Battery expansion force testing method, device, equipment, storage medium and program product

Abstract

The invention relates to a battery expansion force testing method, device and equipment, a storage medium and a program product. The method comprises the following steps: acquiring a first physical characteristic parameter at a first preset position of a constraint member outside a to-be-tested battery, and determining an acting force of the to-be-tested battery under the first physical characteristic parameter according to the first physical characteristic parameter and an acting force model corresponding to a sample constraint member matched with the constraint member, the expansion force test result of the to-be-tested battery is determined according to the acting force under the first physical characteristic parameter, so that nondestructive testing of the expansion force of the to-be-tested battery is realized under the condition that the to-be-tested battery is not disassembled, the obtained expansion force test result can more accurately reflect the actual expansion force in the battery when the battery is returned to a factory, and the test efficiency is improved. And the difference between the expansion force test result and the actual expansion force in the battery when the battery is returned to a factory is reduced.

Description

Technical Field

[0001] This application relates to the technical field of battery testing, and particularly to a method, device, equipment, storage medium, and program product for testing the expansion force of a battery. Background Art

[0002] The expansion force test of returned batteries is crucial for the reliability of product design. For example, based on the tested expansion force, parameters of battery cells in the battery can be designed, and the strength of end plates or steel strips for binding the battery can be determined. The battery can include a battery module or a battery pack.

[0003] Currently, after the battery is returned to the factory, the returned battery is disassembled, and a mechanical sensor is implanted into the battery to test the expansion force inside the battery through the mechanical sensor. However, this method has the problem that there is a large difference between the tested expansion force and the actual expansion force inside the battery when it is returned to the factory. Summary of the Invention

[0004] Based on this, it is necessary to provide a method, device, equipment, storage medium, and program product for testing the expansion force of a battery that can reduce the difference between the tested expansion force of the battery and the actual expansion force inside the battery when it is returned to the factory for the above technical problems.

[0005] In a first aspect, this application provides a method for testing the expansion force of a battery. The method includes:

[0006] Obtain the first physical property parameter at the first preset position of the binding member outside the battery to be tested;

[0007] According to the first physical property parameter and the force model corresponding to the sample binding member that matches the binding member, determine the force of the battery to be tested under the first physical property parameter; the force model is used to characterize the corresponding relationship between the force applied to the target position in the sample binding member and the physical property parameter. The force model includes the force model corresponding to the physical property parameter type of the sample binding member. The first preset position matches the target position, and the physical property parameter type is the same as the parameter type of the first physical property parameter;

[0008] Determine the test result of the expansion force of the battery to be tested according to the force under the first physical property parameter.

[0009] The battery expansion force testing method provided in this embodiment determines the force of the battery under test at the first physical characteristic parameter by obtaining the first physical characteristic parameter at the first preset position of the restraint outside the battery under test, and then determines the expansion force test result of the battery under test according to the force at the first physical characteristic parameter. Thus, without disassembling the battery under test, the expansion force of the battery under test can be detected nondestructively, so that the obtained expansion force test result can more accurately reflect the actual expansion force inside the battery when it is returned to the factory, reducing the difference between the expansion force test result and the actual expansion force inside the battery when it is returned to the factory.

[0010] In one embodiment, the first physical characteristic parameter includes at least one of an electrical parameter, a magnetic parameter, and a mechanical parameter.

[0011] In this embodiment, the first physical characteristic parameter includes at least one of an electrical parameter, a magnetic parameter, and a mechanical parameter, so as to obtain the expansion force test results under diverse physical characteristic parameters based on the diverse physical characteristic parameters and the corresponding force models, providing more abundant and diverse analysis data for analyzing the expansion force of the battery.

[0012] In one embodiment, the restraint includes a steel strip, and the first physical characteristic parameter includes an electrical parameter, which is the electrical parameter detected by an electrical parameter tester at the first preset position.

[0013] In this embodiment, when the restraint is a steel strip, the expansion force test result of the battery under test is determined by obtaining the electrical parameter of the steel strip and the corresponding force model, realizing the nondestructive detection of the expansion force of the battery without disassembling the structure of the battery.

[0014] In one embodiment, the restraint includes an end plate and / or a cross beam, and the first physical characteristic parameter includes a magnetic parameter, which is the magnetic parameter detected by a magnetic parameter tester at the first preset position.

[0015] In this embodiment, when the restraint is an end plate and / or a cross beam, the expansion force test result of the battery under test is determined by obtaining the magnetic parameter of the end plate and / or the cross beam and the corresponding force model, realizing the nondestructive detection of the expansion force of the battery without disassembling the structure of the battery.

[0016] In one embodiment, the restraint includes at least one of a steel strip, an end plate, and a cross beam, and the first physical characteristic parameter includes a mechanical parameter, which is the mechanical parameter detected by a mechanical parameter tester at the first preset position.

[0017] In this embodiment, when the restraint member includes at least one of a steel strip, an end plate, and a cross beam, by obtaining the mechanical parameters of the restraint member and the corresponding force model, the expansion force test result of the battery to be tested is determined, realizing non-destructive detection of the expansion force of the battery without disassembling the battery structure.

[0018] In one embodiment, the method further includes:

[0019] Obtaining the physical property parameters of the target position in the sample restraint member under the action of a force;

[0020] Constructing a force model according to the force and the physical property parameters under the action of the force.

[0021] In this embodiment, by obtaining the physical property parameters of the target position in the sample restraint member under the action of a force, and constructing a force model according to the force and the physical property parameters under the action of the force, it provides a basis for determining the force of the battery to be tested under the first physical property parameter according to the first physical property parameter and the force model corresponding to the parameter type of the pre-constructed first physical property parameter.

[0022] In one embodiment, the sample restraint member includes a sample steel strip. Obtaining the physical property parameters of the target position in the sample restraint member under the action of a force includes:

[0023] Collecting the physical property parameters of the target position under different tensile forces through a physical property tester;

[0024] Wherein, if the physical property tester includes an electrical parameter tester, the physical property parameters include electrical parameters; if the physical property tester includes a mechanical parameter tester, the physical property parameters include mechanical parameters.

[0025] In this embodiment, by collecting the physical property parameters of the target position under different tensile forces through a physical property tester, it provides a basis for constructing a force model for characterizing the corresponding relationship between the tensile force and the physical property parameters.

[0026] In one embodiment, the sample restraint member includes a sample fixing member, and the sample fixing member includes at least one of a sample end plate and a sample cross beam. Obtaining the physical property parameters of the target position in the sample restraint member under the action of a force includes:

[0027] Collecting the physical property parameters of the target position under different extrusion forces through a physical property tester;

[0028] Wherein, if the physical property tester includes a magnetic parameter tester, the physical property parameters include magnetic parameters; if the physical property tester includes a mechanical parameter tester, the physical property parameters include mechanical parameters.

[0029] In this embodiment, a physical property tester is used to collect the physical property parameters of the target position under different extrusion pressures, thereby providing a basis for constructing a force model based on the physical property parameters under different extrusion pressures.

[0030] In one embodiment, a physical property tester is used to collect the physical property parameters of the target position under different extrusion pressures, including:

[0031] When gas that causes the large surface of the dummy battery cell to bulge is filled into the dummy battery cell disposed on one side of the sample fixture, and the dummy battery cell is extruded by an extruder with different extrusion pressures, a physical property tester is used to collect the physical property parameters of the target position under different extrusion pressures; wherein, the dummy battery cell is a battery cell without electrolyte injected.

[0032] In this embodiment, by filling gas that causes the large surface of the dummy battery cell disposed on one side of the sample fixture to bulge into the dummy battery cell, and the extruder extrudes the dummy battery cell with different extrusion pressures to apply the extrusion pressure to the end plate or the crossbeam, which is equivalent to when the battery undergoes real expansion, so that the expansion force when the battery undergoes real expansion acting on the end plate or the crossbeam can be simulated, and a physical property tester is used to collect the physical property parameters of the target position under different extrusion pressures. Furthermore, a force model is constructed based on the physical property parameters under different extrusion pressures, so that the force in the obtained force model can more realistically reflect the actual expansion force of the battery.

[0033] In one embodiment, the method further includes:

[0034] Obtain the target pressure of the verification battery under a preset number of cycle turns through a pressure sensor disposed in the verification battery;

[0035] According to the force model corresponding to the physical property parameter type of the sample restraint member matched with the external restraint member of the verification battery and the second physical property parameter at the second preset position of the external restraint member of the verification battery under the preset number of cycle turns, determine the force under the second physical property parameter under the preset number of cycle turns; the parameter type of the second physical property parameter is the same as the physical property parameter type, and the second preset position matches the target position;

[0036] Determine the test accuracy of the force model under the preset number of cycle turns according to the force corresponding to the preset number of cycle turns and the target pressure.

