Self-heating control method and system for charge / discharge battery

Abstract

A method and a system for controlling self-heating of a rechargeable / dischargeable battery are disclosed. The rechargeable / dischargeable battery includes a cell (40), a separator (43) is provided between a positive electrode (41) and a negative electrode (42) of the cell (40), a reference electrode (10) is provided corresponding to the separator (43), and a surface electrode (20) is provided corresponding to the surface of the negative electrode (42) of the cell (40). The method for controlling self-heating of the battery includes the steps of detecting a potential difference between the reference electrode (10) and the surface electrode (20), and generating a charge current adjustment command based on the potential difference between the reference electrode (10) and the surface electrode (20), thereby adjusting a charge current of the rechargeable / dischargeable battery based on the charge current adjustment command during the self-heating process of the rechargeable / dischargeable battery.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This disclosure claims priority to Chinese Patent Application No. 202111074668.7, entitled "Method and system for controlling self-heating of charge-discharge batteries," filed on September 14, 2021, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to the field of batteries, and in particular to a method for controlling self-heating of a chargeable / dischargeable battery, a computer-readable storage medium, a battery management device, and a system for controlling self-heating of a chargeable / dischargeable battery. [Background technology]

[0003] Batteries are currently the most widely used energy storage devices in the field of new energy vehicles. The charge and discharge capacity of batteries is significantly affected by temperature. By applying energy from the battery itself or from an external source to a single cell to heat the battery, the discharge capacity of the battery at low temperatures can be effectively improved, thereby increasing the driving range.

[0004] In the related art, the self-heating method of the battery causes serious uneven heating of the battery, and when charging with a large current, the uneven temperature of the cell causes lithium deposition in some areas of the battery, affecting the cycle life and safety of the battery. Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure aims to solve at least one of the technical problems in the related art, and therefore, one object of the present disclosure is to provide a self-heating control method for a charge-discharge battery that can uniformly heat the battery, prevent lithium deposition in the battery, and improve the cycle life and safety of the battery. [Means for solving the problem]

[0006] The present disclosure further provides a computer-readable storage medium.

[0007] The present disclosure further provides a battery management device.

[0008] The present disclosure further provides a self-heating control system for a charge / discharge battery.

[0009] In the self-heating control method for a charge-discharge battery according to the present disclosure, the charge-discharge battery includes a cell, a separator provided between a positive electrode and a negative electrode of the cell, a reference electrode provided corresponding to the separator, and a surface electrode provided corresponding to the surface of the negative electrode of the cell, and the method includes the steps of detecting a potential difference between the reference electrode and the surface electrode, and generating a charge current adjustment command based on the potential difference between the reference electrode and the surface electrode, thereby adjusting the charge current of the charge-discharge battery based on the charge current adjustment command during the self-heating process of the charge-discharge battery.

[0010] According to the self-heating control method for a charge-discharge battery disclosed herein, the potential difference between the reference electrode and the surface electrode is detected, and a charge current adjustment command is generated based on the potential difference between the reference electrode and the surface electrode. By adjusting the charge current of the charge-discharge battery based on the charge current adjustment command during the self-heating process of the charge-discharge battery, it is possible to avoid the occurrence of lithium precipitation in the battery and improve the cycle life and safety of the battery.

[0011] In some examples of the present disclosure, generating a charging current adjustment command based on the potential difference between the reference electrode and the surface electrode includes generating a charging current adjustment command with a charging current amplitude value of zero when the potential difference between the reference electrode and the surface electrode is less than a first potential threshold, and generating a charging current adjustment command based on the first potential threshold and the potential difference between the reference electrode and the surface electrode when the potential difference between the reference electrode and the surface electrode is greater than or equal to the first potential threshold and less than a second potential threshold.

[0012] In some examples of the present disclosure, when the potential difference between the reference electrode and the surface electrode is greater than or equal to a first potential threshold and less than a second potential threshold, Determine a charging current amplitude value corresponding to the charging current adjustment command according to the formula: I_dc=I_dc0*f(s1)*(VN-E_plating); where s1 is the first safety parameter, f(s1) is a function of s1, I_dc is the charging current amplitude value, I_dc0 is the initial charging current amplitude value, VN is the potential difference between the reference electrode and the surface electrode, and E_plating is the first potential threshold.

[0013] In some examples of the present disclosure, the first potential threshold is determined based on the steps of detecting a potential difference between the negative electrode of the cell and a reference electrode, obtaining negative electrode potential curves at different charge rates based on the potential difference between the negative electrode of the cell and the reference electrode, obtaining a relationship between lithium deposition potential and charge rate based on the negative electrode potential curves at different charge rates, and determining the first potential threshold based on the relationship between lithium deposition potential and charge rate.

[0014] In some examples of the present disclosure, if the potential difference between the reference electrode and the surface electrode is less than a first potential threshold, the method further includes detecting the potential difference between the positive electrode of the cell and the reference electrode, and generating a battery heating current adjustment command based on the potential difference between the positive electrode of the cell and the reference electrode, thereby adjusting the heating current amplitude value of the charging / discharging battery based on the battery heating current adjustment command during the self-heating process of the charging / discharging battery.

[0015] In some examples of the present disclosure, generating a battery heating current adjustment command based on the potential difference between the positive electrode of the cell and the reference electrode includes generating a battery heating current adjustment command with a heating current amplitude value of zero when the potential difference between the positive electrode of the cell and the reference electrode is greater than a third potential threshold, and generating a battery heating current adjustment command based on the third potential threshold and the potential difference between the positive electrode of the cell and the reference electrode when the potential difference between the positive electrode of the cell and the reference electrode is greater than a fourth potential threshold and less than or equal to the third potential threshold.

