Battery anomaly detection method and device and electronic equipment

Abstract

The invention discloses a battery anomaly detection method and device and electronic equipment. The method relates to the technical field of batteries, and comprises the following steps: in response to a received electrolyte injection instruction, controlling to inject an electrolyte into a to-be-detected battery, so that the electrolyte infiltrates a pole piece of the to-be-detected battery; acquiring a voltage change curve of the to-be-tested battery in the infiltration process; and based on the voltage change curve, determining an anomaly detection result of the to-be-detected battery, the anomaly detection result being at least used for indicating whether self-discharge anomaly exists in the to-be-detected battery. According to the invention, the technical problem of low detection efficiency of battery self-discharge anomaly detection after battery manufacturing in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery abnormality detection method, device and electronic equipment. Background Art

[0002] Lithium-ion batteries have been widely used in energy storage, mobile devices, electric vehicles, aerospace and other fields due to their high energy density, long cycle life, high coulombic efficiency and wide operating temperature range. In the manufacturing process of lithium-ion batteries, due to the wear of equipment and pipelines, metal impurities may be mixed into the electrode materials, forming micro short circuits and causing battery self-discharge. In most cases, lithium-ion batteries are used in the form of battery packs connected in series or parallel, and the inconsistency of self-discharge at this time will greatly affect the life and safety of the battery pack.

[0003] A battery self-discharge screening method is disclosed in the related art, including: charging a group of batteries and then placing them at rest and measuring their first voltage; placing the batteries at rest for a second time and measuring their second voltage after completion; calculating the K value of the batteries, and judging whether the batteries are qualified based on whether the actual K value of the batteries is less than a preset reference value. However, this method cannot screen out batteries with abnormal self-discharge in the early stage of battery manufacturing, and requires a certain measurement cycle, which increases the waste of resources and time.

[0004] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0005] The embodiments of the present invention provide a battery abnormality detection method, device and electronic device to at least solve the technical problem of low detection efficiency in performing battery self-discharge abnormality detection after battery manufacturing in the related art.

[0006] According to one aspect of an embodiment of the present invention, a battery abnormality detection method is provided, comprising: in response to receiving an electrolyte injection instruction, controlling the injection of electrolyte into a battery to be tested so that the electrolyte infiltrates a pole piece of the battery to be tested; obtaining a voltage change curve of the battery to be tested during the infiltration process; based on the voltage change curve, determining an abnormality detection result of the battery to be tested, wherein the abnormality detection result is at least used to indicate whether the battery to be tested has a self-discharge abnormality.

[0007] The voltage change curve can reflect the change of the voltage fluctuation of the battery under test over time. Through this voltage change curve, the voltage change characteristics of the battery under test can be reflected. By analyzing the voltage change curve, the battery self-discharge abnormality detection can be realized during the battery manufacturing process, and the battery self-discharge detection efficiency can be improved.

[0008] Optionally, the controlling of injecting electrolyte into the battery to be tested so that the electrolyte infiltrates the pole piece of the battery to be tested comprises: after controlling the injecting of electrolyte into the battery to be tested, controlling the battery to be tested to be placed in a high temperature environment for static treatment so that the electrolyte infiltrates the pole piece of the battery to be tested.

[0009] After the electrolyte is injected into the battery to be tested, the battery to be tested is placed in a high-temperature environment and left to stand for a predetermined period of time. The high-temperature heating can accelerate the process of the electrolyte infiltrating the electrode of the battery to be tested.

[0010] Optionally, acquiring the voltage change curve of the battery to be tested during the infiltration process includes: acquiring the temperature in the high-temperature environment; and acquiring the voltage change curve of the battery to be tested during the infiltration process when the temperature is greater than a preset temperature threshold.

[0011] By monitoring the temperature in a high-temperature environment in real time, the voltage of the battery to be tested is monitored and recorded only when the temperature is greater than the preset temperature threshold. The voltage change curve obtained on this basis can truly reflect the voltage change characteristics of the battery to be tested, which helps to accurately identify abnormalities in the battery to be tested.

[0012] Optionally, obtaining the voltage change curve of the battery to be tested during the infiltration process includes: obtaining the infiltration voltages of the battery to be tested corresponding to multiple sampling moments during the infiltration process; constructing an initial voltage curve based on the infiltration voltages corresponding to the multiple sampling moments; and smoothing the initial voltage curve to obtain the voltage change curve.

[0013] By smoothing the initial voltage curve, the tiny voltage fluctuations caused by the temperature fluctuations of the high temperature environment can be filtered out, and the influence of the temperature fluctuations of the high temperature environment on the accuracy of the infiltration voltage acquisition can be eliminated. The voltage change curve thus obtained can more truly reflect the voltage change characteristics caused by the operation of the battery under test itself.

[0014] Optionally, during the infiltration process, the infiltration voltages corresponding to the battery to be tested at multiple sampling moments are obtained, including: during the infiltration process, the infiltration voltage of the battery to be tested at any sampling moment among the multiple sampling moments is obtained in the following manner: obtaining the first potential of the positive electrode of the battery to be tested in the electrolyte at any sampling moment, and the second potential of the battery to be tested in the electrolyte; calculating the potential difference between the first potential and the second potential; using the potential difference as the infiltration voltage at any sampling moment; and obtaining the infiltration voltages corresponding to the multiple sampling moments in the manner of obtaining the infiltration voltage at any sampling moment.

