Battery short-circuit resistance calculation method, system and storage medium

Abstract

The present application relates to a method, system and storage medium for calculating the short-circuit resistance of a battery. The method obtains the foreign particle size of the corresponding magnetic metal foreign matter; based on a preset resistance and foreign matter size model, the foreign particle size is processed to obtain the short-circuit resistance of the battery to be tested, thereby achieving accurate calculation of the battery short-circuit resistance based on the foreign particle size of the magnetic metal foreign matter, and establishing a correlation between the foreign particle size of the magnetic metal foreign matter and the short-circuit resistance of the battery, so as to quantitatively attribute the internal short circuit of the battery, reduce the quantitative analysis error of the positive pole magnetic metal foreign matter particle size and the battery short-circuit resistance, improve the accuracy of calculating the battery short-circuit resistance, and avoid causing a poor battery k value.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method, system and storage medium for calculating short-circuit resistance of a battery. Background Art

[0002] The battery is mainly composed of positive electrode parts, negative electrode parts, diaphragms and electrolytes. The positive electrode parts are usually made of metal oxides. During the battery production process, impurities or external contamination are easily generated on the positive electrode parts, resulting in the generation of positive magnetic metal foreign matter such as copper and zinc on the positive electrode parts. The positive magnetic metal foreign matter is electrolyzed into ions in the high potential area of ​​the positive electrode, passes through the diaphragm, and is reduced and deposited as metal precipitates in the low potential area of ​​the negative electrode. In addition to being deposited on the metal surface, this metal precipitate is also deposited in the pores of the diaphragm, causing black spots on the diaphragm, which in turn triggers a short circuit in the battery, resulting in a poor battery k value (k value represents the voltage drop of the battery per unit time).

[0003] At present, there is limited research on the relationship between the particle size of positive magnetic metal foreign matter and the short-circuit resistance of the battery. The existing method for calculating the short-circuit resistance of the battery has low accuracy, and the quantitative analysis of the particle size of positive magnetic metal foreign matter and the short-circuit resistance of the battery has large errors. Summary of the invention

[0004] Based on this, a method, system and storage medium for calculating short-circuit resistance of a battery are provided.

[0005] In a first aspect, the present application provides a method for calculating a short-circuit resistance of a battery, comprising the following steps:

[0006] Obtain the foreign matter particle size corresponding to the magnetic metal foreign matter;

[0007] Based on the preset resistance and foreign matter size model, the foreign matter particle size is processed to obtain the short-circuit resistance of the battery to be tested.

[0008] In one embodiment, the step of processing the foreign matter particle size based on the preset resistance and foreign matter size model to obtain the short-circuit resistance of the battery to be tested includes:

[0009] Acquire diaphragm detection data corresponding to the diaphragm, black spot detection data corresponding to the black spot, and foreign matter feature data corresponding to the magnetic metal foreign matter;

[0010] According to the foreign matter characteristic data, diaphragm detection data and black spot detection data, a preset resistance and foreign matter size model is established.

[0011] In one embodiment, the membrane detection data includes the membrane thickness and the membrane area, the black spot detection data includes the black spot density and the black spot conductivity, and the foreign matter characteristic data includes the foreign matter density, the number of foreign matters and the foreign matter electrolysis coefficient;

[0012] The steps of establishing a preset resistance and foreign body size model according to foreign body feature data, diaphragm detection data and black spot detection data include:

[0013] Perform mass calculation on the diaphragm thickness, black spot density, foreign matter density, foreign matter quantity and foreign matter electrolysis coefficient to obtain a preset size model;

[0014] Conductivity calculation processing is performed on the diaphragm area, black spot conductivity, and the preset size model to obtain a preset conductivity model;

[0015] According to the preset size model and the preset conductivity model, a preset resistance and foreign matter size model is obtained.

[0016] In one embodiment, the step of performing mass calculation processing on the diaphragm thickness, black spot density, foreign matter density, foreign matter quantity and foreign matter electrolysis coefficient to obtain a preset size model includes:

[0017] Obtaining a preset foreign matter precipitation amount; the preset foreign matter precipitation amount is the foreign matter precipitation amount between the positive electrode member and the diaphragm and / or between the negative electrode member and the diaphragm;

[0018] The spot quality is obtained according to the black spot size, the thickness and the density of the black spots of the membrane to be tested;

[0019] The mass of metallic foreign matter exposed from the diaphragm and not corroded is obtained based on the foreign matter particle size, foreign matter density, foreign matter quantity and foreign matter electrolysis coefficient;

[0020] A preset size model is obtained based on the amount of foreign matter precipitation, the quality of spots and the quality of metal foreign matter.

[0021] In one embodiment, the diaphragm area includes the corroded diaphragm area and the uncorroded diaphragm area; the diaphragm resistance is obtained by connecting the resistance of the corroded diaphragm and the resistance of the uncorroded diaphragm in parallel; the corroded diaphragm does not completely isolate the uncorroded diaphragm, so that the resistance of the corroded diaphragm and the resistance of the uncorroded diaphragm are in an equivalent parallel state;

[0022] The steps of performing conductivity calculation processing on the diaphragm area, the black spot conductivity, and the preset size model to obtain the preset conductivity model include:

[0023] The diaphragm resistance is obtained according to the conductivity of the diaphragm to be measured, the diaphragm thickness and the diaphragm area;

[0024] The resistance of the corroded diaphragm is obtained according to the black spot conductivity, diaphragm thickness and corroded diaphragm area;

[0025] The uncorroded diaphragm resistance is obtained according to the uncorroded diaphragm conductivity to be measured, the diaphragm thickness and the uncorroded diaphragm area;

[0026] A preset conductivity model is obtained according to the diaphragm resistance, the corroded diaphragm resistance and the uncorroded diaphragm resistance.