[0016] In some examples of the present disclosure, when the potential difference between the positive electrode and the reference electrode of the cell is greater than a fourth potential threshold and less than or equal to a third potential threshold: Determine a heating current amplitude value corresponding to the battery heating current adjustment command according to the formula: I_ac=I_ac0*f(s2)*(VP-E_max); where s2 is the second safety parameter, f(s2) is a function of s2, I_ac is the heating current amplitude value, I_ac0 is the initial heating current amplitude value, VP is the potential difference between the positive electrode and the reference electrode of the cell, and E_max is the third potential threshold.

[0017] A computer-readable storage medium according to the present disclosure stores a self-heating control program for a chargeable / dischargeable battery that, when executed by a processor, realizes the self-heating control method for a chargeable / dischargeable battery.

[0018] According to the computer-readable storage medium of the present disclosure, the potential difference between the reference electrode and the surface electrode is detected, and a charge current adjustment command is generated based on the potential difference between the reference electrode and the surface electrode. By adjusting the charge current of the charge-discharge battery based on the charge current adjustment command during the self-heating process of the charge-discharge battery, the battery can be heated uniformly, lithium precipitation in the battery can be avoided, and the cycle life and safety of the battery can be improved.

[0019] The battery management device of the present disclosure includes a memory, a processor, and a self-heating control program for a chargeable / dischargeable battery that is stored in the memory and executable by the processor, and when the processor executes the self-heating control program for a chargeable / dischargeable battery, the above-mentioned self-heating control method for a chargeable / dischargeable battery is realized.

[0020] The battery management device according to the present disclosure can uniformly heat the battery, prevent lithium deposition in the battery, and improve the cycle life and safety of the battery.

[0021] The self-heating control system for a charge / discharge battery according to the present disclosure includes a reference electrode, a surface electrode, and a battery management device, wherein the reference electrode is provided corresponding to a separator between the positive electrode and the negative electrode of a cell in the charge / discharge battery, and the surface electrode is provided corresponding to the surface of the negative electrode of the cell, and the battery management device is connected to the reference electrode and the surface electrode, respectively, detects a potential difference between the reference electrode and the surface electrode, and generates a charge current adjustment command based on the potential difference between the reference electrode and the surface electrode, thereby adjusting the charge current of the charge / discharge battery based on the charge current adjustment command during the self-heating process of the charge / discharge battery.

[0022] The self-heating control system for a charge / discharge battery according to the present disclosure can uniformly heat the battery, prevent lithium deposition in the battery, and improve the cycle life and safety of the battery.

[0023] In some examples of the present disclosure, the reference electrode is electronically isolated but ionically conductive with the positive and negative electrodes of the cell, and the surface electrode is in direct contact and electronically conductive with the negative electrode of the cell.

[0024] Additional aspects and advantages of the disclosure will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the disclosure. [Brief explanation of the drawings]

[0025] The above and / or additional aspects and advantages of the present disclosure will become more apparent and easier to understand by describing examples with reference to the following drawings.

[0026] [Figure 1] 1 is a flowchart of a self-heating control method according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a cross-sectional view of a cell according to an embodiment of the present disclosure. [Figure 3] FIG. 1 is a schematic diagram showing a combination of a positive electrode, a negative electrode, a separator, a reference electrode, and a surface electrode according to an embodiment of the present disclosure. [Figure 4] 1 is a schematic diagram illustrating a self-heating control system for a charge / discharge battery according to an embodiment of the present disclosure. [Figure 5] FIG. 1 is a schematic diagram of an electrode lead-out cell according to an embodiment of the present disclosure. [Figure 6] FIG. 1 is a schematic diagram illustrating connections of a cell, a battery management unit, and an insulated gate bipolar transistor according to an embodiment of the present disclosure. [Figure 7] FIG. 2 is a block diagram of a processor, memory, communication interface, and communication bus according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, the embodiments of the present disclosure will be described in detail, and examples of the embodiments are shown in the drawings, where the same or similar reference numerals throughout represent the same or similar parts or parts having the same or similar functions. The embodiments described below with reference to the drawings are merely illustrative and are intended to help interpret the present disclosure, and should not be understood as limiting the present disclosure.

[0028] Hereinafter, a method for controlling self-heating of a charge / discharge battery according to an embodiment of the present disclosure will be described with reference to FIGS.

[0029] As shown in FIGS. 1 to 7, in the self-heating control method for a charge-discharge battery according to the embodiment of the present disclosure, the charge-discharge battery includes a cell, a separator is provided between the positive electrode and the negative electrode of the cell, a reference electrode is provided corresponding to the separator, and a surface electrode is provided corresponding to the surface of the negative electrode of the cell, the reference electrode is electronically insulated from the positive electrode and the negative electrode of the cell but is ionically conductive, and the surface electrode is in direct contact with the negative electrode of the cell to form a stable electrode. surfaceThe reference electrode outputs a potential. Furthermore, the reference electrode may be made of materials such as copper, aluminum, lithium, lithium iron phosphate, graphene, carbon nanotubes, silver, silver chloride, etc., but the present disclosure is not limited thereto, and the reference electrode may be made of materials that perform the same function as the above materials. Furthermore, the surface electrode establishes an electronic contact path by directly contacting the negative electrode, and is not limited to metal or non-metal conductors, and the surface electrode may be made of materials such as graphene, carbon nanotubes, carbon-based two-dimensional materials, or other materials with good electronic conductivity.

[0030] The self-heating control method according to the embodiment of the present disclosure includes step S01 and step S02.

[0031] In S01, the potential difference between the reference electrode and the surface electrode is detected.

[0032] The battery management device is connected to the reference electrode and the surface electrode, respectively, and detects the potential difference between the reference electrode and the surface electrode. Furthermore, the battery management device can detect the potential difference between the reference electrode and the surface electrode located at different positions of the cell.

[0033] In S02, a charging current adjustment command is generated based on the potential difference between the reference electrode and the surface electrode, and the charging current of the charging / discharging battery is adjusted based on the charging current adjustment command during the self-heating process of the charging / discharging battery.

[0034] Furthermore, the battery management device generates a charging current adjustment command based on the potential difference between the reference electrode and the surface electrode, and can adjust the charging current of the charging / discharging battery based on the charging current adjustment command during the self-heating process of the charging / discharging battery.