[0015] By measuring the potential of the electrode in the electrolyte, we can understand the potential difference between the positive and negative electrodes of the battery, reflecting the chemical reaction and voltage changes inside the battery. The potential difference can reflect the reaction activity and potential changes inside the battery, which helps to evaluate the performance and health of the battery. Using the potential difference as the infiltration voltage can be used to monitor the performance changes, status and health of the battery. The voltage change curve obtained on this basis can more realistically reflect the voltage change characteristics caused by the operation of the battery itself.

[0016] Optionally, determining the abnormal detection result of the battery to be tested based on the voltage change curve includes: determining the peak voltage in the voltage change curve, and the end voltage at the end of the infiltration process; determining the voltage difference between the peak voltage and the end voltage; and determining the abnormal detection result of the battery to be tested based on the voltage difference.

[0017] By determining the peak voltage and the end voltage, we can understand the voltage change of the battery during the discharge process and evaluate the discharge performance of the battery. By calculating the voltage difference, we can quantify the voltage change of the battery during the discharge process and determine whether the battery has abnormal self-discharge. According to the size of the voltage difference, we can determine whether the battery has abnormal self-discharge and promptly detect whether there is a self-discharge problem in the battery.

[0018] Optionally, determining the abnormal detection result of the battery to be tested based on the voltage difference includes: judging whether the voltage difference is greater than a preset difference threshold; when the voltage difference is greater than the preset difference threshold, determining the abnormal detection result as: the battery to be tested has a self-discharge abnormality; when the voltage difference is less than or equal to the preset difference threshold, determining the abnormal detection result as: the battery to be tested does not have a self-discharge abnormality.

[0019] By judging the voltage difference by threshold, it is possible to quickly identify whether the battery under test has self-discharge anomalies, with high detection efficiency.

[0020] Optionally, the self-discharge includes self-discharge caused by one or more factors including dust, burrs, positive electrode metal foreign matter and negative electrode metal foreign matter; and the voltage difference is proportional to the degree of the self-discharge.

[0021] By analyzing the self-discharge caused by factors such as dust, burrs, positive metal foreign matter and negative metal foreign matter, it can help determine the specific cause of battery self-discharge; since the voltage difference is proportional to the degree of self-discharge, the self-discharge of the battery can be evaluated and monitored by monitoring the changes in the voltage difference, and battery problems can be discovered in time.

[0022] According to another aspect of an embodiment of the present invention, a battery abnormality detection device is also provided, including: an electrolyte injection control module, which is used to control the injection of electrolyte into a battery to be tested in response to receiving an electrolyte injection instruction, so that the electrolyte infiltrates the electrode of the battery to be tested; a voltage change curve acquisition module, which is used to obtain the voltage change curve of the battery to be tested during the infiltration process; and a detection result determination module, which is used to determine the abnormality detection result of the battery to be tested based on the voltage change curve, wherein the abnormality detection result is at least used to indicate whether the battery to be tested has a self-discharge abnormality.

[0023] According to another aspect of an embodiment of the present invention, there is also provided an electronic device, comprising one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement any one of the battery abnormality detection methods.

[0024] In an embodiment of the present invention, in response to receiving an electrolyte injection instruction, the electrolyte is controlled to be injected into the battery to be tested so that the electrolyte infiltrates the electrode of the battery to be tested; the voltage change curve of the battery to be tested during the infiltration process is obtained; based on the voltage change curve, the abnormal detection result of the battery to be tested is determined, wherein the abnormal detection result is at least used to indicate whether the battery to be tested has a self-discharge abnormality, thereby achieving the purpose of collecting the voltage change curve and analyzing the voltage in the electrolyte infiltration link in the battery manufacturing process to determine whether the battery to be tested has an abnormality, thereby achieving the technical effect of performing battery self-discharge abnormality detection in the battery manufacturing process and improving the battery self-discharge detection efficiency, thereby solving the technical problem of low detection efficiency in the related art of performing battery self-discharge abnormality detection after the battery is manufactured. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 is a flow chart of a battery abnormality detection method according to an embodiment of the present invention;

[0027] Figure 2 is a flow chart of an optional battery abnormality detection method according to an embodiment of the present invention;

[0028] Figure 3 is a schematic diagram of an optional wetting voltage detection result according to an embodiment of the present invention;

[0029] Figure 4is a schematic diagram of an optional battery abnormality detection system structure according to an embodiment of the present invention;

[0030] Figure 5 is a schematic diagram of a battery abnormality detection device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] During the manufacturing process of lithium-ion batteries, due to the wear of equipment and pipelines, metal impurities may be mixed into the electrode materials, forming micro short circuits and causing battery self-discharge. In most cases, lithium-ion batteries are used in the form of battery packs connected in series or parallel, and the inconsistency of self-discharge at this time will greatly affect the life and safety of the battery pack. Usually, self-discharge screening is performed after the battery is manufactured and charged, and a certain measurement cycle is required. However, the above detection methods are inefficient and increase the waste of resources and time.

[0034] Based on this, an embodiment of the present invention provides a method embodiment for detecting battery abnormality. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0035] Figure 1 is a flow chart of a battery abnormality detection method according to an embodiment of the present invention. Figure 1As shown, the method comprises the following steps:

[0036] Step S102, in response to receiving the electrolyte injection instruction, controlling the electrolyte to be injected into the battery to be tested, so that the electrolyte infiltrates the electrode of the battery to be tested;

[0037] Optionally, the battery to be tested is one or more assembled batteries, such as one or more assembled lithium-ion batteries. Anomaly detection can be performed on a batch of assembled batteries at the same time. In the process of battery manufacturing, the link after the battery assembly is completed is the electrolyte infiltration link, in which the electrolyte is injected into the battery to be tested so that the electrolyte infiltrates the electrode of the battery to be tested, wherein the electrode includes a positive electrode and a negative electrode.