[0027] In one embodiment, the preset size model is established by the following formula:

[0028]

[0029] Among them, R dr is the size of the black spot on the diaphragm to be tested, k is the electrolysis coefficient of foreign matter, r is the size of foreign matter particles, ρ m is the density of foreign matter, c is the preset amount of foreign matter precipitation, ρ dr is the density of black spots, h is the thickness of the diaphragm, and n is the number of foreign matter.

[0030] In one embodiment, the preset conductivity model is established by the following formula:

[0031]

[0032] Among them, σ s is the conductivity of the diaphragm to be measured, A is the diaphragm area, σ dr is the black spot conductivity, R dr is the size of the black spot on the diaphragm to be tested.

[0033] In one embodiment, the preset resistance and foreign body size model is established by the following formula:

[0034]

[0035] Among them, R ISCr is the short-circuit resistance, ρ dr is the density of black spots, σ dr is the black spot conductivity, h is the diaphragm thickness, r is the foreign particle size, ρ m is the foreign matter density, c is the preset foreign matter precipitation amount, k is the foreign matter electrolysis coefficient, and n is the number of foreign matter.

[0036] In one embodiment, based on the preset resistance and the foreign matter size model, the foreign matter particle size is processed to obtain the short-circuit resistance of the battery to be tested, and then the step includes:

[0037] According to the short-circuit resistance, the preset internal resistance and voltage drop mapping relationship is queried to obtain the voltage drop data of the corresponding battery to be tested.

[0038] In a second aspect, the present application provides a battery short-circuit resistance calculation system, including a processing device and a battery to be tested, wherein the processing device is connected to the battery to be tested;

[0039] The processing device is used to execute the steps of any one of the above-mentioned methods for calculating the short-circuit resistance of a battery.

[0040] In a third aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of any of the above-mentioned methods for calculating the short-circuit resistance of a battery are implemented.

[0041] One of the above technical solutions has the following advantages and beneficial effects:

[0042] In the above-mentioned method for calculating the short-circuit resistance of the battery, the foreign particle size corresponding to the magnetic metal foreign matter is obtained; based on the preset resistance and the foreign matter size model, the foreign particle size is processed to obtain the short-circuit resistance of the battery to be tested, thereby realizing the accurate calculation of the battery short-circuit resistance based on the foreign particle size of the magnetic metal foreign matter. This application establishes a correlation between the foreign particle size of the magnetic metal foreign matter and the short-circuit resistance of the battery based on the preset resistance and foreign matter particle size corresponding to the short-circuit resistance and the foreign matter particle size, and processes the preset resistance and foreign matter size model by the foreign matter particle size input, and then calculates the short-circuit resistance of the battery, so as to quantitatively attribute the internal short circuit of the battery, reduce the quantitative analysis error of the positive pole magnetic metal foreign matter particle size and the battery short-circuit resistance, improve the accuracy of calculating the battery short-circuit resistance, and avoid causing a poor battery k value. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A schematic diagram of an application scenario of a method for calculating short-circuit resistance of a battery in an embodiment of the present application;

[0044] Figure 2 This is a schematic diagram of a first flow chart of a method for calculating short-circuit resistance of a battery in an embodiment of the present application;

[0045] Figure 3 A second flow chart of the method for calculating the short-circuit resistance of a battery in an embodiment of the present application;

[0046] Figure 4 A schematic flow chart of the steps of establishing a preset resistance and foreign body size model in an embodiment of the present application;

[0047] Figure 5 A schematic diagram of the process of establishing a preset size model in an embodiment of the present application;

[0048] Figure 6 A schematic diagram of the process of establishing a preset conductivity model in an embodiment of the present application;

[0049] Figure 7 A third flow chart of the method for calculating the short-circuit resistance of a battery in an embodiment of the present application;

[0050] Figure 8 This is a schematic diagram of the structure of the magnetic metal foreign body before corrosion in the embodiment of the present application;

[0051] Fig. 9 This is a schematic diagram of the structure of the magnetic metal foreign body during corrosion in the embodiment of the present application;

[0052] Fig.10 This is a schematic diagram of the structure of the magnetic metal foreign body after corrosion in the embodiment of the present application;

[0053] Fig.11 Schematic diagram of the structure of the battery short-circuit resistance calculation system in the embodiment of the present application. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0055] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0056] In addition, the term "plurality" shall mean two or more.

[0057] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0058] The battery short-circuit resistance calculation method provided in this application can be applied to Figure 1In the application environment shown. Among them, the processing device may include a processor 102 and a memory 104, and the memory 104 may be used to store data such as preset resistance and foreign body size model, foreign body characteristic data, diaphragm detection data, black spot detection data, foreign body particle size and short-circuit resistance. The processor 102 can be used to obtain the foreign body particle size corresponding to the magnetic metal foreign body; based on the preset resistance and foreign body size model, the foreign body particle size is processed to obtain the short-circuit resistance of the battery to be tested. The processing device may also include a display 106, which may display the preset resistance and foreign body size model, foreign body characteristic data, diaphragm detection data, black spot detection data, foreign body particle size and short-circuit resistance through a graphical interface. Exemplarily, the processing device may be a BMS (battery management system), and the battery to be tested may be, but is not limited to, a winding or stacked battery.

