A testing method for the solid content of a ternary precursor slurry

Abstract

The present invention provides a method for testing the solid content of a ternary precursor slurry, and the solid content is calculated by Equation 1: In Equation 1, S is the solid content; m is the mass of the slurry sample to be tested; V is the volume of the slurry sample to be tested; ρ 1 is the density of the clear liquid in the slurry sample to be tested; ρ 2 is the density of the solid phase in the slurry sample to be tested. The method for testing the solid content of the ternary precursor slurry provided by the present invention calculates the solid content of the ternary precursor slurry through a formula, and has relatively high accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of chemical analysis, and in particular to a method for testing the solid content of a ternary precursor slurry. Background Art

[0002] Ternary precursors are key materials for the preparation of ternary cathode materials. Currently, most ternary precursor materials are nickel-cobalt-manganese ternary precursors. In the lithium battery cathode industry chain, the final performance of the cathode material will inherit the morphological characteristics of its precursor. The quality of the precursor (morphology, particle size, particle size distribution, specific surface area, impurity content, tap density, etc.) directly determines the physical and chemical indicators of the cathode sintered product.

[0003] The control of solid content during the synthesis of ternary precursors will directly affect the product morphology, tap density, specific surface area and other properties. In the prior art, the solid content in the ternary precursor slurry is tested by decantation, but the operation of the decantation method requires subjective judgment by humans, and the human factor has a great influence, resulting in insufficient accuracy. Therefore, developing a method that can accurately test the solid content in the ternary precursor slurry is a problem that needs to be solved urgently. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for testing the solid content of a ternary precursor slurry, which can accurately test the solid content of the ternary precursor slurry.

[0005] The present invention provides a method for testing the solid content of a ternary precursor slurry, wherein the solid content is calculated by formula 1:

[0006]

[0007] In formula 1, S is the solid content; m is the mass of the slurry sample to be tested; V is the volume of the slurry sample to be tested; ρ 1 is the density of the clear liquid in the slurry sample to be tested; ρ 2 is the density of the solid phase in the slurry sample to be tested.

[0008] As described above, the solid content test method of the ternary precursor slurry, the ρ 1 Calculated by the following method:

[0009] 1) The slurry sample to be tested is subjected to layering treatment to obtain a first clear liquid, wherein the volume of the first clear liquid is V 1 , V 1 Satisfy the requirements of equations 2 and 3;

[0010] 2) According to the density of the first clear liquid, obtain the p 1 ;

[0011] Where V = V 清 +V固 , Formula 2

[0012] V 1 <V 清 , Formula 3

[0013] V 清 is the total volume of the clear liquid in the slurry sample to be tested, V 固 is the total volume of the solid phase in the slurry sample to be tested.

[0014] As mentioned above, the solid content test method of the ternary precursor slurry, V 1 =(6%-16%)V 清 .

[0015] As mentioned above, the solid content test method of the ternary precursor slurry, V 1 =(3%-8%)V.

[0016] As described above, the solid content test method of the ternary precursor slurry, the ρ 2 Calculated by the following method:

[0017] 1) The slurry sample to be tested is subjected to layering treatment to obtain a first solid phase, wherein the volume of the first solid phase is V 2 , V 2 Satisfy the requirements of equations 2 and 4;

[0018] 2) According to the density of the first solid phase, obtain the p 2 ;

[0019] Where V = V 清 +V 固 , Formula 2

[0020] V 2 <V 固 , Formula 4

[0021] V 清 is the total volume of the clear liquid in the slurry sample to be tested, V 固 is the total volume of the solid phase in the slurry sample to be tested.

[0022] As mentioned above, the solid content test method of the ternary precursor slurry, V 2 =(10%-20%)V 固 .

[0023] As mentioned above, the solid content test method of the ternary precursor slurry, V 2 =(5%-10%)V.

[0024] The method for testing the solid content of the ternary precursor slurry as described above, before step 2), further comprises sequentially performing centrifugal cleaning treatment and drying treatment on the first solid phase.

[0025] In the test method for the solid content of the ternary precursor slurry as described above, the temperature of the drying treatment is 100-150°C.

[0026] In the test method for solid content of ternary precursor slurry as described above, V is 0.5-1.5L.

