Method and system for measuring content of secondary particles in graphite material, electronic equipment and storage medium

Abstract

The invention provides a method and system for determining the content of secondary particles in a graphite material, electronic equipment and a storage medium, and belongs to the technical field of secondary batteries. The determination method comprises the following steps: S1, obtaining powder pressure variables F of a plurality of groups of graphite material samples with different secondary particle contents H, and obtaining a powder pressure variable F of a graphite material to be measured; s2, constructing a corresponding relation between the secondary particle content H and the powder pressure variable F of the multiple groups of graphite material samples; s3, determining the content H of the secondary particles in the to-be-detected graphite material according to the powder pressure variable F of the to-be-detected graphite material and the corresponding relation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of secondary batteries, and particularly relates to a method for measuring the content of secondary particles in a graphite material, a measurement system, an electronic device and a storage medium. BACKGROUND

[0002] At present, artificial graphite is still the mainstream negative electrode material used in lithium ion batteries, and there are single-particle products, secondary-particle products and mixed products of single particles and secondary particles in artificial graphite related products. Under the same particle size distribution, the secondary-particle products have better rate performance, low-temperature performance and higher compaction density than the single-particle products. With the large-scale application of secondary particles and mixed products, it is particularly important to develop a method for measuring the content of secondary particles in a graphite material.

[0003] Patent application file CN119846001A discloses a detection method for the content of secondary particles in graphite. The detection method establishes a relationship model according to the correlation between the overall isotropy degree (OI value) of graphite and the content of secondary particles, and then determines the content of secondary particles in the target graphite according to the model. However, the detection method has low accuracy. In addition, the actual operation of the detection method is complex, and the accuracy of the XRD diffractometer is relied on, which is time-consuming and laborious for testing and data post-processing. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the related art to some extent. To this end, the embodiments of the present application propose a method for measuring the content of secondary particles in a graphite material, a measurement system, an electronic device and a storage medium.

[0005] In a first aspect, the embodiments of the present application provide a method for measuring the content of secondary particles in a graphite material, which comprises the following steps: S1. Obtain the powder compression variable F of a plurality of groups of graphite material samples with different secondary particle content H, and obtain the powder compression variable F of the graphite material to be measured; F = 100Q / Y; Q is the particle compressive strength of the graphite material, Q = (Xn+Xv) / 2; Xn is the change rate of the graphite material Dn10 after pressure, Xn = (ADn10 / Dn10A)*100%; ADn10 is the reduced number distribution value of the graphite material after pressure, ADn10 = Dn10A-Dn10B; Dn10A is the particle size corresponding to the number distribution percentage of 10% of the graphite material, Dn10B is the particle size corresponding to the number distribution percentage of 10% of the graphite material after pressure; Xv is the change rate of the graphite material Dv50 after pressure, Xv = (ADv50 / Dv50A)*100%; ADv50 is the reduced volume distribution value of the graphite material after pressure, ADv50 = Dv50A-Dv50B; Dv50A is the particle size corresponding to the volume distribution percentage of 50% of the graphite material, Dv50B is the particle size corresponding to the volume distribution percentage of 50% of the graphite material after pressure; Y is the order degree of the graphite material, Y is equal to the ratio of I G and I D ; S2. Constructing the corresponding relationship between the secondary particle content H and the powder compression variable F of a plurality of groups of the graphite material samples; S3. Determining the secondary particle content H in the graphite material to be measured according to the powder compression variable F of the graphite material to be measured and the corresponding relationship.

[0006] In some embodiments, the step S1 specifically comprises the following steps: S11. Providing a plurality of groups of the graphite material samples, each group of the graphite material samples having a different secondary particle content H; S12. Testing the powder compression variable F of a plurality of groups of the graphite material samples; S13. Storing the secondary particle content H and the corresponding powder compression variable F of a plurality of groups of the graphite material samples to form an F-H database.

[0007] In some embodiments, the step S11 specifically comprises the following steps: mixing single-particle graphite and secondary-particle graphite at different mixing ratios to obtain a plurality of groups of the graphite material samples, the mixing ratio being equal to the secondary particle content H in the graphite material sample.

[0008] In some embodiments, the step S12 specifically comprises the following steps: S121. Respectively performing number particle size distribution testing and volume particle size distribution testing on each group of the graphite material samples to obtain Dn10A and Dv50A of each group of the graphite material samples; S122. The same pressure is applied to each group of the graphite material samples with the same mass for the same time, and then the particle size distribution test and the volume particle size distribution test are respectively performed on each group of the graphite material samples after being pressed to obtain Dn10B and Dv50B of each group of the graphite material samples after being pressed; S123. Xn of each group of the graphite material samples is calculated according to Dn10A and Dn10B of each group of the graphite material samples, and Xv of each group of the graphite material samples is calculated according to Dv50A and Dv50B of each group of the graphite material samples; S124. Q of each group of the graphite material samples is calculated according to Xn and Xv of each group of the graphite material samples; S125. Raman spectrum test is respectively performed on each group of the graphite material samples to obtain the Raman spectrum of each group of the graphite material samples, and I G and I D are read from the Raman spectrum; S126. Y of each group of the graphite material samples is calculated according to I G and I D ; S127. F of each group of the graphite material samples is calculated according to Q and Y of each group of the graphite material samples.

[0009] Preferably, in step S122, the mass of each group of the graphite material samples is 1g-4g, and more preferably 2g-3g.

[0010] Preferably, in step S122, the pressure applied is 1 ton-5 tons, and the pressure holding time is 10 seconds-40 seconds; more preferably, the pressure applied is 2.5 tons-3.5 tons, and the pressure holding time is 20 seconds-30 seconds.

[0011] In some embodiments, step S2 specifically comprises the following steps: fitting the linear relationship between the secondary particle content H and the powder pressing variable F of a plurality of groups of the graphite material samples as the corresponding relationship.

[0012] Optionally, step S2 specifically comprises the following steps: taking the secondary particle content H of a plurality of groups of the graphite material samples as the horizontal coordinate, taking the powder pressing variable F of a plurality of groups of the graphite material samples as the vertical coordinate, and making an F-H linear relationship graph, and obtaining the linear relationship F=aH+b from the F-H linear relationship graph as the corresponding relationship, wherein a is the slope and b is the intercept.

[0013] Optionally, in step S2, the graphite material samples are at least 5 groups; preferably, the graphite material samples are 5 groups-12 groups.

