A soft package lithium battery edge voltage testing device and method

Abstract

This application relates to the field of lithium battery technology, and in particular to a device and method for testing the edge voltage of a pouch lithium battery. The device includes a puncture probe, a first voltage probe, a second voltage probe, a simulated module voltage source, a data acquisition unit, and a control unit. The puncture probe is used to puncture the aluminum layer contact between the pouch lithium battery under test and the aluminum-plastic film. The first voltage probe is used to contact the positive electrode tab. The second voltage probe is used to contact the negative electrode tab. The simulated module voltage source is connected in series in the test circuit between the puncture probe and the first or second voltage probe. The control unit is used to control the corresponding probe action according to the edge voltage test type and to continuously acquire measured edge voltage values ​​at multiple time points to determine whether the edge voltage state of the pouch lithium battery under test is normal. Thus, by acquiring measured edge voltage values ​​at multiple time points and connecting the simulated module voltage source in series in the test circuit, this application can improve the accuracy and stability of the test results.

Description

Technical Field

[0001] This application relates to the field of lithium battery technology, and in particular to a device and method for testing the side voltage of a pouch lithium battery. Background Technology

[0002] Soft-pack lithium batteries use an aluminum-plastic film as the packaging shell, and their interior consists of a positive electrode, a negative electrode, a separator, and an electrolyte. During battery manufacturing and long-term use or storage, if the PP layer of the aluminum-plastic film has microscopic capillary pore defects, the electrolyte may penetrate between the aluminum layer and the negative electrode, thus forming an ion conduction path and causing corrosion of the aluminum-plastic film (commonly known as "black spots" or internal corrosion). In severe cases, this can lead to battery leakage or fire.

[0003] Currently, the industry commonly uses "edge voltage" testing as the primary method for screening corrosion risks of aluminum-plastic films. Edge voltage typically refers to the voltage difference between the aluminum layer of the aluminum-plastic film and the positive or negative electrode of the battery. Existing testing methods are usually single-point tests, where the device reads an instantaneous voltage value after the probe contacts the electrode tab and compares it with a preset threshold to determine whether it passes or fails. However, due to differences in the actions of different devices or the delays of programmable logic controllers (PLCs), the actual data acquisition time points are inconsistent. This results in significant fluctuations in the edge voltage values ​​measured for the same battery at different devices or at different time points, leading to poor accuracy and consistency of the test results. In other words, the single-point testing method suffers from unstable test values.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] In view of this, the embodiments of this application provide at least one device and method for testing the side voltage of a pouch lithium battery, which can improve the accuracy and stability of the test results.

[0006] This application mainly includes the following aspects: In a first aspect, embodiments of this application provide a side voltage testing device for a soft-pack lithium battery, the device comprising a puncture probe, a first voltage probe, a second voltage probe, an analog module voltage source, a data acquisition unit, and a control unit; The piercing probe is used to pierce the aluminum-plastic film of the soft-pack lithium battery under test, making contact with the aluminum layer of the aluminum-plastic film; the first voltage probe is used to contact the positive electrode tab of the soft-pack lithium battery under test during positive electrode side voltage testing; the second voltage probe is used to contact the negative electrode tab of the soft-pack lithium battery under test during negative electrode side voltage testing; the analog module voltage source is connected in series in the test circuit, and the test circuit is the circuit between the piercing probe and the first voltage probe or the second voltage probe; the data acquisition unit is electrically connected to the piercing probe, the first voltage probe, the second voltage probe, and the analog module voltage source; the control unit is connected to the data acquisition unit and the driving mechanism of each probe. The control unit is used to control the corresponding probe action according to the side voltage test type, and to continuously collect the measured side voltage value at multiple time points to determine whether the side voltage state of the soft-pack lithium battery under test is normal.

[0007] Secondly, embodiments of this application also provide a method for testing the side voltage of a pouch lithium battery, the method comprising: The soft-pack lithium battery under test is placed on the support platform of the soft-pack lithium battery side voltage testing device, so that the positive electrode tab, negative electrode tab and aluminum-plastic film side sealing area of ​​the soft-pack lithium battery under test are exposed to the action area of ​​the corresponding probe respectively. The first voltage probe is controlled to form a stable electrical contact with the surface of the positive electrode tab, the second voltage probe is controlled to form a stable electrical contact with the surface of the negative electrode tab, and the piercing probe is controlled to contact the aluminum layer of the aluminum-plastic film side seal. In response to the probe contact status signal, the measured terminal voltage value is acquired at multiple time points. The measured terminal voltage values ​​collected at each time point are compared with the corresponding standard voltage threshold range, and the side voltage test judgment result of the soft-pack lithium battery under test is output.

[0008] Thirdly, embodiments of this application also provide an electronic device, including: a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor communicates with the memory through the bus. The machine-readable instructions are executed by the processor to perform the steps of the side voltage testing method for a soft-pack lithium battery as described in the second aspect or any possible implementation of the second aspect.

[0009] Fourthly, embodiments of this application also provide a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps of the side voltage testing method for a pouch lithium battery as described in the second aspect or any possible implementation of the second aspect.

[0010] This application provides a device and method for testing the edge voltage of a pouch lithium battery. The device includes a puncture probe, a first voltage probe, a second voltage probe, a simulated module voltage source, a data acquisition unit, and a control unit. The puncture probe is used to puncture the aluminum layer contact between the pouch lithium battery under test and the aluminum-plastic film. The first voltage probe is used to contact the positive electrode tab, and the second voltage probe is used to contact the negative electrode tab. The simulated module voltage source is connected in series in the test circuit between the puncture probe and the first or second voltage probe. The control unit is used to control the corresponding probe action according to the edge voltage test type and to continuously collect measured data at multiple time points. The side voltage value is used to determine whether the side voltage state of the soft-pack lithium battery under test is normal. Compared with the single-point test in the prior art, which has poor accuracy and consistency due to large fluctuations in the side voltage value measured by the same battery at different devices or at different time points, this application collects the measured side voltage value at multiple time points, making the test results repeatable and comparable. At the same time, by connecting an analog module voltage source in series in the test circuit, the weak side voltage signal can be raised to a range much higher than the system noise, which greatly improves the resolution and detection rate of ion conduction leakage, thereby improving the accuracy and stability of the test results.