[0027] The present invention provides a method for testing the solid content of a ternary precursor slurry. The method obtains the solid content of the ternary precursor slurry by calculating through a formula with high accuracy. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The present invention provides a method for testing the solid content of a ternary precursor slurry. In some embodiments of the present invention, the solid content is calculated by formula 1:

[0030]

[0031] In formula 1, S is the solid content; m is the mass of the slurry sample to be tested; V is the volume of the slurry sample to be tested; ρ 1 is the density of the clear liquid in the slurry sample to be tested; ρ 2 is the density of the solid phase in the slurry sample to be tested.

[0032] It can be understood that when the mass m of the slurry sample to be tested, the volume V of the slurry sample to be tested, and the density ρ of the clear liquid in the slurry sample to be tested are obtained 1 And the density of the solid phase in the slurry sample to be tested ρ 2 When , it can be directly substituted into the above formula 1 to calculate the solid content S of the ternary precursor slurry.

[0033] The mass m of the slurry sample to be tested can be obtained by the following steps:

[0034] 1) Wash and dry the plastic sampling cup and rubber stopper, then weigh them to obtain the mass m 0 ;

[0035] 2) Take a certain amount of slurry from the reactor and put it into a plastic sampling cup, cover it with a rubber stopper, and weigh its mass m 1 ;

[0036] Therefore, the mass of the slurry sample to be tested is m=m1 -m 0 .

[0037] It can be understood that the reason for using plastic sampling cups and rubber stoppers for sampling is that alkali solution is used in the process of preparing the ternary precursor slurry, making the ternary precursor slurry alkaline, and using plastic sampling cups and rubber stoppers for sampling can avoid corrosion from the alkali solution.

[0038] Optionally, a pump may be used to measure the slurry from the reactor. Preferably, a peristaltic pump may be used to measure the slurry from the reactor.

[0039] Optionally, the above formula 1 for calculating the solid content of the ternary precursor slurry can be input into a computer, and when the mass m of the slurry sample to be tested, the volume V of the slurry sample to be tested, and the density ρ of the clear liquid in the slurry sample to be tested are obtained, 1 And the density of the solid phase in the slurry sample to be tested ρ 2 When the data is directly input into the computer, the solid content S of the ternary precursor slurry to be tested can be obtained.

[0040] In the embodiment of the present invention, the solid content S of the ternary precursor slurry to be tested is calculated by formula 1, which can reduce the influence of human factors on the test results and make the obtained solid content S more accurate.

[0041] In some embodiments of the present invention, 1 Calculated by the following method:

[0042] 1) The slurry sample to be tested is subjected to layering treatment to obtain a first clear liquid, the volume of which is V 1 , V 1 Satisfy the requirements of equations 2 and 3;

[0043] 2) According to the density of the first clear solution, obtain ρ 1 ;

[0044] Where V = V 清 +V 固 , Formula 2

[0045] V 1 <V 清 , Formula 3

[0046] V 清 is the total volume of the clear liquid in the slurry sample to be tested, V 固 is the total volume of the solid phase in the slurry sample to be tested.

[0047] It can be understood that the total volume V of the clear liquid in the slurry sample to be tested 清 The total solid volume V in the slurry sample to be tested 固 The sum is the volume V of the slurry sample to be tested, which satisfies Formula 2. Wherein, the volume V of the first clear liquid1 Less than the total volume V of the clear liquid in the slurry sample to be tested 清 , that is, equation 3 is satisfied. The density of the first clear liquid taken out is tested using a liquid density meter, and the density of the first clear liquid is ρ 1 .

[0048] In the embodiment of the present invention, the slurry sample to be tested is subjected to layering treatment to obtain a first clear liquid, and the density of the first clear liquid is tested to obtain the density of the clear liquid in the slurry sample to be tested. 1 Because it is not necessary to make the total volume of the slurry sample to be tested V 清 The total volume of the clear liquid and the slurry sample to be tested is V 固 The solid phase is completely separated, and only the total volume V 清 The density ρ of the clear liquid in the slurry sample to be tested can be obtained by taking part of the clear liquid (i.e., the first clear liquid) from the clear liquid. 1 Therefore, the testing method of the present invention can not only achieve high precision, but also has the advantage of fast testing speed.

