Battery analysis method, system and equipment and storage medium

Abstract

The invention relates to the technical field of battery detection, and discloses a battery analysis method, system and device and a storage medium. The method comprises the following steps: applying external pressure to a positive aluminum plate of a failed battery, and testing a first battery parameter of the failed battery; judging whether the first battery parameter meets a battery parameter analysis condition or not; if yes, stopping applying the external pressure, and carrying out charging and discharging test on the failed battery; and acquiring a second battery parameter of the failed battery during the charging and discharging test, and analyzing a failure reason of the failed battery according to the second battery parameter. The failure battery can be detected under the condition that the failure battery is not damaged, the failure reason of the failure battery is analyzed, and the analysis result is more accurate.

Description

Technical Field

[0001] The present application relates to the field of battery detection technology, and in particular to a battery analysis method, system, device and storage medium. Background Art

[0002] Lithium-ion batteries have the characteristics of high energy density and long cycle life, and are considered to be the core technology for large-scale energy storage and electric vehicles. In order to ensure the safety of lithium-ion batteries, a current interrupt device (CID) is usually installed inside the battery. The CID will flip when the battery cell fails, and the solder joints on the positive aluminum plate of the battery will fall off, causing the internal circuit of the battery cell to break, thereby playing a protective role. In order to analyze the cause of battery failure, the existing method requires the failed battery to be disassembled and analyzed, and non-destructive analysis cannot be performed, which may cause the analysis results to deviate from the actual situation. Summary of the invention

[0003] In order to analyze the cause of battery failure without destroying the battery, the present application provides a battery analysis method, system, device and storage medium.

[0004] In a first aspect, the present application provides a battery analysis method, comprising:

[0005] Applying external pressure to the positive aluminum plate of the failed battery and testing a first battery parameter of the failed battery;

[0006] Determining whether the first battery parameter meets a battery parameter analysis condition;

[0007] If the conditions are met, stop applying the external pressure and perform a charge and discharge test on the failed battery;

[0008] A second battery parameter of the failed battery during a charge and discharge test is acquired, and a failure cause of the failed battery is analyzed according to the second battery parameter.

[0009] In one embodiment, the first battery parameter includes a battery voltage and a battery internal resistance, and the determining whether the first battery parameter meets a battery parameter analysis condition includes:

[0010] Determining whether the battery voltage is greater than a voltage threshold;

[0011] If it is greater than the voltage threshold, determining whether the battery internal resistance is less than the resistance threshold;

[0012] If it is less than the resistance threshold, it is determined that the first battery parameter meets the battery parameter analysis condition.

[0013] In one embodiment, the method further comprises:

[0014] If the battery voltage is less than or equal to the voltage threshold, or the battery internal resistance is greater than or equal to the resistance threshold, then continue to apply external pressure to the failed battery.

[0015] In one embodiment, the method further comprises:

[0016] If the first battery parameter meets the battery parameter analysis condition, it is determined that the positive aluminum plate of the failed battery is normally connected to the battery cell of the failed battery.

[0017] In one embodiment, the charging and discharging test of the failed battery includes:

[0018] Charging and discharging the failed battery a preset number of times according to a first preset power;

[0019] Then, the failed battery is discharged to a preset capacity according to a second preset power.

[0020] In one embodiment, the second battery parameter includes an electrochemical impedance spectrum, and the step of obtaining the second battery parameter of the failed battery during the charge and discharge test includes:

[0021] The electrochemical impedance spectrum corresponding to the failed battery being discharged to the preset capacity is obtained.

[0022] In one embodiment, the second battery parameter further includes differential capacity, and the step of obtaining the second battery parameter of the failed battery during the charge and discharge test includes:

[0023] Acquire a first voltage of the failed battery when the SOC is 0%, and acquire a second voltage of the failed battery when the SOC is 100%;

[0024] The differential capacity is calculated according to the first voltage and the second voltage.

