Lithium battery anomaly detection method and device, battery system and electric vehicle

Abstract

The invention provides an anomaly detection method and device of a lithium battery, a battery system and an electric vehicle, after a controller obtains a first electrolyte steam concentration, the change condition of the electrolyte steam concentration is calculated, and whether the lithium battery is abnormal or not is determined according to the first electrolyte steam concentration and the change condition of the electrolyte steam concentration. According to the embodiment of the invention, the types and the number of sensors in the anomaly detection device are reduced, so that the internal space of the lithium battery occupied by the sensors is reduced, the overall volume energy density of the lithium battery is improved, and the power consumption and the cost of the lithium battery are reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a lithium battery abnormality detection method, device, battery system and electric vehicle. Background Art

[0002] With the continuous development of new energy technologies, lithium batteries are widely used in various vehicles and equipment. Since the safety of lithium batteries is an important factor affecting the promotion and use of new energy technologies, lithium battery manufacturers need to detect in real time whether there are abnormalities such as battery leakage and thermal runaway during the use of lithium batteries. Once an abnormality occurs, it is necessary to stop using the lithium battery and repair and replace the lithium battery in combination with the abnormality to prevent more serious safety problems caused by the abnormality of the lithium battery.

[0003] With existing technologies, abnormality detection of lithium batteries requires analysis of data from a variety of different sensors, which results in a large number of sensors being installed inside the lithium battery. These sensors occupy a large amount of internal space of the lithium battery. Summary of the invention

[0004] The present application provides a lithium battery abnormality detection method, device, battery system and electric vehicle to overcome the technical problem in the prior art that a large number of types and quantities of sensors are required to perform abnormality detection on lithium batteries, thereby achieving abnormality detection on lithium batteries with fewer sensors, reducing the space occupied by sensors and abnormality detection devices in the lithium battery interior.

[0005] In a first aspect, the present application provides a method for detecting an abnormality of a lithium battery, comprising: obtaining a first electrolyte vapor concentration in an internal space of a lithium battery at a first moment; determining a change in electrolyte vapor concentration in the internal space of the lithium battery at the first moment based on the first electrolyte vapor concentration and a second electrolyte vapor concentration at a second moment before the first moment; and determining whether the lithium battery is abnormal based on the first electrolyte vapor concentration and the change in electrolyte vapor concentration.

[0006] The second aspect of the present application provides a lithium battery abnormality detection device, comprising: a controller and at least one concentration sensor, the controller is connected to the at least one concentration sensor, the at least one concentration sensor is arranged in the battery pack of the lithium battery, and is used to detect the concentration of electrolyte gas in the battery pack and send it to the controller; the controller is configured to execute the method described in the first aspect of the present application.

[0007] A third aspect of the present application provides a battery system, comprising: a lithium battery and a lithium battery abnormality detection device as described in the second aspect of the present application, wherein the lithium battery abnormality detection device is used to detect whether the lithium battery is abnormal.

[0008] A fourth aspect of the present application provides an electric vehicle, comprising a battery system as provided in the third aspect of the present application.

[0009] In summary, in the lithium battery abnormality detection method, device, battery system and electric vehicle provided by the present application, the controller can obtain the first electrolyte vapor concentration, calculate the change in the electrolyte vapor concentration, and thus determine whether the lithium battery has an abnormality based on the first electrolyte vapor concentration and the change in the electrolyte vapor concentration. Among them, since the controller simultaneously realizes the detection of leakage abnormality and thermal runaway abnormality based on the parameter of electrolyte vapor concentration, it is not necessary to set up sensors for detecting leakage abnormality and thermal runaway abnormality respectively in the abnormality detection device, but only need to set up concentration sensors, thereby reducing the occupation of the internal space of the lithium battery, thereby improving the overall volume energy density of the lithium battery, and reducing the power consumption and cost of the lithium battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0011] Figure 1 It is a structural schematic diagram of a lithium battery abnormality detection device in the prior art;

[0012] Figure 2 A schematic structural diagram of an embodiment of a lithium battery abnormality detection device provided in the present application;

[0013] Figure 3 A schematic diagram of a flow chart of an embodiment of a method for detecting abnormality of a lithium battery provided in the present application;

[0014] Figure 4 A schematic diagram of a flow chart of another embodiment of the abnormality detection method for a lithium battery provided in the present application;

[0015] Figure 5 A schematic diagram of the three-dimensional structure of an abnormality detection device for a lithium battery provided in the present application;

[0016] Figure 6 A schematic diagram of the planar structure of an abnormality detection device for a lithium battery provided in the present application;

[0017] Figure 7 A schematic diagram of the external structure of an embodiment of a concentration sensor provided by the present application;

[0018] Figure 8A schematic diagram of the internal structure of an embodiment of a concentration sensor provided by the present application;

[0019] Fig. 9 A schematic diagram of the structure of a lithium battery abnormality detection device provided in the present application;