[0037] In this embodiment, by means of the pressure sensor disposed in the verification battery, the target pressure of the verification battery under a preset number of cycles is obtained. According to the force model corresponding to the physical property parameter type of the sample restraint member matched with the external restraint member of the verification battery and the second physical property parameter at the second preset position of the external restraint member of the verification battery under the preset number of cycles, the force under the second physical property parameter under the preset number of cycles is determined. Furthermore, according to the force corresponding to the preset number of cycles and the target pressure, the test accuracy of the force model under the preset number of cycles is determined, so that the accuracy of the expansion force test result of the battery to be tested obtained by the force model provided in this embodiment can be verified, which can more accurately reflect the actual expansion force of the battery to be tested after it is returned to the factory, and reduce the difference between the expansion force test result of the battery to be tested obtained and the actual expansion force of the battery to be tested.

[0038] In one embodiment, determining the test accuracy of the force model under the preset number of cycles according to the force corresponding to the preset number of cycles and the target pressure includes:

[0039] Determining the difference between the force corresponding to the preset number of cycles and the target pressure;

[0040] According to the difference and the force corresponding to the preset number of cycles, determining the test accuracy of the force model under the preset number of cycles.

[0041] In this embodiment, by determining the difference between the force corresponding to the preset number of cycles and the target pressure, determining the quotient obtained by dividing the difference by the force corresponding to the preset number of cycles, and determining the test accuracy of the force model under the preset number of cycles according to the quotient, the accuracy of the expansion force test result of the battery to be tested obtained by the force model provided in this embodiment can be verified, which can more accurately reflect the actual expansion force of the battery to be tested after it is returned to the factory, and reduce the difference between the expansion force test result of the battery to be tested obtained and the actual expansion force of the battery to be tested.

[0042] In one embodiment, the number of pressure sensors is multiple. By means of the pressure sensors disposed in the verification battery, obtaining the target pressure of the verification battery under the preset number of cycles includes:

[0043] Under the preset number of cycles, obtaining the pressures of the verification battery detected by each pressure sensor;

[0044] According to the pressures of the verification battery detected by each pressure sensor, determining the target pressure of the verification battery under the preset number of cycles.

[0045] In this embodiment, by obtaining the pressure of the verification battery detected by each pressure sensor under a preset number of circulation cycles, and determining the target pressure of the verification battery under the preset number of circulation cycles according to the pressure of the verification battery detected by each pressure sensor, the accuracy of the obtained target pressure is improved, and the test accuracy of the force model is verified more accurately.

[0046] In one embodiment, the method further includes:

[0047] If the first physical characteristic parameter is outside the range of the physical characteristic parameters characterized by the force model corresponding to the physical characteristic parameter type, it is determined that there is an abnormality in the restraint outside the battery to be tested.

[0048] In this embodiment, if the first physical characteristic parameter is outside the range of the physical characteristic parameters characterized by the force model corresponding to the physical characteristic parameter type, it is determined that there is an abnormality in the restraint outside the battery to be tested, so as to assist in the structural design of the components of the battery, reduce the probability of product failure due to design defects or the probability of design redundancy, and thus reduce the cost.

[0049] In a second aspect, the present application also provides a battery expansion force test device. The device includes:

[0050] A first acquisition module, configured to acquire a first physical characteristic parameter at a first preset position of a restraint outside the battery to be tested;

[0051] A first determination module, configured to determine the force of the battery to be tested under the first physical characteristic parameter according to the first physical characteristic parameter and the force model corresponding to the sample restraint that matches the restraint; the force model is used to characterize the corresponding relationship between the force applied to the target position in the sample restraint and the physical characteristic parameter, the force model includes the force model corresponding to the physical characteristic parameter type of the sample restraint, the first preset position matches the target position, and the physical characteristic parameter type is the same as the parameter type of the first physical characteristic parameter;

[0052] A second determination module, configured to determine the expansion force test result of the battery to be tested according to the force under the first physical characteristic parameter.

[0053] In a third aspect, the present application also provides a computer device. The computer device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the steps of any of the above methods are implemented.

[0054] In a fourth aspect, the present application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of any of the above methods are implemented.

[0055] Fifth aspect, the present application also provides a computer program product. The computer program product includes a computer program which, when executed by a processor, implements the steps of any of the above methods.

[0056] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following specifically illustrates the specific embodiments of the present application. Description of the Drawings

[0057] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. Moreover, in all the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0058] Figure 1 is a schematic internal structure diagram of a computer device provided by an embodiment of the present application;

[0059] Figure 2 is one of the schematic flowcharts of the battery expansion force test method provided by an embodiment of the present application;

[0060] Figure 3 is a schematic diagram of a force model provided by an embodiment of the present application;

[0061] Figure 4 is another schematic diagram of a force model provided by an embodiment of the present application;

[0062] Figure 5 is a schematic flowchart of a method for constructing a force model provided by an embodiment of the present application;

[0063] Figure 6 is a schematic flowchart of a method for determining the test accuracy of a force model provided by an embodiment of the present application;

[0064] Figure 7 is another schematic flowchart of a method for determining the test accuracy of a force model provided by an embodiment of the present application;

[0065] Figure 8 is a schematic flowchart of a method for obtaining a target pressure provided by an embodiment of the present application;

[0066] Figure 9 is the second schematic flowchart of the battery expansion force test method provided by an embodiment of the present application;

[0067] Figure 10 is the third schematic flowchart of the battery expansion force test method provided by an embodiment of the present application;

[0068] Figure 11 is a structural block diagram of a battery expansion force testing device provided by an embodiment of the present application;

[0069] Figure 12 is a structural block diagram of a device for constructing a force model provided by an embodiment of the present application;

[0070] Figure 13 is a structural block diagram of a device for determining test accuracy provided by an embodiment of the present application. Detailed implementation manners

[0071] The embodiments of the technical solution of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, so they are only examples and cannot be used to limit the protection scope of the present application.

[0072] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above accompanying drawing descriptions are intended to cover non-exclusive inclusion.

[0073] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality" is more than two unless otherwise specifically defined.

[0074] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments may be included in at least one embodiment of the present application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

[0075] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the front and back associated objects.

[0076] In the description of the embodiments of the present application, the term "plurality" means two or more (including two). Similarly, "multiple groups" means two or more groups (including two groups), and "multiple pieces" means two or more pieces (including two pieces).

[0077] The swelling force test of the returned battery is crucial for the reliability of product design. For example, based on the measured swelling force, parameters of the battery cells in the battery can be designed, and the strength of the end plates or steel strips that restrain the battery can be determined. Among them, the battery may include a battery module or a battery pack. A battery module refers to a module composed of multiple battery cells, and a battery pack refers to a battery pack composed of multiple battery modules.

[0078] Currently, after the battery is returned to the factory, the returned battery is disassembled, and a mechanical sensor is implanted into the battery, and the swelling force inside the battery is measured through the mechanical sensor. However, there is usually a large swelling force inside the returned battery, the battery cells undergo irreversible swelling, and the internal components of the battery are deformed after disassembly, resulting in the state of the battery after the mechanical sensor is implanted not being the same as the state before the battery is disassembled. Therefore, this method has the problem that there is a large difference between the measured swelling force and the actual swelling force inside the battery when it is returned to the factory.

[0079] Since gas generation and expansion of the electrode plates in the battery cells during continuous use cause the swelling force of the battery to increase continuously, the outside of the battery is usually restrained by end plates, crossbeams or steel strips. Under the continuous action of the swelling force, these restraining components outside the battery usually undergo irreversible plastic deformation. After the plastic deformation occurs, the microscopic crystal structure inside the restraining component changes significantly, and a large number of defects are generated inside. The generation of defects will cause significant changes in the physical properties of the material of the restraining component itself, such as significant changes in electrical parameters, magnetic parameters, mechanical parameters, etc. Therefore, based on the principle that the swelling force causes significant changes in the physical properties of the material of the restraining component itself, the embodiments of the present application provide a method for testing the swelling force of a battery. By measuring the physical property parameters of the restraining component to determine the swelling force received by the restraining component, the difference between the measured swelling force and the actual swelling force inside the battery when it is returned to the factory can be reduced, and the obtained swelling force test result is closer to the actual swelling force inside the battery when it is returned to the factory, and the battery does not need to be disassembled, realizing non-destructive detection of the swelling force.

[0080] This method for testing the swelling force of a battery can be applied to, for example Figure 1The computer device shown can be a terminal. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements a method for testing the expansion force of a battery. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, a trackball, or a touchpad provided on the housing of the computer device, or an external keyboard, touchpad, or mouse, etc.

[0081] Those skilled in the art can understand that Figure 1 the structure shown in is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have a different component layout.