[0038] Optionally, the assembly includes assembling the positive electrode sheet and the negative electrode sheet into an electrode group, welding and sealing the electrode group in a shell, and baking and drying to obtain an assembled battery. The positive electrode sheet and the negative electrode sheet are obtained by coating the positive electrode slurry and the negative electrode slurry on the surface of the positive electrode and the negative electrode current collector, and drying.

[0039] Optionally, the positive electrode active material in the positive electrode slurry is one or more of lithium iron phosphate, lithium manganese oxide, lithium cobalt oxide, and ternary materials, the negative electrode active material in the negative electrode slurry is one or more of graphite, lithium titanate, silicon oxide, silicon carbon and hard carbon, the positive electrode collector is aluminum foil, and the negative electrode collector is copper foil.

[0040] Optionally, the electrode sheet is laminated or wound, a separator is provided between the positive electrode sheet and the negative electrode sheet, and the separator is a dry-process polypropylene (PP) separator, a wet-process polyethylene (PE) separator, a ceramic separator or a rubber-coated separator. The shell is an aluminum shell or a soft package.

[0041] Optionally, the baking method is air-flow type or contact type. Among them, air-flow baking is to heat the air and then circulate the hot air inside the oven to conduct heat to evenly heat the items. In the battery manufacturing process, air-flow baking is often used to quickly and evenly heat battery components or parts to achieve a specific heat treatment effect. Contact baking is to heat the items by conducting heat through direct contact between the items and the heat source. In the battery manufacturing process, contact baking is often used to locally heat specific areas or parts to achieve precise temperature control and heat treatment effects.

[0042] In an optional embodiment, controlling the injection of electrolyte into the battery to be tested so that the electrolyte infiltrates the electrode of the battery to be tested includes: after controlling the injection of electrolyte into the battery to be tested, controlling the battery to be tested to be placed in a high temperature environment for static treatment so that the electrolyte infiltrates the electrode of the battery to be tested.

[0043] Optionally, after the electrolyte is injected into the battery to be tested, the battery to be tested is placed in a high temperature environment and left to stand for a predetermined period of time. The high temperature heating can accelerate the process of the electrolyte infiltrating the electrode of the battery to be tested. The high temperature environment can be, but is not limited to, a high temperature warehouse, which can be a warehouse for heating the battery to be tested, and the temperature in the high temperature warehouse can be greater than 42°C. The predetermined period of time can be, but is not limited to, a period of time greater than 48 hours.

[0044] Optionally, the static treatment may be a high-temperature static treatment, which is a process of placing the battery in a high-temperature reservoir to allow the electrolyte to infiltrate the electrodes and the separator.

[0045] Step S104, obtaining a voltage variation curve of the battery to be tested during the soaking process;

[0046] Optionally, the voltage change curve is used to indicate the relationship between the wetting voltage and time of the voltage to be tested. That is, the voltage change curve is constructed based on multiple sampling moments during the wetting process of the battery to be tested, and the wetting voltages collected at multiple sampling moments. Through the voltage change curve, the voltage fluctuation of the battery to be tested during the wetting process can be reflected. In the above manner, it is possible to collect the voltage change curve during the manufacturing process of the battery to be tested (specifically the wetting process) for subsequent abnormality detection of the battery to be tested, thereby screening out batteries with abnormal self-discharge during the battery manufacturing stage, saving the resources and time required for battery abnormality detection.

[0047] In an optional embodiment, obtaining a voltage change curve of the battery to be tested during the soaking process includes: collecting the temperature in a high temperature environment; and when the temperature is greater than a preset temperature threshold, collecting the voltage change curve of the battery to be tested during the soaking process.

[0048] Optionally, the time for voltage monitoring and recording of the battery to be tested may be the time for the battery to be tested to be immersed in high temperature, that is, the time when the temperature in the high temperature environment (such as a high temperature storage) is greater than a preset temperature threshold (such as 42°C), and the collection duration may be greater than a predetermined duration (such as 48 hours).

[0049] It should be noted that in a low temperature environment, the activity of some foreign matter is low, resulting in little effect on the voltage change of the battery under test. By real-time monitoring of the temperature in a high temperature environment, the voltage of the battery under test is monitored and recorded only when the temperature is greater than the preset temperature threshold. The voltage change curve obtained on this basis can truly reflect the voltage change characteristics of the battery under test, which helps to accurately identify abnormalities in the battery under test.

[0050] Optionally, the voltage variation curve may be determined by using, but not limited to, a smooth curve method, wherein the smooth curve method may be any one of a sliding average filter, an exponential sliding average filter, a Savitzky-Golay filter, and the like.

[0051] In an optional embodiment, a voltage change curve of the battery to be tested during the infiltration process is obtained, including: during the infiltration process, obtaining the infiltration voltages of the battery to be tested corresponding to multiple sampling moments respectively; constructing an initial voltage curve based on the infiltration voltages corresponding to the multiple sampling moments respectively; and smoothing the initial voltage curve to obtain a voltage change curve.

[0052] It should be noted that since temperature fluctuations in a high-temperature environment (such as a high-temperature storage) may cause slight fluctuations in the wetting voltage of the battery to be tested, an initial voltage curve can be constructed based on the wetting voltages collected for the voltage to be tested at multiple sampling moments. By smoothing the initial voltage curve, slight voltage fluctuations caused by temperature fluctuations in the high-temperature environment can be filtered out, and the influence of temperature fluctuations in the high-temperature environment on the accuracy of wetting voltage collection can be eliminated. The voltage change curve thus obtained can more truly reflect the voltage change characteristics caused by the operation of the battery to be tested itself.

