A battery lithium deposition detection method, device and related equipment

Abstract

The present application discloses a battery lithium plating detection method, device and related equipment, the method comprising: obtaining the battery pressure change value per unit charge at the detection point during the charging process of the electric vehicle in a preset cycle; judging whether the battery pressure change value is greater than a reference value, and if so, determining that one lithium plating has occurred at the detection point; wherein the reference value is the battery pressure change value per unit charge detected when the electric vehicle reaches a preset state of charge in the most recent charge. The present application does not require changing the structure of the battery itself, and implements lithium plating detection in a non-destructive manner, and has a high sensitivity for lithium plating detection, and can be integrated into the battery management system on the vehicle side to ensure the safe operation of the vehicle.

Description

Technical Field

[0001] The present application relates to the technical field of lithium batteries, and more specifically, to a battery lithium deposition detection method, device and related equipment. Background Art

[0002] With the booming development of the new energy market, the safety of new energy vehicles has received increasing attention. Among them, the safety of new energy vehicles mainly focuses on battery cell safety. Among battery cell safety, lithium plating in the battery cell is an important cause that may cause thermal runaway of the battery cell and cannot be ignored. Specifically, lithium plating in the battery cell will lead to a decrease in thermal stability. When the lithium dendrites caused by lithium plating pierce the diaphragm and cause an internal short circuit, it may cause irreversible thermal safety events. Therefore, it is very necessary to detect lithium plating in advance during vehicle operation, take countermeasures in advance, and avoid serious safety incidents. Summary of the invention

[0003] In view of this, the present application provides a battery lithium deposition detection method, device and related equipment to achieve lithium deposition detection.

[0004] To achieve the above objectives, the present application provides a first aspect of a battery lithium deposition detection method, comprising:

[0005] At a preset period, based on a differential pressure sensing strategy, a battery pressure change value per unit charge at a detection point during the charging process of an electric vehicle is obtained;

[0006] Determine whether the detection time of the reference value exceeds a preset time interval from the current time, and if so, remind the user to perform a deep charge and deep discharge operation; wherein the reference value is the battery pressure change value per unit charge detected based on the differential pressure sensing strategy when the electric vehicle reaches a preset state of charge in the most recent charge;

[0007] Determine whether the battery pressure change value is greater than the reference value, and if so, determine that lithium deposition occurs once at the detection point;

[0008] Determine whether the cumulative number of lithium plating times of the detection point reaches a preset number, and if so, send an alarm message to the background.

[0009] Preferably, the preset time interval is 30 days.

[0010] Preferably, after obtaining the battery pressure change value per unit charge at the detection point during the charging process of the electric vehicle based on the differential pressure sensing strategy, the method further includes:

[0011] The battery pressure change value is uploaded to the background database, and the database is used for real-time monitoring of the entire life cycle of the battery pack.

[0012] Preferably, the detection point is arranged between adjacent single cells in the battery pack;

[0013] Alternatively, the detection point is arranged between adjacent strings of battery cells in the battery pack.

[0014] Preferably, the preset state of charge is 10% charge.

[0015] The second aspect of the present application provides a battery lithium deposition detection device, comprising:

[0016] A sensing unit, used to obtain a battery pressure change value per unit charge at a detection point during the charging process of the electric vehicle based on a differential pressure sensing strategy at a preset period;

[0017] A calibration unit is used to determine whether the detection time of the reference value exceeds a preset time interval from the current time, and if so, remind the user to perform a deep charge and deep discharge operation; wherein the reference value is the battery pressure change value per unit charge detected based on the differential pressure sensing strategy when the electric vehicle reaches a preset state of charge in the most recent charge; a comparison unit is used to determine whether the battery pressure change value is greater than the reference value, and if so, determine that one lithium deposition occurs at the detection point;

[0018] The alarm unit is used to determine whether the cumulative number of lithium plating times at the detection point has reached a preset number, and if so, send an alarm message to the background.

[0019] A third aspect of the present application provides a battery lithium deposition detection device, comprising: a memory and a processor;

[0020] The memory is used to store programs;

[0021] The processor is used to execute the program to implement each step of the above-mentioned battery lithium deposition detection method.

[0022] A fourth aspect of the present application provides a storage medium on which a computer program is stored. When the computer program is executed by a processor, the various steps of the battery lithium deposition detection method as described above are implemented.