[0020] Fig.10 A schematic diagram of the structure of a lithium battery abnormality detection device provided in this application. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0022] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application 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 interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] Figure 1 FIG. 1 is a schematic diagram of a structure of a lithium battery abnormality detection device in the prior art. Figure 1 The abnormality detection device shown includes a controller 14 and a plurality of sensors. Figure 1 In the example shown, the abnormality detection device of the lithium battery 1 includes sensor A and sensor B, and the sensor A and sensor B are respectively connected to the controller 14. The sensor A and the sensor B are specifically arranged in the internal space of the battery pack of the lithium battery 1, and at least one battery cell 10 and a battery management system (Battery Management System, BMS for short) 16 are also arranged inside the battery pack. The controller 14 is also connected to the BMS 16, and the BMS 16 is also connected to the battery cell 10.

[0024] In one embodiment, the sensor A may be a liquid detection sensor, etc., for detecting whether the lithium battery 1 has abnormal leakage. The abnormal leakage is caused by the battery cell 10 leaking liquid when the lithium battery 1 is impacted by external force, the battery cell is expanded and deformed, abused, the welding package is not firm, or there is an internal short circuit. Specifically, when liquid is detected, the sensor A sends a first detection signal to the controller 14, so that the controller 14 determines that the lithium battery 1 has abnormal leakage according to the first detection signal of the sensor A.

[0025] Sensor B may be a temperature sensor, etc., and is used to detect whether a thermal runaway abnormality has occurred in the lithium battery 1. The thermal runaway abnormality is caused by overheating, overcharging, internal short circuit, etc. Specifically, when a temperature rise is detected, sensor B sends a second detection signal to the controller 14, so that the controller 14 determines that a thermal runaway abnormality has occurred in the lithium battery 1 according to the second detection signal of sensor B. Subsequently, when it is determined that an abnormality has occurred in the lithium battery 1, the controller 14 sends abnormal information to the BMS 16, so that the BMS 16 determines that it is necessary to stop using the lithium battery 1 according to the abnormal information, and prompts the user to repair and replace the lithium battery 1 in combination with the abnormality, so as to prevent more serious safety problems caused by the abnormality of the lithium battery in the future.

[0026] In the above embodiment, in order to determine the different abnormalities occurring in the lithium battery 1, the abnormality detection device of the lithium battery 1 needs to set a corresponding sensor for each abnormality, for example, sensor A is used to detect leakage abnormality, sensor B is used to detect thermal runaway abnormality, etc. Since each sensor can only be used to detect one abnormality, when there are many abnormal conditions of the lithium battery 1 that need to be detected, more types and a larger number of sensors need to be set in the abnormality detection device. These sensors and the required wiring harnesses greatly occupy the already limited space inside the lithium battery 1, reduce the overall volume energy density of the lithium battery 1, and increase the power consumption and cost of the lithium battery 1. At the same time, the controller 14 in the above embodiment can only analyze the detection data of each sensor separately, and can only determine whether the lithium battery 1 has a certain abnormality based on the detection data of one sensor. This method of determining whether the lithium battery 1 has an abnormality has a low degree of intelligence, which is not conducive to the promotion and application of the abnormality detection device.

[0027] Based on this, the present application provides an abnormality detection device for a lithium battery 1 and a corresponding detection method to reduce the types and number of sensors provided in the abnormality detection device, and enable the controller 14 to simultaneously detect multiple abnormalities of the lithium battery 1 based on fewer types and numbers of sensors. The technical solution of the present application is described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0028] Figure 2This is a structural diagram of an embodiment of a lithium battery abnormality detection device provided in the present application, such as Figure 2 The abnormality detection device of the lithium battery 1 shown includes: a controller 14 and a concentration sensor 13. The controller 14 is connected to the concentration sensor 13, and both the controller 14 and the concentration sensor 13 are arranged in the battery pack of the lithium battery 1. The battery pack of the lithium battery 1 is also provided with a battery cell 10 and a BMS 16, and the controller 14 is also connected to the BMS and the battery cell 10.

[0029] The concentration sensor 13 may be a device that is sensitive to the vapor of the electrolyte in the battery cell 10 of the lithium battery 1, such as a micro-electro-mechanical system (MEMS) chip. The concentration sensor 13 may be used to detect the gas in the internal space of the lithium battery 1, thereby obtaining the concentration of the electrolyte in the form of gas and sending it to the controller 14. The electrolyte in the battery cell 10 of the lithium battery 1 includes: volatile organic compounds (VOC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), ethylene carbonate (EC), vinylene carbonate (VC), fluoroethylene carbonate (FEC), etc.

[0030] The controller 14 can receive the electrolyte vapor concentration sent by the concentration sensor 13, and determine whether the lithium battery 1 is abnormal according to the electrolyte vapor concentration. Specifically, Figure 3 This is a flow chart of an embodiment of a method for detecting abnormality of a lithium battery provided in the present application, as shown in FIG. Figure 3 The method shown can be used as Figure 2 The controller 14 shown executes, as Figure 3 The anomaly detection methods shown include:

[0031] S101: the controller 14 obtains the first electrolyte vapor concentration.