[0059] In one embodiment, Figure 2 As shown, a method for calculating the short-circuit resistance of a battery is provided. Figure 1 The processor 102 in the embodiment is taken as an example to illustrate, and the following steps are included:

[0060] Step S210, obtaining the foreign matter particle size corresponding to the magnetic metal foreign matter.

[0061] Among them, the battery to be tested includes a positive electrode, a diaphragm and a negative electrode. The positive electrode is easily contaminated by external factors or generates positive magnetic metal foreign matter due to external factors. The diaphragm is arranged between the positive electrode and the negative electrode to avoid short circuit caused by contact between the positive electrode and the negative electrode. The diaphragm can be, but is not limited to, a polyolefin porous membrane. Black spots refer to spots formed by corrosion of positive magnetic metal foreign matter at the corresponding position of the diaphragm. For example, positive magnetic metal foreign matter is electrolyzed into ions in the high potential area of ​​the positive electrode, passes through the diaphragm, and is reduced and deposited as metal precipitates in the low potential area of ​​the negative electrode, and is deposited in the pores of the diaphragm, thereby generating black spots on the diaphragm. Magnetic metal foreign matter refers to positive magnetic metal foreign matter on the positive electrode, for example, magnetic metal foreign matter can be, but is not limited to, copper, zinc and iron. The foreign matter particle size can be measured for the magnetic metal foreign matter. For example, if the magnetic metal foreign matter is approximately spherical, the foreign matter particle size can be the radius of the magnetic metal foreign matter.

[0062] Exemplarily, the size of the magnetic metal foreign matter is measured to obtain the foreign matter particle size corresponding to the magnetic metal foreign matter.

[0063] Step S220 , based on the preset resistance and foreign matter size model, the foreign matter particle size is processed to obtain the short-circuit resistance of the battery to be tested.

[0064] The battery to be tested may be a regular shape structure such as a square or a circle, and it should be noted that the single cell may also be an irregular shape structure. The battery to be tested may be a lithium-ion cell, for example, a lithium iron phosphate cell, a ternary cell or a manganese iron lithium cell.

[0065] By inputting the foreign matter particle size into the preset resistance and foreign matter size model for processing, the short-circuit resistance of the corresponding battery to be tested is obtained, and then the performance of the battery to be tested is determined according to the size of the short-circuit resistance, so as to accurately control the positive magnetic metal foreign matter of the positive electrode and avoid poor battery k value. It should be noted that the smaller the short-circuit resistance, the worse the battery performance; the larger the short-circuit resistance, the better the battery performance. The battery k value refers to the voltage drop of the battery per unit time.

[0066] In the above-mentioned embodiment, by obtaining the foreign particle size corresponding to the magnetic metal foreign matter; based on the preset resistance and the foreign matter size model, the foreign particle size is processed to obtain the short-circuit resistance of the battery to be tested, and the accurate calculation of the battery short-circuit resistance based on the foreign particle size of the magnetic metal foreign matter is realized. The present application is based on the preset resistance and foreign matter size model corresponding to the short-circuit resistance and the foreign matter particle size, that is, the association between the foreign particle size of the magnetic metal foreign matter and the short-circuit resistance of the battery is established, and the preset resistance and foreign matter size model are input through the foreign matter particle size for processing, and then the battery short-circuit resistance is calculated to quantitatively attribute the internal short circuit of the battery, reduce the quantitative analysis error of the positive magnetic metal foreign matter particle size and the battery short-circuit resistance, improve the accuracy of calculating the battery short-circuit resistance, and avoid causing a poor battery k value.

[0067] In one embodiment, Figure 3 As shown, a method for calculating the short-circuit resistance of a battery is provided. Figure 1 The processor 102 in the embodiment is taken as an example to illustrate, and the following steps are included:

[0068] Step S310, obtaining the foreign matter particle size corresponding to the magnetic metal foreign matter.

[0069] For the specific description of the above step S310, please refer to the description of the above embodiment, which will not be repeated here.

[0070] Step S320, acquiring the diaphragm detection data corresponding to the diaphragm, the black spot detection data corresponding to the black spot, and the foreign matter feature data corresponding to the magnetic metal foreign matter.

[0071] Among them, the diaphragm detection data refers to the diaphragm characteristic data that can be obtained by detecting the diaphragm. For example, the size of the diaphragm can be detected to obtain the thickness and area of ​​the corresponding diaphragm. The black spot detection data refers to the black spot characteristic data that can be obtained by detecting the black spots. For example, the density of the black spots can be detected to obtain the density of the corresponding black spots. The foreign body characteristic data refers to the characteristic data obtained by detecting magnetic metal foreign matter. For example, the density of the magnetic metal foreign matter can be detected to obtain the density of the corresponding magnetic metal foreign matter. For another example, the foreign body characteristic data can also be the electrolysis coefficient of the corresponding magnetic metal foreign matter.

[0072] Exemplarily, by performing feature detection on the diaphragm, diaphragm detection data is obtained, by performing feature detection on black spots on the diaphragm, black spot detection data corresponding to the black spots is obtained, and by performing feature detection on magnetic metal foreign matter, foreign matter feature data corresponding to the magnetic metal foreign matter is obtained.

[0073] Step S330 , establishing a preset resistance and foreign matter size model according to the foreign matter feature data, the diaphragm detection data and the black spot detection data.

