WO2024031261A1 - Procédé de test de batterie, appareil, dispositif, support de stockage et produit programme - Google Patents

Procédé de test de batterie, appareil, dispositif, support de stockage et produit programme Download PDF

Info

Publication number
WO2024031261A1
WO2024031261A1 PCT/CN2022/110933 CN2022110933W WO2024031261A1 WO 2024031261 A1 WO2024031261 A1 WO 2024031261A1 CN 2022110933 W CN2022110933 W CN 2022110933W WO 2024031261 A1 WO2024031261 A1 WO 2024031261A1
Authority
WO
WIPO (PCT)
Prior art keywords
battery
under test
value
self
test
Prior art date
Application number
PCT/CN2022/110933
Other languages
English (en)
Chinese (zh)
Inventor
左启琪
李伟
Original Assignee
宁德时代新能源科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Priority to PCT/CN2022/110933 priority Critical patent/WO2024031261A1/fr
Publication of WO2024031261A1 publication Critical patent/WO2024031261A1/fr

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]

Definitions

  • 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.
  • Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection.
  • battery technology is an important factor related to their development.
  • the manufactured batteries must be tested before leaving the factory to screen out unqualified batteries.
  • the manufactured battery is usually left aside for a period of time, and then the battery's power or K value and other parameters are monitored to test whether the battery is normal.
  • the battery's power or K value and other parameters are monitored to test whether the battery is normal.
  • This application aims to solve at least one of the technical problems existing in the prior art.
  • one purpose of this application is to propose a battery detection method, device, equipment, storage medium and program product to solve the problem that it takes a long time to test whether the battery is qualified and the test cycle is long.
  • An embodiment of the first aspect of the present application provides a battery detection method, which includes: obtaining charging data of the battery under test in the formation process; wherein the charging data includes a voltage value and a corresponding power value; according to the charging data of the battery under test, Determine the test voltage range and measured value of the battery under test; judge whether the battery under test is normal based on the measured value and standard value.
  • this 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 resting process and testing process of battery manufacturing, so as to screen out unqualified batteries in advance. In this way, no need Putting the battery aside for a period of time will help shorten the test time and test cycle of the battery, improve the test efficiency, and in turn help relieve the pressure on the battery manufacturer's storage space and cash flow.
  • each battery can be tested for performance using its charging data in the formation process, thereby achieving full battery performance.
  • the effect of inspection is that each battery can be tested for performance, which is helpful to avoid unqualified batteries from leaving the factory.
  • the measured value is the test power difference
  • the test power difference is the difference in power value when the battery under test is charged from the first endpoint voltage value of the test voltage interval to the second endpoint voltage value of the test voltage interval
  • the standard value is the standard deviation value of the power value of the reference battery when it is charged from the first endpoint voltage value of the test voltage interval to the second endpoint voltage value of the test voltage interval.
  • the measured value is the total charging current of the battery under test
  • the standard value is the total charging current of the reference battery.
  • judging whether the battery under test is normal based on the measured value and the standard value includes: calculating the self-discharge current of the battery under test based on the measured value and the standard value; summing the self-discharge current of the battery under test and The comparison result is obtained by comparing the self-discharge current threshold, and based on the comparison result, it is judged whether the battery under test is normal.
  • the method before comparing the self-discharge current of the tested battery with the self-discharge current threshold to obtain a comparison result, and before determining whether the tested battery is normal based on the comparison result, the method further includes: obtaining the self-discharge currents of multiple tested batteries;
  • the self-discharge current threshold is determined based on the distribution of self-discharge currents of multiple tested batteries.
  • the self-discharge current threshold is determined based on the distribution of the self-discharge current of the battery under test.
  • the value of the self-discharge current used to evaluate battery performance is a range, not a single value, which is beneficial to improving the accuracy and rationality of battery screening. .
  • the method further includes: based on the self-discharge current of the reference battery, evaluating the self-discharge The current threshold is corrected.
  • 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, in order to improve the accuracy of the self-discharge current threshold.
  • the battery under test before determining whether the battery under test is normal based on the measured value and the standard value, it also includes: obtaining the charging data of the reference battery in the formation process; calculating the standard value based on the test voltage interval and the charging data of the reference battery. .
  • the standard value is calculated based on the actual charging data of the reference battery in the formation process. In this way, the standard value is not prone to errors and the design is reasonable.
  • determining the test voltage range of the battery under test according to the charging data of the battery under test includes: fitting according to the charging data of the battery under test to generate a formation curve of the battery under test; wherein the formation curve includes the formation curve of the battery under test. The voltage value of the battery under test and the corresponding power value; determine the test voltage range based on the slope of each point on the formation curve of the battery under test. A formation curve is established based on the charging data of the battery under test, and the test voltage range is determined based on the changes in the slope of each point on the formation curve. This fully takes into account the changing characteristics of the formation curve, which is beneficial to improving test accuracy.
  • a second embodiment of the present application provides a battery detection device.
  • the battery detection device includes: a data acquisition module, a determination module and a judgment module.
  • the data acquisition module is used to obtain the charging data of the battery under test in the formation process;
  • the charging data includes the voltage value and the corresponding power value;
  • the determination module is used to determine the test voltage of the battery under test based on the charging data of the battery under test. interval and measured value;
  • the judgment module is used to judge whether the battery under test is normal based on the measured value and the standard value.
  • the measured value is the test power difference
  • the test power difference is the difference in power value when the battery under test is charged from the first endpoint voltage value of the test voltage interval to the second endpoint voltage value of the test voltage interval
  • the standard value is the standard deviation value of the power value of the reference battery when it is charged from the first endpoint voltage value of the test voltage interval to the second endpoint voltage value of the test voltage interval.
  • the measured value is the total charging current of the battery under test
  • the standard value is the total charging current of the reference battery
  • the judgment module 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. The result determines whether the battery under test is normal.
  • the data acquisition module is further configured to obtain the comparison results of the self-discharge current of the battery under test and the self-discharge current threshold, and determine whether the battery under test is normal based on the comparison result.
  • Self-discharge current the determining module is further configured to determine the self-discharge current threshold according to the distribution of self-discharge currents of the plurality of tested batteries.
  • the battery detection device also includes a correction module.
  • the correction module is used to compare the self-discharge current of the tested battery with the self-discharge current threshold to obtain a comparison result, and then determine whether the tested battery is normal based on the comparison result.
  • the self-discharge current threshold is corrected based on the self-discharge current of the reference battery.
  • the data acquisition module is further configured to obtain the charging data of the reference battery in the formation process before determining whether the battery under test is normal based on the measured value and the standard value; the determination module is further configured to obtain charging data based on the test voltage interval. And the charging data of the reference battery to calculate the standard value.
  • the determination module is further configured to perform fitting according to the charging data of the battery under test and 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; according to the Measure the slope of each point on the battery's formation curve to determine the test voltage range.
  • the embodiment of the third aspect of the present application provides an electronic device, including 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 executes the battery detection method described in the first aspect. .
  • the 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 executed by the processor, the computer program is used to implement the detection of the battery as described in the first aspect. method.
  • the embodiment of the fifth aspect of the present application provides a computer program product, wherein the computer program product is a computer program.
  • the computer program When the computer program is executed by a processor, it is used to implement the battery detection method described in the first aspect.
  • Figure 1 is a schematic flow chart of a battery detection method according to some embodiments of the present application.
  • Figure 2 is a schematic diagram of battery formation according to an embodiment of the present application.
  • Figure 3 is a schematic circuit diagram of the battery during charging according to some embodiments of the present application.
  • Figure 4a is a schematic diagram of the charging principle of a normal battery
  • Figure 4b is a schematic diagram of the charging principle of an abnormal battery with internal short circuit
  • Figure 5 is a schematic diagram of the voltage-electricity relationship curve of a normal battery and an abnormal battery
  • Figure 6 is a schematic flowchart of a modified example of the method shown in Figure 1;
  • Figure 7 is a scatter diagram of the self-discharge current of the battery under test in the battery detection method according to some embodiments of the present application.
  • Figure 8 shows the normal distribution diagram of the self-discharge current of the reference battery.
  • Figure 9 is a schematic diagram of the formation curve of the tested battery according to some embodiments of the present application.