[0014] Optionally, in step S2, the secondary particle content H of the plurality of groups of graphite material samples is 0-100%, preferably 10-100%.

[0015] Optionally, in step S2, the difference between the secondary particle content H of two groups of graphite material samples with adjacent secondary particle content H values is 8-20%.

[0016] Optionally, in step S2, the secondary particle content of the plurality of groups of graphite material samples is arranged in an arithmetic sequence.

[0017] In some embodiments, step S3 specifically comprises the following steps: inputting the powder compression variable F of the graphite material to be measured into the corresponding relationship, and outputting the secondary particle content H in the graphite material to be measured.

[0018] In a second aspect, the embodiments of the present application provide a system for measuring the secondary particle content of a graphite material, comprising: an acquisition module, configured to acquire the powder compression variable F of a plurality of groups of graphite material samples with different secondary particle content H, and acquire the powder compression variable F of a graphite material to be measured; wherein F=100Q / Y; Q is the particle compression strength of the graphite material, Q=(Xn+Xv) / 2; Xn is the change rate of the graphite material Dn10 after compression, Xn=(ΔDn10 / Dn10A)*100%; ΔDn10 is the reduced number distribution value of the graphite material after compression, ΔDn10=Dn10A-Dn10B; Dn10A is the particle size corresponding to the number distribution percentage of 10% of the graphite material, Dn10B is the particle size corresponding to the number distribution percentage of 10% of the graphite material after compression; Xv is the change rate of the graphite material Dv50 after compression, Xv=(ΔDv50 / Dv50A)*100%; ΔDv50 is the reduced volume distribution value of the graphite material after compression, ΔDv50=Dv50A-Dv50B; Dv50A is the particle size corresponding to the volume distribution percentage of 50% of the graphite material, Dv50B is the particle size corresponding to the volume distribution percentage of 50% of the graphite material after compression; Y is the order degree of the graphite material, Y is equal to the ratio of I G and I D in Raman spectrum; a construction module, configured to construct a corresponding relationship between the secondary particle content H and the powder compression variable F of the plurality of groups of graphite material samples; a determination module, configured to determine the secondary particle content H in the graphite material to be measured according to the powder compression variable F of the graphite material to be measured and the corresponding relationship.

[0019] In a third aspect, an electronic device is provided, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the determination method according to the first aspect when executing the computer program. In a fourth aspect, a computer readable storage medium is provided, which stores a computer program, and the computer program is executable on a processor to implement the steps of the determination method according to the first aspect.

[0020] Compared with the related art, the present application has the following advantages and technical effects: (1) The determination method of the present application introduces two testing methods of physical pressure test and Raman spectroscopy test, and performs mathematical analysis on the results to determine the powder compression variable F of the graphite material, F=100Q / Y. According to the correlation between the secondary particle content H and the powder compression variable F of multiple graphite material samples, a corresponding relationship is established, and then the secondary particle content H in the graphite material to be measured can be determined according to the corresponding relationship. Compared with the determination method in the related art, the determination method of the present application has higher accuracy, and in addition, the determination method of the present application is more simple and convenient, and can quickly obtain the secondary particle content in the graphite material to be measured, and has the advantages of time management. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 FIG. 1 is a F-H linear function relationship diagram obtained by the determination method of Example 1. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the terms "include" and "have" and any variations thereof used in the specification and claims of the present application and the above description of drawings are intended to cover the non-exclusive inclusion. In the description of the embodiments of the present application, the technical terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0024] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The occurrence of the phrase in various places in the specification is not necessarily all referring to the same embodiment, nor is it necessarily referring to a separate or alternative embodiment to the other embodiments. It is explicitly and implicitly contemplated that embodiments described herein can be combined with each other. The "range" disclosed in the present application is defined in the form of lower limit and upper limit, a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a particular range. The range defined in this way can include or not include the end value, and can be arbitrarily combined, i.e. any lower limit can be combined with any upper limit to form a range. For example, if the ranges of 60~120 and 80~110 are listed for a particular parameter, it is understood that the ranges of 60~110 and 80~120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4 and 5 are listed, the following ranges are all contemplated: 1~3, 1~4, 1~5, 2~3, 2~4 and 2~5. In the present application, unless otherwise specified, the numerical range "a~b" represents a shorthand representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0~5" means that all real numbers between "0~5" have been listed herein, and "0~5" is only a shorthand representation of these numerical combinations. In addition, when it is stated that a parameter is an integer ≥2, it is equivalent to disclose that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0025] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases of A alone, A and B together, and B alone.

[0026] In the description of the embodiments of the present application, the term "a plurality of" means two or more (including two), and similarly, "a plurality of groups" means two or more groups (including two groups), and "a plurality of pieces" means two or more pieces (including two pieces). In a first aspect, the embodiments of the present application provide a method for determining the content of secondary particles in a graphite material, the determination method comprising the following steps: S1. obtaining the powder compression variable F of a plurality of graphite material samples with different secondary particle contents H, and obtaining the powder compression variable F of the graphite material to be measured; Wherein, F=100Q / Y; Q is the particle compression strength of the graphite material, Q=(Xn+Xv) / 2; Xn is the change rate of the graphite material Dn10 after compression, Xn=(ADn10 / Dn10A)*100%; ADn10 is the reduced number distribution value of the graphite material after compression, ADn10=Dn10A-Dn10B; Dn10A is the particle size corresponding to the number distribution percentage of 10% of the graphite material, Dn10B is the particle size corresponding to the number distribution percentage of 10% of the graphite material after compression; Xv is the change rate of the graphite material Dv50 after compression, Xv=(ADv50 / Dv50A)*100%; ADv50 is the reduced volume distribution value of the graphite material after compression, ADv50=Dv50A-Dv50B; Dv50A is the particle size corresponding to the volume distribution percentage of 50% of the graphite material, Dv50B is the particle size corresponding to the volume distribution percentage of 50% of the graphite material after compression; Y is the order degree of the graphite material, Y is equal to the ratio of I G and I D ; S2. Constructing the corresponding relationship between the secondary particle content H and the powder compression variable F of a plurality of graphite material samples; S3. Determining the secondary particle content H in the graphite material to be measured according to the powder compression variable F of the graphite material to be measured and the corresponding relationship.