[0035] Specifically, the battery management device detects a potential difference between the reference electrode and the surface electrode, and then generates a charge current adjustment command based on the potential difference between the reference electrode and the surface electrode, thereby adjusting the charge current of the charge-discharge battery based on the charge current adjustment command during the self-heating process of the charge-discharge battery. Preset data may be stored within the battery management device, and the battery management device detects a potential difference between the reference electrode and the surface electrode, compares the potential difference with the preset data, and then generates a charge current adjustment command. By adjusting the charge current of the charge-discharge battery based on the charge current adjustment command during the self-heating process of the charge-discharge battery, the charge current of the charge-discharge battery is dynamically adjusted, preventing lithium deposition, which is caused by a large-amplitude self-heating current destroying the positive and negative electrode active materials of the battery, and avoiding the occurrence of lithium deposition in the battery, thereby improving the cycle life and safety of the battery.

[0036] As a result, the self-heating control method for a charge / discharge battery described above can uniformly heat the battery, prevent lithium deposition in the battery, and improve the cycle life and safety of the battery.

[0037] In some embodiments of the present disclosure, generating a charge current adjustment command based on the potential difference between the reference electrode and the surface electrode may include generating a charge current adjustment command with a charge current amplitude value of zero by a battery management device when the potential difference between the reference electrode and the surface electrode is less than a first potential threshold. When the reference electrode and the surface electrode are disposed at different positions in the cell, the battery management device can detect multiple potential differences, and when any one of the multiple potential differences is less than the first potential threshold, the battery management device generates a charge current adjustment command with a charge current amplitude value of zero. During the self-heating process of a charge / discharge battery, when the charge current amplitude value is zero, there is thermodynamically no possibility of lithium deposition from the charge / discharge battery. Therefore, when the potential difference between the reference electrode and the surface electrode is less than the first potential threshold, a charge current adjustment command with a charge current amplitude value of zero is generated, and the charge current of the charge / discharge battery is adjusted to zero, thereby actively reducing the charge current of the charge / discharge battery, thereby preventing lithium deposition from occurring in the charge / discharge battery.

[0038] Furthermore, when the potential difference between the reference electrode and the surface electrode is equal to or greater than the first potential threshold and less than the second potential threshold, a charge current adjustment command is generated based on the first potential threshold and the potential difference between the reference electrode and the surface electrode, thereby preventing lithium precipitation from occurring in the charge / discharge battery. When the reference electrode and the surface electrode are disposed at different positions in the cell, the battery management device can detect multiple potential differences, and when any one of the multiple potential differences is equal to or greater than the first potential threshold and less than the second potential threshold, a charge current adjustment command is generated based on the first potential threshold and the potential difference between the reference electrode and the surface electrode, thereby preventing lithium precipitation from occurring in the charge / discharge battery.

[0039] Furthermore, when the potential difference between the reference electrode and the surface electrode is greater than or equal to the first potential threshold and less than the second potential threshold, Determine a charging current amplitude value corresponding to the charging current adjustment command according to the formula: I_dc=I_dc0*f(s1)*(VN-E_plating); where s1 is the first safety parameter, f(s1) is a function of s1, I_dc is the charging current amplitude, I_dc0 is the initial charging current amplitude, VN is the potential difference between the reference electrode and the surface electrode, and E_plating is the first potential threshold. Note that f(s1) is a function of s1, and its value may be 0 to 10, may be set to a fixed value based on a prior experiment, or may be determined by table lookup. f(s1) depends on the charge / discharge capacity specific to the battery, and may be determined experimentally during countermeasure testing. It may be a fixed value or a function. The overall tendency of f(s1) is that batteries with high charge / discharge capacity have large f(s1) values ​​and batteries with low charge / discharge capacity have small f(s1) values. During the self-heating process of a charging / discharging battery, by determining the charging current amplitude value corresponding to the charging current adjustment command based on the above formula, it is possible to effectively avoid the occurrence of lithium precipitation in the charging / discharging battery during the charging process, and further improve the cycle life and safety of the battery.

[0040] In some embodiments of the present disclosure, the first potential threshold is determined based on the following steps: detecting a potential difference between the negative electrode of the cell and a reference electrode, and further detecting potential differences between the reference electrode and all negative electrodes; obtaining negative electrode potential curves at different charge rates based on the potential differences between the negative electrode of the cell and the reference electrode, and obtaining a relationship between the lithium deposition potential and the charge rate based on the negative electrode potential curves at different charge rates; and determining the first potential threshold based on the relationship between the lithium deposition potential and the charge rate. By setting the first potential threshold in this manner, it is possible to accurately determine the first potential threshold, effectively prevent lithium deposition from occurring in the charge-discharge battery during charging, and further improve the cycle life and safety of the battery.

[0041] In some embodiments of the present disclosure, when the potential difference between the reference electrode and the surface electrode is equal to or greater than the second potential threshold, the charging / discharging battery is not heated, and the charging current of the charging / discharging battery is adjusted according to the adjustment of the vehicle controller. This setting can effectively prevent lithium deposition from occurring in the charging / discharging battery during the charging process, and further improve the cycle life and safety of the battery.

[0042] In some embodiments of the present disclosure, when the potential difference between the reference electrode and the surface electrode is less than a first potential threshold, the self-heating control method may further include step S10 and step S20.

[0043] In S10, the potential difference between the positive electrode of the cell and the reference electrode is detected, and the potential difference between the positive electrode of the cell and the reference electrode can be detected by the battery management device.

[0044] In S20, a battery heating current adjustment command is generated based on the potential difference between the positive electrode and the reference electrode of the cell, thereby adjusting the heating current amplitude value of the charging / discharging battery based on the battery heating current adjustment command during the self-heating process of the charging / discharging battery.The battery management device can adjust the heating current amplitude value of the charging / discharging battery based on the battery heating current adjustment command during the self-heating process of the charging / discharging battery by generating the battery heating current adjustment command based on the potential difference between the positive electrode and the reference electrode of the cell.