  • Figure 10 is a schematic diagram of the voltage charging time relationship curve of a normal battery and an abnormal battery
  • Figure 11 is a schematic flow chart of a battery detection method according to other embodiments of the present application.
  • Figure 12 is a schematic flowchart of a modified example of the method shown in Figure 11;
  • Figure 13 is a schematic diagram of a first relationship curve of a battery according to some embodiments of the present application.
  • Figure 14 is a schematic flowchart of a battery detection method according to some embodiments of the present application.
  • Figure 15 is a schematic structural diagram of a battery detection device according to some embodiments of the present application.
  • Figure 16 is a schematic structural diagram of an electronic device according to some embodiments of the present application.
  • an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application.
  • the appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.
  • multiple refers to more than two (including two).
  • multiple groups refers to two or more groups (including two groups), and “multiple pieces” refers to It is more than two pieces (including two pieces).
  • Power batteries are widely used in fields such as mobile devices and electric vehicles. Power batteries need to be tested before leaving the factory to screen out batteries that fail in self-discharge, thereby ensuring that all batteries leaving the factory have excellent performance.
  • the cell of the battery includes a positive electrode piece 210, a negative electrode piece 220, a separator 230 and an electrolyte 240.
  • impurities are mixed into the interior of the cell, and some of the impurities can conduct electricity.
  • the positive electrode piece 210 and the negative electrode piece 220 will cause 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, if 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 the self-discharge phenomenon of the battery. Based on this, although there are many methods used to characterize the self-discharge performance of batteries in related technologies, the general idea is to leave the manufactured battery aside for a period of time and monitor the parameter changes during the battery placement process.
  • the researchers of this application thought that there are also differences in the parameters of normal batteries 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.
  • 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 Each battery must go through a processing process, so this can make full use of the data during formation, saving storage time, which in turn helps shorten the test time.
  • the battery detection method and device disclosed in the embodiments of the present application can be applied to the battery manufacturing process, and specifically can be applied to the later processes 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.
  • the battery can be used as a power source for the electrical device to provide power to the electrical device.
  • the electrical devices can be but are not limited to mobile phones, tablets, laptops, electric toys, power tools, battery cars, electric vehicles, ships, spacecraft, etc.
  • Electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, electric airplane toys, etc.
  • Spacecraft can include airplanes, rockets, space shuttles, spaceships, etc.
  • the execution subject of the battery detection method provided by the embodiment of the present application may be a battery detection device, or may be an electronic device capable of controlling the battery detection device, such as a server or terminal equipment.
  • the following embodiments take a battery detection device as an example for schematic description.
  • the embodiment of the present application provides a battery detection method.
  • the method is used to test whether the battery is normal. According to the detection results of the method, batteries with unqualified performance can be screened out.
  • the battery detection method obtains the charging data of the battery under test during the formation process, and determines whether the battery under test is normal based on the charging data of the battery under test.
  • the battery under test refers to the battery that is newly manufactured and to be tested.
  • the model and type of the battery under test are not limited.
  • the battery detection method in this embodiment uses the charging data of the battery under test during the formation process, the detection method can be implemented after the formation process of the battery manufacturing process.
  • FIG 1 is a schematic flowchart of a battery detection method according to some embodiments of the present application.
  • the method includes the following steps S101 to S103.
  • Step S101 Obtain the charging data of the battery under test in the formation process; the charging data includes voltage values and corresponding power values.
  • Step S102 Determine the test voltage range and measured value of the battery under test based on the charging data of the battery under test.
  • Step S103 Determine whether the battery under test is normal based on the measured value and the standard value.
  • the formation process is also called activation. It is the process of charging a newly produced and packaged battery for the first time to activate the active materials inside the battery.
  • the battery can be used normally only after the active materials inside the battery are activated. Therefore, the formation process is an indispensable link in the production and manufacturing process of each battery.
  • FIG. 2 is a schematic diagram of the formation of a battery 200 according to some embodiments of the present application.
  • the specific implementation method of the formation process may be: using the power supply 110 to charge the battery 200 so that the power of the battery 200 reaches a preset power.
  • the battery 200 is equivalent to a capacitor. Both ends of the capacitor are connected to the positive and negative poles of the power supply 110 respectively.
  • a charging circuit 120 is connected between the power supply 110 and the capacitor. The charging circuit 120 can regulate and control the power supply. 110 supplies the voltage to the capacitor. 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 capacitor's power to continuously increase.
  • FIG. 3 is a schematic circuit diagram of the battery 200 during charging according to some embodiments of the present application. It should be noted that during the formation process, the power supply 110 can specifically provide a constant current to charge the battery 200 with a constant current.
  • a detection circuit 130 may also be connected between the power supply 110 and the battery 200 .
  • step S101 can obtain charging data by obtaining the data detected by the detection circuit 130 .
  • 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.
  • the detection circuit 130 at this time may include a voltmeter. 131 and the power detector 132.
  • the voltmeter 131 is connected in parallel with the capacitor to detect the voltage value of the capacitor.
  • the power detector 132 uses the Coulomb detection method to detect the power value of the battery 200, in which the resistor R1 is the internal resistance of the power detector 132.
  • the voltmeter 131 can also be replaced by other voltage sensors.
  • the detection circuit 130 can Multiple sets of charging data detected. In this way, multiple sets of charging data of the battery 200 under test can be obtained in step S101, and each set of charging data can be (U, Q).
  • the obtained charging data of the battery under test may include (2V, 6734.3mA ⁇ h), (3.2V, 20038.4mA ⁇ h), (4V, 35205.1mA ⁇ h). h) etc.
  • step S102 is to select the first endpoint voltage value U C1 and the second endpoint voltage value U C2 from the charging data of the battery under test as the endpoints of the test voltage interval, where, U C1 ⁇ UC2 , Then the test voltage interval is ( UC1 , U C2 ).
  • the test voltage range of a battery under test may be (1.8V, 3V), (2V, 3.2V) or (2.5V, 4V).
  • the measured value can also be determined based on the voltage value U of the battery 200 and the electric quantity value Q of the battery 200 .
  • the standard value in step S103 can be understood as the value corresponding to the measured value of 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.
  • the reference battery is formed
  • the charging parameters of the process (such as charging current or charging voltage) are still the same as the charging parameters of the battery under test in the formation process.
  • the purpose of step S103 is to compare the measured value of the battery under test with the measured value of the reference battery to determine whether the battery under test is normal.
  • the process flow of the battery 200 is the sealing process, the formation process, the resting process, the testing process, and the capacity dividing process. That is, the battery 200 is first put aside and then the discharge parameters of the battery 200 are detected to test the performance of the battery 200.
  • This embodiment uses the charging data of the battery 200 during the formation process to determine the performance of the battery 200 . Therefore, the detection method provided by this embodiment can be executed after the formation process and before the resting process. Designed in this way, the detection method can be used to test the performance of the battery 200 using the charging data of the formation process before the resting process and the testing process, so as to screen out unqualified batteries 200 in advance. In this way, there is no need to leave the battery 200 aside for a period of time. It is conducive to shortening the test time and test cycle of the battery 200 and improving the test efficiency, which is conducive to easing the pressure on the storage space and cash flow of the battery 200 manufacturer.
  • each battery 200 can be tested for performance using its charging data in the formation process, and thus can The effect of full battery inspection is achieved, that is, each battery 200 can be tested for performance, which is helpful to avoid unqualified batteries 200 from leaving the factory.
  • the measured value can be the test power difference ⁇ Q C ; where the test power difference ⁇ Q C is the charge of the battery under test from the first endpoint voltage value U C1 of the test voltage interval to the second endpoint voltage. The difference between the electric quantity value Q at the value U C2 .
  • Figure 4a is a schematic diagram of the charging principle of a normal battery
  • Figure 4b is a schematic diagram of the charging principle of an abnormal battery with an internal short circuit.
  • the battery 200 is normal, when the battery 200 is charging, the lithium ions Li + in the positive electrode of the battery move to the negative electrode of the battery through the separator 230.
  • the electrons e - in the positive electrode of the battery migrate to the negative electrode of the battery along the charging circuit 120. In this way, the electrons e - at the positive electrode of the battery decrease and the electrons e - at the negative electrode increase.
  • a potential difference is formed between the positive electrode and the negative electrode of the battery. As the electrons e - move, the voltage of the battery 200 increases.
  • the positive electrode and the negative electrode of the battery 200 will be slightly conductive and form a conductive loop 140.
  • the conductive loop 140 is connected in parallel with the charging circuit 120.
  • the electrons e - from the positive electrode of the battery migrate to the negative electrode of the battery along the charging circuit 120
  • part of the electrons e - from the negative electrode of the battery migrate to the positive electrode of the battery along the conduction loop 140 .
