Battery detection method, device, equipment, storage medium and program product

Abstract

The present application provides a battery detection method, device, equipment, storage medium and program product. The detection method includes obtaining charging data of a battery under test during a formation process; the charging data includes a reference parameter and a parameter to be measured, wherein one of the reference parameter and the parameter to be measured is a voltage value and the other is the charging time required to charge to the corresponding voltage value; based on the charging data of the battery under test, determining the parameter value of the parameter to be measured of the battery under test when the reference parameter is in a range to be estimated; and judging whether the battery under test is normal based on the comparison result of the parameter value of the parameter to be measured of the battery under test when the reference parameter is in the range to be estimated and the benchmark reference value. In this way, the detection method can be used to test the performance of the battery with the help of the charging data of the formation process before the static process and the testing process of the battery manufacturing, so as to screen out unqualified batteries in advance, without having to put the battery aside for a period of time, which is conducive to shortening the battery testing time and test cycle.

Description

Technical Field

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

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the sustainable development of the automotive industry. For electric vehicles, battery technology is a key factor in their development.

[0003] Before leaving the factory, finished batteries must be tested to screen out substandard batteries. Conventional technology typically places the finished batteries aside for a period of time, then monitors parameters such as the battery's charge level or K value to verify their normal operation. However, this method takes a long time to test battery quality and requires a long testing cycle. Summary of the Invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present application is to provide a battery testing method, device, equipment, storage medium and program product to solve the problem that testing whether a battery is qualified takes a long time and has a long test cycle.

[0005] An embodiment of the first aspect of the present application provides a battery detection method, comprising: obtaining charging data of a battery under test during a formation process; the charging data comprising a reference parameter and a parameter to be measured, wherein one of the reference parameter and the parameter to be measured is a voltage value and the other is a charging time required to charge to a corresponding voltage value; determining, based on the charging data of the battery under test, a parameter value of the parameter to be measured of the battery under test when the reference parameter is in an interval to be estimated; and judging whether the battery under test is normal based on a comparison result of the parameter value of the parameter to be measured of the battery under test when the reference parameter is in the interval to be estimated and a benchmark reference value.

[0006] In the technical solution of the embodiment of the present application, the detection method is used to test the performance of the battery with the help of the charging data of the formation process before the static process and testing process of battery manufacturing, so as to screen out unqualified batteries in advance. In this way, there is no need to put the battery on hold for a period of time, which is conducive to shortening the battery testing time and test cycle, improving the testing efficiency, and thus helping to alleviate the pressure on storage space and cash flow of battery manufacturers.

[0007] And, because the formation process is the necessary processing procedure for each battery, therefore, adopting this detection method to test the performance of the battery, can make full use of the data of the formation process, improved the utilization rate of the charging data of the formation process. In addition, the mode of detecting the performance of the battery by the mode of shelving often can only carry out random inspection to the battery, utilize the detection method of the present embodiment, each battery can use its charging data in the formation process to carry out performance test, and then can realize the effect of full inspection of the battery, namely each battery all can carry out performance test, is conducive to avoiding unqualified battery to leave the factory.

[0008] In some embodiments, the reference parameter is charging time, and the parameter to be measured is voltage. Determining whether the battery under test is normal is based on a comparison result between the parameter value of the battery under test when the reference parameter is in the estimated interval and a baseline reference value. This includes: comparing the voltage value corresponding to the battery under test when the charging time is a first preset value with the first reference value to obtain a first comparison result; comparing the voltage value corresponding to the battery under test when the charging time is a second preset value with the second reference value to obtain a second comparison result; and determining whether the battery under test is normal based on the first and second comparison results. In this way, multiple reference parameters can be taken, and multiple sets of parameters to be measured can be obtained for the battery under test, which is conducive to improving the accuracy of the test.

[0009] In some embodiments, the difference between the voltage value corresponding to the battery under test when the charging time is the first preset value and the voltage value corresponding to the battery under test when the charging time is the second preset value is greater than 0.5 V. In this way, the difference between the two sets of measured parameters of the battery under test is large, which makes it easier to calculate and obtain accurate comparison results, thereby improving the accuracy of the detection.

[0010] In some embodiments, before judging whether the battery under test is normal based on the comparison result of the parameter value of the measured parameter of the battery under test when the reference parameter is in the interval to be estimated and the benchmark reference value, it also includes: obtaining the charging data of the reference battery; determining the parameter value of the measured parameter of the reference battery when the reference parameter is in the interval to be estimated based on the charging data of the reference battery; determining the benchmark reference value based on the parameter value of the measured parameter of the reference battery when the reference parameter is in the interval to be estimated.

[0011] In the detection method of this embodiment, the benchmark reference value is designed based on the actual charging data of the reference battery in the formation process. In this way, the benchmark reference value is not prone to error and is reasonably designed.

[0012] In some embodiments, determining the baseline reference value based on the parameter value of the measured parameter of the reference battery when the reference parameter is within the estimated interval includes determining the baseline reference value based on the average parameter value of the measured parameter of multiple reference batteries when the reference parameter is within the estimated interval. This helps reduce the impact of errors in a single value on the test, thereby improving test accuracy.

[0013] In some embodiments, determining whether the battery under test is normal is performed based on a comparison between a parameter value of the battery under test when the reference parameter is in the interval to be estimated and a baseline reference value. This includes: establishing a first relationship curve for the battery under test based on the charging data of the battery under test; establishing a second relationship curve for the reference battery based on the charging data of the reference battery; and determining whether the battery under test is normal based on a comparison between the estimated segment of the first relationship curve and the estimated segment of the second relationship curve; wherein the estimated segment of the first relationship curve is the curve segment of the first relationship curve where the reference parameter is in the interval to be estimated, and the estimated segment of the second relationship curve is the curve segment of the second relationship curve where the reference parameter is in the interval to be estimated. Determining whether the battery under test is abnormal is performed by comparing a relationship curve graph obtained by fitting the charging data of the battery under test with a relationship curve graph obtained by fitting the charging data of the reference battery.

[0014] In some embodiments, the charging data also includes the power value when charged to the corresponding voltage value; after obtaining the charging data of the battery under test during the formation process, the battery detection method also includes: determining the resistance value of the battery under test based on the charging data of the battery under test; and judging whether the battery under test is normal based on the comparison result of the resistance value of the battery under test and the reference resistance value.

[0015] The detection method of this embodiment can also detect the resistance value of the battery under test. By comparing the resistance value of the battery under test with the reference resistance value, it can be determined whether the internal resistance of the battery under test is normal. In other words, the detection method of this embodiment is suitable for detecting the internal resistance performance of a battery.

[0016] The second embodiment of the present application provides a battery detection device, comprising: a data acquisition module, a determination module, and a judgment module. The data acquisition module is used to acquire charging data of a battery under test during a formation process; the charging data includes a reference parameter and a parameter to be measured, wherein one of the reference parameter and the parameter to be measured is a voltage value and the other is the charging time required to charge to the corresponding voltage value; the determination module is used to determine, based on the charging data of the battery under test, the parameter value of the parameter to be measured of the battery under test when the reference parameter is within an estimated interval; and the judgment module is used to determine whether the battery under test is normal based on a comparison result of the parameter value of the parameter to be measured of the battery under test when the reference parameter is within the estimated interval with a baseline reference value.

[0017] In some embodiments, the reference parameter is the charging time, the parameter to be measured is the voltage value, and the judgment module is further configured to compare the voltage value corresponding to the battery under test when the charging time is a first preset value with the first reference value to obtain a first comparison result; compare the voltage value corresponding to the battery under test when the charging time is a second preset value with the second reference value to obtain a second comparison result; and judge whether the battery under test is normal based on the first comparison result and the second comparison result.

[0018] In some embodiments, a difference between a voltage value corresponding to a first preset charging time of the battery under test and a voltage value corresponding to a second preset charging time of the battery under test is greater than 0.5V.

[0019] In some embodiments, the data acquisition module is further configured to acquire the charging data of the reference battery before judging whether the battery under test is normal based on the comparison result of the parameter value of the measured parameter of the battery under test when the reference parameter is in the interval to be estimated and the benchmark reference value; the determination module is further configured to determine the parameter value of the measured parameter of the reference battery when the reference parameter is in the interval to be estimated based on the charging data of the reference battery; the judgment module is further configured to determine the benchmark reference value based on the parameter value of the measured parameter of the reference battery when the reference parameter is in the interval to be estimated.

[0020] In some embodiments, the determination module is further configured to determine the benchmark reference value according to an average value of parameter values ​​of the measured parameters of a plurality of reference batteries when the reference parameter is in the interval to be estimated.

[0021] In some embodiments, the judgment module is further configured to establish a first relationship curve for the battery under test based on the charging data of the battery under test; establish a second relationship curve for the reference battery based on the charging data of the reference battery; and judge whether the battery under test is normal based on the comparison result of the to-be-estimated segment of the first relationship curve and the to-be-estimated segment of the second relationship curve; wherein the to-be-estimated segment of the first relationship curve is a curve segment in which the reference parameter in the first relationship curve is in the to-be-estimated interval, and the to-be-estimated segment of the second relationship curve is a curve segment in which the reference parameter in the second relationship curve is in the to-be-estimated interval.

[0022] In some embodiments, the charging data also includes the power value when charged to the corresponding voltage value; the determination module is further configured to determine the resistance value of the battery under test based on the charging data of the battery under test after the data acquisition module obtains the charging data of the battery under test during the formation process; the judgment module is further configured to judge whether the battery under test is normal based on the comparison result of the resistance value of the battery under test and the reference resistance value.

[0023] An embodiment of the third aspect of the present application provides an electronic device, including a memory and a processor, wherein the memory stores a computer program; the processor executes the computer program stored in the memory, so that the electronic device performs the battery detection method described in the first aspect above.

[0024] An embodiment of the fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it is used to implement the battery detection method described in the first aspect above.

[0025] An embodiment of the fifth aspect of the present application provides a computer program product, wherein the computer program product is a computer program, and when the computer program is executed by a processor, it is used to implement the battery detection method described in the first aspect above.