[0074] Among them, the preset resistance and foreign body size model can be used to represent the relationship between the short-circuit resistance of the battery and the size of the magnetic metal foreign body. The preset resistance and foreign body size model can be established through historical test data. For example, based on the calculation formula of internal resistance: R = h / (σ*A), where R is the internal resistance, h is the thickness of the diaphragm, A is the diaphragm area, and σ is the conductivity of the diaphragm, the historical test data can be processed to establish the preset resistance and foreign body size model.

[0075] Step S340 , based on the preset resistance and foreign matter size model, the foreign matter particle size is processed to obtain the short-circuit resistance of the battery to be tested.

[0076] For the specific description of the above step S340, please refer to the description of the above embodiment, which will not be repeated here.

[0077] In the above-mentioned embodiment, by establishing a preset resistance and a foreign matter size model corresponding to the short-circuit resistance and the foreign matter particle size, and then establishing a correlation between the foreign matter particle size of the magnetic metal foreign matter and the battery short-circuit resistance, the preset resistance and the foreign matter size model are input through the foreign matter particle size for processing, and then the battery short-circuit resistance is calculated, so as to quantitatively attribute the internal short circuit of the battery, reduce the quantitative analysis error of the positive pole magnetic metal foreign matter particle size and the battery short-circuit resistance, improve the accuracy of calculating the battery short-circuit resistance, and avoid causing a poor battery k value.

[0078] In one embodiment, the diaphragm detection data includes diaphragm thickness and diaphragm area, the black spot detection data includes black spot density and black spot conductivity, and the foreign matter characteristic data includes foreign matter density, foreign matter quantity and foreign matter electrolysis coefficient.

[0079] like Figure 4 As shown, the steps of establishing a preset resistance and foreign body size model according to foreign body feature data, diaphragm detection data and black spot detection data include:

[0080] Step S410, performing mass calculation processing on the diaphragm thickness, black spot density, foreign matter density, foreign matter quantity and foreign matter electrolysis coefficient to obtain a preset size model.

[0081] Among them, the diaphragm is a sheet structure, and the thickness of the diaphragm can be obtained by measurement. The density of black spots can be obtained by measuring the mass and volume of the corresponding black spots, and then calculating the corresponding black spot density based on the mass and volume of the black spots. The density of foreign matter can be determined according to the material of the magnetic metal foreign matter. The foreign matter density corresponding to magnetic metal foreign matter of different materials is different. For example, the material of the metal foreign matter can be obtained, and the corresponding foreign matter density can be obtained by querying the mapping relationship table between density and material.

[0082] The number of foreign matter can be referred to as the number of positive magnetic metal foreign matter on the diaphragm. The foreign matter electrolysis coefficient is used to indicate the electrolysis difficulty coefficient of positive magnetic metal foreign matter. For example, if the positive magnetic metal foreign matter is copper particles, copper particles are easier to be electrolyzed at the positive electrode, then the value of the foreign matter electrolysis coefficient is larger; if the positive magnetic metal foreign matter is zinc particles, zinc particles are more difficult to be electrolyzed at the positive electrode, then the value of the foreign matter electrolysis coefficient is smaller, that is, the foreign matter electrolysis coefficient corresponding to copper particles is greater than the foreign matter electrolysis coefficient corresponding to zinc particles.

[0083] Based on the mass calculation formula of the positive magnetic metal foreign matter, the thickness of the diaphragm, the black spot density, the foreign matter density, the number of foreign matters and the foreign matter electrolysis coefficient are mass calculated and processed to obtain a preset size model. It should be noted that the preset size model can be used to represent the relationship between the size of the black spot on the diaphragm and the size of the positive magnetic metal foreign matter. Preferably, the preset size model can be used to represent the relationship between the radius of the black spot on the diaphragm and the radius of the positive magnetic metal foreign matter.

[0084] Step S420, performing conductivity calculation processing on the diaphragm area, the black spot conductivity, and the preset size model to obtain a preset conductivity model.

[0085] The area of ​​the diaphragm can be obtained by measurement; for example, if the diaphragm is rectangular, the length and width of the diaphragm can be measured, and then the area of ​​the diaphragm can be obtained according to the length and width of the diaphragm. The conductivity of the black spot can be obtained by detection; for example, the conductivity of the black spot can be measured by a conductivity tester, and then the corresponding conductivity of the black spot can be obtained.

[0086] Based on the resistance calculation formula of the corroded part and the uncorroded part on the diaphragm, the conductivity calculation processing is performed on the diaphragm area, the black spot conductivity, and the preset size model, and then the preset conductivity model is obtained. It should be noted that the preset conductivity model can be used to represent the relationship between the diaphragm conductivity and the black spot conductivity.

[0087] Step S430, obtaining a preset resistance and foreign matter size model according to the preset size model and the preset conductivity model.

[0088] The preset size model and the preset conductivity model are introduced into the calculation formula of the internal resistance (R=h / (σ*A)), and then the preset resistance and foreign matter size model are obtained, and then the relationship between the foreign matter particle size of the magnetic metal foreign matter and the battery short-circuit resistance is established, so as to quantitatively attribute the internal short circuit of the battery and reduce the quantitative analysis error of the positive magnetic metal foreign matter particle size and the battery short-circuit resistance; the preset resistance and the foreign matter size model are input by the foreign matter particle size for processing, and then the battery short-circuit resistance is calculated, which improves the accuracy of calculating the battery short-circuit resistance and avoids causing poor battery k value.