[0045] Specifically, the battery management device detects a potential difference between the positive electrode of the cell and a reference electrode, and then generates a battery heating current adjustment command based on the potential difference between the positive electrode of the cell and the reference electrode, thereby adjusting the heating current amplitude of the charging / discharging battery based on the battery heating current adjustment command during the self-heating process of the charging / discharging battery. Preset data may be stored in the battery management device, and the battery management device detects a potential difference between the positive electrode of the cell and the reference electrode, compares the potential difference with the preset data, and then generates a battery heating current adjustment command. By adjusting the heating current amplitude of the charging / discharging battery based on the battery heating current adjustment command during the self-heating process of the charging / discharging battery, the heating current amplitude of the charging / discharging battery can be adjusted in real time, the charging / discharging battery can be heated uniformly, and the positive electrode active material of the charging / discharging battery can be prevented from being destroyed by a current with a large heating current amplitude, thereby further improving the cycle life and safety of the battery.

[0046] In some embodiments of the present disclosure, generating a battery heating current adjustment command based on the potential difference between the positive electrode and the reference electrode of the cell may include generating a battery heating current adjustment command with a heating current amplitude value of zero when the potential difference between the positive electrode and the reference electrode of the cell is greater than a third potential threshold. When the reference electrode and the surface electrode are disposed at different positions on the cell, the battery management device can detect multiple potential differences and generate a battery heating current adjustment command with a heating current amplitude value of zero when any one of the multiple potential differences is greater than the third potential threshold. During the self-heating process of a charging / discharging battery, generating a battery heating current adjustment command with a heating current amplitude value of zero when the potential difference between the positive electrode and the reference electrode of the cell is greater than the third potential threshold, and adjusting the battery heating current of the charging / discharging battery to zero and actively reducing the heating current of the charging / discharging battery can further avoid the destruction of the positive electrode active material of the charging / discharging battery due to a current with a large heating current amplitude value, uniformly heat the charging / discharging battery, and further improve the cycle life and safety of the battery.

[0047] When the potential difference between the positive electrode of the cell and the reference electrode is greater than the fourth potential threshold and less than or equal to the third potential threshold, the battery heating current adjustment command is generated based on the third potential threshold and the potential difference between the positive electrode of the cell and the reference electrode. When the reference electrode and the surface electrode are arranged at different positions on the cell, the battery management device can detect multiple potential differences, and when any one of the multiple potential differences is greater than the fourth potential threshold and less than or equal to the third potential threshold, the battery heating current adjustment command is generated based on the third potential threshold and the potential difference between the positive electrode of the cell and the reference electrode.

[0048] In some embodiments of the present disclosure, when a potential difference between the positive electrode and the reference electrode of the cell is greater than a fourth potential threshold and less than or equal to a third potential threshold, or when any one of the plurality of potential differences is greater than a fourth potential threshold and less than or equal to a third potential threshold, Determine a heating current amplitude value corresponding to the battery heating current adjustment command according to the formula: I_ac=I_ac0*f(s2)*(VP-E_max); where s2 is the second safety parameter, f(s2) is a function of s2, I_ac is the heating current amplitude value, I_ac0 is the initial heating current amplitude value, VP is the potential difference between the positive electrode and the reference electrode of the cell, and E_max is the third potential threshold.

[0049] Depending on safety needs, f(s2) is a function of s2, and its value may be 0 to 10, may be set to a fixed value based on prior experiments, or may be determined by looking up a table. During the self-heating process of a charge / discharge battery, the battery heating current adjustment command is determined based on the above formula to adjust the heating current amplitude of the charge / discharge battery, thereby heating the charge / discharge battery uniformly, further avoiding the occurrence of destruction of the positive electrode active material of the charge / discharge battery due to a current with a large heating current amplitude, and further improving the cycle life and safety of the battery.

[0050] A computer-readable storage medium according to an embodiment of the present disclosure stores a self-heating control program for a rechargeable / dischargeable battery that, when executed by a processor, realizes the self-heating control method for a rechargeable / dischargeable battery according to the embodiment.

[0051] According to a computer-readable storage medium according to an embodiment of the present disclosure, a potential difference between a reference electrode and a surface electrode is detected, and a charge current adjustment command is generated based on the potential difference between the reference electrode and the surface electrode. By adjusting the charge current of the charge-discharge battery based on the charge current adjustment command during the self-heating process of the charge-discharge battery, the battery can be heated uniformly, lithium precipitation can be avoided in the battery, and the cycle life and safety of the battery can be improved.

[0052] A battery management device 30 according to an embodiment of the present disclosure includes a memory 1203, a processor 1201, and a self-heating control program for a chargeable / dischargeable battery that is stored in the memory 1203 and executable by the processor 1201, and when the processor 1201 executes the self-heating control program for a chargeable / dischargeable battery, the self-heating control method for a chargeable / dischargeable battery according to the above embodiment is realized.

[0053] In the battery management device 30 according to an embodiment of the present disclosure, the processor 1201 executes a self-heating control program for a chargeable / dischargeable battery stored in the memory 1203, and adjusts the charging current of the chargeable / dischargeable battery based on a charging current adjustment command during the self-heating process of the chargeable / dischargeable battery, thereby uniformly heating the battery, preventing lithium deposition in the battery, and improving the cycle life and safety of the battery.

[0054] As shown in FIG. 7, the battery management device 30 includes at least one processor 1201, at least one communication interface 1202, at least one memory 1203, and at least one communication bus 1204, and in an embodiment of the present disclosure, the number of the processor 1201, the communication interface 1202, the memory 1203, and the communication bus 1204 is at least one, and the processor 1201, the communication interface 1202, and the memory 1203 communicate with each other via the communication bus 1204.