[0026] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0028] Figure 1 A schematic flow chart of a battery detection method according to some embodiments of the present application;

[0029] Figure 2 A schematic diagram of battery formation according to an embodiment of the present application;

[0030] Figure 3 A circuit diagram of a battery during charging according to some embodiments of the present application;

[0031] Figure 4a This is a schematic diagram of the charging principle of a normal battery;

[0032] Figure 4b Schematic diagram of the charging principle of an abnormal battery with an internal short circuit;

[0033] Figure 5 Schematic diagram of the voltage-to-capacity relationship curves of a normal battery and an abnormal battery;

[0034] Figure 6 for Figure 1 A schematic flow chart of a modified example of the method shown;

[0035] Figure 7 A scatter plot of the self-discharge current of a battery under test in a battery testing method according to some embodiments of the present application;

[0036] Figure 8 is the normal distribution diagram of the self-discharge current of the benchmark battery;

[0037] Figure 9 Schematic diagram of formation curve of the tested battery in some embodiments of the present application;

[0038] Figure 10A schematic diagram of the voltage-charging time relationship curve for normal batteries and abnormal batteries;

[0039] Figure 11 Schematic diagram of a flow chart of a battery detection method according to other embodiments of the present application;

[0040] Figure 12 for Figure 11 A schematic flow chart of a modified example of the method shown;

[0041] Figure 13 A schematic diagram of a first relationship curve of a battery according to some embodiments of the present application;

[0042] Figure 14 A schematic flow chart of a battery detection method according to some further embodiments of the present application;

[0043] Figure 15 A schematic structural diagram of a battery detection device according to some embodiments of the present application;

[0044] Figure 16 Schematic diagram of the structure of electronic equipment in some embodiments of the present application. DETAILED DESCRIPTION

[0045] The following embodiments of the technical solution of the present application will 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 application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0047] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0048] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0049] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0050] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0051] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0052] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0053] Power batteries are widely used in mobile devices and electric vehicles. Power batteries need to be tested before leaving the factory to screen out batteries that fail self-discharge, thereby ensuring that all batteries leaving the factory have excellent performance.

[0054] Refer to the following Figure 4a and Figure 4bThe battery cell includes a positive electrode sheet 210, a negative electrode sheet 220, a separator 230 and an electrolyte 240. During the manufacturing process of the battery cell, impurities are mixed into the interior of the battery cell. Some impurities can conduct the positive electrode sheet 210 and the negative electrode sheet 220, thereby causing a short circuit inside the battery cell. In this way, even if the battery is not connected to a load, the short circuit will consume the battery's power, causing the battery's power to decrease. In other words, when a power battery in an open circuit state is left at a certain temperature for a period of time, its power will decrease. This phenomenon is called battery self-discharge. Based on this, although there are many methods for characterizing the self-discharge performance of batteries in the relevant technology, the general idea is to leave the manufactured battery aside for a period of time and monitor the changes in parameters during the battery shelving process.

[0055] For example, taking the K value as an example to illustrate the self-discharge performance of the battery, in the related art, the test steps of the method for detecting the K value of the battery are generally as follows: charging the battery to a fixed capacity C to complete the formation process; letting the formed battery stand for a period of time to age the battery and achieve depolarization; after a time period of t1, the voltage of the battery is tested to be U1, and after a time period of t2, the voltage of the battery is tested to be U2, wherein t1 < t2, U1 < U2; calculating the K value, K value = (U1-U2) / (t2-t1); and then detecting the self-discharge performance of the battery based on the K value to screen out unqualified batteries with severe self-discharge.

[0056] Researchers in this application discovered that testing battery performance often requires leaving the battery for an extended period to measure changes in parameters during discharge. This results in extended battery performance testing times, long test cycles, and low test efficiency. This further poses significant challenges to battery manufacturers' storage space and cash flow.

[0057] In response to the above problems, the researchers of this application have realized that there are also differences in the parameters of normal and abnormal batteries during the charging process. By detecting the parameters of the battery charging process, the performance of the battery can also be tested to detect whether the battery is qualified. Inspired by this technical concept, the researchers of this application finally designed a battery detection method and detection device. This method relies on the charging data of the battery during the formation process to determine whether the battery is normal. Since the formation process is a necessary processing step for each battery, this can make full use of the data during the formation process, eliminating the shelving time, which is conducive to shortening the test time.

[0058] The battery detection method and device disclosed in the embodiments of the present application can be applied to the production and manufacturing process of the battery, and specifically can be applied to the back-end process of battery manufacturing. The battery here is not limited to lithium-ion batteries, but can also refer to other types of batteries such as lead-acid batteries and nickel-cadmium batteries. It should be pointed out that the battery can be used as a power source for electrical devices to power the electrical devices. Among them, the electrical devices can be but are not limited to mobile phones, tablets, laptops, electric toys, power tools, battery cars, electric cars, ships, spacecraft, etc. Electric toys can include fixed or mobile electric toys, for example, game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles and spacecraft, etc.

[0059] The battery detection method provided in the embodiments of the present application may be executed by a battery detection device or an electronic device capable of controlling the battery detection device, such as a server or terminal device. The following embodiments are illustrated using a battery detection device as an example.

[0060] The present application provides a battery testing method for testing whether a battery is functioning properly. Based on the test results, batteries with substandard performance can be screened out. The battery testing method obtains charging data from the battery under test during the formation process and determines whether the battery under test is functioning properly based on the charging data. The battery under test is a newly manufactured battery to be tested, and the model and type of the battery under test are non-restrictive.

[0061] It is worth noting that, since the battery detection method in this embodiment utilizes the charging data of the tested battery during the formation process for testing, the detection method can be implemented after the formation process in the battery manufacturing process.

[0062] The following describes battery detection methods provided by some embodiments of the present application with reference to the accompanying drawings.

[0063] Figure 1 This is a flow chart of a battery detection method according to some embodiments of the present application. Figure 1 In the example shown, the method includes the following steps S101 to S103.

[0064] Step S101 , obtaining charging data of the battery under test during the formation process; the charging data includes a voltage value and a corresponding power value.

[0065] Step S102 : determining a test voltage range and a measured value of the battery under test according to the charging data of the battery under test.

[0066] Step S103: judging whether the tested battery is normal according to the tested value and the standard value.

[0067] The formation process, also known as activation, is the initial charging of newly manufactured, packaged batteries to activate the active materials within them. Only after activation can the battery function properly, making the formation process an essential step in every battery manufacturing process.

[0068] Figure 2 Schematic diagram of the battery 200 of some embodiments of the present application. Figure 2 As shown, the specific implementation of the formation process can be: using the power supply 110 to charge the battery 200 so that the power of the battery 200 reaches a preset power. Specifically, for example, referring to Figure 3 As shown, the battery 200 is equivalent to a capacitor, and the two ends of the capacitor are respectively connected to the positive and negative poles of the power supply 110. A charging circuit 120 is connected between the power supply 110 and the capacitor. The charging circuit 120 can adjust and control the voltage delivered to the capacitor by the power supply 110. When the circuit between the capacitor and the power supply 110 is turned on, current flows through the circuit between the capacitor and the power supply 110, causing the charge of the capacitor to increase continuously. In other words, the voltage value of the battery 200 increases continuously, and accordingly, the charge value of the battery 200 also increases continuously until the voltage value of the battery 200 increases to the same as the voltage value of the power supply 110. Among them, Figure 3 Schematic diagram of a circuit of a battery 200 during charging according to some embodiments of the present application. It should be noted that the power supply 110 can provide a constant current during the formation process to charge the battery 200 at a constant current.

[0069] And, continue to refer to Figure 2 As shown, a detection circuit 130 may be connected between the power supply 110 and the battery 200. Thus, step S101 may obtain charging data by acquiring data detected by the detection circuit 130. In this example, the charging data may include the voltage value U (unit: V) of the battery 200 and the power value Q (unit: mA·h) of the battery 200, as shown in FIG. Figure 3 As shown, the detection circuit 130 in this case may include a voltmeter 131 and a power meter 132. The voltmeter 131 is connected in parallel with the capacitor to detect the voltage value of the capacitor. The power meter 132 uses a coulomb detection method to detect the power value of the battery 200. The resistor R1 is the internal resistance of the power meter 132. Of course, in other embodiments, the voltmeter 131 can also be replaced with other voltage sensors.

[0070] It is understandable that the voltage value U of the battery 200 and the charge value Q of the battery 200 are in one-to-one correspondence. Because the voltage value and charge value of the battery 200 increase with the charging time, the detection circuit 130 can detect multiple sets of charging data during the charging process of the battery 200. In this way, multiple sets of charging data of the tested battery 200 can be obtained in step S101, and each set of charging data can be (U, Q). For example, if the voltage value of the power supply 110 is 4.2V, the charging data obtained for the tested battery can be (2V, 6734.3mA·h), (3.2V, 20038.4mA·h), (4V, 35205.1mA·h), etc.

[0071] Based on step S101, step S102 is to select the first terminal voltage value U from the charging data of the tested battery. C1 and the second terminal voltage value U C2 As the endpoint of the test voltage range, where U C1 C2 , then the test voltage range is (U C1 , U C2 For example, if the voltage value of the power supply 110 is 4.2V, the test voltage range of a tested battery may be (1.8V, 3V), (2V, 3.2V), or (2.5V, 4V). Furthermore, while determining the test voltage range, the measured value can also be determined based on the voltage value U of the battery 200 and the charge value Q of the battery 200.

[0072] The standard value in the step S103 can be understood as the numerical value corresponding to the measured value of reference battery, here, reference battery refers to and is defined as normal battery by test, and the battery that model, type are consistent with tested battery, and reference battery is also identical with the charging parameter (for example charging current or charging voltage) of the formation process with the charging parameter of the formation process of tested battery. Design like this, the purpose of step S103 is to compare the measured value of tested battery with the measured value of reference battery, to judge whether tested battery is normal.

[0073] In summary, by testing the battery under test according to the detection method provided in this embodiment, it is possible to determine whether the battery under test is normal, and further to screen out abnormal batteries.

[0074] ​In the related art, the process flow of battery 200 includes a sealing process, a formation process, a static process, a testing process, and a capacity separation process, that is, the battery 200 is first set aside and then the discharge parameters of the battery 200 are tested to test the performance of the battery 200. However, the present embodiment uses the charging data of the battery 200 in the formation process to determine the performance of the battery 200. Therefore, the detection method provided by the present embodiment can be performed after the formation process and before the static process. With such a design, the performance of the battery 200 can be tested with the help of the charging data of the formation process before the static process and the testing process, so that unqualified batteries 200 can be screened out in advance. In this way, there is no need to set the battery 200 aside for a period of time, which is conducive to shortening the test time and test cycle of the battery 200, improving the test efficiency, and then helping to alleviate the pressure on storage space and cash flow of the battery 200 manufacturer.

[0075] And, because formation process is the processing procedure that each battery 200 must go through, therefore, adopt this detection method to test the performance of battery 200, can make full use of the data of formation process, improved the utilization ratio to the charging data of formation process.In addition, the mode that detects the performance of battery 200 by the mode of shelving often can only carry out random inspection to battery 200, utilize the detection method of present embodiment, each battery 200 can use its charging data in formation process to carry out performance test, and then can realize the effect of battery 200 full inspection, promptly each battery 200 all can carry out performance test, helps to avoid unqualified battery 200 to ship from the factory.

[0076] In one achievable method, the measured value can be the test power difference ΔQ C ; Among them, the test power difference ΔQ C The first endpoint voltage value U of the tested battery in the test voltage range C1 Charge to the second terminal voltage value U C2 The difference in the power value Q.