[0049] In a specific embodiment, the first clear liquid is obtained by the following method: after taking out the slurry sample to be tested from the reactor, it is left to stand for a short time, such as 5 minutes, and the slurry sample to be tested is partially stratified. At this time, the uppermost layer can be considered as the clear liquid obtained by partial stratification. A portion of the supernatant is taken out to obtain the volume V of the first clear liquid. 1 .

[0050] When the above method is used to 1 When multiple tests (e.g., 20 or more) are performed, the density of the clear solution in each slurry sample to be tested is found to be 1 The error is within ±0.02. Therefore, in order to further improve the test efficiency without affecting the test accuracy, it is not necessary to test the density of the first clear liquid again. The density ρ of the clear liquid in the slurry sample to be tested obtained by multiple tests can be directly used. 1 The average value of ρ 1 Substitute it into formula 1 and calculate.

[0051] In some embodiments of the present invention, V 1 =(6%-16%)V 清 .

[0052] Optionally, when the volume V of the first clear solution is taken out 1 is 30-80 mL, preferably, the volume V of the first clear liquid taken out 1 is 50mL, the total volume of the clear liquid in the slurry sample to be tested is V 清 When the volume of the first clear liquid is 500 mL, calculate the volume V of the first clear liquid. 1 =(6%-16%)V 清That is, the volume of the first clear liquid taken out accounts for the total volume V of the clear liquid in the slurry sample to be tested. 清 When the density of the first clear liquid is 6%-16%, the density of the first clear liquid can be tested by a liquid density meter. At this time, the density of the first clear liquid obtained is the density of the clear liquid in the slurry sample to be tested. 1 .

[0053] In the embodiment of the present invention, the total volume V of the clear liquid in the slurry sample to be tested is taken out. 清 6%-16% of the first clear liquid, that is, the density of the clear liquid in the slurry sample to be tested can be obtained by testing the density of the first clear liquid 1 , making the test operation simple and convenient, and fast, saving time.

[0054] In some embodiments of the present invention, V 1 =(3%-8%)V.

[0055] Optionally, when the volume of the first clear solution V 1 The volume V of the slurry sample to be tested is 1000 mL, i.e. 1.0 L. The volume V of the first clear solution is calculated as 1 =(3%-8%) V. That is, when the volume of the first clear liquid taken out accounts for 3%-8% of the volume V of the slurry sample to be tested, the density of the first clear liquid can be tested by a liquid density meter to obtain the density ρ of the clear liquid in the slurry sample to be tested. 1 .

[0056] In the embodiment of the present invention, a small amount of the first clear liquid is taken out, that is, the volume V of the first clear liquid taken out is 1 The density of the clear liquid in the slurry sample to be tested can be obtained by measuring the density of the first clear liquid. 1 , making the test operation simple and convenient, and fast, saving time.

[0057] In some embodiments of the present invention, 2 Calculated by the following method:

[0058] 1) The slurry sample to be tested is subjected to layering treatment to obtain a first solid phase, the volume of which is V 2 , V 2 Satisfy the requirements of equations 2 and 4;

[0059] 2) According to the density of the first solid phase, obtain ρ 2 ;

[0060] Where V = V 清 +V 固 , Formula 2

[0061] V 2 <V固 , Formula 4

[0062] V 清 is the total volume of the clear liquid in the slurry sample to be tested, V 固 is the total volume of the solid phase in the slurry sample to be tested.

[0063] It can be understood that the total volume V of the clear liquid in the slurry sample to be tested 清 The total solid volume V in the slurry sample to be tested 固 The sum is the volume V of the slurry sample to be tested, which satisfies Formula 2. Among them, the volume V of the first solid phase 2 Less than the total solid volume V in the slurry sample to be tested 固 , which satisfies Formula 4. The density of the first solid phase taken out is tested using a solid density meter, and the density of the first solid phase is ρ 2 .