[0032] Specifically, the controller 14 may obtain the first electrolyte vapor concentration sent by the concentration sensor 13. The first electrolyte vapor concentration is obtained by the concentration sensor 13 at the first moment and sent to the controller 14, and the first electrolyte vapor concentration is used to indicate the electrolyte gas distribution in the internal space of the lithium battery 1 at the first moment. The controller 14 may control the concentration sensor 13 to detect the electrolyte vapor concentration at intervals, or the concentration sensor 13 may detect the electrolyte vapor concentration at intervals and send it to the controller 14.

[0033] In one embodiment, the abnormality detection device of the lithium battery 1 may also be provided with a plurality of concentration sensors 13, each of which may be used to detect the concentration of electrolyte vapor liquid at different positions in the internal space of the lithium battery 1 and send the concentration to the controller 14. Then, the controller 14 may perform subsequent processing on the electrolyte vapor concentration sent by each concentration sensor 13 as the first electrolyte vapor concentration, or may calculate the average value of the electrolyte vapor concentrations sent by all the plurality of concentration sensors 13 to obtain the first electrolyte vapor concentration.

[0034] When an abnormality occurs in the lithium battery 1, the change of the gas signal is faster and most obvious than the change of voltage and temperature caused by the abnormality, and the change of the gas signal can be detected at the beginning of the abnormality. At the same time, since the diffusion of gas is faster than the flow of liquid and can diffuse in the internal space of the entire lithium battery 1, the concentration sensor 13 is used to detect the concentration of gas to judge the abnormality of the lithium battery 1. The sensitivity is higher and there are fewer restrictions on the position and parameters of the concentration sensor 13.

[0035] S102: The controller 14 determines the change of the electrolyte vapor concentration in the internal space of the lithium battery 1 based on the first electrolyte vapor concentration obtained in S101 and the stored second electrolyte vapor concentration.

[0036] Specifically, the controller 14 calculates the current electrolyte vapor concentration change according to the first electrolyte vapor concentration at the current first moment and the second electrolyte vapor concentration before the first moment. The second moment may be a moment of a preset time before the first moment, or may be a moment when the controller 14 receives the second electrolyte vapor concentration before the concentration sensor 13.

[0037] The controller 14 specifically obtains the change of the electrolyte vapor concentration in the internal space of the lithium battery 1 between the second moment and the first moment according to the difference between the first electrolyte vapor concentration and the second electrolyte vapor concentration, divided by the difference between the first moment and the second moment. The change of the electrolyte vapor concentration may be the increase rate of the electrolyte vapor concentration.

[0038] S103: The controller 14 determines whether the lithium battery 1 is abnormal based on the first electrolyte vapor concentration obtained in S101 and the change in electrolyte vapor concentration determined in S102.

[0039] Specifically, the controller 14 provided in this embodiment determines whether the lithium battery 1 has an abnormality, including: determining whether the lithium battery 1 has a leakage abnormality and a thermal runaway abnormality. That is, the controller 14 can determine whether the lithium battery 1 has a leakage abnormality or a thermal runaway abnormality, or determine that the lithium battery 1 has no abnormality, based on the first electrolyte vapor concentration and the electrolyte vapor concentration increase rate.

[0040] In one embodiment, the change in electrolyte vapor concentration specifically refers to the rate of increase of electrolyte vapor concentration. The controller 14 compares the first electrolyte vapor concentration C with two thresholds corresponding to the electrolyte vapor concentration: a first concentration preset value C1 and a second concentration preset value C2, and compares the electrolyte vapor concentration increase rate V with two thresholds corresponding to the electrolyte vapor concentration increase rate: a first speed preset value V1 and a second speed preset value, thereby starting from the perspective of electrolyte vapor concentration, evaluating the two dimensions of concentration and change rate, and finally determining whether the lithium battery 1 is abnormal.

[0041] In one embodiment, the controller 14 can further determine whether the lithium battery 1 has leakage anomaly according to the electrolyte vapor concentration increase rate V and the first electrolyte vapor concentration C when the electrolyte vapor concentration increase rate V is less than the second speed preset value V2. The controller 14 can also further determine whether the lithium battery 1 has thermal runaway anomaly according to the first electrolyte vapor concentration C when the electrolyte vapor concentration increase rate V is greater than or equal to the second speed preset value V2. Wherein, based on the fact that when the lithium battery 1 has thermal runaway anomaly, the electrolyte gas will be ejected from the end of the battery cell 10, resulting in a faster increase rate of the electrolyte vapor concentration in the internal space of the lithium battery 1, and when the lithium battery 1 has leakage anomaly, the concentration of the electrolyte vapor in the form of liquid in the internal space of the lithium battery 1 is low and the speed is slow to form the electrolyte vapor in the form of gas by evaporation. Therefore, the controller 14 can determine whether the lithium battery 1 has thermal runaway anomaly by the change of the electrolyte vapor concentration. In this embodiment, the controller 14 does not need to determine whether the lithium battery 1 has thermal runaway anomaly by temperature parameters.