[0023] It can be known from the above technical solution that the present application obtains a reference value in advance, wherein the reference value is the battery pressure change value per unit charge detected based on the differential pressure sensing strategy when the electric vehicle reaches a preset state of charge in the most recent charge. It can be understood that the reference value represents the maximum value of lithium ion embedding allowed during the battery charging process to a certain extent. Then, the battery pressure change value per unit charge of the detection point during the charging process of the electric vehicle is obtained based on the differential pressure sensing strategy at a preset cycle. For the battery pressure change value detected in real time in each cycle, it is determined whether the battery pressure change value is greater than the reference value. If so, it is determined that lithium plating occurs once at the detection point. The present application does not need to change the structure of the battery itself, realizes lithium plating detection in a non-destructive manner, and has a high sensitivity for lithium plating detection. It can be integrated into the battery management system on the vehicle side to ensure the safe operation of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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 embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of a battery lithium deposition detection method disclosed in an embodiment of the present application;

[0026] Figure 2 Another schematic diagram of the battery lithium deposition detection method disclosed in the embodiment of the present application;

[0027] Figure 3 Another schematic diagram of the battery lithium deposition detection method disclosed in the embodiment of the present application;

[0028] Figure 4 A schematic diagram of a battery lithium deposition detection device disclosed in an embodiment of the present application;

[0029] Figure 5 This is a schematic diagram of a battery lithium deposition detection device disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0030] 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.

[0031] The following describes the battery lithium deposition detection method provided by the embodiment of the present application. Figure 1 The battery lithium deposition detection method provided in the embodiment of the present application may include the following steps:

[0032] Step S101, obtaining the battery pressure change value per unit charge at the detection point during the charging process of the electric vehicle at a preset period.

[0033] Among them, the battery pressure change value per unit charge can be expressed as dP / dQ. Based on the differential pressure sensing strategy (Differential Pressure Sensing, proposed by Professor Cui Yi and Li Yuzhang of Stanford University in the United States), the pressure value can be detected by a pressure sensor, and the battery management system (Battery Management System, BMS) can be used for differential calculation to finally obtain dP / dQ.

[0034] It should be noted that BMS is the controller of the high-voltage power battery, which is used to detect the status of various components inside the high-voltage power battery, including battery cell voltage, module voltage, total battery voltage, current, temperature, battery insulation, cell stress and other parameters; it is also used to control and coordinate various tasks of the internal components of the high-voltage power battery. Specifically, BMS can include a BMS main board and a BMS slave board, wherein the BMS main board is used to collect the total battery voltage, insulation detection, etc., and is responsible for processing the single cell voltage, temperature and dP / dQ collected by the slave board. The BMS slave board is responsible for collecting battery cell voltage, temperature, stress (P), etc., and is also used to judge the validity of the signal, the battery balancing function, etc.

[0035] Step S102, determining whether the battery pressure change value is greater than a reference value. If so, executing step S103.

[0036] The reference value is the battery pressure change per unit charge detected by the differential pressure sensing strategy when the electric vehicle reaches a preset state of charge (SOC) in the most recent charge. This value can be used as the maximum value of lithium ion insertion in this charge, recorded as (dP / dQ) max It should be noted that it is necessary to charge and discharge a new car before it leaves the factory and obtain the reference value for the first time. max Affected by factors such as temperature and battery aging, when the next charge reaches the preset state of charge, it is necessary to re-perform (dP / dQ) max Calibration.

[0037] Step S103, determining that lithium deposition occurs once at the detection point.

[0038] After each lithium deposition is diagnosed, the BMS can store and manage the number of lithium deposition events for subsequent follow-up processing.

[0039] The present application obtains a reference value in advance, wherein the reference value is the battery pressure change value per unit charge detected based on the differential pressure sensing strategy when the electric vehicle reaches a preset state of charge in the most recent charge. It can be understood that the reference value represents the maximum value of lithium ion embedding allowed during the battery charging process to a certain extent. Then, the battery pressure change value per unit charge of the detection point during the charging process of the electric vehicle is obtained based on the differential pressure sensing strategy at a preset cycle. For the battery pressure change value detected in real time in each cycle, it is determined whether the battery pressure change value is greater than the reference value. If so, it is determined that one lithium plating occurs at the detection point. The present application does not need to change the structure of the battery itself, realizes lithium plating detection in a non-destructive manner, and has a high sensitivity for lithium plating detection. It can be integrated into the battery management system on the vehicle side to ensure the safe operation of the vehicle.

[0040] In some embodiments of the present application, the detection point mentioned in step S101 may be set between adjacent single battery cells in the battery pack; or, the detection point may also be set between adjacent strings of battery cells in the battery pack.

[0041] A battery pack is assembled from multiple modules, and the modules are assembled from multiple cells. Based on this, for example, a flexible film sensor (i.e., a detection point) can be set between the cells to collect relevant signals. The flexible sensor can be set between adjacent single cells in the battery pack, and can be set between adjacent strings of cells in the battery pack. It can be understood that the signal acquisition can be integrated in the BMS.

[0042] In some embodiments of the present application, Figure 2 As shown, after determining in step S103 that lithium deposition occurs once at the detection point, the method may further include:

[0043] Step S104, determining whether the cumulative number of lithium depositions at the detection point reaches a preset number. If yes, executing step S105.