[0053] Optionally, the wetting voltage may be the difference between the potential of the positive electrode sheet of the battery to be tested in the electrolyte and the potential of the negative electrode sheet in the electrolyte, that is, the voltage between the positive and negative electrodes of the battery to be tested.

[0054] In an optional embodiment, during the infiltration process, the infiltration voltages corresponding to the battery to be tested at multiple sampling moments are obtained, including: during the infiltration process, the infiltration voltage of the battery to be tested at any sampling moment among the multiple sampling moments is obtained in the following manner: obtaining the first potential of the positive electrode of the battery to be tested in the electrolyte at any sampling moment, and the second potential of the battery to be tested in the electrolyte; calculating the potential difference between the first potential and the second potential; using the potential difference as the infiltration voltage at any sampling moment; and using the method of obtaining the infiltration voltage at any sampling moment to obtain the infiltration voltages corresponding to multiple sampling moments.

[0055] Optionally, the potential of the positive electrode and the negative electrode of the battery to be tested in the electrolyte are obtained by a potential measuring instrument to obtain a first potential and a second potential respectively; the potential difference between the first potential and the second potential is calculated to obtain the potential difference of the electrodes in the electrolyte; the potential difference is used as the wetting voltage at that moment to evaluate the performance and state of the battery. In the above method, by measuring the potential of the electrode in the electrolyte, the potential difference between the positive and negative electrodes of the battery can be understood, reflecting the chemical reaction and voltage changes inside the battery. The potential difference can reflect the reaction activity and potential changes inside the battery, which is helpful to evaluate the performance and health of the battery. Using the potential difference as the wetting voltage can be used to monitor the performance changes, state and health of the battery. The voltage change curve obtained on this basis can more truly reflect the voltage change characteristics caused by the operation of the battery to be tested itself.

[0056] Step S106, determining an abnormality detection result of the battery to be tested based on the voltage variation curve, wherein the abnormality detection result is at least used to indicate whether the battery to be tested has a self-discharge abnormality.

[0057] Optionally, the voltage change curve can reflect the change of the voltage fluctuation of the battery under test over time. Through the voltage change curve, the voltage change characteristics of the battery under test can be reflected. By analyzing the voltage change curve, the battery self-discharge abnormality detection can be realized during the battery manufacturing process, and the battery self-discharge detection efficiency can be improved.

[0058] In an optional embodiment, based on the voltage change curve, determining the abnormal detection result of the battery to be tested, including: determining the peak voltage in the voltage change curve, and the end voltage at the end of the infiltration process; determining the voltage difference between the peak voltage and the end voltage; based on the voltage difference, determining the abnormal detection result of the battery to be tested.

[0059] Optionally, in the discharge test, first observe the voltage change curve to determine the peak voltage and end voltage during the discharge process. The peak voltage is the highest value reached by the voltage during the discharge process, and the end voltage is the voltage value at the end of the discharge process. Calculate the voltage difference between the peak voltage and the end voltage, that is, the peak voltage minus the end voltage value to obtain the voltage difference. According to the voltage difference, determine whether the battery to be tested has self-discharge abnormality. Under normal circumstances, the self-discharge of the battery should be a slower process, and the voltage change should not be too large. If the voltage difference is large, it means that the battery has abnormal self-discharge during the discharge process, which may be caused by damage to the internal structure of the battery or other problems.

[0060] In the above method, by determining the peak voltage and the end voltage, the voltage change of the battery during the discharge process can be understood and the discharge performance of the battery can be evaluated. By calculating the voltage difference, the voltage change of the battery during the discharge process can be quantified to determine whether the battery has self-discharge anomalies. According to the size of the voltage difference, it can be determined whether the battery has abnormal self-discharge and whether there is a self-discharge problem in the battery. And because the voltage change curve is obtained in the battery manufacturing process, it is possible to detect abnormal self-discharge of the battery during the battery manufacturing process, thereby improving the efficiency of battery self-discharge detection.

[0061] Optionally, the peak voltage in the voltage change curve may be determined by one or more of the differential method and the dichotomy method, but is not limited to the differential method. When the peak voltage is determined by the differential method and the dichotomy method, the peak voltage required for the final voltage difference calculation may be obtained by weighted calculation of the peak voltages by the differential method and the dichotomy method.

[0062] In an optional embodiment, the self-discharge includes self-discharge caused by one or more factors of dust, burrs, positive metal foreign matter and negative metal foreign matter; the voltage difference is proportional to the degree of self-discharge. That is, the voltage difference between the peak voltage V1 of the battery infiltration and the voltage V2 at the end of infiltration is proportional to the size of the battery self-discharge. The greater the self-discharge, the greater the voltage difference between V1 and V2.

[0063] In the above methods, by analyzing the self-discharge caused by factors such as dust, burrs, positive metal foreign matter and negative metal foreign matter, it can help determine the specific cause of battery self-discharge; according to the proportional relationship between the voltage difference and the degree of self-discharge, the self-discharge of the battery can be evaluated and monitored by monitoring the change of the voltage difference, and the problems of the battery can be discovered in time. The size of the voltage difference can not only determine whether the battery under test has self-discharge anomalies, but also identify the degree of self-discharge of the battery under test.

[0064] Optionally, the positive electrode metal foreign matter and the negative electrode metal foreign matter include one or more metals such as iron, nickel, copper, zinc, and chromium.

[0065] In an optional embodiment, based on the voltage difference, the abnormal detection result of the battery to be tested is determined, including: judging whether the voltage difference is greater than a preset difference threshold; when the voltage difference is greater than the preset difference threshold, determining the abnormal detection result as: the battery to be tested has a self-discharge abnormality; when the voltage difference is less than or equal to the preset difference threshold, determining the abnormal detection result as: the battery to be tested does not have a self-discharge abnormality.