[0089] In one embodiment, Figure 5 As shown, the steps of performing mass calculation processing on the diaphragm thickness, black spot density, foreign matter density, foreign matter quantity and foreign matter electrolysis coefficient to obtain a preset size model include:

[0090] Step S510, obtaining a preset foreign matter precipitation amount; the preset foreign matter precipitation amount is the foreign matter precipitation amount between the positive electrode member and the diaphragm and / or between the negative electrode member and the diaphragm.

[0091] The preset foreign matter precipitation amount refers to the mass of the sediment deposited between the diaphragm and the positive electrode member and / or between the diaphragm and the negative electrode member after the positive magnetic metal foreign matter is electrolyzed.

[0092] Exemplarily, based on the fact that the amount of foreign matter deposited between the separator and the positive electrode member and / or between the separator and the negative electrode member is smaller than the total amount of positive magnetic metal foreign matter, the preset foreign matter deposition amount may be set to a constant.

[0093] Step S520, obtaining the spot quality according to the black spot size, the membrane thickness and the black spot density of the membrane to be tested.

[0094] Among them, the spot mass refers to the mass of foreign matter deposited on the diaphragm black spots after the positive magnetic metal foreign matter is decomposed. The diaphragm black spot size to be measured refers to the size of the deposited foreign matter on the black spots or the diaphragm black spots. For example, if the deposited foreign matter on the black spots is cylindrical and covers the diaphragm black spots, then the diaphragm black spots are circular, that is, the diaphragm black spot size to be measured can be the radius of the diaphragm black spots. The black spot density refers to the density of the precipitated foreign matter on the diaphragm black spots. For example, if the precipitated foreign matter on the diaphragm black spots is in the shape of dendrite spots, then the black spot density is the dendrite spot density.

[0095] For example, Figure 8 As shown in the figure, the positive magnetic metal foreign matter is spherical in shape. As the positive magnetic metal foreign matter is electrolyzed (such as Fig. 9 As shown), at least part of the positive magnetic metal foreign matter will decompose and deposit between the separator and the positive electrode member and / or the negative electrode member (as shown in FIG. Fig.10 As shown in the figure, the diaphragm under the positive magnetic metal foreign matter is fully corroded, forming precipitation, so that part of the positive magnetic metal foreign matter will decompose and deposit on the black spots (as shown in the figure). Fig.10 As shown in Figure 2 ). The shape of the deposited foreign matter on the black spot is equivalent to a cylinder. Then, according to the quality formula based on the cylinder, the black spot size, membrane thickness and black spot density of the diaphragm to be tested are processed to obtain the spot quality.

[0096] Step S530, obtaining the mass of the metallic foreign matter protruding from the diaphragm and corroded according to the foreign matter particle size, foreign matter density, foreign matter quantity and foreign matter electrolysis coefficient.

[0097] The mass of metallic foreign matter refers to the mass of the part of the positive magnetic metallic foreign matter between the positive electrode and the diaphragm that protrudes from the diaphragm and is corroded. The density of foreign matter refers to the density of the positive magnetic metallic foreign matter. The number of foreign matter refers to the number of positive magnetic metallic foreign matter on the diaphragm.

[0098] For example, Fig.10 As shown, by testing the battery to be tested, the part that is not corroded and protrudes from the diaphragm can be in the shape of a cone, and the mass of the part that is corroded and protrudes from the diaphragm can be equivalent to the mass of a quarter of a sphere, that is, the mass of the cone-shaped part is also equivalent to the mass of a quarter of a sphere, and then according to the mass formula based on the sphere, the foreign matter particle size, foreign matter density, foreign matter quantity and foreign matter electrolysis coefficient are processed to obtain the mass of the metal foreign matter that protrudes from the diaphragm and is corroded.

[0099] Step S540, obtaining a preset size model according to the amount of foreign matter precipitation, the mass of spots and the mass of metal foreign matter.

[0100] like Fig.10 As shown, after the positive magnetic metal foreign matter protrudes and the diaphragm is decomposed and corroded, precipitated foreign matter is generated between the diaphragm and the positive and / or negative electrode parts, and dendrite spots are generated on the black spots of the diaphragm, and the mass of the metal foreign matter is equal to the foreign matter precipitation amount of the corresponding precipitated foreign matter and the spot mass of the corresponding dendrite spot. By modeling the foreign matter precipitation amount, spot mass and metal foreign matter mass, a preset size model is obtained.

[0101] In one embodiment, the preset size model is established by the following formula:

[0102]

[0103] Among them, R dr is the size of the black spot on the diaphragm to be tested, k is the electrolysis coefficient of foreign matter, r is the size of foreign matter particles, ρ m is the density of foreign matter, c is the preset amount of foreign matter precipitation, ρ dr is the density of black spots, h is the thickness of the diaphragm, and n is the number of foreign matter.

[0104] For example, through experimental testing, the positive magnetic metal foreign matter is approximately a sphere, then the foreign matter particle size can be the radius of the sphere; the dendrite spots on the diaphragm are approximately a cylinder, then the size of the diaphragm black spots to be tested can be the radius of the diaphragm black spots; the preset foreign matter precipitation amount can be a constant.

[0105] Based on the formula of the above-mentioned preset size model, the relationship between the size of the black spots on the diaphragm and the size of the positive magnetic metal foreign matter is established, which facilitates the attribution of the relationship between the particle size of the positive magnetic metal foreign matter and the size of the black spots on the diaphragm, and reduces the quantitative analysis error of the particle size of the positive magnetic metal foreign matter and the size of the black spots on the diaphragm.