[0011] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This paper shows a functional block diagram of a side voltage testing device for a soft-pack lithium battery provided in an embodiment of this application; Figure 2 A flowchart of a side voltage testing method for a soft-pack lithium battery provided in an embodiment of this application is shown; Figure 3 A flowchart of another method for testing the side voltage of a soft-pack lithium battery provided in an embodiment of this application is shown; Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown.

[0014] Explanation of key component symbols: In the diagram: 100 - Side voltage testing device for soft-pack lithium battery; 110 - Puncture probe; 120 - First voltage probe; 130 - Second voltage probe; 140 - Simulated module voltage source; 150 - Data acquisition unit; 160 - Control unit; 400 - Electronic equipment; 410 - Processor; 420 - Memory; 430 - Bus. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0016] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0017] To enable those skilled in the art to use the content of this application, and in conjunction with the specific application scenario of "side voltage testing of soft-pack lithium batteries", the following implementation methods are provided. For those skilled in the art, the general principles defined herein can be applied to other embodiments and application scenarios without departing from the spirit and scope of this application.

[0018] The methods, apparatus, electronic devices, or computer-readable storage media described in this application can be applied to any scenario requiring edge voltage testing of pouch lithium batteries. This application does not limit the specific application scenario, and any scheme using the edge voltage testing apparatus and method for pouch lithium batteries provided in this application is within the protection scope of this application.

[0019] It is worth noting that prior to this application, existing testing methods were typically single-point tests. This involved the device reading an instantaneous voltage value after the probe contacted the electrode tab and comparing it to a preset threshold to determine pass or fail. However, due to differences in the actions of different devices or the delays of programmable logic controllers, the actual data acquisition time points were inconsistent. This resulted in significant fluctuations in the edge voltage values ​​measured for the same battery at different devices or time points, leading to poor accuracy and consistency of the test results. In other words, the single-point testing method suffered from unstable test values.

[0020] To address the aforementioned issues, this application provides a device and method for testing the edge voltage of a pouch lithium battery. The device includes a puncture probe, a first voltage probe, a second voltage probe, a simulated module voltage source, a data acquisition unit, and a control unit. The puncture probe is used to puncture the aluminum layer contact between the pouch lithium battery under test and the aluminum-plastic film. The first voltage probe is used to contact the positive electrode tab. The second voltage probe is used to contact the negative electrode tab. The simulated module voltage source is connected in series in the test circuit between the puncture probe and the first or second voltage probe. The control unit controls the corresponding probe action according to the edge voltage test type and continuously acquires measured edge voltage values ​​at multiple time points to determine whether the edge voltage state of the pouch lithium battery under test is normal. Thus, by acquiring measured edge voltage values ​​at multiple time points and connecting the simulated module voltage source in series in the test circuit, this application can improve the accuracy and stability of the test results.

[0021] To facilitate understanding of this application, the technical solutions provided in this application will be described in detail below with reference to specific embodiments.

[0022] Figure 1 This is a functional block diagram of a side voltage testing device 100 for a soft-pack lithium battery provided in an embodiment of this application. Figure 1 As shown, the edge voltage testing device 100 for soft-pack lithium batteries provided in this application embodiment is used to test the insulation performance and internal corrosion risk of the battery after the lithium battery is resealed and before shipment. The edge voltage testing device 100 for soft-pack lithium batteries includes a puncture probe 110, a first voltage probe 120, a second voltage probe 130, an analog module voltage source 140, a data acquisition unit 150, and a control unit 160.

[0023] It should be noted that the piercing probe 110 is used to pierce the aluminum-plastic film of the soft-pack lithium battery under test, achieving reliable electrical contact with the aluminum layer of the aluminum-plastic film and forming a key access point for the side voltage test circuit. One end of the piercing probe 110 is connected to the data acquisition unit 150, and the other end, after penetrating the PP layer of the aluminum-plastic film during testing, makes stable contact with the aluminum layer, thereby reliably introducing the side voltage signal between the aluminum layer, electrolyte, and electrode tab into the side voltage test device 100 of the soft-pack lithium battery.

[0024] Here, the edge voltage testing device 100 for a pouch lithium battery provided in this embodiment includes a first voltage probe 120 and a second voltage probe 130, corresponding to two edge voltage testing types: positive electrode edge voltage testing and negative electrode edge voltage testing. The two are performed independently and cannot be performed simultaneously. The first voltage probe 120 (positive electrode probe) is dedicated to positive electrode edge voltage testing and contacts the positive electrode tab of the pouch lithium battery under test during testing, forming a positive electrode side voltage testing circuit. One end of the first voltage probe 120 is connected to the data acquisition unit 150, and the other end is stably pressed against the surface of the positive electrode tab during testing to ensure a low-impedance electrical connection, reliably introducing the voltage signal between the positive electrode and the aluminum layer into the edge voltage testing device 100 for the pouch lithium battery. The second voltage probe 130 (negative electrode probe) is dedicated to negative electrode side voltage testing and contacts the negative electrode tab of the soft-pack lithium battery under test during testing, forming a negative electrode side voltage testing circuit. One end of the second voltage probe 130 is connected to the data acquisition unit 150, and the other end is stably pressed against the surface of the negative electrode tab during testing to ensure contact repeatability and signal integrity, and reliably introduce the voltage signal between the negative electrode and the aluminum layer into the side voltage testing device 100 of the soft-pack lithium battery.

