Simulation method and device for mechanical shock test of battery, and storage medium

Abstract

The simulation method for the mechanical impact test of the battery comprises the following steps: respectively carrying out tensile test on a sample piece of a preset positive plate, a sample piece of a preset negative plate, a sample piece of a preset diaphragm and a sample piece of a preset shell to obtain corresponding mechanical data; and / or respectively carrying out compression test on the components to obtain corresponding mechanical data; according to the material parameters and the mechanical data corresponding to the preset positive plate, the preset negative plate, the preset diaphragm and the preset shell, constructing a battery model; an impact process model is constructed according to the preset impact condition, an impact simulation test is conducted on a battery model corresponding to the preset battery through the impact process model, a simulation test result is obtained, and the simulation test result comprises energy data corresponding to the preset positive plate, the preset negative plate, the preset diaphragm and the preset shell. And performing an impact simulation test on the battery model by using the impact process model, so that the energy change of the preset positive and negative plates, the diaphragm and the shell in the impact process can be quantified.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a simulation method, equipment and storage medium for a battery mechanical impact test. Background Art

[0002] As the energy storage battery with the highest energy density at present, lithium-ion batteries are widely used in various power tools, electric vehicles and various portable devices. However, lithium-ion batteries also have some safety issues, such as thermal runaway of lithium-ion batteries caused by mechanical abuse. At this time, the deformation of lithium-ion batteries will cause damage to the pole pieces, diaphragms and other structural parts inside the battery cell, thereby causing internal short circuits. At present, the ways to evaluate such safety risks of batteries include: heavy object impact method and extrusion method, that is, to measure the battery cell by heavy object impact or extrusion method. However, these evaluation methods have lags.

[0003] Thermal runaway of lithium-ion batteries caused by mechanical abuse is usually accompanied by energy changes. However, this energy change cannot be quantified. Therefore, how to quantify the energy generated in battery thermal runaway is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The main technical problem solved by the present invention is to quantify the energy generated in battery thermal runaway.

[0005] According to the first aspect, an embodiment provides a simulation method for a battery mechanical impact test, wherein the preset battery includes a plurality of preset positive electrode sheets, a plurality of preset negative electrode sheets, a plurality of preset diaphragms, and a preset housing, and the method includes:

[0006] Performing a tensile test on the sample of the preset positive electrode sheet, the sample of the preset negative electrode sheet, the sample of the preset diaphragm and the sample of the preset shell respectively to obtain corresponding mechanical data; and / or, performing a compression test on the sample of the preset positive electrode sheet, the sample of the preset negative electrode sheet, the sample of the preset diaphragm and the sample of the preset shell respectively to obtain corresponding mechanical data;

[0007] Constructing a battery model corresponding to the preset battery according to the material parameters and mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset separator and the preset shell;

[0008] An impact process model is constructed according to preset impact conditions, and an impact simulation test is performed on a battery model corresponding to the preset battery using the impact process model to obtain a simulation test result, which includes energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset casing.

[0009] According to the second aspect, an embodiment provides a simulation device for a battery mechanical impact test, the device comprising:

[0010] An acquisition unit is used to acquire mechanical data of a preset positive electrode sheet, a preset negative electrode sheet, a preset diaphragm, and a preset shell; the mechanical data of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm, and the preset shell are obtained by respectively performing a tensile test and / or a compression test on a sample of the preset positive electrode sheet, a sample of the preset negative electrode sheet, a sample of the preset diaphragm, and a sample of the preset shell;

[0011] A construction unit is used to construct a battery model corresponding to a preset battery according to the material parameters and mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell; it is also used to construct an impact process model according to preset impact conditions, and use the impact process model to perform an impact simulation test on the battery model corresponding to the preset battery to obtain a simulation test result, wherein the simulation test result includes energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell; wherein the energy data is used to provide a reference for the design of the preset battery.

[0012] According to a third aspect, an embodiment provides a computer-readable storage medium, comprising a program, wherein the program can be executed by a processor to implement the above method.

[0013] According to a fourth aspect, an embodiment provides a computer program product, comprising a computer program and / or instructions, wherein the computer program and / or instructions implement the above method when executed by a processor.