[0106] In one embodiment, the diaphragm area includes the corroded diaphragm area and the uncorroded diaphragm area; the resistance of the diaphragm is obtained by connecting the resistance of the corroded diaphragm and the resistance of the uncorroded diaphragm in parallel; the corroded diaphragm does not completely isolate the uncorroded diaphragm, so that the resistance of the corroded diaphragm and the resistance of the uncorroded diaphragm are in an equivalent parallel state;.

[0107] Among them, the diaphragm can be divided into a corroded part and an uncorroded part, and the diaphragm area refers to the area of ​​the entire diaphragm, that is, the diaphragm area can be composed of the corroded diaphragm area and the uncorroded diaphragm area. The corroded part is within the uncorroded part, that is, the corroded diaphragm does not completely separate the uncorroded diaphragm, for example, the corroded diaphragm does not completely separate the uncorroded diaphragm horizontally or vertically, so that the resistance of the corroded diaphragm and the resistance of the uncorroded diaphragm are in an equivalent parallel state, that is, the resistance of the corroded diaphragm and the resistance of the uncorroded diaphragm are equivalent to resistances in parallel, and the resistance value of the diaphragm is equal to the value of the resistance of the corroded diaphragm and the resistance of the uncorroded diaphragm in parallel. It should be noted that the resistance of the uncorroded diaphragm is infinite.

[0108] like Figure 6 As shown, the steps of performing conductivity calculation processing on the diaphragm area, the black spot conductivity, and the preset size model to obtain the preset conductivity model include:

[0109] Step S610, obtaining the membrane resistance according to the measured membrane conductivity, membrane thickness and membrane area.

[0110] Among them, the diaphragm resistance refers to the resistance value of the entire diaphragm.

[0111] Based on the calculation formula of resistance, the conductivity of the diaphragm to be measured is multiplied by the diaphragm area to obtain first intermediate data, and the first intermediate data is divided by the diaphragm thickness to obtain the diaphragm resistance.

[0112] Step S620, obtaining the resistance of the corroded diaphragm according to the black spot conductivity, the diaphragm thickness and the corroded diaphragm area.

[0113] The corroded diaphragm resistance refers to the resistance value of the corroded part of the diaphragm.

[0114] Based on the calculation formula of resistance, the conductivity of black spots and the area of ​​the corroded diaphragm are multiplied to obtain the second intermediate data, and the second intermediate data is divided by the thickness of the diaphragm to obtain the resistance of the corroded diaphragm.

[0115] Step S630, obtaining the uncorroded membrane resistance according to the uncorroded membrane conductivity, membrane thickness and uncorroded membrane area to be measured.

[0116] The uncorroded diaphragm resistance refers to the resistance value of the uncorroded part of the diaphragm.

[0117] Based on the calculation formula of resistance, the conductivity of the uncorroded diaphragm to be measured is multiplied by the area of ​​the uncorroded diaphragm to obtain the third intermediate data, and the third intermediate data is divided by the diaphragm thickness to obtain the uncorroded diaphragm resistance.

[0118] Step S640, obtaining a preset conductivity model according to the diaphragm resistance, the corroded diaphragm resistance and the uncorroded diaphragm resistance.

[0119] Based on the resistor parallel formula, the value of the diaphragm resistance is equal to the value of the corroded diaphragm resistance and the uncorroded diaphragm resistance in parallel. By modeling the diaphragm resistance, the corroded diaphragm resistance and the uncorroded diaphragm resistance, the preset conductivity model is obtained.

[0120] In one embodiment, the preset conductivity model is established by the following formula:

[0121]

[0122] Among them, σ s is the conductivity of the diaphragm to be measured, A is the diaphragm area, σ dr is the black spot conductivity, R dr is the size of the black spot on the diaphragm to be tested.

[0123] For example, through experimental testing, the membrane black spot can be circular, then the size of the membrane black spot to be tested can be the radius of the membrane black spot, and then the area of ​​the corroded membrane is Since the resistance of the uncorroded diaphragm is infinite, the conductivity of the corresponding uncorroded diaphragm is infinite, and then by simplifying the preset conductivity model, the formula corresponding to the preset conductivity model is obtained.

[0124] Based on the formula of the above-mentioned preset conductivity model, the relationship between the diaphragm conductivity and the diaphragm black spot conductivity is established, which facilitates the attribution of the relationship between the diaphragm conductivity and the diaphragm black spot conductivity, and facilitates the establishment of the preset resistance and foreign matter size model in the subsequent steps, thereby improving the accuracy of the preset resistance and foreign matter size model.

[0125] In one embodiment, the preset resistance and foreign body size model is established by the following formula:

[0126]

[0127] Among them, R ISCr is the short-circuit resistance, ρ dr is the density of black spots, σ dr is the black spot conductivity, h is the diaphragm thickness, r is the foreign particle size, ρ m is the foreign matter density, c is the preset foreign matter precipitation amount, k is the foreign matter electrolysis coefficient, and n is the number of foreign matter.