[0025] Furthermore, existing solutions typically measure the absolute value of the edge voltage between the aluminum layer of the soft-pack lithium battery under test and the positive / negative electrode tabs. This voltage is often in the millivolt range, resulting in an extremely weak signal that is easily masked by the inherent noise floor, temperature drift, and AD conversion accuracy of the testing device, leading to missed detection of weak anomalies such as ion conduction. While difficult to detect effectively in single-cell testing, this anomaly is amplified by the high total voltage environment of the battery module after the cells are connected in series, potentially causing safety accidents. Existing methods lack active enhancement mechanisms for weak anomalous signals, relying solely on improving measurement accuracy, which cannot overcome the limitations of the system's inherent noise floor. In response, this application's embodiment connects an adjustable and stable analog module voltage source 140 in series with the original test circuit formed by the puncture probe 110 and the first voltage probe 120 (for positive electrode edge voltage testing) or the second voltage probe 130 (for negative electrode edge voltage testing). This analog module voltage source 140 can form a series structure with the voltmeter.

[0026] At this point, the terminal voltage actually measured by the data acquisition unit 150 (i.e., the measured terminal voltage value) is the sum of the simulated voltage value of the analog module voltage source 140 and the actual side voltage value, rather than simply measuring the original actual side voltage value. The essence of the design of this embodiment is not to improve the absolute accuracy of voltage measurement, but to raise the weak side voltage signal, which was originally at the millivolt level, to the voltage level set by the analog module voltage source 140 (e.g., 24V, 48V), so that its operating point is far away from the system noise-sensitive area near zero voltage, thereby significantly improving the test device's ability to identify changes in actual side voltage (e.g., ±5mV) and its signal-to-noise ratio. More importantly, the voltage value of the analog module voltage source 140 is set according to the operating voltage platform of the soft-pack lithium battery in the actual battery module, so that the test environment of a single cell is consistent with its high-voltage electrical stress scenario in the module, truly achieving "unified test conditions and application conditions". This allows for the early exposure of aluminum-plastic film corrosion hazards that only accelerate their evolution and cause safety risks under the high-voltage environment of the battery module at the cell stage.

[0027] In addition, the data acquisition unit 150 is electrically connected to the puncture probe 110, the first voltage probe 120, the second voltage probe 130, and the analog module voltage source 140. The data acquisition unit 150 can be a high-precision digital voltmeter or an industrial control acquisition card with an integrated AD module. It forms a complete circuit with each probe and the analog module voltage source 140, and is responsible for acquiring and outputting the measured terminal voltage value after the rise according to the instruction timing.

[0028] Here, the control unit 160 is connected to the data acquisition unit 150 and the driving mechanism of each probe. The control unit 160 is used to control the corresponding probe action according to the side voltage test type, and to continuously acquire the measured side voltage value at multiple time points to determine whether the side voltage state of the soft-pack lithium battery under test is normal. The control unit 160 can be a PLC or an embedded industrial control computer with built-in test logic program. The control unit 160 monitors the contact conduction signal of the first voltage probe 120 (positive electrode probe) or the second voltage probe 130 (negative electrode probe) in real time. After confirming that any probe is stably connected to the corresponding electrode tab, it starts the data acquisition process and simultaneously controls the piercing probe 110 to complete the aluminum layer contact, ensuring that the positive or negative side voltage test circuit is reliably established and multi-point voltage acquisition is performed.

[0029] It should be noted that, from a microscopic perspective, the aluminum-plastic film (aluminum layer / PP layer), electrolyte, separator, and negative electrode together constitute an electrochemically active micro-battery-capacitor coupled system. The moment the probe contacts the system, a discharge response is triggered, causing the edge voltage to decay non-linearly over time. The mainstream industry method uses "single-point testing," recording only a single instantaneous voltage value. This is essentially a static snapshot, failing to reflect the dynamic decay process. Furthermore, differences in equipment mechanical response and inconsistent PLC control delays cause drift in the actual sampling time, resulting in large dispersion of results for the same battery across different devices or multiple tests, leading to poor repeatability and cross-device comparability. Because the edge voltage inherently possesses decay properties, single-point measurements provide insufficient information, making it difficult to distinguish between normal slow decay and abnormally rapid decay caused by ion conduction. Crucially, such millivolt-level anomaly signals are easily masked by system noise, temperature drift, and AD accuracy during single-cell testing, leading to missed detection. However, in practical applications, when cells are connected in series to form battery modules, the high total voltage environment significantly amplifies this weak leakage effect, inducing accelerated corrosion of the aluminum-plastic film and even thermal runaway, resulting in safety accidents. Existing technologies rely solely on directly measuring the original edge voltage, lacking an active amplification mechanism for weak anomaly signals, making early, accurate, and robust risk identification difficult.

[0030] In response, this application upgrades the test from "static measurement" to "dynamic process recording". By controlling the timing, multi-point continuous sampling is achieved, and the voltage decay curve is completely captured. It can accurately identify the abnormal fast decay characteristics caused by ion conduction (micro short circuit), and fundamentally overcome the inherent defect of insufficient information in single-point measurement.

[0031] In addition, the side voltage testing device 100 for pouch lithium batteries also includes a test stand for holding the pouch lithium battery under test.

[0032] It should also be noted that the edge voltage testing method for pouch lithium batteries provided in this application includes positive electrode edge voltage testing and negative electrode edge voltage testing, and the testing logic for both is the same. Specifically, the positive and negative electrode connection method of the analog module voltage source 140 connected in series in the test circuit varies depending on the test object. Specifically, when testing the positive electrode edge voltage, the positive electrode of the analog module voltage source 140 is connected to the positive electrode tab of the pouch lithium battery under test, and the negative electrode of the analog module voltage source 140 is connected to the piercing probe 110 (aluminum layer); when testing the negative electrode edge voltage, the positive electrode of the analog module voltage source 140 is connected to the piercing probe 110 (aluminum layer), and the negative electrode of the analog module voltage source 140 is connected to the negative electrode tab of the pouch lithium battery under test.

