A multi-parallel battery tab breakage detection method and device and electronic equipment

Abstract

This invention provides a method, apparatus, and electronic device for detecting tab breakage in multi-parallel batteries. The method includes: uniformly discharging to the discharge cutoff voltage and allowing it to stand; charging to full charge voltage at the same constant current and constant voltage rate according to a preset temperature; recording the corresponding temperature and the constant voltage time ti for each parallel cell; calculating t_avg and deviation Δt, as well as the slope of the ti data set; processing the data slope and deviation Δt in conjunction with a preset analysis strategy to obtain the corresponding detection results; the detection results include the presence of micro-fracture risk and / or tab breakage; its advantages are: the entire scheme is low-cost, only requiring judgment on the single characteristic quantity of constant voltage time, without considering multiple variations.

Description

Technical Field

[0001] This invention belongs to the field of battery testing technology, specifically relating to a method, device, and electronic equipment for detecting the breakage of tabs in multi-parallel batteries. Background Technology

[0002] With the development of the new energy battery field, the demand for battery capacity is increasing, and the requirement for longer driving range is also growing. Generally, increasing the number of batteries connected in parallel to form multiple parallel connections increases the usable capacity for users. However, in the parallel connection process, whether it's spot welding or damage to the tabs caused by drops or pressure in the user's hands, not only does this lead to a precipitous drop in battery capacity, but it may also trigger other short-circuit risks, reducing the user experience.

[0003] Currently, the commonly used solutions to the above problems have the following drawbacks:

[0004] 1. Based on visual inspection, it is necessary to rely on non-standard AOI inspection equipment to perform visual inspection of battery tabs by taking pictures, which is costly;

[0005] 2. As in the existing solution CN112363069A, capacity is calculated using capacity or dV / dQ and average discharge voltage. However, capacity calculation requires sufficient rest before capacity changes can be calculated, and the effects of charge and discharge conditions on capacity changes need to be considered. Furthermore, it is difficult to define failure boundaries for dV / dQ and average voltage calculations, and modeling and calibration are required for different batteries.

[0006] 3. Relying on external excitations such as DCR or EIS, DC impedance or AC impedance to obtain impedance changes, the impedance calculation has strict requirements on the operating conditions, and it is difficult to update in mobile phone-related operating conditions. Summary of the Invention

[0007] In view of the above problems, the present invention is proposed to provide a method, apparatus and electronic device for detecting the breakage of multi-parallel battery tabs in order to overcome the above problems or at least partially solve the above problems.

[0008] A first aspect of the present invention provides a method for detecting the breakage of tabs in multi-parallel batteries, the method comprising:

[0009] Discharge to the discharge cutoff voltage and let stand;

[0010] Based on the preset temperature, charge at a constant current and constant voltage at the same rate until full charge voltage is reached;

[0011] Record the corresponding temperature and the constant voltage time ti for each individual cell;

[0012] Calculate t_avg and deviation Δt, as well as the slope of the ti group of data; where Δt = |ti - t_avg|, and t_avg is calculated by averaging the historical constant pressure time recorded in advance;

[0013] The data slope and deviation Δt are processed using a preset analysis strategy to obtain the corresponding detection results; wherein, the detection results include the presence of micro-fracture risk and / or tab breakage.

[0014] As a preferred embodiment of this application, the historical constant pressure time is dynamically updated based on the detection cycle, and the new historical constant pressure time is calculated from the previously recorded constant pressure time.

[0015] When the constant voltage charging reaches the charging cutoff point, a breakage detection and average value update are triggered.

[0016] As a preferred embodiment of this application, the initial value of the historical constant voltage time is the constant voltage time corresponding to different battery temperatures stored in the standard charging process, which is used as a reference value and recorded as the normal group.

[0017] As a specific preferred embodiment of this application, the analysis strategy specifically includes:

[0018] The slope of the data is analyzed based on a preset first threshold; if the slope of the data is greater than the first threshold, it is considered that there is a risk of micro-fracture.

[0019] The deviation Δt is analyzed based on a preset second threshold; if the deviation Δt is greater than the second threshold, it can be determined that there is a broken tab.

[0020] As a preferred embodiment of this application, the second threshold is 2σ; where σ is the standard deviation of the constant voltage time corresponding to the normal group obtained through the standard charging process.