[0077] Figure 4a This is a schematic diagram of the charging principle of a normal battery. Figure 4b This is a schematic diagram of the charging principle of an abnormal battery with an internal short circuit. Figure 4a As shown, if the battery 200 is normal, when the battery 200 is charged, the lithium ions Li + Move to the negative electrode of the battery through the diaphragm 230, and at the same time, the electrons e - Migrate to the negative electrode of the battery along the charging circuit 120, so that the electrons e - Reduce, negative electron e - Increase, the potential difference is formed between the positive and negative electrodes of the battery, and as the electrons e - As the voltage of the battery 200 increases. Figure 4bAs shown, based on the normal battery charging principle, if the internal short circuit of the battery 200, the positive electrode and the negative electrode of the battery 200 are slightly connected and form a conductive loop 140, which is connected in parallel with the charging circuit 120. The electrons e - Migrate to the negative electrode of the battery along the charging circuit 120, and some of the electrons e - Migrate along the conductive loop 140 to the positive electrode of the battery and embed some lithium ions Li + The battery is then deintercalated and moves through the separator 230 to the positive electrode of the battery. As can be seen, when an abnormal battery experiences an internal short circuit, self-discharge occurs. Therefore, when the abnormal battery 200 is charged, a larger amount of energy is charged into the battery 200 to compensate for the energy loss caused by self-discharge. Therefore, when a normal battery and an abnormal battery are charged to the same voltage, the energy level of the abnormal battery is higher than that of the normal battery.

[0078] Figure 5 The voltage-to-charge relationship curves of normal and abnormal batteries are shown in FIG. The voltage-to-charge relationship curves are obtained by fitting the charging data of the battery 200. The voltage-to-charge relationship curves are used to characterize the relationship between the charge value of the battery 200 and the voltage change. It should be noted that the voltage-to-charge relationship curves of normal batteries can be as follows: Figure 5 As shown by the solid line in the middle, the voltage-to-capacity relationship curve of the abnormal battery can be shown as Figure 5 Indicated by the dotted line. Figure 5 It can be seen that when the voltage value of the normal battery is consistent with the voltage value of the abnormal battery, the power value of the normal battery is less than the power value of the abnormal battery; conversely, when the power value of the normal battery is consistent with the power value of the abnormal battery, the voltage value of the normal battery is greater than the voltage value of the abnormal battery.

[0079] Based on this difference, the voltage value of the tested battery is designed to be quantitative, and the tested value and the standard value are designed to be related to the power value. By comparing the tested value with the standard value, it can be determined whether the tested battery is normal.

[0080] from Figure 5 It can be seen that when charged to the same voltage, the normal battery and the abnormal battery have different power levels. Therefore, in some embodiments, the measured value can specifically be the power level corresponding to the battery being tested when charged to the target voltage value within the test voltage range. In this example, the standard value is the power level corresponding to the reference battery being charged to the target voltage value. If the measured value differs from the standard value, the battery being tested can be considered abnormal. If the measured value is the same as the standard value, the battery being tested can be considered normal.

[0081] The target voltage value can specifically be the first endpoint voltage value, the second endpoint voltage value, or any voltage value between the first endpoint voltage value and the second endpoint voltage value. When the charging data of the battery under test includes (2V, 6734.3mA·h), (3.2V, 20038.4mA·h), and (4V, 35205.1mA·h), and the test voltage range is (2V, 3.2V), if the target voltage value can be the first endpoint voltage value, the measured value can be determined to be 6734.3mA·h. If the target voltage value can be the second endpoint voltage value, the measured value can be determined to be 20038.4mA·h.

[0082] Here, the standard value can be designed based on the charging data of a previously tested and determined reference battery during the formation process. Furthermore, the standard value can be calculated by taking the average of the charge values ​​corresponding to the target voltage value of multiple reference batteries. In this way, the standard value is designed based on the charging data of multiple reference batteries, thereby improving the accuracy of the test.

[0083] from Figure 5 It can be seen that by U C1 Charge to USB C2 When the normal battery power difference ΔQ 正 The difference in charge between the battery and the abnormal battery ΔQ 异 Therefore, in some embodiments, the measured value can be the test power difference ΔQ C , test power difference ΔQ C The first endpoint voltage value U of the tested battery in the test voltage range C1 Charge to the second terminal voltage value U C2 The difference in the power value Q, that is, the test power difference ΔQ C Equivalent to the battery being tested being charged to U C2 The corresponding power value Q C2 Subtract charge to U C1 The corresponding power value Q C1 In this example, the standard value is the standard power difference ΔQ B , standard power difference ΔQ B For the base battery by U C1 Charge to USB C2 The standard deviation of the power value Q at the time of testing is as follows. With such a design, the battery detection method in this embodiment is to compare the first terminal voltage value U of the tested battery with the first terminal voltage value U C1 Charge to the second terminal voltage value U C2 The power difference ΔQ C The difference between the standard power and ΔQ B , in order to judge whether the tested battery is normal. C =ΔQ B , the tested battery can be considered normal; when ΔQ C ≠ΔQB , it can be considered that the tested battery is abnormal.

[0084] For example, when the charging data of the tested battery include (2V, 6734.3mA·h), (3.2V, 20038.4mA·h), (4V, 35205.1mA·h), if the test voltage interval is determined to be (2V, 3.2V), then the test power difference ΔQ C =20038.4mA·h-6734.3mA·h=13304.1mA·h.

[0085] Among them, the standard power difference ΔQ B It can be designed based on experience and actual working conditions. For example, when the test voltage range is (2V, 3.2V), the standard power difference ΔQ B The current can be designed to be 13304.1 mA·h, 13600 mA·h, 14000 mA·h, etc., and this embodiment does not impose any limitation thereto.

[0086] Since the positive and negative electrodes of the internal short circuit are conductive, the abnormal battery has a self-discharge phenomenon. Therefore, the amount of electricity charged into the abnormal battery must be greater than the amount of electricity charged into the normal battery to compensate for part of the self-discharge of the abnormal battery. Therefore, the detection method of this embodiment uses the charging data of the battery under test in the formation process to calculate the test electricity difference of the battery under test. Based on the test electricity difference and the standard electricity difference, it can be determined whether the battery under test is different from the reference battery, and then unqualified batteries under test can be screened out.

[0087] And, the normal battery is made of U C1 Charge to USB C2 The difference in power between the battery and the abnormal battery is determined by U C1 Charge to USB C2 The difference in the power difference is large. In this embodiment, the measured value is designed to be the test power difference. Compared with directly designing the measured value to be the power value corresponding to the tested battery being charged to the target voltage value, it is beneficial to avoid misjudgment and improve the accuracy of battery testing.

[0088] In another achievable manner, the measured value may be the total charging current I of the battery under test. 测总 The total charging current refers to the total current in the circuit between the battery and the power source 110 during the charging process.

[0089] Understandably, continue to refer to Figure 4a As shown, during normal battery charging, the lithium ion Li + Move to the negative electrode of the battery through the diaphragm 230, converting electrical energy into chemical energy. At the same time, the electrons e -Migrates along the charging circuit 120 to the negative electrode of the battery, so that a chemical current I is formed in the circuit between the battery and the power source 110. 化学 , at this time I 化学 That is the total charging current I of a normal battery 总 . Continue to refer to Figure 4b As shown, when the abnormal battery is charged, due to the short circuit inside the battery, the positive and negative electrodes of the battery are slightly connected to form a conductive loop 140. The conductive loop 140 is connected in parallel with the charging circuit 120. The positive electrode sheet 210, the negative electrode sheet 220 and the electrolyte 240 have internal resistance. Therefore, the conductive loop 140 can be regarded as a resistor R2 connected in series. The electrons e of the positive electrode of the battery - Migrating from the positive electrode of the battery to the negative electrode of the battery along the charging circuit 120 to form a chemical current I 化学 , part of the electrons e at the negative electrode of the battery - Migrates to the positive electrode of the battery along the conductive loop 140, and a self-discharge current I is formed on the conductive loop 140. 自放电 Since the conducting loop 140 is connected in parallel with the charging circuit 120, the total charging current of the abnormal battery I 总 Equal to I 化学 with I 自放电 The sum of the self-discharge current I 自放电 It can be understood as the current input by the power supply 110 to compensate for the power consumed by the self-discharge of the battery.

[0090] That is to say, on the basis of the same model and category, the total charging current I of a normal battery is 总 Total charging current of abnormal battery I 总 Based on this difference, this embodiment designs the measured value to be the total charging current I of the tested battery. 测总 By comparing the measured value with the standard value, it can also be determined whether the tested battery is normal. It should be understood that in this example, the standard value can be the total charging current I 标总 .

[0091] According to I=Q / t, the measured value (i.e. the total charging current I of the measured battery) is determined in this embodiment. 测总 ) method is: I 测总 =ΔQ C / ΔT C , where ΔQ C The calculation can be performed by referring to the method described above, which will not be described in detail in this embodiment. C Refers to the voltage value of the first terminal of the battery under test, U C1 Charge to the second terminal voltage value U C2 The required charging time.

[0092] In determining the measured value I 测总 After that, compare the measured value I测总 Compared with the standard value I 标总 , if the measured value I 测总 Compared with the standard value I 标总 If the measured value I 测总 Compared with the standard value I 标总 If they are inconsistent, the battery under test is judged to be abnormal.

[0093] The detection method of this embodiment uses the charging data of the tested battery during the formation process to calculate the total charging current of the tested battery. Based on the total charging current of the tested battery and the total charging current of a reference battery, it is possible to determine whether the tested battery differs from the reference battery, thereby screening out unqualified tested batteries. Compared to using the difference in charge to detect battery quality, the total charging current of the tested battery is more representative of the short circuit condition within the tested battery, resulting in better detection results.

[0094] Figure 6 for Figure 1 The flowchart of the modified example of the method shown is as follows. Figure 6 As shown, when the measured value is the total charging current I 测总 When , step S103 may include the following implementation steps:

[0095] S1031, calculating the self-discharge current of the battery under test based on the measured value and the standard value.

[0096] S1032 : Compare the self-discharge current of the battery under test with the self-discharge current threshold to obtain a comparison result, and determine whether the battery under test is normal based on the comparison result.

[0097] Combined with the above, we can know that on the basis of the same model and category, the total charging current I of a normal battery is 总 Total charging current of abnormal battery I 总 Moreover, when the normal battery and the abnormal battery have the same model and category, the chemical current I generated by the conversion of electrical energy into chemical energy during charging of the normal battery is 化学 The chemical current I formed by the conversion of electrical energy into chemical energy when the abnormal battery is charged 化学 Therefore, the total charging current of the normal battery is I 总 Total charging current of abnormal battery I 总 The difference is the self-discharge current I 自放电 Therefore, this embodiment calculates the self-discharge current I of the battery under test. C自放电 , compare the self-discharge current I of the battery under test C自放电 The self-discharge current threshold can also be used to determine whether the battery under test is normal.