[0082] As Figure 2 shown, Figure 2 is one of the schematic flowcharts of the method for testing the expansion force of a battery provided by an embodiment of this application. Taking the application of this method to the Figure 1 computer device in as an example for description, it includes the following steps S201 - S203:

[0083] S201, obtain the first physical property parameter at the first preset position of the restraint member outside the battery to be tested.

[0084] The battery to be tested may include a battery module or a battery pack returned to the factory. Among them, the battery module includes multiple battery cells. The battery cells are usually in the shape of a cuboid. The large surfaces of the multiple battery cells are arranged parallel and closely to make their positive and negative directions consistent. At least one of the binding members such as steel belts, end plates, and crossbeams is used to bind the multiple battery cells to form a battery module. For the cuboid-shaped battery to be tested, the battery to be tested includes two ends in the first direction and two ends in the second direction. The first direction and the second direction are directions perpendicular to the thickness direction of the tabs of the battery to be tested. The length of the battery to be tested in the first direction is greater than the length of the battery to be tested in the second direction. The steel belt usually winds around the multiple battery cells in a circle along the first direction and the second direction to bind the multiple battery cells. The end plates and crossbeams are usually located at the two ends of the battery to be tested in the first direction, that is, an end plate or a crossbeam is arranged at the end where the large surfaces of the battery cells are located at both ends of the battery to be tested to bind the multiple battery cells.

[0085] The first preset position may be the middle position of the binding member located at the target end of the battery to be tested. If the binding member is a steel belt, the first preset position may be the middle position of the steel belt at at least one of the two ends of the battery to be tested in the second direction; if the binding member is an end plate or a crossbeam, the first preset position may be the middle position of the end plate or the crossbeam at at least one of the two ends of the battery to be tested in the first direction. The first preset position can be detected by a physical property tester to obtain the first physical property parameter.

[0086] In a possible implementation, taking the battery to be tested as a battery module and the binding member as a steel belt as an example, under the continuous action of the expansion force of the battery cells, the steel belt outside the battery module usually undergoes irreversible plastic deformation. After the plastic deformation occurs, the microscopic crystal structure inside the steel belt changes significantly, and a large number of defects are generated inside. The generation of defects will cause changes in the physical properties of the material of the steel belt itself, such as significant changes in electrical parameters and mechanical parameters. Therefore, the electrical parameters and / or mechanical parameters at the first preset position of the steel belt can be obtained. Among them, the electrical parameters may include conductivity, resistivity, etc., and the mechanical parameters may include hardness, strength, etc. The first preset position may be the middle position outside the steel belt at the two ends of the battery module in the second direction. The length of the middle position may be a preset length, for example, 1 centimeter. For a cuboid-shaped battery module, if the two ends of the battery module in the second direction are end A and end B, the first physical property parameter of the middle position of the steel belt at end A and / or the first physical property parameter of the middle position of the steel belt at end B can be obtained.

[0087] In another possible implementation, taking the battery under test as a battery module and the restraint as an end plate as an example, under the continuous action of the expansion force of the battery cells, the end plate outside the battery module usually undergoes irreversible plastic deformation. After the plastic deformation occurs, the microscopic crystal structure inside the end plate changes significantly, and a large number of defects are generated inside. The generation of defects will cause changes in the physical properties of the material of the end plate itself, such as significant changes in magnetic parameters and mechanical parameters. Therefore, at least one first physical property parameter among the magnetic parameter and the mechanical parameter at the first preset position of the end plate can be obtained. Among them, the magnetic parameter can include magnetic permeability, magnetic susceptibility, etc., and the mechanical parameter can include hardness, strength, etc. The first preset position can be the middle position of the end plate at at least one end of the two ends of the battery module in the first direction. For a battery module in the shape of a cuboid, if the two ends of the battery module in the first direction are the C end and the D end, then the first physical property parameter at the middle position of the end plate at the C end and / or the first physical property parameter at the middle position of the end plate at the D end can be obtained.

[0088] In yet another possible implementation, taking the battery under test as a battery module and the restraint as a crossbeam as an example, under the continuous action of the expansion force of the battery cells, the crossbeam outside the battery module usually undergoes irreversible plastic deformation. After the plastic deformation occurs, the microscopic crystal structure inside the crossbeam changes significantly, and a large number of defects are generated inside. The generation of defects will cause changes in the physical properties of the material of the crossbeam itself, such as significant changes in magnetic parameters and mechanical parameters. Therefore, at least one first physical property parameter among the magnetic parameter and the mechanical parameter at the first preset position of the crossbeam can be obtained. Among them, the magnetic parameter can include magnetic permeability, magnetic susceptibility, etc., and the mechanical parameter can include hardness, strength, etc. The first preset position can be the middle position of the crossbeam at both ends of the battery module. For a battery module in the shape of a cuboid, if the two ends of the battery module in the first direction are the C end and the D end, then the first physical property parameter at the middle position of the crossbeam at the C end and / or the first physical property parameter at the middle position of the crossbeam at the D end can be obtained.

[0089] When the battery under test is a battery pack, obtaining the first physical property parameter at the first preset position of the restraint outside the battery under test is similar to the above-mentioned obtaining of the first physical property parameter at the first preset position of the restraint outside the battery module, and will not be elaborated here.

[0090] S202. Determine the acting force of the battery under test under the first physical property parameter according to the first physical property parameter and the acting force model corresponding to the sample restraint that matches the restraint.

[0091] Among them, the force model is used to characterize the corresponding relationship between the force applied to the target position in the sample restraint and the physical property parameters. The force model includes the force model corresponding to the type of physical property parameters of the sample restraint. The first preset position matches the target position, and the type of physical property parameters is the same as the parameter type of the first physical property parameter. The target position in the sample restraint can be the middle position of the sample restraint. The sample restraint that matches the restraint means that the material of the restraint of the battery to be tested is the same as that of the sample restraint. That is, if the restraint is a steel strip, the sample restraint is a sample steel strip; if the restraint is an end plate, the sample restraint is a sample end plate; if the restraint is a crossbeam, the sample restraint is a sample crossbeam.

[0092] The type of physical property parameters of the sample restraint refers to the parameter type of the physical property parameters of the sample restraint. Exemplarily, the type of physical property parameters of the sample restraint that matches the restraint being the same as the parameter type of the first physical property parameter of the restraint means that: if the first physical property parameter of the steel strip is the conductivity parameter type, then the type of physical property parameters of the sample steel strip is the conductivity parameter type. The force model in this step refers to the force model corresponding to the conductivity parameter type of the sample steel strip, that is, the tensile force conductivity model corresponding to the sample steel strip; if the first physical property parameter of the end plate is the magnetic susceptibility parameter type, then the type of physical property parameters of the sample end plate is the magnetic susceptibility parameter type. The force model in this step refers to the force model corresponding to the magnetic susceptibility parameter type of the sample end plate, that is, the extrusion force magnetic susceptibility model corresponding to the sample end plate.

[0093] If the first physical property parameter is the conductivity of the steel strip, the force model in this step is used to characterize the corresponding relationship between the force at the target position in the sample steel strip and the conductivity; if the first physical property parameter is the hardness of the steel strip, the force model in this step is used to characterize the corresponding relationship between the force at the target position in the sample steel strip and the hardness; if the first physical property parameter is the magnetic susceptibility of the end plate, the force model in this step is used to characterize the corresponding relationship between the force at the target position in the sample end plate and the magnetic susceptibility; if the first physical property parameter is the magnetic susceptibility of the crossbeam, the force model in this step is used to characterize the corresponding relationship between the force at the target position in the sample crossbeam and the magnetic susceptibility.

[0094] Exemplarily, if the restraint in S201 is a steel strip and the first physical property parameter is conductivity, the force model corresponding to the parameter type of the first physical property parameter is as Figure 3 shown in the model, that is, the tensile force conductivity model, Figure 3It is a schematic diagram of a force model provided by an embodiment of the present application. This force model is constructed based on the correspondence between the tensile force and the conductivity at the target position in the sample steel strip. This force model is used to characterize the correspondence between the force applied to the target position in the sample steel strip and the conductivity. The parameter types of the physical property parameters in this force model and the first physical property parameter are both conductivity parameter types, and the force in this force model refers to the tensile force. The target position in the sample steel strip is the middle position of the sample steel strip, and the first preset position is the middle position outside the steel strip on the side of the battery module. Therefore, the target position in the sample steel strip matches the first preset position, both referring to the middle position of the steel strip. Based on Figure 3 The tensile force at this conductivity can be determined based on the shown tensile force - conductivity model and the conductivity at the middle position of the steel strip outside the battery to be tested. If the conductivity 1 at the middle position of the steel strip on the first side of the battery to be tested is determined in S201, then the tensile force 1 corresponding to the conductivity 1 can be determined in this step. If the conductivity 2 at the middle position of the steel strip on the second side of the battery to be tested is determined in S201, then the tensile force 2 corresponding to the conductivity 2 can be determined in this step. If the conductivity 1 and the conductivity 2 are determined in S201, then the tensile force 1 corresponding to the conductivity 1 and the tensile force 2 corresponding to the conductivity 2 can be determined in this step.