[0014] According to a simulation method for a battery mechanical impact test of the above embodiment, a battery model corresponding to a preset battery is constructed by inputting material parameters and mechanical data corresponding to a preset positive electrode sheet, a preset negative electrode sheet, a preset diaphragm and a preset shell into a preset model software; and an impact process model is constructed according to preset impact conditions; after an impact simulation test is performed on the battery model using the impact process model, energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell can be obtained, thereby quantifying the energy changes of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell during the impact process, so as to provide a reference for the design of the preset battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a flow chart of a simulation method for a battery mechanical impact test provided in this embodiment;

[0016] Figure 2 A schematic diagram of a cell of a lithium-ion battery A provided in this embodiment after an impact test;

[0017] Figure 3 A schematic diagram of another cell of the lithium-ion battery A provided in this embodiment after the impact test;

[0018] Figure 4 A schematic diagram of a cell of a lithium-ion battery B provided in this embodiment after an impact test;

[0019] Figure 5 A schematic diagram of another cell of the lithium-ion battery B provided in this embodiment after the impact test;

[0020] Figure 6 This is a structural block diagram of a battery mechanical impact test simulation device provided in this embodiment. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0022] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0023] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0024] The following is the definition of battery structural parts:

[0025] 1. Positive electrode active layer

[0026] The positive electrode active layer is the key part of the positive electrode of the lithium-ion battery, mainly composed of active materials, conductive agents and binders. These materials are coated on the surface of the positive electrode current collector to form a porous composite material layer. The main function of the positive electrode active layer is to store and release lithium ions, and it is the main place for the battery to carry out electrochemical reactions. During the charging process, lithium ions are embedded from the electrolyte into the material of the positive electrode active layer; during the discharge process, lithium ions are released from the positive electrode active layer and enter the electrolyte to complete the charge transfer.

[0027] 2. Negative electrode active layer

[0028] The negative electrode active layer is similar to the positive electrode active layer, and is also composed of active materials, conductive agents and binders, and is coated on the surface of the negative electrode current collector. The main function of the negative electrode active layer is to receive and store lithium ions that migrate from the positive electrode. During the charging process, lithium ions are embedded from the electrolyte into the material of the negative electrode active layer; during the discharge process, lithium ions are released from the negative electrode active layer and return to the electrolyte, completing the charge transfer.

[0029] 3. Positive electrode current collector

[0030] The positive electrode current collector is a component of the positive electrode of a lithium-ion battery. Its main function is to carry the positive electrode active layer and collect and output the current generated by the active layer. During the battery charging and discharging process, the positive electrode current collector provides a transmission channel for electrons, accelerates the transfer of charges, reduces the polarization phenomenon in the electrochemical reaction, and improves the battery's charging and discharging efficiency.

[0031] 4. Negative electrode current collector

[0032] The negative electrode current collector is a component of the negative electrode of a lithium-ion battery. Its function is similar to that of the positive electrode current collector, which mainly carries the negative electrode active layer and collects and outputs the current generated by the active layer. During the battery charging and discharging process, the negative electrode current collector also provides a transmission channel for electrons, accelerating the transfer of charge.

[0033] At present, lithium-ion batteries have the following safety issues: thermal runaway of lithium-ion batteries caused by mechanical abuse. Deformation of lithium-ion batteries will cause damage to the pole pieces, diaphragms and other structural parts inside the battery cell, which will cause internal short circuits. At present, the ways to evaluate such safety risks of batteries include: heavy object impact method and extrusion method, that is, the battery cell is measured by heavy object impact or extrusion method, but these evaluation methods have lags. Thermal runaway of lithium-ion batteries caused by mechanical abuse is usually accompanied by energy changes, but these energy changes cannot be quantified.

[0034] Based on this, the solution of the present invention is proposed. In an embodiment of the present invention, by inputting the material parameters and mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell into the preset model software, a battery model corresponding to the preset battery is constructed; and an impact process model is constructed according to the preset impact conditions; after the battery model is subjected to an impact simulation test using the impact process model, the energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell can be obtained, thereby realizing the quantification of the energy changes of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell during the impact process, so as to provide a reference for the design of the preset battery. This is described in detail through some embodiments below.