[0025] In a second aspect, the present application provides a battery analysis system, comprising:

[0026] A pressure module, used for applying external pressure to the positive aluminum plate of the failed battery and testing a first battery parameter of the failed battery;

[0027] A judging module, used for judging whether the first battery parameter satisfies a battery parameter analysis condition;

[0028] A testing module, used for stopping applying the external pressure if the conditions are met, and performing a charge and discharge test on the failed battery;

[0029] The analysis module is used to obtain a second battery parameter of the failed battery during a charge and discharge test, and analyze the failure cause of the failed battery according to the second battery parameter.

[0030] In a third aspect, the present application provides a computer device, comprising a processor and a memory, wherein the memory stores a computer program, and the processor is used to execute the computer program to implement the battery analysis method described in the first aspect.

[0031] In a fourth aspect, the present application provides a computer storage medium storing a computer program, wherein when the computer program is executed on a processor, the battery analysis method according to the first aspect is implemented.

[0032] The embodiments of the present application have the following beneficial effects:

[0033] The present application provides a battery analysis method, which applies external pressure to the positive aluminum plate of a failed battery so that the failed battery meets the test conditions, and then performs charge and discharge tests on the failed battery to determine the failure cause of the failed battery. Since the positive aluminum plate of the battery and the battery cell will be disconnected when the battery fails, the distance between the positive aluminum plate and the battery cell can be gradually shortened by applying pressure to the positive aluminum plate of the battery, and finally connected, so that the failed battery returns to a normal state and then is tested again. This method will not cause damage to the battery and the detection result is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present application and should not be regarded as limiting the scope of protection of the present application. For ordinary technicians in this field, other related drawings can also be obtained based on these drawings without creative work.

[0035] Figure 1 A schematic diagram of a battery analysis method provided in an embodiment of the present application is shown;

[0036] Figure 2 A schematic diagram of a process for determining a battery parameter analysis condition is shown in an embodiment of the present application;

[0037] Figure 3 It shows that an embodiment of the present application provides a battery voltage change curve diagram over time;

[0038] Figure 4 The embodiment of the present application provides a battery capacity and voltage variation curve diagram;

[0039] Figure 5 The embodiment of the present application provides a schematic diagram of the variation of differential capacity with voltage;

[0040] Figure 6The present invention provides a schematic diagram of comparing electrochemical impedance spectra of a failed battery and an experimental battery;

[0041] Figure 7 A schematic diagram of the framework structure of a battery analysis system provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0043] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0044] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present application, are intended only to indicate specific features, numbers, steps, operations, elements, components, or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing items or adding the possibility of one or more features, numbers, steps, operations, elements, components, or combinations of the foregoing items.

[0045] Furthermore, the terms “first”, “second”, “third”, etc. are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0046] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meanings as those generally understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meanings as the contextual meanings in the relevant technical field and will not be interpreted as having idealized meanings or overly formal meanings unless clearly defined in the various embodiments of the present application.

[0047] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0048] Reference Figure 1 , Figure 1A schematic flow chart of a battery analysis method provided in this embodiment, which can realize non-destructive detection of failed batteries, includes:

[0049] S101, applying external pressure to the positive aluminum plate of the failed battery, and testing a first battery parameter of the failed battery.

[0050] Common lithium-ion batteries on the market are usually equipped with corresponding current interrupt devices (CID). When the battery cell fails, such as overheating, short circuit, overcharging, etc., a lot of gas will be generated inside the battery. When the pressure increases, the solder joints welded to the positive aluminum plate and the pressure relief plate of the battery will fall off, and the pressure relief plate will flip over, causing the internal circuit of the battery cell to be broken, thus playing a protective role.

[0051] Therefore, when the CID flips over in the battery, the battery cell and the positive aluminum plate will be disconnected. Since the positive aluminum plate is a deformable material, applying external pressure to the positive aluminum plate at this time can make the positive aluminum plate gradually approach the battery cell.