[0033] In one possible implementation, such as Figure 1As shown, when performing a positive electrode voltage test, the positive terminal of the simulation module voltage source 140 is connected to the positive electrode tab of the soft-pack lithium battery under test, and the negative terminal of the simulation module voltage source 140 is connected to the piercing probe 110; the control unit 160 is specifically used to drive the piercing probe 110 to press down and pierce the aluminum-plastic film and form electrical contact with the aluminum layer, and at the same time, drive the first voltage probe 120 to press down and contact the positive electrode tab of the soft-pack lithium battery under test.

[0034] In one possible implementation, such as Figure 1 As shown, when performing a negative electrode voltage test, the positive terminal of the analog module voltage source 140 is connected to the piercing probe 110, and the negative terminal of the analog module voltage source 140 is connected to the negative electrode tab of the soft-pack lithium battery under test; the control unit 160 is specifically used to drive the piercing probe 110 to press down and pierce the aluminum-plastic film and form electrical contact with the aluminum layer, and at the same time, drive the second voltage probe 130 to press down and contact the negative electrode tab of the soft-pack lithium battery under test.

[0035] In one possible implementation, such as Figure 1 As shown, the measured terminal voltage value collected at any time point is the sum of the actual side voltage of the soft-pack lithium battery under test and the simulated voltage value of the simulated module voltage source 140; wherein, the simulated voltage value is set according to the total voltage of the battery module formed by multiple soft-pack lithium batteries under test connected in series in the actual application scenario, or the working voltage corresponding to a single soft-pack lithium battery under test.

[0036] Here, the simulated voltage value of the simulated module voltage source 140 is set according to the equivalent working voltage platform of a single cell corresponding to the nominal total voltage of a battery module composed of multiple soft-pack lithium batteries under test connected in series in actual application scenarios (for example, when the nominal total voltage of the module is 48V, the simulated voltage value is set to 24V or 48V, which represents the typical bias potential actually borne by the cell in the module), or according to the working voltage (such as a 3.7V steady-state platform) of a single soft-pack lithium battery under test. The simulated voltage value is adjustable in the range of 3.7V to 100V to ensure that the electrical stress applied by the test circuit is consistent with the working environment of the cell in the real module, thereby raising the real side voltage anomaly signal at the millivolt level to a high signal-to-noise ratio range, significantly improving the sensitivity and reliability of early aluminum-plastic film corrosion risk identification.

[0037] In one possible implementation, such as Figure 1 As shown, the control unit 160 is specifically used to collect the measured terminal voltage value according to the following steps: after the first voltage probe 120 or the second voltage probe 130 is pressed down and triggers the contact signal, after a first preset time, the initial measured terminal voltage value is collected.

[0038] In practical implementation, during edge voltage testing, the driving probe 110 is pressed down to pierce the aluminum-plastic film and form a stable electrical contact with the aluminum layer; simultaneously, the first voltage probe 120 (or the second voltage probe 130) is pressed down to contact the corresponding battery tab. Once the corresponding voltage probe is pressed down and triggers a contact signal, the control unit 160 does not immediately acquire the voltage, but delays for a first preset time. This first preset time can be from 100ms to 800ms. This delay allows the electrical signal oscillation after the probe contacts the tab to stabilize, and allows the micro-battery system composed of the aluminum layer, electrolyte, and negative electrode to enter a relatively stable discharge range, reducing the impact of inconsistent acquisition starting points caused by differences in the response speed of PLCs, etc.

[0039] In one possible implementation, such as Figure 1 As shown, the control unit 160 is further configured to: after acquiring the initial measured terminal voltage value, acquire a subsequent preset number of measured terminal voltage values ​​sequentially at a fixed second preset time interval.

[0040] In specific implementation, after a first preset time delay, voltage acquisition is initiated, and the current acquired voltage value is recorded as the initial measured terminal voltage value V0. Subsequently, subsequent measured terminal voltage values ​​V1, V2, ..., Vi, ..., Vn are continuously acquired at fixed second preset time intervals. In this way, by fixing the first and second preset time delays, the acquisition time point drift caused by the difference in equipment PLC delay is eliminated, making the test results repeatable and comparable.

[0041] The second preset time is between 50ms and 200ms. The total number of time points n collected can be selected as 7-12, that is, a total of 8-13 measured terminal voltage values ​​are collected.

[0042] Here, since the analog voltage value of the analog module voltage source 140 is a constant value, the change in the measured terminal voltage value over time is exactly the same as the change in the actual terminal voltage. However, the absolute value of the measured terminal voltage value is raised to near the analog voltage value of the analog module voltage source 140, far away from the noise range near zero.

[0043] In one possible implementation, such as Figure 1As shown, the control unit 160 is further configured to determine whether the side voltage test of the pouch lithium battery under test is qualified according to the following steps: for each time point, the measured terminal voltage value collected at the time point is compared with the standard voltage threshold range corresponding to the time point; if the measured terminal voltage value collected at any time point exceeds the corresponding standard voltage threshold range, the side voltage test of the pouch lithium battery under test is determined to be unqualified; if the measured terminal voltage values ​​collected at all the time points are within their respective standard voltage threshold ranges, the side voltage test of the pouch lithium battery under test is determined to be qualified.

[0044] In practical implementation, when determining the pass / failability of the edge voltage test, the control unit 160 compares the measured edge voltage value at each sampling time point with the preset standard voltage threshold range (including the upper and lower standard voltage thresholds) at that time point in a time-series manner. If the measured edge voltage value at any time exceeds the corresponding standard voltage threshold range, the edge voltage test is deemed unqualified. Only when the measured edge voltage values ​​at all sampling time points fall within their respective matched standard voltage threshold ranges is the edge voltage test considered qualified. This determination mechanism reflects the dual requirements of time sensitivity and tolerance consistency, avoiding misjudgment caused by a single transient anomaly and preventing long-term drift and escape detection, significantly improving the accuracy and robustness of voltage stability assessment in the edge region of pouch lithium batteries.