[0035] Example 1, please refer to Figure 1 , Figure 1 is a flow chart of a simulation method for a battery mechanical impact test provided in this embodiment, such as Figure 1 As shown, the method specifically includes the following steps 101-103:

[0036] Step 101, respectively perform tensile tests on samples of preset positive electrode sheets, samples of preset negative electrode sheets, samples of preset diaphragms, and samples of preset shells to obtain corresponding mechanical data; and / or respectively perform compression tests on samples of preset positive electrode sheets, samples of preset negative electrode sheets, samples of preset diaphragms, and samples of preset shells to obtain corresponding mechanical data.

[0037] Here, the plurality of preset positive electrode sheets and the plurality of preset negative electrode sheets belong to the electrode sheet composition of the preset battery. The preset battery can be any type of battery. Exemplarily, the preset battery can be a lithium-ion battery or a nickel-chromium battery, and this application does not make any limitation on this.

[0038] The following descriptions are all based on lithium-ion batteries as an example. The preset battery can be a battery in the design stage, that is, the specifications of its preset positive electrode sheet, preset negative electrode sheet, preset separator and preset shell are known. It should be noted that the sample of the positive electrode sheet can be produced according to the design parameters of the positive electrode sheet; the sample of the negative electrode sheet can be produced according to the design parameters of the negative electrode sheet; the sample of the preset separator can be produced according to the design parameters of the separator; the sample of the preset shell can be produced according to the design parameters of the shell.

[0039] In practical applications, the samples for tensile testing are the same as those for compression testing, including the following:

[0040] Metal materials (housing, current collector): The physical and chemical properties of metal materials are nearly the same in all directions, that is, the physical and chemical properties of metal materials in the transverse and longitudinal directions are nearly the same. In the actual measurement process, you can choose to measure the mechanical data in one direction (transverse or longitudinal). When making a metal housing structure (a sample of a preset housing), it can be made into a sample of any font. For example, the metal housing structure can be made into an "I"-shaped sample; when making a current collector structure, it can be made into a sample of any font. For example, the current collector structure can be made into a long strip sample.

[0041] Plastic materials (diaphragms): The physical and chemical properties of plastic materials are different in all directions, that is, the physical and chemical properties of plastic materials in the horizontal and vertical directions are different. In the actual measurement process, it is necessary to measure not only the horizontal mechanical data of plastic materials, but also the vertical mechanical data of plastic materials. When making plastic structural parts (preset diaphragms), they can be made into samples of any font. For example, the plastic structural parts can be made into rectangular samples.

[0042] Positive and negative electrodes: The physical and chemical properties of the positive electrode are close to the same in all directions, that is, the physical and chemical properties of the positive electrode in the horizontal and vertical directions are close to the same. In the actual measurement process, you can choose to measure the mechanical data in one direction (horizontal or vertical). When making the positive electrode structure (preset positive electrode sample), it can be made into a sample of any font. For example, the positive electrode structure can be made into a rectangular sample; The physical and chemical properties of the negative electrode are close to the same in all directions, that is, the physical and chemical properties of the negative electrode in the horizontal and vertical directions are close to the same. In the actual measurement process, you can choose to measure the mechanical data in one direction (horizontal or vertical). When making the negative electrode structure (preset negative electrode sample), it can be made into a sample of any font. For example, the negative electrode structure can be made into a rectangular sample.

[0043] It should be noted that the positive electrode sheet structure and the negative electrode sheet structure can also be made into circular samples.

[0044] In practical applications, the number of samples of the positive electrode sheet and the number of samples of the negative electrode sheet can be any value. For example, the number of samples of the positive electrode sheet can be 25, and the number of samples of the negative electrode sheet can also be 25.

[0045] It should be noted that the tensile force in the tensile test can be any value of tensile force; the tensile speed can be any value of tensile speed.

[0046] In practical applications, the tensile test standard in the national standard can be selected, and a tensile tester or a device with a tensile function can be used to perform a tensile test on the above-mentioned preset battery to obtain mechanical data such as tensile strength, elongation at break, and elastic modulus. Among them, the tensile force corresponding to the tensile test standard can be any value of tensile force, for example, the tensile force can be 1KN, and the tensile speed corresponding to the tensile test standard can be any value of tensile speed, for example, the tensile speed can be 250mm / min.