[0055] The memory 1203 may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read only memory (PROM), an erasable programmable read only memory (EPROM), an electrically erasable programmable read only memory (EEPROM), etc. The memory 1203 stores a program, and the processor 1201 executes the program after receiving an execution instruction to implement the steps of the air conditioning control method described in the above embodiment.

[0056] The processor 1201 may be an integrated circuit chip having signal processing capabilities. The processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc., or may be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. Each method, step, and logic block diagram disclosed in the embodiments of the present disclosure may be realized or executed. The general-purpose processor may be a microprocessor, any conventional processor, etc.

[0057] It should be noted that the logic and / or steps depicted in flowcharts or otherwise described in this disclosure may be considered, for example, as an ordered list of executable instructions for implementing logical functions, and may be tangibly embodied in any computer-readable medium for use by or in combination with an instruction execution system, device, or apparatus (e.g., a computer-based system, a processor-including system, or other system capable of reading instructions from and executing instructions from an instruction execution system, device, or apparatus). As used herein, a "computer-readable medium" may be any device that can store, store, communicate, propagate, or transmit a program for use by or in combination with an instruction execution system, device, or apparatus. More specific examples (non-exhaustive list) of computer-readable storage media include an electrical connection having one or more wires (electronic device), a portable computer disk box (magnetic device), random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), fiber optic device, and portable read-only memory (CD-ROM). The computer-readable storage medium may also be paper or other suitable medium on which the program may be printed, such that the program may be obtained electronically and thereafter stored in computer memory, for example, by optically scanning the paper or other medium and then editing, interpreting, or processing in any other suitable manner as required.

[0058] It should be understood that each part of the present disclosure can be realized by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be realized by software or firmware stored in a memory and executed by an appropriate instruction execution system. For example, when realized by hardware, as in other embodiments, it can be realized by any one or combination of techniques known in the art, such as a discrete logic circuit having logic gate circuits for implementing logic functions on data signals, an application specific integrated circuit having appropriate combinational logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0059] As shown in FIGS. 1 to 6 , a self-heating control system for a charge-discharge battery according to an embodiment of the present disclosure implements the self-heating control method for a charge-discharge battery according to the above embodiment. The self-heating control system includes a reference electrode 10, a surface electrode 20, and a battery management device 30. The reference electrode 10 is provided corresponding to a separator 43 between a positive electrode 41 and a negative electrode 42 of a cell 40 in the charge-discharge battery, and the surface electrode 20 is provided corresponding to the surface of the negative electrode 42 of the cell 40. Furthermore, the reference electrode 10 may be made of copper, aluminum, lithium, lithium iron phosphate, graphene, carbon nanotubes, silver, silver chloride, or other materials that perform the same functions as the above materials. Furthermore, the surface electrode 20 directly contacts the negative electrode 42 to establish an electronic contact path. The material for the surface electrode 20 is not limited to a metal or non-metal conductor; it may be made of graphene, carbon nanotubes, a carbon-based two-dimensional material, or other materials with good electronic conductivity.

[0060] The battery management device 30 is the battery management device 30 according to the above embodiment, and is connected to the reference electrode 10 and the surface electrode 20, respectively, detects the potential difference between the reference electrode 10 and the surface electrode 20, and generates a charge current adjustment command based on the potential difference between the reference electrode 10 and the surface electrode 20, thereby adjusting the charge current of the charge / discharge battery based on the charge current adjustment command during the self-heating process of the charge / discharge battery. Furthermore, the battery management device can detect the potential difference between the reference electrode and the surface electrode located at different positions of the cell.

[0061] Specifically, the battery management unit 30 detects the potential difference between the reference electrode 10 and the surface electrode 20, and then generates a charge current adjustment command based on the potential difference between the reference electrode 10 and the surface electrode 20, thereby adjusting the charge current of the charge-discharge battery based on the charge current adjustment command during the self-heating process of the charge-discharge battery. Preset data may be stored in the battery management unit 30, and the battery management unit 30 detects the potential difference between the reference electrode 10 and the surface electrode 20, compares the potential difference with the preset data, and then generates a charge current adjustment command. By dynamically adjusting the charge current of the charge-discharge battery based on the charge current adjustment command during the self-heating process of the charge-discharge battery, the battery can be prevented from undergoing lithium deposition due to a large-amplitude self-heating current that destroys the active materials of the positive electrode 41 and the negative electrode 42 of the battery. This prevents lithium deposition from occurring in the battery, thereby improving the cycle life and safety of the battery.

[0062] In some embodiments of the present disclosure, the reference electrode 10 is electrically insulated from the positive electrode 41 and the negative electrode 42 of the cell 40 but is ionically conductive, and the surface electrode 20 is in direct contact with the negative electrode 42 of the cell 40, outputting a stable reference potential as a stable electrode.

[0063] In some embodiments of the present disclosure, a charge / discharge battery may include multiple cells 40, and at least one cell 40 may include multiple reference electrodes 10 and multiple surface electrodes 20, with the surface electrodes 20 directly contacting the negative electrode 42 to establish an electronic contact path and detect the local surface potential of the cell 40.

[0064] In some embodiments of the present disclosure, the cell 40 may be provided with lead-out portions for leading out the surface electrode 20 and the reference electrode 10, thereby connecting the surface electrode 20 and the reference electrode 10 to the battery management device 30, making it easy for the battery management device 30 to detect the potential difference between the reference electrode 10 and the surface electrode 20.

[0065] In some embodiments of the present disclosure, the positions of the reference electrode 10 and the surface electrode 20 generally follow the principle of maximum temperature difference. Preferably, the reference electrode 10 and the surface electrode 20 are disposed in the cell 40 where the temperature difference within the charge-discharge battery is large, and may be disposed at the center of the cell 40. However, the present disclosure is not limited thereto, and the reference electrode 10 and the surface electrode 20 may be disposed at a distal end position away from an external heat source within the cell 40, or at the bottom of the cell 40. By disposing them in this way, the positions of the reference electrode 10 and the surface electrode 20 can be rationalized, lithium deposition in the battery can be avoided, the charge-discharge battery can be uniformly heated, and the cycle life and safety of the battery can be further improved.