  • Some of the lithium ions Li + embedded in the negative electrode of the battery are deintercalated and move to the battery through the separator 230 positive electrode.
  • Figure 5 is a schematic diagram of the voltage-electricity relationship curve of a normal battery and an abnormal battery.
  • the charging data of the battery 200 is fitted to obtain a voltage-electricity relationship curve.
  • the voltage-electricity relationship curve is used to represent the relationship between the electric quantity value of the battery 200 and the voltage change. It should be noted that the voltage-electricity relationship curve of a normal battery can be shown as the solid line in Figure 5, and the voltage-electricity relationship curve of an abnormal battery can be shown as the dotted line in Figure 5.
  • the voltage value of the battery under test is designed to be quantitative, and the measured value and the standard value are designed to be related to the power value. By comparing the measured value and the standard value, it can be judged whether the battery under test is normal.
  • the measured value may specifically be the electric quantity value corresponding to when the battery under test is charged to the target voltage value in the test voltage range.
  • the standard value is the corresponding power value when the reference battery is charged to the target voltage value. If the measured value is different from the standard value, the battery under test can be considered abnormal. If the measured value is the same as the standard value, the battery under test can be considered normal.
  • the target voltage value may 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.
  • the charging data of the battery under test includes (2V, 6734.3mA ⁇ h), (3.2V, 20038.4mA ⁇ h), (4V, 35205.1mA ⁇ h), and the test voltage range is (2V, 3.2V)
  • the target If the voltage value can be the first endpoint voltage value, then the measured value can be determined to be 6734.3mA ⁇ h. If the target voltage value can be the second endpoint voltage value, then the measured value can be determined to be 20038.4mA ⁇ h.
  • the standard value can be designed based on the charging data in the formation process of the benchmark battery that has been tested and determined. Moreover, the average value of the electric quantity values corresponding to multiple reference batteries charged to the target voltage value can be taken as the standard value. In this way, the standard value is designed with reference to the charging data of multiple reference batteries to improve the accuracy of the test.
  • the measured value may be the test power difference ⁇ Q C
  • the test power difference ⁇ Q C is when the battery under test is charged from the first endpoint voltage value U C1 of the test voltage interval to the second endpoint voltage value U C2
  • the difference in electric quantity value Q at that time that is to say, the test electric quantity difference ⁇ Q C is equal to the electric quantity value Q C2 corresponding to the battery under test being charged to U C2 minus the electric quantity value Q C1 corresponding to charging to U C1 .
  • the standard value is the standard power difference ⁇ Q B
  • the standard power difference ⁇ Q B is the standard deviation value of the power value Q when the reference battery is charged from UC1 to UC2 .
  • the battery detection method in this embodiment is by comparing the power difference ⁇ Q C and the standard power difference ⁇ Q B when the tested battery is charged from the first endpoint voltage value U C1 to the second endpoint voltage value U C2 . to determine whether the battery under test is normal.
  • the charging data of the battery under test includes (2V, 6734.3mA ⁇ h), (3.2V, 20038.4mA ⁇ h), (4V, 35205.1mA ⁇ h)
  • the test voltage range is determined to be (2V, 3.2V )
  • the standard power difference ⁇ Q B 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 ⁇ Q B can be designed as 13304.1mA ⁇ h, 13600mA ⁇ h, 14000mA ⁇ h, etc., this embodiment does not limit this.
  • the detection method in this example uses the charging data of the battery under test in the formation process to calculate the test power difference of the battery under test. Based on the test power difference and the standard power difference, it can be identified whether the battery under test is different from the reference battery, and then it can be screened Unqualified batteries under test are produced.
  • the difference in power between the normal battery charged from U C1 to U C2 and the difference in power between the abnormal battery charged from U C1 to U C2 are relatively large.
  • the measured value is designed to be the test power difference, which is different from the direct design. The measured value is compared with the corresponding power value when the battery under test is charged to the target voltage value, which helps avoid misjudgments and improves the accuracy of battery testing.
  • the measured value may be the total charging current I of the battery under test .
  • the total charging current refers to the total current on the circuit between the battery and the power supply 110 during the charging process.
  • the conductive loop 140 is connected in parallel with the charging circuit 120, and the positive electrode plate 210 and the negative electrode plate are 220 and the electrolyte 240 have internal resistance, so the conduction loop 140 can be regarded as having a resistor R2 connected in series, and the electrons e at the positive electrode of the battery migrate from the positive electrode of the battery along the charging circuit 120 to the negative electrode of the battery to form a chemical current I chemistry , the part of the negative electrode of the battery. The electrons e - migrate 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.
  • the self-discharge current I self-discharge can be understood as the current input by the power supply 110 to compensate for the power consumed by the battery's self-discharge.
  • the total charging current I of a normal battery is always different from the total charging current I of an abnormal battery. Based on this difference, in this embodiment, by designing the measured value to be the total charging current I of the battery under test, and comparing the measured value with the standard value, it can also be determined whether the battery under test is normal. It should be understood that in this example, the standard value may be the total charging current I of the reference battery.
  • ⁇ TC refers to the charging time required for the battery under test to charge from the first endpoint voltage value U C1 to the second endpoint voltage value U C2 .
  • the measured value I After determining the measured value I, compare the measured value I with the standard value I. If the measured value I is consistent with the standard value I, the battery under test is judged to be normal. If the measured value I is inconsistent with the standard value I, the battery under test is judged to be abnormal.
  • the detection method in this embodiment is to use the charging data of the battery under test in the formation process to calculate the total charging current of the battery under test, and then based on the total charging current of the battery under test and the total charging current of the reference battery, the battery under test can be identified Whether it is different from the reference battery, and then the unqualified tested batteries can be screened out. Compared with using the power difference to detect whether the battery is qualified, the total charging current of the battery under test can better reflect the short circuit condition inside the battery under test, and the detection effect is better.
  • FIG. 6 is a schematic flowchart of a modified example of the method shown in FIG. 1 .
  • step S103 may include the following implementation steps:
  • S1032 Compare the self-discharge current of the battery under test and the self-discharge current threshold to obtain a comparison result, and determine whether the battery under test is normal based on the comparison result.
  • the total charging current I of a normal battery is always different from the total charging current I of an abnormal battery.
  • the chemical current I formed by converting electrical energy into chemical energy when charging the normal battery is equal to the chemical current I formed by converting electrical energy into chemical energy when charging the abnormal battery. Therefore, the difference between the total charging current Itotal of the normal battery and the total charging current Itoto of the abnormal battery is the self-discharge current Iself-discharge .
  • this embodiment can also determine whether the battery under test is normal by calculating the self-discharge current IC self-discharge of the battery under test and comparing the self-discharge current IC self-discharge of the battery under test with the self-discharge current threshold.
  • the standard value is the total charging current I of the reference battery.
  • the self-discharge current of the reference battery can be regarded as 0 mA.
  • the total charging current I of the reference battery is equal to the chemical current of the reference battery. Since the model and type of the reference battery and the battery under test are the same, the chemical current of the battery under test is equal to the chemical current of the reference battery.
  • the self-discharge current threshold in step S1032 can be understood as the self-discharge current I B self-discharge of the reference battery.
  • the comparison result is that the self-discharge current of the battery under test I C self-discharge is equal to the self-discharge current threshold I B self-discharge , the battery under test can be judged to be normal.
  • the comparison result is that the self-discharge current of the battery under test I C self-discharge is not equal to If the self-discharge current threshold I B self-discharges , it can be judged that the battery under test is abnormal.
  • 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.
  • the self-discharge current I C self-discharge of the battery under test is calculated to be equal to 0 mA, then the battery under test can be judged to be normal. If the self-discharge current I C self-discharge of the battery under test is calculated not to be 0 mA, then it can be determined that the battery under test is normal. Determine whether the battery under test is abnormal.
  • the self-discharge current threshold can also be determined in other ways.
  • the battery detection method of this embodiment may further include:
  • Step S104 Obtain the self-discharge currents of multiple batteries under test.
  • Step S105 Determine a self-discharge current threshold based on the distribution of self-discharge currents of multiple batteries under test.
  • step S104 can obtain the self-discharge current IC self- discharge of multiple batteries under test. It should be pointed out that due to the inevitable presence of some impurities in the battery manufacturing process, general normal batteries have slight self-discharge.
  • the self-discharge current I of the battery under test is not measured directly using a detection instrument, it is measured based on the difference between the total charging current I of the battery under test and the standard value I. Calculated, in which the standard value I is only used as a reference value.
  • the actual calculated total charging current I of the battery under test may be higher than the standard value I, or may be lower than or equal to the standard value I. Therefore, the calculated self-discharge current I C of the battery under test may be greater than 0 mA, or may be less than or equal to 0 mA.