[0066] It can be understood that since the voltage difference is proportional to the degree of self-discharge, a preset difference threshold can be set as a criterion for determining whether the battery to be tested has self-discharge anomalies. When the voltage difference is greater than the preset difference threshold, it is determined that the battery to be tested has an anomaly; otherwise, it is determined that the battery to be tested has no anomaly. In the above manner, by performing a threshold judgment on the voltage difference, it is possible to quickly identify whether the battery to be tested has self-discharge anomalies, which has a high detection efficiency.

[0067] Optionally, when it is determined that the battery to be tested has an abnormality, the disposal method for the battery to be tested can be further determined based on the size of the voltage difference. When the voltage difference is greater than the first difference threshold, the disposal method for the battery to be tested is determined to be downshift processing; when the voltage difference is greater than the second difference threshold, the disposal method for the battery to be tested is determined to be rejection processing, wherein the second difference threshold is greater than the first difference threshold; downshift processing is used to indicate that the quality level of the battery to be tested is reduced, and the battery to be tested is filed into a batch with a lower quality level; rejection processing is used to indicate that the quality of the battery to be tested is unqualified, and the battery to be tested is rejected in the manufacturing process, and the subsequent manufacturing process of the battery to be tested is not continued.

[0068] Through the above steps S102 to S106, the purpose of collecting the voltage change curve and analyzing the voltage in the electrolyte infiltration link in the battery manufacturing process can be achieved to determine whether the battery to be tested has an abnormality, thereby realizing the technical effect of performing battery self-discharge abnormality detection in the battery manufacturing process and improving the battery self-discharge detection efficiency, thereby solving the technical problem of low detection efficiency in the related technology of performing battery self-discharge abnormality detection after the battery is manufactured.

[0069] Based on the above embodiments and optional embodiments, the present invention proposes an optional implementation mode: Figure 2 is a flow chart of an optional battery abnormality detection method according to an embodiment of the present invention, such as Figure 2 As shown, the method includes:

[0070] S01, obtaining a batch of assembled batteries as batteries to be tested;

[0071] The assembly includes assembling the positive electrode sheet and the negative electrode sheet into an electrode group, welding and sealing the electrode group in a shell, and baking and drying to obtain an assembled battery.

[0072] The positive electrode active material in the positive electrode slurry is one or more of lithium iron phosphate, lithium manganese oxide, lithium cobalt oxide, and ternary materials. The negative electrode active material in the negative electrode slurry is one or more of graphite, lithium titanate, silicon oxide, silicon carbon, and hard carbon. The positive electrode collector is aluminum foil, and the negative electrode collector is copper foil.

[0073] The electrode sheet composite method is stacking or winding, and a diaphragm is provided between the positive electrode sheet and the negative electrode sheet. The diaphragm is a dry PP diaphragm, a wet PE diaphragm, a ceramic diaphragm or a rubber-coated diaphragm. The shell is an aluminum shell or a soft bag. The baking method is air conveying or contact.

[0074] S02, placing the above-mentioned batteries to be tested at high temperature for soaking after being filled with liquid, and monitoring and recording the soaking voltage change curve of each battery to be tested in real time;

[0075] High temperature static is the process of placing the battery in a high temperature storage to allow the electrolyte to soak the electrodes and diaphragms. The temperature of the high temperature storage is > 42°C.

[0076] The wetting voltage is the difference between the potential of the positive metal in the electrolyte and the potential of the negative metal in the electrolyte, that is, the voltage between the positive and negative electrodes of the battery. The voltage monitoring and recording time is the high temperature immersion time of the battery, and its range is >48 hours.

[0077] S03, analyzing the voltage change curve of each battery under test during the infiltration process, determining the peak voltage V1 during the infiltration process and the ending voltage V2 at the end of the infiltration, and calculating the voltage difference between V1 and V2 of each battery. If the voltage difference is within a preset range, the battery under test is considered normal. Otherwise, the battery under test has abnormal self-discharge and is selected for elimination or downshifting.

[0078] The voltage difference between the peak voltage V1 of the battery during soaking and the voltage V2 at the end of soaking is proportional to the battery self-discharge. The greater the self-discharge, the greater the difference between V1 and V2. Battery self-discharge includes self-discharge caused by physical micro-short circuit factors such as dust, burrs, positive metal foreign matter and negative metal foreign matter. Positive metal foreign matter and negative metal foreign matter include one or more metals such as iron, nickel, copper, zinc, and chromium.

[0079] It should be noted that in the embodiment of the present invention, by monitoring and recording the voltage change curve of the battery during the high-temperature soaking process, the difference between the soaking peak voltage and the voltage at the end of soaking is calculated. If the difference is within a preset range, the battery is considered a normal battery, otherwise the battery is considered to have abnormal self-discharge. The voltage drop from the peak of the soaking voltage curve to the end of soaking can effectively screen out batteries with abnormal self-discharge. This process is carried out simultaneously with the high-temperature soaking, does not take up additional testing time, and batteries with abnormal self-discharge can be downgraded or scrapped, reducing the resource occupation of abnormal batteries in subsequent processes and improving production efficiency and production line yield.