[0066] In some embodiments of the present disclosure, the self-heating control system may include an insulated gate bipolar transistor (IGBT), which can output heating current signals of different frequencies and amplitudes in real time based on an external input. The IGBT may be connected to the battery management unit 30 and to the positive and negative electrode tabs 44 and 45 of the cell 40, and the battery management unit 30 dynamically adjusts the IGBT to output the frequency or current amplitude to the cell 40 according to a preset policy.

[0067] In the present disclosure, the battery management device 30 detects the potential difference between the negative electrode 42 and the reference electrode 10, and between the positive electrode 41 and the reference electrode 10, thereby preventing lithium deposition caused by a large-amplitude self-heating current that destroys the active material in the positive electrode 41 and the active material in the negative electrode 42 of the battery, and ensuring that the cycle life and safety performance of the cell 40 are not affected. In addition, the provision of the reference electrode 10 and the surface electrode 20 makes it possible to detect the local potential distribution of the cell 40 during self-heating.

[0068] One of the biggest problems with self-heating technology is that it mainly utilizes the electronic impedance of the metal conductor (or current collector) because the frequency of self-heating is generally high. The current density in the cell 40 is usually distributed with a gradient along the direction of the current collector. Also, the heat generation of the current collector of the battery is expressed as Q=I based on the ohmic heating equation. 2* R, heat generation is very severe near the draw-out portion of the cell 40, and heating at low temperatures becomes uneven, with the temperature difference between the cold side and the hot side reaching 30°C to 50°C. Therefore, dynamically detecting the local potential of the cell 40, particularly the local potential detected by simultaneously placing the reference electrode 10 and the surface electrode 20 at locations away from heat sources such as the center and bottom of the cell 40 where lithium is likely to deposit, is important for determining whether the current self-heating condition poses a significant risk.

[0069] Furthermore, the reference electrode 10 can output a stable standard potential that is not affected by local potentials, and the surface electrode 20 can output a changed surface potential that directly reflects the local potential. By detecting the potential difference between the negative electrode 42 and the reference electrode 10, lithium deposition in the cell 40 can be prevented. By detecting the potential difference between the positive electrode 41 and the reference electrode 10, destruction of the active material in the battery's positive electrode 41 due to a self-heating current with a large amplitude can be prevented. When the potential of the positive electrode 41 is detected to be higher or lower than a predetermined range, the self-heating amplitude is automatically reduced until the detection signal falls below a preset threshold.

[0070] The reference electrode 10 is generally made of a material that has a stable electrochemical reaction, and its potential is generally not affected by the surrounding environment and conditions, so that it can output a stable reference potential.

[0071] The surface electrode 20, i.e., the surface electrode 20 in the present disclosure, is a conductor, particularly having electronic conductivity. When it comes into contact with the active material of the positive electrode 41 or the negative electrode 42, its potential automatically coincides with the Fermi level of the positive electrode 41 or the negative electrode 42, thereby achieving the purpose of dynamically detecting the electrochemical potential of the active material.

[0072] In some embodiments of the present disclosure, generating a charge current adjustment command based on the potential difference between the reference electrode 10 and the surface electrode 20 may include generating a charge current adjustment command with a charge current amplitude value of zero by the battery management unit 30 when the potential difference between the reference electrode 10 and the surface electrode 20 is smaller than a first potential threshold. When the reference electrode 10 and the surface electrode 20 are disposed at different positions of the cell 40, the battery management unit 30 can detect multiple potential differences, and when any one of the multiple potential differences is smaller than the first potential threshold, the battery management unit 30 generates a charge current adjustment command with a charge current amplitude value of zero. During the self-heating process of the charge-discharge battery, when the charge current amplitude value is zero, there is no thermodynamic possibility of lithium precipitation from the charge-discharge battery. When the potential difference between the reference electrode 10 and the surface electrode 20 is smaller than the first potential threshold, a charge current adjustment command with a charge current amplitude value of zero is generated, and the charge current of the charge-discharge battery is adjusted to zero, and the charge current of the charge-discharge battery is actively reduced, thereby preventing the occurrence of lithium precipitation in the charge-discharge battery.

[0073] Furthermore, when the potential difference between the reference electrode 10 and the surface electrode 20 is equal to or greater than the first potential threshold and smaller than the second potential threshold, a charge current adjustment command is generated based on the first potential threshold and the potential difference between the reference electrode 10 and the surface electrode 20, thereby preventing lithium precipitation from occurring in the charge / discharge battery. When the reference electrode 10 and the surface electrode 20 are disposed at different positions in the cell 40, the battery management device 30 can detect multiple potential differences, and when any one of the multiple potential differences is equal to or greater than the first potential threshold and smaller than the second potential threshold, a charge current adjustment command is generated based on the first potential threshold and the potential difference between the reference electrode 10 and the surface electrode 20, thereby preventing lithium precipitation from occurring in the charge / discharge battery.

[0074] Furthermore, when the potential difference between the reference electrode 10 and the surface electrode 20 is equal to or greater than the first potential threshold and less than the second potential threshold, Determine a charging current amplitude value corresponding to the charging current adjustment command according to the formula: I_dc=I_dc0*f(s1)*(VN-E_plating); where s1 is the first safety parameter, f(s1) is a function of s1, I_dc is the charging current amplitude, I_dc0 is the initial charging current amplitude, VN is the potential difference between the reference electrode 10 and the surface electrode 20, and E_plating is the first potential threshold. Note that f(s1) is a function of s1, and its value may be 0 to 10, or may be set to a fixed value based on a prior experiment, or may be determined by table lookup. f(s1) depends on the charge / discharge capacity specific to the battery, and a specific value may be determined experimentally during countermeasure testing, or it may be a fixed value or a function. The overall tendency of f(s1) is that batteries with high charge / discharge capacity have large f(s1) values, and batteries with low charge / discharge capacity have small f(s1) values. During the self-heating process of a charging / discharging battery, by determining the charging current amplitude value corresponding to the charging current adjustment command based on the above formula, it is possible to effectively avoid the occurrence of lithium precipitation in the charging / discharging battery during the charging process, and further improve the cycle life and safety of the battery.