[0047] Here, the mechanical data obtained by the tensile test includes at least one of the following: tensile strength, elongation at break, and elastic modulus.

[0048] It should be noted that the tensile strength can characterize the maximum uniform plastic deformation stress that the sample of the preset positive electrode sheet, the sample of the preset negative electrode sheet, the sample of the preset diaphragm, and the sample of the preset shell can withstand during the stretching process.

[0049] It should be noted that the elongation at break can characterize the ratio of the elongated length after stretching to the length before stretching of the preset positive electrode sheet sample, the preset negative electrode sheet sample, the preset diaphragm sample and the preset shell sample when they are broken by external force.

[0050] It should be noted that the elastic modulus can be used to measure the ability of the preset positive electrode sample, the preset negative electrode sample, the preset diaphragm sample and the preset housing sample to resist elastic deformation.

[0051] It should be noted that the compression force in the compression test can be any value of the compression force; the compression speed can be any value of the compression speed.

[0052] In practical applications, the compression test standard in the national standard can be selected, and the compression test can be performed on the above-mentioned preset battery using an extruder, a compressor or a device with a compression function to obtain data such as compression deformation and compression rate. Among them, the compression force corresponding to the compression test standard can be any value of compression force, for example, the compression force can be 1.3KN, and the compression speed corresponding to the compression test standard can be any value of compression speed, for example, the compression speed can be 0.1mm / min.

[0053] Here, the mechanical data obtained by the compression test includes at least one of the following: compression deformation and compression ratio.

[0054] It should be noted that the compression deformation amount can characterize the deformation amount of the preset positive electrode sample, the preset negative electrode sample, the preset diaphragm sample and the preset shell sample along the compression direction (usually radial or height direction) when they are subjected to compression force.

[0055] It should be noted that the compression rate can characterize the ratio of the deformation amount generated by the sample of the preset positive electrode sheet, the sample of the preset negative electrode sheet, the sample of the preset diaphragm and the sample of the preset shell when subjected to the compression force to the original size.

[0056] Step 102: construct a battery model corresponding to the preset battery according to the material parameters and mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset separator and the preset shell.

[0057] Here, when constructing a battery model corresponding to a preset battery, the mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell can be homogenized to obtain homogenized mechanical data; the material parameters and homogenized mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell are input into the preset model software to construct a first battery model corresponding to the preset battery.

[0058] It should be noted that the preset model software may be any simulation software, and illustratively, the preset model software may be Abaqus engineering simulation software or ANSYS general finite element analysis software, and this application does not make any limitation on this.

[0059] It should be noted that the mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell are homogenized, that is, the differences between the mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell are not considered, and a simple battery model, namely the first battery model, is constructed based on the obtained homogenized mechanical data and the obtained material parameters.

[0060] In practical applications, the number of grids corresponding to the first battery model corresponding to the preset battery is relatively small, so fast calculation can be performed to improve calculation efficiency.

[0061] Here, when constructing a battery model corresponding to a preset battery, the material parameters and mechanical data corresponding to the preset positive electrode sheet, preset negative electrode sheet, preset diaphragm and preset shell can also be input into the preset model software to construct a second battery model corresponding to the preset battery.

[0062] It should be noted that in actual applications, there may be differences in the mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell. By inputting the mechanical data corresponding to the different preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell together with the material parameters into the preset model software, a second battery model different from the first battery model can be constructed.

[0063] It should be noted that the second battery model corresponding to the preset battery has a larger number of grids than the first battery model corresponding to the preset battery, and has greater requirements for computer hardware. The accuracy of the calculation results is higher than that of the first battery model.

[0064] It should be noted that the material parameters corresponding to the preset positive electrode sheet can be any parameters. For example, the material parameters corresponding to the preset positive electrode sheet can be lithium cobalt oxide, nickel cobalt manganese ternary material, lithium manganese oxide, lithium iron phosphate or lithium metal. The material parameters corresponding to the preset negative electrode sheet can be any parameters. For example, the material parameters corresponding to the preset negative electrode sheet can be graphite, silicon-based materials, metal oxides or metal sulfides. The material parameters corresponding to the preset diaphragm can be any parameters. For example, the material parameters corresponding to the preset diaphragm can be polyolefin materials, non-woven membranes, microporous membranes, composite membranes or modified microporous membranes. The material parameters corresponding to the preset shell can be any parameters. For example, the material parameters corresponding to the preset shell can be aluminum alloy or steel.