  • step S105 the self-discharge current I C self-discharge and battery number of multiple batteries under test can be counted, and a distribution diagram of the self-discharge current of the battery under test can be drawn.
  • Figure 7 shows some diagrams of the present application. Scatter plot of the self-discharge current of the battery under test in the battery detection method of the embodiment.
  • the self-discharge current of the reference battery can be regarded as 0mA. Based on Figure 7, it can be seen that the self-discharge current IC of most tested batteries is scattered around 0mA, and the self- discharge current IC of a small number of tested batteries is much greater than 0mA. . In Figure 7, it can be determined that the point where the self-discharge current IC exceeds 1A is a discrete point, and the battery under test whose self -discharge current IC exceeds 1A is an abnormal battery.
  • the normal distribution curve of the self-discharge current can be drawn according to the value and frequency of self-discharge of the battery under test.
  • the battery under test can be determined to be a normal battery.
  • the self-discharge current I C self-discharge is basically distributed between [0-3 ⁇ , 0+3 ⁇ ], ⁇ refers to the standard deviation.
  • ⁇ refers to the standard deviation.
  • the self-discharge current I C of the battery under test is in the range of 0-3 ⁇ ⁇ I C self-discharge ⁇ 0 + 3 ⁇
  • the battery under test can be judged to be a normal battery .
  • the range of self-discharge is I C self-discharge ⁇ 0-3 ⁇ or I C self-discharge >0+3 ⁇
  • the battery under test can be judged to be an abnormal battery.
  • the self-discharge current threshold can be designed to be 0mA.
  • the specific implementation method of step S1032 is: compare the self-discharge current I C self-discharge of the battery under test with 0mA. The comparison result obtained at this time is I C self-discharge , and then whether the absolute value of I C self-discharge is Less than or equal to 3 ⁇ to determine whether the battery under test is normal.
  • the self-discharge current threshold may include a first critical value and a second critical value, where the first critical value is -3 ⁇ (unit: mA) and the second critical value is 3 ⁇ (unit: mA). ).
  • step S1032 can be implemented by using the following steps:
  • Step 3 When the first comparison result ⁇ d1 is greater than 0 and the second comparison result ⁇ d2 is less than 0, determine that the battery under test is a normal battery.
  • This embodiment determines the self-discharge current threshold based on the distribution of the self-discharge current of the battery under test. In this way, by comparing the self-discharge current of the battery under test and the self-discharge current threshold, it can be determined whether the self-discharge performance of the battery under test is normal. Based on the above, it can be seen that the value of self-discharge current used to evaluate battery performance can be a range instead of a single value, which will help improve the accuracy and rationality of battery screening.
  • the battery detection method of this embodiment may further include:
  • Step S106 Modify the self-discharge current threshold according to the self-discharge current of the reference battery.
  • FIG 8 is a normal distribution diagram of the self-discharge current of the reference battery.
  • Step S106 can be implemented by: obtaining the self-discharge currents of multiple reference batteries, counting the intervals in which the self-discharge currents of the reference batteries are located and the frequency of each interval, and establishing a normal distribution diagram (for example, as shown in Figure 8).
  • the horizontal axis of the distribution chart is the interval of the self-discharge current of the reference battery, and the vertical axis of the normal distribution chart is the frequency of each interval.
  • the self-discharge current threshold is designed based on the distribution of the self-discharge current of the reference battery.
  • the self-discharge current threshold can be designed to be the self-discharge current of the reference battery with the highest frequency.
  • the specific implementation method of obtaining the self-discharge currents of multiple reference batteries may refer to the above-mentioned step S1031. It should be understood that before obtaining the self-discharge currents of multiple reference batteries, the reference battery needs to be determined first.
  • the reference battery refers to the 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.
  • the reference battery can be determined by testing the K value or self-discharge rate of the battery using methods in the related art.
  • the K value of the test battery to determine the benchmark battery Taking the K value of the test battery to determine the benchmark battery as an example, first test the K value of the battery, screen out the normal batteries based on the K value, and use some of the selected normal batteries with the same model and type as the battery under test as the benchmark battery. 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.
  • step S106 can be understood as using a known and highly accurate method to screen out the reference battery, then using the detection method of this embodiment to calculate the self-discharge current of the reference battery, and correcting the self-discharge current based on the self-discharge current of the reference battery. discharge current threshold. In this way, the accuracy of screening the reference battery is high, which is conducive to reducing the impact of the design error of the self-discharge current threshold on the test results of the battery under test, and improving the test accuracy of the battery under test.
  • the self-discharge current threshold is designed not only considering the distribution of the self-discharge current of the battery under test, but also considering the self-discharge current of the reference battery, so as to improve the accuracy of the self-discharge current threshold, so that according to the comparison
  • the results can accurately determine whether the tested battery is a normal battery or an abnormal battery, reducing battery screening errors.
  • the battery detection method can also be performed as follows: Described steps:
  • Step 1 Obtain the charging data of the reference battery during the formation process.
  • Step 2 Calculate the standard value based on the test voltage range and the charging data of the reference battery.
  • the above standard power difference ⁇ Q B is the standard deviation value of the power value Q when the battery is charged from U C1 to U C2 .
  • the reference battery is a normal battery, so the difference in power value Q when the reference battery is charged from U C1 to U C2 can be regarded as the standard power difference, that is, the standard power difference ⁇ Q B can be designed to be equal to
  • the power value of the reference battery can be obtained in step 1, and its specific acquisition method is similar to that of the battery under test, 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).
  • ⁇ T B refers to the standard charging time required for a normal battery to be charged from the first endpoint voltage value U C1 of the test voltage range to the second endpoint voltage value U C2 .
  • ⁇ T B can be designed based on experience and actual working conditions. For example, when the test voltage range is (2V, 3.2V), ⁇ T B can be designed as 0.8h, 0.82h, 0.85h, 1h, etc. This embodiment does not do this limit.
  • the difference in charging time when the reference battery is charged from U C1 to U C2 can be regarded as the standard charging time ⁇ T B .
  • the detection circuit 130 is also configured to detect the charging time T (unit: h) required for charging the battery to a certain voltage value. At this time, the obtained charging data of the battery under test and the charging data of the reference battery are both (T, U, Q). In this way, the standard charging time ⁇ T B can be determined based on the charging data of the reference battery in the formation process.
  • the detection circuit 130 may include a clock chip, and the clock chip is used to measure the charging time of the battery.
  • the charging data of the reference battery are obtained as shown in Table 1.
  • Table 1 shows the charging data of battery A and battery B.
  • the following takes the test voltage range as (2V, 3.2V) as an example.
  • the charging time required for battery A to charge from 2V to 3.2V is 1.82h.
  • -1h 0.82h, then ⁇ T B can be designed as 0.82h.
  • the standard value can also be an average of the total charging current of multiple reference batteries.
  • both A battery and B battery can be used as the reference battery.
  • taking the average of the total charging current of multiple reference batteries as the standard value is beneficial to reducing the error of the referenced reference battery's total charging current. The impact brought by the test will help improve the accuracy of the test.
  • the detection method of this embodiment calculates the standard value based on the actual charging data of the reference battery in the formation process. In this way, the standard value is less prone to errors and the design is reasonable.
  • ⁇ T c can be calculated based on the charging data of the battery under test obtained in step S101 .
  • ⁇ T c can be The charging time T2 required for the battery under test to charge to the second endpoint voltage value is minus the charging time T1 required for the battery under test to charge to the first endpoint voltage value.
  • ⁇ TC can be equal to ⁇ TB
  • the total charging current of the battery under test is calculated based on the standard time required for a normal battery to charge from the first endpoint voltage value to the second endpoint voltage value. In this way, there is no need to charge the tested battery from the first endpoint voltage value. The charging time required to reach the second endpoint voltage value is calculated, which saves calculation time.
  • the self-discharge current threshold as 0mA as an example, at this time, the self-discharge current IC of battery 1 under test in Table 2 is not equal to the self-discharge current threshold, then the battery under test is judged to be abnormal and is unqualified. Battery; Similarly, if the self-discharge current I C of battery 2 under test in Table 2 is not equal to the self-discharge current threshold, the battery under test is judged to be abnormal and is also an unqualified battery.
  • step S102 the implementation method of determining the test voltage interval of the battery under test based on the charging data of the battery under test specifically includes the following execution steps:
  • Step 1021 Perform fitting according to the charging data of the battery under test to generate a formation curve of the battery under test; the formation curve includes the voltage value and the corresponding power value of the battery under test.
  • Step 1022 Determine the test voltage interval based on the slope of each point on the formation curve of the battery under test.
  • Step S101 can obtain multiple sets of charging data of the battery under test, and each set of charging data is (U, Q).
  • Step S1021 can obtain the formation curve of the battery under test by fitting multiple sets of charging data.
  • the formation curve shown in Figure 9 can be obtained by fitting.
  • the vertical axis of the formation curve represents the voltage value of the battery under test
  • the horizontal axis of the formation curve represents the power value of the battery under test.
  • FIG. 9 is a schematic diagram of the formation curve of the tested battery according to 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.
  • 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 ⁇ 4V, the tangent slope of each point on the curve segment cd is The tangent slope of the point 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 bc segment is greater than or equal to 0 and less than k1 and k2.