[0080] Based on the above embodiments and optional embodiments, the present invention proposes another optional battery abnormality detection method, which monitors the voltage change of the battery during the infiltration process in real time, quickly determines the self-discharge size, and achieves the purpose of screening out abnormal self-discharge batteries in advance, reducing resource occupation and time waste. Specifically including:

[0081] Obtaining a batch of assembled batteries, wherein the assembly includes assembling positive electrode sheets and negative electrode sheets into an electrode group, welding and sealing the electrode group in a shell, and baking and drying to remove moisture;

[0082] After the battery is filled with electrolyte, it is placed at high temperature to allow the electrolyte to infiltrate the battery pole piece, and the infiltration voltage change curve of each battery is monitored and recorded in real time, wherein the high temperature static is the process of placing the battery in a high temperature storage to allow the electrolyte to infiltrate the electrode and the diaphragm, the infiltration voltage is the voltage between the positive and negative electrodes of the battery, the temperature of the high temperature storage is greater than 42°C, and the voltage monitoring and recording time is the high temperature infiltration time of the battery, and its range is greater than 48 hours;

[0083] Analyze the voltage change curve of each battery during the infiltration process, determine the infiltration peak voltage V1 and the voltage V2 at the end of infiltration, and calculate the difference between V1 and V2. If the difference is within the preset range, the battery is considered normal. Otherwise, the battery has self-discharge abnormality and is selected for removal or downshifting.

[0084] Based on the above embodiments and optional embodiments, the present invention proposes an optional real-time method for battery abnormality detection and method verification. In this embodiment, the positive electrode slurry active material of the battery is lithium iron phosphate, the positive electrode collector is aluminum foil, the negative electrode slurry active material is artificial graphite, the negative electrode collector is copper foil, a ceramic diaphragm is provided between the positive and negative electrode sheets, the composite method of the positive and negative electrode sheets is a stacked sheet, and the battery shell is an aluminum shell.

[0085] In this embodiment, the factor causing the battery self-discharge is the positive electrode metal foreign matter, and the specific implementation steps are as follows:

[0086] S11, the positive electrode slurry is applied to the two sides of the positive electrode current collector by a roller, and the positive electrode sheet is formed after drying; the negative electrode slurry is applied to the surface of the negative electrode current collector by a roller, and the negative electrode sheet is formed after drying. The positive and negative electrode sheets are cut and stacked with the separator to form an electrode group, wherein each electrode sheet is provided with a pole ear, and the positive and negative pole ears overlap after lamination.

[0087] S12, obtain step S11 12 pole groups, divided into 6 groups with 2 poles as a group, opened along the ear side of the positive pole piece, and placed pure iron powder with particle sizes of 150μm, 75μm, 48μm, 25μm, and 13μm between the positive pole piece and the diaphragm of each pole group, of which about 5 grains of 150μm iron powder, about 10 grains of 75μm iron powder, about 15 grains of 48μm iron powder, about 30 grains of 25μm iron powder, and about 50 grains of 13μm iron powder. The iron powder needs to be evenly distributed between the positive pole piece and the diaphragm to prevent agglomeration.

[0088] S13, sealing the 25 electrode groups in step S11 in a housing through a series of assembly processes to form 5 batteries, and baking to remove moisture from the electrode sheets.

[0089] S14. Inject electrolyte into 5 batteries, and take a battery that has been normally assembled, baked, and injected, and put it into a high-temperature storage for immersion. The temperature of the high-temperature storage is 45°C.

[0090] S15, continuously monitor and record the soaking voltage of 6 batteries for 72 hours. Figure 3 FIG. 1 is a schematic diagram of an optional wetting voltage detection result according to an embodiment of the present invention, wherein the result is as follows: Figure 3 shown.

[0091] from Figure 3 It can be seen that during the infiltration process, the infiltration voltage of the battery first rises with the infiltration time, reaches a peak value around 20 to 30 hours, and then continues to decline, and the rate of decline gradually decreases with time. Table 1 is the difference between the infiltration peak voltage of each battery and the voltage at the end of infiltration. It can be seen from Table 1 that the self-discharge caused by metal foreign matter in the battery cell will affect the infiltration voltage, increase the voltage difference from the infiltration peak voltage to the end of infiltration, and the degree of self-discharge caused by metal foreign matter of different particle sizes is different, and the larger the particle size, the greater the voltage difference. In summary, the method provided in this embodiment can screen out abnormal self-discharge batteries during battery infiltration, and simply judge the degree of self-discharge.

[0092] Table 1 Comparison of wetting voltage monitoring results

[0093]

[0094] In this embodiment, by detecting the voltage change of the battery during the soaking process and calculating the difference between the peak voltage and the voltage at the end of soaking, it is determined whether it is within the preset range, thereby effectively screening out abnormal self-discharge batteries. This process is carried out simultaneously with high-temperature soaking, does not take up additional test time, and abnormal self-discharge batteries can be downgraded or scrapped, reducing the resource occupation of abnormal batteries in subsequent processes and improving production efficiency and production line yield.

[0095] Based on the above embodiments and optional embodiments, the present invention proposes another optional implementation mode: Figure 4 is a schematic diagram of an optional battery abnormality detection system structure according to an embodiment of the present invention, such as Figure 4 As shown, the system includes: a high temperature immersion module 1 and a battery to be tested 2 placed therein, a data acquisition module 3, a data processing module 4, and a data analysis module 5, wherein:

[0096] The high temperature soaking module 1 is used to obtain the assembled battery, inject electrolyte into the battery, and put it into a high temperature reservoir to start soaking, wherein the temperature of the high temperature reservoir is greater than 42°C.

[0097] The data acquisition module 3 is used to monitor and record the infiltration voltage change curve of the battery 2 to be tested;

[0098] The voltage monitoring and recording time is the time of high temperature immersion of the battery, and its range is > 48 hours. The immersion voltage is the difference between the potential of the positive electrode metal in the electrolyte and the potential of the negative electrode metal in the electrolyte, that is, the voltage between the positive and negative electrodes of the battery.