[0027] The applicant found that the secondary particle content H of a plurality of graphite material samples and the powder compression variable F (F=100Q / Y) of the graphite material were related and constructed to form a corresponding relationship, and the secondary particle content H in the graphite material to be measured could be determined according to the corresponding relationship. The specific analysis is as follows: The single particles in the graphite material are still single particles after low load, but the secondary particles are single particles bonded by granulation, and their strength is insufficient to support the applied pressure, so a part of the secondary particles will be broken into single particles and smaller secondary particles. In addition, it should be clear that in the determination method of the embodiments of the present application, the single particles contained in the graphite material to be measured and the plurality of graphite material samples are consistent, i.e. they are single particles prepared by the same raw material and the same preparation method; the secondary particles contained in the graphite material to be measured and the plurality of graphite material samples are also consistent, i.e. they are secondary particles prepared by the same raw material and the same preparation method, so the strength of the secondary particles in the same product is the same, and the damage degree under the same pressure is also the same, therefore the determination method of the embodiments of the present application can obtain the secondary particle content H in the graphite material through mathematical analysis of the particle compression strength Q of the graphite material.

[0028] The order degree Y of the graphite material refers to the degree of the graphite crystal structure close to perfect graphite. The G peak (about 1580 cm -1 ) in the Raman spectrum of a single particle is high and the D peak (about 1350 cm -1 ) is weak, and the I G / I D ratio is high, that is, the order degree Y is high; the D peak is significantly enhanced due to the increase of defects in the secondary particles, and the I G / I D ratio is low, that is, the order degree Y is low. Therefore, the determination method in the embodiments of the present application can obtain the secondary particle content H in the graphite material through mathematical analysis of the order degree Y of the graphite material.

[0029] The determination method in the embodiments of the present application introduces two testing methods of physical pressure testing and Raman spectroscopy testing, and performs mathematical analysis on the results, thereby determining the powder compression variable F of the graphite material, F = 100Q / Y. According to the correlation between the secondary particle content H and the powder compression variable F of a plurality of groups of graphite material samples, a corresponding relationship is established, and then the secondary particle content H in the graphite material to be tested can be determined according to the corresponding relationship. Compared with the determination method in the related art, the determination method in the embodiments of the present application has higher accuracy, and is more simple and convenient, and can quickly obtain the secondary particle content in the graphite material to be tested. The operation method and equipment are simple, and have time management advantages. It can be understood that the testing method in the embodiments of the present application is also applicable to the evaluation of the secondary particle content in other mixed materials.

[0030] In some embodiments, the step S1 specifically comprises the following steps: S11. providing a plurality of groups of graphite material samples, each group of graphite material samples having different secondary particle content H; S12. testing the powder compression variable F of the plurality of groups of graphite material samples; S13. storing the secondary particle content H and the corresponding powder compression variable F of the plurality of groups of graphite material samples to form an F-H database.

[0031] The determination method in the embodiments of the present application obtains the secondary particle content H of a plurality of groups of graphite material samples and the powder compression variable F under different secondary particle content H, and establishes the F-H database from the statistical point of view, which is beneficial to guiding the establishment of the corresponding relationship between F and H.

[0032] In some embodiments, step S11 specifically comprises the following steps: mixing single-particle graphite and secondary-particle graphite at different mixing ratios to obtain a plurality of groups of graphite material samples, wherein the mixing ratio is equal to the secondary-particle content H in the graphite material sample. That is, in the determination method of the embodiments of the present application, the secondary-particle content H of each group of graphite material samples selected is determined. In some embodiments, step S12 specifically comprises the following steps: S121. Perform number particle size distribution test and volume particle size distribution test on each group of graphite material samples respectively to obtain Dn10A and Dv50A of each group of graphite material samples; S122. Apply the same pressure to each group of graphite material samples with the same mass for the same time, and then perform particle size distribution test and volume particle size distribution test on each group of graphite material samples after pressure application respectively to obtain Dn10B and Dv50B of each group of graphite material samples after pressure application; S123. Calculate Xn of each group of graphite material samples according to Dn10A and Dn10B of each group of graphite material samples, and calculate Xv of each group of graphite material samples according to Dv50A and Dv50B of each group of graphite material samples; S124. Calculate Q of each group of graphite material samples according to Xn and Xv of each group of graphite material samples; S125. Perform Raman spectrum test on each group of graphite material samples respectively to obtain Raman spectrum of each group of graphite material samples, and read out I G and I D from the Raman spectrum; S126. Calculate Y of each group of graphite material samples according to I G and I D ; S127. Calculate F of each group of graphite material samples according to Q and Y of each group of graphite material samples.

[0033] Because the number particle size distribution test, volume particle size distribution test and Raman spectrum test before and after pressure application are involved, a group of graphite material samples is prepared for each type of graphite material sample in the embodiments of the present application, and each group of graphite material samples includes a plurality of identical graphite material samples for the foregoing tests.

[0034] Preferably, in step S122, the mass of each group of graphite material samples is 1g-4g, preferably 2g-3g.

[0035] Preferably, in step S122, the applied pressure is 1 ton to 5 tons, for example 1 ton, 2 tons, 2.5 tons, 3 tons, 3.5 tons, 4 tons, 4.5 tons, 5 tons, etc.; and the pressure holding time is 10 seconds to 40 seconds, for example 10 seconds, 12 seconds, 15 seconds, 18 seconds, 20 seconds, 22 seconds, 25 seconds, 28 seconds, 30 seconds, 35 seconds, 40 seconds, etc. More preferably, the applied pressure is 2.5 tons to 3.5 tons; and the pressure holding time is 20 seconds to 30 seconds. Under the foregoing low load, the single particles of the graphite material will not be broken, but a part of the secondary particles will be broken into single particles and smaller secondary particles. The secondary particles used in each group of graphite material samples are consistent, and the pressure applied to each group of graphite material samples is the same, and the degree of damage after pressure is also the same. Therefore, the determination method of the embodiment of the application can obtain the secondary particle content H in the graphite material by mathematical analysis of the particle compression strength Q of the graphite material.

[0036] In some embodiments, step S2 specifically comprises the following steps: fitting the linear relationship between the secondary particle content H and the powder compression variable F of a plurality of groups of graphite material samples as the corresponding relationship.

[0037] Alternatively, step S2 specifically comprises the following steps: taking the secondary particle content H of a plurality of groups of graphite material samples as the abscissa, and taking the powder compression variable F of a plurality of groups of graphite material samples as the ordinate, to draw an F-H linear relationship graph, and obtaining the linear relationship F=aH+b from the F-H linear relationship graph as the corresponding relationship, wherein a is the slope and b is the intercept.