[0128] For example, the specific derivation process of the above-mentioned preset resistance and foreign body size model is as follows: Establish an initial formula for short-circuit resistance:

[0129] Import the formula corresponding to the preset conductivity model into the above initial formula to obtain the first conversion formula:

[0130] The formula corresponding to the preset size model is introduced into the first conversion formula, and the formula corresponding to the preset resistance and foreign body size model is obtained as follows:

[0131] In the above-mentioned embodiment, by establishing a preset resistance and a foreign matter size model corresponding to the short-circuit resistance and the foreign matter particle size, and then establishing a correlation between the foreign matter particle size of the magnetic metal foreign matter and the short-circuit resistance of the battery, the internal short circuit of the battery can be quantitatively attributed, the quantitative analysis error of the positive pole magnetic metal foreign matter particle size and the short-circuit resistance of the battery is reduced, and the control of the positive pole magnetic metal foreign matter is facilitated; the preset resistance and the foreign matter size model are input by the foreign matter particle size for processing, and then the short-circuit resistance of the battery is calculated, which improves the accuracy of calculating the short-circuit resistance of the battery and avoids causing a poor battery k value.

[0132] In one embodiment, Figure 7 As shown, a method for calculating the short-circuit resistance of a battery is provided. Figure 1The processor 102 in the embodiment is taken as an example to illustrate, and the following steps are included:

[0133] Step S710, obtaining the foreign matter particle size corresponding to the magnetic metal foreign matter.

[0134] For the specific description of the above step S710, please refer to the description of the above embodiment, which will not be repeated here.

[0135] Step S720: Based on the preset resistance and the foreign matter size model, the foreign matter particle size is processed to obtain the short-circuit resistance of the battery to be tested.

[0136] For the specific description of the above step S720, please refer to the description of the above embodiment, which will not be repeated here.

[0137] Step S730, querying a preset mapping relationship between internal resistance and voltage drop according to the short-circuit resistance, and obtaining voltage drop data corresponding to the battery to be tested.

[0138] Among them, the preset internal resistance and voltage drop mapping relationship can be obtained by pre-establishing historical test data. For example, the preset internal resistance and voltage drop mapping relationship can be stored in the form of a chart. It should be noted that the larger the short-circuit resistance, the smaller the battery k value (i.e., the voltage drop of the battery per unit time), and thus the better the battery performance, and the smaller the short-circuit resistance, the larger the battery k value, and the worse the battery performance.

[0139] According to the calculated short-circuit resistance, the preset internal resistance and voltage drop mapping relationship is queried to obtain the battery k value of the corresponding battery to be tested, and then according to the battery k value, it is determined whether the performance of the battery to be tested is qualified to avoid causing a poor battery k value.

[0140] It should be understood that although Figures 2 to 7 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figures 2 to 7 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0141] In one embodiment, a battery short-circuit resistance calculation device is also provided, comprising:

[0142] The size acquisition unit is used to acquire the foreign matter particle size corresponding to the magnetic metal foreign matter.

[0143] The resistance calculation unit is used to process the foreign matter particle size based on the preset resistance and foreign matter size model to obtain the short-circuit resistance of the battery to be tested.

[0144] For the specific definition of the battery short-circuit resistance calculation device, please refer to the definition of the battery short-circuit resistance calculation method above, which will not be repeated here. Each module in the above-mentioned battery short-circuit resistance calculation device can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the battery short-circuit resistance calculation system in hardware form, or can be stored in the memory in the battery short-circuit resistance calculation system in software form, so that the processor can call and execute the operations corresponding to the above modules.

[0145] In one embodiment, Fig.11 As shown, a battery short-circuit resistance calculation system is provided, including a processing device 110 and a battery to be tested 120, wherein the processing device 110 is connected to the battery to be tested 120; the processing device 110 is used to execute the steps of any one of the above-mentioned battery short-circuit resistance calculation methods.

[0146] In one example, the processing device 110 is configured to execute the following steps of a method for calculating a battery short-circuit resistance:

[0147] The processing device 110 obtains the foreign particle size of the corresponding magnetic metal foreign matter; based on the preset resistance and foreign matter size model, the foreign particle size is processed to obtain the short-circuit resistance of the battery 120 to be tested, thereby realizing accurate calculation of the battery short-circuit resistance based on the foreign particle size of the magnetic metal foreign matter.

[0148] In the above embodiment, according to the preset resistance and foreign matter size model corresponding to the short-circuit resistance and the foreign matter particle size, the correlation between the foreign matter particle size of the magnetic metal foreign matter and the short-circuit resistance of the battery is established, and the preset resistance and the foreign matter size model are input by the foreign matter particle size for processing, and then the short-circuit resistance of the battery is calculated, so as to quantitatively attribute the internal short circuit of the battery, reduce the quantitative analysis error of the positive pole magnetic metal foreign matter particle size and the battery short-circuit resistance, improve the accuracy of calculating the battery short-circuit resistance, and avoid causing a poor battery k value.

[0149] In one embodiment, a computer-readable storage medium is further provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above-mentioned methods for calculating the short-circuit resistance of a battery are implemented.

[0150] For example, a computer program, when executed by a processor, performs the following steps:

[0151] The foreign particle size of the corresponding magnetic metal foreign matter is obtained; based on the preset resistance and foreign matter size model, the foreign matter particle size is processed to obtain the short-circuit resistance of the battery to be tested, thereby realizing the accurate calculation of the battery short-circuit resistance based on the foreign matter particle size of the magnetic metal foreign matter.

[0152] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing related hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned division operation methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0153] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0154] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for calculating battery short-circuit resistance, characterized in that: The following steps are involved: Obtain the foreign matter particle size corresponding to the magnetic metal foreign matter; Based on the preset resistance and foreign matter size model, the foreign matter particle size is processed to obtain the short-circuit resistance of the battery to be tested.