[0064] In the embodiment of the present invention, the slurry sample to be tested is subjected to layering treatment to obtain a first solid phase, and the density of the first solid phase is tested to obtain the density ρ of the solid phase in the slurry sample to be tested. 2 Because it is not necessary to make the total volume of the slurry sample to be tested V 清 The total volume of the clear liquid and the slurry sample to be tested is V 固 The solid phase is completely separated from the total volume V 固 The density ρ of the solid phase in the slurry sample to be tested can be obtained by taking part of the solid phase (i.e., the first solid phase) from the solid phase. 2 Therefore, the testing method of the present invention can not only achieve high precision, but also has the advantage of fast testing speed.

[0065] In a specific embodiment, the first solid phase is obtained by the following method: after taking out the slurry sample to be tested from the reactor, it is left to stand for a short time, such as 5 minutes, and the slurry sample to be tested is partially stratified. At this time, it can be considered that the bottom layer is partially stratified to obtain a solid phase. A small amount of the lower layer solid is taken out to obtain the volume V of the first solid phase. 2 .

[0066] When the above method is used to 2 When multiple tests (e.g., 20 or more times) are performed, the density of the solid phase in each slurry sample to be tested is found to be 2 The error is within ±0.02. Therefore, in order to further improve the test efficiency without affecting the test accuracy, there is no need to test the density of the first solid phase. The density ρ of the solid phase in the slurry sample to be tested obtained by multiple tests can be directly used. 2 The average value of ρ 2 Substitute it into formula 1 and calculate.

[0067] In some embodiments of the present invention, V2 =(10%-20%)V 固 .

[0068] Optionally, when the volume V of the first solid phase is removed 2 is 50-100 mL, preferably, the volume V of the first solid phase removed 1 is 80 mL, and the total solid volume V in the slurry sample to be tested 固 When the volume of the first solid phase is 500 mL, the volume V 2 =(10%-20%)V 固 That is, the volume of the first solid phase taken out accounts for the total volume V of the solid phase in the slurry sample to be tested. 固 When the density of the first solid phase is 10%-20%, the density of the first solid phase can be tested by a solid density meter. At this time, the density of the first solid phase obtained is the density of the solid phase in the slurry sample to be tested. 2 .

[0069] In the embodiment of the present invention, the total solid volume V of the slurry sample to be tested is taken out. 固 10%-20% of the solid phase, that is, the first solid phase, can be obtained by testing the density of the first solid phase to obtain the density of the solid phase in the slurry sample to be tested. 2 , making the test operation simple and convenient, and fast, saving time.

[0070] In some embodiments of the present invention, V 2 =(5%-10%)V.

[0071] Optionally, when the volume V of the first solid phase 2 The volume V of the slurry sample to be tested is 1000 mL, i.e. 1.0 L. The volume V of the first solid phase is calculated to be 2 =(5%-10%) V. That is, when the volume of the first solid phase taken out accounts for 5%-10% of the volume V of the slurry sample to be tested, the density of the first solid phase can be tested by a solid density meter to obtain the density ρ of the solid phase in the slurry sample to be tested. 2 .

[0072] In the embodiment of the present invention, a small amount of lower solid is taken out, that is, the volume V of the first solid phase taken out 2 The density of the solid phase in the slurry sample to be tested can be obtained by measuring the density of the first solid phase. 2 , making the test operation simple and convenient, and fast, saving time.

[0073] In some embodiments of the present invention, before step 2), the first solid phase is also subjected to centrifugal washing and drying treatments in sequence.

[0074] It can be understood that before performing a density test on a small amount of the first solid phase taken out after the stratification process, the first solid phase needs to be pre-treated, including centrifugal washing and drying.

[0075] The centrifugal washing process is used to remove impurities in the first solid phase. Specifically, deionized water is added to the first solid phase, centrifuged, and the supernatant is discarded. Repeat the washing process 2-3 times. It can be considered that the impurities in the first solid phase have been basically cleaned. Then the cleaned first solid phase is dried. Optionally, the first solid phase can be placed in a high-temperature oven for drying. Finally, the density of the first solid phase after drying can be tested using a solid density meter to obtain the density ρ of the solid phase in the slurry sample to be tested. 2 .

[0076] In the embodiment of the present invention, before the density test of the first solid phase is performed, a centrifugal cleaning process and a drying process are performed to remove impurities in the first solid phase, so that the density of the first solid phase obtained by the test, that is, the density of the solid phase in the slurry sample to be tested, is 2 The accuracy is higher, so the solid content S of the ternary precursor slurry calculated by substituting it into the formula later is more accurate. In addition, since the amount of the first solid phase used for centrifugal cleaning and drying is small, the time used is also shorter, which saves time cost for the overall solid content test.