[0095] Exemplarily, if the restraint in S201 is an end plate and the first physical property parameter is the magnetic permeability, then the force model corresponding to the parameter type of the first physical property parameter is as Figure 4 the shown model, that is, the extrusion force - magnetic permeability model. Figure 4 It is another schematic diagram of a force model provided by an embodiment of the present application. This force model is used to characterize the correspondence between the force applied to the target position in the sample end plate and the magnetic permeability. The parameter types of the physical property parameters in this force model and the first physical property parameter are both magnetic permeability parameter types, and the force in this force model refers to the extrusion force. The target position in the sample end plate is the middle position of the sample end plate, and the first preset position is the middle position outside the end plate at one end of the battery module, which matches the first preset position of the end plate outside the battery to be tested, that is, both refer to the middle position of the end plate. Based on Figure 4 The extrusion force at this magnetic permeability can be determined based on the shown extrusion force - magnetic permeability model and the magnetic permeability at the middle position of the end plate outside the battery to be tested. If the magnetic permeability 1 at the middle position of the end plate at the first end of the battery to be tested is determined in S201, then the extrusion force 1 corresponding to the magnetic permeability 1 can be determined in this step. If the magnetic permeability 2 at the middle position of the end plate at the second end of the battery to be tested is determined in S201, then the extrusion force 2 corresponding to the magnetic permeability 2 can be determined in this step. If the magnetic permeability 1 and the magnetic permeability 2 are determined in S201, then the extrusion force 1 corresponding to the magnetic permeability 1 and the extrusion force 2 corresponding to the magnetic permeability 2 can be determined in this step.

[0096] S203. Determine the expansion force test result of the battery to be tested according to the acting force under the first physical characteristic parameter.

[0097] The acting force under the first physical characteristic parameter can be used as the expansion force test result of the battery to be tested. Or the product of the acting force under the first physical characteristic parameter multiplied by a preset coefficient can be used as the expansion force test result of the battery to be tested.

[0098] Exemplarily, if the conductivity 1 at the middle position of the steel strip on the first side of the battery to be tested is determined in S201, and the tensile force 1 corresponding to the conductivity 1 is determined in S202, then the tensile force 1 can be used as the expansion force test result of the battery to be tested in this step.

[0099] If the conductivity 2 at the middle position of the steel strip on the second side of the battery to be tested is determined in S201, and the tensile force 2 corresponding to the conductivity 2 is determined in S202, then the tensile force 2 can be used as the expansion force test result of the battery to be tested in this step.

[0100] If the conductivity 1 and the conductivity 2 are determined in S201, and the tensile force 1 corresponding to the conductivity 1 and the tensile force 2 corresponding to the conductivity 2 are determined in S202, then the tensile force 1 and the tensile force 2 can be used as the expansion force test result of the battery to be tested in this step.

[0101] The battery expansion force test method provided in this embodiment obtains the first physical characteristic parameter at the first preset position of the restraint outside the battery to be tested, determines the acting force of the battery to be tested under the first physical characteristic parameter according to the first physical characteristic parameter and the acting force model corresponding to the sample restraint that matches the restraint, and then determines the expansion force test result of the battery to be tested according to the acting force under the first physical characteristic parameter, so as to realize non-destructive detection of the expansion force of the battery to be tested without disassembling the battery to be tested, so that the obtained expansion force test result can more accurately reflect the actual expansion force inside the battery when it returns to the factory, and reduces the difference between the expansion force test result and the actual expansion force inside the battery when it returns to the factory.

[0102] In one embodiment, the first physical characteristic parameter includes at least one of electrical parameter, magnetic parameter, and mechanical parameter:

[0103] The first physical characteristic parameter can be obtained by detecting the first preset position with a physical characteristic tester set at the preset test position.

[0104] In a possible implementation, the electrical property tester disposed at the first preset position on the steel strip detects the first preset position to obtain electrical properties; wherein, the physical property tester includes an electrical property tester, the preset test position is the first preset position, and the first physical property parameter includes electrical properties. The electrical property tester can be attached to the middle positions of the steel strips at both ends in the second direction of the battery to be tested, so as to obtain the electrical properties of the middle positions of the steel strips. The electrical property tester can include a conductivity tester and a resistivity tester.

[0105] In another possible implementation, the magnetic property tester disposed at the preset test position detects the first preset position to obtain magnetic properties; the physical property tester includes a magnetic property tester, the preset test position is a position whose distance from the first preset position in the target direction is equal to the preset distance, the target direction is the direction perpendicular to the large surface of the battery cell in the battery to be tested, and the first physical property parameter includes magnetic properties. Among them, the preset distance is, for example, 10 cm, and the magnetic property tester can include a magnetic susceptibility tester and a magnetic permeability tester.

[0106] In this embodiment, the first physical property parameter includes at least one of electrical properties, magnetic properties, and mechanical properties, so as to obtain the expansion force test results under diverse physical property parameters and the corresponding force models, and provide more abundant and diverse analysis data for analyzing the expansion force of the battery.

[0107] In one embodiment, the restraint member includes a steel strip, and the first physical property parameter includes electrical properties, and the electrical properties are the electrical properties obtained by the electrical property tester detecting the first preset position.

[0108] In this embodiment, when the restraint member is a steel plate, by obtaining the electrical properties of the steel strip and the corresponding force model, the expansion force test result of the battery to be tested is determined, and non-destructive detection of the expansion force of the battery is realized without disassembling the structure of the battery.

[0109] In one embodiment, the restraint member includes an end plate and / or a cross beam, and the first physical property parameter includes magnetic properties, and the magnetic properties are the magnetic properties obtained by the magnetic property tester detecting the first preset position.

[0110] The magnetic property tester disposed at the preset test position can detect the first preset position to obtain magnetic properties; the physical property tester includes a magnetic property tester, the preset test position is a position whose distance from the first preset position in the target direction is equal to the preset distance, the target direction is the direction perpendicular to the large surface of the battery cell in the battery to be tested, and the first physical property parameter includes magnetic properties.

[0111] In this embodiment, when the restraint member is an end plate and / or a cross beam, by obtaining the magnetic parameters of the end plate and / or the cross beam and the corresponding force model, the expansion force test result of the battery to be tested is determined, realizing non-destructive detection of the expansion force of the battery without disassembling the battery structure.

[0112] In one embodiment, the restraint member includes at least one of a steel strip, an end plate, and a cross beam, and the first physical property parameter includes a mechanical parameter, and the mechanical parameter is obtained by detecting a first preset position with a mechanical parameter tester.

[0113] The mechanical parameter is obtained by detecting the first preset position with a mechanical parameter tester pressed on the first preset position; the physical property tester includes a mechanical parameter tester, the preset test position is the first preset position, and the first physical property parameter includes a mechanical parameter.

[0114] In this embodiment, when the restraint member includes at least one of a steel strip, an end plate, and a cross beam, by obtaining the mechanical parameter of the restraint member and the corresponding force model, the expansion force test result of the battery to be tested is determined, realizing non-destructive detection of the expansion force of the battery without disassembling the battery structure.

[0115] In one embodiment, as Figure 5 shown, Figure 5 is a schematic flowchart of a method for constructing a force model provided by an embodiment of the present application, and the method may include the following steps S501-S502:

[0116] S501, obtain the physical property parameters of the target position in the sample restraint member under the action of a force.

[0117] If the sample restraint member is a sample steel strip, the electrical property parameter or mechanical parameter of the target position in the sample steel strip under the tensile force can be obtained.

[0118] If the sample restraint member includes a sample fixing member, and the sample fixing member includes at least one of a sample end plate and a sample cross beam, the magnetic parameter or mechanical parameter of the target position in the sample fixing member under the extrusion force can be obtained.

[0119] S502, construct a force model according to the force and the physical property parameters under the action of the force.

[0120] If the sample restraint member is a sample steel strip and the conductivity of the target position in the sample steel strip under the tensile force is obtained in S501, a tensile force conductivity model can be established in this step. The tensile force conductivity model can represent the corresponding relationship between the tensile force and the conductivity, and the force model includes the tensile force conductivity model. The tensile force conductivity model is the force model corresponding to the conductivity parameter type of the sample steel strip.

[0121] If the sample restraint is a sample steel strip and the hardness at the target position in the sample steel strip under the tensile force is obtained in S501, then in this step, a tensile force-hardness model can be established. This tensile force-hardness model can characterize the corresponding relationship between the tensile force and the hardness. The force model includes the tensile force-hardness model. The tensile force-hardness model is the force model corresponding to the hardness parameter type of the sample steel strip.