[0042] In summary, in the abnormality detection method of the lithium battery 1 provided in this embodiment, the controller 14 can obtain the first electrolyte vapor concentration, calculate the change of the electrolyte vapor concentration, and determine whether the lithium battery has leakage abnormality and thermal runaway abnormality according to the first electrolyte vapor concentration and the change of the electrolyte vapor concentration. Since the controller 14 realizes the detection of leakage abnormality and thermal runaway abnormality at the same time according to the parameter of electrolyte vapor concentration, it is not necessary to set up a sensor for detecting leakage abnormality and a sensor for detecting thermal runaway abnormality in the abnormality detection device at the same time, but only needs to set up a concentration sensor, and the controller 14 judges whether the lithium battery 1 has two abnormalities according to the electrolyte vapor concentration. Therefore, the electrolyte abnormality detection device of the lithium battery 1 provided in this embodiment can realize the detection of multiple abnormalities without setting up a large number of types and quantities of sensors, and the concentration sensor 13 and the abnormality detection device occupy a relatively limited space inside the lithium battery 1, thereby improving the overall volume energy density of the lithium battery 1 and reducing the power consumption and cost of the lithium battery 1. At the same time, the controller 14 can detect whether the lithium battery 1 has leakage anomalies and thermal runaway anomalies through the electrolyte vapor concentration, so that the controller 14 has a higher degree of intelligence and is more conducive to the promotion and application of abnormality detection devices.

[0043] In conjunction with Table 3, several methods for the controller 14 to determine whether there is an abnormality in the lithium battery according to the first electrolyte vapor concentration C and the electrolyte vapor concentration increase value V are introduced below.

[0044] Table 1

[0045] V<V1 V1≤V<V2 V2≤V C<C1 11. No abnormality 12. Risk of leakage 13. Risk of leakage C1≤C<C2 21. Risk of leakage 22. Abnormal leakage 23. Thermal runaway risk C2≤C 31. Risk of leakage 32. Abnormal leakage 33. Thermal runaway anomaly

[0046] 11. No abnormality: When the first electrolyte vapor concentration C is less than the first concentration preset value C1, and the concentration increase rate V is less than the first speed preset value V1, it means that the electrolyte solvent vapor concentration value in the internal space of the battery pack of the lithium battery 1 is low and remains stable. Then the controller 14 determines that the lithium battery 1 is normal and there is no abnormality, that is, the lithium battery 1 does not have leakage abnormality or thermal runaway abnormality.

[0047] 22, 32, leakage abnormality: When the first electrolyte vapor concentration C is greater than or equal to the first concentration preset value C1 (including 22, the first electrolyte vapor concentration C is less than the second concentration preset value and 32, the first electrolyte vapor concentration C is greater than the second concentration preset value C2 at the same time), and the concentration increase rate V is less than the second rate preset value V2, it means that the electrolyte solvent vapor concentration in the internal space of the battery pack of the lithium battery 1 is increasing at a certain rate and has risen to a higher concentration, then the controller 14 determines that the lithium battery 1 has a leakage abnormality.

[0048] 33: Thermal runaway anomaly: When the first electrolyte vapor concentration C is greater than the second concentration preset value C2, and the concentration increase rate V is greater than the second speed preset value V2, it means that the electrolyte solvent vapor concentration in the internal space of the battery pack of the lithium battery 1 is increasing at a faster rate and has risen to a higher concentration. This change in electrolyte vapor concentration is caused by the electrolyte gas ejected from the battery cell 10 due to thermal runaway, and the controller 14 determines that the lithium battery 1 has a thermal runaway anomaly.

[0049] 12, 13, 21, 31 Leakage risk: When the first electrolyte vapor concentration C is greater than or equal to the first concentration preset value C1, and the concentration increase rate V is greater than or equal to the first speed preset value V1, and only one of these two conditions is met, it means that the electrolyte solvent vapor concentration in the internal space of the battery pack of the lithium battery 1 is increasing at a certain rate, or has risen to a certain concentration. At this time, the following situations may occur: the battery cell 10 has leaked, is leaking, or the sensor is interfered with, etc. The controller 14 cannot directly determine that the lithium battery 1 must have an abnormality, then the controller 14 determines that the lithium battery 1 is at risk of leakage.

[0050] Specifically, the above situations include: 12. The first electrolyte vapor concentration C is less than the first concentration preset value C1, and the concentration increase rate V is greater than or equal to the first speed preset value V1 and less than the second speed preset value V2. 13. The first electrolyte vapor concentration C is less than the first concentration preset value C1, and the concentration increase rate V is greater than the second speed preset value V2. 21. The first electrolyte vapor concentration C is greater than or equal to the first concentration preset value C1, less than the second concentration preset value C2, and the concentration increase rate V is less than the first speed preset value V1. 31. The first electrolyte vapor concentration C is greater than the second concentration preset value C2, and the concentration increase rate V is less than the first speed preset value V1.