[0045] Here, the reasons for failing the side voltage test include, but are not limited to: (1) abnormal side voltage decay caused by the ion conduction path; (2) poor contact of the soft-pack lithium battery under test, that is, voltage sequence instability caused by poor contact between the probe and the aluminum layer or the tab, specifically manifested as irregular jumps, open circuits, discontinuous connections and other abnormal forms.

[0046] In one possible implementation, such as Figure 1 As shown, the reasons for the failure of the side voltage test include voltage jumps or open circuits caused by poor contact of the soft-pack lithium battery under test; the control unit 160 is specifically used to determine the poor contact of the soft-pack lithium battery under test according to the following steps: detecting that the initial measured terminal voltage value is lower than the corresponding standard voltage lower limit threshold; or, detecting that the measured terminal voltage values ​​collected at least two previous time points are within the corresponding standard voltage threshold range, and the measured terminal voltage values ​​collected at subsequent time points jump to close to the initial measured terminal voltage value or drop to 0 volts, disrupting the overall degradation trend.

[0047] In its specific implementation, this application embodiment, in addition to identifying lithium battery body abnormalities (such as edge lithium plating or packaging defects) leading to unqualified edge voltage tests, specifically adds an intelligent discrimination mechanism for poor contact. Specifically, the control unit 160 identifies this through dual timing characteristics: Method 1: The initial measured terminal voltage value is lower than the corresponding standard voltage lower limit threshold (e.g., V0 < 45V), indicating that the circuit was not reliably connected at power-on; Method 2: The voltage at least two preceding time points is within their respective standard threshold ranges (e.g., V0 and V1 are qualified), but at a subsequent point (e.g., V2), it suddenly jumps to near the initial measured terminal voltage value or drops to 0 volts, disrupting the normal decay trend, reflecting a momentary open circuit-reconnection during testing. This mechanism can proactively trigger a retest or directly determine unqualified, avoiding accidental release.

[0048] Here, the multi-point timing determination mechanism proposed in this application upgrades the "poor contact detection" from a passive guarantee relying on hardware stability to an active algorithm identification based on voltage evolution law: when poor probe contact (such as oxidation, incomplete pressing, or cable micro-breakage) causes the test circuit to be in a high-resistance "empty test" state, the acquired terminal voltage sequence will show abnormal jumps or deviate from the standard threshold range as a whole; through bilateral control of independently set upper and lower limits at each time point, such missed samples can be forcibly identified and eliminated. The segmented threshold design accurately matches the physical characteristics of the side voltage decay over time. Even if the initial voltage V0 is in the qualified range, if a subsequent point (such as V2) exceeds the limit due to abnormal decay, it can still be effectively captured. This mechanism is specifically tailored for the technical feature of "ion-conducting side voltage". Examples: (1) V0=38V<45V (lower limit), directly judged as poor contact; (2) V0=48V and V1=47.5V are both qualified, but V2 suddenly rises to ≈39V (approximately V0) or drops to 0V, which disrupts the normal decay trend, and is judged as instantaneous open circuit-reconnection during the test, which is a poor contact.

[0049] In comparison, existing single-point wide thresholding methods (such as...) The 1V~1V test lacks a timing dimension, which can easily lead to the misinterpretation of "no-load test" as qualified, posing a serious quality hazard. Its essence is a static "one-size-fits-all" approach, which does not reflect the inherent dynamic attenuation mechanism of the side voltage.

[0050] In one possible implementation, such as Figure 1 As shown, the control unit 160 is further configured to determine the standard voltage threshold range corresponding to each time point according to the following steps: collecting the measured terminal voltage values ​​of multiple qualified soft-pack lithium batteries at the same preset time point; for each time point, based on the collected multiple measured terminal voltage values, calculating the upper limit threshold and lower limit threshold of the standard voltage corresponding to the time point using a preset statistical method.

[0051] In specific implementation, the embodiments of this application dynamically construct the standard voltage threshold range for each collection time point through empirical statistical methods: during the batch trial production stage, a large number of verified qualified soft-pack lithium batteries are collected, and their measured terminal voltage values ​​are collected synchronously at the same set of preset time points (such as t0, t1...tn); for all sample data at each time point, preset statistical methods such as box plots or the three-times standard deviation method are used to calculate the upper / lower limits of their distribution, thereby determining the upper and lower limits of the standard voltage corresponding to that time point.

[0052] Here, the standard voltage threshold range is determined based on the measured terminal voltage value after superimposing the analog voltage value of the analog module voltage source 140. For example, when the analog voltage value Vs of the analog module voltage source 140 is 5V, the threshold range of the measured side voltage value is [ When the voltage is 0.1V, the standard voltage threshold range corresponding to the measured terminal voltage value is set to [4.9V, 5.1V], which retains the physical meaning and significantly widens the measurable window. The standard voltage threshold range corresponding to each time point is set independently to accurately adapt to the voltage time series evolution characteristics.

[0053] For example, five time points were collected. During the positive terminal voltage test, the standard voltage threshold range of the measured terminal voltage V0 at time point t0 was, for example, 45V~51V; the standard voltage threshold range of the measured terminal voltage V1 at time point t1 was, for example, 10V~25V; the standard voltage threshold range of the measured terminal voltage V2 at time point t2 was, for example, 1V~10V; the standard voltage threshold range of the measured terminal voltage V3 at time point t3 was, for example, 0.2V~5V; and the standard voltage threshold range of the measured terminal voltage V4 at time point t4 was, for example, 0V~5V. During the negative terminal voltage test, the standard voltage threshold range for the measured terminal voltage V0 at time t0 is, for example, -51V to -45V; the standard voltage threshold range for the measured terminal voltage V1 at time t1 is, for example, -25V to -10V; the standard voltage threshold range for the measured terminal voltage V2 at time t2 is, for example, -10V to -1V; the standard voltage threshold range for the measured terminal voltage V3 at time t3 is, for example, -5V to -0.2V; and the standard voltage threshold range for the measured terminal voltage V4 at time t4 is, for example, -5V to 0V.