[0075] In some embodiments of the present disclosure, the first potential threshold is determined based on the following steps: detecting a potential difference between the negative electrode 42 of the cell 40 and the reference electrode 10, and further detecting potential differences between the reference electrode 10 and all negative electrodes 42; obtaining potential curves for the negative electrode 42 at different charge rates based on the potential differences between the negative electrode 42 of the cell 40 and the reference electrode 10, and obtaining a relationship between the lithium deposition potential and the charge rate based on the potential curves for the negative electrode 42 at different charge rates; and determining the first potential threshold based on the relationship between the lithium deposition potential and the charge rate. This setting allows the first potential threshold to be accurately determined, effectively preventing lithium deposition from occurring in the charge-discharge battery during charging, and further improving the cycle life and safety of the battery.

[0076] In some embodiments of the present disclosure, when the potential difference between the reference electrode 10 and the surface electrode 20 is equal to or greater than the second potential threshold, the charging / discharging battery is not heated, and the charging current of the charging / discharging battery is adjusted according to the adjustment of the vehicle controller. This setting can effectively prevent lithium deposition from occurring in the charging / discharging battery during the charging process, and further improve the cycle life and safety of the battery.

[0077] In some embodiments of the present disclosure, when the potential difference between the reference electrode 10 and the surface electrode 20 is less than the first potential threshold, the self-heating control method may further include step S10 and step S20.

[0078] In S10, the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10 is detected, and the battery management device 30 can detect the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10.

[0079] In S20, a battery heating current adjustment command is generated based on the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10, thereby adjusting the heating current amplitude value of the charge / discharge battery based on the battery heating current adjustment command during the self-heating process of the charge / discharge battery. By generating a battery heating current adjustment command based on the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10, the battery management device 30 can adjust the heating current amplitude value of the charge / discharge battery based on the battery heating current adjustment command during the self-heating process of the charge / discharge battery.

[0080] Specifically, the battery management unit 30 detects the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10, and then generates a battery heating current adjustment command based on the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10, thereby adjusting the heating current amplitude of the battery during the self-heating process of the battery during charging and discharging based on the battery heating current adjustment command. Preset data may be stored in the battery management unit 30, and the battery management unit 30 detects the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10, compares the potential difference with the preset data, and then generates a battery heating current adjustment command. By adjusting the heating current amplitude of the battery during the self-heating process of the battery during charging and discharging based on the battery heating current adjustment command, the heating current amplitude of the battery during charging and discharging can be adjusted in real time, the battery can be heated uniformly, and the active material of the positive electrode 41 of the battery can be prevented from being destroyed by a current with a large heating current amplitude, thereby further improving the cycle life and safety of the battery.

[0081] In some embodiments of the present disclosure, generating a battery heating current adjustment command based on the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10 may include generating a battery heating current adjustment command with a heating current amplitude value of zero when the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10 is greater than a third potential threshold. When the reference electrode 10 and the surface electrode 20 are disposed at different positions of the cell 40, the battery management device 30 can detect multiple potential differences, and generate a battery heating current adjustment command with a heating current amplitude value of zero when any one of the multiple potential differences is greater than the third potential threshold. During the self-heating process of the charge-discharge battery, when the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10 is greater than the third potential threshold, a battery heating current adjustment command with a heating current amplitude value of zero is generated to adjust the battery heating current of the charge-discharge battery, adjust the battery heating current of the charge-discharge battery to zero, and actively reduce the heating current of the charge-discharge battery, thereby further avoiding the destruction phenomenon of the positive electrode 41 active material of the charge-discharge battery caused by current with a large heating current amplitude value, heating the charge-discharge battery uniformly, and further improving the cycle life and safety of the battery.

[0082] When the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10 is greater than the fourth potential threshold and less than or equal to the third potential threshold, a battery heating current adjustment command is generated based on the third potential threshold and the potential difference between the positive electrode 41 of the cell and the reference electrode 10. When the reference electrode 10 and the surface electrode 20 are disposed at different positions in the cell, the battery management device can detect multiple potential differences, and when any one of the multiple potential differences is greater than the fourth potential threshold and less than or equal to the third potential threshold, a battery heating current adjustment command is generated based on the third potential threshold and the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10.

[0083] In some embodiments of the present disclosure, when the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10 is greater than a fourth potential threshold and less than or equal to a third potential threshold, or when any one of the multiple potential differences is greater than a fourth potential threshold and less than or equal to a third potential threshold, Determine a heating current amplitude value corresponding to the battery heating current adjustment command according to the formula: I_ac=I_ac0*f(s2)*(VP-E_max); where s2 is the second safety parameter, f(s2) is a function of s2, I_ac is the heating current amplitude value, I_ac0 is the initial heating current amplitude value, VP is the potential difference between the positive electrode 41 of the cell 40 and the reference electrode 10, and E_max is the third potential threshold.

[0084] Depending on safety needs, f(s2) is a function of s2, and its value may be 0 to 10, may be set to a fixed value based on prior experiments, or may be determined by looking up a table. During the self-heating process of a charge / discharge battery, the battery heating current adjustment command is determined based on the above formula to adjust the heating current amplitude of the charge / discharge battery, thereby heating the charge / discharge battery uniformly, further avoiding the occurrence of destruction of the positive electrode 41 active material of the charge / discharge battery due to a current with a large heating current amplitude, and further improving the cycle life and safety of the battery.

[0085] In the description herein, a description that refers to terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present disclosure. In the description herein, the exemplary use of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined as appropriate in any one or more embodiments or examples.