[0098] In step S1031, the standard value is the total charging current I标总 , the reference battery is a normal battery, and its self-discharge current can be regarded as 0mA, so the total charging current of the reference battery is I 标总 =Equal to the chemical current of the reference battery. Since the reference battery and the battery under test are of the same model and type, the chemical current of the battery under test is equal to the chemical current of the reference battery. In general, the standard value = the total charging current I of the reference battery 标总 = Chemical current of the reference battery = Chemical current of the battery under test. According to the total charging current I 总 Equal to I 化学 with I 自放电 The sum of the self-discharge current of the tested battery I C自放电 The calculation formula is: C自放电 =I 测总 -I 标总 .

[0099] The self-discharge current threshold in step S1032 can be understood as the self-discharge current I of the reference battery. B自放电 When the comparison result is the self-discharge current I C自放电 Equal to the self-discharge current threshold I B自放电 , it can be judged that the tested battery is normal. When the comparison result is the self-discharge current I C自放电 Not equal to the self-discharge current threshold I B自放电 , it can be determined that the tested battery is abnormal.

[0100] For example, in some embodiments, the reference battery can be regarded as having a self-discharge current of 0 mA, and the self-discharge current threshold can be designed to be 0 mA. In this embodiment, if the self-discharge current I of the battery under test is calculated C自放电 If the self-discharge current I of the battery under test is calculated, it can be judged that the battery under test is normal. C自放电 If it is not 0mA, it can be determined that the battery under test is abnormal.

[0101] The detection method of this embodiment can be used to detect whether the performance of the tested battery is qualified, especially suitable for detecting whether the self-discharge performance of the tested battery is qualified. In addition, the detection method is to calculate the self-discharge current I of the tested battery. C自放电 Based on this, unqualified batteries can be screened out. In this way, it is possible to intuitively understand whether the tested battery has self-discharge phenomenon and detect whether the self-discharge of the tested battery is serious. In addition, the self-discharge current I of the tested battery is calculated. C自放电 Finally, combined with the formula Q=I×t, the power consumption of the tested battery after being left for a period of time can be calculated, and then the self-discharge rate of the tested battery can be confirmed. The self-discharge rate of the tested battery can be used to define the specifications of the tested battery.

[0102] In addition to setting the self-discharge current threshold to be equal to 0 mA, the self-discharge current threshold can also be determined in other ways. Figure 6 As shown, after step S1031 and before step S1032, the battery detection method of this embodiment may further include:

[0103] Step S104: obtaining the self-discharge currents of the multiple batteries under test.

[0104] Step S105 : determining a self-discharge current threshold value according to the distribution of the self-discharge currents of the plurality of tested batteries.

[0105] Based on step S1031, step S104 can obtain the self-discharge current I of multiple batteries under test. C自放电 It should be noted that, due to the inevitable presence of impurities in the battery manufacturing process, normal batteries generally have a slight self-discharge phenomenon. In the detection method of this embodiment, since the self-discharge current I C自放电 It is not measured directly by the detection instrument, but is based on the total charging current I of the battery being tested. 测总 Compared with the standard value I 标总 The difference is calculated, where the standard value I 标总 It is only used as a reference value. The actual calculated total charging current of the tested battery is I 测总 May be higher than the standard value I 标总 , may also be lower than or equal to the standard value I 标总 Therefore, the calculated self-discharge current I of the tested battery is C自放电 It may be greater than 0mA, or less than or equal to 0mA.

[0106] In step S105, the self-discharge current I of the plurality of batteries under test may be counted. C自放电 and the battery number, and draw a distribution diagram of the self-discharge current of the tested battery, for example, see Figure 7 , Figure 7 This is a scatter plot of the self-discharge current of the battery under test in the battery detection method of some embodiments of the present application. The self-discharge current of the reference battery can be regarded as 0mA. Figure 7 It can be seen that the self-discharge current I of most of the tested batteries C自放电 Scattered around 0mA, the self-discharge current I of a small number of tested batteries C自放电 Much greater than 0mA. Figure 7 The self-discharge current I C自放电 The point exceeding 1A is a discrete point, so the self-discharge current I C自放电 The battery under test that exceeds 1A is an abnormal battery.

[0107] In other embodiments of the present application, the self-discharge current I of the battery under test can be used to determine the self-discharge current of the battery under test. C自放电 The value and frequency of the self-discharge current are plotted as a normal distribution curve. Combined with the 3σ principle, the self-discharge current I can be determined when the tested battery is a normal battery. C自放电 The basic distribution is between [0-3σ, 0+3σ], where σ refers to the standard deviation. C自放电 The range is 0-3σ≤I C自放电 When ≤0+3σ, the tested battery can be judged to be a normal battery. C自放电 The range is I C自放电 <0-3σ or I C自放电 When >0+3σ, the tested battery can be judged as an abnormal battery.

[0108] Determine the self-discharge current I of the battery under test C自放电 The specific implementation method of whether it is between [0-3σ, 0+3σ] can refer to the following example:

[0109] In a possible example, the self-discharge current threshold can be designed to be 0 mA. In this example, the specific implementation of step S1032 is: the self-discharge current I C自放电 Compared with 0mA, the comparison result is I C自放电 , and then according to I C自放电 Whether the tested battery is normal is determined by whether the absolute value is less than or equal to 3σ.

[0110] In another possible example, the self-discharge current threshold may include a first critical value and a second critical value, wherein the first critical value is -3σ (unit: mA) and the second critical value is 3σ (unit: mA). In this example, step S1032 may be implemented using the following steps:

[0111] Step 1: The self-discharge current I C自放电 Compared with the first critical value -3σ, the first comparison result is the difference Δd1=I C自放电 +3σ;

[0112] Step 2: The self-discharge current I C自放电 Compared with the second critical value +3σ, the second comparison result is the difference Δd2=I C自放电 -3σ;

[0113] Step 3: When the first comparison result Δd1 is greater than 0 and the second comparison result Δd2 is less than 0, it is determined that the tested battery is a normal battery.

[0114] Due to the influence of the battery production process, the performance of each battery varies. Therefore, even if all batteries are normal, the self-discharge current of each battery may not be completely consistent. This embodiment determines the self-discharge current threshold based on the distribution of the self-discharge current of the tested battery. In this way, by comparing the self-discharge current of the tested battery with the self-discharge current threshold, it can be determined whether the self-discharge performance of the tested battery is normal. Combined with the above, it can be seen that the value of the self-discharge current used to evaluate battery performance can be a range, rather than a single value, which is conducive to improving the accuracy and rationality of battery screening.

[0115] For example, continue to refer to Figure 6 As shown, after step S1032, the battery detection method of this embodiment may further include:

[0116] Step S106 , correcting the self-discharge current threshold according to the self-discharge current of the reference battery.

[0117] Figure 8 The implementation of step S106 may be as follows: obtaining the self-discharge currents of multiple reference batteries, counting the intervals where the self-discharge currents of the reference batteries are located and the frequency of occurrence of each interval, and establishing a normal distribution diagram (e.g. Figure 8 The horizontal axis of the normal distribution graph represents the self-discharge current intervals of the reference battery, and the vertical axis represents the frequency of each interval. The self-discharge current threshold is designed based on the distribution of the self-discharge currents of the reference battery. For example, the self-discharge current threshold can be designed to be the self-discharge current of the reference battery that occurs most frequently.

[0118] Among them, the specific implementation method of obtaining the self-discharge current of multiple reference batteries can refer to the above-mentioned step S1031. It should be understood that before obtaining the self-discharge current of multiple reference batteries, it is necessary to first determine the reference battery. The reference battery refers to a battery that has passed the test and is determined to be a normal battery, and the model and type are consistent with the battery under test. Here, it is worth pointing out that the reference battery can be determined by testing the K value or self-discharge rate of the battery using the method in the relevant technology. Taking the K value of the test battery to determine the reference battery as an example, the K value of the battery is first tested, and the normal batteries are screened out according to the K value. The part of the normal batteries that are screened out and have the same model and type as the battery under test is used as the reference battery, and then the self-discharge current of the reference battery is calculated based on the charging data of the reference battery in the formation process and the self-discharge current threshold is corrected accordingly.

[0119] Because the methods for testing K values ​​or self-discharge rates are relatively mature, and batteries require a period of rest before their K values ​​or self-discharge rates can be determined, using this method to screen normal batteries is highly accurate. In other words, the purpose of step S106 can be understood as using a known, highly accurate method to screen reference batteries, then using the detection method of this embodiment to calculate the self-discharge current of the reference batteries, and then correcting the self-discharge current threshold based on the self-discharge current of the reference batteries. This allows for highly accurate screening of reference batteries, helps reduce the impact of design errors in the self-discharge current threshold on the test results of the tested batteries, and improves the accuracy of the tested battery testing.

[0120] With this design, the self-discharge current threshold is designed not only by considering the distribution of the self-discharge current of the battery under test, but also by considering the self-discharge current of the reference battery, so as to improve the accuracy of the self-discharge current threshold. Based on the comparison results, it is possible to accurately determine whether the battery under test is a normal battery or an abnormal battery, thereby reducing the error in battery screening.

[0121] When the measured value is the total charging current of the measured battery I 测总 The standard value is the total charging current I of the reference battery. 标总 When, such as Figure 6 As shown, before executing step S1031, the battery detection method may further perform the following steps:

[0122] Step 1: Obtain charging data of a reference battery during a formation process.

[0123] Step 2: Calculate the standard value based on the test voltage range and the charging data of the reference battery.

[0124] In this embodiment, according to I=Q / t, the calculation formula of the standard value is I 标总 =ΔQ B / ΔT B .

[0125] The above standard power difference ΔQ B For batteries powered by U C1 Charge to USB C2 In a preferred example, the reference battery is a normal battery, so the reference battery is U C1 Charge to USB C2 The difference in the power value Q can be regarded as the standard power difference, that is, the standard power difference ΔQ B It can be designed to be equal to the reference battery charged to the second terminal voltage value U C2 The corresponding power value Q B1 Subtract the reference battery charging to the first terminal voltage value U C1 The corresponding power value Q B2 , then ΔQ B =QB2 -Q B1 The charge value of the reference battery can be obtained in step 1. The specific acquisition method is similar to that of the tested battery and can also be detected by the detection circuit 130. In this way, multiple sets of charging data of the reference battery can be obtained in step 1, and each set of charging data is (U, Q).

[0126] Where, ΔT B Refers to the normal battery from the first endpoint voltage value U of the test voltage interval C1 Charge to the second terminal voltage value U C2 The required standard charging time. ΔT B It can be designed based on experience and actual working conditions. For example, when the test voltage range is (2V, 3.2V), ΔT B It can be designed to be 0.8h, 0.82h, 0.85h, 1h, etc., and this embodiment does not impose any limitation on this.