[0054] Based on the same application concept, this application also provides a method for testing the side voltage of a soft-pack lithium battery corresponding to the side voltage testing device for the soft-pack lithium battery provided in the above embodiments. Since the principle of solving the problem by the method in this application is similar to that of the side voltage testing device for the soft-pack lithium battery in the above embodiments of this application, the implementation of the method can refer to the implementation of the device, and the repeated parts will not be described again.

[0055] Figure 2 This is a flowchart illustrating a side voltage testing method for a pouch lithium battery provided in an embodiment of this application. Figure 2 As shown in the embodiments of this application, the side voltage testing method for soft-pack lithium batteries is applied to, for example... Figure 1 The method of the aforementioned soft-pack lithium battery side voltage testing device includes: S201: Place the soft-pack lithium battery under test on the support platform of the soft-pack lithium battery side voltage testing device, so that the positive electrode tab, negative electrode tab and aluminum-plastic film side sealing area of ​​the soft-pack lithium battery under test are exposed to the working area of ​​the corresponding probe.

[0056] S202: Control the first voltage probe to form a stable electrical contact with the surface of the positive electrode tab, control the second voltage probe to form a stable electrical contact with the surface of the negative electrode tab, and control the piercing probe to contact the aluminum layer of the aluminum-plastic film side seal.

[0057] S203: In response to the probe contact status signal, start multi-time point acquisition of the measured terminal voltage value.

[0058] S204: Compare the measured terminal voltage values ​​collected at each time point with the corresponding standard voltage threshold range, and output the side voltage test judgment result of the soft-pack lithium battery under test.

[0059] In the specific implementation, the pouch lithium battery is placed on the test device's support platform, aligning the positive electrode tab, negative electrode tab, and aluminum-plastic film side sealing area of ​​the pouch lithium battery with the corresponding probes. Then, three probes (a first voltage probe or a second voltage probe, and a puncture probe) are controlled to form stable electrical contacts with the positive electrode, negative electrode, and aluminum layer, respectively. After detecting the probe contact status signal, continuous acquisition of measured terminal voltage values ​​at multiple time points is initiated. Finally, the measured terminal voltage values ​​at each acquisition time are compared with preset corresponding standard threshold ranges, and the result of whether the side voltage test is qualified or unqualified is output. Thus, this embodiment of the application, through multi-point voltage acquisition and comparison with standard voltage threshold ranges, achieves coordinated verification of contact stability and dynamic characteristics of side voltage without relying on single-point instantaneous values, improving the reliability of test results and the ability to identify anomalies, and effectively avoiding missed or false judgments caused by poor contact or weak ion conduction.

[0060] Here, considering that the micro-short circuit caused by ion conduction will cause the side voltage to exhibit a "rapid decay" characteristic, this embodiment of the application can completely record the voltage decay curve by collecting voltage values ​​at multiple consecutive time points. Even if the initial measured terminal voltage value is within the corresponding standard voltage threshold range, if the subsequent voltage exceeds the standard due to excessive decay, it can be accurately identified, thereby precisely eliminating batteries with ion conduction risk.

[0061] Furthermore, in real-world applications, multiple pouch lithium batteries are often connected in series to form battery modules. When the total voltage of the battery module is high (e.g., several hundred volts), minute voltage anomalies in a single cell (a single pouch lithium battery) (such as millivolt-level ion conduction leakage) can be amplified by the high-voltage environment of the battery module, making it easier to cause safety accidents. However, during single-cell testing, such millivolt-level anomaly signals are very weak and easily masked by the noise floor, temperature drift, or AD acquisition accuracy of the testing equipment itself.

[0062] Here, in this embodiment of the application, a simulated module voltage source proportional to the actual battery module voltage is connected in series in the test circuit. This elevates the weak side voltage signal, which originally fluctuated around zero, to a voltage range much higher than the system noise. This ensures that even an abnormal shift of only a few millivolts in the measured side voltage value will be reflected in the measured terminal voltage value by the same magnitude. Furthermore, because the simulated voltage value is much larger than the noise, the resolution and sensitivity of the measurement system to this shift are improved by orders of magnitude.

[0063] It is understood that the embodiments of this application simulate the electrical stress state of the battery cell under the actual high-voltage environment of the module, achieving "consistency between test conditions and application conditions". Compared with traditional direct measurement methods, this application can detect potential ion conduction paths and corrosion risks earlier and more sensitively, and accurately eliminate hidden dangers that may only be exposed in the module at the battery cell stage.

[0064] For example, during a month of continuous battery production (1,296,402 cells), the second sealing stage identified 13 defective cells that had been missed during formation and returned them for rework, avoiding the scrapping of 13 cells compared to the original solution. The second sealing stage also identified 7 cells with welding abnormalities due to internal resistance issues, which were reported to the front-end for confirmation and improvement, reducing the anomaly identification cycle by approximately 2 days compared to the original solution. No batch anomalies occurred during the production period.

[0065] In one possible implementation, Figure 3 This is a flowchart illustrating another method for testing the side voltage of a pouch lithium battery, as provided in an embodiment of this application. Figure 3 As shown in the embodiments of this application, the side voltage testing method for soft-pack lithium batteries is applied to, for example... Figure 1 The method of the aforementioned soft-pack lithium battery side voltage testing device includes: S301: Place the soft-pack lithium battery under test on the support platform of the soft-pack lithium battery side voltage testing device, so that the positive electrode tab, negative electrode tab and aluminum-plastic film side sealing area of ​​the soft-pack lithium battery under test are exposed to the working area of ​​the corresponding probe.