[0086] Although embodiments of the present disclosure have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present disclosure, and that the scope of the present disclosure is limited only by the claims and their equivalents. [Explanation of symbols]

[0087] 10 Reference electrode 20 Surface electrode 30 Battery management device 40 cells 41 Positive electrode 42 Negative electrode 43 Separator 44 Positive electrode tab 45 Negative electrode tab 50 Insulated Gate Bipolar Transistor 1201 processor 1202 Communication Interface 1203 memory 1204 communication bus

Claims

1. A method for controlling self-heating in a charge-discharge battery, the charge-discharge battery including a cell (40), a separator (43) disposed between a positive electrode (41) and a negative electrode (42) of the cell, a reference electrode (10) disposed corresponding to the separator, and a surface electrode (20) disposed corresponding to a surface of the negative electrode of the cell, the method comprising: detecting a potential difference between the reference electrode and the surface electrode; generating a charge current adjustment command based on the potential difference between the reference electrode and the surface electrode, and adjusting the charge current of the charge / discharge battery based on the charge current adjustment command during the self-heating process of the charge / discharge battery.

2. generating a charging current adjustment command based on a potential difference between the reference electrode and the surface electrode; generating a charging current adjustment command having a charging current amplitude value of zero when the potential difference between the reference electrode and the surface electrode is less than a first potential threshold; 2. The method for controlling self-heating of a charge / discharge battery according to claim 1, further comprising: when the potential difference between the reference electrode and the surface electrode is equal to or greater than a first potential threshold and smaller than a second potential threshold, generating a charge current adjustment command based on the first potential threshold and the potential difference between the reference electrode and the surface electrode.

3. when the potential difference between the reference electrode and the surface electrode is greater than or equal to a first potential threshold and less than a second potential threshold; Determine a charging current amplitude value corresponding to the charging current adjustment command according to the formula: I_dc=I_dc0*f(s1)*(VN-E_plating); 3. The self-heating control method for a charge-discharge battery according to claim 2, wherein s1 is a first safety parameter, f(s1) is a function of s1, I_dc is the charging current amplitude value, I_dc0 is the initial charging current amplitude value, VN is the potential difference between the reference electrode and the surface electrode, and E_plating is the first potential threshold.

4. The first potential threshold is detecting a potential difference between the negative electrode of the cell and the reference electrode; Obtaining a negative electrode potential curve at different charge rates based on a potential difference between the negative electrode of the cell and the reference electrode, and obtaining a relationship between a lithium deposition potential and a charge rate based on the negative electrode potential curve at different charge rates; The method for controlling self-heating of a charge / discharge battery according to claim 2 , wherein the first potential threshold is determined based on a relationship between the lithium deposition potential and a charge rate.

5. If the potential difference between the reference electrode and the surface electrode is less than a first potential threshold, the method comprises: detecting a potential difference between the positive electrode of the cell and the reference electrode; 3. The method for controlling self-heating of a charge-discharge battery according to claim 2, further comprising the steps of: generating a battery heating current adjustment command based on the potential difference between the positive electrode of the cell and the reference electrode; and adjusting a heating current amplitude value of the charge-discharge battery based on the battery heating current adjustment command during the self-heating process of the charge-discharge battery.

6. generating a battery heating current adjustment command based on a potential difference between the positive electrode of the cell and the reference electrode; generating a battery heating current adjustment command having a heating current amplitude value of zero when the potential difference between the positive electrode of the cell and the reference electrode is greater than a third potential threshold; 2. The method for controlling self-heating of a charge / discharge battery according to claim 1, further comprising: when the potential difference between the positive electrode of the cell and the reference electrode is greater than a fourth potential threshold and less than or equal to a third potential threshold, generating the battery heating current adjustment command based on the third potential threshold and the potential difference between the positive electrode of the cell and the reference electrode.

7. when the potential difference between the positive electrode of the cell and the reference electrode is greater than a fourth potential threshold and less than or equal to a third potential threshold; Determine a heating current amplitude value corresponding to the battery heating current adjustment command based on the formula: I_ac=I_ac0*f(s2)*(VP-E_max); 7. The self-heating control method for a charge-discharge battery according to claim 6, wherein s2 is a second safety parameter, f(s2) is a function of s2, I_ac is the heating current amplitude value, I_ac0 is the initial heating current amplitude value, VP is the potential difference between the positive electrode of the cell and the reference electrode, and E_max is the third potential threshold.

8. A computer-readable storage medium storing a program for controlling self-heating of a chargeable / dischargeable battery, which, when executed by a processor, performs the method for controlling self-heating of a chargeable / dischargeable battery according to any one of claims 1 to 7.

9. A battery management device comprising a memory (1203), a processor (1201), and a self-heating control program for a chargeable / dischargeable battery stored in the memory and executable by the processor, wherein when the processor executes the self-heating control program for a chargeable / dischargeable battery, the battery management device executes the self-heating control method for a chargeable / dischargeable battery described in any one of claims 1 to 7.

10. A self-heating control system for a charge / discharge battery, comprising: a reference electrode; a surface electrode; and a battery management device, the reference electrode is disposed in correspondence with a separator between a positive electrode and a negative electrode of a cell in the charge-discharge battery; the surface electrode is disposed corresponding to a surface of the negative electrode of the cell; The battery management device is connected to the reference electrode and the surface electrode, respectively, detects a potential difference between the reference electrode and the surface electrode, generates a charge current adjustment command based on the potential difference between the reference electrode and the surface electrode, and adjusts the charge current of the charge / discharge battery based on the charge current adjustment command during the self-heating process of the charge / discharge battery.

11. 11. The self-heating control system for a charge / discharge battery according to claim 10, wherein the reference electrode is electronically insulated from but ionically conductive with the positive and negative electrodes of the cell, and the surface electrode is in direct contact with and electronically conductive with the negative electrode of the cell.

12. A computer program for controlling self-heating of a chargeable / dischargeable battery, which, when executed by a processor, executes the method for controlling self-heating of a chargeable / dischargeable battery according to any one of claims 1 to 7.

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