[0099] Data processing module 4, used for smoothing the infiltration voltage curve and filtering out the small voltage fluctuation caused by the temperature fluctuation of the high temperature storage;

[0100] The smoothing curve method is one of the methods such as sliding average filtering, exponential sliding average filtering, and Savitzky-Golay filtering.

[0101] Data analysis module 5, used to obtain the peak voltage V1 of the soaking and the voltage V2 at the end of the soaking, and calculate the difference between V1 and V2. If the voltage difference is within a preset range, the battery is considered normal. Otherwise, the battery has abnormal self-discharge and is selected for elimination or downshifting.

[0102] Among them, the method for determining the peak value of the battery soaking voltage curve is one of the peak calculation methods such as the difference method and the dichotomy method; the difference between the battery soaking peak voltage V1 and the voltage V2 at the end of soaking is proportional to the battery self-discharge. The greater the self-discharge, the greater the difference between V1 and V2.

[0103] In this embodiment, a battery abnormality detection device is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made will not be repeated. As used below, the terms "module" and "device" can implement a combination of software and / or hardware for a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0104] According to an embodiment of the present invention, a device embodiment for implementing the above-mentioned battery abnormality detection method is also provided. Figure 5 is a schematic diagram of the structure of a battery abnormality detection device according to an embodiment of the present invention. Figure 5 As shown, the battery abnormality detection device comprises: an electrolyte injection control module 500, a voltage change curve acquisition module 502, and a detection result determination module 504, wherein:

[0105] The electrolyte injection control module 500 is used to control the injection of electrolyte into the battery to be tested in response to receiving the electrolyte injection instruction, so that the electrolyte infiltrates the electrode of the battery to be tested;

[0106] A voltage variation curve acquisition module 502, connected to the electrolyte injection control module 500, for acquiring a voltage variation curve of the battery under test during the infiltration process;

[0107] The detection result determination module 504 is connected to the voltage change curve acquisition module 502, and is used to determine the abnormal detection result of the battery to be tested based on the voltage change curve, wherein the abnormal detection result is at least used to indicate whether the battery to be tested has self-discharge abnormality.

[0108] In an embodiment of the present invention, an electrolyte injection control module 500 is provided for controlling the injection of electrolyte into the battery to be tested in response to receiving an electrolyte injection instruction, so that the electrolyte infiltrates the electrode of the battery to be tested; a voltage change curve acquisition module 502 is connected to the electrolyte injection control module 500, and is used to obtain the voltage change curve of the battery to be tested during the infiltration process; a detection result determination module 504 is connected to the voltage change curve acquisition module 502, and is used to determine the abnormal detection result of the battery to be tested based on the voltage change curve, wherein the abnormal detection result is at least used to indicate whether the battery to be tested has a self-discharge abnormality, thereby achieving the purpose of collecting the voltage change curve and analyzing the voltage in the electrolyte infiltration link in the battery manufacturing process to determine whether the battery to be tested has an abnormality, thereby achieving the technical effect of performing battery self-discharge abnormality detection in the battery manufacturing process and improving the battery self-discharge detection efficiency, thereby solving the technical problem of low detection efficiency in the related art of performing battery self-discharge abnormality detection after the battery is manufactured.

[0109] It should be noted that the above modules can be implemented by software or hardware. For example, for the latter, it can be implemented in the following ways: the above modules can be located in the same processor; or the above modules can be located in different processors in any combination.

[0110] It should be noted that the electrolyte injection control module 500, the voltage change curve acquisition module 502, and the detection result determination module 504 correspond to steps S102 to S106 in the embodiment, and the examples and application scenarios implemented by the modules and the corresponding steps are the same, but are not limited to the contents disclosed in the above embodiments. It should be noted that the modules as part of the device can be run in a computer terminal.

[0111] It should be noted that the optional or preferred implementation of this embodiment can refer to the relevant description in the embodiment, which will not be repeated here.

[0112] The above-mentioned battery abnormality detection device may also include a processor and a memory. The above-mentioned electrolyte injection control module 500, voltage change curve acquisition module 502, detection result determination module 504, etc. are all stored in the memory as program modules, and the processor executes the above-mentioned program modules stored in the memory to realize the corresponding functions.

[0113] The processor includes a kernel, which retrieves the corresponding program module from the memory. The kernel may be one or more. The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. The memory includes at least one memory chip.

[0114] According to an embodiment of the present application, an embodiment of a non-volatile storage medium is also provided. Optionally, in this embodiment, the non-volatile storage medium includes a stored program, wherein when the program is executed, the device where the non-volatile storage medium is located is controlled to execute any of the above-mentioned battery abnormality detection methods.

[0115] Optionally, in this embodiment, the non-volatile storage medium may be located in any computer terminal in a computer terminal group in a computer network, or in any mobile terminal in a mobile terminal group, and the non-volatile storage medium includes a stored program.

[0116] Optionally, when the program is running, the device where the non-volatile storage medium is located is controlled to perform the following functions: in response to receiving an electrolyte injection instruction, controlling the injection of electrolyte into the battery to be tested so that the electrolyte infiltrates the electrode of the battery to be tested; obtaining a voltage change curve of the battery to be tested during the infiltration process; based on the voltage change curve, determining an abnormal detection result of the battery to be tested, wherein the abnormal detection result is at least used to indicate whether the battery to be tested has a self-discharge abnormality.

[0117] According to an embodiment of the present application, an embodiment of a processor is also provided. Optionally, in this embodiment, the processor is used to run a program, wherein when the program is run, any one of the battery abnormality detection methods is executed.