[0021] Secondly, a multi-parallel battery tab breakage detection device, characterized in that the device comprises:

[0022] The charge / discharge module is used for:

[0023] Discharge to the discharge cutoff voltage and let stand;

[0024] Based on the preset temperature, charge at a constant current and constant voltage at the same rate until full charge voltage is reached;

[0025] Processing module, used for:

[0026] Record the corresponding temperature and the constant voltage time ti for each individual cell;

[0027] Calculate t_avg and deviation Δt, as well as the slope of the ti group of data; where Δt = |ti - t_avg|, and t_avg is calculated by averaging the historical constant pressure time recorded in advance;

[0028] The detection module is used to process the data slope and deviation Δt in combination with a preset analysis strategy to obtain the corresponding detection results; wherein, the detection results include the presence of micro-fracture risk and / or tab breakage.

[0029] Thirdly, embodiments of the present invention also provide an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor is configured to run the computer program to perform a method for detecting the breakage of a multi-parallel battery tab as described in the first aspect.

[0030] As can be seen from the above technical solution, the present invention provides a method, device and electronic device for detecting the breakage of multi-parallel battery tabs. By comparing the constant voltage time obtained during the current detection with that obtained during standard charging, the slope and deviation Δt of the obtained data are processed in combination with a preset analysis strategy to obtain the corresponding detection result. This makes the whole solution low-cost, only requiring the determination of a single characteristic quantity of constant voltage time, without considering multiple changes, and can simplify the current direct characteristic judgment method of impedance by making an indirect judgment by the constant voltage time affected by impedance. Attached Figure Description

[0031] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0032] Figure 1 A flowchart of a method for detecting the breakage of tabs in a multi-parallel battery provided in an embodiment of the present invention;

[0033] Figure 2 This is a connection diagram of a multi-parallel battery tab breakage detection device provided in an embodiment of the present invention;

[0034] Figure 3 This is a connection diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0035] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore merely examples and should not be used to limit the scope of protection of the present invention. It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0036] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0037] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0038] As used in this specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrases "if determined" or "if [described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [described condition or event] is detected," or "in response to detection of [described condition or event]."

[0039] AOI: Automated Optical Inspection, is a high-speed, high-precision optical imaging inspection system that uses machine vision as the standard inspection technology;

[0040] DCR: Direct Current Resistance, specifically refers to the resistive characteristics of electronic components under direct current conditions, characterizing the conductor's resistance to direct current.

[0041] EIS: Electrochemical Impedance Spectroscopy, essentially measures the change of the AC impedance of a battery as a function of frequency by applying a small-amplitude sinusoidal AC signal to the battery.

[0042] It should be noted that, unless otherwise stated, the technical terms used in this embodiment have the common meaning as understood in the relevant technical field.

[0043] See Figure 1 The present invention provides a method for detecting the breakage of tabs in multi-parallel batteries, the method comprising:

[0044] S101, discharge to the discharge cutoff voltage and let stand;

[0045] S102, according to the preset temperature, and charged to full charge voltage at constant current and constant voltage at the same rate;

[0046] S103, record the corresponding temperature and the constant voltage time ti for each individual cell;

[0047] S104, calculate t_avg and deviation Δt, as well as the slope of the ti group of data; where Δt=|ti-t_avg|, and t_avg is calculated by averaging the historical constant pressure time recorded in advance;

[0048] S105, the data slope and deviation Δt are processed in conjunction with a preset analysis strategy to obtain the corresponding detection results; wherein, the detection results include the presence of micro-fracture risk and / or tab breakage.

[0049] It should be noted that the solution in this embodiment can be applied to BMS systems; the embodiment only describes the content that contributes to the present invention, and other existing technologies in actual applications are omitted here for the sake of simplicity; the relevant values ​​are only for illustrative purposes and are not intended to limit the present invention.

[0050] This embodiment takes the charging of a multi-parallel battery to full charge at 25℃-1C constant current and constant voltage as an example.

[0051] First, discharge the entire system to the discharge cutoff voltage of 3V and then let it stand.

[0052] Then charge at a constant current of 1C until the full charge voltage of 4.5V is reached;

[0053] Constant voltage charging was performed until the charging cutoff current reached 250mA. The corresponding temperature and constant voltage time ti for each individual cell in each parallel were recorded. ti includes t1, t2, t3...

[0054] It should be noted that the historical constant pressure time is dynamically updated based on the detection cycle, and the new historical constant pressure time is calculated based on the previously recorded constant pressure time.