[0051] 23. Thermal runaway risk: The first electrolyte vapor concentration C is greater than or equal to the first concentration preset value C1 and less than the second concentration preset value C2, and the concentration increase rate V is greater than the second rate preset value V2, indicating that the electrolyte solvent vapor concentration in the internal space of the battery pack of the lithium battery 1 is increasing at a relatively high rate, but the concentration is still relatively low. At this time, it may be that the thermal runaway abnormality of the lithium battery 1 causes the electrolyte vapor to diffuse, but the concentration diffused to the sensor position is relatively low, then the controller 14 determines that the lithium battery 1 has a thermal runaway risk.

[0052] In summary, in the abnormality detection method provided in this embodiment, the controller 14 compares the first electrolyte vapor concentration C and the concentration increase rate V with the corresponding threshold values, thereby determining the abnormalities that may exist in different situations. The comparison of the two dimensions can effectively avoid inaccurate detection caused by sensor failure and environmental interference, so that the abnormality detection method provided in this embodiment has a high accuracy. At the same time, since the threshold value includes at least two, the detection granularity of the abnormality detection method is also increased, and the detection of abnormalities in different abnormal situations and the detection of abnormal risks in the absence of abnormalities can be realized, which further improves the intelligence of the controller 14 and enriches the abnormality detection scenarios.

[0053] In one embodiment, as shown in Table 1, the first concentration preset value C1 is less than the second concentration preset value C2, and the first speed preset value V1 is less than the second speed preset value. These preset values ​​may be preset empirical values, may be obtained by analyzing experimental data, or may be set by the controller 14 based on the current operating parameters of the lithium battery 1, thereby improving the flexibility of the controller 14 in performing abnormality detection.

[0054] Figure 4 This is a flow chart of another embodiment of the abnormality detection method for a lithium battery provided in the present application, such as Figure 4 The method shown in Figure 2 Based on the embodiment shown, it also includes:

[0055] S104: When it is determined through S103 that the lithium battery 1 has an abnormality, the controller 14 outputs abnormal information. Among them, referring to Table 1, the controller 14 can send abnormal information to BMS16 after determining that the lithium battery 1 has a leakage abnormality or a thermal runaway abnormality, and the abnormal information includes information such as the type of abnormality currently occurring. After receiving the abnormal information, BMS16 can perform subsequent processing according to the abnormal information, for example, control the lithium battery 1 to stop working, send the abnormal information to the background or user, turn on the active insurance of the lithium battery 1, etc. Therefore, the abnormality detection method provided in this embodiment also has a high degree of intelligence, and can be more actively and automatically processed according to the abnormality after the abnormality occurs, which reduces the abnormality detection and processing required by the user of the lithium battery 1 to a certain extent, and can improve the user experience of the lithium battery 1 and the equipment in which it is located.

[0056] In one embodiment, if Figure 4In the method shown, after S102, it also includes: S203: Determine whether the lithium battery has an abnormal risk of leakage or an abnormal risk of thermal runaway based on the first electrolyte vapor concentration and the change in the electrolyte vapor concentration. S204: When it is determined that the lithium battery has an abnormal risk, the controller 14 outputs abnormal risk information. Among them, referring to Table 1, after the controller 14 determines that the lithium battery has an abnormal risk of leakage or an abnormal risk of thermal runaway, it can send abnormal risk information to BMS16, and the abnormal risk information includes information about abnormal risks that may occur at present. After receiving the abnormal risk information, BMS16 can perform subsequent processing according to the abnormal risk information. For example, BMS16 determines whether it is necessary to control the lithium battery 1 to stop working in advance, send the abnormal information to the background or the user, and determine whether to turn on the active insurance of the lithium battery 1 based on the abnormal risk information. In summary, the abnormality detection method provided in this embodiment is based on the higher-granularity detection in Table 1, and can determine the abnormality risk in advance before the actual abnormality occurs, so that the abnormality of the lithium battery 1 can be handled more promptly and effectively before the abnormality occurs, thereby preventing subsequent abnormalities from causing actual damage to the lithium battery 1 and more serious safety problems, further improving the service life and experience of the lithium battery 1 and the equipment in which it is located.

[0057] Figure 5 This is a three-dimensional structural diagram of an embodiment of a lithium battery abnormality detection device provided in the present application, as shown in Figure 5 The overall structure of the lithium battery 1 and the space in which the abnormality detection device is set inside the lithium battery 1 are shown, wherein the battery pack of the lithium battery 1 includes: a tray 11, an upper cover plate 12 and at least one battery cell 10, and the at least one battery cell 10 is arranged in parallel in the space between the tray 11 and the upper cover plate 12.