[0065] Step 103, construct an impact process model according to the preset impact conditions, and use the impact process model to perform an impact simulation test on the battery model corresponding to the preset battery to obtain a simulation test result, which includes energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset casing.

[0066] It should be noted that when the impact process model is constructed according to the preset impact conditions, the preset impact conditions can be input into the simulation software to construct the impact process model. Here, the simulation software can be any software. For example, the simulation software can be Abaqus engineering simulation software or ANSYS general finite element analysis software. This application does not make any limitation on this.

[0067] It should be noted that the impact process model is used to perform an impact simulation test on the battery model corresponding to the preset battery, and the energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset casing are obtained. That is, the battery model corresponding to the preset battery is subjected to an impact simulation test according to the preset impact conditions, and the energy absorbed by the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset casing during the impact process is quantified, so as to reasonably design the preset battery according to the energy data.

[0068] Here, the preset impact condition includes a preset impact speed, a preset impact angle, and a preset impact force.

[0069] In practical applications, the preset impact velocity can be any value of impact velocity; the preset impact angle can be any value of impact angle; the preset impact force can be any value of impact force, and this application does not impose any limitation on this.

[0070] Here, the preset battery is designed according to the energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset separator and the preset casing to obtain the target battery.

[0071] Here, when designing a preset battery to obtain a target battery, the energy distribution corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell can be determined based on the energy data; when the energy distribution does not meet the design requirements, the design parameters of at least one of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and / or the preset shell are adjusted according to the energy distribution to obtain the target battery; wherein the design parameters include at least one of material parameters, structural parameters and preset numbers.

[0072] It should be noted that the purpose of determining the energy distribution corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset casing based on the energy data is: to judge whether the energy distribution corresponding to the preset battery meets the design requirements according to the energy absorbed by the preset positive electrode sheet during the impact, the energy absorbed by the preset negative electrode sheet during the impact, the energy absorbed by the preset diaphragm during the impact and the energy absorbed by the preset casing during the impact.

[0073] Exemplarily, during an impact, when the energy absorbed by a preset positive electrode sheet accounts for a larger proportion of the total energy absorbed by a preset battery than the energy absorbed by a preset outer shell accounts for a larger proportion of the total energy absorbed by the preset battery, it indicates that the energy impact obtained by the preset positive electrode sheet is greater than the energy impact obtained by the preset outer shell. At this time, the positive electrode sheet of the constructed preset battery is prone to breakage during the impact process. Therefore, the energy distribution of the preset battery does not meet the design requirements.

[0074] Exemplarily, during an impact, when the energy absorbed by a preset negative electrode sheet accounts for a greater proportion of the total energy absorbed by a preset battery than the energy absorbed by a preset outer shell accounts for a greater proportion of the total energy absorbed by the preset battery, it means that the energy impact obtained by the preset negative electrode sheet is greater than the energy impact obtained by the preset outer shell. At this time, the negative electrode sheet of the constructed preset battery is prone to breakage during the impact process. Therefore, the energy distribution of the preset battery does not meet the design requirements.

[0075] That is to say, when judging whether the energy distribution corresponding to the preset battery meets the design requirements, it is mainly based on the distribution of the energy absorbed by the preset positive electrode sheet during the impact, the energy absorbed by the preset negative electrode sheet during the impact, the energy absorbed by the preset diaphragm during the impact, and the energy absorbed by the preset casing during the impact to further judge whether the energy distribution corresponding to the preset battery meets the design requirements.

[0076] In actual applications, when designing a preset battery based on the energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell, at least one of the material, thickness, number, size and shape of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell can be adjusted.

[0077] Exemplarily, during an impact, when the proportion of energy absorbed by a preset shell in the total energy absorbed by a preset battery is smaller than the proportion of energy absorbed by a preset positive electrode in the total energy absorbed by the preset battery, the energy absorbed by the preset shell can be increased by adjusting the thickness, material, size or shape of the preset shell, that is, the preset shell bears a greater energy impact during the impact, so as to weaken the energy impact borne by the preset positive electrode during the impact.