[0055] When the constant voltage charging reaches the charging cutoff point, a breakage detection and average value update are triggered.

[0056] In application, the initial value of the historical constant voltage time is the constant voltage time corresponding to different battery temperatures stored in the standard charging process as a reference value, and it is recorded as the normal group.

[0057] The standard charging process includes:

[0058] First, based on the obtained cell specifications, the charging specifications for the battery at different temperatures and voltage ranges are obtained.

[0059] Secondly, the conventional charging process generally consists of two stages: constant current (CC) and constant voltage (CV). It can accumulate and store the CV constant voltage time from when the battery is fully charged to the corresponding full charge voltage, and the current temperature range; such as: temp_1_cv_time, temp_2_cv_time, temp_3_cv_time.

[0060] Then, the battery is charged according to the cell specifications, and different constant voltage times are stored as reference values, which are then compared with the corresponding operating conditions in the future.

[0061] The detection principle of this scheme is as follows: after the tab breaks, the connection resistance increases, which slows down the current decay time in the constant voltage stage, resulting in a significantly longer constant voltage time (under the same full charge cutoff current); the difference in constant voltage time between a normally connected cell and a broken cell is significantly greater than the natural difference between cells, which can be used as a stability criterion.

[0062] In this embodiment, the analysis strategy specifically includes:

[0063] The slope of the data is analyzed based on a preset first threshold; if the slope of the data is greater than the first threshold, it is considered that there is a risk of micro-fracture.

[0064] The deviation Δt is analyzed based on a preset second threshold. If the deviation Δt is greater than the second threshold, it can be determined that there is a broken tab. The second threshold is 2σ, where σ is the standard deviation of the constant voltage time corresponding to the normal group obtained through the standard charging process.

[0065] For example, the first threshold is set to 0, and the data slope is represented by k;

[0066] After analysis, when k is greater than 0, there is a risk of microfracture; if Δt > 2σ, it can be determined that there is a single-cell tab fracture.

[0067] The above scheme compares the constant voltage time obtained during the current test with that obtained by standard charging, and processes the obtained data slope and deviation Δt in combination with a preset analysis strategy to obtain the corresponding test results. This makes the whole scheme low-cost, only requiring the determination of a single characteristic quantity of constant voltage time, without having to consider multiple variations, and can simplify the current direct characteristic judgment method of impedance by making an indirect judgment by the constant voltage time affected by impedance.

[0068] Reference Figure 2 Based on the same inventive concept, a multi-parallel battery tab breakage detection device is provided, the device comprising:

[0069] The charge / discharge module is used for:

[0070] Discharge to the discharge cutoff voltage and let stand;

[0071] Based on the preset temperature, charge at a constant current and constant voltage at the same rate until full charge voltage is reached;

[0072] Processing module, used for:

[0073] Record the corresponding temperature and the constant voltage time ti for each individual cell;

[0074] Calculate t_avg and deviation Δt, as well as the slope of the ti group of data; where Δt = |ti - t_avg|, and t_avg is calculated by averaging the historical constant pressure time recorded in advance;

[0075] The detection module is used to process the data slope and deviation Δt in combination with a preset analysis strategy to obtain the corresponding detection results; wherein, the detection results include the presence of micro-fracture risk and / or tab breakage.

[0076] In this embodiment, the historical constant pressure time is dynamically updated based on the detection cycle, and the new historical constant pressure time is calculated based on the previously recorded constant pressure time.

[0077] When the constant voltage charging reaches the charging cutoff point, a breakage detection and average value update are triggered.

[0078] Furthermore, the analysis strategy specifically includes:

[0079] The slope of the data is analyzed based on a preset first threshold; if the slope of the data is greater than the first threshold, it is considered that there is a risk of micro-fracture.

[0080] The deviation Δt is analyzed based on a preset second threshold; if the deviation Δt is greater than the second threshold, it can be determined that there is a broken tab.

[0081] It should be noted that for a more detailed description of the working process of the device embodiments, please refer to the foregoing method embodiments section, which will not be repeated here.

[0082] The entire solution is low-cost, requiring only a single characteristic quantity, constant voltage time, without needing to consider multiple variations. It also simplifies the current direct characteristic judgment method of impedance by indirectly judging the constant voltage time affected by impedance.