[0058] Specifically, Figure 5 As shown, the tray 11 and the upper cover 12 can be enclosed to form the internal space of the lithium battery 1 . Furthermore, the tray 11 is divided into two parts, which are denoted as a first part 101 and a second part 102 . Figure 6 This is a schematic diagram of the planar structure of an embodiment of a lithium battery abnormality detection device provided in the present application, as shown in FIG. Figure 6 Shows Figure 5 The tray 11 of the lithium battery shown is a plan view from the z direction, wherein at least one battery cell 10 of the lithium battery 1 is sequentially arranged parallel to the y direction and arranged in the second part 102 of the internal space formed by the tray 11 and the upper cover plate 12, each battery cell 10 is fixed to the bottom of the tray 11 and separated from each other by the grooves at the bottom of the tray 11, and each battery cell 10 is arranged in a groove. The first part 101 of the internal space formed by the tray 11 and the cover plate 12 is used to accommodate the BMS 16 of the lithium battery 1.

[0059] like Figure 6The at least one battery cell 10 shown includes a cylindrical battery, a square shell battery, a soft pack battery, etc. The lithium battery 1 provided in the embodiment of the present application can also be a lithium ion battery, a lithium metal battery, a sodium ion battery, etc. An airway space 102 is formed between one end of the at least one battery cell 10 and the side wall of the tray 11, for example Figure 6 In the example shown, an upper end of at least one battery cell 10 and a side wall of the tray 11 form an air passage space 1022 , and a lower end of at least one battery cell 10 and a side wall of the tray 11 form an air passage space 1021 .

[0060] In one embodiment, when the lithium battery 1 has a leakage anomaly, the electrolyte generally flows out from the end of the battery cell 10, and when the lithium battery 1 has a thermal runaway anomaly, the thermal runaway gas generally sprays out from the explosion-proof valve at the end of the battery cell 10. Therefore, the end positions on both sides of the battery cell 10 are most likely to produce electrolyte solvent vapor. Therefore, the concentration sensor 13 in the abnormality detection device provided in the embodiment of the present application is arranged in the airway space 1021 or in the airway space 1022. The electrolyte vapor in the internal space of the lithium battery 1 can diffuse along the airway space 102 to the concentration sensor, so that the electrolyte vapor concentration can be detected more accurately and timely.

[0061] When the abnormality detection device includes one concentration sensor 13, the one concentration sensor 13 is disposed in the airway space 1021 or in the middle of the airway space 1022. When the abnormality detection device includes multiple concentration sensors 13, the multiple concentration sensors 13 can be evenly spaced in the airway space, and the multiple concentration sensors 13 can be combined into one group and connected to the controller 14 together.

[0062] The concentration sensor 13 can be fixed to the tray 11 by means of bolts, or can be adhered to the tray by means of high-strength glue, or can also be fixed in other ways.

[0063] The concentration sensor 13 is connected to the controller 14 via a wiring harness 15, and the controller 14 is connected to the BMS 16 via the wiring harness 15. The wiring harness 15 provides connection modes including: a single bus, a serial peripheral interface (SPI), an integrated circuit bus (I2C), and the like.

[0064] The abnormality detection device for the lithium battery 1 provided in this embodiment has a relatively simple structure and low cost, which is conducive to the application and promotion of the abnormality detection device.

[0065] In another embodiment, the controller 14 and the BMS 16 may be independent devices, in which case the controller 14 may be an MCU, and the communication connection between the controller 14 and the BMS 16 includes but is not limited to a single bus, SPI, I2C, a universal asynchronous receiver / transmitter (UART), etc. Alternatively, the BMS 16 may provide an MCU as the controller 14, in which case the controller 14 is equivalent to being integrated into the BMS 16.

[0066] Figure 7 This is a schematic diagram of the external structure of an embodiment of a concentration sensor provided by the present application. Figure 8 This is a schematic diagram of the internal structure of an embodiment of a concentration sensor provided in this application, combined with Figure 7 and Figure 8 The concentration sensor 13 provided in this embodiment includes: a concentration sensor chip 134, a microcontroller unit (MCU) 135, a housing 131, a circuit board 133 and a connecting line 136. The circuit board 133 is arranged in the inner space of the housing 131, and the housing 131 is also provided with at least one air hole 132, through which the electrolyte vapor can enter the interior of the housing 131. When the electrolyte solvent vapor contacts the concentration sensor chip 134, the circuit parameters of the concentration sensor 134 change. One end of the connecting line 136 is connected to the MCU135, and the other end extends out of the housing 131 through the opening of the connecting line, and extends along the airway space 1021 and connects to the controller 14. The MCU135 generates a signal according to the change of the circuit parameter and sends it to the controller 14 through the connecting line 136.

[0067] In the aforementioned embodiments of the present application, the abnormality detection method of the lithium battery provided in the embodiments of the present application is introduced, and in order to realize the various functions in the method provided in the above embodiments of the present application, the controller 14 as the execution subject may include a hardware structure and / or a software module, and realize the above functions in the form of a hardware structure, a software module, or a hardware structure plus a software module. Whether one of the above functions is executed in the form of a hardware structure, a software module, or a hardware structure plus a software module depends on the specific application and design constraints of the technical solution.