  • the curve segment ab can be regarded as the first non-platform area transformed into a curve
  • the curve segment bc can be regarded as the platform area transformed into a curve
  • the curve segment cd can be regarded as the second non-platform area transformed into a curve.
  • step S1022 can be to divide the formation curve into a platform area and a non-platform area according to the slope of each point on the formation curve of the battery under test, determine the voltage range corresponding to the platform area as the test voltage interval, or determine the non-platform area.
  • the corresponding voltage range is the test voltage interval.
  • the transformation function is used to characterize the transformation curve.
  • the first non-platform area can be determined. Confirm that the point with the first-order derivative greater than or equal to k2 and the smallest voltage value is the starting endpoint of the second non-platform area, and confirm that the point with the first-order derivative greater than or equal to k2 and the largest voltage value is the end endpoint of the second non-platform area, then the The second non-platform area can be determined.
  • the end endpoint of the first non-platform area is the start endpoint of the platform area
  • the start endpoint of the second non-platform area is the end endpoint of the platform area, then the platform area can be determined.
  • the point that is greater than 0 but less than k1 and k2 is the starting end point of the platform area.
  • the point where the first derivative changes from greater than 0 but less than k1 and k2 to greater than or equal to k2 is the end end point of the platform area. Then the platform area can be determined, and then A first non-platform area and a second non-platform area may be determined.
  • the first-order derivative of each point in the formation curve represents the tangent slope of the point. In this way, the detection method can divide the platform area and the non-platform area by calculating the first-order derivative.
  • the voltage range corresponding to the non-platform area can be determined as the test voltage interval.
  • the test voltage range of the battery under test at this time can be (2V, 3.2V) or (3.6V, 4V).
  • the test voltage range of the battery under test can be further designed to be included in the voltage range corresponding to the non-platform area.
  • the test voltage range of the battery under test can be (2.2V, 3V), (3.8V, 4V), etc.
  • the voltage range corresponding to the platform area can be determined as the test voltage interval.
  • the test voltage range of the battery under test at this time can be (3.2V, 3.6V).
  • the test voltage range of the battery under test can be further designed to be included in the voltage range corresponding to the platform area.
  • the test voltage range of the battery under test can be (3.3V, 3.5V V).
  • the voltage range corresponding to the non-platform area is designed as the test voltage interval.
  • the voltage difference corresponding to the non-platform area If the value is larger, the difference between the first endpoint voltage value and the second endpoint voltage value of the test voltage interval can be larger to facilitate calculation.
  • step S102 can be omitted at this time.
  • the battery detection method of this embodiment establishes a formation curve based on the charging data of the battery under test, and determines the test voltage range based on the changes in the slope of each point on the formation curve. This fully takes into account the changing characteristics of the formation curve, which is beneficial to improving test accuracy. sex.
  • two voltage values in the charging data of the battery under test can also be arbitrarily selected as the endpoint voltage values of the test voltage interval, thereby determining the test voltage interval of the battery under test.
  • 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 the internal short circuit of the battery is equivalent to the discharge caused by the series resistance of the battery, the experimental plan is to use the detection method of this embodiment to charge the unformed battery and record the charging data, and detect the battery without series resistance. The self-discharge current of the battery and the self-discharge current when a resistor is connected in series.
  • Table 3 shows the charging data of three experimental batteries. None of the three experimental batteries have been formed. Among the three experimental batteries, the S1 battery has no series resistor, the S2 battery has a series resistor and the resistance value is 100K. The S3 battery is connected in series with a resistor and the resistor value is 1M. Charge the S1 battery, S2 battery and S3 battery for formation. The test voltage range is (2V, 3.2V), and the charging time required for the three experimental batteries to charge from 2V to 3.2V is 0.87167h. Calculate three The self-discharge current of each experimental battery is shown in 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 the reference battery, and then the self-discharge current of the S2 battery can be calculated.
  • the self-discharge current of the S3 battery with a resistor with a resistance of 1M in series is not equal to that of the S1 battery. Self-discharge current.
  • Figure 10 is a schematic diagram of the voltage charging time relationship curve of a normal battery and an abnormal battery. It can be seen from Figure 4a and Figure 4b that the abnormal battery has an internal short circuit, and the positive and negative electrodes of the abnormal battery are connected to form a conductive loop 140. The electrons e - in the negative electrode of the battery will migrate to the positive electrode along the conductive loop 140, causing self-discharge. Affected by self-discharge, abnormal batteries charge slower than normal batteries at the same current, and the charging time required to reach a certain voltage value is longer. Therefore, the voltage charging time relationship during normal battery charging is shown as the solid line in Figure 10, and the voltage charging time relationship during abnormal battery charging is shown as the dotted line in Figure 10.
  • FIG 11 is a schematic flowchart of a battery detection method according to other embodiments of the present application.
  • the method includes the following steps S201 to S203.
  • Step S201 obtain the charging data of the battery under test in the formation process; the charging data includes reference parameters and parameters to be measured, where one of the reference parameters and the parameters to be measured is the voltage value, and the other is the voltage value charged to the corresponding voltage.
  • the required charging time is the charging time.
  • Step S202 Based on the charging data of the battery under test, determine the parameter value of the parameter to be measured when the reference parameter is in the interval to be estimated.
  • Step S203 Determine whether the battery under test is normal based on the comparison result between the parameter value of the battery under test and the base reference value when the reference parameter is in the range to be estimated.
  • the detection method of this embodiment also detects whether the battery under test is normal based on the charging data of the battery under test in the formation process.
  • the charging data obtained in step S201 in this example may include the voltage value U (unit: V) of the battery and the charging time T (unit: h) required for charging the battery to a certain voltage value.
  • 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 voltage value of the battery, and the clock chip is used for timing.
  • 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 battery under test 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 that may be obtained for a battery under test are (1h, 1.8V), (1.6h, 2.8V), (2h, 3.2V).
  • the baseline reference value can be understood as the value of the parameter to be measured when the reference parameter of the reference battery is in the interval to be measured.
  • the model and type of the reference battery are consistent with the battery under test, the reference battery is a normal battery, and the charging parameters (such as charging current or charging voltage) of the reference battery in the formation process are consistent with the charging parameters of the battery under test in the formation process.
  • the detection method provided in this embodiment by detecting the battery under test according to the detection method provided in this embodiment, it can be determined whether the battery under test is normal, and then abnormal batteries can be screened out. Moreover, because the charging time required for an abnormal battery with self-discharge phenomenon to be charged to a certain voltage value is longer than the charging time required for a normal battery to be charged to a certain voltage value, the detection method provided in this embodiment is by Comparing the relationship between the voltage value of the battery under test and the charging time and the voltage value of the reference battery and the charging time can be used to detect whether the self-discharge performance of the battery under test is qualified.
  • the battery process flow includes a sealing process, a formation process, a resting process, a testing process, and a capacity dividing process. That is, the battery is first put aside and then the discharge parameters of the battery are detected to test the performance of the battery.
  • This embodiment uses the charging data of the battery during the formation process to determine the performance of the battery. Therefore, the detection method provided by this embodiment can be executed after the formation process and before the resting process. Designed 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 resting process and the testing process, so as to screen out unqualified batteries in advance. In this way, there is no need to put the battery aside for a period of time, which is beneficial to shortening the battery life. Battery testing time and testing cycles improve testing efficiency, which in turn helps alleviate the pressure on battery manufacturers’ storage space and cash flow.
  • each battery can be tested for performance using its charging data in the formation process, thereby achieving full battery performance.
  • the effect of inspection is that each battery can be tested for performance, which is helpful to avoid unqualified batteries from leaving the factory.
  • 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.
  • the reference reference value at this time is the charging time of the reference battery to The charging time required for 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.
  • the interval to be estimated can be (U d1 , U d2 ), and U d1 is smaller than U d2 . In this way, the method of this embodiment uses the charging data of the battery under test in the constant current charging stage for testing, and has high detection accuracy.
  • the reference parameter can be U d1
  • the parameter to be measured is the charging time T d1 required for the battery under test to be charged to U d1 .
  • the base reference value can be designed based on experience and actual working conditions.
  • the base reference value can be the charging time T J1 required for the base battery to be charged to U d1 . Based on the comparison results between T d1 and T J1 , the target battery is judged to be charged. Check whether the battery is normal.
  • the essence of the second situation is that the charging time T d1 required for the battery to be tested to be charged to U d1 is within a time range, which is a qualified battery. Compared with comparing T d1 with a numerical value, it is helpful to reduce the detection deviation. This results in inaccurate testing.