[0118] According to an embodiment of the present application, an embodiment of a computer program product is also provided. When executed on a data processing device, it is suitable for executing a program that initializes any one of the above-mentioned battery abnormality detection method steps.

[0119] Optionally, the above-mentioned computer program product, when executed on a data processing device, is suitable for executing a program that initializes the following method steps: in response to receiving an electrolyte injection instruction, controlling the injection of electrolyte into the battery to be tested so that the electrolyte infiltrates the electrode of the battery to be tested; obtaining a voltage change curve of the battery to be tested during the infiltration process; based on the voltage change curve, determining an abnormal detection result of the battery to be tested, wherein the abnormal detection result is at least used to indicate whether the battery to be tested has a self-discharge abnormality.

[0120] An embodiment of the present invention provides an electronic device, which includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, the following steps are implemented: in response to receiving an electrolyte injection instruction, controlling the injection of electrolyte into a battery to be tested so that the electrolyte infiltrates a pole piece of the battery to be tested; obtaining a voltage change curve of the battery to be tested during the infiltration process; and determining an abnormal detection result of the battery to be tested based on the voltage change curve, wherein the abnormal detection result is at least used to indicate whether the battery to be tested has a self-discharge abnormality.

[0121] The above sequence of the embodiments of the present invention is for description only and does not represent the superiority or inferiority of the embodiments.

[0122] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0123] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the above modules can be a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, modules or indirect coupling or communication connection of modules, which can be electrical or other forms.

[0124] The modules described above as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0125] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of software functional modules.

[0126] If the above-mentioned integrated module is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable non-volatile storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a non-volatile storage medium, including a number of instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the various embodiments of the present invention. The aforementioned non-volatile storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0127] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A battery abnormality detection method, characterized in that: include: In response to receiving an electrolyte injection instruction, controlling the electrolyte to be injected into the battery to be tested so that the electrolyte infiltrates the electrode of the battery to be tested; Obtaining a voltage variation curve of the battery under test during the soaking process; Based on the voltage variation curve, an abnormality detection result of the battery to be tested is determined, wherein the abnormality detection result is at least used to indicate whether the battery to be tested has a self-discharge abnormality.

2. The method according to claim 1, characterized in that The controlling of injecting electrolyte into the battery to be tested so that the electrolyte infiltrates the electrode of the battery to be tested includes: After controlling the electrolyte to be injected into the battery to be tested, controlling the battery to be tested to be placed in a high temperature environment for static treatment, so that the electrolyte infiltrates the pole piece of the battery to be tested.

3. The method according to claim 2, characterized in that The obtaining of the voltage change curve of the battery to be tested during the soaking process includes: Collecting the temperature in the high temperature environment; When the temperature is greater than a preset temperature threshold, the voltage change curve of the battery to be tested during the soaking process is collected.

4. The method according to claim 1, characterized in that: The obtaining of the voltage change curve of the battery to be tested during the soaking process includes: During the soaking process, obtaining soaking voltages of the battery to be tested corresponding to a plurality of sampling moments respectively; constructing an initial voltage curve based on the wetting voltages corresponding to the plurality of sampling moments; The initial voltage curve is smoothed to obtain the voltage variation curve.

5. The method according to claim 4, characterized in that In the soaking process, obtaining soaking voltages corresponding to the battery to be tested at multiple sampling moments respectively includes: During the soaking process, the soaking voltage of the battery to be tested at any sampling time among the multiple sampling times is obtained in the following manner: Acquire a first potential of the positive electrode sheet of the battery to be tested in the electrolyte at any sampling moment, and a second potential of the battery to be tested in the electrolyte; calculating a potential difference between the first potential and the second potential; Taking the potential difference as the wetting voltage at any sampling moment; The wetting voltages corresponding to the plurality of sampling moments are obtained by obtaining the wetting voltage at any sampling moment.

6. The method according to claim 1, characterized in that The determining, based on the voltage change curve, an abnormality detection result of the battery to be tested, comprises: Determining a peak voltage in the voltage variation curve and an end voltage at the end of the wetting process; determining a voltage difference between the peak voltage and the end voltage; Based on the voltage difference, an abnormality detection result of the battery to be tested is determined.

7. The method according to claim 6, characterized in that The determining, based on the voltage difference, an abnormality detection result of the battery to be tested, comprises: Determining whether the voltage difference is greater than a preset difference threshold; In the case where the voltage difference is greater than the preset difference threshold, determining the abnormality detection result as: the battery to be tested has a self-discharge abnormality; When the voltage difference is less than or equal to the preset difference threshold, the abnormality detection result is determined as: the battery to be tested does not have a self-discharge abnormality.

8. The method according to claim 6 or 7, characterized in that: The self-discharge includes self-discharge caused by one or more factors of dust, burrs, positive electrode metal foreign matter and negative electrode metal foreign matter; the voltage difference is proportional to the degree of the self-discharge.

9. A battery abnormality detection device, characterized in that: include: An electrolyte injection control module, for controlling the injection of electrolyte into the battery to be tested in response to receiving an electrolyte injection instruction, so that the electrolyte infiltrates the electrode of the battery to be tested; A voltage change curve acquisition module, used to acquire a voltage change curve of the battery to be tested during the soaking process; The detection result determination module is used to determine the abnormal detection result of the battery to be tested based on the voltage change curve, wherein the abnormal detection result is at least used to indicate whether the battery to be tested has self-discharge abnormality.

10. An electronic device, characterized in that: It includes one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the battery abnormality detection method described in any one of claims 1 to 8.

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