[0066] S302: When performing a positive electrode edge voltage test, the piercing probe is driven to press down and pierce the aluminum-plastic film to form an electrical contact with the aluminum layer. At the same time, the first voltage probe is driven to press down and contact the positive electrode tab of the soft-pack lithium battery under test.

[0067] S303: In response to the probe contact status signal, start multi-time point acquisition of the measured terminal voltage value.

[0068] S304: Compare the measured terminal voltage values ​​collected at each time point with the corresponding standard voltage threshold range, and output the side voltage test judgment result of the soft-pack lithium battery under test.

[0069] In one possible implementation, the method further includes: when performing a negative electrode edge voltage test, driving the piercing probe to press down and pierce the aluminum-plastic film and form electrical contact with the aluminum layer, while simultaneously driving the second voltage probe to press down and contact the negative electrode tab of the soft-pack lithium battery under test.

[0070] In one possible implementation, the method further includes collecting the measured terminal voltage value according to the following steps: after the first voltage probe or the second voltage probe is pressed down and triggers a contact signal, the initial measured terminal voltage value is collected after a first preset time delay.

[0071] In one possible implementation, the method further includes, after acquiring the initial measured terminal voltage value, acquiring a subsequent preset number of measured terminal voltage values ​​sequentially at a fixed second preset time interval.

[0072] In practical implementation, by introducing a fixed delay (first preset time) and a fixed interval (second preset time), the testing process is transformed from "single-point random sampling" to "standardized time series sampling". Regardless of the PLC response speed of the equipment, the starting point and interval of the collected voltage sequence remain consistent, so that the test results are no longer affected by equipment differences and time drift, which greatly improves the consistency and comparability of test data among multiple devices on the production line.

[0073] In one possible implementation, the method further includes determining whether the side voltage test of the pouch lithium battery under test is qualified according to the following steps: for each time point, comparing the measured side voltage value collected at the time point with the standard voltage threshold range corresponding to the time point; if the measured side voltage value collected at any time point exceeds the corresponding standard voltage threshold range, then the side voltage test of the pouch lithium battery under test is determined to be unqualified; if the measured side voltage values ​​collected at all the time points are within their respective standard voltage threshold ranges, then the side voltage test of the pouch lithium battery under test is determined to be qualified.

[0074] In one possible implementation, the method further includes determining the poor contact of the pouch lithium battery under test according to the following steps: detecting that the initial measured terminal voltage value is lower than the corresponding standard voltage lower limit threshold; or, detecting that the measured terminal voltage values ​​collected at least two previous time points are within the corresponding standard voltage threshold range, and the measured terminal voltage values ​​collected at subsequent time points jump to close to the initial measured terminal voltage value or drop to 0 volts, disrupting the overall degradation trend.

[0075] In its implementation, this application employs a multi-point judgment mechanism, imposing higher requirements on the contact state. If the probe and the tab have poor contact (such as a loose connection or oxidation), the acquired voltage sequence will exhibit large fluctuations, irregular jumps, or a completely open circuit. Since this application requires that the measured terminal voltage value acquired at each time point must simultaneously meet the standard, such an unstable contact state is almost impossible to pass the judgment of all acquisition points. This forcibly filters out abnormal batteries caused by contact problems, avoiding the serious quality risk of "over-testing without testing" in traditional single-point testing.

[0076] In one possible implementation, the method further includes determining the standard voltage threshold range corresponding to each time point according to the following steps: collecting the measured terminal voltage values ​​of multiple qualified soft-pack lithium batteries at the same set of preset time points; for each time point, based on the collected multiple measured terminal voltage values, calculating the upper limit threshold and the lower limit threshold of the standard voltage corresponding to the time point using a preset statistical method.

[0077] Based on the same application concept, see [link / reference] Figure 4 The diagram shown is a structural schematic of an electronic device 400 provided in an embodiment of this application. It includes a processor 410, a memory 420, and a bus 430. The memory 420 stores machine-readable instructions executable by the processor 410. When the electronic device 400 is running, the processor 410 and the memory 420 communicate through the bus 430. When the machine-readable instructions are executed by the processor 410, they perform the steps of the side voltage testing method for a soft-pack lithium battery as described in any of the above embodiments.

[0078] Specifically, when the machine-readable instructions are executed by the processor 410, the following processing can be performed: The soft-pack lithium battery under test is placed on the support platform of the soft-pack lithium battery side voltage testing device, so that the positive electrode tab, negative electrode tab and aluminum-plastic film side sealing area of ​​the soft-pack lithium battery under test are exposed to the action area of ​​the corresponding probe respectively. The first voltage probe is controlled to form a stable electrical contact with the surface of the positive electrode tab, the second voltage probe is controlled to form a stable electrical contact with the surface of the negative electrode tab, and the piercing probe is controlled to contact the aluminum layer of the aluminum-plastic film side seal. In response to the probe contact status signal, the measured terminal voltage value is acquired at multiple time points. The measured terminal voltage values ​​collected at each time point are compared with the corresponding standard voltage threshold range, and the side voltage test judgment result of the soft-pack lithium battery under test is output.

[0079] Based on the same concept, this application also provides a computer-readable storage medium storing a computer program, which, when run by a processor, executes the steps of the side voltage testing method for a soft-pack lithium battery provided in the above embodiments.

[0080] Specifically, the storage medium can be a general-purpose storage medium, such as a portable disk or hard disk. When the computer program on the storage medium is run, it can execute the above-mentioned side voltage test method for soft-pack lithium batteries. By collecting the measured side voltage values ​​at multiple time points and connecting the analog module voltage source in series in the test circuit, the accuracy and stability of the test results can be improved.

[0081] In this embodiment, the computer program, when run by the processor, can also execute other machine-readable instructions to perform other methods as described in the embodiments. For details on the specific execution steps and principles, please refer to the description of the embodiments, which will not be repeated here.