[0052] S102: Determine whether the first battery parameter meets a battery parameter analysis condition.

[0053] While applying external pressure to the positive aluminum plate, the first battery parameter of the battery is detected in real time to determine whether the positive aluminum plate is reconnected to the battery cell. If the positive aluminum plate is reconnected to the battery cell, the first parameter of the battery will be significantly different from the parameter when the battery undergoes CID flipping.

[0054] S103: If the conditions are met, stop applying the external pressure and perform a charge and discharge test on the failed battery.

[0055] If the first battery parameter of the battery meets the battery parameter analysis condition, then the application of external pressure to the positive aluminum plate of the battery is stopped, and a charge and discharge test is performed on the failed battery.

[0056] S104: Acquire a second battery parameter of the failed battery during a charge and discharge test, and analyze a failure cause of the failed battery according to the second battery parameter.

[0057] Since the positive aluminum plate of the battery is connected to the battery cell, the second battery parameters collected during the charge and discharge test can be regarded as the parameters of the battery when the CID flip occurs. Based on the second battery parameters, the reasons for the failure of the failed battery and the CID flip can be analyzed.

[0058] In this embodiment, external pressure is applied to the positive aluminum plate of the failed battery so that the failed battery meets the test conditions, and then the charge and discharge test is performed on the failed battery to determine the failure cause of the failed battery. Since the positive aluminum plate of the battery will be disconnected from the battery cell when the battery fails, the distance between the positive aluminum plate and the battery cell can be gradually shortened by applying pressure to the positive aluminum plate of the battery, and finally the connection is achieved, so that the failed battery returns to a normal state and then is tested. This method will not damage the battery and the detection result is more accurate.

[0059] The first battery parameter includes battery voltage and battery internal resistance.

[0060] Reference Figure 2 , step S102 includes: steps S1021-S1023.

[0061] S1021. Determine whether the battery voltage is greater than a voltage threshold.

[0062] S1022: If the voltage is greater than the voltage threshold, determine whether the battery internal resistance is less than the resistance threshold;

[0063] S1023: If the resistance is less than the resistance threshold, determine that the first battery parameter meets the battery parameter analysis condition.

[0064] When the CID of the battery flips, the battery cell is short-circuited and the battery voltage becomes 0. Therefore, when applying pressure to the positive aluminum plate of the battery, the battery voltage can be tested at the same time. If the voltage is greater than 0, it means that the positive aluminum plate of the battery is connected to the battery cell.

[0065] When the battery has a CID flip, the battery internal resistance can be regarded as infinite due to the short circuit of the battery cell. In order to ensure that the battery cell is restored to the state before the CID flip, it is also necessary to detect the battery internal resistance when applying pressure to the positive aluminum plate of the battery to determine that the battery internal resistance is less than the resistance threshold. For example, the initial internal resistance of the battery is 50 milliohms, and the resistance threshold can be set to 130% of the initial internal resistance, that is, 65 milliohms. When applying pressure to the positive aluminum plate, the battery internal resistance is detected at the same time. If the battery internal resistance is less than 65 milliohms, it means that the battery has now recovered to the state before the CID flip. Users can also set the corresponding voltage threshold and internal resistance threshold according to actual conditions to improve the accuracy of the detection results.

[0066] If the battery voltage is less than or equal to the voltage threshold, or the battery internal resistance is greater than or equal to the resistance threshold, then continue to apply external pressure to the failed battery.

[0067] If the battery voltage or battery internal resistance does not meet the battery parameter analysis conditions, it means that the connection between the positive aluminum plate and the battery cell is unstable. At this time, it is necessary to continue to apply pressure to the positive aluminum plate of the failed battery until the failed battery meets the battery parameter analysis conditions. At this time, it is determined that the positive aluminum plate of the failed battery is normally connected to the battery cell of the failed battery.