[0083] In another embodiment of the present invention, an electronic device is also provided, with reference to... Figure 3 The method includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement a method for detecting the breakage of a multi-parallel battery tab as described above.

[0084] It should be noted that if the aforementioned functions are implemented as software functional units 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 this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause an electronic device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0085] In the several embodiments provided in this application, it should be understood that the described apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0086] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit. The scope of the preferred embodiments of this application includes other implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order according to the functions involved, as should be understood by those skilled in the art to which the embodiments of this application pertain.

[0087] The integrated modules described above can be implemented in either hardware or software. When used, each module will only collect and store user information with the user's full authorization and in compliance with relevant laws and regulations, protecting the security and privacy of user data and strictly prohibiting unauthorized access. Data processing will be conducted within the scope stipulated by law and will not exceed the purposes and scope authorized by the user. Users have the right to access, correct, delete, restrict, and refuse processing of their personal data, and must strictly comply with applicable laws and regulations and undergo compliance reviews.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for detecting broken tabs in multi-parallel batteries, characterized in that, The method includes: Discharge to the discharge cutoff voltage and let stand; Based on the preset temperature, charge at a constant current and constant voltage at the same rate until full charge voltage is reached; Record the corresponding temperature and the constant voltage time ti for each individual cell; Calculate t_avg and deviation Δt, as well as the slope of the ti group of data; where Δt = |ti - t_avg|, and t_avg is calculated by averaging the historical constant pressure time recorded in advance; The data slope and deviation Δt are processed using a preset analysis strategy to obtain the corresponding detection results; wherein, the detection results include the presence of micro-fracture risk and / or tab breakage.

2. The method for detecting the breakage of tabs in a multi-parallel battery according to claim 1, characterized in that, The historical constant pressure time is dynamically updated based on the detection cycle, and the new historical constant pressure time is calculated from the previously recorded constant pressure time. When the constant voltage charging reaches the charging cutoff point, a breakage detection and average value update are triggered.

3. The method for detecting broken tabs in multi-parallel batteries according to claim 2, characterized in that, The initial value of the historical constant voltage time is the constant voltage time corresponding to different battery temperatures stored in the standard charging process, which is used as a reference value and recorded as the normal group.

4. The method for detecting the breakage of tabs in a multi-parallel battery according to claim 3, characterized in that, The analysis strategy specifically includes: The slope of the data is analyzed based on a preset first threshold; if the slope of the data is greater than the first threshold, it is considered that there is a risk of micro-fracture. The deviation Δt is analyzed based on a preset second threshold; if the deviation Δt is greater than the second threshold, it can be determined that there is a broken tab.

5. The method for detecting the breakage of tabs in a multi-parallel battery according to claim 4, characterized in that, The second threshold is 2σ; where σ is the standard deviation of the constant voltage time corresponding to the normal group obtained through the standard charging process.

6. A device for detecting the breakage of tabs in multi-parallel batteries, characterized in that, The device includes: The charge / discharge module is used for: Discharge to the discharge cutoff voltage and let stand; Based on the preset temperature, charge at a constant current and constant voltage at the same rate until full charge voltage is reached; Processing module, used for: Record the corresponding temperature and the constant voltage time ti for each individual cell; Calculate t_avg and deviation Δt, as well as the slope of the ti group of data; where Δt = |ti - t_avg|, and t_avg is calculated by averaging the historical constant pressure time recorded in advance; The detection module is used to process the data slope and deviation Δt in combination with a preset analysis strategy to obtain the corresponding detection results; wherein, the detection results include the presence of micro-fracture risk and / or tab breakage.

7. The apparatus according to claim 6, characterized in that, The historical constant pressure time is dynamically updated based on the detection cycle, and the new historical constant pressure time is calculated from the previously recorded constant pressure time. When the constant voltage charging reaches the charging cutoff point, a breakage detection and average value update are triggered.

8. The apparatus according to claim 7, characterized in that, The analysis strategy specifically includes: The slope of the data is analyzed based on a preset first threshold; if the slope of the data is greater than the first threshold, it is considered that there is a risk of micro-fracture. The deviation Δt is analyzed based on a preset second threshold; if the deviation Δt is greater than the second threshold, it can be determined that there is a broken tab.

9. An electronic device, characterized in that, The electronic device includes a processor and a memory: The memory is used to store computer programs; The processor is used to run the computer program to perform a method for detecting the breakage of a multi-parallel battery tab as described in any one of claims 15.

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