[0082] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0083] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0084] In addition, the functional units in the embodiments provided in this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0085] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0086] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0087] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application. All should be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A device for testing the side voltage of a soft-pack lithium battery, characterized in that, The device includes a puncture probe, a first voltage probe, a second voltage probe, an analog module voltage source, a data acquisition unit, and a control unit; The piercing probe is used to pierce the aluminum-plastic film of the soft-pack lithium battery under test, making contact with the aluminum layer of the aluminum-plastic film; the first voltage probe is used to contact the positive electrode tab of the soft-pack lithium battery under test during positive electrode side voltage testing; the second voltage probe is used to contact the negative electrode tab of the soft-pack lithium battery under test during negative electrode side voltage testing; the analog module voltage source is connected in series in the test circuit, and the test circuit is the circuit between the piercing probe and the first voltage probe or the second voltage probe; the data acquisition unit is electrically connected to the piercing probe, the first voltage probe, the second voltage probe, and the analog module voltage source; the control unit is connected to the data acquisition unit and the driving mechanism of each probe. The control unit is used to control the corresponding probe action according to the side voltage test type, and to continuously collect the measured side voltage value at multiple time points to determine whether the side voltage state of the soft-pack lithium battery under test is normal.

2. The apparatus according to claim 1, characterized in that, When performing a positive electrode voltage test, the positive terminal of the simulated module voltage source is connected to the positive electrode tab of the soft-pack lithium battery under test, and the negative terminal of the simulated module voltage source is connected to the puncture probe. The control unit is specifically used to drive the piercing probe to press down and pierce the aluminum-plastic film and form electrical contact with the aluminum layer, and at the same time, drive the first voltage probe to press down and contact the positive electrode tab of the soft-pack lithium battery under test.

3. The apparatus according to claim 1, characterized in that, When performing a negative electrode voltage test, the positive terminal of the simulated module voltage source is connected to the piercing probe, and the negative terminal of the simulated module voltage source is connected to the negative electrode tab of the soft-pack lithium battery under test. The control unit is specifically used to drive the piercing probe to press down and pierce the aluminum-plastic film and form electrical contact with the aluminum layer, while simultaneously driving the second voltage probe to press down and contact the negative electrode tab of the soft-pack lithium battery under test.

4. The apparatus according to claim 1, characterized in that, The measured terminal voltage value collected at any time point is the sum of the actual side voltage of the soft-pack lithium battery under test and the simulated voltage value of the simulated module voltage source; wherein, the simulated voltage value is set according to the total voltage of the battery module formed by multiple soft-pack lithium batteries under test connected in series in the actual application scenario, or the working voltage corresponding to a single soft-pack lithium battery under test.

5. The apparatus according to claim 1, characterized in that, The control unit is specifically used to collect the measured terminal voltage value according to the following steps: After the first voltage probe or the second voltage probe is pressed down and triggers the contact signal, the initial measured terminal voltage value is collected after a first preset time delay.

6. The apparatus according to claim 5, characterized in that, The control unit is also used for: After acquiring the initial measured terminal voltage value, a subsequent preset number of measured terminal voltage values ​​are acquired sequentially at a fixed second preset time interval.

7. The apparatus according to claim 1, characterized in that, The control unit is also used to determine whether the side voltage test of the soft-pack lithium battery under test is qualified according to the following steps: For each time point, the measured terminal voltage value collected at that time point is compared with the standard voltage threshold range corresponding to that time point; If the measured terminal voltage value collected at any of the aforementioned time points exceeds the corresponding standard voltage threshold range, then the side voltage test of the soft-pack lithium battery under test is deemed unqualified. If the measured terminal voltage values ​​collected at all the time points are within their respective standard voltage threshold ranges, then the side voltage test of the soft-pack lithium battery under test is deemed to be qualified.

8. The apparatus according to claim 1, characterized in that, The reasons for the failure of the side voltage test include voltage jumps or open circuits caused by poor contact of the soft-pack lithium battery under test; the control unit is specifically used to determine the poor contact of the soft-pack lithium battery under test according to the following steps: The initial measured terminal voltage value was detected to be lower than the corresponding standard voltage lower limit threshold; or, The system detects that the measured terminal voltage values ​​collected at least two prior time points are within the corresponding standard voltage threshold range, and that the measured terminal voltage values ​​collected at subsequent time points jump to near the initial measured terminal voltage value or drop to 0 volts, thus disrupting the overall attenuation trend.

9. The apparatus according to claim 7, characterized in that, The control unit is further configured to determine the standard voltage threshold range corresponding to each time point according to the following steps: Collect the measured terminal voltage values ​​of multiple qualified soft-pack lithium batteries at the same preset time point; For each time point, based on the collected multiple measured terminal voltage values, a preset statistical method is used to calculate the corresponding standard voltage upper limit threshold and standard voltage lower limit threshold.

10. A method for testing the side voltage of a soft-pack lithium battery, characterized in that, The device for testing the side voltage of a pouch lithium battery according to any one of claims 1-9; the method includes: The soft-pack lithium battery to be tested is placed on the support platform of the soft-pack lithium battery side voltage testing device, so that the positive electrode tab, negative electrode tab and aluminum-plastic film side sealing area of ​​the soft-pack lithium battery to be tested are respectively exposed to the action area of ​​the corresponding probe. The first voltage probe is controlled to form a stable electrical contact with the surface of the positive electrode tab, the second voltage probe is controlled to form a stable electrical contact with the surface of the negative electrode tab, and the piercing probe is controlled to contact the aluminum layer of the aluminum-plastic film side seal. In response to the probe contact status signal, the measured terminal voltage value is acquired at multiple time points. The measured terminal voltage values ​​collected at each time point are compared with the corresponding standard voltage threshold range, and the side voltage test judgment result of the soft-pack lithium battery under test is output.

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