[0068] For example, Fig. 9 A schematic diagram of the structure of a lithium battery abnormality detection device provided in this application, such as Fig. 9 The device shown can be used to perform the abnormality detection method of the lithium battery provided in any of the above embodiments of the present application. In one embodiment, Fig. 9 The abnormality detection device 1000 of a lithium battery shown includes: an acquisition module 1001, a processing module 1002 and a determination module 1003. The acquisition module 1001 is used to acquire the first electrolyte vapor concentration of the internal space of the lithium battery at the first moment; the processing module 1002 is used to determine the change of the electrolyte vapor concentration of the internal space of the lithium battery at the first moment according to the first electrolyte vapor concentration and the second electrolyte vapor concentration at the second moment before the first moment; the determination module 1003 is used to determine whether the lithium battery is abnormal according to the first electrolyte vapor concentration and the change of the electrolyte vapor concentration.

[0069] The specific implementation method and principle of the above-mentioned lithium battery abnormality detection device refer to the description of the above-mentioned lithium battery abnormality detection method, which will not be repeated here.

[0070] It should be noted that it should be understood that the division of the various modules of the above device is only a division of logical functions. In actual implementation, they can be fully or partially integrated into one physical entity, or they can be physically separated. And these modules can all be implemented in the form of software called by processing elements; they can also be all implemented in the form of hardware; some modules can also be implemented in the form of software called by processing elements, and some modules can be implemented in the form of hardware. For example, the processing module can be a separately established processing element, or it can be integrated in a chip of the above device. In addition, it can also be stored in the memory of the above device in the form of program code, and called and executed by a processing element of the above device. The function of the above-mentioned module is determined. The implementation of other modules is similar. In addition, these modules can be fully or partially integrated together, or they can be implemented independently. The processing element described here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each module above can be completed by an integrated logic circuit of hardware in the processor element or instructions in the form of software.

[0071] For example, the above modules may be one or more integrated circuits configured to implement the above methods, such as one or more application specific integrated circuits (ASIC), or one or more microprocessors (digital signal processors, DSP), or one or more field programmable gate arrays (FPGA), etc. For another example, when a module above is implemented in the form of a processing element scheduling program code, the processing element may be a general-purpose processor, such as a central processing unit (CPU) or other processor that can call program code. For another example, these modules may be integrated together and implemented in the form of a system-on-a-chip (SOC).

[0072] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid state disk (SSD)), etc.

[0073] For example, Fig.10 A schematic diagram of the structure of a lithium battery abnormality detection device provided in this application, such as Fig.10 The device shown can be used to perform the abnormality detection method of the lithium battery provided in any embodiment of the present application. In one embodiment, Fig.10 The lithium battery abnormality detection device 2000 shown includes a processor 2001 and a memory 2002; wherein the memory 2002 is used to store computer executable instructions, and the processor 2001 can execute the computer executable instructions stored in the memory 2002. When the computer executable instructions are executed by the processor 2001, the processor 2001 implements any lithium battery abnormality detection method in the aforementioned embodiments of the present application.

[0074] In one embodiment, if Fig.10 The lithium battery abnormality detection device 2000 shown also includes a communication interface 2003 , wherein the processor 2001 can communicate with other devices through the communication interface 2003 , for example, the processor 2001 obtains the first electrolyte vapor concentration through the communication interface 2003 .

[0075] The present application also provides a battery system, including a lithium battery and an abnormality detection device for the lithium battery 1 as provided in any of the aforementioned embodiments of the present application, wherein the abnormality detection device for the lithium battery 1 is used to detect whether the lithium battery 1 is abnormal.

[0076] The present application also provides an electric vehicle, including the above-mentioned battery system, wherein the battery system includes a lithium battery and an abnormality detection device for the lithium battery 1 as provided in any of the above-mentioned embodiments of the present application.

[0077] The present application also provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are executed, they can be used to implement any lithium battery abnormality detection method as described in the aforementioned embodiments of the present application.

[0078] An embodiment of the present application also provides a chip for executing instructions, wherein the chip is used to execute any of the lithium battery abnormality detection methods described above in the present application.

[0079] An embodiment of the present application also provides a computer program product, including a computer program, which, when executed, implements any of the lithium battery abnormality detection methods described above in the present application.

[0080] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for detecting abnormality of a lithium battery, characterized in that: include: Obtaining a first electrolyte vapor concentration in the internal space of the lithium battery (1) at a first moment; Determining a change in electrolyte vapor concentration in the internal space of the lithium battery (1) based on the first electrolyte vapor concentration and the second electrolyte vapor concentration at a second moment before the first moment; Whether the lithium battery (1) is abnormal is determined based on the first electrolyte vapor concentration and the change in the electrolyte vapor concentration.