[0038] Alternatively, in step S2, the graphite material samples are at least 5 groups; and preferably, the graphite material samples are 5 groups to 12 groups. At least 5 groups of graphite material samples are set, and the linear relationship between the secondary particle content H and the powder compression variable F is fitted as the corresponding relationship. When the data points participating in fitting the corresponding relationship are relatively more, it is beneficial to improve the accuracy of the corresponding relationship. Of course, the selected data points should not be too many, otherwise it will also increase the workload and reduce the work efficiency, and therefore 5 groups to 12 groups of graphite material samples are preferably set, and the linear relationship between the secondary particle content H and the powder compression variable F is fitted as the corresponding relationship.

[0039] Optionally, in step S2, the secondary particle content H of the plurality of groups of graphite material samples is 0-100%, for example 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, etc., and is preferably 10-100%. The secondary particle content H of the plurality of groups of graphite material samples is set to meet the above conditions, which is advantageous for establishing a corresponding relationship between the secondary particle content H and the powder pressing variable F in a wide range, so as to be applicable to more determination of the secondary particle content H in the graphite material to be measured. If the secondary particle content H of the plurality of groups of graphite material samples is concentrated in a certain local range, when the secondary particle content H in the graphite material to be measured exceeds the range, the test result obtained may not be accurate enough.

[0040] Optionally, in step S2, the difference between the secondary particle content H of two groups of graphite material samples adjacent in value is 8-20%, for example 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc. The secondary particle content H of each group of graphite material samples can be set at the above difference or any value between any two values, which is advantageous for the uniform distribution of the value points in the range of 0-100%, thereby improving the accuracy of the fitted corresponding relationship. In addition, the secondary particle content H of the plurality of groups of graphite material samples can be arranged in an arithmetic sequence, for example H=5%, 15%, 25%, 35%, 45%, 55%, 65%, 75%, 85%, 95%, etc., or in a non-arithmetic sequence, for example 5%, 15%, 27%, 42%, 58%, 76%, 87%, 100%, etc. Considering the convenience and uniformity of setting, the secondary particle content H of the plurality of groups of graphite material samples is preferably arranged in an arithmetic sequence.

[0041] In some embodiments, step S3 specifically comprises the following steps: inputting the powder pressing variable F of the graphite material to be measured into the corresponding relationship, and outputting the secondary particle content H in the graphite material to be measured.

[0042] The determination method of the embodiments of the present application establishes a corresponding relationship between the secondary particle content H and the corresponding powder pressing variable F of a plurality of groups of graphite samples, which directly links the secondary particle content H and the powder pressing variable F. Based on the corresponding relationship, when the powder pressing variable F of the graphite material to be measured is determined, it can be directly input into the corresponding relationship to obtain the secondary particle content H in the graphite material to be measured. Therefore, the determination method of the embodiments of the present application can directly quantitatively analyze the secondary particle content H in the graphite material.

[0043] Optionally, a F-H linear relationship graph is made with the secondary particle content H of the plurality of groups of graphite material samples as the horizontal coordinate and the powder pressing variable F of the plurality of groups of graphite material samples as the vertical coordinate, and a linear relationship F=aH+b is obtained from the F-H linear relationship graph, where a is the slope and b is the intercept. Based on this, after the powder pressing variable F of the graphite material to be measured is determined, it can be input into the linear relationship F=aH+b to directly calculate the secondary particle content H in the graphite material to be measured. It can be understood that the slope a and the intercept b are related to the preparation process of the secondary particles and the test parameters (such as the pressure applied, the pressure applied time, etc.) of the powder pressing variable F, so the slope a and the intercept b do not have fixed values and are not particularly limited here. As long as the consistency of the single particles and the secondary particles in the graphite material to be measured and the graphite material samples is maintained, and the test parameters of the powder pressing variable F of the graphite material to be measured and the test parameters of the powder pressing variable F of the graphite material samples are the same, the establishment of the linear relationship F=aH+b will not be affected, and the accuracy of the secondary particle content F of the graphite material to be measured obtained by the test will not be affected.

[0044] In a second aspect, the embodiments of the present application provide a system for measuring the secondary particle content of a graphite material, and the system comprises: an acquisition module, configured to acquire the powder pressing variable F of a plurality of groups of graphite material samples with different secondary particle content H, and acquire the powder pressing variable F of the graphite material to be measured; wherein F=100Q / Y; Q is the particle compressive strength of the graphite material, Q=(Xn+Xv) / 2; Xn is the change rate of the graphite material Dn10 after pressure is applied, Xn=(ΔDn10 / Dn10A)*100%; ΔDn10 is the reduced number distribution value of the graphite material after pressure is applied, ΔDn10=Dn10A-Dn10B; Dn10A is the particle size corresponding to the number distribution percentage of 10% of the graphite material, and Dn10B is the particle size corresponding to the number distribution percentage of 10% of the graphite material after pressure is applied; Xv is the change rate of the graphite material Dv50 after pressure is applied, Xv=(ΔDv50 / Dv50A)*100%; ΔDv50 is the reduced volume distribution value of the graphite material after pressure is applied, ΔDv50=Dv50A-Dv50B; Dv50A is the particle size corresponding to the volume distribution percentage of 50% of the graphite material, and Dv50B is the particle size corresponding to the volume distribution percentage of 50% of the graphite material after pressure is applied; Y is the order degree of the graphite material, Y is equal to the ratio of I G and I D in the Raman spectrum; a construction module, configured to construct the corresponding relationship between the secondary particle content H and the powder pressing variable F of the plurality of groups of graphite material samples; A determination module is configured to determine the secondary particle content H in the graphite material to be tested according to the powder compression variable F of the graphite material to be tested and the corresponding relationship. The implementation scheme of the test system provided by the embodiments of the present application for solving the problem is similar to the implementation scheme described in the test method of the first aspect, and therefore the specific limitations of the test system can be referred to the limitations of the determination method described above, which will not be repeated here.

[0045] In a third aspect, the embodiments of the present application provide an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the determination method of the first aspect when executing the computer program. In a fourth aspect, the embodiments of the present application provide a computer readable storage medium, which stores a computer program, and the computer program implements the steps of the determination method of the first aspect when executed by a processor.

[0046] The present application will be described in detail below with reference to the embodiments and the accompanying drawings.