  • the reference parameter can be U d2
  • the parameter to be measured is the charging time T d2 required to charge the battery under test to U d2
  • the reference parameter can also be any voltage value within the interval to be estimated.
  • the reference parameter is the charging time
  • the parameter to be measured is the corresponding voltage value.
  • the base reference value at this time 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 when the tested battery and the reference battery are charged under the same charging parameters and for the same length of time.
  • the interval to be estimated can be (T d1 , T d2 ), and T d1 is smaller than T d2 .
  • step S203 may be as follows:
  • Step 1 Compare the voltage value corresponding to the battery under test when the charging time is the first preset value with the first reference value to obtain the first comparison result.
  • Step 2 Compare the voltage value corresponding to the battery under test when the charging time is the second preset value with the first reference value to obtain a second comparison result.
  • Step 3 Determine whether the battery under test is normal based on the first comparison result and the second comparison result.
  • the first preset value and the second preset value may be any value within the interval to be evaluated.
  • the first preset value may be T d1 .
  • the corresponding voltage value is the voltage value U d1 reached by the battery under test when the charging time reaches T d1 .
  • the first reference value can be designed based on experience and actual working conditions.
  • the base reference value can be the voltage value reached by the base battery when the charging time is T d1 .
  • the second preset value may be T d2 . At this time, the corresponding voltage value is the voltage value U d2 reached by the battery under test when the charging time reaches T d2 .
  • Table 4 shows the charging data for battery C, battery D, and the two batteries under test.
  • the first preset value can be 48s and the second preset value can be 3000s.
  • One of the reference values is when the charging time reaches 48s, the corresponding first reference value is the corresponding voltage value 2.004V when the C battery charging time reaches 48s, the other reference value is when the charging time reaches 3000s, the corresponding second reference value That is, the corresponding voltage value is 3.164V when the C battery charging time reaches 3000s.
  • the voltage value of the tested battery 3 when the charging time reaches 48s is 1.948V. Compare it with the first reference value 2.004V. The first comparison result is that the voltage value of the tested battery 3 when the charging time reaches 48s is less than the first reference value. Reference. Compare it with the second reference value 3.164V, and obtain the second comparison result that the voltage value of the tested battery 3 when the charging time reaches 48 seconds is less than the second reference value. Both the first comparison result and the second comparison result are that when the charging time of the battery 3 under test reaches the preset value, the corresponding voltage value is less than the base reference value, and then it can be determined that the battery 3 under test is abnormal.
  • the voltage value reached by the tested battery 4 when the charging time reaches 48s is smaller than the corresponding first reference value, and the voltage value reached by the tested battery 4 when the charging time reaches 3000s is also smaller than the corresponding second reference value. , then the battery under test 4 is also different from the reference battery, and the battery under test 4 can be determined to be abnormal.
  • 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.
  • the first preset value is T d1
  • the corresponding voltage value of the battery under test is U d1 when the charging time is the first preset value.
  • the second preset value is T d2
  • the battery under test is charged for the third time.
  • the corresponding voltage value at the second preset value is U d2 .
  • ⁇ U d U d2 -U d1
  • FIG. 12 is a schematic flowchart of a modified example of the method shown in FIG. 11 . It is worth noting that, referring to Figure 12, before step S203, the detection method of this embodiment may also include the following steps:
  • Step S204 Obtain the charging data of the reference battery.
  • Step S205 According to the charging data of the reference battery, determine the parameter value of the parameter to be measured of the reference battery when the reference parameter is in the interval to be estimated.
  • Step S206 Determine the base reference value based on the parameter value of the parameter to be measured of the base battery when the reference parameter is in the interval to be estimated.
  • step S204 multiple sets of charging data of the reference battery may be obtained.
  • the purpose of step S206 is to design the benchmark reference value to be the parameter value of the parameter to be measured when the reference parameter of the benchmark battery is in the interval to be estimated. For example, in Table 4, C battery is used as the benchmark battery, and the reference parameter is that the charging time reaches 48 seconds, then the benchmark reference The value is the voltage value 2.004V reached by the reference battery after charging for 48 seconds.
  • the base reference value is designed based on the actual charging data of the base battery in the formation process. In this way, the base reference value is less prone to errors and design errors. Reasonable.
  • step S206 can be implemented in the following manner:
  • the base reference value is determined based on the average value of the parameter values to be measured of multiple reference batteries when the reference parameter is in the interval to be estimated.
  • the parameter to be measured is the average of the charging time corresponding to the voltage value of multiple reference batteries; when the reference parameter is the charging time, the parameter to be measured is the average of the charging time corresponding to the voltage value.
  • the battery is charged to the average voltage value corresponding to the charging time.
  • the parameters to be measured are the voltage value reached by the C battery when the charging time is 48s and the D battery.
  • step S203 can also be implemented by using the following steps:
  • Step 1 Establish the first relationship curve of the battery under test based on the charging data of the battery under test
  • Step 2 Establish the second relationship curve of the reference battery based on the charging data of the reference battery
  • Step 3 Determine whether the battery under test is normal based on the comparison result between the section to be estimated of the first relationship curve and the section to be estimated of the second relationship curve; wherein, the section to be estimated of the first relationship curve is the reference parameter in the first relationship curve.
  • the curve segment in the interval to be estimated, the segment to be estimated in the second relationship curve is the curve segment in the second relationship curve in which the reference parameter is in the interval to be estimated.
  • the charging data of the battery under test in step 1 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.
  • the voltage value is the vertical axis of the first relationship curve, and the charging time is the third.
  • Matlab can be used to fit multiple sets of charging data obtained in step S201 to form a first relationship curve.
  • step 2 the horizontal axis of the second relationship curve is the charging time of the reference battery, and the vertical axis is the voltage value of the reference battery.
  • the second relationship curve is formed by fitting multiple sets of charging data obtained in step S204 using Matlab. .
  • the section to be estimated of the first relationship curve in step 3 is the curve section where the reference parameter is in the interval to be estimated.
  • the first relationship curve of the battery under test can be as shown in Figure 13.
  • the reference parameter is the charging time and the interval to be estimated is Taking (48s, 3000s) as an example, at this time, the section to be estimated of the first relationship curve is the cs section.
  • the section to be estimated of the second relationship curve in step 3 is the curve section in the relationship curve of the reference battery in which the reference parameter is in the range to be estimated.
  • FIG. 13 is a schematic diagram of the first relationship curve of the battery according to some embodiments of the present application.
  • step 3 can be understood as comparing the section to be estimated of the battery under test with the section to be estimated of the reference battery. If the section to be estimated of the battery under test overlaps or is highly similar to the section to be estimated of the benchmark battery, it can be determined that the section under test is The battery is normal. If the section to be evaluated of the battery under test does not coincide with the section to be evaluated of the reference battery or the similarity is low, it can be determined that the battery under test is abnormal.
  • the relationship curve obtained by fitting the charging data of the battery under test is compared with the relationship curve obtained by fitting the charging data of the reference battery to determine whether there is an abnormality in the battery under test.
  • the detection circuit 130 can be configured to detect the voltage value, power value and charging time of the battery. Then the charging data of the battery 200 can include the voltage value U, the power value Q and the charging time T. In this way, not only can the detection methods shown in Figures 1 and 6 be used to determine whether the battery under test is qualified based on the detected voltage value U and power value Q of the battery under test, but also the testing methods shown in Figures 11 and 12 can be used.
  • the detection method determines whether the battery under test is qualified based on the detected voltage value U and charging time T of the battery under test. In general, by obtaining the charging data of the battery in the formation process, the charging data includes the voltage value U, the electric quantity value Q and the charging time T. Based on the charging data, multiple detection methods can be selected to test the battery under test.
  • the charging data may also include the electric quantity value Q when charging to the corresponding voltage value. That is to say, the charging data of the battery under test obtained in step S201 in this embodiment is (T, U, Q).
  • the method may also include the following steps:
  • Step S207 Determine the resistance value of the battery under test based on the charging data of the battery under test.
  • Step S208 Determine whether the battery under test is normal based on the comparison result between the resistance value of the battery under test and the reference resistance value.
  • the charging data (T, U, Q) of the reference battery can also be obtained by referring to step S201. 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 normal. The battery under test is abnormal.
  • 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. That is to say, the detection method of this embodiment is suitable for detecting the internal resistance performance of the battery.
  • FIG. 14 is a schematic flowchart of a battery detection method according to some further embodiments of the present application.
  • the battery detection method may include steps S301 to S313.