[0077] In some embodiments of the present invention, the drying temperature is 100-150°C.

[0078] Optionally, after the first solid phase is centrifugally cleaned, a drying process is performed, and the drying process can be performed in a high-temperature oven, and the temperature of the oven can be set to 100-150° C. Preferably, the temperature of the oven can be set to 120° C. If the oven temperature is set too low, the drying process is not thorough and the use time is long; if the oven temperature is set too high, some substances in the solid phase will be decomposed, which will affect the accuracy of the test results.

[0079] The embodiment of the present invention can accelerate the drying speed of the solid phase by setting the drying temperature of the first solid phase to 100-150°C, saving time for the subsequent test of the density of the first solid phase and the final test of the solid content S of the ternary precursor slurry. In addition, the density of the first solid phase is more accurate after the drying process, thereby improving the accuracy of the solid content S of the ternary precursor slurry.

[0080] In some embodiments of the invention, V is 0.5-1.5L.

[0081] Optionally, the volume V of the slurry sample to be tested can be 0.5-1.5 L, preferably, 1.0 L. In the process of producing the ternary precursor slurry, it is necessary to sample the ternary precursor slurry to test the solid content. If too much sampling is taken, it will cause waste of raw materials, and too little sampling will cause the test results to be inaccurate. When the sampling amount is 0.5-1.5 L, it will not cause waste of raw materials and can also ensure the accuracy of the solid content test results.

[0082] The sampling amount V of the slurry sample to be tested in this embodiment is based on the small-scale and pilot stages in the synthesis process of the ternary precursor slurry. If the production volume is large or small, the sampling amount V of the slurry sample to be tested can be adjusted according to actual needs.

[0083] In this embodiment, by setting the volume V of the slurry sample to be tested to 0.5-1.5 L, the waste of raw materials is avoided while ensuring the accuracy of the test results.

[0084] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0085] Example 1

[0086] The test method of the solid content of the ternary precursor slurry of this embodiment includes the following steps:

[0087] 1) Wash and dry the plastic sampling cup and rubber stopper and weigh them. The mass is m. 0 =284g;

[0088] 2) 1.0L of ternary precursor slurry was taken from the reactor by a peristaltic pump, covered with a rubber stopper and weighed. The total mass was m 1 =1495g;

[0089] 3) After the ternary precursor slurry to be taken out is left to stand for 5 minutes, 50 mL of the first clear liquid is taken out and the density of the first clear liquid is tested by a liquid density meter. The density is ρ 1 =1.1242g / cm 3 ;

[0090] 4) Take a small amount of the first solid phase in the lower layer and centrifuge it for three times, dry the solid in an oven at 120°C, take 5g of the solid, and test the density of the dried solid using a solid density meter. The density is ρ 2 =3.7800g / cm 3 ;

[0091] 5) The solid content S of the ternary precursor slurry was calculated by the above formula 1, and the result was 114 g / L.

[0092] It takes about 1 hour to complete the above method.

[0093] Example 2-3

[0094] The method for testing the solid content of the ternary precursor slurry in Example 2-3 is the same as that in Example 1, except that the parameters are different. The specific parameters are shown in Table 1.

[0095] Comparative Example 1

[0096] The ternary precursor slurry of this comparative example is the same as that of Example 1.

[0097] The test method for the solid content of the ternary precursor slurry of this comparative example (i.e., the decantation method) includes the following steps:

[0098] 1) Clean and dry the plastic sampling cup and rubber stopper;

[0099] 2) Measure 1 L of ternary precursor slurry from the reactor using a peristaltic pump and cover it with a rubber stopper;

[0100] 3) The ternary precursor slurry to be taken out is allowed to stand for 1 hour to make the upper layer in the sampling cup clear, the supernatant is poured out, and it is washed with deionized water 2-3 times;

[0101] 4) Clean the drying tray and weigh its mass of 102 g, transfer all the cleaned slurry to the drying tray, and put it into a 120°C oven for drying;

[0102] 5) After drying (about 2 hours), cool to room temperature and weigh 225 g of the mixture, with a solid content of 123 g / L.