[0047] Single-particle artificial graphite and secondary-particle artificial graphite are provided, and a preparation method of the single-particle artificial graphite and the secondary-particle artificial graphite is as follows: (1) Oil-based needle coke (Shandong Jingyang Technology Co., Ltd.) is crushed into coke blocks with a diameter of less than 2 cm, and is dried at 105°C for 180 min.

[0048] (2) The dried material obtained in step (1) is put into a mechanical mill for grinding, and the particle length-diameter ratio of the ground material is controlled to be less than 1.5, and the ground material is then subjected to a shaping treatment.

[0049] (3) A part of the shaped material obtained in step (2) is sent into a box furnace for pre-carbonization, and the pre-carbonization temperature rising curve is as follows: 60 min for rising to 300°C, 150 min for rising to 550°C, 100 min for keeping at 550°C, 100 min for rising to 700°C, 100 min for rising to 900°C, 40 min for rising to 1000°C, 120 min for keeping at 1000°C, and then the material is discharged after cooling to room temperature.

[0050] (4) Another part of the shaped material obtained in step (2) is added to 205℃ softening point pitch (Liaoning Xinxin New Material Technology Co., Ltd.) equivalent to 9% of the mass of the material for granulation. The granulation temperature curve is as follows: 25℃ for 30min and the rotation speed is controlled at 100r / min, 90min to 300℃ and the rotation speed is controlled at 60r / min, 60min to 500℃ and the rotation speed is controlled at 80r / min, 500℃ for 120min and the rotation speed is controlled at 100r / min, 90min to 650℃ and the rotation speed is controlled at 100r / min, 60min to 750℃ and the rotation speed is controlled at 100r / min, 750℃ for 180min and the rotation speed is controlled at 90r / min, cooling to room temperature and discharging, and the rotation speed is 90r / min during the cooling process.

[0051] (5) The granulated material obtained in step (4) is shaped to a suitable particle size using a shaper and a fusion machine.

[0052] (6) The shaped material obtained in step (5) is sent into a box furnace for pre-carbonization. The pre-carbonization temperature curve is as follows: 60min to 300℃, 150min to 550℃, 550℃ for 100min, 100min to 700℃, 100min to 900℃, 20min to 950℃, 950℃ for 120min, cooling to room temperature and discharging.

[0053] (7) The pre-carbonized material obtained in step (3) and the pre-carbonized material obtained in step (6) are respectively graphitized by a medium frequency furnace. The graphitization temperature is 2800~3200℃, and the highest temperature is maintained for 140min.

[0054] (8) The single-particle artificial graphite is obtained by using the graphitized material obtained in step (3) after graphitization, mixing for 30min at 550r / min, 325 mesh screening, and removing magnetic field. The single-particle artificial graphite is a micron-level powder. The single-particle artificial graphite is entirely composed of single particles.

[0055] The pre-carbonized material obtained in step (6) is graphitized to obtain a graphitized material, which is subjected to mixing at 550 r / min for 30 min, 325 mesh screening, and magnetic removal to obtain secondary particle artificial graphite. The secondary particle artificial graphite is a micron-level powder. The secondary particle artificial graphite is basically secondary particles and may contain a small amount of single particles, but the content of secondary particles in a product of secondary particle artificial graphite cannot be 100%, which is an ideal state. Therefore, it can be understood that the content of secondary particles in the secondary particle artificial graphite can be approximately considered to be 100%. Moreover, the content of secondary particles in the secondary particle artificial graphite prepared by the same process is consistent, and the secondary particle artificial graphite produced by the same process and the same batch is used in subsequent Examples 1-11 for determination, which does not affect the accuracy of the determination results.

[0056] Example 1 Step 1. The single particle artificial graphite and the secondary particle artificial graphite obtained above are mixed at different mixing ratios to obtain a plurality of groups of graphite materials. The mixing ratio is based on the content H of secondary particles in the graphite material, and the mixing ratio is 0, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%, respectively, a total of 11 groups of samples, each group of samples including multiple portions. The above 11 groups of samples are denoted as P0, P 10 , P 20 , P 30 , P 40 , P 50 , P 60 , P 70 , P 80 , P 90 , and P 100 .

[0057] Step 2. An appropriate amount of samples P0, P 10 , P 20 , P 30 , P 40 , P 50 , P 60 , P 70 , P 80 , P 90 , and P 100 obtained in step 1 are taken, an appropriate amount of dispersant is added, and after being fully mixed, an appropriate amount of deionized water is added, ultrasonic dispersion is performed until uniform, and particle size detection is performed in a particle size instrument sample pool to obtain Dn10A and Dv50A of each group of samples. The specific data are shown in Table 1.

[0058] Step 3. 2 g of samples P0, P 10 , P 20 , P 30 , P 40 , P50 P 60 P 70 P 80 P 90 P 100 Place the sample into a specially designed stamping die, and then place the stamping die into a powder compaction tester (manufacturer: Wuxi Qirui Technology Co., Ltd., model: PCD2000). The powder compaction tester applies a pressure of 3 tons to the sample in the stamping die and holds the pressure for 20 seconds. Then, the pressure is released, and the sample is taken out after the pressure is applied.

[0059] Step 4. Take appropriate amounts of the pressurized samples P0 and P obtained in Step 3, respectively. 10 P 20 P 30 P 40 P 50 P 60 P 70 P 80 P 90 P 100 Add the sample to a beaker, add an appropriate amount of dispersant, mix thoroughly, add an appropriate amount of deionized water, and ultrasonically disperse evenly. Then, put the sample into the sample cell of a particle size analyzer (manufacturer: Malvern Instruments Ltd., UK, model: Mastersizer3000) for particle size detection, export the volume distribution and quantity distribution data, and obtain the Dn10B and Dv50B of each group of samples after pressure application, as shown in Table 1.

[0060] Step 5. Calculate Xn for each group of samples based on Dn10A and Dv50A, Xn = (ΔDn10 / Dn10A) * 100%, ΔDn10 = Dn10A - Dn10B; the specific Xn results are shown in Table 2.