2. The method for calculating the short-circuit resistance of a battery according to claim 1, characterized in that: The step of processing the foreign matter particle size based on the preset resistance and foreign matter size model to obtain the short-circuit resistance of the battery to be tested includes: Acquire diaphragm detection data corresponding to the diaphragm, black spot detection data corresponding to the black spot, and foreign matter feature data corresponding to the magnetic metal foreign matter; The preset resistance and foreign matter size model is established based on the foreign matter characteristic data, the diaphragm detection data and the black spot detection data.

3. The method for calculating the short-circuit resistance of a battery according to claim 2, characterized in that: The diaphragm detection data includes diaphragm thickness and diaphragm area, the black spot detection data includes black spot density and black spot conductivity, and the foreign matter characteristic data includes foreign matter density, foreign matter quantity and foreign matter electrolysis coefficient; The step of establishing the preset resistance and foreign matter size model according to the foreign matter characteristic data, the diaphragm detection data and the black spot detection data comprises: Performing mass calculation processing on the diaphragm thickness, the black spot density, the foreign matter density, the number of foreign matters and the foreign matter electrolysis coefficient to obtain a preset size model; Performing conductivity calculation processing on the diaphragm area, the black spot conductivity, and the preset size model to obtain a preset conductivity model; The preset resistance and foreign matter size model is obtained according to the preset size model and the preset conductivity model.

4. The method for calculating the short-circuit resistance of a battery according to claim 3, characterized in that: The step of performing mass calculation processing on the diaphragm thickness, the black spot density, the foreign matter density, the number of foreign matters and the foreign matter electrolysis coefficient to obtain a preset size model comprises: Obtaining a preset foreign matter precipitation amount; the preset foreign matter precipitation amount is the foreign matter precipitation amount between the positive electrode member and the diaphragm and / or between the negative electrode member and the diaphragm; Obtaining spot quality according to the size of the black spot on the membrane to be tested, the thickness of the membrane and the density of the black spot; According to the foreign matter particle size, the foreign matter density, the foreign matter quantity and the foreign matter electrolysis coefficient, the mass of the metallic foreign matter exposed from the diaphragm and not corroded is obtained; The preset size model is obtained according to the foreign matter precipitation amount, the spot mass and the metal foreign matter mass.

5. The method for calculating the short-circuit resistance of a battery according to claim 3, characterized in that: The diaphragm area includes the corroded diaphragm area and the uncorroded diaphragm area; the diaphragm resistance is obtained by connecting the resistance of the corroded diaphragm and the resistance of the uncorroded diaphragm in parallel; The corroded diaphragm does not completely isolate the uncorroded diaphragm, so that the resistance of the corroded diaphragm and the resistance of the uncorroded diaphragm are in an equivalent parallel state; The step of performing conductivity calculation processing on the diaphragm area, the black spot conductivity, and the preset size model to obtain the preset conductivity model comprises: Obtaining the diaphragm resistance according to the diaphragm conductivity to be measured, the diaphragm thickness and the diaphragm area; Obtaining the resistance of the corroded diaphragm according to the black spot conductivity, the diaphragm thickness and the corroded diaphragm area; Obtaining the resistance of the uncorroded diaphragm according to the conductivity of the uncorroded diaphragm to be measured, the thickness of the diaphragm and the area of ​​the uncorroded diaphragm; The preset conductivity model is obtained according to the diaphragm resistance, the corroded diaphragm resistance and the uncorroded diaphragm resistance.

6. The method for calculating the short-circuit resistance of a battery according to claim 4, characterized in that: The preset size model is established by the following formula: Among them, R dr is the size of the black spot on the diaphragm to be tested, k is the electrolysis coefficient of the foreign matter, r is the particle size of the foreign matter, ρ m is the foreign matter density, c is the preset foreign matter precipitation amount, ρ dr is the black spot density, h is the diaphragm thickness, and n is the number of foreign matter.

7. The method for calculating the short-circuit resistance of a battery according to claim 5, characterized in that: The preset conductivity model is established by the following formula: Among them, σ s is the conductivity of the diaphragm to be measured, A is the area of ​​the diaphragm, σ dr is the black spot conductivity, R dr is the size of the black spot on the diaphragm to be tested.

8. The method for calculating the short-circuit resistance of a battery according to claim 3, characterized in that: The preset resistance and foreign body size model is established by the following formula: Among them, R ISCr is the short-circuit resistance, ρ dr is the black spot density, σ dr is the black spot conductivity, h is the diaphragm thickness, r is the foreign particle size, ρ m is the foreign matter density, c is the preset foreign matter precipitation amount, k is the foreign matter electrolysis coefficient, and n is the number of foreign matter.

9. The method for calculating the short-circuit resistance of a battery according to any one of claims 1 to 8, characterized in that: After the step of processing the foreign matter particle size based on the preset resistance and foreign matter size model to obtain the short-circuit resistance of the battery to be tested, the method further comprises: According to the short-circuit resistance, a preset internal resistance and voltage drop mapping relationship is queried to obtain voltage drop data corresponding to the battery to be tested.

10. A battery short-circuit resistance calculation system, characterized in that: It includes a processing device and a battery to be tested, wherein the processing device is connected to the battery to be tested; The processing device is used to execute the steps of the battery short-circuit resistance calculation method according to any one of claims 1 to 9.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for calculating the short-circuit resistance of a battery according to any one of claims 1 to 9 are implemented.

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