[0122] In this embodiment, by obtaining the physical property parameters of the target position in the sample restraint under the acting force, and based on the acting force and the physical property parameters under the acting force, a force model is constructed, so as to provide a basis for determining the acting force of the battery under test at the first physical property parameter according to the first physical property parameter and the force model corresponding to the parameter type of the pre-constructed first physical property parameter.

[0123] In one embodiment, the sample restraint includes a sample steel strip. For the above S501, obtaining the physical property parameters of the target position in the sample restraint under the acting force can be achieved in the following manner:

[0124] Collect the physical property parameters of the target position under different tensile forces through a physical property tester;

[0125] Among them, if the physical property tester includes an electrical parameter tester, the physical property parameters include electrical parameters; if the physical property tester includes a mechanical parameter tester, the physical property parameters include mechanical parameters.

[0126] A conductivity tester can be attached to the middle position of the sample steel strip, and the conductivity tester is turned on to collect the conductivity of the middle position of the sample steel strip under different tensile forces, and then a tensile force-conductivity model is constructed according to the different tensile forces and the conductivity of the middle position of the sample steel strip under the tensile force. Or, a hardness tester is pressed on the middle position of the sample steel strip, and the hardness tester is turned on to collect the hardness of the middle position of the sample steel strip under different tensile forces, and then a tensile force-hardness model is constructed according to the different tensile forces and the hardness of the middle position of the sample steel strip under the tensile force.

[0127] In this embodiment, the physical property parameters of the target position under different tensile forces are collected through a physical property tester, so as to provide a basis for constructing a force model for characterizing the corresponding relationship between the tensile force and the physical property parameters.

[0128] In one embodiment, the sample restraint includes a sample fixture, and the sample fixture includes at least one of a sample end plate and a sample cross beam. For the above S501, obtaining the physical property parameters of the target position in the sample restraint under the acting force can be achieved in the following manner:

[0129] Collect the physical property parameters of the target position under different extrusion pressures by a physical property tester; wherein, if the physical property tester includes a magnetic parameter tester, the physical property parameters include magnetic parameters, and if the physical property tester includes a mechanical parameter tester, the physical property parameters include mechanical parameters.

[0130] For the magnetic parameter tester, the magnetic parameter tester can be set at a position where the distance from the target position in the target direction is equal to the preset distance, so as to obtain the magnetic parameters of the target position of the sample fixture under different extrusion pressures, wherein the target direction is the direction perpendicular to the surface of the sample fixture. The extrusion pressure can be directly applied to the sample fixture or indirectly applied to the sample fixture. For example, an uncharged electrolyte cell is set on one side of the end plate, and a gas that causes the large surface of the cell to bulge is filled into the cell, and then the cell is extruded by an extruder with different extrusion pressures to apply the extrusion pressure to the end plate, which is equivalent to the actual expansion of the battery, and the magnetic parameters under different extrusion pressures are recorded, and then the extrusion pressure magnetic parameter model is constructed according to the magnetic parameters under different extrusion pressures.

[0131] It should be noted that the extrusion pressure magnetic parameter model corresponding to the sample fixture being the end plate is different from the extrusion pressure magnetic parameter model corresponding to the sample fixture being the crossbeam. Therefore, if the restraint outside the battery to be tested is the end plate and the first physical property parameter obtained is the magnetic susceptibility of the end plate, the extrusion pressure at this magnetic susceptibility is determined according to this magnetic susceptibility and the extrusion pressure magnetic susceptibility model corresponding to the end plate. If the restraint outside the battery to be tested is the end plate and the first physical property parameter obtained is the magnetic permeability of the end plate, the extrusion pressure at this magnetic permeability is determined according to this magnetic permeability and the extrusion pressure magnetic permeability model corresponding to the end plate. If the restraint outside the battery to be tested is the crossbeam and the first physical property parameter obtained is the magnetic susceptibility of the crossbeam, the extrusion pressure at this magnetic susceptibility is determined according to this magnetic susceptibility and the extrusion pressure magnetic susceptibility model corresponding to the crossbeam.

[0132] For a mechanical parameter tester, the mechanical parameter tester can be pressed at the middle position of the sample fixture, and the mechanical parameter tester is turned on to collect the mechanical parameters of the middle position of the sample fixture under different extrusion pressures. Then, according to different extrusion pressures and the mechanical parameters of the middle position of the sample fixture under the extrusion pressure, an extrusion pressure mechanical parameter model is constructed. It should be noted that the extrusion pressure mechanical parameter model corresponding to the sample fixture being an end plate is different from the extrusion pressure mechanical parameter model corresponding to the sample fixture being a crossbeam. Therefore, if the restraint outside the battery to be tested is an end plate and the first physical characteristic parameter obtained is the hardness of the end plate, the extrusion pressure at this hardness is determined according to this hardness and the extrusion pressure hardness model corresponding to the end plate. If the restraint outside the battery to be tested is a crossbeam and the first physical characteristic parameter obtained is the hardness of the crossbeam, the extrusion pressure at this hardness is determined according to this hardness and the extrusion pressure hardness model corresponding to the crossbeam.

[0133] In this embodiment, the physical property tester is used to collect the physical property parameters of the target position under different extrusion pressures, thereby providing a basis for constructing a force model based on the physical property parameters under different extrusion pressures.

[0134] In one embodiment, the above-mentioned collection of the physical property parameters of the target position under different extrusion pressures by the physical property tester can be achieved in the following manner:

[0135] When a gas that causes the large surface of the dummy battery cell to bulge is filled into the dummy battery cell arranged on one side of the sample fixture, and the dummy battery cell is extruded by an extruder with different extrusion pressures, the physical property tester is used to collect the physical property parameters of the target position under different extrusion pressures; wherein, the dummy battery cell is a battery cell without electrolyte injected.

[0136] In this embodiment, by filling a gas that causes the large surface of the dummy battery cell arranged on one side of the sample fixture to bulge, and the extruder extrudes the dummy battery cell with different extrusion pressures to apply the extrusion pressure to the end plate or the crossbeam, which is equivalent to when the battery undergoes real expansion. Thus, it can simulate the expansion force acting on the end plate or the crossbeam when the battery undergoes real expansion, and the physical property tester is used to collect the physical property parameters of the target position under different extrusion pressures. Then, based on the physical property parameters under different extrusion pressures, a force model is constructed, so that the force in the obtained force model can more truly reflect the actual expansion force of the battery.

[0137] In one embodiment, in one embodiment, as Figure 6 shown, Figure 6 FIG. is a schematic flowchart of a method for determining the test accuracy of a force model provided by an embodiment of the present application. The method may include the following steps S601 - S603:

[0138] S601. Obtain the target pressure of the verification battery at a preset number of cycles through a pressure sensor disposed in the verification battery.

[0139] It is possible to produce a verification battery with a pre-implanted pressure sensor inside. Through the pressure sensor disposed in the verification battery, obtain the target pressure of the verification battery at a preset number of cycles. The number of pre-implanted pressure sensors can be at least one. Exemplarily, the preset number of cycles can be 500, 1000, 3000, 6000, and the pressure of the internal pressure sensor can be recorded after each preset number of cycles.

[0140] If the number of pressure sensors is one, the pressure of this pressure sensor can be used as the target pressure at the preset number of cycles. For example, when the preset number of cycles is 500, the pressure of the pressure sensor after 500 cycles is used as the target pressure at this number of cycles.

[0141] If the number of pressure sensors is greater than two, the maximum value and / or minimum value of the pressures of multiple pressure sensors can be filtered out to obtain the remaining pressures, and the target pressure at the preset number of cycles is determined based on the remaining pressures. For example, if the number of pressure sensors is 5, the maximum value and minimum value among the 5 pressures can be filtered out, and the average value of the remaining 3 pressures is used as the target pressure at the preset number of cycles. Or, the median of the remaining 3 pressures is used as the target pressure at the preset number of cycles.

[0142] If the number of pressure sensors is equal to two, the average value of the pressures of these two pressure sensors can be used as the target pressure at the preset number of cycles.

[0143] S602. Determine the acting force at the second physical property parameter at the preset number of cycles according to the acting force model corresponding to the physical property parameter type of the sample restraint member matched with the external restraint member of the verification battery and the second physical property parameter at the second preset position of the external restraint member of the verification battery at the preset number of cycles.

[0144] Among them, the parameter type of the second physical property parameter is the same as the physical property parameter type, and the second preset position matches the target position.