[0061] Based on the Dn10B and Dv50B of each group of samples after pressure application, the Xv of each group of samples after pressure application was calculated as follows: Xv = (ΔDv50 / Dv50A) * 100%, ΔDv50 = Dv50A - Dv50B; the specific Xv results are shown in Table 2. Based on Xn and Xv of each group of samples, the particle compressive strength Q=(Xn+Xv) / 2 of each group of samples is calculated, as shown in Table 2. Step 6. Take appropriate amounts of samples P0 and P obtained in Step 1 respectively. 10 P 20 P 30 P 40 P 50 P 60 P 70 P 80 P 90 P 100Raman spectrum selected area face scanning was performed, the selected area was 200 μm*200 μm, the step length was 5 μm, three regions were selected, a total of 600 points were selected, the Raman spectrum of each sample was obtained, I G and I D were read from the Raman spectrum, the peak intensity ratio I G / I D was calculated, and after arranging in ascending order and removing the top 10% and bottom 10% data values, the average value was obtained, thereby obtaining the order degree Y of each group of samples, as shown in Table 2.

[0062] Step 7. According to Q and Y of each group of samples, the powder compression variable F of each group of samples was calculated, F = 100Q / Y, and the F results are shown in Table 2.

[0063] Step 8. The samples P 10 , P 20 , P 30 , P 40 , P 50 , P 60 , P 70 , P 80 , P 90 , P 100 were taken as graphite material samples, the secondary particle content H of the samples P 10 , P 20 , P 30 , P 40 , P 50 , P 60 , P 70 , P 80 , P 90 , P 100 was taken as the abscissa, and the corresponding powder compression variable F was taken as the ordinate, a function relationship was fitted and established, and the secondary particle content H and the powder compression variable F were in a linear function relationship F = 2.75H-11.6 (as shown in Table 2). Figure 1

[0064] Step 9. Taking sample P0 as the graphite material to be measured, the powder compression variable F of sample P0 measured in step 7 was brought into the linear function relationship F = 2.75H-11.6 of step 8, and the secondary particle content H of sample P0 was calculated to be 4.38%.

[0065] The calculated value 4.38% of the secondary particle content H of sample P0 was compared with the actual value 0, and the error was +4.38%.

[0066] Example 2 The determination method of this example was the same as that of Example 1, and the difference was that: Step 8. The samples P0, P 20 , P 30 , P 40 ​、P 50 、P 60 、P 70 、P 80 、P 90 、P 100 As the graphite material sample, the secondary particle content H of the sample P0, P 20 、P 30 、P 40 、P 50 、P 60 、P 70 、P 80 、P 90 、P 100 is taken as the abscissa, and the corresponding powder pressing variable F is taken as the ordinate, a function relationship is fitted and established, and the secondary particle content H and the powder pressing variable F conform to a linear function relationship F = 2.75H - 11.6.

[0067] Step 9. Taking the sample P 10 as the graphite material to be tested, the powder pressing variable F of the sample P 10 measured in step 7 is brought into the linear function relationship F = 2.75H - 11.6 of step 8, and the secondary particle content H of the sample P 10 is calculated to be 11.89%.

[0068] The calculated value 11.89% of the secondary particle content H of the sample P 10 compared with the actual value 10% has an error of +1.89%.

[0069] Example 3 The determination method of this example is the same as that of example 1, and the difference lies in that: Step 8. The samples P0, P 10 , P 30 , P 40 , P 50 , P 60 , P 70 , P 80 , P 90 , P 100 are taken as the graphite material sample, the secondary particle content H of the sample P0, P 10 , P 30 , P 40 , P 50 , P 60 , P 70 , P 80 , P 90 , P 100 is taken as the abscissa, and the corresponding powder pressing variable F is taken as the ordinate, a function relationship is fitted and established, and the secondary particle content H and the powder pressing variable F conform to a linear function relationship F = 2.75H - 11.6.

[0070] Step 9. Take sample P 20 as the graphite material to be measured, and bring the powder compression variable F of sample P 20 measured in step 7 into the linear function relationship F = 2.75H - 11.6 in step 8 to calculate the secondary particle content H of sample P 20 as 19.76%.

[0071] The calculated value 19.76% of the secondary particle content H of sample P 20 compared with the actual value 20% has an error of -0.24%.

[0072] Example 4 The determination method of this example is the same as that of example 1, except that: Step 8. Take samples P0, P 10 , P 20 , P 40 , P 50 , P 60 , P 70 , P 80 , P 90 , P 100 as graphite material samples, and take the secondary particle content H of samples P0, P 10 , P 20 , P 40 , P 50 , P 60 , P 70 , P 80 , P 90 , P 100 as the abscissa and take the corresponding powder compression variable F as the ordinate to fit and establish a function relationship, and the secondary particle content H and the powder compression variable F conform to a linear function relationship F = 2.75H - 11.6.

[0073] Step 9. Take sample P 30 as the graphite material to be measured, and bring the powder compression variable F of sample P 30 measured in step 7 into the linear function relationship F = 2.75H - 11.6 in step 8 to calculate the secondary particle content H of sample P 30 as 26.82%.

[0074] The calculated value 26.82% of the secondary particle content H of sample P 30 compared with the actual value 30% has an error of -3.18%.

[0075] Example 5 The determination method of this example is the same as that of example 1, except that: Step 8. Take samples P0, P 10 , P 20 , P30 50 60 70 80 90 100 As the graphite material sample, the secondary particle content H of the samples P0, P 10 20 30 50 60 70 80 90 100 The secondary particle content H of the sample P 40 is taken as the abscissa, and the corresponding powder pressing variable F is taken as the ordinate, a function relationship is established by fitting, and the secondary particle content H and the powder pressing variable F conform to a linear function relationship F = 2.75H - 11.6.

[0076] Step 9. Taking the sample P 40 as the graphite material to be tested, the powder pressing variable F of the sample P 40 measured in step 7 is brought into the linear function relationship F = 2.75H - 11.6 in step 8, and the secondary particle content H of the sample P 40 is calculated to be 37.19%.

[0077] The calculated value 37.19% of the secondary particle content H of the sample P 40 compared with the actual value 40% has an error of -2.81%.

[0078] Example 6 The determination method of this example is the same as that of example 1, and the difference lies in that: Step 8. The samples P0, P 10 , P 20 , P 30 , P 40 , P 60 , P 70 , P 80 , P 90 , P 100 As the graphite material sample, the secondary particle content H of the samples P0, P 10 , P 20 , P 30 , P 40 , P 60 , P 70 , P 80 , P 90 , P 100 The secondary particle content H of the sample P 40 is taken as the abscissa, and the corresponding powder pressing variable F is taken as the ordinate, a function relationship is established by fitting, and the secondary particle content H and the powder pressing variable F conform to a linear function relationship F = 2.75H - 11.6.​​​​​​​​​​

[0079] Step 9. Take sample P 50 as the graphite material to be measured, and bring the powder compression variable F of sample P 50 measured in step 7 into the linear function relationship F = 2.75H - 11.6 in step 8 to calculate the secondary particle content H of sample P 50 as 48.21%.