  • Step S301 Obtain the charging data of the battery under test in the formation process; the charging data includes the voltage value U and the corresponding electric quantity value Q.
  • Step S302 Perform fitting according to the charging data of the battery under test to generate a formation curve of the battery under test; wherein the formation curve data of the battery under test includes a voltage value of the battery under test and a corresponding power value.
  • Step S303 According to the slope of each point on the formation curve of the battery under test, the formation curve is divided into a platform area and a non-platform area, and the voltage range corresponding to the platform area is determined as the test voltage interval ( UC1 , U C2 ).
  • Step S304 Calculate the test power difference ⁇ Q C according to the charging data of the battery under test and the test voltage interval ( UC1 , U C2 ).
  • the test power difference ⁇ Q C is equal to the power value Q C2 corresponding to the battery under test charged to U C2 minus the power value Q C1 corresponding to the charge to U C1 .
  • Step S305 Obtain the charging data of the reference battery in the formation process; the charging data includes the voltage value U, the corresponding power value Q and the charging time.
  • Step S306 Calculate the standard power difference ⁇ Q B and the standard charging time ⁇ T B according to the charging data of the reference battery and the test voltage interval ( UC1 , UC2 ).
  • the standard power difference ⁇ Q B is equal to the power value Q C2 corresponding to the reference battery charged to U C2 minus the power value Q C1 corresponding to the charge to U C1 .
  • the standard charging time ⁇ T B is equal to the charging time required for the reference battery to be charged to U C2 Subtract the charging time required to charge to U C1 .
  • Step S307 Calculate the total charging current I of the battery under test and the total charging current I of the reference battery based on the test power difference ⁇ Q C , the standard power difference ⁇ Q B and the standard charging time ⁇ T B .
  • I measured total ⁇ Q C ⁇ ⁇ T B
  • I standard total ⁇ Q B ⁇ ⁇ T B .
  • Step S309 Repeat steps S301 to step S308 to obtain the self-discharge current IC self-discharge of multiple batteries under test.
  • Step S310 Determine a self-discharge current threshold based on the distribution of self-discharge currents of multiple batteries under test.
  • Step S311 Compare the self-discharge current of each tested battery with the self-discharge current threshold, and determine whether the tested battery is normal based on the comparison result.
  • Step S312 Obtain the charging data of the normal battery in the formation process based on the test results of the voltage drop method.
  • Step S313 Calculate the self-discharge current of each normal battery based on the charging data of the normal battery in S312, and adjust the self-discharge current threshold based on the distribution of the self-discharge current of the normal battery.
  • step S301 and step S305 is not specifically limited.
  • FIG. 15 is a schematic structural diagram of a battery detection device 300 according to some embodiments of the present application.
  • the battery detection device 300 includes: a data acquisition module 310 , a determination module 320 and a judgment module 330 .
  • the data acquisition module 310 is used to obtain the charging data of the battery under test in the formation process; the charging data includes the voltage value and the corresponding power value; the determination module 320 is used to determine the battery under test based on the charging data of the battery under test. Test the voltage range and the measured value; the judgment module 330 is used to judge whether the battery under test is normal based on the measured value and the standard value.
  • the measured value is the test power difference
  • the test power difference is the difference in power value when the battery under test is charged from the first endpoint voltage value of the test voltage interval to the second endpoint voltage value of the test voltage interval
  • the standard value is the standard deviation value of the power value of the reference battery when it is charged from the first endpoint voltage value of the test voltage interval to the second endpoint voltage value of the test voltage interval.
  • the measured value is the total charging current of the battery under test
  • the standard value is the total charging current of the reference battery
  • 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, based on Compare the results to determine whether the battery under test is normal.
  • the data acquisition module 310 is further configured to acquire multiple batteries under test before comparing the self-discharge current and the self-discharge current threshold of the battery under test to obtain a comparison result, and determining whether the battery under test is normal based on the comparison result.
  • the self-discharge current; the determination module 320 is further configured to determine the self-discharge current threshold according to the distribution of self-discharge currents of the plurality of batteries under test.
  • the battery detection device 300 also includes a correction module.
  • the correction module is used to 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. , the self-discharge current threshold is corrected based on the self-discharge current of the reference battery.
  • the data acquisition module 310 is further configured to obtain the charging data of the reference battery in the formation process before determining whether the battery under test is normal based on the measured value and the standard value; the determination module 320 is further configured to obtain charging data based on the test The voltage range and the charging data of the reference battery are used to calculate the standard value.
  • the determination module 320 is further configured to perform fitting according to the charging data of the battery under test and 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; according to The slope of each point on the formation curve of the battery under test determines the test voltage range.
  • an embodiment of the present application also provides a battery detection device 300 .
  • the battery detection device 300 includes: a data acquisition module 310 , a determination module 320 and a judgment module 330 .
  • the data acquisition module 310 is used to obtain the charging data of the battery under test in the formation process; the charging data includes reference parameters and parameters to be measured, where one of the reference parameters and the parameters to be measured is the voltage value, and the other is the charging value.
  • the charging time required to reach the corresponding voltage value; the determination module 320 is used to determine the parameter value of the parameter to be tested when the reference parameter is in the interval to be estimated according to the charging data of the battery to be tested; the judgment module 330 is used to determine the parameter value according to the charging data of the battery to be tested.
  • the parameter value of the battery under test is compared with the baseline reference value when the reference parameter is in the range to be estimated to determine whether the battery under test is normal.
  • 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 the first preset value with the first reference value. Obtain the first comparison result; compare the voltage value corresponding to the tested battery when the charging time is the second preset value with the second reference value to obtain the second comparison result; judge the tested battery based on the first comparison result and the second comparison result. Is the battery normal?
  • 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 0.5V.
  • the data acquisition module 310 is further configured to determine whether the battery under test is normal based on the comparison result of the parameter value of the battery under test when the reference parameter is in the interval to be estimated and the baseline reference value, Obtain the charging data of the reference battery; the determination module 320 is further configured to determine, based on the charging data of the reference battery, the parameter value of the parameter to be measured of the reference battery when the reference parameter is in the interval to be estimated; the determination module 330 is further configured to determine the parameter value of the reference battery based on the charging data of the reference battery. The parameter value of the parameter to be measured when the reference parameter is in the interval to be estimated determines the base reference value.
  • the determination module 320 is further configured to determine the base reference value based on an average of the parameter values of the parameters to be measured of the plurality of reference batteries when the reference parameters are in the interval to be evaluated.
  • the judgment module 330 is further configured to establish a first relationship curve of the tested battery based on the charging data of the tested battery; establish a second relationship curve of the reference battery based on the charging data of the reference battery; based on the first The comparison result between the to-be-evaluated section of the relationship curve and the to-be-evaluated section of the second relationship curve is used to determine whether the battery under test is normal; wherein, the to-be-evaluated section of the first relationship curve is the curve in which the reference parameter in the first relationship curve is in the to-be-evaluated interval.
  • segment, the segment to be estimated of the second relationship curve is the curve segment in the second relationship curve in which the reference parameter is in the interval to be estimated.
  • the charging data also includes the electric quantity value when charging to the corresponding voltage value; the determination module 320 is further configured to, after the data acquisition module 310 obtains the charging data of the battery under test in the formation process, according to the battery under test.
  • the charging data is used to determine the resistance value of the battery under test; the determination module 330 is further configured to determine whether the battery under test is normal based on the comparison result between the resistance value of the battery under test and the reference resistance value.
  • FIG 16 is a schematic structural diagram of an electronic device according to some embodiments of the present application.
  • an embodiment of the present application also provides an electronic device, including: a memory 401 and at least one processor 402.
  • Memory 401 is used to store program instructions.
  • the processor 402 is configured to implement the battery detection method in this embodiment when the program instructions are executed.
  • 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 may be an integrated interface integrating input and output. Among them, the output interface is used to output data, and the input interface is used to obtain input data.
  • One embodiment of the present application provides a computer-readable storage medium.
  • Execution instructions are stored in the readable storage medium.
  • the computer-readable storage medium can be ROM, random access memory 401 (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage device, etc.
  • the present application provides a computer program product, including a computer program.
  • the computer program is executed by the processor 402 to implement the battery detection method provided in any one of the embodiments corresponding to FIG. 1 and FIG. 14 of the present application.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Secondary Cells (AREA)