[0044] Exemplarily, the number of times may be preset to 3.

[0045] Step S105: Send warning information to the background.

[0046] By sending warning information to the backend, it is convenient for relevant professionals to handle the vehicle to reduce the operating risk of the vehicle. Among them, the backend is generally arranged in the data monitoring center of the car company, which receives data uploaded by the telematics system (TEL) and interacts with the customer's mobile phone APP. It can be used for data analysis, storage, and sending and receiving instructions with the customer's mobile phone APP; at the same time, it can also contact the vehicle rescue team and the emergency accident team to deal with vehicle failures and other matters.

[0047] In addition to sending warning information to the background, the warning information can also be directly displayed in the instrument cluster module (ICM) in the vehicle passenger compartment to show the driver the vehicle status in a timely manner.

[0048] In some embodiments of the present application, the state of charge mentioned in step S102 is 10% SOC.

[0049] In some embodiments of the present application, Figure 3 As shown, before determining whether the battery pressure change value is greater than the reference value in step S102, the following steps may also be included:

[0050] Step S106, determining whether the detection time of the reference value exceeds a preset time interval from the current time. If so, executing step S107.

[0051] Step S107, reminding the user to perform a deep charge and deep discharge operation.

[0052] Due to (dP / dQ) max Affected by factors such as temperature and battery aging, the reference value needs to be updated in a timely manner to ensure the effectiveness of lithium plating detection.

[0053] In some embodiments of the present application, the time interval mentioned in step S106 may be 30 days. It is understood that the BMS will automatically obtain the reference value when the vehicle is charging. However, if the vehicle is not charged after deep discharge, that is, the state of charge cannot reach the preset state of charge (such as 10% SOC) from a lower value, the charging scenario for obtaining the reference value cannot be met. If there is no suitable charging scenario for 1 consecutive month, the user will be reminded to deep charge and deep discharge once.

[0054] In some embodiments of the present application, after obtaining the battery pressure change value per unit charge at the detection point during the charging process of the electric vehicle in step S101, the following may also be included:

[0055] Step S108, uploading the battery pressure change value to a background database.

[0056] For example, the battery pressure change value can be uploaded to the background database via TEL. The database is used for real-time monitoring of the battery pack throughout its life cycle. If an abnormal point occurs during the life cycle, the vehicle needs to be processed in a timely manner.

[0057] The battery lithium deposition detection device provided in an embodiment of the present application is described below. The battery lithium deposition detection device described below and the battery lithium deposition detection method described above can be referenced to each other.

[0058] See also Figure 4 The battery lithium deposition detection device provided in the embodiment of the present application may include:

[0059] The sensing unit 21 is used to obtain the battery pressure change value per unit charge at the detection point during the charging process of the electric vehicle based on the differential pressure sensing strategy at a preset period;

[0060] A comparison unit 22, used to determine whether the battery pressure change value is greater than a reference value, and if so, determine that one lithium deposition occurs at the detection point;

[0061] The reference value is a battery pressure change value per unit charge detected based on a differential pressure sensing strategy when the electric vehicle reaches a preset state of charge in the most recent charge.

[0062] In some embodiments of the present application, the battery lithium deposition detection device may further include an alarm unit, which is used to:

[0063] After determining that lithium deposition occurs once at the detection point, determining whether the cumulative number of lithium depositions at the detection point reaches a preset number;

[0064] If so, send an alarm message to the background.

[0065] In some embodiments of the present application, the battery lithium deposition detection device may further include a reminder unit, and the calibration unit is used to:

[0066] Before determining whether the battery pressure change value is greater than a reference value, determining whether the detection time of the reference value exceeds a preset time interval from the current time;

[0067] If so, remind the user to perform a deep charge and discharge operation.

[0068] In some embodiments of the present application, the battery lithium deposition detection device may further include an uploading unit, and the uploading unit is used to:

[0069] After obtaining the battery pressure change value per unit charge at the detection point during the charging process of the electric vehicle based on the differential pressure sensing strategy, the battery pressure change value is uploaded to the background database, which is used for real-time monitoring of the entire life cycle of the battery pack.

[0070] The battery lithium deposition detection device provided in the embodiment of the present application can be applied to battery lithium deposition detection equipment, such as a computer, etc. Optionally, Figure 5 The hardware structure diagram of the battery lithium deposition detection equipment is shown in FIG. Figure 5 The hardware structure of the battery lithium deposition detection device may include: at least one processor 31, at least one communication interface 32, at least one memory 33 and at least one communication bus 34.