[0078] Exemplarily, during an impact, when the proportion of energy absorbed by a preset shell in the total energy absorbed by a preset battery is smaller than the proportion of energy absorbed by a preset negative electrode sheet in the total energy absorbed by the preset battery, the energy absorbed by the preset shell can be increased by adjusting the thickness, material, size or shape of the preset shell, that is, the preset shell bears a greater energy impact during the impact, so as to weaken the energy impact borne by the preset negative electrode sheet during the impact.

[0079] In actual applications, simulation test results can be displayed to facilitate staff viewing and analysis.

[0080] The following is an explanation based on the test content:

[0081] Subject: Cylindrical 21700 lithium-ion battery.

[0082] Mechanical shock item: heavy object impact (national standard).

[0083] Scheme design: The steel shell in Scheme A (multiple lithium-ion batteries A) is steel shell A, and the steel shell in Scheme B (multiple lithium-ion batteries B) is steel shell B.

[0084] Experimental results: Table 1, mechanical data of cylindrical 21700 lithium-ion battery; Table 2, energy absorbed by lithium-ion batteries A and B during heavy object impact and their corresponding energy proportions; Table 3, test results of lithium-ion batteries.

[0085] Table 1 Mechanical data of cylindrical 21700 lithium-ion battery

[0086]

[0087]

[0088] In Table 1, among the mechanical data corresponding to the positive electrode active layer, the negative electrode active layer, the positive electrode current collector, the negative electrode current collector, the separator MD, the separator TD, the steel shell A and the steel shell B, the tensile strength corresponding to the steel shell B is the largest, followed by the tensile strength corresponding to the steel shell A. It can be seen that both the steel shell A and the steel shell B have large tensile strengths, while the tensile strengths corresponding to the positive electrode active layer, the negative electrode active layer, the positive electrode current collector, the negative electrode current collector, the separator MD and the separator TD are relatively small.

[0089] Table 2. Energy absorbed by lithium-ion batteries A and B during heavy object impact and their corresponding energy proportions

[0090]

[0091] In Table 2, there is a significant difference between the energy absorbed by lithium-ion battery A and the energy absorbed by lithium-ion battery B. Specifically, the energy absorbed by the positive electrode active layer in lithium-ion battery A is the highest, accounting for 31.7%, followed by the energy absorbed by the steel shell and the energy absorbed by the negative electrode active layer, accounting for 29.1% and 23.4%, respectively. The energy absorbed by the steel shell in lithium-ion battery B is the highest, accounting for 42.7%, followed by the energy absorbed by the positive electrode active layer and the energy absorbed by the negative electrode active layer, accounting for 23.5% and 19.6%, respectively.

[0092] It can be seen that compared with lithium-ion battery A, lithium-ion battery B increases the energy absorption of the steel shell and reduces the energy absorption of the positive active layer, negative active layer, positive current collector, negative current collector, and diaphragm, especially the energy absorption of the positive active layer and the negative active layer. In this way, during the impact of heavy objects, the energy impact borne by the pole piece of lithium-ion battery B is relatively small, and it is not easy to be damaged. In other words, lithium-ion battery B has stronger impact resistance than lithium-ion battery A. Figure 2 , 3 As shown in the figure, after the cell of lithium-ion battery A has been impact tested, the area of ​​the electrode that is lit is the damaged area of ​​the cell; after another cell of lithium-ion battery A has been impact tested, the area of ​​the electrode that is lit is the damaged area of ​​the cell; therefore, the cell of lithium-ion battery A has not passed the impact test, that is, the cell of lithium-ion battery A is unqualified. Figure 4 , 5 As shown, after the cell of lithium-ion battery B has passed the impact test, the electrode therein is not damaged; this indicates that the cell of lithium-ion battery B can pass the impact test, that is, the cell of lithium-ion battery B is a qualified cell, and it also indicates that the probability of short circuit caused by damage inside lithium-ion battery B is lower than the probability of short circuit caused by damage inside lithium-ion battery A, thus, the probability of thermal runaway of lithium-ion cells can be effectively reduced.