[0127] In some embodiments, since the reference battery is a normal battery, the reference battery is C1 Charge to USB C2 The difference in charging time can be regarded as the standard charging time ΔT B In this example, in addition to the voltage value and the corresponding power value, the detection circuit 130 is also configured to detect the charging time T (unit: h) required for the battery to charge to a certain voltage value. At this time, the charging data of the tested battery and the charging data of the reference battery obtained are both (T, U, Q). In this way, the standard charging time ΔT can be determined based on the charging data of the reference battery in the formation process. B The detection circuit 130 may include a clock chip, which is used to measure the charging time of the battery.

[0128] Exemplarily, the charging data of the reference battery is obtained as shown in Table 1.

[0129] Table 1

[0130]

[0131] Table 1 shows the charging data of battery A and battery B. The following is an example of a test voltage range of (2V, 3.2V). The charging time required for battery A to charge from 2V to 3.2V is 1.82h-1h=0.82h, so ΔT B It can be designed to be 0.82h. For example, when battery A is used as the reference battery, the standard power difference ΔQ can be calculated. B =20038.4mA·h-6734.3mA·h=13304.1mA·h, so the total charging current of the reference battery I 标总 =ΔQ B÷ΔT B =13304.1mA·h÷0.82h=16.224mA, so the standard value is 16.224mA. For another example, when battery B is used as the reference battery, the standard capacity difference ΔQ can be calculated. B =20318.5mA·h-7073.4mA·h=13245.1mA·h, so the total charging current of the reference battery I 标总 =ΔQ B ÷ΔT B =13245.1mA·h÷0.82h=16.152mA.

[0132] It is understood that the standard value can also be the average of the total charging currents of multiple reference batteries. For example, battery A and battery B can both serve as reference batteries. In this case, the standard value can be the average of the total charging currents of battery A and battery B, and the standard value is (16.224mA + 16.152mA) / 2 = 16.188mA. Compared to taking the total charging current of a single reference battery as the standard value, in this embodiment, the average of the total charging currents of multiple reference batteries is used as the standard value. This helps reduce the impact of errors in the total charging current of the reference battery on the test, thereby improving test accuracy.

[0133] Compared with designing a fixed standard value based on past experience, the detection method of this embodiment calculates the standard value based on the actual charging data of the reference battery during the formation process. In this way, the standard value is less likely to have errors and is reasonably designed.

[0134] It is worth noting that when the detection circuit 130 can detect the charging time of the battery and the charging data includes the charging time, ΔT c It can be calculated based on the charging data of the tested battery obtained in step S101. At this time, ΔT c The charging time T2 required for the tested battery to be charged to the second endpoint voltage value may be subtracted from the charging time T1 required for the tested battery to be charged to the first endpoint voltage value.

[0135] Alternatively, in other feasible embodiments, ΔT C Can be equal to ΔT B , then the measured value is the total charging current I of the battery under test 测总 When I 测总 =ΔQ C / ΔT C =ΔQ C / ΔT BWith this design, the total charging current of the battery under test is calculated based on the standard time required for a normal battery to charge from a first endpoint voltage value to a second endpoint voltage value. This eliminates the need to calculate the charging time required for the battery under test to charge from a first endpoint voltage value to a second endpoint voltage value, thus saving computational effort.

[0136] If it is assumed that the average value of the total charging current of battery A and battery B shown in Table 1 is the standard value, that is, the standard value is 16.188mA·h, and the test voltage range is (2V, 3.2V), ΔT c When the test power difference of the tested battery is shown in Table 2, the total charging current and self-discharge current of the tested battery can be measured according to the above description.

[0137] Table 2

[0138]

[0139] Taking the self-discharge current threshold as 0mA as an example, at this time, the self-discharge current I of the tested battery 1 in Table 2 is C自放电 If the self-discharge current threshold is not equal to the self-discharge current threshold, the tested battery is judged to be abnormal, that is, an unqualified battery; similarly, the self-discharge current I C自放电 If the value is not equal to the self-discharge current threshold, the tested battery is judged to be abnormal and is also an unqualified battery.

[0140] The method for determining the test voltage range of the battery under test according to the charging data of the battery under test in step S102 specifically includes the following steps:

[0141] Step 1021 , performing fitting based on the charging data of the battery under test to generate a formation curve of the battery under test; the formation curve includes a voltage value and a corresponding power value of the battery under test.

[0142] Step 1022 : Determine the test voltage range according to the slope of each point on the formation curve of the battery under test.

[0143] Step S101 can obtain multiple sets of charging data of the tested battery, each set of charging data is (U, Q), and step S1021 can obtain the formation curve of the tested battery by fitting the multiple sets of charging data. For example, the charging data of the tested battery can be fitted to obtain Figure 9 The vertical axis of the formation curve represents the voltage value of the battery under test, and the horizontal axis of the formation curve represents the charge value of the battery under test. Figure 9This is a schematic diagram of the formation curve of the battery under test in some embodiments of the present application. It can be seen from the formation curve that during the charging process of the battery under test, the voltage value of the battery under test is positively correlated with the power value. In addition, when the voltage value of the measured voltage is in the range of 2V to 3.2V, the tangent slope of each point on the curve segment ab is greater than or equal to k1; when the voltage value of the measured voltage is in the range of 3.6V to 4V, the tangent slope of each point on the curve segment cd is greater than or equal to k2; when the voltage value of the measured voltage is in the range of 3.2V to 3.6V, the tangent slope of each point on the curve segment bc is greater than or equal to 0 and less than k1 and k2. This means that when the voltage value of the measured voltage is in the range of 2V to 3.2V and in the range of 3.6V to 4V, the voltage value increases rapidly, and when the voltage value of the measured voltage is in the range of 3.2V to 3.6V, the voltage value increases slowly. Thus, the curve segment ab can be regarded as the first non-plateau region of the formation curve, the curve segment bc can be regarded as the plateau region of the formation curve, and the curve segment cd can be regarded as the second non-plateau region of the formation curve.

[0144] In this way, the specific implementation of step S1022 can be to divide the formation curve into a plateau area and a non-plateau area according to the slope of each point on the formation curve of the tested battery, determine the voltage range corresponding to the plateau area as the test voltage interval, or determine the voltage range corresponding to the non-plateau area as the test voltage interval. The above-mentioned division of the formation curve into the plateau area and the non-plateau area according to the slope of each point on the formation curve includes but is not limited to the following possible implementations:

[0145] In one example, a formation function U=f(Q) is constructed based on the formation curve. The formation function is used to characterize the formation curve. The first-order derivative of the formation function is taken to obtain the first-order derivative function U=f'(Q). The charging data corresponding to each point in the formation curve is substituted into the first-order derivative function U=f'(Q) to obtain the first-order derivative of each point. In this way, the point with the first-order derivative greater than or equal to k1 and the minimum voltage value is determined as the starting endpoint of the first non-plateau region, and the point with the first-order derivative greater than or equal to k1 and the maximum voltage value is determined as the ending endpoint of the first non-plateau region. The first non-plateau region can be determined. The point with the first-order derivative greater than or equal to k2 and the minimum voltage value is determined as the starting endpoint of the second non-plateau region, and the point with the first-order derivative greater than or equal to k2 and the maximum voltage value is determined as the ending endpoint of the second non-plateau region. The second non-plateau region can be determined. Wherein, the ending endpoint of the first non-plateau region is the starting endpoint of the plateau region, and the starting endpoint of the second non-plateau region is the ending endpoint of the plateau region. The plateau region can be determined.

[0146] Alternatively, in another example, a formation function U=f(Q) is constructed based on the formation curve, and the formation function is used to characterize the formation curve. The first-order derivative of the formation function is obtained by taking the first-order derivative U=f'(Q). The charging data of the tested battery are arranged in order from small to large voltage values ​​and substituted into the first-order derivative function U=f'(Q), and then a first-order derivative sequence can be obtained. The point where the first-order derivative changes from greater than or equal to k1 to greater than 0 but less than k1 and k2 is determined as the starting endpoint of the platform area, and the point where the first-order derivative changes from greater than 0 but less than k1 and k2 to greater than or equal to k2 is determined as the ending endpoint of the platform area. The platform area can be determined, and then the first non-platform area and the second non-platform area can be determined.

[0147] The first-order derivative of each point in the above-mentioned formation curve represents the slope of the tangent line at that point. In this way, the detection method can divide the plateau area and the non-plateau area by calculating the first-order derivative.

[0148] In the first example, the voltage range corresponding to the non-platform area can be determined as the test voltage range. Figure 9 As shown, the test voltage interval of the battery under test can be (2V, 3.2V) or (3.6V, 4V). Moreover, it is understandable that in some embodiments, the test voltage interval of the battery under test can be further designed to be included in the voltage range corresponding to the non-plateau area. For example, the test voltage interval of the battery under test can be (2.2V, 3V), (3.8V, 4V), etc.

[0149] In the second example, the voltage range corresponding to the platform area can be determined as the test voltage range. Figure 9 As shown, the test voltage interval of the battery under test can be (3.2V, 3.6V). Moreover, it is understandable that in some embodiments, the test voltage interval of the battery under test can be further designed to be included in the voltage range corresponding to the platform area. For example, the test voltage interval of the battery under test can be (3.3V, 3.5V).

[0150] Compared with designing the voltage range corresponding to the platform area as the test voltage interval, in the first example, the voltage range corresponding to the non-platform area is designed as the test voltage interval. When the power difference is the same, the voltage difference corresponding to the non-platform area is larger, so the difference between the first endpoint voltage value and the second endpoint voltage value of the test voltage interval can be larger, which is convenient for calculation.

[0151] It should be noted that for the same model of tested batteries, after obtaining the test voltage range in step S102 based on the charging data of one of the tested batteries, the test voltage range can be used as a reference when detecting other tested batteries using the method of this embodiment, and step S102 can be omitted.

[0152] The battery detection method of this embodiment establishes a formation curve based on the charging data of the tested battery, and determines the test voltage range according to the change of the slope of each point on the formation curve, which fully considers the changing characteristics of the formation curve and is conducive to improving the test accuracy.

[0153] Of course, in other embodiments of the present application, two voltage values ​​in the charging data of the tested battery may be arbitrarily selected as the endpoint voltage values ​​of the test voltage interval to further determine the test voltage interval of the tested battery.

[0154] It is worth noting that, referring to the detection method of this embodiment, using the charging data of the formation process to test the self-discharge current of the battery, and then detecting whether the battery is normal, has been verified by a large number of experiments. Specifically, since the self-discharge caused by an internal short circuit in the battery is equivalent to the discharge caused by the battery series resistance, the experimental plan is to charge the unformed battery using the detection method of this embodiment and record the charging data, and detect the self-discharge current when the battery is not connected in series with a resistor and the self-discharge current when the resistor is connected in series. Based on the difference between the self-discharge current when the battery is not connected in series with a resistor and the self-discharge current when the resistor is connected in series, it is proved that the self-discharge current when the battery is connected in series with a resistor is different from the self-discharge current when the battery is not connected in series with a resistor. Therefore, based on the self-discharge current of the battery, it can be judged whether the battery is normal.