[0145] The parameter type of the second physical property parameter being the same as the physical property parameter type of the sample restraint member means that if the physical property parameter type of the sample restraint member is the conductivity parameter type, then the parameter type of the second physical property parameter is also the conductivity parameter type; if the physical property parameter type of the sample restraint member is the magnetic susceptibility parameter type, then the parameter type of the second physical property parameter is also the magnetic susceptibility parameter type; if the physical property parameter type of the sample restraint member is the hardness parameter type, then the parameter type of the second physical property parameter is also the hardness parameter type.

[0146] The sample restraint for verifying the matching of the external restraint of the battery means verifying that the material of the restraint outside the battery is the same as that of the sample restraint. For example, if the sample restraint is a sample steel strip, then it is verified that the restraint outside the battery is also a steel strip.

[0147] The second preset position matches the target position, which means that the target position is the middle position of the sample restraint, and the second preset position also refers to the middle position of the restraint at the target end of the battery to be verified. For example, if the sample restraint is a sample steel strip, then the second preset position refers to the middle position of at least one of the steel strips at both ends in the second direction of the battery to be verified. If the sample restraint is a sample end plate, then the second preset position refers to the middle position of at least one of the end plates at both ends in the first direction of the battery to be verified. Among them, the battery to be verified includes two ends in the first direction and two ends in the second direction, and the first direction and the second direction are directions perpendicular to the thickness direction of the tab of the battery to be verified, and the length of the battery to be verified in the first direction is greater than the length of the battery to be verified in the second direction.

[0148] Exemplarily, if the second physical characteristic parameter is the conductivity of the steel strip outside the battery to be verified at 500 cycle turns, then the force model in this step is the tensile force conductivity model corresponding to the conductivity parameter type of the sample steel strip. Based on this tensile force conductivity model, the tensile force at the conductivity of the steel strip outside the battery to be verified at 500 cycle turns can be determined.

[0149] Another exemplarily, if the second physical characteristic parameter is the magnetic susceptibility of the end plate outside the battery to be verified at 500 cycle turns, then the force model in this step is the extrusion force magnetic susceptibility model corresponding to the magnetic susceptibility parameter type of the sample end plate. Based on this extrusion force magnetic susceptibility model, the extrusion force at the magnetic susceptibility of the end plate outside the battery to be verified at 500 cycle turns can be determined.

[0150] Another exemplarily, if the second physical characteristic parameter is the magnetic susceptibility of the cross beam outside the battery to be verified at 500 cycle turns, then the force model in this step is the extrusion force magnetic susceptibility model corresponding to the magnetic susceptibility parameter type of the sample cross beam. Based on this extrusion force magnetic susceptibility model, the extrusion force at the magnetic susceptibility of the cross beam outside the battery to be verified at 500 cycle turns can be determined.

[0151] S603. Determine the test accuracy of the force model at the preset number of cycle turns according to the force corresponding to the preset number of cycle turns and the target pressure.

[0152] In a possible implementation manner, the ratio of the target pressure corresponding to the preset number of cycle turns to the force can be determined, and the difference between this ratio and 1 is used as the test deviation of the force model at the preset number of cycle turns. Based on the test deviation at the preset number of cycle turns, the test accuracy of the force model at the preset number of cycle turns is determined.

[0153] In a possible implementation, the difference between the acting force corresponding to the preset number of circulation cycles and the target pressure can be determined, and the quotient obtained by dividing the difference by the acting force corresponding to the preset number of circulation cycles can be determined. The test deviation of the acting force model at the preset number of circulation cycles can be determined based on the quotient, and the test accuracy of the acting force model at the preset number of circulation cycles can be determined based on the test deviation at the preset number of circulation cycles.

[0154] For example, as shown in Table 1 below, taking the tensile force conductivity model of the sample steel strip in step S602 as the acting force model, it shows the conductivity of the steel strip outside the verification battery at the preset number of circulation cycles, the tensile force at the conductivity of the steel strip outside the verification battery at the preset number of circulation cycles determined based on the tensile force conductivity model, the target pressure of the verification battery at the preset number of circulation cycles obtained by the pressure sensor arranged in the verification battery, and the measurement deviation between the tensile force corresponding to the preset number of circulation cycles and the target pressure. Among them, the unit of conductivity is Siemens per meter, and the units of tensile force and target pressure are Newton.

[0155]

[0156] Table 1

[0157] Combined with the data shown in Table 1, it shows that the test deviation of the tensile force conductivity model corresponding to the sample steel strip is small. By means of the pre-constructed tensile force conductivity model corresponding to the sample steel strip and detecting the conductivity of the battery to be tested, a more accurate expansion force of the battery to be tested for returning to the factory can be obtained.

[0158] Another example, as shown in Table 2 below, taking the extrusion force conductivity model of the sample end plate in step S602 as the acting force model, it shows the magnetic permeability of the end plate outside the verification battery at the preset number of circulation cycles, based on Figure 4 the extrusion force magnetic permeability model shown, the extrusion force at the magnetic permeability of the end plate outside the verification battery at the preset number of circulation cycles, the target pressure of the verification battery at the preset number of circulation cycles obtained by the pressure sensor arranged in the verification battery, and the measurement deviation between the extrusion force corresponding to the preset number of circulation cycles and the target pressure. Among them, the unit of magnetic permeability is Henry per meter, and the units of extrusion force and target pressure are Newton.

[0159]

[0160] Table 2

[0161] Combined with the data shown in Table 2, it shows that the test deviation of the extrusion force magnetic permeability model corresponding to the sample end plate is small. Therefore, by means of the pre-constructed extrusion force magnetic permeability model corresponding to the sample end plate and detecting the magnetic permeability of the battery to be tested, a more accurate expansion force of the battery to be tested for returning to the factory can be obtained.

[0162] In this embodiment, the target pressure of the verification battery under the preset number of cycles is obtained through the pressure sensor arranged in the verification battery. According to the force model corresponding to the physical characteristic parameter type of the sample restraint member matched with the external restraint member of the verification battery and the second physical characteristic parameter at the second preset position of the external restraint member of the verification battery under the preset number of cycles, the force under the second physical characteristic parameter under the preset number of cycles is determined. Furthermore, according to the force corresponding to the preset number of cycles and the target pressure, the test accuracy of the force model under the preset number of cycles is determined, so as to verify the accuracy of the expansion force test result of the battery under test obtained by the force model provided in this embodiment, which can more accurately reflect the actual expansion force of the battery under test after it is returned to the factory, and reduce the difference between the expansion force test result of the battery under test and the actual expansion force of the battery under test.

[0163] In one embodiment, in one embodiment, as Figure 7 shown, Figure 7 FIG. is a schematic flowchart of another method for determining the test accuracy of the force model provided by the embodiment of the present application. The above S603 may include the following steps S701-S702:

[0164] S701, determine the difference between the force corresponding to the preset number of cycles and the target pressure.

[0165] S702, determine the test accuracy of the force model under the preset number of cycles according to the difference and the force corresponding to the preset number of cycles.

[0166] In one possible implementation, the quotient obtained by dividing the difference by the force corresponding to the preset number of cycles can be determined, and the product obtained by multiplying the quotient by 100% is used as the test deviation of the force model under the preset number of cycles. Based on the test deviation under the preset number of cycles, the test accuracy of the force model under the preset number of cycles is determined. Exemplarily, the quotient obtained by dividing the difference by the force corresponding to the preset number of cycles is multiplied by 100% to obtain the test deviation, and the difference between 100% and the test deviation is used as the test accuracy of the force model under the preset number of cycles.

[0167] In another possible implementation, the quotient obtained by dividing the difference by the force corresponding to the preset number of cycles can be determined, and the quotient is multiplied by 100% to obtain a product. The result obtained by multiplying the product by a preset coefficient is used as the test deviation of the force model under the preset number of cycles. Based on the test deviation under the preset number of cycles, the test accuracy of the force model under the preset number of cycles is determined.

[0168] In this embodiment, by determining the difference between the acting force corresponding to the preset number of cycles and the target pressure, determining the quotient obtained by dividing the difference by the acting force corresponding to the preset number of cycles, and determining the test accuracy of the acting force model at the preset number of cycles according to the quotient, the accuracy of the expansion force test result of the battery to be tested obtained by the acting force model provided in this embodiment can be verified, which can more accurately reflect the actual expansion force of the battery to be tested after it is returned to the factory, and reduce the difference between the expansion force test result of the battery to be tested and the actual expansion force of the battery to be tested.

[0169] In one embodiment, as Figure 8 shown, Figure 8 FIG. is a schematic flowchart of a method for obtaining a target pressure provided by an embodiment of the present application. In this embodiment, the number of pressure sensors is multiple, that is, it is verified that multiple pressure sensors are pre-implanted in the battery. The above S601 may include the following steps S801-S802:

[0170] S801, at the preset number of cycles, obtain the pressures of the verification battery detected by each pressure sensor.