[0093] Table 3. Test results of lithium-ion batteries

[0094]

[0095] In Table 3, the lithium-ion battery B in Scheme B has a stronger impact resistance than the lithium-ion battery A in Scheme A, that is, the lithium-ion battery B is easier to pass the impact test than the lithium-ion battery A; moreover, the battery cell of the lithium-ion battery B is less likely to have a low voltage than the battery cell of the lithium-ion battery A, that is, the lithium-ion battery B is less likely to have a short circuit (internal diaphragm damage) than the lithium-ion battery A. It should be noted that the higher the proportion of low voltage in the battery cell, the higher the proportion of internal short circuits in the lithium-ion battery cell, and the short circuit process will be accompanied by heat generation, which can easily lead to battery cell failure.

[0096] In the present embodiment, a simulation method for a battery mechanical impact test is provided, the method comprising: performing a tensile test on a sample of a preset positive electrode sheet, a sample of a preset negative electrode sheet, a sample of a preset diaphragm, and a sample of a preset shell, respectively, to obtain corresponding mechanical data; and / or performing a compression test on a sample of a preset positive electrode sheet, a sample of a preset negative electrode sheet, a sample of a preset diaphragm, and a sample of a preset shell, respectively, to obtain corresponding mechanical data; constructing a battery model corresponding to a preset battery according to material parameters and mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm, and the preset shell; constructing an impact process model according to preset impact conditions, and using the impact process model to perform an impact simulation test on the battery model corresponding to the preset battery, to obtain a simulation test result, the simulation test result including energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm, and the preset shell. A battery model corresponding to the preset battery is constructed by inputting material parameters and mechanical data corresponding to a preset positive electrode sheet, a preset negative electrode sheet, a preset diaphragm and a preset shell into a preset model software; and an impact process model is constructed according to preset impact conditions; after an impact simulation test is performed on the battery model using the impact process model, energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell can be obtained, thereby quantifying the energy changes of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell during the impact process, so as to provide a reference for the design of the preset battery.

[0097] The present invention also provides a simulation device for battery mechanical impact test, such as Figure 6 The structure block diagram of a battery mechanical impact test simulation device shown in FIG. The device includes an acquisition unit 201 and a construction unit 202:

[0098] The acquisition unit 201 is used to acquire mechanical data of a preset positive electrode sheet, a preset negative electrode sheet, a preset diaphragm, and a preset shell; the mechanical data of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm, and the preset shell are obtained by performing tensile tests and / or compression tests on samples of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm, and the preset shell, respectively. That is, it is used to execute the above step 101. The specific process is shown in the above step 101, which will not be described in detail here.

[0099] The construction unit 202 is used to construct a battery model corresponding to the preset battery according to the material parameters and mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell; it is also used to construct an impact process model according to the preset impact conditions, and use the impact process model to perform an impact simulation test on the battery model corresponding to the preset battery to obtain a simulation test result, the simulation test result includes the energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell; wherein the energy data is used to provide a reference for the design of the preset battery. That is, it is used to execute the above steps 102 and 103. The specific process is shown in the above steps 102 and 103, which will not be repeated here.

[0100] A simulation device for a mechanical impact test of a battery provided in an embodiment of the present application, wherein an acquisition unit is used to acquire mechanical data of a preset positive electrode sheet, a preset negative electrode sheet, a preset diaphragm and a preset shell; the mechanical data of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell are obtained by respectively performing tensile tests and / or compression tests on samples of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell; a construction unit is used to construct a battery model corresponding to a preset battery according to material parameters and mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell; and is also used to construct an impact process model according to preset impact conditions, and use the impact process model to perform an impact simulation test on the battery model corresponding to the preset battery to obtain a simulation test result, wherein the simulation test result includes energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell. A battery model corresponding to the preset battery is constructed by inputting material parameters and mechanical data corresponding to a preset positive electrode sheet, a preset negative electrode sheet, a preset diaphragm and a preset shell into a preset model software; and an impact process model is constructed according to preset impact conditions; after an impact simulation test is performed on the battery model using the impact process model, energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell can be obtained, thereby quantifying the energy changes of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell during the impact process, so as to provide a reference for the design of the preset battery.