[0155] Specifically, reference may be made to Table 3, which shows charging data for three experimental batteries. None of the three experimental batteries were formed. Among the three experimental batteries, the S1 battery had no series resistor, the S2 battery had a series resistor with a resistance of 100K, and the S3 battery had a series resistor with a resistance of 1M. The S1 battery, the S2 battery, and the S3 battery were charged for formation, wherein the test voltage range was (2V, 3.2V), and the charging time required for the three experimental batteries to charge from 2V to 3.2V was 0.87167h. The self-discharge currents of the three experimental batteries were calculated as shown in Table 3.

[0156] Table 3

[0157] Battery serial number Battery series resistance status Test power difference ΔQ <![CDATA[Total charging current I 总 > <![CDATA[Self-discharge current I 自放电 > S1 Battery No series resistor 200.38 229.88 0 S2 Battery A 100K resistor in series 200.77 230.33 0.45 S3 Battery A resistor with a resistance of 1M is connected in series 200.5 230.02 0.14

[0158] As can be seen from Table 3, the S1 battery has no series resistor, which is equivalent to a normal battery with no internal short circuit. Therefore, the S1 battery can be used as a reference battery to calculate the self-discharge current I of the S2 battery. 自放电 =230.33-229.88=0.45, it can be seen that the self-discharge current of the S2 battery with a 100K resistor in series is not equal to the self-discharge current of the S1 battery. Similarly, the self-discharge current of the S3 battery with a 1M resistor in series is also not equal to the self-discharge current of the S1 battery.

[0159] The following describes battery detection methods provided in other embodiments of the present application with reference to the accompanying drawings.

[0160] Figure 10 The figure is a schematic diagram of the voltage-charging time relationship curve of normal batteries and abnormal batteries. Figure 4a and Figure 4b It can be seen that the abnormal battery has an internal short circuit, the positive and negative electrodes of the abnormal battery are connected to form a conductive loop 140, and the electrons e at the negative electrode of the battery - It will migrate to the positive electrode along the conductive loop 140, causing self-discharge. Affected by self-discharge, the abnormal battery charges more slowly than the normal battery at the same current, and the charging time required to reach a certain voltage value is longer. Therefore, the relationship between the voltage and charging time of a normal battery is as follows: Figure 10 The solid line shows the relationship between the voltage and charging time during abnormal battery charging. Figure 10 Based on this difference, this embodiment compares the relationship between the voltage and charging time of the tested battery with that of the reference battery to determine whether the tested battery is normal. This embodiment is described in detail below with reference to the accompanying drawings.

[0161] Figure 11 This is a flow chart of a battery detection method according to some other embodiments of the present application. Figure 11 In the example shown, the method includes the following steps S201 to S203.

[0162] Step S201, obtaining charging data of the battery under test during the formation process; the charging data includes a reference parameter and a parameter to be measured, wherein one of the reference parameter and the parameter to be measured is a voltage value, and the other is a charging time required to charge to the corresponding voltage value.

[0163] Step S202 : determining, based on the charging data of the battery under test, the parameter value of the parameter to be tested of the battery under test when the reference parameter is in the interval to be estimated.

[0164] Step S203 , judging whether the battery under test is normal based on a comparison result between the parameter value of the battery under test when the reference parameter is in the estimated interval and the benchmark reference value.

[0165] and Figure 1 Similar to step S101 in the detection method shown, the detection method of this embodiment also detects whether the tested battery is normal based on the charging data of the tested battery during the formation process. Specifically, the charging data obtained in step S201 in this example may include the battery voltage value U (unit: V) and the charging time T (unit: h) required for the battery to charge to a certain voltage value. At this time, the detection circuit 130 may include a voltmeter 131 and a clock chip. The voltmeter 131 is connected in parallel with the battery to detect the battery voltage value, and the clock chip is used for timing.

[0166] It is understood that the battery voltage value U and the corresponding charging time T are one-to-one corresponding. Because the battery voltage value increases with the charging time, the detection circuit 130 can detect multiple sets of charging data during the battery charging process. In this way, multiple sets of charging data of the tested battery can be obtained in step S201, and each set of charging data can be (T, U). For example, if the voltage value of the power supply 110 is 4.2V, the charging data obtained for a tested battery may be (1h, 1.8V), (1.6h, 2.8V), and (2h, 3.2V).

[0167] After obtaining charging data, using one of voltage value and charging duration as reference parameter, the other as parameter to be measured, determine the numerical value of the parameter to be measured when the reference parameter is in the measured interval, then compare the parameter value of the parameter to be measured with the benchmark reference value.Here, the benchmark reference value can be understood as the numerical value of the parameter to be measured when the reference parameter is in the measured interval.Wherein, the model and type of the benchmark battery are consistent with the measured battery, and the benchmark battery is a normal battery, and the charging parameter (such as charging current or charging voltage) of the benchmark battery in the formation process is consistent with the charging parameter of the measured battery in the formation process.Like this, by comparing the parameter value and the benchmark reference value of the parameter to be measured, it can be judged that the parameter value of the parameter to be measured of the measured battery is different from the benchmark battery, if the parameter value of the parameter to be measured of the measured battery is different from the benchmark battery, then it can be judged that the measured battery is normal.

[0168] In summary, by testing a battery under test using the detection method provided in this embodiment, it is possible to determine whether the battery under test is normal, thereby screening out abnormal batteries. Furthermore, because abnormal batteries exhibiting self-discharge require a longer charging time to a certain voltage value than normal batteries, the detection method provided in this embodiment can be used to detect whether the self-discharge performance of the battery under test is acceptable by comparing the relationship between the voltage value and charging time of the battery under test with the relationship between the voltage value and charging time of a reference battery.

[0169] The process flow of batteries in the related art includes a sealing process, a formation process, a static process, a testing process, and a capacity separation process, that is, the battery is first shelved and then the discharge parameters of the battery are detected to test the battery performance. However, the present embodiment uses the charging data of the battery in the formation process to judge the performance of the battery. Therefore, the detection method provided by the present embodiment can be performed after the formation process and before the static process. With such a design, the performance of the battery can be tested with the help of the charging data of the formation process before the static process and the testing process, so that unqualified batteries can be screened out in advance. In this way, there is no need to shelve the battery for a period of time, which is conducive to shortening the test time and test cycle of the battery, improving the test efficiency, and then helping to alleviate the pressure on the storage space and cash flow of the battery manufacturer.

[0170] And, because the formation process is the necessary processing procedure for each battery, therefore, adopting this detection method to test the performance of the battery, can make full use of the data of the formation process, improved the utilization rate of the charging data of the formation process. In addition, the mode of detecting the performance of the battery by the mode of shelving often can only carry out random inspection to the battery, utilize the detection method of the present embodiment, each battery can use its charging data in the formation process to carry out performance test, and then can realize the effect of full inspection of the battery, namely each battery all can carry out performance test, is conducive to avoiding unqualified battery to leave the factory.

[0171] In a feasible embodiment, the reference parameter can be the voltage value of the interval to be estimated, and the parameter to be measured is the charging time required to charge to the corresponding voltage value. In this case, the reference value is the charging time required for the reference battery to charge to the corresponding voltage value. The meaning of this embodiment is to compare the charging time required for the tested battery and the reference battery to charge to the same voltage value under the same charging parameters. Among them, the interval to be estimated can be (U d1 , U d2 ), and U d1 Less than U d2 Thus, the method of this embodiment utilizes the charging data of the battery under test during the constant current charging phase for testing, and thus has high detection accuracy.

[0172] For example, the reference parameter could be U d1 , then the parameter to be measured is the battery being tested charged to U d1 Required charging time T d1 Here, the reference value can be designed based on experience and actual working conditions. Preferably, the reference value can be the reference battery charged to U d1 Required charging time T J1 , according to T d1 With T J1 The comparison result of T is used to determine whether the tested battery is normal. d1 With T J1The comparison result of T is used to determine whether the tested battery is normal. There are the following possible situations: In the first situation, if the comparison result is T d1 =T J1 , then the battery under test is normal. If the comparison result is T d1 ≠T J1 , then the tested battery is judged to be abnormal; in the second case, if the comparison result is T d1 With T J1 If the difference between the two values ​​is within the preset range, the battery under test is considered normal. d1 With T J1 If the difference between the two exceeds the preset range, the battery under test is judged to be abnormal. d1 Required charging time T d1 The battery is qualified if it is in a certain time range. d1 Comparison with a numerical value helps reduce detection bias and inaccurate testing.

[0173] For another example, the reference parameter can be U d2 , then the parameter to be measured is the battery being tested charged to U d2 Required charging time T d2 Alternatively, the reference parameter may be any voltage value within the range to be estimated. Of course, in some embodiments, there may be multiple reference parameters. Thus, multiple sets of parameters for the battery under test need to be compared with multiple sets of parameters for the reference battery to avoid inaccurate test results due to errors in one set of parameters, thereby improving test accuracy.

[0174] In another feasible embodiment, the reference parameter is the charging time, and the parameter to be measured is the corresponding voltage value. In this case, the reference value is the voltage value reached when the charging time of the reference battery is the reference parameter. The meaning of this embodiment is to compare the voltage values ​​reached by the tested battery and the reference battery under the same charging parameters and the same charging time. Here, the interval to be estimated can be (T d1 , T d2 ), and T d1 Less than T d2 .

[0175] Here, the specific implementation of step S203 may be as follows:

[0176] Step 1: Compare a voltage value corresponding to a first preset charging time of a tested battery with a first reference value to obtain a first comparison result.

[0177] Step 2: Compare the voltage value corresponding to the battery under test when the charging time is a second preset value with the first reference value to obtain a second comparison result.

[0178] Step 3: Determine whether the tested battery is normal based on the first comparison result and the second comparison result.

[0179] The first preset value and the second preset value can be any value within the interval to be estimated. For example, the first preset value can be T d1 At this time, the corresponding voltage value is the charging time T d1 The voltage value U reached by the battery under test d1 Here, the first reference value can be designed based on experience and actual working conditions. Preferably, the reference value can be the reference value of the battery when the charging time is T d1 The second preset value can be T d2 At this time, the corresponding voltage value is the charging time T d2 The voltage value U reached by the battery under test d2 .

[0180] Table 4

[0181]

[0182] For example, Table 4 shows the charging data for battery C, battery D, and two tested batteries. Taking battery C as the reference battery with an estimated interval of (48s, 3000s), the first preset value can be 48s, and the second preset value can be 3000s. One reference value is when the charging time reaches 48s, and the corresponding first reference value is 2.004V, which corresponds to the voltage of battery C when the charging time reaches 48s. The other reference value is when the charging time reaches 3000s, and the corresponding second reference value is 3.164V, which corresponds to the voltage of battery C when the charging time reaches 3000s.