[0171] S802, according to the pressures of the verification battery detected by each pressure sensor, determine the target pressure of the verification battery at the preset number of cycles.

[0172] If the number of pressure sensors is equal to two, the average value of the pressures of the two pressure sensors can be used as the target pressure at the preset number of cycles.

[0173] If the number of pressure sensors is greater than two, then the maximum value and / or minimum value of the pressures of the multiple pressure sensors can be filtered out to obtain the remaining pressures, and the target pressure at the preset number of cycles is determined based on the remaining pressures. For example, if the number of pressure sensors is 5, the maximum value and the minimum value among the 5 pressures can be filtered out, and the average value of the remaining 3 pressures can be used as the target pressure at the preset number of cycles. Or, the median of the remaining 3 pressures can be used as the target pressure at the preset number of cycles.

[0174] In this embodiment, by obtaining the pressures of the verification battery detected by each pressure sensor at the preset number of cycles and determining the target pressure of the verification battery at the preset number of cycles according to the pressures of the verification battery detected by each pressure sensor, the accuracy of the obtained target pressure is improved, and the test accuracy of the acting force model is verified more accurately.

[0175] In one embodiment, the method further includes:

[0176] If the first physical characteristic parameter is outside the interval range of the physical characteristic parameters characterized by the acting force model corresponding to the physical characteristic parameter type, it is determined that there is an abnormality in the restraint member outside the battery to be tested.

[0177] Taking the tensile force conductivity model corresponding to the conductivity parameter type of the sample steel strip as the force model as an example, if the conductivity, which is the first physical property parameter, is outside the range of the physical property parameters characterized by the tensile force conductivity model shown as Figure 3 shown, it can be determined that there is an abnormality in the steel strip outside the battery to be tested. For example, due to a crack in the steel strip outside the battery to be tested, the conductivity at the first preset position of the steel strip outside the battery to be tested obtained is outside the range of the physical property parameters characterized by the tensile force conductivity model shown as Figure 3 shown. Therefore, if the first physical property parameter is outside the range of the physical property parameters characterized by the force model corresponding to the physical property parameter type, it is determined that there is an abnormality in the restraint outside the battery to be tested. Confirm whether there are weak points and failure points in the current component.

[0178] In this embodiment, if the first physical property parameter is outside the range of the physical property parameters characterized by the force model corresponding to the physical property parameter type, it is determined that there is an abnormality in the restraint outside the battery to be tested, so as to assist in the structural design of the components of the battery, reduce the probability of product failure due to design defects or the probability of design redundancy, and thus reduce the cost.

[0179] In one embodiment, in combination with Figure 9 the overall process of the battery expansion force test method is described. Figure 9 FIG. is the second schematic flow chart of the battery expansion force test method provided by the embodiment of the present application. In this embodiment, by constructing a complete tensile force conductivity model, non-destructive testing of the expansion force of the battery to be tested can be realized, and the efficiency and accuracy of the expansion force measurement can be improved. The method includes the following steps S901-S905:

[0180] S901, obtain the conductivity of the middle position of the sample steel strip under different tensile forces.

[0181] S902, construct a tensile force conductivity model according to different tensile forces and the conductivity under the tensile forces.

[0182] S903, obtain the conductivity at the first preset position of the steel strip outside the battery to be tested.

[0183] S904, determine the tensile force of the battery to be tested at the conductivity at the first preset position according to the conductivity at the first preset position of the steel strip and the tensile force conductivity model.

[0184] S905, take the tensile force of the battery to be tested at the conductivity at the first preset position as the test result of the expansion force of the battery to be tested.

[0185] In one embodiment, in combination withFigure 10 Describe the overall process of the battery swelling force test method. Figure 10 Figure 10 is the third schematic flowchart of the battery swelling force test method provided by the embodiments of the present application. In this embodiment, by constructing a complete tensile force conductivity model, non-destructive testing of the swelling force of the battery to be tested can be achieved, improving the efficiency and accuracy of swelling force measurement. The method includes the following steps S1001 - S1005:

[0186] S1001, When filling the dummy battery set on one side of the sample end plate with gas that causes the large surface of the dummy battery to bulge, and squeezing the dummy battery with different squeezing forces through an extruder, collect the magnetic susceptibility at the target position under different squeezing forces through a physical property tester.

[0187] S1002, Construct a squeezing force - magnetic susceptibility model based on different squeezing forces and the magnetic susceptibilities under the squeezing forces.

[0188] S1003, Obtain the magnetic susceptibility at the first preset position of the end plate outside the battery to be tested.

[0189] S1004, Determine the squeezing force of the battery to be tested at the magnetic susceptibility at the first preset position of the end plate according to the magnetic susceptibility at the first preset position of the end plate and the squeezing force - magnetic susceptibility model.

[0190] S1005, Take the squeezing force of the battery to be tested at the magnetic susceptibility at the first preset position as the test result of the swelling force of the battery to be tested.

[0191] Since the swelling force test result obtained in the embodiments of the present application is relatively accurate, therefore, the swelling force test result obtained in the embodiments of the present application can be compared with the swelling force predicted by the product swelling force prediction model, so as to verify the accuracy and reliability of the product swelling force prediction model.

[0192] It should be understood that although each step in the flowchart involved in the above embodiments is shown in sequence according to the indication of the arrow, these steps are not necessarily executed in the order indicated by the arrow. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowchart involved in the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps in other steps.

[0193] Based on the same inventive concept, an embodiment of the present application further provides a battery expansion force testing device for implementing the battery expansion force testing method involved above. The solution provided by this device for solving problems is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the battery expansion force testing device provided below can refer to the limitations on the battery expansion force testing method in the above text, and will not be elaborated here.

[0194] In one embodiment, as Figure 11 shown, Figure 11 FIG. is a structural block diagram of a battery expansion force testing device provided by an embodiment of the present application. The battery expansion force testing device 1100 includes:

[0195] A first acquisition module 1101, configured to acquire a first physical property parameter at a first preset position of a restraint outside the battery to be tested;

[0196] A first determination module 1102, configured to determine the acting force of the battery to be tested under the first physical property parameter according to the first physical property parameter and an acting force model corresponding to a sample restraint that matches the restraint; the acting force model is used to characterize the corresponding relationship between the acting force applied to a target position in the sample restraint and the physical property parameter. The acting force model includes an acting force model corresponding to the physical property parameter type of the sample restraint. The first preset position matches the target position, and the physical property parameter type is the same as the parameter type of the first physical property parameter;

[0197] A second determination module 1103, configured to determine the expansion force test result of the battery to be tested according to the acting force under the first physical property parameter.

[0198] In one embodiment, the first physical property parameter includes at least one of an electrical parameter, a magnetic parameter, and a mechanical parameter.

[0199] In one embodiment, the restraint includes a steel strip, and the first physical property parameter includes an electrical parameter, and the electrical parameter is the electrical parameter detected by an electrical parameter tester at the first preset position.

[0200] In one embodiment, the restraint includes an end plate and / or a cross beam, and the first physical property parameter includes a magnetic parameter, and the magnetic parameter is the magnetic parameter detected by a magnetic parameter tester at the first preset position.

[0201] In one embodiment, the restraint includes at least one of a steel strip, an end plate, and a cross beam, and the first physical property parameter includes a mechanical parameter, and the mechanical parameter is the mechanical parameter detected by a mechanical parameter tester at the first preset position.

[0202] In one embodiment, as Figure 12 shown,Figure 12 It is a structural block diagram of a device for constructing a force model provided by an embodiment of the present application. The construction device 1200 includes:

[0203] A second acquisition module 1201, configured to acquire physical property parameters of a target position in a sample restraint under a force;

[0204] A construction module 1202, configured to construct a force model according to the force and the physical property parameters under the force.

[0205] In one embodiment, the sample restraint includes a sample steel strip. The second acquisition module 1201 is specifically configured to collect physical property parameters of the target position under different tensile forces through a physical property tester;

[0206] Wherein, if the physical property tester includes an electrical parameter tester, the physical property parameters include electrical parameters; if the physical property tester includes a mechanical parameter tester, the physical property parameters include mechanical parameters.

[0207] In one embodiment, the sample restraint includes a sample fixing member. The sample fixing member includes at least one of a sample end plate and a sample cross beam. The second acquisition module 1201 is specifically configured to collect physical property parameters of the target position under different extrusion forces through a physical property tester;

[0208] Wherein, if the physical property tester includes a magnetic parameter tester, the physical property parameters include magnetic parameters; if the physical property tester includes a mechanical parameter tester, the physical property parameters include mechanical parameters.