[0101] Those skilled in the art will appreciate that all or part of the functions of the various methods in the above-mentioned embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, and the storage medium can include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to implement the above-mentioned functions. For example, the program is stored in the memory of the device, and when the program in the memory is executed by the processor, all or part of the above-mentioned functions can be implemented. In addition, when all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can also be stored in a storage medium such as a server, another computer, disk, optical disk, flash disk or mobile hard disk, and can be downloaded or copied and saved in the memory of the local device, or the system of the local device is updated, and when the program in the memory is executed by the processor, all or part of the functions in the above-mentioned embodiments can be implemented.

[0102] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A simulation method for battery mechanical impact test, characterized in that: The preset battery includes a plurality of preset positive electrode sheets, a plurality of preset negative electrode sheets, a plurality of preset separators and a preset casing, and the method includes: Performing a tensile test on the sample of the preset positive electrode sheet, the sample of the preset negative electrode sheet, the sample of the preset diaphragm and the sample of the preset shell respectively to obtain corresponding mechanical data; and / or, performing a compression test on the sample of the preset positive electrode sheet, the sample of the preset negative electrode sheet, the sample of the preset diaphragm and the sample of the preset shell respectively to obtain corresponding mechanical data; Constructing a battery model corresponding to the preset battery according to the material parameters and mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset separator and the preset shell; An impact process model is constructed according to preset impact conditions, and an impact simulation test is performed on a battery model corresponding to the preset battery using the impact process model to obtain a simulation test result, which includes energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset casing.

2. The method according to claim 1, characterized in that The method of constructing a battery model corresponding to the preset battery according to the material parameters and mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset separator, and the preset shell includes: Performing homogenization processing on the mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset housing to obtain homogenized mechanical data; Inputting the material parameters corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset separator and the preset shell and the homogenized mechanical data into the preset model software to construct a first battery model corresponding to the preset battery; Alternatively, the material parameters and the mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset housing are input into the preset model software to construct a second battery model corresponding to the preset battery.

3. The method according to claim 1 or 2, characterized in that The preset impact conditions include a preset impact speed, a preset impact angle, and a preset impact force.

4. The method according to claim 1, characterized in that The method further comprises: The preset battery is designed according to the energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset separator and the preset casing to obtain a target battery.

5. The method according to claim 4, characterized in that The step of designing the preset battery according to the energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset separator, and the preset housing to obtain a target battery includes: Based on the energy data, determining energy distribution corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset separator, and the preset housing; When the energy distribution does not meet the design requirements, the design parameters of at least one of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and / or the preset casing are adjusted according to the energy distribution to obtain the target battery; wherein the design parameters include at least one of material parameters, structural parameters and preset numbers.

6. The method according to claim 1, characterized in that The method further comprises: The simulation test results are displayed.

7. The method according to any one of claims 4 to 6, characterized in that The mechanical data obtained from the tensile test includes at least one of the following: tensile strength, elongation at break, and elastic modulus; The mechanical data obtained from the compression test includes at least one of the following: compression deformation and compression rate.

8. A simulation device for battery mechanical impact test, characterized in that: The device comprises: An acquisition unit is used to acquire mechanical data of a preset positive electrode sheet, a preset negative electrode sheet, a preset diaphragm, and a preset shell; the mechanical data of the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm, and the preset shell are obtained by respectively performing a tensile test and / or a compression test on a sample of the preset positive electrode sheet, a sample of the preset negative electrode sheet, a sample of the preset diaphragm, and a sample of the preset shell; A construction unit is used to construct a battery model corresponding to a preset battery according to the material parameters and mechanical data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell; it is also used to construct an impact process model according to preset impact conditions, and use the impact process model to perform an impact simulation test on the battery model corresponding to the preset battery to obtain a simulation test result, wherein the simulation test result includes energy data corresponding to the preset positive electrode sheet, the preset negative electrode sheet, the preset diaphragm and the preset shell; wherein the energy data is used to provide a reference for the design of the preset battery.

9. A computer-readable storage medium, characterized in that: The method comprises a program which can be executed by a processor to implement the method according to any one of claims 1 to 7.

10. A computer program product comprising a computer program and / or instructions, characterized in that: When the computer program and / or the instructions are executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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