[0103] It takes about 6 hours to complete the above method.

[0104] Comparative Example 2

[0105] The ternary precursor slurry of this comparative example is the same as that of Example 2.

[0106] The method for testing the solid content of the ternary precursor slurry in this comparative example is basically the same as that in comparative example 1. The specific parameters are shown in Table 1.

[0107] Comparative Example 3

[0108] The ternary precursor slurry of this comparative example is the same as that of Example 3.

[0109] The method for testing the solid content of the ternary precursor slurry in this comparative example is basically the same as that in comparative example 1. The specific parameters are shown in Table 1.

[0110] Table 2 is a comparison table of solid content test data. The theoretical solid content in Table 2 is calculated based on the feed concentration and flow rate in the continuous production process, as well as the ratio between various substances.

[0111] Table 1

[0112]

[0113]

[0114] Table 2

[0115]

[0116] Combining Table 1 and Table 2, it can be seen that, compared with the comparative example, the test method for the solid content of the ternary precursor slurry provided by the present invention can reduce the influence of human factors on the test results, so that the obtained solid content S is more accurate.

[0117] The reason why the comparative ratio is not accurate is that when the decantation method is used to dry the slurry, the higher the solid content of the slurry, the longer the drying time required. Due to the limited area of ​​the drying tray and the restrictions of the cleaning conditions, when the solid content of the slurry is higher, the degree of drying is lower and the amount of impurities removed by cleaning is limited, so the final solid content deviation is greater.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for testing the solid content of a ternary precursor slurry, characterized in that, the solid content is calculated by Equation 1: In Formula 1, S is the solid content; m is the mass of the slurry sample to be measured; V is the volume of the slurry sample to be measured; ρ 1 is the density of the clear liquid in the slurry sample to be measured; ρ 2 is the density of the solid phase in the slurry sample to be measured.

2. The method for testing the solid content of a ternary precursor slurry according to claim 1, characterized in that, Said ρ 1 is calculated by the following method: 1) Perform a layering process on the slurry sample to be measured to obtain a first supernatant liquid, and the volume of the first supernatant liquid is V 1 , V 1 Meet the requirements of Equation 2 and Equation 3; 2) Obtain the ρ according to the density of the first supernatant liquid 1 ; where, V = V 清 + V 固 Equation 2 V 1 <V 清 Formula 3 V 清 is the total volume of the clear liquid in the slurry sample to be measured, V 固 is the total volume of the solid phase in the slurry sample to be measured.

3. The method for testing the solid content of a ternary precursor slurry according to claim 2, characterized in that, V 1 = (6% - 16%)V 清 .

4. The method for testing the solid content of a ternary precursor slurry according to claim 2 or 3, characterized in that, V 1 = (3% - 8%)V.

5. The method for testing the solid content of a ternary precursor slurry according to claim 1, characterized in that, The said ρ 2 is calculated by the following method: 1) Perform a layering process on the slurry sample to be measured to obtain a first solid phase, and the volume of the first solid phase is V 2 , V 2 Meet the requirements of Formula 2 and Formula 4; 2) Obtain the ρ according to the density of the first solid phase 2 ; where V = V 清 + V 固 Equation 2 V 2 <V 固 Formula 4 V 清 is the total volume of the clear liquid in the slurry sample to be measured, V 固 is the total volume of the solid phase in the slurry sample to be measured.

6. The method for testing the solid content of a ternary precursor slurry according to claim 5, characterized in that, V 2 = (10% - 20%)V 固 .

7. The method for testing the solid content of a ternary precursor slurry according to claim 5 or 6, characterized in that, V 2 = (5% - 10%)V.

8. The method for testing the solid content of a ternary precursor slurry according to any one of claims 5-7, characterized in that, before step 2), centrifugal cleaning treatment and drying treatment are also performed on the first solid phase in sequence.

9. The method for testing the solid content of a ternary precursor slurry according to claim 8, characterized in that, the temperature of the drying treatment is 100-150°C.

10. The method for testing the solid content of a ternary precursor slurry according to any one of claims 1-7, characterized in that, the V is 0.5-1.5 L.

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