2. The method according to claim 1, characterized in that Determining whether the lithium battery (1) is abnormal according to the first electrolyte vapor concentration and the change in the electrolyte vapor concentration includes: When the increasing speed of the electrolyte vapor concentration is less than a second preset speed value, determining whether the lithium battery (1) has leakage abnormality according to the increasing speed and the first electrolyte vapor concentration; When the rate of increase of the electrolyte vapor concentration is greater than or equal to the second preset rate value, it is determined whether the lithium battery (1) has a thermal runaway anomaly based on the first electrolyte vapor concentration.

3. The method according to claim 2, characterized in that When the increasing speed of the electrolyte vapor concentration is less than a second preset speed value, determining whether the lithium battery (1) has leakage abnormality according to the increasing speed and the first electrolyte vapor concentration includes: When the increasing speed is less than the second speed preset value, the increasing speed is greater than or equal to the first speed preset value, and the first electrolyte vapor concentration is greater than or equal to the first concentration preset value, it is determined that the lithium battery (1) has leakage abnormality.

4. The method according to claim 2, characterized in that: When the rate of increase of the electrolyte vapor concentration is greater than or equal to the second rate preset value, determining whether the lithium battery (1) has a thermal runaway abnormality according to the first electrolyte vapor concentration comprises: When the increasing speed is greater than or equal to the second speed preset value, and the first electrolyte vapor concentration is greater than or equal to the second concentration preset value, it is determined that the lithium battery (1) has a thermal runaway anomaly.

5. The method according to any one of claims 2 to 4, characterized in that: After determining whether the lithium battery (1) is abnormal based on the first electrolyte vapor concentration and the electrolyte vapor concentration change, the method further includes: When it is determined that the lithium battery (1) has an abnormality, abnormality information of the lithium battery (1) is output.

6. The method according to any one of claims 2 to 5, characterized in that: The method of determining whether the lithium battery (1) is abnormal based on the first electrolyte vapor concentration and the change in the electrolyte vapor concentration further includes: When the concentration increase rate is less than a first preset rate value, and the first electrolyte vapor concentration is less than a first preset concentration value, it is determined that the lithium battery (1) has no abnormality.

7. The method according to any one of claims 2 to 6, characterized in that: The method of determining whether the lithium battery (1) is abnormal based on the first electrolyte vapor concentration and the change in the electrolyte vapor concentration further includes: When the first electrolyte vapor concentration is less than the second concentration preset value, the first electrolyte vapor concentration is greater than or equal to the first concentration preset value, and the increase rate is greater than or equal to the second preset value, it is determined that the lithium battery (1) has a thermal runaway abnormality risk; When the increase rate is greater than or equal to the first preset rate value, and the first electrolyte vapor concentration is less than the first preset concentration value, it is determined that the lithium battery (1) has a risk of abnormal leakage; When the increasing speed is less than the first speed preset value, and the first electrolyte vapor concentration is greater than or equal to the first concentration preset value, it is determined that the lithium battery (1) has a risk of abnormal leakage.

8. The method according to claim 7, characterized in that After determining whether the lithium battery (1) is abnormal based on the first electrolyte vapor concentration and the electrolyte vapor concentration change, the method further includes: When it is determined that the lithium battery (1) has an abnormal risk, abnormal risk information of the lithium battery (1) is output.

9. A lithium battery abnormality detection device, characterized in that: include: A controller (14) and at least one concentration sensor (13), wherein the controller (14) is connected to the at least one concentration sensor (13), and the at least one concentration sensor (13) is arranged in a battery pack of the lithium battery (1) and is used to detect the concentration of electrolyte gas in the battery pack and send it to the controller (14); The controller (14) is configured to execute the method according to any one of claims 1-8.

10. The device according to claim 9, characterized in that The battery pack of the lithium battery (1) comprises a tray (11), an upper cover plate (12) and at least one battery cell (10), wherein the at least one battery cell (10) is arranged in parallel in a space between the tray (11) and the upper cover plate (12); An air passage space (102) is formed between one end of the at least one battery cell (10) and the side wall of the tray (11), and the at least one concentration sensor (13) is arranged in the air passage space (102).

11. The device according to claim 10, characterized in that The concentration sensor (13) comprises: A concentration sensor chip (134), a microprocessing unit (135), a housing (131), a circuit board (133) and a connecting wire (136); the concentration sensor chip (134) and the microprocessing unit (135) are arranged on the circuit board (133); the circuit board (133) is arranged in the housing (131); a connecting wire opening and at least one air hole (132) are arranged on the housing (131); one end of the connecting wire (136) is connected to the microprocessing unit (135); the other end of the connecting wire protrudes from the housing (131) through the connecting wire opening, extends along the airway space and is connected to the controller (14).

12. A battery system, characterized in that: include: A lithium battery (1) and a lithium battery abnormality detection device as claimed in any one of claims 9 to 11, wherein the lithium battery abnormality detection device is used to detect whether the lithium battery (1) is abnormal.

13. An electric vehicle, characterized in that: Comprising the battery system as claimed in claim 12.

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