[0183] The voltage value of the battery under test 3 when the charging time reaches 48 seconds is 1.948V. Comparing this with the first reference value of 2.004V, the first comparison result is that the voltage value of the battery under test 3 when the charging time reaches 48 seconds is less than the first reference value. Comparing this with the second reference value of 3.164V, the second comparison result is that the voltage value of the battery under test 3 when the charging time reaches 48 seconds is less than the second reference value. Both the first and second comparison results indicate that the voltage value corresponding to the charging time of the battery under test 3 when the charging time reaches the preset value is less than the baseline reference value, indicating that the battery under test 3 is abnormal.

[0184] Similarly, the voltage value reached by the tested battery 4 when the charging time reaches 48s is less than the corresponding first reference value, and the voltage value reached by the tested battery 4 when the charging time reaches 3000s is also less than the corresponding second reference value. Therefore, the tested battery 4 is also different from the reference battery, and the tested battery 4 can be judged to be abnormal.

[0185] This design allows for multiple reference parameters to be taken, and thus multiple sets of test parameters for the battery under test. By comparing these multiple sets of test parameters with multiple sets of baseline reference values, the battery under test can be inspected. This increased number of reference parameter sets improves test accuracy.

[0186] According to some embodiments of the present application, the difference between the voltage value corresponding to the charging time of the tested battery when the charging time is the first preset value and the voltage value corresponding to the charging time of the tested battery when the charging time is the second preset value is greater than 0.5V.

[0187] For example, the first preset value is T d1 , the voltage value corresponding to the charging time of the tested battery when it is the first preset value is U d1 , the second preset value is T d2 , the voltage value corresponding to the charging time of the tested battery when it is the second preset value is U d2 . Among them, ΔU d =U d2 -U d1 , ΔU d >0.5V.

[0188] In this way, the difference between the two groups of measured parameters of the measured battery is relatively large, which makes it easy to calculate and obtain accurate comparison results, thereby helping to improve the accuracy of detection.

[0189] Figure 12 for Figure 11 Schematic diagram of a modified example of the method shown. It is worth noting that, referring to Figure 12 As shown, before step S203, the detection method of this embodiment may further include the following steps:

[0190] Step S204: Acquire charging data of the reference battery.

[0191] Step S205 : determining, based on the charging data of the reference battery, a parameter value of the reference battery's parameter to be measured when the reference parameter is within the interval to be estimated.

[0192] Step S206 , determining a reference value according to the parameter value of the reference battery to be measured when the reference parameter is in the interval to be estimated.

[0193] The method for obtaining the charging data of the reference battery in step S204 can be specifically referred to in step S201, and will not be repeated in this embodiment. In step S204, multiple sets of charging data of the reference battery can be obtained. The purpose of step S206 is to design a baseline reference value, which is the parameter value of the parameter to be measured when the reference parameter of the reference battery is within the range to be estimated. For example, in Table 4, using battery C as the reference battery and the reference parameter as a charging time of 48 seconds, the baseline reference value is the voltage value of 2.004V reached by the reference battery after charging for 48 seconds.

[0194] Compared with designing a fixed reference value based on past experience, the detection method of this embodiment designs the reference value based on the actual charging data of the reference battery during the formation process. In this way, the reference value is less prone to error and is reasonably designed.

[0195] exist Figure 12 Based on the embodiment shown, step S206 can be implemented in the following manner:

[0196] The benchmark reference value is determined according to the average value of the parameter to be measured of the plurality of benchmark batteries when the reference parameter is in the interval to be estimated.

[0197] That is to say, when the reference parameter is a voltage value, the parameter to be measured is the average value of the charging time corresponding to the voltage value of multiple reference batteries; when the reference parameter is a charging time, the parameter to be measured is the average value of the voltage value corresponding to the charging time of multiple reference batteries.

[0198] Specifically, using battery C and battery D shown in Table 4 as reference batteries, if the reference parameter is that the battery charging time reaches 48 seconds, the parameter to be measured is the average of the voltage value reached by battery C when the charging time is 48 seconds and the voltage value reached by battery D when the charging time is 48 seconds, that is, the parameter to be measured = 2.004V + 2.007V = 2.0055V.

[0199] This embodiment takes the average value of the parameter values ​​of the parameters to be measured of multiple reference batteries as the reference value, which is beneficial to reducing the impact of the error of a single value on the test, thereby improving the accuracy of the test.

[0200] The above step S203 can also be implemented by the following steps:

[0201] Step 1: establishing a first relationship curve of the battery under test based on charging data of the battery under test;

[0202] Step 2: Establish a second relationship curve of the reference battery based on the charging data of the reference battery.

[0203] Step 3: Determine whether the battery under test is normal based on the comparison results of the estimated segment of the first relationship curve and the estimated segment of the second relationship curve; wherein the estimated segment of the first relationship curve is the curve segment of the first relationship curve in which the reference parameter is within the estimated interval, and the estimated segment of the second relationship curve is the curve segment of the second relationship curve in which the reference parameter is within the estimated interval.

[0204] In step 1, the charging data of the battery under test includes the voltage value of the battery under test and the corresponding charging time. The first relationship curve may include the voltage value and the charging time, with the voltage value being the vertical axis of the first relationship curve and the charging time being the horizontal axis of the first relationship curve. Step 1 can use Matlab to fit the multiple sets of charging data obtained in step S201 to form the first relationship curve.

[0205] In step 2, the horizontal axis of the second relationship curve graph is the charging time of the reference battery, and the vertical axis is the voltage value of the reference battery. The second relationship curve graph is formed by fitting the multiple sets of charging data obtained in step S204 using Matlab.

[0206] The estimated segment of the first relationship curve in step 3 is the curve segment where the reference parameter is in the estimated interval. For example, the first relationship curve of the battery under test can be as follows: Figure 13 As shown in the figure, taking the reference parameter as charging time and the interval to be estimated as (48s, 3000s) as an example, the segment to be estimated of the first relationship curve is the cs segment. Similarly, the segment to be estimated of the second relationship curve in step 3 is the curve segment of the reference parameter in the relationship curve of the reference battery in the interval to be estimated. Figure 13 This is a schematic diagram of a first relationship curve of batteries according to some embodiments of the present application.

[0207] The purpose of step 3 can be understood as comparing the segment to be estimated of the battery under test with the segment to be estimated of the reference battery. If the segment to be estimated of the battery under test coincides with or has a high degree of similarity to that of the reference battery, the battery under test can be determined to be normal. If the segment to be estimated of the battery under test does not coincide with or has a low degree of similarity to that of the reference battery, the battery under test can be determined to be abnormal.

[0208] With such an arrangement, by comparing the relationship curve obtained by fitting the charging data of the tested battery with the relationship curve obtained by fitting the charging data of the reference battery, it is determined whether the tested battery has an abnormality.

[0209] In summary, the detection circuit 130 can be configured to detect the voltage value, power value and charging time of the battery, and the battery charging data can include the voltage value, power value and charging time. Figure 1 and Figure 6 The detection method shown in the figure can judge whether the tested battery is qualified according to the voltage and power value of the tested battery. Figure 11 and Figure 12 The test method shown here determines whether the tested battery is qualified based on the detected voltage and charging time. In general, by obtaining charging data of the battery during the formation process, charging data includes voltage, charge level, and charging time. Based on this charging data, a variety of test methods can be selected to test the tested battery.

[0210] Based on the above embodiment, the charging data may further include the power value Q when charged to the corresponding voltage value. That is, the charging data of the tested battery acquired in step S201 in this embodiment is (T, U, Q).

[0211] In this example, after executing step S201, the method may further include the following steps:

[0212] Step S207 , determining the resistance value of the battery under test according to the charging data of the battery under test.

[0213] Step S208 , judging whether the battery under test is normal based on the comparison result of the resistance value of the battery under test and the reference resistance value.

[0214] Since the charging data (T, U, Q) of the battery under test is known, the current value corresponding to the battery under test being charged for a certain period of time can be calculated using the formula I=Q / T, and the resistance value of the battery under test can be calculated using the formula R=U / I. In this example, referring to step S201, the charging data (T, U, Q) of the reference battery can also be obtained, and based on this, the resistance value of the reference battery can also be calculated, and the resistance value of the reference battery can be the reference resistance value. Compare the resistance value of the battery under test with the reference resistance value. When the resistance value of the battery under test is equal to the reference resistance value, it can be determined that the battery under test is normal. When the resistance value of the battery under test is not equal to the reference resistance value, it can be determined that the battery under test is abnormal.

[0215] With this configuration, the detection method of this embodiment can also detect the resistance value of the battery under test. By comparing the resistance value of the battery under test with the reference resistance value, it can be determined whether the internal resistance of the battery under test is normal. In other words, the detection method of this embodiment is suitable for detecting the internal resistance performance of a battery.

[0216] Figure 14 The present application also provides a flowchart of a battery detection method according to some embodiments. Figure 14 In a specific embodiment, the battery detection method may include steps S301 to S3.

[0217] Step S301 , obtaining charging data of the battery under test during the formation process; the charging data includes a reference parameter and a parameter to be measured; wherein the reference parameter is a voltage value U, and the parameter to be measured is a charging time T.

[0218] Step S302 : performing fitting based on the charging data of the battery under test to establish a first relationship curve.

[0219] Step S303: According to the first relationship curve, the interval to be estimated of the reference parameter is determined as (T d1 , T d2 ), and determine the parameters to be measured as T d1The corresponding U d1 and T d2 The corresponding U d2 ; Among them, the reference parameter in the estimated interval is positively correlated with the measured parameter, and U d1 and U d2 The difference between them is less than 0.5V.

[0220] Step S304 , obtaining charging data of the reference battery during the formation process; the charging data includes a voltage value U and a charging time T.

[0221] Step S305 , performing fitting based on the charging data of the reference battery to establish a second relationship curve.

[0222] Step S306: According to the interval to be estimated (T d1 , T d2 ) and the second relationship curve, the benchmark battery charging time is determined to be T d1 The corresponding U J1 The charging time of the benchmark battery is T d2 The corresponding U J2 .

[0223] Step S307, according to U d1 with U J1 , and U d2 with U J2 The comparison results can be used to determine whether the tested battery is normal.

[0224] Figure 15 A schematic diagram of the structure of a battery detection device 300 according to some embodiments of the present application. Figure 15 The present invention provides a battery testing device 300, which includes a data acquisition module 310, a determination module 320, and a judgment module 330. The data acquisition module 310 is used to obtain charging data of the battery under test during the formation process; the charging data includes a voltage value and a corresponding power value; the determination module 320 is used to determine a test voltage range and a measured value of the battery under test based on the charging data of the battery under test; and the judgment module 330 is used to determine whether the battery under test is normal based on the measured value and a standard value.