[0068] This embodiment ensures the accuracy and scientificity of the analysis results by simultaneously detecting the battery voltage and the battery internal resistance when applying external force to the positive aluminum plate of the battery, and judging whether the battery meets the battery parameter analysis conditions based on the detection results.

[0069] Reference Figure 3 , Figure 3 A battery voltage variation curve diagram provided in this embodiment.

[0070] At the beginning, the open circuit voltage (OCV) of the battery is 0V. After applying pressure to the positive aluminum plate of the battery to restore the battery to the state before the CID flip, the OCV of the battery returns to normal.

[0071] In one embodiment, the charging and discharging test of the failed battery includes:

[0072] Charging and discharging the failed battery a preset number of times according to a first preset power;

[0073] Then, the failed battery is discharged to a preset capacity according to a second preset power.

[0074] For example, the battery can be charged with a small current first, and then discharged with a large current, and cycled multiple times, wherein the small current can be 0.1-0.2C, the large current can be 0.5-2C, and then charged and discharged once at 0.05C, and the differential capacity dq / dv can be obtained by testing.

[0075] Reference Figure 4 , Figure 4 A battery capacity and voltage variation curve diagram provided in this embodiment.

[0076] according to Figure 4 It can be seen that the battery capacity is around 4.5Ah, indicating that the degradation of the battery active materials is not serious.

[0077] In one embodiment, the second battery parameter further includes differential capacity, and the step of obtaining the second battery parameter of the failed battery during the charge and discharge test includes:

[0078] Acquire a first voltage of the failed battery when the SOC is 0%, and acquire a second voltage of the failed battery when the SOC is 100%;

[0079] The differential capacity is calculated according to the first voltage and the second voltage.

[0080] Reference Figure 5 , Figure 5 A schematic diagram of the variation of differential capacity with voltage provided in this embodiment.

[0081] In one embodiment, the second battery parameter includes an electrochemical impedance spectrum, and the step of obtaining the second battery parameter of the failed battery during the charge and discharge test includes:

[0082] The electrochemical impedance spectrum corresponding to the failed battery being discharged to the preset capacity is obtained.

[0083] Reference Figure 6 , Figure 6 Schematic diagram of the electrochemical impedance spectrum comparison between the failed battery and the experimental battery.

[0084] It can be seen that there is a large difference in the electrochemical impedance spectra between the failed battery and the experimental battery, indicating that the battery interface is seriously different. The experimental battery also has the problem of excessive interface impedance, which means that the reason for the battery failure may be the large interface impedance.

[0085] This embodiment performs charge and discharge tests on the battery and obtains battery parameters during the charge and discharge process, and determines the failure cause of the battery according to the battery parameters, which will not cause damage to the battery and has a more accurate result.

[0086] Reference Figure 7 , the present application provides a battery analysis system 700, including:

[0087] A pressure module 701 is used to apply external pressure to the positive aluminum plate of the failed battery and test a first battery parameter of the failed battery;

[0088] A judging module 702 is used to judge whether the first battery parameter meets the battery parameter analysis condition;

[0089] A testing module 703 is used to stop applying the external pressure if the conditions are met, and perform a charge and discharge test on the failed battery;

[0090] The analysis module 704 is used to obtain a second battery parameter of the failed battery during the charge and discharge test, and analyze the failure cause of the failed battery according to the second battery parameter.

[0091] It can be understood that the battery analysis system of this embodiment corresponds to the battery analysis method of the above embodiment, and the options in the above embodiment are also applicable to this embodiment, so they will not be described repeatedly here.

[0092] The present application also provides a computer device. Exemplarily, the computer device includes a processor and a memory, wherein the memory stores a computer program, and the processor runs the computer program to enable the computer device to execute the functions of each module in the above-mentioned battery analysis method or the above-mentioned battery analysis system.

[0093] Among them, the processor can be an integrated circuit chip with signal processing capabilities. The processor can be a general-purpose processor, including a central processing unit (CPU), a graphics processing unit (GPU) and a network processor (NP), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or at least one of other programmable logic devices, discrete gates or transistor logic devices, and discrete hardware components. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc., which can implement or execute the disclosed methods, steps and logic block diagrams in the embodiments of the present application.

