH is reduced from 12.10~12.20 to 7~9 for the crystal nucleus growth stage. When the reaction time is 55h, the D50 of the precursor particles grows to 4.15μm, at which time the required particle size is reached, the target product is generated, and all feeds are stopped. It is believed that this precursor material has been successfully scaled up.

[0041] If the relative deviation between the actual number of particles and the theoretical number of particles is not within the allowable error range (±10%), the nucleation time is adjusted according to the actual number of particles. When the actual number of particles is greater than the theoretical number of particles, the nucleation time is reduced by re-experimentation so that the relative deviation between the actual number of particles and the theoretical number of particles is within the allowable error range (±10%). The time at this moment is the nucleation time. At this nucleation time, the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage. When the crystal nuclei are produced to the required particle size, the feeding is stopped, and the product is successfully scaled up. When the actual number of particles is less than the theoretical number of particles, the nucleation time is increased so that the relative deviation between the actual number of particles and the theoretical number of particles is within the allowable error range (±10%). The time at this moment is the nucleation time. At this nucleation time, the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage. When the crystal nuclei are produced to the required particle size, the feeding is stopped, and the product is successfully scaled up.

[0042] This method can ensure real-time or regular sampling for particle counting during the sample production process, ensure timely acquisition of information on the nucleation period, and provide data support for process adjustment and optimization. Generally, problems with production conversion and scale-up can be found within 5 hours of reaction, while the traditional method requires judging whether the nucleation period setting is reasonable by the particle size growth rate at 15 to 20 hours. In summary, the present invention uses a laser particle counter to quickly determine the nucleation period of the precursor material, which has the advantages of high efficiency, accuracy, comprehensiveness, automation and intelligence.

[0043] The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for testing the consistency of precursor material conversion and amplification, characterized in that The specific process is as follows: in the experimental stage, a laser particle counter is used to measure the number of crystal nucleus particles per unit volume in the precursor slurry sample in the nucleation stage of the crystallization reaction, which is marked as n1, and the nucleation time is t1; During the conversion and scale-up stage, a laser particle counter is used to measure the number of crystal nucleus particles per unit volume in the precursor slurry sample with a nucleation time of t in the nucleation stage of the crystallization reaction, and the number is marked as n. When the relative deviation between n and n1 is within ±10%, the time at this moment is the nucleation time of the conversion and scale-up stage. At this nucleation time, the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage. When the crystal nucleus production reaches the required particle size, the feeding is stopped and the product conversion and scale-up is successful.

2. The method for testing the consistency of precursor material conversion and amplification according to claim 1, characterized in that The specific process of the production conversion and amplification stage is: the number of crystal nucleus particles per unit volume in the precursor slurry sample with a nucleation time of t1 in the crystallization reaction nucleation stage is measured by a laser particle counter and marked as n2, then the average nucleation number of crystal nucleus particles per unit volume per unit time is m=n2 / t1, and the nucleation time required for the crystallization reaction nucleation stage in the production conversion and amplification stage to reach the nucleation standard n1 in the experimental stage is t2=n1 / m, when t2≥t1, the nucleation time t2-t1 is continued and the corresponding nucleation time is measured by the laser particle counter The number of crystal nuclei per unit volume under the condition of t2 is marked as n3, and the relative deviation between n3 and n1 is within ±10%. The time at this moment is the nucleation time of the production conversion and amplification stage. Under this nucleation time, the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage. When the crystal nucleus production reaches the required particle size, the feeding is stopped, and the product production conversion and amplification are successful. When t2 < t1, the number of crystal nuclei per unit volume in the precursor slurry sample with the nucleation time of t3 in the crystallization reaction nucleation stage is determined by re-experimentation and using a laser particle counter. The quantity is marked as n3, and the relative deviation of n3 and n1 is within ±10%. The time at this moment is the nucleation time of the production conversion and amplification stage. Under this nucleation time, the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage. When the crystal nucleus production reaches the required particle size, the feeding is stopped, and the product production conversion and amplification are successful; if the relative deviation of n3 and n1 is not within ±10%, the nucleation time is adjusted according to n3. When n3>n1, the nucleation time is reduced by re-experimentation so that the relative deviation of n3 and n1 is within ±10%, then The time at this moment is the nucleation time. At this nucleation time, the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage. When the crystal nuclei are produced to the required particle size, the feeding is stopped, and the product is successfully scaled up. If n3<n1, the nucleation time is increased so that the relative deviation of n3 and n1 is within ±10%. The time at this moment is the nucleation time. At this nucleation time, the pH corresponding to the nucleation stage is adjusted to the pH corresponding to the crystal nucleus growth stage. When the crystal nuclei are produced to the required particle size, the feeding is stopped, and the product is successfully scaled up.

3. The method for testing the consistency of precursor material conversion and amplification according to claim 1, characterized in that: The chemical formula of the precursor material is Ni x Mn y N 1-x-y (OH)2, wherein N is one or more of Ca, Mg, Zn, Co, Cu, Ti, Al, Zr, B, Sr, V, Cr, La, Yb, Ce or Fe, 0<x<1, 0<y<1, 0<x+y≤1.

4. The method for testing the consistency of precursor material conversion and amplification according to claim 1, characterized in that: During the sampling process in the experimental stage and the production conversion and scale-up stage, 6 to 10 samples are taken each time, and the volume of each sample is 50 to 100 mL.

5. The method for testing the consistency of precursor material conversion and amplification according to claim 1, characterized in that: In the sample processing link of the experimental stage and the production conversion and scale-up stage, 10 to 50 μL of the original solution is taken with a pipette, diluted 10,000 to 100,000 times, the concentration of the dispersant sodium hexametaphosphate solution is 0.5wt% to 1wt%, the amount added is 1 to 5mL, and ultrasonic vibration is performed for 1 to 5 minutes. After dilution, visual inspection is performed, and the judgment standard is that the sample is diluted to no color visible to the naked eye.

6. The method for testing the consistency of precursor material conversion and amplification according to claim 1, characterized in that: During the sample testing phase of the experimental stage and the production scale-up stage, 1 to 10 mL of dilution solution is taken for repeated testing 5 to 10 times, and the average value is taken for analysis.

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