[0080] The calculated value 48.21% of the secondary particle content H of sample P 50 compared with the actual value 50% has an error of -1.79%.

[0081] Example 7 The determination method of this example is the same as that of example 1, except that: Step 8. Take samples P0, P 10 , P 20 , P 30 , P 40 , P 50 , P 70 , P 80 , P 90 , P 100 as graphite material samples, and take the secondary particle content H of samples P0, P 10 , P 20 , P 30 , P 40 , P 50 , P 70 , P 80 , P 90 , P 100 as the abscissa and take the corresponding powder compression variable F as the ordinate to fit and establish a function relationship, and the secondary particle content H and the powder compression variable F conform to a linear function relationship F = 2.75H - 11.6.

[0082] Step 9. Take sample P 60 as the graphite material to be measured, and bring the powder compression variable F of sample P 60 measured in step 7 into the linear function relationship F = 2.75H - 11.6 in step 8 to calculate the secondary particle content H of sample P 60 as 59.48%.

[0083] The calculated value 59.48% of the secondary particle content H of sample P 60 compared with the actual value 60% has an error of -0.52%.

[0084] Example 8 The determination method of this example is the same as that of example 1, except that: Step 8. Take samples P0, P 10 , P20 、P 30 、P 40 、P 50 、P 60 、P 80 、P 90 、P 100 As a graphite material sample, the secondary particle content H of samples P0, P 10 、P 20 、P 30 、P 40 、P 50 、P 60 、P 80 、P 90 、P 100 The secondary particle content H is the abscissa, and the corresponding powder pressing variable F is the ordinate. The function relationship is fitted and established. The secondary particle content H and the powder pressing variable F conform to the linear function relationship F = 2.75H - 11.6.

[0085] Step 9. Taking sample P 70 as the graphite material to be tested, the powder pressing variable F of sample P 70 measured in step 7 is brought into the linear function relationship F = 2.75H - 11.6 in step 8, and the secondary particle content H of sample P 70 is calculated to be 68.57%.

[0086] The calculated value of the secondary particle content H of sample P 70 is 68.57%, and the error compared with the actual value 70% is -1.43%.

[0087] Example 9 The determination method of this example is the same as that of example 1, and the difference is that: Step 8. Samples P0, P 10 , P 20 , P 30 , P 40 , P 50 , P 60 , P 70 , P 90 , P 100 As a graphite material sample, the secondary particle content H of samples P0, P 10 , P 20 , P 30 , P 40 , P 50 , P 60 , P 70 , P 90 , P 100Using the secondary particle content H as the abscissa and the corresponding powder compression variable F as the ordinate, a functional relationship is established by fitting. The secondary particle content H and the powder compression variable F conform to a linear functional relationship F=2.75H-11.6.

[0088] Step 9. Using sample P 80 For the graphite material to be tested, the sample P obtained in step 7 is used. 80 Substituting the powder pressing variable F into the linear function relationship F=2.75H-11.6 from step 8, the sample P is calculated. 80 The secondary particle content (H) is 77.59%.

[0089] Sample P 80 The calculated value of secondary particle content H, 77.59%, has an error of -2.41% compared to the actual value of 80%.

[0090] Example 10 The measurement method in this embodiment is the same as that in Example 1, except that: Step 8. Place samples P0 and P... 10 P 20 P 30 P 40 P 50 P 60 P 70 P 80 P 100 As a graphite material sample, with sample P0 and P 10 P 20 P 30 P 40 P 50 P 60 P 70 P 80 P 100 Using the secondary particle content H as the abscissa and the corresponding powder compression variable F as the ordinate, a functional relationship is established by fitting. The secondary particle content H and the powder compression variable F conform to a linear functional relationship F=2.75H-11.6.

[0091] Step 9. Using sample P 90 For the graphite material to be tested, the sample P obtained in step 7 is used. 90 Substituting the powder pressing variable F into the linear function relationship F=2.75H-11.6 from step 8, the sample P is calculated. 90 The secondary particle content (H) is 90.84%.

[0092] Sample P 90 The calculated value of secondary particle content H, 90.84%, is 0.84% ​​lower than the actual value of 90%.

[0093] Example 11 The measurement method in this embodiment is the same as that in Example 1, except that: Step 8. Place samples P0 and P... 10 P 20 P 30 P 40 P 50 P 60 P 70 P 80 P 90 As a graphite material sample, with sample P0 and P 10 P 20 P 30 P 40 P 50 P 60 P 70 P 80 P 90 Using the secondary particle content H as the abscissa and the corresponding powder compression variable F as the ordinate, a functional relationship is established by fitting. The secondary particle content H and the powder compression variable F conform to a linear functional relationship F=2.75H-11.6.

[0094] Step 9. Using sample P 100 For the graphite material to be tested, the sample P obtained in step 7 is used. 100 Substituting the powder pressing variable F into the linear function relationship F=2.75H-11.6 from step 8, the sample P is calculated. 100 The content of secondary particles H in the middle is 101.81%.

[0095] Sample P 100 The calculated value of secondary particle content H, 101.81%, has an error of +1.81% compared to the actual value of 100%.

[0096] Table 1. Samples P0~P 100 physical parameters

[0097] Table 2. Samples P0~P 100 physical parameters

[0098] Table 3. Content of secondary particles in graphite materials and its error as determined by the methods used in Examples 1-11

[0099] The error is equal to the measured value of the secondary particle content H in the graphite material minus the actual value of H. As shown in Table 3, the determination methods in Examples 1-11 yielded smaller errors in the secondary particle content H, indicating higher testing accuracy. Therefore, to determine the blending ratio of secondary particles in the graphite material to be tested, it is only necessary to measure the powder compression variable F of the graphite material. Then, by substituting the powder compression variable F into the fitted linear function relationship, the secondary particle content H in the graphite material can be obtained.