[0094] The memory may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), etc. The memory is used to store a computer program, and the processor may execute the computer program accordingly after receiving an execution instruction.

[0095] The present application also provides a computer storage medium for storing the computer program used in the above-mentioned computer device. The computer storage medium may be a readable storage medium, or a non-volatile storage medium or a volatile storage medium. For example, the computer storage medium may include, but is not limited to, various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0096] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and structure diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in an alternative implementation, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the structure diagram and / or the flow diagram, and the combination of boxes in the structure diagram and / or the flow diagram, can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0097] In addition, the functional modules or units in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0098] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a smart phone, a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the various embodiments of the present application.

[0099] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A battery analysis method, characterized in that: include: Applying external pressure to the positive aluminum plate of the failed battery and testing a first battery parameter of the failed battery; Determining whether the first battery parameter meets a battery parameter analysis condition; If the conditions are met, stop applying the external pressure and perform a charge and discharge test on the failed battery; A second battery parameter of the failed battery during a charge and discharge test is acquired, and a failure cause of the failed battery is analyzed according to the second battery parameter.

2. The battery analysis method according to claim 1, characterized in that: The first battery parameter includes a battery voltage and a battery internal resistance, and the determining whether the first battery parameter meets a battery parameter analysis condition includes: Determining whether the battery voltage is greater than a voltage threshold; If it is greater than the voltage threshold, determining whether the battery internal resistance is less than the resistance threshold; If it is less than the resistance threshold, it is determined that the first battery parameter meets the battery parameter analysis condition.

3. The battery analysis method according to claim 2, characterized in that: The method further comprises: If the battery voltage is less than or equal to the voltage threshold, or the battery internal resistance is greater than or equal to the resistance threshold, then continue to apply external pressure to the failed battery.

4. The battery analysis method according to claim 1, characterized in that: The method further comprises: If the first battery parameter meets the battery parameter analysis condition, it is determined that the positive aluminum plate of the failed battery is normally connected to the battery cell of the failed battery.

5. The battery analysis method according to claim 1, characterized in that: The charging and discharging test of the failed battery includes: Charging and discharging the failed battery a preset number of times according to a first preset power; Then, the failed battery is discharged to a preset capacity according to a second preset power.

6. The battery analysis method according to claim 5, characterized in that: The second battery parameter includes an electrochemical impedance spectrum, and the step of obtaining the second battery parameter of the failed battery during the charge and discharge test includes: The electrochemical impedance spectrum corresponding to the failed battery being discharged to the preset capacity is obtained.

7. The battery analysis method according to claim 5, characterized in that: The second battery parameter also includes differential capacity, and the step of obtaining the second battery parameter of the failed battery during the charge and discharge test includes: Acquire a first voltage of the failed battery when the SOC is 0%, and acquire a second voltage of the failed battery when the SOC is 100%; The differential capacity is calculated according to the first voltage and the second voltage.

8. A battery analysis system, characterized in that: include: A pressure module, used for applying external pressure to the positive aluminum plate of the failed battery and testing a first battery parameter of the failed battery; A judging module, used for judging whether the first battery parameter satisfies a battery parameter analysis condition; A testing module, used for stopping applying the external pressure if the conditions are met, and performing a charge and discharge test on the failed battery; The analysis module is used to obtain a second battery parameter of the failed battery during a charge and discharge test, and analyze the failure cause of the failed battery according to the second battery parameter.

9. A computer device, characterized in that: The computer device comprises a processor and a memory, wherein the memory stores a computer program, and the processor is configured to execute the computer program to implement the battery analysis method according to any one of claims 1 to 7.

10. A computer storage medium, characterized in that: The computer program is stored therein, and when the computer program is executed on a processor, the battery analysis method according to any one of claims 1 to 7 is implemented.

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