Abstract

La présente demande concerne un procédé de test de batterie, un appareil, un dispositif, un support de stockage et un produit programme. Le procédé de test de batterie comprend les étapes consistant à : acquérir des données de charge d'une batterie testée pendant un processus de formation, les données de charge comprenant une valeur de tension et une valeur de puissance correspondante ; en fonction des données de charge de la batterie testée, déterminer un intervalle de tension de test et la valeur mesurée de la batterie testée ; et, en fonction de la valeur mesurée et d'une valeur standard, déterminer si la batterie testée est normale. Par conséquent, grâce au procédé de test, les performances des batteries peuvent être testées au moyen des données de charge pendant le processus de formation, avant un processus de maintien et un processus de test au cours de la fabrication des batteries, de façon à éliminer à l'avance les batteries non satisfaisantes. Ainsi les batteries n'ont-elles pas à être placées pendant une période de temps, ce qui contribue à raccourcir le temps de test et les cycles de test des batteries.
PCT/CN2022/110933 2022-08-08 2022-08-08 Procédé de test de batterie, appareil, dispositif, support de stockage et produit programme WO2024031261A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/110933 WO2024031261A1 (fr) 2022-08-08 2022-08-08 Procédé de test de batterie, appareil, dispositif, support de stockage et produit programme

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/110933 WO2024031261A1 (fr) 2022-08-08 2022-08-08 Procédé de test de batterie, appareil, dispositif, support de stockage et produit programme

Publications (1)

Publication Number Publication Date
WO2024031261A1 true WO2024031261A1 (fr) 2024-02-15

Family

ID=89850278

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/110933 WO2024031261A1 (fr) 2022-08-08 2022-08-08 Procédé de test de batterie, appareil, dispositif, support de stockage et produit programme

Country Status (1)

Country Link
WO (1) WO2024031261A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117829097A (zh) * 2024-02-29 2024-04-05 双一力(宁波)电池有限公司 电池数据处理方法、装置、电子设备及可读存储介质
CN118151019A (zh) * 2024-05-08 2024-06-07 北汽福田汽车股份有限公司 动力电池异常识别方法、装置、存储介质及车辆

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1340874A (zh) * 2000-05-23 2002-03-20 佳能株式会社 检测可再充电电池内部状态的方法、装置和带有该装置的设备
US20190004120A1 (en) * 2015-08-13 2019-01-03 Charged Engineering Inc. Methods and systems for determining battery charge or formation completeness
CN110888072A (zh) * 2019-11-28 2020-03-17 Oppo广东移动通信有限公司 电池微短路的检测方法及装置、电子设备
US20220043068A1 (en) * 2018-10-05 2022-02-10 Lg Chem, Ltd. Method and apparatus for diagnosing low voltage of secondary battery cell
WO2022145776A1 (fr) * 2020-12-28 2022-07-07 주식회사 엘지에너지솔루션 Appareil et procédé de diagnostic d'une batterie secondaire

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1340874A (zh) * 2000-05-23 2002-03-20 佳能株式会社 检测可再充电电池内部状态的方法、装置和带有该装置的设备
US20190004120A1 (en) * 2015-08-13 2019-01-03 Charged Engineering Inc. Methods and systems for determining battery charge or formation completeness
US20220043068A1 (en) * 2018-10-05 2022-02-10 Lg Chem, Ltd. Method and apparatus for diagnosing low voltage of secondary battery cell
CN110888072A (zh) * 2019-11-28 2020-03-17 Oppo广东移动通信有限公司 电池微短路的检测方法及装置、电子设备
WO2022145776A1 (fr) * 2020-12-28 2022-07-07 주식회사 엘지에너지솔루션 Appareil et procédé de diagnostic d'une batterie secondaire

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117829097A (zh) * 2024-02-29 2024-04-05 双一力(宁波)电池有限公司 电池数据处理方法、装置、电子设备及可读存储介质
CN117829097B (zh) * 2024-02-29 2024-05-28 双一力(宁波)电池有限公司 电池数据处理方法、装置、电子设备及可读存储介质
CN118151019A (zh) * 2024-05-08 2024-06-07 北汽福田汽车股份有限公司 动力电池异常识别方法、装置、存储介质及车辆

Similar Documents

Publication Publication Date Title
WO2024031261A1 (fr) Procédé de test de batterie, appareil, dispositif, support de stockage et produit programme
Zhang et al. Study on battery pack consistency evolutions and equilibrium diagnosis for serial-connected lithium-ion batteries
US9759779B2 (en) State of charge estimation device and method of estimating state of charge
CN204269787U (zh) 一种锂离子电池低温性能一致性的检测系统
CN103995232B (zh) 一种磷酸铁锂动力电池组峰值充放电性能的检测方法
TWI464935B (zh) 電池模組
CN104316877A (zh) 一种磷酸铁锂电池的自放电检测方法
CN113533981B (zh) 锂离子电池自放电检测方法、设备及计算机可读存储介质
CN115825774A (zh) 电池的检测方法、装置、设备、存储介质和程序产品
CN113811781A (zh) 电池诊断装置和方法
KR20200101754A (ko) 배터리 제어 장치 및 배터리 제어 방법
JP2022532545A (ja) 電池セル診断装置および方法
JP2014007025A (ja) 診断装置および診断方法
CN117154268B (zh) 一种基于水系钠离子储能电池柜的soc校正方法、装置、设备及存储介质
CN116184235B (zh) 电池自放电性能的检测方法和装置
CN115754736A (zh) 一种储能系统充放电末端的soc校准方法及装置
CN103901353B (zh) 锂离子电池组各电芯一致性的判断方法与定时测量电压仪
TW201524077A (zh) 電池健康狀態分析方法
CN113238152A (zh) 锂电池自放电检测方法
KR101954285B1 (ko) 상태 관리 장치, 축전 소자의 균등화 방법
CN106249165A (zh) 一种单体铅酸蓄电池优劣判定的测试方法
JP7416982B2 (ja) バッテリーを診断するための装置及びその方法
CN115343639A (zh) 电池自放电的测试方法
US20220278540A1 (en) Battery charge and discharge control device and method
CN117169739A (zh) 一种锂离子电池的内阻性能的测评方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22954241

Country of ref document: EP

Kind code of ref document: A1