[0071] In the embodiment of the present application, the number of the processor 31, the communication interface 32, the memory 33, and the communication bus 34 is at least one, and the processor 31, the communication interface 32, and the memory 33 communicate with each other through the communication bus 34;

[0072] The processor 31 may be a central processing unit CPU, or an application-specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present application, etc.;

[0073] The memory 33 may include a high-speed RAM memory, and may also include a non-volatile memory, such as at least one disk memory;

[0074] The memory 33 stores a program, and the processor 31 can call the program stored in the memory 33, and the program is used to:

[0075] At a preset period, based on a differential pressure sensing strategy, a battery pressure change value per unit charge at a detection point during the charging process of an electric vehicle is obtained;

[0076] Determine whether the battery pressure change value is greater than a reference value, and if so, determine that lithium deposition occurs once at the detection point;

[0077] The reference value is a battery pressure change value per unit charge detected based on a differential pressure sensing strategy when the electric vehicle reaches a preset state of charge in the most recent charge.

[0078] Optionally, the detailed functions and extended functions of the program may refer to the above description.

[0079] The embodiment of the present application further provides a storage medium, which may store a program suitable for execution by a processor, wherein the program is used to:

[0080] At a preset period, based on a differential pressure sensing strategy, a battery pressure change value per unit charge at a detection point during the charging process of an electric vehicle is obtained;

[0081] Determine whether the battery pressure change value is greater than a reference value, and if so, determine that lithium deposition occurs once at the detection point;

[0082] The reference value is a battery pressure change value per unit charge detected based on a differential pressure sensing strategy when the electric vehicle reaches a preset state of charge in the most recent charge.

[0083] Optionally, the detailed functions and extended functions of the program may refer to the above description.

[0084] In summary:

[0085] The present application obtains a reference value in advance, wherein the reference value is the battery pressure change value per unit charge detected based on the differential pressure sensing strategy when the electric vehicle reaches a preset state of charge in the most recent charge. It can be understood that the reference value represents the maximum value of lithium ion embedding allowed during the battery charging process to a certain extent. Then, the battery pressure change value per unit charge of the detection point during the charging process of the electric vehicle is obtained based on the differential pressure sensing strategy at a preset cycle. For the battery pressure change value detected in real time in each cycle, it is determined whether the battery pressure change value is greater than the reference value. If so, it is determined that one lithium plating occurs at the detection point. The present application does not need to change the structure of the battery itself, realizes lithium plating detection in a non-destructive manner, and has a high sensitivity for lithium plating detection. It can be integrated into the battery management system on the vehicle side to ensure the safe operation of the vehicle.

[0086] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0087] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can refer to each other.

[0088] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery lithium deposition detection method, characterized in that: include: At a preset period, based on a differential pressure sensing strategy, a battery pressure change value per unit charge at a detection point during the charging process of an electric vehicle is obtained; Determine whether the detection time of the reference value exceeds a preset time interval from the current time, and if so, remind the user to perform a deep charge and deep discharge operation; wherein the reference value is the battery pressure change value per unit charge detected based on the differential pressure sensing strategy when the electric vehicle reaches a preset state of charge in the most recent charge; Determine whether the battery pressure change value is greater than the reference value, and if so, determine that lithium deposition occurs once at the detection point; Determine whether the cumulative number of lithium depositions at the detection point reaches a preset number, and if so, send an alarm message to the background; The preset state of charge is 10% charge.

2. The method according to claim 1, characterized in that The preset time interval is 30 days.

3. The method according to claim 1, characterized in that After obtaining the battery pressure change value per unit charge at the detection point during the charging process of the electric vehicle based on the differential pressure sensing strategy, it also includes: The battery pressure change value is uploaded to the background database, and the database is used for real-time monitoring of the entire life cycle of the battery pack.

4. The method according to claim 1, characterized in that: The detection point is arranged between adjacent single cells in the battery pack; Alternatively, the detection point is arranged between adjacent strings of battery cells in the battery pack.

5. A battery lithium deposition detection device for realizing the battery lithium deposition detection method according to any one of claims 1 to 4, characterized in that: include: A sensing unit, used to obtain a battery pressure change value per unit charge at a detection point during the charging process of the electric vehicle based on a differential pressure sensing strategy at a preset period; A calibration unit is used to determine whether the detection time of the reference value exceeds a preset time interval from the current time, and if so, remind the user to perform a deep charge and deep discharge operation; wherein the reference value is the battery pressure change value per unit charge detected based on the differential pressure sensing strategy when the electric vehicle reaches a preset state of charge in the most recent charge; a comparison unit is used to determine whether the battery pressure change value is greater than the reference value, and if so, determine that one lithium deposition occurs at the detection point; The alarm unit is used to determine whether the cumulative number of lithium plating times at the detection point has reached a preset number, and if so, send an alarm message to the background.

6. A battery lithium deposition detection device, characterized in that: include: Memory and processor; The memory is used to store programs; The processor is used to execute the program to implement each step of the battery lithium deposition detection method as described in any one of claims 1 to 4.

7. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, each step of the battery lithium deposition detection method as described in any one of claims 1 to 4 is implemented.

Images