[0209] In one embodiment, the second acquisition module 1201 is specifically configured to collect physical property parameters of the target position under different extrusion forces through a physical property tester when filling a dummy battery disposed on one side of the sample fixing member with a gas that causes the large surface of the dummy battery to bulge and extruding the dummy battery with different extrusion forces by an extruder; wherein, the dummy battery is a battery without electrolyte injected.

[0210] In one embodiment, as Figure 13 shown, Figure 13 It is a structural block diagram of a device for determining test accuracy provided by an embodiment of the present application. The determination device 1300 includes:

[0211] A third acquisition module 1301, configured to acquire a target pressure of a verification battery under a preset number of cycles through a pressure sensor disposed in the verification battery;

[0212] A third determination module 1302, configured to determine the acting force at the second physical property parameter under the preset number of cycles according to the acting force model corresponding to the physical property parameter type of the sample binding member for verifying the external binding member of the battery and the second physical property parameter at the second preset position of the external binding member of the battery under the preset number of cycles; the parameter type of the second physical property parameter is the same as the physical property parameter type, and the second preset position matches the target position;

[0213] A fourth determination module 1303, configured to determine the test accuracy of the acting force model under the preset number of cycles according to the acting force corresponding to the preset number of cycles and the target pressure.

[0214] In one embodiment, the fourth determination module 1303 is specifically configured to determine the difference between the acting force corresponding to the preset number of cycles and the target pressure; and determine the test accuracy of the acting force model under the preset number of cycles according to the difference and the acting force corresponding to the preset number of cycles.

[0215] In one embodiment, the number of pressure sensors is multiple, and the third acquisition module 1301 is specifically configured to, under the preset number of cycles, acquire the pressures of the verified battery detected by each pressure sensor; and determine the target pressure of the verified battery under the preset number of cycles according to the pressures of the verified battery detected by each pressure sensor.

[0216] In one embodiment, the second determination module 1103 is further configured to determine that there is an abnormality in the binding member outside the battery to be tested if the first physical property parameter is outside the range of the physical property parameters characterized by the acting force model corresponding to the physical property parameter type.

[0217] Each module in the above battery expansion force test device can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor in the computer device in the form of hardware or be independent of the processor, or can be stored in the memory in the computer device in the form of software, so as to facilitate the processor to call and execute the operations corresponding to the above modules.

[0218] In one embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory. When the processor executes the computer program, the technical solutions in the embodiments of the battery expansion force test method of the present application are implemented. The implementation principle and technical effects are similar and will not be described in detail here.

[0219] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the technical solutions in the embodiments of the battery expansion force test method of the present application are implemented. The implementation principle and technical effects are similar and will not be described in detail here.

[0220] In one embodiment, a computer program product is provided, including a computer program which, when executed by a processor, implements the technical solutions in the above-mentioned embodiments of the battery expansion force test method of the present application. The implementation principle and technical effects are similar and will not be elaborated here.

[0221] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or fully authorized by all parties.

[0222] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing relevant hardware through a computer program. 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 above-mentioned method embodiments. Among them, any reference to a memory, database, or other medium used in the various embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memories can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memories can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the various embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the various embodiments provided in the present application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logic devices, data processing logics based on quantum computing, etc., without limitation.

[0223] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as the scope recorded in this specification.

[0224] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A battery expansion force testing method, characterized in that: The method comprises: Acquire a first physical characteristic parameter at a first preset position of a restraining member outside the battery to be tested; Determine the force of the battery to be tested under the first physical characteristic parameter according to the first physical characteristic parameter and the force model corresponding to the sample restraining piece matched with the restraining piece; the force model is used to characterize the correspondence between the force applied to the target position in the sample restraining piece and the physical characteristic parameter, the force model includes a force model corresponding to the physical characteristic parameter type of the sample restraining piece, the first preset position matches the target position, and the physical characteristic parameter type is the same as the parameter type of the first physical characteristic parameter; The expansion force test result of the battery to be tested is determined according to the force under the first physical characteristic parameter.

2. The method according to claim 1, characterized in that The first physical characteristic parameter includes at least one of an electrical parameter, a magnetic parameter and a mechanical parameter.

3. The method according to claim 2, characterized in that The restraining member includes a steel belt, and the first physical characteristic parameter includes the electrical parameter, which is an electrical parameter obtained by detecting the first preset position through an electrical parameter tester.

4. The method according to claim 2, characterized in that: The restraining member includes an end plate and / or a crossbeam, and the first physical characteristic parameter includes the magnetic parameter, which is a magnetic parameter obtained by detecting the first preset position through a magnetic parameter tester.

5. The method according to claim 2, characterized in that: The restraining member includes at least one of a steel belt, an end plate and a crossbeam, and the first physical characteristic parameter includes the mechanical parameter, which is obtained by detecting the first preset position through a mechanical parameter tester.

6. The method according to any one of claims 1 to 5, characterized in that: The method further comprises: Obtaining physical characteristic parameters of the target position in the sample restraint under the force; The force model is constructed according to the force and the physical characteristic parameters under the force.

7. The method according to claim 6, characterized in that The sample restraint comprises a sample steel belt, and obtaining the physical characteristic parameters of the target position in the sample restraint under the force comprises: Collecting the physical property parameters of the target position under different tensile forces by a physical property tester; If the physical property tester includes an electrical parameter tester, the physical property parameters include electrical parameters; if the physical property tester includes a mechanical parameter tester, the physical property parameters include mechanical parameters.

8. The method according to claim 6, characterized in that The sample restraint comprises a sample fixing member, and the sample fixing member comprises at least one of a sample end plate and a sample crossbeam, and the obtaining of the physical characteristic parameters of the target position in the sample restraint under the force comprises: Collecting physical property parameters of the target position under different extrusion pressures by a physical property tester; If the physical property tester includes a magnetic parameter tester, the physical property parameters include magnetic parameters; if the physical property tester includes a mechanical parameter tester, the physical property parameters include mechanical parameters.

9. The method according to claim 8, characterized in that The physical property parameters of the target position under different extrusion pressures are collected by a physical property tester, including: After the dummy battery cell disposed on one side of the sample fixture is filled with gas that causes the large surface of the dummy battery cell to swell, the dummy battery cell is squeezed by an extruder at different squeezing forces, and the physical property parameters of the target position under different squeezing forces are collected by a physical property tester; Wherein, the fake battery cell is a battery cell that is not injected with electrolyte.

10. The method according to any one of claims 1 to 5, characterized in that: The method further comprises: Obtaining a target pressure of the verification battery at a preset number of cycles through a pressure sensor disposed in the verification battery; Determine the force under the second physical characteristic parameter under the preset number of cycles according to the force model corresponding to the physical characteristic parameter type of the sample restraint that matches the verification battery external restraint and the second physical characteristic parameter at the second preset position of the verification battery external restraint under the preset number of cycles; the parameter type of the second physical characteristic parameter is the same as the physical characteristic parameter type, and the second preset position matches the target position; The test accuracy of the force model under the preset number of cycles is determined according to the force and target pressure corresponding to the preset number of cycles.

11. The method according to claim 10, characterized in that Determining the test accuracy of the force model under the preset number of cycles according to the force and target pressure corresponding to the preset number of cycles includes: Determining the difference between the applied force and the target pressure corresponding to the preset number of cycles; The test accuracy of the force model under the preset number of cycles is determined based on the difference and the force corresponding to the preset number of cycles.

12. The method according to claim 10, characterized in that The number of the pressure sensors is multiple, and the target pressure of the verification battery under a preset number of cycles is obtained by using the pressure sensors disposed in the verification battery, including: Under the preset number of cycles, obtaining the pressure of the verification battery detected by each of the pressure sensors; According to the pressure of the verification battery detected by each of the pressure sensors, a target pressure of the verification battery under a preset number of cycles is determined.

13. The method according to any one of claims 1 to 5, characterized in that: The method further comprises: If the first physical characteristic parameter is outside the interval range of the physical characteristic parameter represented by the force model corresponding to the physical characteristic parameter type, it is determined that there is an abnormality in the restraining member outside the battery to be tested.

14. A battery expansion force testing device, characterized in that: The device comprises: A first acquisition module, used to acquire a first physical characteristic parameter at a first preset position of a restraining member outside the battery to be tested; a first determination module, configured to determine the force of the battery to be tested under the first physical characteristic parameter according to the first physical characteristic parameter and a force model corresponding to a sample restraining member matching the restraining member; the force model is configured to characterize the correspondence between the force applied to a target position in the sample restraining member and the physical characteristic parameter, the force model comprising a force model corresponding to a physical characteristic parameter type of the sample restraining member, the first preset position matches the target position, and the physical characteristic parameter type is the same as a parameter type of the first physical characteristic parameter; The second determination module is used to determine the expansion force test result of the battery to be tested according to the force under the first physical characteristic parameter.

15. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 13 are implemented.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 13 are implemented.

17. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 13 are implemented.

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