[0100] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0101] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for measuring the content of secondary particles in a graphite material, characterized by, The determination method comprises the following steps: S1. Obtain the powder compression variable F of a plurality of groups of graphite material samples with different secondary particle contents H, and obtain the powder compression variable F of the graphite material to be measured; Wherein, F=100Q / Y; Q is the particle compressive strength of the graphite material, Q=(Xn+Xv) / 2; Xn is the change rate of the graphite material Dn10 after pressure, Xn=(ADn10 / Dn10A)*100%; ADn10 is the reduced number distribution value of the graphite material after pressure, ADn10=Dn10A-Dn10B; Dn10A is the particle size corresponding to the number distribution percentage of the graphite material reaching 10%, Dn10B is the particle size corresponding to the number distribution percentage of the graphite material reaching 10% after pressure; Xv is the change rate of the graphite material Dv50 after pressure, Xv=(ADv50 / Dv50A)*100%; ADv50 is the reduced volume distribution value of the graphite material after pressure, ADv50=Dv50A-Dv50B; Dv50A is the particle size corresponding to the volume distribution percentage of the graphite material reaching 50%, Dv50B is the particle size corresponding to the volume distribution percentage of the graphite material reaching 50% after pressure; Y is the order degree of the graphite material, Y is equal to the ratio of I G and I D in Raman spectrum. S2. Construct a corresponding relationship between the secondary particle content H and the powder compression variable F of the plurality of groups of graphite material samples; S3. Determine the secondary particle content H of the graphite material to be measured according to the powder compression variable F of the graphite material to be measured and the corresponding relationship.

2. The assay method according to claim 1, characterized by The step S1 specifically comprises the following steps: S11. Provide a plurality of groups of graphite material samples, each group of graphite material samples having a different secondary particle content H; S12. Test the powder compression variable F of the plurality of groups of graphite material samples; S13. Store the secondary particle content H and the corresponding powder compression variable F of the plurality of groups of graphite material samples to form an F-H database.

3. The assay method according to claim 2, characterized in that, Step S11 specifically comprises the following steps: mixing single-particle graphite and secondary-particle graphite at different mixing ratios to obtain a plurality of groups of graphite material samples, the mixing ratio being equal to the secondary particle content H in the graphite material sample.

4. The assay method according to claim 2, characterized by Step S12 specifically comprises the following steps: S121. Perform number particle size distribution testing and volume particle size distribution testing on each group of graphite material samples respectively to obtain Dn10A and Dv50A of each group of graphite material samples; S122. Apply the same pressure to each group of graphite material samples with the same mass for the same holding time, and then perform particle size distribution testing and volume particle size distribution testing on each group of graphite material samples after pressure application respectively to obtain Dn10B and Dv50B of each group of graphite material samples after pressure application; S123. Calculate Xn of each group of graphite material samples according to Dn10A and Dn10B of each group of graphite material samples, and calculate Xv of each group of graphite material samples according to Dv50A and Dv50B of each group of graphite material samples; S124. Calculate Q of each group of graphite material samples according to Xn and Xv of each group of graphite material samples; S125. Respectively, the graphite material sample of each group is subjected to Raman spectrum test, and Raman spectrum of the graphite material sample of each group is obtained; I G with I D ; S126. Y of each group of the graphite material samples is calculated according to I G With I D , Y of each group of the graphite material samples is calculated. S127. Calculate F of each group of graphite material samples according to Q and Y of each group of graphite material samples; Preferably, in step S122, the mass of each group of graphite material samples is 1g-4g, more preferably 2g-3g; Preferably, in step S122, the applied pressure is 1 ton-5 tons and the holding time is 10 seconds-40 seconds; more preferably, the applied pressure is 2.5 tons-3.5 tons and the holding time is 20 seconds-30 seconds.

5. The assay method according to claim 1, characterized by, Step S2 specifically comprises the following steps: fitting a linear relationship between the secondary particle content H and the powder compression variable F of the plurality of groups of graphite material samples as the corresponding relationship; Alternatively, step S2 specifically comprises the following steps: taking the secondary particle content H of the plurality of groups of graphite material samples as the horizontal coordinate and the powder compression variable F of the plurality of groups of graphite material samples as the vertical coordinate to draw an F-H linear relationship graph, and obtaining a linear relationship F=aH+b from the F-H linear relationship graph as the corresponding relationship, wherein a is the slope and b is the intercept.

6. The assay method according to claim 5, characterized in that, In step S2, the graphite material samples are at least 5 groups; preferably, the graphite material samples are 5-12 groups; Optionally, in step S2, the secondary particle content H of the plurality of groups of graphite material samples is 0-100%, preferably 10-100%; Optionally, in step S2, the difference between the secondary particle content H of the two groups of graphite material samples adjacent in value is 8-20%; Optionally, in step S2, the secondary particle content of the plurality of groups of graphite material samples is arranged in an arithmetic sequence.

7. The assay method according to claim 1, characterized by, Step S3 specifically comprises the following steps: inputting the powder compression variable F of the graphite material to be measured into the corresponding relationship, and outputting the secondary particle content H in the graphite material to be measured.

8. A system for measuring the content of secondary particles in a graphite material, characterized by The determination system comprises: an acquisition module, configured to acquire the powder compression variable F of a plurality of groups of graphite material samples with different secondary particle content H, and acquire the powder compression variable F of the graphite material to be measured; Wherein, F=100Q / Y; Q is the particle compressive strength of the graphite material, Q=(Xn+Xv) / 2; Xn is the change rate of the graphite material Dn10 after pressure, Xn=(ADn10 / Dn10A)*100%; ADn10 is the reduced number distribution value of the graphite material after pressure, ADn10=Dn10A-Dn10B; Dn10A is the particle size corresponding to the number distribution percentage of the graphite material reaching 10%, Dn10B is the particle size corresponding to the number distribution percentage of the graphite material reaching 10% after pressure; Xv is the change rate of the graphite material Dv50 after pressure, Xv=(ADv50 / Dv50A)*100%; ADv50 is the reduced volume distribution value of the graphite material after pressure, ADv50=Dv50A-Dv50B; Dv50A is the particle size corresponding to the volume distribution percentage of the graphite material reaching 50%, Dv50B is the particle size corresponding to the volume distribution percentage of the graphite material reaching 50% after pressure; Y is the order degree of the graphite material, Y is equal to the ratio of I G and I D in Raman spectrum. a construction module, configured to construct a corresponding relationship between the secondary particle content H and the powder compression variable F of the plurality of groups of graphite material samples; a determination module, configured to determine the secondary particle content H in the graphite material to be measured according to the powder compression variable F of the graphite material to be measured and the corresponding relationship.

9. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the computer program to realize the steps of the determination method according to any one of claims 1-7.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to realize the steps of the determination method according to any one of claims 1-7.

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