[0225] In some embodiments, the measured value is a test power difference, which is the difference in power values ​​when the tested battery is charged from the first endpoint voltage value of the test voltage interval to the second endpoint voltage value of the test voltage interval, and the standard value is the standard deviation of the power values ​​when the reference battery is charged from the first endpoint voltage value of the test voltage interval to the second endpoint voltage value of the test voltage interval.

[0226] In some embodiments, the measured value is the total charging current of the measured battery, and the standard value is the total charging current of the reference battery.

[0227] In some embodiments, the judgment module 330 is further configured to calculate the self-discharge current of the battery under test based on the measured value and the standard value; compare the self-discharge current of the battery under test with the self-discharge current threshold to obtain a comparison result, and judge whether the battery under test is normal based on the comparison result.

[0228] In some embodiments, the data acquisition module 310 is further configured to obtain the self-discharge current of multiple batteries under test before comparing the self-discharge current of the battery under test with the self-discharge current threshold to obtain a comparison result, and determining whether the battery under test is normal based on the comparison result; the determination module 320 is further configured to determine the self-discharge current threshold based on the distribution of the self-discharge currents of the multiple batteries under test.

[0229] In some embodiments, the battery detection device 300 also includes a correction module, which is used to compare the self-discharge current of the tested battery with the self-discharge current threshold to obtain a comparison result, and after determining whether the tested battery is normal based on the comparison result, correct the self-discharge current threshold according to the self-discharge current of the reference battery.

[0230] In some embodiments, the data acquisition module 310 is further configured to obtain the charging data of the reference battery during the formation process before determining whether the tested battery is normal based on the measured value and the standard value; the determination module 320 is further configured to calculate the standard value based on the test voltage range and the charging data of the reference battery.

[0231] In some embodiments, the determination module 320 is further configured to perform fitting based on the charging data of the battery under test to generate a formation curve of the battery under test; wherein the formation curve includes the voltage value and the corresponding power value of the battery under test; and determine the test voltage range based on the slope of each point on the formation curve of the battery under test.

[0232] Continue to refer to Figure 15 The embodiment of the present application further provides a battery detection device 300, which includes: a data acquisition module 310, a determination module 320, and a judgment module 330. The data acquisition module 310 is used to obtain charging data of the battery under test during the formation process; the charging data includes a reference parameter and a parameter to be measured, wherein one of the reference parameter and the parameter to be measured is a voltage value and the other is the charging time required to charge to the corresponding voltage value; the determination module 320 is used to determine the parameter value of the parameter to be measured of the battery under test when the reference parameter is in the interval to be estimated based on the charging data of the battery under test; the judgment module 330 is used to determine whether the battery under test is normal based on the comparison result of the parameter value of the parameter to be measured of the battery under test when the reference parameter is in the interval to be estimated with the benchmark reference value.

[0233] In some embodiments, the reference parameter is the charging time, and the parameter to be measured is the voltage value. The judgment module 330 is further configured to compare the voltage value corresponding to the battery under test when the charging time is a first preset value with the first reference value to obtain a first comparison result; compare the voltage value corresponding to the battery under test when the charging time is a second preset value with the second reference value to obtain a second comparison result; and judge whether the battery under test is normal based on the first comparison result and the second comparison result.

[0234] In some embodiments, a difference between a voltage value corresponding to a first preset charging time of the battery under test and a voltage value corresponding to a second preset charging time of the battery under test is greater than 0.5V.

[0235] In some embodiments, the data acquisition module 310 is further configured to acquire the charging data of the reference battery before judging whether the battery under test is normal based on the comparison result of the parameter value of the measured parameter of the battery under test when the reference parameter is in the interval to be estimated and the benchmark reference value; the determination module 320 is further configured to determine the parameter value of the measured parameter of the reference battery when the reference parameter is in the interval to be estimated based on the charging data of the reference battery; the judgment module 330 is further configured to determine the benchmark reference value based on the parameter value of the measured parameter of the reference battery when the reference parameter is in the interval to be estimated.

[0236] In some embodiments, the determination module 320 is further configured to determine the benchmark reference value according to an average value of parameter values ​​of the measured parameters of a plurality of reference batteries when the reference parameter is in the interval to be estimated.

[0237] In some embodiments, the judgment module 330 is further configured to establish a first relationship curve of the battery under test based on the charging data of the battery under test; establish a second relationship curve of the reference battery based on the charging data of the reference battery; and judge whether the battery under test is normal based on the comparison result of the to-be-estimated segment of the first relationship curve and the to-be-estimated segment of the second relationship curve; wherein, the to-be-estimated segment of the first relationship curve is the curve segment in which the reference parameter in the first relationship curve is in the to-be-estimated interval, and the to-be-estimated segment of the second relationship curve is the curve segment in which the reference parameter in the second relationship curve is in the to-be-estimated interval.

[0238] In some embodiments, the charging data also includes the power value when charged to the corresponding voltage value; the determination module 320 is further configured to determine the resistance value of the battery under test based on the charging data of the battery under test after the data acquisition module 310 obtains the charging data of the battery under test during the formation process; the judgment module 330 is further configured to judge whether the battery under test is normal based on the comparison result of the resistance value of the battery under test and the reference resistance value.

[0239] Figure 16 Schematic diagram of the structure of electronic devices in some embodiments of the present application. Figure 16, an embodiment of the present application also provides an electronic device, including: a memory 401 and at least one processor 402. The memory 401 is used to store program instructions. The processor 402 is used to implement the battery detection method in this embodiment when the program instructions are executed. The specific implementation principle can be found in the above embodiment, and this embodiment will not be repeated here. The electronic device may also include an input / output interface 403. The input / output interface 403 may include an independent output interface and an input interface, or it may be an integrated interface that integrates input and output. Among them, the output interface is used to output data, and the input interface is used to obtain input data.

[0240] One embodiment of the present application provides a computer-readable storage medium having executable instructions stored therein. When at least one processor 402 of an electronic device executes the executable instructions, the battery detection method described in the above embodiment is implemented. The computer-readable storage medium may be a ROM, random access memory 401 (RAM), a CD-ROM, a magnetic tape, a floppy disk, or an optical data storage device.

[0241] The present application provides a computer program product, including a computer program, which is executed by the processor 402 to implement the present application. Figure 1 and Figure 14 The battery detection method provided in any one of the corresponding embodiments.

[0242] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery detection method, characterized in that: include: Obtain charging data of the battery under test during the formation process; The charging data includes a reference parameter and a parameter to be measured, wherein the parameter to be measured is a voltage value, and the reference parameter is the charging time required to charge to the corresponding voltage value; determining, according to the charging data of the battery under test, a parameter value of the parameter to be measured of the battery under test when the reference parameter is in the interval to be estimated; Determining whether the battery under test is normal according to a comparison result between a parameter value of the measured parameter of the battery under test when the reference parameter is in the estimated interval and a benchmark reference value specifically includes: Comparing the voltage value of the tested battery corresponding to the first preset charging time with a reference value to obtain a first comparison result; Comparing the voltage value of the tested battery corresponding to the second preset charging time with a reference value to obtain a second comparison result; Whether the tested battery is normal is determined according to the first comparison result and the second comparison result.

2. The detection method according to claim 1, characterized in that A difference between the voltage value corresponding to the battery under test when the charging time is a first preset value and the voltage value corresponding to the battery under test when the charging time is a second preset value is greater than 0.5V.

3. The detection method according to claim 1, wherein Before judging whether the battery under test is normal based on a result of comparing a parameter value of the measured parameter of the battery under test when the reference parameter is in the estimated interval with a benchmark reference value, the method further includes: Get the charging data of the reference battery; determining, based on the charging data of the reference battery, a parameter value of the parameter to be measured of the reference battery when the reference parameter is in the interval to be estimated; The reference value is determined according to the parameter value of the parameter to be measured of the reference battery when the reference parameter is in the interval to be estimated.

4. The detection method according to claim 3, characterized in that The determining the reference value according to the parameter value of the measured parameter of the reference battery when the reference parameter is in the estimated interval includes: The reference value is determined according to an average value of the measured parameters of a plurality of reference batteries when the reference parameter is in the estimated interval.

5. The detection method according to any one of claims 1 to 4, characterized in that The determining whether the battery under test is normal according to a comparison result between a parameter value of the measured parameter of the battery under test when the reference parameter is in the estimated interval and a benchmark reference value includes: Establishing a first relationship curve of the battery under test according to the charging data of the battery under test; establishing a second relationship curve of the reference battery according to charging data of the reference battery; Whether the battery under test is normal is determined based on a comparison result of the to-be-estimated segment of the first relationship curve and the to-be-estimated segment of the second relationship curve; wherein the to-be-estimated segment of the first relationship curve is a curve segment in which the reference parameter in the first relationship curve is within the to-be-estimated interval, and the to-be-estimated segment of the second relationship curve is a curve segment in which the reference parameter in the second relationship curve is within the to-be-estimated interval.

6. The detection method according to any one of claims 1 to 4, characterized in that The charging data also includes the power value when charged to the corresponding voltage value; After obtaining the charging data of the battery under test during the formation process, the battery detection method further includes: determining a resistance value of the battery under test according to charging data of the battery under test; Whether the battery under test is normal is determined based on a comparison result between the resistance value of the battery under test and a reference resistance value.

7. A battery detection device comprising: A data acquisition module is used to obtain charging data of the battery under test during the formation process; The charging data includes a reference parameter and a parameter to be measured, wherein the parameter to be measured is a voltage value, and the reference parameter is the charging time required to charge to the corresponding voltage value; a determination module, configured to determine, based on the charging data of the battery under test, a parameter value of the parameter to be measured of the battery under test when the reference parameter is within the interval to be estimated; A judgment module is configured to judge whether the battery under test is normal based on a comparison result between a parameter value of the measured parameter of the battery under test when the reference parameter is in the estimated interval and a benchmark reference value, specifically comprising: Comparing the voltage value of the tested battery corresponding to the first preset charging time with a reference value to obtain a first comparison result; Comparing the voltage value of the tested battery corresponding to the second preset charging time with a reference value to obtain a second comparison result; Whether the tested battery is normal is determined according to the first comparison result and the second comparison result.

8. An electronic device, wherein: The electronic device includes a memory and a processor, The memory stores a computer program; The processor executes the computer program stored in the memory, so that the electronic device performs the detection method according to any one of claims 1 to 6.

9. A computer-readable storage medium, wherein: The computer-readable storage medium stores a computer program, which is used to implement the detection method according to any one of claims 1 to 6 when executed by a processor.

10. A computer program product, wherein The computer program product comprises a computer program, and when the computer program is executed by a processor, the computer program is used to implement the detection method according to any one of claims 1 to 6.

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